Batteries and the Environment

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BATTERIES AND THE ENVIRONMENT Per Bro Southwest Electrochemical Company Santa Fe, NM 87501 USA. and Samuel C. Levy Sandia National Laboratories Albuquerque, NM 87185 U.SA

1. INTRODUCTION The awareness that batteries may pose environmental and health risks has been recognized since the toxicity of various battery materials became known. Lead is an example. It has been known for some time that the inhalation or ingestion of lead fumes and lead compounds from paint and automobile exhaust may cause damage to the central nervous system, and that exposures to lead-containing materials from any source, including batteries, should be limited. Although battery manufacturers began to recycle lead for economic reasons long before its harmful effects were fully recognized, the general awareness of its toxicity had led them to limit worker exposures and to limit the amount of lead discharged from their lants. The case of mercury is similar in some respects. Its toxicity was well known Pons before mercury batteries were developed. When mercu batteries first appeared, they caused little public concern, primarily because t eir distribution and use were quite limited. The mercury s ill at Minamata Bay in Japan, the growing use of mercurials as fungicides, and t e finding that mercury had become widely distributed in various ecosystems and had entered the food chain in various ways led to an increased concern regarding the possible spread of mercury from any source, including batteries. The case of cadmium is more recent even thou h cadmium has been used in Ni/Cd batteries ever since their invention in 1899. "ke reason for the belated awareness of cadmium as a toxic material is connected with the rowth of Ni/Cd batteries as a general consumer item. Indeed, the growth of pub ic concern about the possible toxic effects of batteries is closely connected with the rapid growth and ever widening distribution of batteries for consumer electronics applications and their subsequent appearance in municipal landfills in increasing amounts.

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It is not so much that the disposal of batteries in uncontrolled landfills has an immediate and serious effect on the environment. Rather, it is the recognition that their accumulation, and eventual entry into the environment, may cause harm. Regardless of when that may occur, it is thought advisable to take the necessary steps at the earliest possible time to prevent such an eventuality from occurring, preferably by recycling the batteries, even if there are no compelling short term economic incentives to do so.

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In the design of reprocessing facilities for high volume operations, conventional metallurgical techniques are employed to the fullest extent ossible. Both the simple thermal methods and the more complicated hydrometa lurgical techniques are used. As more restrictive limits are imposed on the allowable airborne, waterborne, and solid dischar es from plants, however, it seems inevitable that the more elaborate, the more efficient, and the more expensive chemical processing techniques will come to dominate the recycling field. The ideal objective is to operate fully closed loop facilities, apart from the materials to be rocessed, but that is a practical im ossibility. Instead, re clin o erations should e designed to satisfy two primary o jectives in regard to p ant isc arges:

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1. The concentration of toxic materials in all the waste streams must be below prescribed limits. 2. The total amounts of toxic materials discharged from a plant in specified time periods must be below prescribed limits. The rates of discharge are also important. In this chapter we introduce batteries in general, with few technical details. We consider the possible environmental impact of batteries relative to that of other sources of the same toxic materials, and we review briefly some re latory aspects of battery manufacture, recycling and disposal. Also included is a Ecussion of the possibility of developing new battery systems and modifications aimed at the design of environmentally friendly batteries. Various recycling schemes are discussed from an elementa point of view; expert readers are referred to the literature cited at the end oft e chapter for more detailed technical information.

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1.1 The Classification of Batteries

Many different kinds of batteries have been developed to serve a variety of needs in various markets. Based on their mode of operation, we distinguish between the following types of batteries: Primarv batteries are distinguished from others bv the characteristic feature of essentid non-rechargeability." They are discarded when their electrical energy has been consumed. Examples: Zinc Carbon, Alkaline Manganese, Silver/Zinc, Lithium/Manganese, Lithium/Sulfur ioxide, Lithium/Thionyl Chloride.

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- R Reserve batteries are a special type of primary battery distinguished by the feature that they need to be activated by mechanical or pyrotechnic means 'ust prior to use, whereby electrolyte is injected into the electrode chamber o f tlle batteries. They are discarded after a one-time use. Examples: Silver/Zinc, Water activated Magnesium/Lead Chloride, Ammonia activated Magnesium/Dinitrobenzene, Spin activated Lead/Fluoroboric Acid. Thermal Batteries Thermal batteries represent another e of primary reserve battery distinpished by the feature that they are activated y heating to a high temperature by internal

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pyrotechnic means. They operate only at high temperatures and are discarded after a single dischar e. Examples: CalciumfTungstic Oxide, Calcium/ Calcium Chromate, Lithium/Iron Sulfide. Fuel Cells Fuel cells represent another variant of primary batteries distinguished by the interesting feature that the oxidizin agent, the cathodic material, is oxygen taken from the surroundin air. These atteries must remain open to the air during operation. The meta /air fuel cells are discarded when their negative electrodes have been discharged. Examples: Aluminum/Air, Zinc/Air, Methanol/Air, Hydrogen/Oxygen.

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Secondary Batteries Secondary batteries are rechargeable batteries that can be re-used many times, several hundred times for consumer batteries and several thousand times for s ecially designed secondary batteries. Lamples: Nickel/Cadmium, Lead-Acid, Silver/Zinc, Nickel/Metal Hydride. Advanced B a t t h Other types of batteries have been developed, but, with some notable exceptions, they have not yet reached commercial importance. Among these, we may mention flow batteries and hi h tem erature solid state or fused salt batteries. Some of these batteries are rec argea le and some are suited for high capacity applications only. Examples: Zinc/Bromine, Sodium/Sulfur, Solid Electrolyte, and Polymer Systems.

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The distribution of the different types of batteries among various ap lications is an important consideration from the point of view of the control o their possible entry into the environment. Reserve and thermal batteries are used almost exclusively by military organizations and their disposal can, in principle, be controlled to a much higher degree than can the disposal of primary and secondary batteries used by the general ublic. A further classification may be considered for the rechargeable batteries. &e use and disposal of traction and automotive type batteries, as well as any kind of battery used by fleet operators, can, by the very nature of their users, be well controlled. In fact, a very large fraction of batteries entering into these cate ories of usage are already being recycled, rather than discarded in landfills. d e principal environmental problems are associated with the smaller size batteries, both primary and secondary, that are widely used by the general public in a variety of applications, and that are discarded in an uncontrolled manner.

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An interesting observation (1) is that the types of batteries used by the general

public in different countries may vary considerably. For example, the low cost zinc/carbon batteries are more prevalent in underdeveloped countries than are the more expensive alkaline manganese batteries. The latter are more important in highly developed countries. Battery usage appears to be closely coupled with the usage of consumer electronic devices. The product mix of batteries used in any particular country needs to be considered when battery recycling and disposal processes are designed for that country.

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1.2 Battery Life Cycles

The typical life cycles of consumer batteries depend to some extent on their applications. Primary batteries employed in portable devices are most often discarded casually with domestic trash and end up in landfills. Exceptions exist in communities where deliberate efforts are made to collect spent batteries for revcling or proper disposal and in communities where battery vendors partici ate in incentive programs to return spent batteries to the manufacturers or co lect them for recycling or proper disposal. The magnitude of such programs is still uite limited and has contributed little to alleviate the environmental problems %at may be created by the disposal of spent, primary consumer batteries.

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Small nickel/cadmium and lead-acid batteries generally experience the same fate. With some exceptions, the larger rechargeable batteries, automotive batteries in particular, are returned to the vendors to a large extent for subsequent recyclin by the manufacturers, or for processing by scrap metal operators for recovery o f t eir intrinsic metal values.

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During normal battery usage, there is no reason to expect the batte contents to leave the batteries and enter the environment in an uncontrol ed manner. Accidents do occur, however, due to inadvertent or deliberate abuse, or due to battery damage caused by other events such as collisions or fires. Occurrences of this kind may generate excessive local concentrations of toxic or harmful substances or other hazards, such as acid or alkali burns, toxic vapors, or explosions, with undesirable effects on nearby persons or on the local environment. Apart from the local and temporary effects, events of this kind are rare and do not significantlycontribute to environmental contamination in general. 1.3 Battery Materials

Most of the batteries available today are of a high quality, robust, and able to withstand a reasonable amount of abuse without rupturing or spilling their contents. Our concern is, therefore, less with what may happen durin normal more importantly, what is likely to happen when batteries are &carded whether in landfills or during recycling, and their contents enter the For the design of the proper handling, disposal, and recycling methods it is necessary to know what materials are contained in the batteries. We present a brief summary below of the major chemical species present in the most frequently used batteries. Information on the contents of less commonly used batteries may be obtained from their manufacturers or by chemical analyses of the batteries themselves. Zinc/Carbon Batteries (Regular and Heaw Duty Iron case, (tin and copper ma be present in sma1)amounts). Zinc anode, (may contain cadYmium and lead). Manganese dioxide cathode with some metal impurities. Carbon, acetylene black, and graphite. Ammonium chloride electrolyte, zinc chloride,(chromate may be present). Starch, paper, asphaltics, polypropylene. Alkaline Maneanese Batteries Nickel plated steel can (tin and copper may be present in small amounts).

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Zinc anode with unspecified corrosion inhibitors (very little mercury). Manganese dioxide cathode (high purity). Carbon, conductive component. Potassium hydroxide electrolyte with dissolved zinc oxide. Cellophane, nylon, carboxymethylcellulose. Silver Oxide Cells Essentially the same constituents as alkaline manganese cells, except that silver oxide has replaced manganese dioxide. Mercurv Cells Essentially the same constituents as alkaline manganese cells, except that mercuric oxide has replaced man anese dioxide. Silver may be present in the cathode. Mercury cells are being p ased out wherever feasible.

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Zinc/Air Cells Essentially the same constituents as alkaline manganese cells. excem that man anesedioxide is replaced with a catalytic electrode that may contain carbon, smal amounts of silver, manganese dioxide, and some heavy metals as catalysts in addition to teflon type binders.

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Lithium ManPanese Batteries Nickel plated steel case. Lithium anode with or without a metal screen. Manganese dioxide cathode (high urity). Carbon conductive component, te on binder. Polypropylene separator and insulators. Organic solvent electrolyte. (The solvents actually used may differ in cells from different manufacturers. Typically, they include propylene carbonate, dimethoxyethane, or similar solvents). Electrolytic salts such as lithium perchlorate, lithium hexafluoroarsenate, and lithium tetrafluoroborate.

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Thionyl Chloride Batteries Stainless steel or nickel plated steel case. Thionyl chloride active cathode material. Teflon bonded carbon current collector with nickel grid. Lithium aluminum chloride electrolytic salt. Fiber glass separator. Lead-Acid Batteries Pol ropylene or hard rubber case. Lea anode with antimony or calcium alloying constituents (Low concentrations of other metals may be present). Lead dioxide cathode. Sulfuric acid electrolyte. Polyvinyl chloride, polyolefins, phenolic bonded paper, epoxy sealants.

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Nickel-Cadmium Batteries Nylon, polypropylene, or stainless steel case. Nickel plated copper terminals. Cadmium anodes.

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Nickel oxyhydroxy cathodes. Potassium hydroxide electrolyte. Nylon or pol propylene separators (wetting agents may be present in low concentrations!. Nickel-Metal Hydride Batteries Essentially the same constituents as Ni/Cd batteries, except that cadmium and cadmium hydroxide have been replaced with a metal hydride formed from hydrogen and a mixture of metals that may contain nickel, cobalt, lanthanum, and various mischmetal components (rare earth metals). The approximate metal contents of various batteries in terms of weight percentages are as follows (2):

Pb-Acid Ni/Cd 1.4 Toxicity

The preceding list indicates the variety of materials that are employed in the many different types of batteries that are in use today and which are available to the eneral consumer. Some of these materials may cause harm to users if the atteries are grossly abused, i.e., under conditions not likely to occur unless deliberate attempts are made to abuse the batteries. Althou h mishaps ma occur due to inadvertent abuse, with few exce tions, batteries have een found to e very safe from the time they leave the manu acturers until their disposal.

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A different situation exists during battery manufacturing and during batte disposal/recycling operations where workers may come into direct contact wit toxic or harmful battery components. In addition, members of a community may be unknowingly exposed to toxic battery materials due to the improper disposal of battery wastes and the injection of toxic battery materials into their ecosystems. The latter may affect both man, animal, and plant life adverse1 . In general, the toxic effect of a particular material depends upon the nature ofythe exposure and its concentration; whether it be by contact, ingestion, inhalation, or a combination of these.

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Although the regulatory climate varies from one country to another, the manufacturing environments have been subject to more or less stringent state control for some time now in many of the countries where batteries are made. The regulations take into consideration the nature of the materials used, as far as is known, and they provide limits applicable to short term and lon term exposures as well as procedures and/or rules governing the handling andp discharge of toxic waste materials. Since battery manufacturing operations are reasonably well controlled in most countries where batteries are made and since the manufacturers are well aware of the hazards associated with their operations, the battery

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manufacturing aspects of the environmental problems will not be discussed here. It is only recently that attention has been drawn to the potential community hazards associated with the dis osal of batteries in general. We focus attention on the disposal/recycling aspects trlat may be of interest to the general public. The battery materials of foremost environmental concern at the present time are mercury, lead, and cadmium, but recent efforts have contributed significantly to the reduction of their dispersal in the environment. For example, the redesign of alkaline manganese batteries that contained an appreciable amount of mercury in the past has led to a new eneration of alkaline manganese batteries that are ractically free of mercury. %he recycling of lead-acid batteries has been practiced !or some time, and it has led to a significant reduction in the amount of lead that might otherwise have entered the environment. In the case of cadmium, much remains to be done, but the pending introduction of nickel/metal hydride batteries as a replacement for nickel/cadmium batteries may do much to alleviate this problem. For our purposes, there is no need to discuss the detailed medical and public health aspects of the toxic substances present in batteries. It is sufficient to recognize that their effects are many and varied, and that they may range from short term to long term effects, as well as long term-delayed effects due to the cumulative retention of the toxic substances or their derivatives in the bod . Information on the effects of many battery materials on human health is availab e in the comprehensive listing prepared by Sax and Lewis (3) and the references cited by them.

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The relative toxicit of a material may be expressed by the maximum allowed exposure in terms o the time weighted avera e exposure (TWA) or the threshold limit value (TLV) for short term exposures. f i e r e 1s a possibility that the currently acce ted values may be lowered as more information becomes available, especially on t e effects of long term, low level exposures. Some values selected from Sax and Lewis are:

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Lead Cadmium Mercury

TLV: 0.05 mg/ms

These values apply to workers exposed to battery processing operations, whether manufacturing, recycling, or disposal operations. The values ap licable to drinking water may be of greater interest to the general public. From t e Code of Federal Regulations in the United States we obtain the following values (4):

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Lead Cadmium Mercury

0.050 mg/l 0.010 mg/l 0.002 mg/l

The introduction of advanced batteries based on lithium or on metal hydride technologies has not yet reached the point where they have created an environmental concern, but when their usage becomes more widespread they will introduce additional problems. In particular, lithium batteries containin thionyl chloride (TLV = 1 ppm) or sulfur dioxide (TLV = 2 ppm) and acetonitri e (TWA = 40 ppm) may create disposal problems not only because of their toxicity, but also

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because of the fire hazard associated with lithium metal. In addition to various flammable organic solvents (for example methyl formate, tetrahydrofuran, and others), lithium batteries contain salts (lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium perchlorate, and others) and various heavy metals, some of which may create environmental problems, not so much at the user level as at the disposal/recyclin level. The metal hydrides that replace cadmium in Ni/Cd batteries a r e like y to contain heavy metals such as vanadium (V), lanthanum (La), cobalt (Co), and various misch metal components (cerium group metals with atomic numbers ranging from 58 through 71), some of which may be toxic.

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An important aspect of the battery problem is the question of the pathways of the

toxic battery materials in various ecosystems, whether they enter by leaching from landfills or via the atmosphere from incinerators. We do not discuss this difficult problem here. It is an area about which little is known, although work in progress is providin useful information of direct interest to both regulatory organizations and the pu lic in general. The reader is referred to the literature cited at the end of the chapter for information on this subject.

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THE ENVIRONMENTALPROBLEM

The problem created by the uncontrolled disposal of batteries may be stated simply: some batteries contain toxic materials whose injection into ecosystems may cause harm, When added to landfills, the toxic materials may enter the local groundwater system and propagate through the food chain in various ways. If processed in improperly designed or operated incinerators, the toxic materials may enter the ecosystem via the airborne route. Although the organic solvents and other materials in lithium batteries do not present a significant problem at this time, they may also cause harm if improperly processed after being discarded. The many factors that affect the athways of toxic materials in ecosystems are not well known. Therefore, it is fifficult to predict exactly how and when such materials may enter the foodchain and to quantify the magnitude of their harmful effects. Faced by the actual and potential threat to public health, the most reasonable policy is to prevent the potential entry of the toxic materials into ecosystems at the source. Apart from the long known toxicity of lead and the measures taken to decrease the hazards associated with the improper handling and disposal of lead-acid batteries, only recently has attention been focussed on the need to control the environmental release of other toxic batte materials. The most critical of these materials are cadmium and mercury. Ef orts underway in many countries today suggest that significant reductions will be achieved in the amounts of mercury and cadmium likely to be dischar ed into various ecosystems during the coming years. However, the uncontrolled (f!isposal of alkaline manganese and nickel-cadmium batteries during the ast years has added an unknown amount of mercury and cadmium to older land ills. Their distribution in various ecosystems represent a potential threat that is likely to persist for some time, even if no further additions of mercury or cadmium are made to existing landfills. These problems are more likely to be encountered in urban rather than rural communities and in communities near landfills. It is an open question whether the water purification methods practiced

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in vulnerable communities are effective in removing mercury, lead, cadmium, and other toxic materials originating from batteries and other wastes. We do not discuss the important problems associated with the secure containment of toxic materials in landfills nor the possibility of detoxifying landfills ( 5 ) . The serious nature of the health problems caused by the ingestion of mercury, cadmium, and lead is beyond uestion. However, sources other than batteries also contribute to the magnitude o the potential and actual health problems caused by these materials. Barnett and Wolsky (6) have collected information on the fractions of the total amounts of lead, cadmium, and mercury produced in the United States that enter into battery manufacturing. Their estimates for 1989 are as follows:

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Total Consumption (Metric tons)

% of Total in Batteries

Pb Cd Hg

1.28~10s 4.1 xloS 1.2 xi03

78.9 27.0 20.6

Comparable estimates for Western Europe are (2):

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Pb Cd Hg

1.58~106 6.1 x103 2.0

44 23 3

It ma be noted that a substantial fraction of the lead in spent lead-acid batteries is recyc ed and not discarded. In the United States, about 95% of the lead used in lead-acid batteries is recycled (1989) and similar figures are likely to apply to other industrialized countries, if not now, then soon. In the case of Ni/Cd batteries, a smaller fraction is recycled, but that situation is likely to improve as more recycling facilities come on stream. The battery industry has made a concerted and relatively successful effort during the past decade to eliminate mercury from their products, and, in combination with mercury recycling, these efforts may be expected to significantly reduce the addition of mercury from batteries to communal waste streams. It becomes clear that the battery contributions to the overall problem is a matter of concern. The solution of the public health problem needs to be approached as a whole by extending the required treatments to cover all the sources of these public pollutants. Since toxic materials from improperly disposed batteries and other sources may enter ecosystems that extend beyond national boundaries, the solution of the environmental roblem requires international cooperation as well as technical cooperation. d e efforts of the European Community of Nations (7,8) is a good example of what can be accomplished within an international framework, although much more needs to be done.

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3.

REGULATORY ASPECTS

Many countries worldwide are implementing legislation to re late various types of batteries, from manufacturing through disposal and/or recyc ing. It is the intent of this chapter to review the trends that are occurring worldwide in the area of regulations affecting batteries, not to get into the specifics of the re ulations. Legislation is still evolving and varies, not onl from country to country, ut within countries, i.e., between individual states and&r municipalities. A good source of information concerning the legislation passed or under consideration in various countries or states are the Proceedings of the International Seminars on Battery Waste Management, sponsored by Ansum Enterprises and BDT, Inc.

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The trend in the United States is towards increasing concern at the local overnment levels. In many instances, state and munici a1 regulations are %ecomingmore stringent than federal regulations. Recent egislation in several states prohibit the disposal of used batteries in munici a1 solid waste (MSW) and require the manufacturers of sealed lead/acid and NiyCd batteries to rovide for proper collection, transportation and processing of waste batteries. n addition, products containing these batteries must be labeled and the batteries must be easily removable by the consumer. The issue of household batteries is also being addressed. The trend is to prohibit these batteries from disposal in MSW.

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In an attempt to standardize state regulations, the Battery Council International has drafted model le islation for the states. Some states have adopted this language, while others i?ave not. At the federal level, disposal of waste batteries is regulated by several statutes (9). The Resource Conservation and Recovery Act (RCRA), enacted in 1976 as an amendment to the Solid Waste Disposal Act is intended to regulate hazardous waste from its initial generation to its final dis osal. This act defines hazardous solid waste in two general categories; listed or c aracteristic. If a solid waste is not listed on one of the Environmental Protection Agency’s (EPA) lists of hazardous wastes, the generator must determine if the waste exhibits a characteristic of a hazardous waste. Four general characteristics of hazardous waste have been identified by the EPA. These are: 1) ignitability, 2) corrosivity, 3) reactivi? and 4) extraction procedure toxicity. Once the generator determines that the so id waste is hazardous, he must meet specific regulatory requirements that govern how to manage that waste.

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All waste batteries are considered RCRA solid waste except those that are returned to the manufacturer for regeneration, reused as an ingredient without reclamation, reused as a substitute, or returned as raw material. The largest ercentage of disposed batteries are part of household waste and therefore exempt From regulation. The remaining waste batteries must be determined by the enerator whether they ualify as a characteristic hazardous waste. Penalties can %eassessed if not correct y determined.

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The Comprehensive Environmental Response Compensation and Liability Act (CERCLA) of 1980, known as the “Superfund,” as amended by the Superfund Amendments and Reauthorization Act (SARA) in 1986, regulates past and present releases of hazardous substances into the environment. This is the first major environmental law designed primarily to correct past disposal practices. It seeks to

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impose liability without regard to fault upon owners, operators, generators and transporters of hazardous substances at sites where there has been a release into the environment. This legislation enables the government to either spend funds to clean up and then seek reimbursement from the owners, operators, generators and transporters, or sue to compel liable parties to clean up a site. Other pertinent legislation includes the Clean Air Act, the Clean Water Act, and the Toxic Substances Control Act (TSCA). Within the European Community, 25 directives, regulations, and decisions have been enacted relatin to waste management (8). They are designed to encourage the prevention andfor reduction of waste by either the marketin of products designed to reduce the amount of hazardous waste durin their fulIg life cycle, or the recovery of waste by re cling, reuse or reclamation. ?$Ie cost is to be borne by the holder of the waste andror the previous holder or producer. Specific legislation relating to batteries includes the Toxic and Dangerous Waste Directive which gives priority consideration to mercury, cadmium and lead. This directive is being replaced by a Directive on Hazardous Waste which specifically includes batteries and other electrical cells. Additional metals to be covered include nickel, cobalt, silver, zinc and lithium. Thus, all commonly used batteries will be covered by this directive. The Directive on Batteries and Accumulators is focused on lead, cadmium and mercury. Its goal is to approximate the laws of the member states on the recovery and dis osal of spent batteries and accumulators containing: >25 m Hg per cell, > .O259! Cd by weight, and > .4% Pb by weight. In addition, Ni/C dg and Pb/acid batteries may only be incorporated into appliances where they can be readily removed by the consumer when spent. The batteries and appliances, where appropriate, must be labeled to indicate: separate collection, recycling (where appropriate), and heavy metal content. Other re ulations related to the safe handling and disposal of waste batteries include: birective 67/548 on the classification of dangerous substances, the Base1 convention which addresses the movement of waste, the Directive on Landfill Waste, and the Directive on Packaging and Packaging Waste. Individual countries within the European Community handle the battery waste problem differently. For example, in Switzerland all used consumer batteries are considered hazardous waste and must be collected separately from ordinary household waste. Batteries must be recycled or stored in warehouses, not landfilled. A tax is collected on all new battery purchases to help defray the cost of recycling. In Italy, spent dry batteries are considered as hazardous waste and must be collected separately. In Sweden (lo), the environmental issues relating to waste batteries are addressed in the Control of Chemicals Bill and in the Decree on Environmentally Hazardous Batteries. All used batteries containing cadmium or mercury are collected separate1 under government control. The cadmium is then recycled. Regulations are in p ace for the manufacture of nickel/cadmium cells, limiting the exposure of workers and the emission of toxic materials.

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In Japan, a number of laws and ordinances have been in effect since the late 1960's to regulate the disposal of batteries containing hazardous materials (11). Included

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are: the Environmental Pollution Control Law, the Air Pollution Control Law, the Water Pollution Control Law, and the Waste Disposal and Public Cleansin8 Law. Strict controls are placed on cadmium and certain users of Ni/Cd batteries are responsible for their proper disposal.

In Canada, several articles of legislation relate to the handling and disposal of used batteries (12). These include: the Canadian Environmental Protection Act of 1980, the Transportation of Dangerous Goods Act, and the National Waste Reduction Plan. In addition, Canada is a signatory to the Basel convention. An Environmental Choice Program is also in effect in which environmentally friendly products are so labeled. Lead/acid batteries can have the Eco-Logo if they contain >50% recycled lead and have instructions for safe disposal. To date, this has been successfully opposed by industry groups.

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The rovince of British Columbia has im osed a $5 surcharge or "green tax" on the purc ase of Pb/acid batteries to be use for a "sustainable Environmental Fund." A monitoring and tracking system has been initiated and incentives from the fund have increased the return of used batteries, especially from remote areas.

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New South Wales Australia has adopted the United States' system with some modifications. 4.

THE MANAGEMENTOF DISCARDED BATTERIES

The problems associated with discarded batteries from the highly distributed domestic sources are complicated. They involve questions of social structures, economics, technology, and re latory climates. The first problem is that of the efficient retrieval of discarded atteries. The next question that must be answered is what kinds of batteries may be allowed to enter municipal waste streams without treatment? Another question is how will the consumers know which is which? This is related to the question of the amounts of pollutants contributed by particular batteries relative to other sources of the same pollutants. It is not reasonable to consider batteries alone as a problem from the point of view of municipal solid waste (MSW) treatments when other sources contribute the same ollutants as well. Nickel/cadmium batteries are an example. Sources other than gatteries contribute significant amounts of cadmium to MSW. The elimination of nickel/cadmium batteries from MSW or the elimination of cadmium from Ni/Cd batteries will not solve problems attributed to cadmium in MSW.

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The batteries of principal concern at this time are lead-acid batteries, nickelcadmium batteries, and mercury batteries. Even though they may contribute smaller amounts of toxic pollutants to MSW than other sources, concerted efforts are and should be made to prevent pollutants from these batteries from entering the foodchain and from becoming a health hazard.

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The first step in reventing battery derived pollutants from entering the food chain is the creation o an effective collection and processing system. Since none of the toxic materials (Pb, Cd, H ) can be detoxified, in contrast to organic solvents, they must be extracted from t e discarded batteries and recycled or disposed of in secure landfills (potential future hazards?) or rendered innocuous in some other way. The recycling of battery materials will be considered in Section 5.

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Fleet operators and large scale industrial users of batteries are in a better position than the general consumer communities to collect discarded batteries. Because of the organizational structure of the former group, the establishment of collection systems within their existing organizations is relatively easy. The more difficult problem lies in the domain of domestic users, particularly the problem of the retrieval of batteries other than lead-acid batteries. The retrieval of spent automotive lead-acid batteries from domestic users, by far the most significant fraction of lead acid batteries, is relatively efficient because these batteries are sold on a trade-in basis in most cases. However, most consumer batteries are not sold in this manner. Various schemes have been tried for the collection of regular consumer batteries, They include curbside collections, public drop boxes, and various monetary incentives, but the collection efficiencies have been disappointingly low, less than 20% in Germany and Japan (13) and less than 35% in Switzerland (14). It is even more difficult to induce domestic users to presort discarded batteries. It may be argued that the collection efficiency of spent consumer batteries via public or vendor channels can be increased by suitable incentives, by penalties for failure to comply with appropriate regulations, and by sustained educational efforts. Recent efforts along these lines in Sweden have shown that considerable progress can be made (15). It must be recognized, however, that an appreciable fraction of consumer batteries is likely to end up in the general MSW regardless of any such efforts. It is necessary to supplement public collections with other methods, the most important of which are: 1. Processing of municipal solid wastes to remove the toxic materials contributed by batteries and other categories of waste.

2. Reduction in the amounts of toxic materials in batteries at the source, i.e., at the manufacturing level. The possibility of separating batteries from MSW needs to be considered within the context of MSW processing as a whole. Some data from the United States may be of interest. In 1988 the average rate of accumulation of municipal solid waste amounted to 2.8 kg per person per day (16), and it was expected to increase rather than decrease during subsequent years. (The amounts of domestic waste enerated in some other countries are (17): Japan: 1.08 Kg/person,day; France: 8.99 Kg/person,day; Germany: 0.66 Kg/person,day.) The concentration of batteries in this amount of waste is vanishingly small. Various methods have been found to be somewhat successful in extracting batteries from MSW on a limited scale, for exam le magnetic separation (18), but the large scale feasibility and the economic viabi ity of this and other methods remain to be demonstrated. Wiaux and Nguyen have discussed the sorting problem in some detail (19).

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Interestingly, in 1988 in the United States, 14% of the MSW was incinerated. The increasing rate of generation of MSW and its accumulation, combined with the decreasing availability of facilities or areas for storing such wastes in an acce table manner in most countries, suggest that incineration of MSW will be practicegto an increasing extent during the coming years. It represents a relatively effective means of reducing the volume of wastes to be stored in landfills. The exportation of solid and toxic wastes to less developed countries is an indefensible practice.

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Insofar as mercury and cadmium are concerned, and lead to a lesser extent, no matter how the incinerators are operated, a significant fraction of these materials will be volatilized during incineration and enter the ecosystem via the airborne path, unless recovered from the flues by fl ash preci itation and va or condensation, methods of questionable merit for arge scale &W operations. h e remainder of the cadmium and lead will end up in the incinerator ash and in the incinerator residues, but all the mercury may be expected to be volatilized. This means that unless the reduction of the toxic materials at the source can be racticed, the incinerator residues and flues will need to be processed to remove ead and cadmium for recycling or for safe disposal in some other manner. The most effective and also the most economical way to prevent mercury from entering the environment from batteries is to phase out the use of mercury in batteries to the fullest extent possible, an effort already instituted by the battery manufacturers, and to maintain an effective collection system for the mercury batteries still in use.

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5.

BATTERY RECYCLING

There is general agreement that toxic materials from batteries must not be allowed to enter the environment and cause harm. The question is not whether or not to render spent batteries and battery wastes innocuous, but how best to proceed to achieve that objective in the least costly manner. Three approaches may be suggested: 1. The development of non-toxic batteries. 2. The recycling of toxic materials that cannot be rendered harmless by chemical processing.

3. The storage of toxic battery residues in hazardous waste disposal sites until an acceptable recycling process can be developed. Among these alternatives, the first is the most desirable from an environmental point of view, but it may entail a significant reduction in the performance capability of batteries. Some progress has been made already by battery companies in their development of environmentally safe batteries, notably by the reduction of the mercury content of batteries and the development of a technology that may make it possible to replace the cadmium in Ni/Cd batteries with metal hydrides. It is unrealistic to think, however, that all batteries with toxic materials will disappear entirely in the foreseeable future. The batteries most likely to remain in circulation the longest are the lead-acid batteries. Interestin ly, these are the batteries that are recycled to a far greater extent than any ot er battery. Next come the nickel/cadmium batteries. Although they may begin to be replaced to some extent with the more environmentally benign nickel/metal hydride batteries during the coming years, it is doubtful that they will disappear soon, primarily because of their excellent performance capabilities. Batteries that contain mercury are already being phased out wherever feasible, and they are not expected to pose an environmental threat in the future. Probably, it may not be necessa to establish dedicated facilities for the recycling of mercury batteries. The xird alternative of storing toxic battery wastes in secure landfills or in some other secure storage facilities appears to be acceptable to many at the present time. But this is

a

145

not a solution; it is a means of postponing a solution. Eventually it will be necessary to reprocess the materials stored in hazardous landfills. It is an acceptable alternative only as an interim method of handling toxic wastes. The second alternative is the preferred solution to the potential environmental problems that may be caused by batteries that cannot be rendered non-toxic, and it is the solution most generally accepted as long as batteries are made that contain toxic materials. The operational incentives for recycling of most consumer batteries are regulatory rather than economic. Wallis and Wolsky (20) cite estimates of US $0.80/lb for the recycling cost of batteries, exclusive of any credits for recovered materials, and US $O.lO/lb for their dis osal in hazardous waste landfills. Clearly the economics favor disposal, not recyc ing. The recycling of batteries will be driven, therefore, primarily by regulatory pressures.

f

The state of the art of recycling varies for different battery systems and battery components. The processing of metallic wastes, Pb, Cd and Hg, when available as such, is straightforward and is based on well established metallurgical technologies. To the fullest extent possible, recycling should preserve metallic wastes as such to reduce the energy and other costs of reprocessing, i.e., efforts should be made to segregate the metallic wastes from materials that need to be processed chemically. In most cases, this may not be possible. Batteries comprise an intimate combination of metallic and non-metallic materials, both organic and inor anic, and they may be mixed with other trash. Given this situation and the dif erent chemical compositions of the various battery systems, the nature of the chemical processing steps required to recycle a particular waste will depend on the battery type under consideration. The recycler cannot expect to have a uniform feedstock, and, for this reason, an process under consideration should be robust, i.e., able to handle highly variable eedstocks with a consistent processing efficiency.

B

r

Considerable emphasis has been and will continue to be placed on methods of obtaining battery wastes free of other trash. In the case of lead-acid batteries this is less of a problem since the majority of lead-acid batteries are traded via automotive outlets on a trade-in basis that facilitates recycling of batteries with no admixtures. The waste admixture problem is associated primarily with general consumer batteries. To the extent that the collection of batteries as presorted waste at their points of origin can be practiced, the preferred approach, can the admixture problem be alleviated. But, however desirable it may be to separate eneral household trash from batteries, it is unrealistic to think that batteries will e available with no such admixtures, Various methods have been pro osed for the separation of batteries from other wastes at processing sites that inc ude both manual and magnetic separations and methods based on bar coding and X-ray attern recognition. However, no satisfactory method has been developed et. {he waste separation problem is likely to receive continued attention. +he unsatisfactory state of the required separation methods notwithstanding, our discussion of recyclin methods will be based on the assumption that feedstocks are available with little, i any, waste admixture.

%

P

P

Regardless of the type of batteries under consideration, attention needs to be given to their safe storage and transportation from the time they are collected until they enter actual recycling o erations. Most batteries contain aggressive electrolytes that may cause persona[ equipment, or environmental damage if permitted to

146

escape from battery wastes. The containment and control of potential spills require that adequate holding facilities be provided during storage, handling and transport; casual storage under open air conditions is not a satisfactory method. The chemical process technology for battery recycling is still in a state of flu. Established smelter operations need to be improved to meet more stringent emission standards, and some of the recycling processes for different kinds of batteries have not emerged from their developmental stages yet. The construction of some full scale plants have recently reached, or will soon reach, completion, and as operating data become available it should be possible to make more realistic assessments of the various processes based on actual data rather than on projections based on pilot plant data. The information of particular interest relate to the quality and quantity of all plant effluents on a sustained basis, plant maintenance and o erating problems lant economics, ener efficiency, as well as information on t e feedstocks. ij)nfortunately, very Byittle of that kind of information is available for full scale plants today. In the following sections, we present simplified descriptions of representative processes either employed at the resent time or proposed for the recycling of spent batteries. In the case of the fatter, many of the processing steps have passed through the pilot stage with results sufficiently encouraging to warrant advancement to the design of full scale plants.

K

5.1 Lead-Acid Batteries

Only a minute fraction, about 0.1%, of the total lead consumed by the battery industry enters into the manufacture of small consumer type lead-acid batteries, and they are likely to be discarded as part of general household waste. The recycling of batteries in that category ma be handled by processes described in Section 5.3 below. Almost all the lea consumed by the battery industry is employed in the manufacture of large prismatic automotive and industrial type batteries.

B

Discarded lead-acid batteries may be recycled by processing in conventional lead smelter operations, although the resent trend is towards recycling battery wastes in dedicated facilities operated y the battery manufacturers themselves or by independent reprocessors.

1

Thermal Processinp One of the simplest Drocesses for recovering lead from lead-acid batteries is the thermal process’developed and operated by varta (2). The main processing steps are shown schematically in Figure 1. Spent batteries are drained and fed to a blast furnace operated under reducing conditions to convert lead compounds to metallic lead and to convert sulfate to iron sulfide. The bottoms removed from the furnace is a mixture of molten lead, iron sulfide, and slag, all of which can be separated mechanically. The crude lead with its content of antimony is sent to a lead smelter for refining. The iron sulfide may be disposed of as such or reprocessed to recover iron and sulfuric acid. The off-gasses from the blast furnace contain organic vapors and some lead chloride formed by reaction between the polyvinyl chloride degradation products and lead. The off-gases are subjected to a partial quench and filtration to recover the lead chloride. The lead chloride is converted to lead carbonate and returned to the blast furnace to recover the lead. Although some of the slag may be returned to the furnace, most of it must be removed from the process to prevent an excessive accumulation of inert materials in the process

147

Ha0 Coke Ume Iron

Furno ce

Ouench

+

Fuel

.c

I

w J 'r' Filter

After Burner

PbCI.

NazCOJ

I PbCOj

Melt Seporator

Reactor

I

I

Filter

r

HzO Ash

Filter

Monual Seporator

Woste Woter

z

c FeS

c

Figure 1. Varta Process. Simplified Diagram.

Slag

Pb(Sb)

148

streams. Depending on the a plicable regulations and the quality of the operations, further reprocessing o some of the waste streams may be necessary to reduce the discharge of lead and other materials to acceptable levels.

F

Hvdrometallurgical Processin5 A-more compkated process has been developed by Engitec (21). It exploits chemical processing techniques to recycle almost all the materials in spent leadof the extensive use of acid batteries, and it produces minimal internal recyclin of process streams. in Figure 2. It egins with electrolyte and screening, flotation and hydrodynamc is smelted and refined to produce a re-usable lead grid alloy. The lead compounds in the slurry from the screening operation are digested chemically to produce a soluble lead salt that is electrolyzed to give a high purity lead. The sodium sulfate solution generated in the slurry digestor is electrolyzed to produce battery grade sulfuric acid and a sodium hydroxide solution that is recycled to the slurry digestor.

%

Although the hydrometallurgical process is more complicated than the thermal process, its principal virtue resides in the essential recovery of all of the materials in spent lead-acid batteries, including the plastic materials, and in the minimal generation of waste streams. As actual data become available on the operational characteristics and the economics of full scale plants, it will be possible to make a meaningful assessment of this process and its merits relative to other processes for the recycling of lead-acid batteries. Other processing methods and variations on the above processes have been roposed that may merit consideration. Interested readers are referred to the roceedings of the International Seminar on Battery Waste Management and the relevant journals cited at the end of the chapter for more detailed information on these and other processes.

F

5.2 Nickel-Cadmium Batteries

The recycling of Ni/Cd batteries is of more recent origin than that of lead-acid batteries. It is motivated by concern for the harm that cadmium and its compounds may do to the environment and to man and to some extent by the economic incentive to recover nickel. Although some income may be generated by the sale of recovered nickel and cadmium, it should be realized that cadmium is available in some abundance as a byproduct of zinc refining, and such income can do little more than offset the cost of recycling. The recycling of Ni/Cd batteries can be carried out by various methods, and we select a thermal and a hydrometallurgical process for discussion. As in the case of lead-acid batteries, small Ni/Cd batteries are generally discarded as part of household waste and have to be processed as discussed in Section 5.3 below. The two processes we consider rely on spent batteries as feedstock with no admixture of other wastes. Thermal Processing The recycling process developed and operated by NIFE in Sweden (22) is a pyrometallurgical process that accepts both large and small Ni/Cd batteries. A simplified diagram of the process is shown in Figure 3. Lar e batteries are dismantled manually and the separated components are fed to dif erent processing

B

Batteries

-

Shredder

HISO, Pb

Solids HBF&O) H202 Solids NaOH(H,O)

I

Filter

HzO

A'I

I

NaSO. Solution

Evopomtor

NoOH

Electrolysis

Htso4

9

Organics I t

wc

151

sections. The plastic parts are rinsed, dried, and disposed of as plastic waste or sold to plastics fabricators for reworking. The nickel electrodes and metal cases are also rinsed and collected as iron-nickel metal scrap and sold as such. The cadmium electrodes are fed to a furnace operated at about 900°C under reducing conditions to produce a cadmium condensate and off-eases that are vented to the atmosphere after filtration to collect sus ended solids. The furnace residues comprise metallic iron and nickel mixed wit slag.

K

Small Ni/Cd batteries are processed in a relatively simple manner in the NIFE rocess, the initial steps being different from those used in the case of the large gatteries. The small batteries are heated to about 400°C in a retorting furnace to rupture the cells and to pyrolyze their organic constituents. The solid residues are fed to the high tem erature furnace for processing with the cadmium feed from the lar e batteries. &e organic vapors are oxidized in an afterburner and filtered be ore being vented to the atmosphere as mostly carbon dioxide and water vapor.

B

The solid residues from the filter and from various other plant sources contain some cadmium as well as iron, nickel, and cobalt. Since they may not be discarded as waste, they are rocessed further by a sequence of selective dissolution steps, electrolysis, and ifferential precipitation to recover metallic cadmium and se arate solutions of cadmium sulfate, nickel sulfate, and cobalt sulfate that are so d to metal refiners for recycling. Depending on their compositions, the rinse and neutralizing liquors may be discarded as waste or reprocessed to recover their metal values and to reduce the plant emissions to acceptable levels.

8

P

The NIFE process has been in operation for several years, and it has been finetuned over the years to produce very low emissions and products that can be reused by the battery industry or sold to chemical a n d / o r metallurgical manufacturers. Hvdrometallureical Processing A process developed by the Department of Environmental Technology (TNO) in the Netherlands represents an interesting departure from the pyrometallurgical methods (23). It requires a feed with no admixtures of other wastes. A simplified diagram of the process is shown in Figure 4. The discarded batteries are first shredded and separated into a coarse and a fine fraction. Most of the plastic components and many of the metal parts are retained in the coarse fraction. The coarse fraction is subdivided into two fractions by magnetic means, and both subfractions are leached with hydrochloric acid to dissolve residual cadmium before being discarded as waste. The acidic cadmium extract is further enriched by usin it to wash the fines from the shredder. After filtration of the fines and the leac ing solution, the residual solids, mostly iron and nickel, are discarded. The filtrate contains dissolved cadmium, iron, and nickel. It is extracted with tributylphosphate (TBP)to remove the dissolved cadmium, and the cadmium salt is stripped from the extract by acid extraction. The TBP is recycled to the solvent extractor. The acidity of the cadmium chloride extract is adjusted to precipitate residual iron as ferric hydroxide that is collected by sedimentation and/or filtration, Metallic cadmium is recovered by eletrolysis and the stripped solution is discarded. The aqueous phase from the solvent extractor contains dissolved iron and nickel chlorides, and some cobalt chloride as well. It is oxidized at a controlled acidity t o precipitate ferric hydroxide that is removed by

fl

152

Batteries HCI Salty Waste

Plastics

Fe, Ni Waste

NaOH

TBP Solvent

NaOCl

Cd

Ni

Figure 4. TNO Process. Simplified Diagram.

153

sedimentation/filtration, and nickel with some cobalt is stri ped from the filtrate by electrolysis. The waste liquors are discarded as relatively armless waste.

R

f

The TNO process produces no exhaust gases, except for some oxy en from the electrolysers, but the various solid and liquid wastes may contain sma 1 amounts of residual cadmium. When full scale TNO plants become operational, it is likely that modifications may have to be introduced to bring all the wastes into compliance with the relevant emission regulations. It is expected that sufficient operational data will become available on a full scale TNO plant in the near future so that the relative technical and economic merits of this process can be assessed. 5.3 General Household Batteries The recycling of batteries from domestic sources presents two serious roblems. The most pressing one is that of the efficient collection and separation o batteries from other trash. An additional complication is that many batteries from both household and other sources may be permanently affixed in various devices and not easily retrievable for disposal. The cost of sorting wastes has been estimated to be about U.S. $0.50/kg (24), a significant fraction of the cost of a battery. The other serious problem is that the compositions of the feedstocks to battery recycling facilities are likely to change from time to time and from place to place. This may present a real process design problem, particularly for the less robust hydrometallurgical processes that need to be well controlled to operate consistently. The thermal processes tend to be more robust and forgiving of feedstock variations.

P

xg

Several processes have been pro osed for recycling domestic batte wastes, and we select two for discussion. ey have been chosen because of t eir otential usefulness and since they illustrate TE a variety of techniques. They are both ased on feedstocks of unsorted batteries with no admixture of other wastes. It is likely, however, that both may be able to operate reasonably well even if some such wastes are present in the feedstock. Thermal Processincr The process devegped by Sumitomo Hea Industries, Ltd., in Japan is a good example of a thermal process well suited or the recycling of spent household batteries (1). Although it was designed to handle only zinc/carbon, alkaline man anese, and zinc/mercuric oxide batteries, it can probably be adapted to han le nickel/cadmium, lead-acid, silver/zinc, zinc/air, and lithium batteries as well. A simplified diagram of the process is shown in Figure 5. Some of the operations and internal processing loops have not been shown in this diagram or reasons of simplicity.

'r

8 seconda;y

Spent household batteries with no admixture of other trash are fed to a shaft furnace operated at temperatures above 500.C where the organic battery components are decomposed and volatilized together with metallic mercury and electrolyte vapors. Practically all the mercury in the waste is volatilized in the shaft furnace. The gaseous effluents and vapors are passed through an afterburner to oxidize the organics and then passed through a scrubber and condensor to remove mercury and waste water. Part of the waste water is recycled to the scrubber and the remainder is discharged as waste after removal of sludge in a thickener. After the mercury removal from the gaseous stream, the exhaust contains mostly water

154

155

vapor and carbon dioxide. This stream is filtered to remove suspended solids, passed through an adsorber to remove residual mercury, and vented to the atmosphere. The solid residue from the shaft furnace is fed to a smelter operated under reducing conditions at about 1400°C where manganese and zinc oxides are converted to metals. The zinc is volatilized and separated from the flue gases by condensation and the zinc-free flues are recycled to the shaft furnace after scrubbing and reheating. The scrubber effluent is separated into sludge and waste water before disposal. The smelter bottoms contain an alloy of iron and manganese and slag. The two are separated and collected for sale and disposal, respectively. Although the information available on this process is somewhat limited, it appears to operate well, but it may be necessary to introduce additional rocessing steps to improve the uality of some of the waste streams and to render t e process capable of handling a 1 types of batteries likely to be present in general household wastes. No doubt such modifications and improvements will be made once sufficient experience has been gained in the operation of full scale plants.

i

4

Hvdrometallureical Processinp

An interesting-recycling process has been developed by the Recytec company in

Switzerland in cooperation with ETH in Zurich (25). It combines an initial thermal treatment wth a subsequent electrochemical process to recover separated metal values from spent household batteries. A virtue of the rocess is that it accepts unsorted mixtures of just about all types of batteries like y to be found in household wastes, and it can probably tolerate admixtures of some non-battery wastes as well. Although it is not designed to handle lead-acid batteries, it may well be capable of doing so after some process modifications.

f

A simplified diagram of the process is shown in Figure 6. Unsorted batteries are fed directly to a pyrolyzing furnace without prior shredding. The organic materials are decomposed in the furnace, the electrolyte solvents evaporated, and the mercuric compounds decomposed to yield mercury vapor. The volatilized materials are passed through a condenser to recover mercury and condensable liquids, mostly water and some organics. The condensate is fractionated by centrifugation into mercury, waste water, and an organic phase. Depending on the feedstock, the discharged mercury may also contain zinc and cadmium. The water collected from the centrifuge is passed through an aluminum cementor to extract residual mercury as an aluminum-mercury alloy, and some of the effluent from the cementor is recycled to the scrubber for the noncondensible gases from the furnace. The remainder of the effluent is sent to an evaporator to generate process steam/water and a disposable salt mixture in order to prevent an excessive salt buildup in the process. The liquid scrubber waste is recycled through the cementor. After scrubbin , the residual ases and organic vapors are oxidized in an afterburner and vente to the atmosp ere as water vapor and carbon dioxide after an adsorptive step to remove final traces of mercury.

d

a

The solids from the furnace are shredded and leached prior to magnetic separation of iron and nickel scrap from nonmagnetic solids. The leaching solution contains suspended oxides of manganese, carbon, insoluble zinc salts, and some dissolved salts. The suspended solids, mostly manganese oxides, are collected by

Batteries Fuel

:H

= Furnace

Solids

Condensate

I

-

Scrubber

Fuel

4 1 -

m

1 Condensate

After Burner

I

Condenser

Filter

#

t

NH9) Carbon

4

HZ0

Adsorber

Adsarber

4

Figure 6. Recytec Process. Simplified Diagram.

Fe, Ni Scrap

COz

157

P

decantation, dissolved in a reducing ste under acidic conditions, and electrolyzed to produce manganese dioxide anodical y and zinc and cadmium cathodicall . The bottom solids from the decanter are fed to the magnetic separator for urther processing. The nonmagnetic fraction from the magnetic separator is fractionated electrochemically by means of a unique dissolution-deposition batch process in which the relatively ure metals are collected sequentially in the order: zinc, co per, silver, nicker The residual solids, mostly carbon and graphite, are co lected by filtration.

r

f

The Recytec process is quite complicated and may need to be modified before its acceptance as a viable process for the plant scale re cling of spent batteries. When plant scale data become available it will be possi le to make the necessary assessments in terms of both plant economics and recycling efficiencies.

'41

6.

BATTERY IMPROVEMENTS

The battery manufacturing community is responding to the increasing environmental concerns and regulations with a number of changes in the manufacturing processes and ingredients in consumer batteries. Foremost is the reduction of mercury in alkaline cells to <.025%, with a continuin effort to completely eliminate mercury from this system. In the area of Ni/C batteries, much work is underway to develop a Ni/metal hydride system, to eliminate cadmium. However, it is unlikely that the Ni/Cd system will be replaced completely. In a number of applications, e.g., very hieh rate or very fast recharge, it is not clear that the Ni/metal hydride system will be able to duplicate the performance of Ni/Cd.

f

Studies have indicated that the alloys used in the Ni/metal hydride batteries pose less of an environmental risk versus the Ni/Cd or Pb/acid systems (26). However, some le islation, e+, the EC Directive on Hazardous Waste, specifically includes some o the materials used in these batteries (Ni and Co). In addition, several other heavy metals, e.g., rare earths, are used in some of the alloys. It remains to be seen how, or if, these metals will be regulated.

P

Much research is underway on rechargeable lithium batteries. These systems hold out the promise of an environmentally benign system, especially the newer "lithium ion" systems, depending on the cathode and electrolyte selected. If any of these efforts are successful, the rechargeable lithium ion battery, which utilizes a carbonaceous material as the anode, could eventually replace the Ni/Cd and Ni/metal hydride systems. Many batte manufacturers have programs in place to reduce or eliminate toxic discharges uring the manufacturin process. The elimination of halogenated solvents for degreasing and improve manufacturing processes, e.g., soldering and welding, to reduce the amount of scrap, are examples.

7

d

The lead/acid battery will remain the primary system for starting, lighting and ignition (SLI) a plications. This does not pose a serious threat to the environment, since >85% o the batteries are presently being recycled. However, the sealed Pb/acid cells used in many consumer applications will probably go the way of

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158

Ni/Cd, and be replaced by Ni/metal hydride in the near future and possibly by lithium ion in the long term. 7.

ADMINISTRATIVE STRUCTURES To succeed in minimizing hazardous waste from batteries, a detailed plan must be develo ed and put into place, both at the manufacturing and disposal/recyclin ends o the battery life cycle. A considerable effort is already taking place in bot these areas.

a

P

7.1 Manufacturing The aim of this effort is source reduction and waste minimization in factory o erations. A combination of steps are required to achieve the desired results ($7). Th ese include:

E

1) Environmental audits to identify and rioritize waste areas and to develop solutions to these problems. Also, ealth and safety audits need to be performed.

2) Source reduction at vendors who have hazardous materials in products and materials purchased. Work closely with these vendors and inspect their plants. 3) Employee involvement through training and incentives for good housekeeping and improved quality. 4) Emergency response team creation for pollution control and prevention.

5 ) Reuse and recycling of materials and packa ing. Keep materials clean and well defined so they may be reintroduced into t e production process. Specify the configuration and construction of containers that components are received in. They can then be reused, which will reduce the used container disposal volume.

fl

6) Recycle paper, cardboard, plastic and metals offsite. 7) Involvement of all departments in the plant in the source reduction and waste minimization process. 7.2 Disposal/recycling A number of steps are necessary to achieve a successful battery disposal and/or

recycling pro ram. There are several ways in which a community can approach this problem b8). 1) Separation at centralized facilities after the batteries have been discarded into the waste stream.

2) Curbside collection. 3) Voluntary centralized collection, i.e., drop-off centers.

I59 4) One day collection events.

5) Original Equipment Manufacturers (OEM) reverse distribution. 6) Focused retail programs. Since batteries make up a small fraction of the total waste stream, their collection and separation from the household waste stream is expensive. Therefore, a number of steps need to be put into place for this type of program to succeed. These include: a) Development of battery collection and reclamation programs based on the ideas listed above. b) Distribution of information to the public via newspaper, TV,radio, billboards, etc. c) Expansion of representation in legislative and environmental forums. d) Providing opportunities for diverse groups to exchange information on various options available for the safe handling, disposal and/or recycling of batteries. There are many good reasons for recycling spent batteries, however certain basic conditions must be met for a successful program (29). A sufficient quantity of spent batteries must be available, containing an adequate high concentration of recyclable substances, to become economically feasible. A simple technique must be available with justifiable energy requirements and low emissions and residues. Finally, the recovered materials must have a market. It must also be proven that battery recycling has significant ecological advantage over disposal.

8.

SOURCES OF GENERAL INFORMATION RELATED TO THE BATTERY WASTE PROBLEM The International Seminars on Battery Waste Management held annually at Deerfield Beach in Florida provide an excellent source of information on battery recyclin and related matters. The papers presented at the seminars are published in the roceedings that may be obtained from Ansum Enterprises, Inc., 1900 Coconut Road, Boca Raton, Florida 33432, U.S.A.

1

Since no journals are devoted exclusively to the disposal and recycling of batteries, readers in search of technical information not available in these Proceedings may find it useful to consult the general environmental literature and journals devoted to metsllurgical and chemical engineering. The following is a limited selection of journals that contain information on environmental technologies and roblems in general, including information on ecosystem dynamics that may be o interest to battery processors and recyclers. Many other journals are also available, especially civil engineering journals, that contain technical articles of interest to waste management engineers.

P

"Environmental Science and Technology," The American Chemical Society, Washington, DC.

160

"Journal of Environmental Systems," Baywood Publishing Co., Amityville, NY. "Journal of Environmental Engineering," American Society of Civil Engineers, New York, NY. "Journal of the Society of Environmental Engineers," Society of Environmental Engineers, London. "Pollution Abstracts," Cambridge Scientific Abstracts, Bethesda, MD. 9.

REFERENCES

Note:

ISBWM is an abbreviation for International Seminar on Battery Waste Management.

1. M. Toshio, "Sumitomo Used Dry Battery Recycling Process. Process Concept and Pilot Plant Results." Proc. 2nd ISBWM, Florida, November 1990.

2. Eurobat Bulletin. "Realized and Projected Recycling Processes for Used Batteries," June 1991. 3. N. I. Sax and R. J. Lewis, Jr., "Dangerous Properties of Industrial Materials." Van Nostrand Reinhold, New York, 1989.

4. United States Code of Federal Regulations. "Primary Drinking Water Regulations." 40 CFR 141.11

5. M. D. Royer, A. Selvakumar and R. Gaire, "Control Technologies for Defunct Lead Battery Recycling Sites." Proc. 3rd ISBWM, Florida, November 1991. 6. B. M. Barnett and S. P. Wolsky, "The Battery Waste Problem and Alternatives to Small Sealed Rechargeable Lead Acid and NiCd Batteries." Proc. 2nd ISBWM, Florida, November 1990. 7. E. Bennett, "European Community Waste Management and Its Application to Used Batteries." Proc. 2nd ISBWM, Florida, November 1990.

8. R. Eloy, "Battery Waste Management Legislation i n t h e European Communities." Proc. 3rd ISBWM, Florida, November 1991. 9. C. H. Tisdale, Jr., "Legal Issues Associated With Battery Disposal." Proc. 1st ISBWM, Florida, November 1989. 10. T. Kertesz, "Battery Collection in Swedish Municipals." Proc. 3rd ISBWM, Florida, November 1991.

11. S. Oda, "The Disposal of Ni-Cd Batteries in Landfills and the Affect of Cadmium on the Human Systems." Proc. 1st ISBWM, Florida, November 1989.

161

12. J. Grach and B. G. Terry, "Battery Recycling in Canada." Proc. 3rd ISBWM, Florida, November 1991. 13. G . B. Baum, "Model Legislation for Nickel Cadmium and Small Lead Battery Recycling." Proc. 2nd ISBWM, Florida, November 1990. 14. J. Fiala-Goldiger, M. A. Rollor and J. Hanulik, "The Status of Battery Recycling in Switzerland." Proc. 2nd ISBWM, Florida, November 1990.

15. T. Kertesz, "Battery Collection in Swedish Municipalities." Proc. 3rd ISBWM, Florida, November 1991. 16. H. Pillsbu , "Battery Recycling and Disposal in the United States." Proc. 2nd ISBWM, Frorida, November 1990. 17. J.-P. Ribes, F. Mendel, J. Zeboulon and C. Denis in L'Express Nr. 2119, February 21,1992. 18. D. E. Freeman, "Batteries in Garbage. Treatment by Mineral Dressing Techniques." Proc. 2nd ISBWM, Florida, November 1990.

19. J.-P. Wiaux and T. Nguyen, "The Sorting-Out of Spent Batteries: From Pilot Scale to Industrial Application." Proc. 3rd ISBWM, Florida, November 1991. 20. G . Wallis and S. P. Wolsky, "Options for Household Battery Waste Management." Proc. 2nd ISBWM, Florida, November 1990. 21. R. M. Reynolds, E. K. Hudson and M. Olper, "The Engitec CX Lead-Acid Battery Recovery Technology." 1st ISBWM, Florida, November 1989. 22.T. Anulf, "Recycling of NiCd Batteries - An Economic Solution to the Cadmium Dilemma." Proc. 1st ISBWM, Florida, November 1989. 23. J. van Erkel, J. J. D. van der Steen, G. van der Veen and C. L. van Deelen, "Recovery of Metals from Spent Nickel-Cadmium Batteries." Proc. 2nd ISBWM, Florida, November 1990. 24. J. David, "Cadmium Nickel Battery Treatment - An Economic Point of View."

Proc. 1st ISBWM, Florida, November 1989.

25. J. Fiala-Goldiger, J. Hanulik, Thinh Nguyen and G.C. Kin , "The RecytecTM Process for Spent Dry Cell Batteries." Proc. 1st ISBWM, lorida, November 1989.

f?

26. C. R. Knoll, S . M. Tuominen, J. R. Peterson, L. M. Metz and T. R. McQueary, "Environmental Impact Status of Select Battery Alloys in 1991." Proc. 3rd ISBWM, Florida, 1991. 27. R. L. Balfour and T. J. Anderson, "Source Reduction and Waste Minimization at Rayovac Corporation." Proc. 3rd ISBWM, Florida, 1991.

162

28. N. England, "Portable Rechargeable Battery Association's Response to Environmental Concerns." Proc. 3rd ISBWM, Florida, November 1991. 29. J. Fricke, "Recycling of Batteries - The View of the European Battery Industry." Proc. 3rd ISBWM, Florida, November 1991.

APPENDIX

Principal Recyclers of Consumer Batteries (1991)

(This list is incomplete. Please contact Dr. S. C. Levy if you wish your company to be included in future listings.) Ni/Cd

Societe Nouvelle d'Affinage des Metaux (SNAM), l a Verpilliere, France

Ni/Cd

Societe Aveyronnaise de Valorisation des Metaux (SAVAM). Viviez. France

Ni/Cd

SAB NIFE, Oskarshamn, Sweden

Ni/Cd

T N O , D e p a r t m e n t of E n v i r o n m e n t a l Technology, Netherlands Organization for Applied Scientific Research

Ni/Cd

Toho Zinc Co., Ltd., Iwaki, Japan

Ni/Cd

International Metals Reclamation Co., Ellwood City, PA, USA Mercury Refining Compan Albany, NY, USA, Viviez, prance

Ni/Cd Zn/C Alkaline cells

Recymet, SA Aclens, Switzerland

Zn/C Alkaline cells

Sumitomo Heavy Industries, Ltd. Nihama, Japan

Lithium batteries

BDT, Inc., Clarence, NY, USA

Acknowledgements

We are indebted to Dr. S. P. Wolsky for ermission to quote freely from his Proceedings of the "International Seminars on attery Waste Management" and to Dr. Brian Barnett for providing information on consumer battery recyclers.