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Light-assisted oxidation of cyanide wastes
International
News
Structural glass coating process challenges move to blow-moulded plastics A newly-launched structural glass-coating process is claimed by developers Vapocure to offer the following benefits: savings in bottle weight without loss of structural strength; the ability to produce clear (flint) glass only and apply a wide range of colours and finished in the post-production phase, thus eliminating costly furnace shutdowns to permit colour changeover; the ability for manufacturers to offer, for the first time, a complete range of colours and special effects - frosted, pearlescent, stone, black, white s i l v e r - in short-run conditions at little or no extra cost to the end-user; The incorporation of light screening agents in the coating to screen out selective damaging uv wavelengths and protect degradable contents; scruff-resistance, minimising scoring and scratching and thus maximising container burst strength; minimisation of fragmentation and dispersion in the event of breakage, due to the retention properties of the coating. Special structural coatings developed can yield bottles which will not break even when dropped from 2m onto a metal plate; significant savings in segregation and recycling, as the coating will volatise on re-melt, returning to neutral flint glass; these factors allow the use of thinner and lighter walled containers, leading to reduced materials costs and a reduction in the annealing process, with its associated time and equipment. According to the company, formulations are applied by high-speed Ransburg electrostatic guns at high production rates at the "cold end" of the bottle-making operation. Since no thermal energy is involved in the process, the enormous cost of the heat sink of tonnes of glass can be completely avoided. Schweppes is now planning to undertake extensive testing of the process in conjunction with Vapocure. Vapocure: Suite 502, Spectrum Building, 220 Pacific
Light-assisted oxidation of cyanide wastes Many industrial processes including the case hardening of steel, electroplating and ore refining can result in waste waters that contain toxic concentrations of cyanide. These may be destroyed by alkaline chlorination or direct electrolytic oxidation, but the former produces considerable volumes of sludge for disposal while the latter incurs high energy costs. However, recent work by C E Byvik of the NASA's
212
Fig. A
This bottle, which has undergone the Vapocure process, was dropped l m onto a concrete floor: the Vapocure structural coating contained the glass fragments.
Highway, Crows Nest, (PO Box 84), Sydney, NSW 2065, Australia.
For further itoCormation please contact: Alastair Eperon/Isabelle Foss Ogilvy & Mather Chancery House Chancery Lane London WC2A IQU Tel: 01 831 2808
Langley Research Center and A Miles of Southern University has demonstrated another oxidation technique, which is effective in reducing cyanide concentrations to levels which are significantly below those achieved by established methods. In their solar-assisted oxidation technique, oxygencontaining air is bubbled through the waste cyanide solution, in which platinised titania powder is suspended, while it is subjected to either artificial or natural sunlight. The platinised semiconducting powders can be recovered and reused, making this an inexpensive method of treating cyanidecontaining waste water.
MATERIALS & DESIGN Vol. 7 No. 4 JULY/AUGUST 1986
News
Structural glass coating process challenges move to blow-moulded plastics A newly-launched structural glass-coating process is claimed by developers Vapocure to offer the following benefits: savings in bottle weight without loss of structural strength; the ability to produce clear (flint) glass only and apply a wide range of colours and finished in the post-production phase, thus eliminating costly furnace shutdowns to permit colour changeover; the ability for manufacturers to offer, for the first time, a complete range of colours and special effects - frosted, pearlescent, stone, black, white s i l v e r - in short-run conditions at little or no extra cost to the end-user; The incorporation of light screening agents in the coating to screen out selective damaging uv wavelengths and protect degradable contents; scruff-resistance, minimising scoring and scratching and thus maximising container burst strength; minimisation of fragmentation and dispersion in the event of breakage, due to the retention properties of the coating. Special structural coatings developed can yield bottles which will not break even when dropped from 2m onto a metal plate; significant savings in segregation and recycling, as the coating will volatise on re-melt, returning to neutral flint glass; these factors allow the use of thinner and lighter walled containers, leading to reduced materials costs and a reduction in the annealing process, with its associated time and equipment. According to the company, formulations are applied by high-speed Ransburg electrostatic guns at high production rates at the "cold end" of the bottle-making operation. Since no thermal energy is involved in the process, the enormous cost of the heat sink of tonnes of glass can be completely avoided. Schweppes is now planning to undertake extensive testing of the process in conjunction with Vapocure. Vapocure: Suite 502, Spectrum Building, 220 Pacific
Light-assisted oxidation of cyanide wastes Many industrial processes including the case hardening of steel, electroplating and ore refining can result in waste waters that contain toxic concentrations of cyanide. These may be destroyed by alkaline chlorination or direct electrolytic oxidation, but the former produces considerable volumes of sludge for disposal while the latter incurs high energy costs. However, recent work by C E Byvik of the NASA's
212
Fig. A
This bottle, which has undergone the Vapocure process, was dropped l m onto a concrete floor: the Vapocure structural coating contained the glass fragments.
Highway, Crows Nest, (PO Box 84), Sydney, NSW 2065, Australia.
For further itoCormation please contact: Alastair Eperon/Isabelle Foss Ogilvy & Mather Chancery House Chancery Lane London WC2A IQU Tel: 01 831 2808
Langley Research Center and A Miles of Southern University has demonstrated another oxidation technique, which is effective in reducing cyanide concentrations to levels which are significantly below those achieved by established methods. In their solar-assisted oxidation technique, oxygencontaining air is bubbled through the waste cyanide solution, in which platinised titania powder is suspended, while it is subjected to either artificial or natural sunlight. The platinised semiconducting powders can be recovered and reused, making this an inexpensive method of treating cyanidecontaining waste water.
MATERIALS & DESIGN Vol. 7 No. 4 JULY/AUGUST 1986