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Development of a non-explosive mining system for underground hard rock mining
84A
ROCK BREAKAGE:HARDNESS, ABRASION & WEAR
Machine excavation 952297 Development of a non-explosive mining system for underground hard rock mining F. L. Wilke & F. Spachtholz, in: Geomechanics 93. Proc. conference, Ostrava, 1993, ed Z. Rakowski, (Balkema), 1994, pp 393-400. The common mining method in hard rock mines is drilling and blasting. Blasting vibrations, the resultant surface or mine damages and the time for smoke clearing are some reasons to substitute a mechanical - breaking or cutting mining system for heading by blasting. The application of an impact ripper is proposed because of the small tool wear and the possibility to utilize rock properties like jointing and layering. In compact hard rock the breaking efficiency will be significantly enhanced by the introduction of additional free faces to which the tool can break. To produce such free faces the practical and economical machines are diamond wire saws and circular saws. The paper describes the theoretical background and first results obtained from underground tests in a base metal mine. (Authors)
Hardness, abrasion and wear 952298 Investigation into hydraulic winning with water-jet of high pressure E. Debreczeni & I. Sumegi, in: Geomechanics 93. Proc. conference, Ostrava, 1993, ed Z. Rakowski, (Balkema), 1994, pp 349-354. For exploitation of underground mineral raw material a 'bore-hole' mining method can be used. This manner has advantages especially in such cases when the traditional mining can be realized only in addition to hazard conditions of surrounding natural dangers, following the winningoperations (e.g. water inrush, gas burst, etc.). The exploitation of mineral raw material by use of bore-hole method takes place either with mechanical winning or by means of hydraulic cutting, the transportation of won material can also be solved by the way of hydraulic transportation. The paper offers the review of research-equipment with high pressure water-jets and measured results as well as giving information about the planned bore-hole mining method.
(Authors) 952299 Water jet assisted coal and rock cutting R. J. Fowell & J. A. Martin, in: Geomechanics 93. Proc. conference, Ostrava, 1993, ed Z. Rakowski, (Balkema), 1994, pp 247-254. The application of water jet assisted 0VJA) cutting of coal and rock is reviewed and laboratory instrumented cutting tests to investigate the applicability of WJA coal cutting to reduce the amount of fine coal produced are described. (Authors) 952300 Power of pulsed liquid jets M. M. Vijay, in: Geomechanics 93. Proc. conference, Ostrava, 1993, ed Z. Rakowski, (Balkema), 1994, pp 265-274. Pulsed jets can be of various types. Experimental results indicate that they are far superior to continuous jets and are powerful for cleaning, cutting and fragmentation of various types of materials. In this paper a brief review of the literature on pulsed jets is presented. The paper includes: 1) a brief
discussion of the characteristics of pulsed jets, 2) sample experimental results and 3) recommendations for future work. (Author)
952301 The measurement of the non-setting parameters of the high pressure water jets M. Vala, in: Geomechanics 93. Proc. conference, Ostrava, 1993, ed Z. Rakowski, (Balkema), 1994, pp 333-336. The efficiency of the cutting process using high pressure water jets not only depends on the choice of the main operating parameters but also on the static and dynamic stagnation force. An original method of providing a measure of the static and dynamic stagnation force of the inner active zone of the high pressure water jets is described. The design of the measuring device is delineated. Results of initial experiments are presented and some initial conclusion are indicated in this paper. (Author)
952302 A fundamental test for parameter evaluation D. A. Summers & J. G. Blaine, in: Geomechanics 93. Proc. conference, Ostrava, 1993, ed Z. Rakowski, (Balkema), 1994, pp 321-325. The use of high pressure water as a tool to cut and mine material is becoming more common. However, there is no good model to predict the required performance of a jet system. In order to develop a standard method of evaluating projected performance, a specialized piece of equipment has been developed. A short series of traversing tests is used to identify the operational parameters for the jets to effectively cut the material. From this experimental series it is possible to define a system for effectively removing material, and to determine a production rate for a given waterjet system. The operation of the system is demonstrated using an example. (Authors)
952303 High pressure abrasive jet cutting using linear stepping movement L. Sitek, in: Geomechanica 93, Proc. conference, Ostrava, 1993, ed Z. Rakowski, (Balkema), 1994, pp 311-315. The problem with the realization of very small traverse rates occur during the development of equipment for the linear movement of a high pressure abrasive jet cutting head, because a high gear ratio is required. This problem can be solved by the use of a stepping motor, but it causes a linear stepping movement of the cutting head. This paper deals with an analysis and experimental modelling of the linear stepping movement of the cutting head and a comparison of the quality of the cut surface of linear stepping movement and continuous movement. (Author)
9523O4 A contribution to the characteristics of mineral abrasives for W J C P. Martinec, in: Geomechanics 93. Proc. conference, Ostrava, 1993, ed Z. Rakowski, (Balkema), 1994, pp 361-366. During experiments performed at the Institute of Ge~nics at the Academy of Sciences of The Czech Republic in Ostrava, a number of testing methods were used to determine the properties of abrasives destined for water jet cutting. A procedure for the analysis of mineral grains of the abrasives is proposed. The influence of the individual properties of abrasives on the efficiency of water jet cutting is described. (Author)
ROCK BREAKAGE:HARDNESS, ABRASION & WEAR
Machine excavation 952297 Development of a non-explosive mining system for underground hard rock mining F. L. Wilke & F. Spachtholz, in: Geomechanics 93. Proc. conference, Ostrava, 1993, ed Z. Rakowski, (Balkema), 1994, pp 393-400. The common mining method in hard rock mines is drilling and blasting. Blasting vibrations, the resultant surface or mine damages and the time for smoke clearing are some reasons to substitute a mechanical - breaking or cutting mining system for heading by blasting. The application of an impact ripper is proposed because of the small tool wear and the possibility to utilize rock properties like jointing and layering. In compact hard rock the breaking efficiency will be significantly enhanced by the introduction of additional free faces to which the tool can break. To produce such free faces the practical and economical machines are diamond wire saws and circular saws. The paper describes the theoretical background and first results obtained from underground tests in a base metal mine. (Authors)
Hardness, abrasion and wear 952298 Investigation into hydraulic winning with water-jet of high pressure E. Debreczeni & I. Sumegi, in: Geomechanics 93. Proc. conference, Ostrava, 1993, ed Z. Rakowski, (Balkema), 1994, pp 349-354. For exploitation of underground mineral raw material a 'bore-hole' mining method can be used. This manner has advantages especially in such cases when the traditional mining can be realized only in addition to hazard conditions of surrounding natural dangers, following the winningoperations (e.g. water inrush, gas burst, etc.). The exploitation of mineral raw material by use of bore-hole method takes place either with mechanical winning or by means of hydraulic cutting, the transportation of won material can also be solved by the way of hydraulic transportation. The paper offers the review of research-equipment with high pressure water-jets and measured results as well as giving information about the planned bore-hole mining method.
(Authors) 952299 Water jet assisted coal and rock cutting R. J. Fowell & J. A. Martin, in: Geomechanics 93. Proc. conference, Ostrava, 1993, ed Z. Rakowski, (Balkema), 1994, pp 247-254. The application of water jet assisted 0VJA) cutting of coal and rock is reviewed and laboratory instrumented cutting tests to investigate the applicability of WJA coal cutting to reduce the amount of fine coal produced are described. (Authors) 952300 Power of pulsed liquid jets M. M. Vijay, in: Geomechanics 93. Proc. conference, Ostrava, 1993, ed Z. Rakowski, (Balkema), 1994, pp 265-274. Pulsed jets can be of various types. Experimental results indicate that they are far superior to continuous jets and are powerful for cleaning, cutting and fragmentation of various types of materials. In this paper a brief review of the literature on pulsed jets is presented. The paper includes: 1) a brief
discussion of the characteristics of pulsed jets, 2) sample experimental results and 3) recommendations for future work. (Author)
952301 The measurement of the non-setting parameters of the high pressure water jets M. Vala, in: Geomechanics 93. Proc. conference, Ostrava, 1993, ed Z. Rakowski, (Balkema), 1994, pp 333-336. The efficiency of the cutting process using high pressure water jets not only depends on the choice of the main operating parameters but also on the static and dynamic stagnation force. An original method of providing a measure of the static and dynamic stagnation force of the inner active zone of the high pressure water jets is described. The design of the measuring device is delineated. Results of initial experiments are presented and some initial conclusion are indicated in this paper. (Author)
952302 A fundamental test for parameter evaluation D. A. Summers & J. G. Blaine, in: Geomechanics 93. Proc. conference, Ostrava, 1993, ed Z. Rakowski, (Balkema), 1994, pp 321-325. The use of high pressure water as a tool to cut and mine material is becoming more common. However, there is no good model to predict the required performance of a jet system. In order to develop a standard method of evaluating projected performance, a specialized piece of equipment has been developed. A short series of traversing tests is used to identify the operational parameters for the jets to effectively cut the material. From this experimental series it is possible to define a system for effectively removing material, and to determine a production rate for a given waterjet system. The operation of the system is demonstrated using an example. (Authors)
952303 High pressure abrasive jet cutting using linear stepping movement L. Sitek, in: Geomechanica 93, Proc. conference, Ostrava, 1993, ed Z. Rakowski, (Balkema), 1994, pp 311-315. The problem with the realization of very small traverse rates occur during the development of equipment for the linear movement of a high pressure abrasive jet cutting head, because a high gear ratio is required. This problem can be solved by the use of a stepping motor, but it causes a linear stepping movement of the cutting head. This paper deals with an analysis and experimental modelling of the linear stepping movement of the cutting head and a comparison of the quality of the cut surface of linear stepping movement and continuous movement. (Author)
9523O4 A contribution to the characteristics of mineral abrasives for W J C P. Martinec, in: Geomechanics 93. Proc. conference, Ostrava, 1993, ed Z. Rakowski, (Balkema), 1994, pp 361-366. During experiments performed at the Institute of Ge~nics at the Academy of Sciences of The Czech Republic in Ostrava, a number of testing methods were used to determine the properties of abrasives destined for water jet cutting. A procedure for the analysis of mineral grains of the abrasives is proposed. The influence of the individual properties of abrasives on the efficiency of water jet cutting is described. (Author)