305A 915312 Opencast blasting tremls and techniques ia the Spanish mining apptry Muniz, E J Min Metal Fuel&V38, N9, Sept 1990, P188-193
of photographic and instrumental monitoring techniques and computer simulation. Improved control over drilling and blasting operations is possible. Innovative techniques such as cast blasting, controlled blasting, and air decking are now widespread.
Open pit mining and large civil works are the main consumers of explosives in Spain. Techniques adopted can be broadly divided into those for blastholes less than 15cm diameter and those for larger blastholes. Nitroglycerine based explosives are being replaced by slurry, emulsion and, in particular, ANFO and heavy ANFO explosives. Typical drilling, loading, detonation arrangements for large and small diameter blastholes are described and illustrated, together with an assessment of current trends in blasting practice for hard and soft rocks.
915317 Optimization of the surface mining technology parameters in the Arctic Anistratov, Y I Proc 1st International Symposium on Mining in tke Arctic, Falrbanks, U-19 July 1989 P47-49. Pub1 Rotterdam: A A Balkema, 1989
915313 Design of overburden casting by blasting - recent developments Chiappetta, R F; Srihara, H N; Worsey, P N J Min Metal Fuels V38. N9, Sept 1990. P194-208 Blast casting, explosive removal of overburden to the final spoil pile, is a relatively recent innovation. Developments in blast casting are discussed. Blast design parameters are critically assessed: explosive energy, pit geometry, drill selection and hole inclination, burden to spacing ratio, burden velocity, and detonation. Theoretical design, practical problems, monitoring, and computer simulation (SABREX) are considered. 915314 Planning for a large-scale blast and scope of side casting on dragline beaches in opencast mines: experieaces at Jayant opencast mine of NLC Lal, M; Agganval, M R J Min Metal Fuels V38. N9, Sept 1990. P216-219, 227 Operations at Jayant produce 13000-15000 ton/day of coal, requiring removal of 20000-25000 tons of overburden by draglines alone. Overburden blasting on the dragline benches must allow for maximum utilisation, with good fragmentation and least frequency of blasting. There are technical and environmental factors restricting the maximum size of blast. Bench blasting parameters are under constant review, considering geomechanical, engineering, and geometrical parameters. At present a 90m wide cut with a 300m length of blast is used. 915315 Role of loxite explosives in economic blast design Wadhwa, K J Min Metal Fuels V38, N9. Sept 1990. P228-232 Liquid oxygen (LOX) explosives based on cellulosic materials have been successfully used in large and small applications for varying strata conditions. The factors involved in achieving an economic blast design, and their interrelations, are discussed. Costs of drilling, blasting, crusting, and load and haul, degree of fragmentation, and rock properties must be considered. Correct selection of explosive, blast design, equipment commensurate with requirements, and personnel can result in considerable reductions in mining costs. 915316 Innovative developments ia blasting in surface mining Bhandari, S J Min Metal Fuels V38, N9, Sept 1990, P233-237, 232 Since ANFO began to replace nitroglycerine based explosives in the 195Os, there have been improvements in all aspects of open pit blasting. ANFO, heavy ANFO, slurry and watergel explosives are now available. Electrical and nonelectrical (NONEL) detonation systems have improved safety and versatility. Optimisation of blast design is now easier through use 0
Severe climatic conditions of the Arctic make surface mining operations very difficult and expensive. In order to analyse the influence of different parameters of climatic conditions on mine production processes, an economic-mathematical simulation technique is employed. The main criterion of the study is the power consumption required to break the permafrost rock. Simulation allows assessment of factors controlling the fragmentation of the frozen rocks and their influence on excavator productivity. 915318 Development of a low shock energy ammonium nitrate based explosive Wilson, M J; Moxon, NT Proc 2nd Conference on Large Open Pit Mining, Latrobe Valley, 3-6 April 1989 P39-43. Pub1 Melbourne: AusIMM. 1989 The application of ANFO in breaking weak strata often leads to inefficiencies in mining operations. These can be attributed to over-fragmentation, increased back breaks, waste of explosive energy, and increased mining costs. Research aimed at establishing techniques for producing a homogeneous low density ANFO/additive mixture with existing equipment was undertaken. It involved development of specialized laboratory mixing equipment and means of assessing performances. The results of the research work and the large scale field trials that followed are presented. 915319 Cost-efficient control of overbreak and vibrations when blasting caverns in strong rocks Hagan, T N Proc Seminar Rock Cavern-Hong Kong, Hong Kong, 8-9 December 1989 P223-234. Pub1 London: IMM, 1989 Overbreak should be controlled mostly by presplitting the walls of downhole benches and by smooth blasting those final rock surfaces created by horizontal blastholes. Where nonperimeter charges are too heavy, too close to the final surface or excessively confined, perimeter control blasting techniques will not totally prevent overbreak. Factors which need to be considered when designing and implementing blasts in order to exploit the total knowledge of the relevant geological data are outlined.
Crushing and grinding 915320 Modelling load and product distributioa ia autogenous and semi-autogeneous milk pilot plant teats Goldman, M; Barbery, G, Flament, F CIM Bull V84, N946, Feb 1991, PBO-86 Pilot plant trials were used to investigate effects of ball addition, solids concentration of the feed, specific energy consump tion, and feed size distribution in autogenous and semi-
1991 Pergamon Press plc. Reproduction