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By Hagen G, Uhlig H

In the Federal Republic of Germany the thermal environment in underground coal mines has deteriorated progressively over the past years. The number and capacity of refrigeration plants have increased correspondingly. In recent years high capacity spray coolers have been used in addition to conventional cooling coils.

Jan 1, 1988

In the retreatment of an old tailing dump containing five per cent of lead principally as lead sulphate, the lead sulphate was floated with liquid Aerofloat reagent after sulphidising with phosphorous pentasulphide in an acid circuit. A zinc middling product was removed by flotation before recovering the lead. Concentrate products were sundried in surface dams.INTRODUCTIONDuring the period between 1917 and 1928 the Junction North Broken Hill Mine N.L. deposited several tailing dumps on its leases, which were acquired by North Broken Hill Ltd.in 1931. One of these dumps lay alongside a main road close to a residential area. The high metal prices prevailing in the post-war years (1945 onwards) provided a strong incentive for retreating this dump and transferring it to a less objectionable site.SAMPLING AND TESTINGIn 1946 a sampling and testing campaign was instituted which culminated in 1949 in a decision being made to erect a tailing retreatment plant adjacent to the dump.The dump was sampled with a 3 in. post hole auger using extension lengths of -! in. pipe for drilling to 30 ft. The dump material was fine and moist and core recovery was excellent. Hole depths ranged from 14 ft. to 30 ft., with an average dump depth of 20 ft.Individual samples were prepared from successive 9 ft.lengths of core and each sample thus obtained was, submitted for sizing and assay.The sampling showed that the dump contained approximately 380,000 tons of fine tailing assaying:

Jan 1, 1956

By Penny T. G

BHP Diamonds and their joint-venture participants DiaMet Minerals, Chuck Fipke and Stewart Blusson are currently developing Canada's first commercial diamond mine in the arctic barren lands of the Northwest Territories (NWT) of Canada. The paper reviews the early history of the project leading up to the discovery of the first kimberlite pipe in September 1991, diamond exploration techniques and the subsequent advanced exploration and development work carried out at the site. In many aspects, this exploration work represented a development project in itself. Coinciding with the advanced exploration work, the project team prepared an Environmental Impact Statement (EIS) and went through federal review of the project at the highest level. External affairs strategies regarding the federal review and aboriginal land claim issues were crucial components to the approval process. Upon approval in principle by the

Jan 1, 1997

By Anderson K

In 1991, the first horizontal raise drill hole in Australia was successfully completed by Australian Raise Drilling Pty Ltd (ARD) at the Perseverance nickel mine of Western Mining Corporation's (WMC's) Leinster Nickel Operations in Western Australia. At that time, WMC were experiencing considerable difficulties in developing the horizontal drill drives through the orebody using conventional drill and blast techniques. Following the success of the initial hole, a further two holes were drilled as part of the evaluation program. The technique has proved so successful that it has been accepted by WMC for on-going development of drill drives at Perseverance.This paper describes the program. It relates how the project evolved, the modifications that were required to the equipment used, the performance experienced during the program and the future of the method in this and other applications.

Jan 1, 1993

By Harper B

The mining industry has developed a comprehensive view of the need to have production personnel well trained in the use and maintenance of mining equipment. A strong commitment from the industry to this view has been instrumental in creating an efficient, profitable and productive industry based on modem production processes, sophisticated equipment and a multi skilled workforce. As the industry continues to develop, and the skills and knowledge needed by productive workers continues to expand, the training processes adopted by the industry will need to develop in parallel, not only making use of the latest advances in learning theories, instructional design and technology, but also using these knew ideas in more efficient ways.

Jan 1, 1998

By Canning RL, Pritchard J

The surface treatment works in the Mount Isa Mines Limited copper stream consist of a concentrator and smelter with annual capacities of 5.6 million tonnes of ore and production of 155 000 tonnes of anode copper respectively. Both plants have been sites for process optimisation in recent years, the emphasis being to achieve productivity gains in each particular plant. The continued low real world prices for copper resulted in an in-depth review of the entire copper process stream. This indicated the need for developments within both the concentrator and smelter, and changes to operating strategy to ensure that the entire treatment stream could be optimised. The paper reviews these changes.

Jan 1, 1986

By Harvey T, Kizil M, Bride J

Hydrogen sulphide (H2S) as a seam gas has occurred in several locations in the German Creek seam at Southern Colliery. This paper overviews the techniques developed to quantify the H2S content of the seam, overviews research into controlling and reducing H2S emissions from the seam, and details the procedures used to mine through the HZS zone in 702 longwall panel. Learning points from research and mining experience are reviewed for application in the next longwall block.

Jan 1, 1998

By Wilson PH

A research programme sponsored through the Australian Mineral Industries Research Association investigated two aspects of mine aerodynamics on model scale. These were aero- dynamic losses in (a) shaft/airway intersections and (b) losses created by mine cages moving in a combined haulage/ventilation shaft. The shaft/airway intersections studied included base and intermediate levels for both upcast and downcast. shafts, with one to four rectangular airways intersecting a circular shaft. Changes in intersection geometry were limited to the installation of 45¦ conical brow cutoffs of varying size and the addition of simple flow control devices. The relative air- flows between the airways and the downstream shaft were varied over a range employed in Australian mining practice. In general, experiments revealed that a small brow cutoff was significantly better than none at all, and a simple device such as a cone can reduce losses and improve flow stability at an intersection. The mine cage studies determined the effect on aerodynamic loss of cage area blockage, height/length ratio, openings in cage walls and surface roughness due to external structural members. The results show that in a combined haul- age/ventilation shaft, when the relative air

Jan 1, 1978

Burra was the largest metalliferous mine in Aus- tralia between 1845 and 1860 and employed as many as 1000 men and boys. The workforce was predominantly Cornish, Burra being the first con- centration of Cornish folk in Australia. The sur- face and underground mining operations were typically Cornish and virtually all positions of responsibility were held by Cornishmen. Beam pumping and winding engines were imported from Cornwall and housed in traditional Cornish engi- nehouses. Burra had the first significant number of beam engines in Australia: six were installed between 1849 and 1861. These engines, ranging in size from 20 inches to 80 inches in diameter, were used for pumping, hauling, and driving Cornish roll crush- ers and dressing machinery. Derelict enginehouses of the great beam engines are a striking reminder of former mining activity in Cornwall and South Australia. In South Aus- tralia about 35 enginehouses were erected between 1848 and 1887, of which eight still remain, three of them at Burra (Figure 1). These remain as a tangible link with the Industrial Revolution.

Jan 1, 1987

By Rais SA

In June, 1986, Freeport Indonesia, Inc., in conjunction with Out- okumpu USA, laboratory tested the Flash flotation concept on Primary ball mill underflow. These laboratory results indicated a possible 10% increase in precious metal recovery and 0.6% increase in copper recov- ery were available over conventional methods. By October of the same year two Outokumpu Skim Air SK-240 units were operational on one mill circuit and were achieving 5 to 10% increased recovery in precious metals with equal copper recovery at one percent higher final concentrate grade. Two more cells were purchased and installed on the remaining grinding circuit in July, 1987. As part of the installation of the Skim Air cells, an existing cluster of six 508mm Krebs cyclones were replaced by four 660mm Krebs cyclones. To reduce high circulating loads, these new cyclones were made horizontal at 45 degrees. This arrangement succeeded in reducing the mill circulat- ing load by 100% and has allowed for a 10% increase in throughput at the same grind.

Jan 1, 1988

Productivity of mines can be improved by taking fewer, but larger blasts. The initial blasts taken in starting a mining block are restricted by the low amount of void or space to fire into. Block cave mines are using a blasting technique to blast areas that have less than the normally accepted minimum void to establish drawbells for their orebody development. This technique used in block caving mines can be used to improve productivity in mining operations that utilise other mining methods. Some larger blasts have been done in mines, using open stoping methods, which have had void ratios as low as 13 per cent. This has been possible with the use of the explosive gases to transport the broken rock out of the area normally considered to be available to blasts. This trapping of the explosive gases in the broken rock has allowed rock to be moved over 30 m, horizontally, to allow for more void to be available in the blast area. This gives the necessary void ratio allowable to fire larger blasts. This paper will discuss the blasts where this technique has been used in mines to increase the tonnes fired in low void situations. It will also discuss where this type of blasting may improve the productivity of underground mines. Figure 1 shows the how explosive gases have enabled the broken rock to flow out of a draw point without the typical air blast and fly rock that would normally cause a rope suspended sign to be damaged beyond use.

Jan 1, 2008

Since 1960, the Dongchuan Copper Mining Bureau, Yunnan Province, China, has treated copper oxidised ores by sulphidisation - flotation technique only to recover copper. In order to improve the metallurgical performances and economics of flotation, extensive development work has been carried out during the past 30 years: several specific flotation flowsheets have evolved from the originally selected `stage - grinding and stage - flotation' flowsheet to suit various ores; the overall grinding size of the ores has been increased from 80 per cent - 200 mesh to 90 per cent - 200 mesh, resulting in significant increase in copper recovery; the substitution of CaS for NazS proved to be successful in sulphidisation of copper oxidised minerals, and also in avoiding the depressing effect of Na2S on copper sulphide minerals; the application of a number of activators of copper oxidised minerals, especially ethylene diamine phosphate, has considerably improved the flotation performance and decreased the consumptions of other reagents. Finally, the combined use of sodium hydroximate with butyl xanthate has been shown to be effective in enhancing the floatability of both copper oxidised and sulphide minerals.

Jan 1, 1993

In the years prior to the outbreak of war in 1939 Australia's production of copper had declined from a peak of about 80,000 tons in 1911-1915 to approximately 25,000 tons in 1939. This production met the need of the slowly growing national requirement and gave an excess for export. However, with the intensification of the war effort in 1942 due to the imminence of a Japanese invasion of this country, or at least a blockade of the sea lanes, it became necessary to expand production of armaments, and consequently the demand for copper increased beyond the capacity of the industry. Importation of copper to Australia during the period 1940-1944 was 131,000 tons.When exploration of the Mount Isa orebody was first being carried out in 1928, No. ID diamond drill disclosed the presence of some copper ore lying outside the limits of the Black Star orebody2, but it was not until 1941-1942 that the development of No. 7 level in the Black Star orebody enabled the existence of a lode of copper ore of economic grade to be established. At the request of the Commonwealth Government of the day a programme of development for copper production was undertaken whilst lead smelting was continued as before the war.A series of flotation tests on up to 1,500 tons of ore at a time, was undertaken and the concentrate so obtained was stockpiled. These tests were conducted, using one section of the lead mill, and demonstrated that a concentrate grade of 22-23% Cu with a recovery of 80-85% might be expected.These recovery figures were afterwards much improved, and 93-95%was obtained before the close of smelting in 1946.

Jan 1, 1953

By Hoffmann CF

Thermal conditions at depths of several k.i'-.r.,etres in hydrothermal systems are a major (actor controlling gold transport into the epithermal environment. Understanding of the coupling of thermal, metal and ligand (HZZ S) sources in the root zones of hydrothermal systems therefore becomes important for the application of tectonic and igneous petrochem- ical studies to regional scale precious metal exploration. The evaluation of favourable conditions in this source zone and application to explor- ation rests on a detailed knowledge of the gases, H2S, CO2 hydrocarbons and other trace components preserved in fluid inclusions. Recent developments in analytical techniques now permit examination of these components and the recognition of complex hydrocarbons in rluid inclusions from epithermal and other lydrothermal systems appears promising for ieoosit-source correlation.

Jan 1, 1987

By Ellis CG

The N.S.W. Department of Mineral Resources commissioned its first Mobile Gas Laboratory in 1973.Although originally intended for diesel exhaust analysis, it has been progress- ively made more suitable for mine air analysis. Currently there are two upgraded units in operation. These laboratories have been used at the scenes of four mine fires, two mine explosions and three recovery operations. The authors' experience jointly covers all of these incidents. In this paper they recount the role of the Mobile Laboratory in each incident - including the difficulties encountered - and trace the development of these units to their present state. Future improvements are foreshadowed, and some comments offered concerning the likely future role of these vehicles in mine Emergencies.

Jan 1, 1981

By Miller M. J, Bauer J. C

The continuous copper drossing process operated at Port Pine since 1962 has had limited copper removal capacity as determined by a maximum tolerable Cu/S ratio in feed and the level of sulphur in blast furnace bullion. Recent process development has been to overcome these limitations to meet increased copper throughput requirements. A sulphur addition system was developed and installed in August 1987. The system has capacity to increase sulphur input by over 150%, meeting the increased copper capacity requirement and also allowing independence from the upstream process for sulphur supply. Developments in process understanding have been applied within the limitations of the existing furnace design with a 10% increase in the maximum tolerable Cu/S ratio.

Jan 1, 1989

By Toguri JM

A solid electrolyte technique has been used to measure the activity of cobalt in liquid cobalt-gold alloys containing between 0.085 and 0.50 mole fraction of cobalt, and for temperatures from just above the liquidus to around 1550 K. The system exhibits positive deviation from ideality, both in the activities of cobalt and gold, and in the enthalpy and excess entropy of mixing. The results agree with previous measurements using a Knudsen cell - mass spectrometer technique, but differ from those reported for a gas equilibration method. The data have been used to calculate the activity coefficient of cobalt oxide in silica saturated iron silicate slags and to express the solubility of cobalt in such slags as a function of cobalt activity and oxygen pressure.

Jan 1, 1984

Since I first enrolled to study Mining Engineering, the idea of working with big machinery and explosives has always appealed to me. After a few courses at uni, combined with vacation work and a number of presentations at the New LeadersÆ Conferences I had attended, I began to realise that the explosives side seemed to have more appeal than the others. As I look back on the past two and a half years that I have spent with Orica Australia Pty Ltd as part of their graduate program, I would have never imagined the dynamics of explosives in mining. This I put down to the ever changing and rapid development in technology converting blasting techniques into a defined predictable science. The opportunities I have been given have delivered all the appeals from when I first started my study. As a result of my entry into a profession that uses explosives to deliver broken rock in a range of mining and construction projects, through the use of advanced blasting technology and products, my experiences have been wide and varied. These experiences have included the use of OricaÆs i-konÖ detonator technology and blast design software to allow for blasting operations to occur in a range of environmentally sensitive quarrying and construction projects throughout New Zealand, to the implementation of various Orica blast based services aimed at improving dragline dig performance and reducing coal loss thus improve overall mine sustainability in the coal mines of Central Queensland, to the advanced utilisation of Orica explosive products and technology in a number of the worlds largest copper mines in Chile. I have witnessed first hand the blasting technology available within Orica Mining Services to both deliver fundamental changes in mining results and in turn kick off my career with a bang.

Jan 1, 2009

By Hebblewhite B, Humphreys D

An experimental mining project has been carried out in the Collie Basin to demonstrate the safe operation of total extraction mining techniques in the underground mines of the basin. To achieve this, it was necessary to design and install a means of controlling or removing groundwater so that goafing of the overlying strata could be safely achieved as part of the mining operation. The site chosen for the experiment was a triangular panel adjacent to Western No 6 (WD6) underground mine, which includes the 3 to 4 m thick Wyvern Seam beneath 130 to 180 m of overburden. The test area abuts a major fault on the downdip side. The overburden and underburden sequences include several horizons of permeable sandstones which form major aquifers. Water problems have long been recognized in all underground mines in the Collie Basin, and have previously prevented the successful application of total extraction mining. Following extensive hydrological investigations, dewatering and depressurization systems were designed to dewater the immediate roof aquifers and to depressurize aquifers higher in the sequence and in the floor. This would enable stable roof conditions to develop and controlled goafing to be achieved. The roof dewatering/depressurization procedure involved a combination of in-mine vertical roof drainage holes and conventional dewatering bores constructed from the ground surface above the mining trial area. The dewatering system was installed and operated for 29 months before the commencement of mining. Mining was eventually successfully completed in two trial panels using a retreat Wongawilli extraction system using bridge conveyors and continuous miners. Water inflow into the mine workings was channelled to a constructed sump area at the lowermost corner of the panel and pumped to the surface via vertical sump bores. The dewatering and depressurization measures adopted were successful in permitting the first controlled and systematic total extraction recovery of coal from the Collie Basin. This trial mining exercise demonstrated the potential for increasing substantially the recovery of coal from the Collie Basin, where previously recovery rates of around 30 percent from underground mining were commonplace, using only bord and pillar methods.

Jan 1, 1988

FOR some years after the erection of the first chlorination plant at Mount Morgan the ore sent to the works for treatment was mined entirely from the oxidized zone; consequently, the bullion recovered at the refinery was of unusual purity, averaging about 972 in fineness, and, as no impurity in any way detrimental to the softness or toughness of the bullion was present, there was no necessity to subject it to any refining process.The charcoal from the filters was calcined to ash in small reverberatory furnaces of the usual type. The ash was mixed with suitable proportions of soda and borax to form a good liquid slag. This' mixture was then charged into salamander cruciblesand run to metal and slag in the ordinary wind furnaces-a slow and tedious proceeding in the Mount Morgan climate. The bullion, cleaned of slag, was re-melted under borax and poured into bars weighing from 350 to 400 oz.; these bars, after being dipped while hot into dilute sulphuric acid, were packed and sent to the mint. Of late years, however, the ore coming from the deeper ground of the oxidized zone became much lower in gold values, and contained variable but increasing quantities of sulphides, sulphates...

Jan 1, 1911