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By Phillips RN

Semi-confined, trachy-andesite sills which overlie the German Creek Seam, within the critical tensile strain zone, form major groundwater hazards to longwall mining at the German Creek underground mines. The water contained in these aquifers is normally neutral, but highly saline. Techniques used to detect aquifers include routine air-lift pumping in exploratory drill holes, downhole geophysical and geological logging and upstage packer testing. Hydraulic constants are calculated from pump-out and pump-in test results. Hydraulic parameters for the calculation of mine inflow rates are determined from pump-out test results because these tests appear to be more representative of aquifer drainage during goat dewatering than pump- in testing. During mining of the first longwall block at Central Colliery, caving fractures intersected overlying aquifers after the longwall had retreated 40m, and mine water inflow rate rapidly increased from less than one litre/sec to 25 litres/sec. The amount of water pumped out of the mine during first panel extraction was 140 megalitres with drawdown occurring over an area of 168 hectares. In the Southern Colliery area approximately 324 megalitres of highly saline water which is actively stored in the Aquila Sill area will be pre-drained from six well points prior to longwall mining. With effective pre-drainage from surface drill holes, maximum inflow rate into the mine during initial goafing can be reduced from 165 litres/sec to about 45 litres/sec.

Jan 1, 1988

Battle Mountain Gold Company's Paj ingo Mine is the first gold mine developed by the Company in Australia. The Mine located in northern Queensland commenced operations in September 1987. The high grade epithermal orebody is selectively mined and processed through a conventional carbon in leach/carbon in pulp (CIL/CIP) plant at a rate of 200000 tonnes per annum. In 1988 it produced 61000 oz gold and 152000 oz silver. Inadequate preoperational development of non technical management and organisational functions often leads to inefficiencies that last well into the operation. The Pajingo experience in this regard is oaTple ented by those from a number of other recently commissioned small operations. A checklist is discussed to assist any future preoperational group in focussing their attention into areas that seem to be of secondary importance at the time but often have a significant impact on overall management efficiency later.

Jan 1, 1989

By Manca PP, Rossi G, Lipari D, Knissel W, Massacci G, Licheri P, Fioravanti E, Helms W, Lai S

Mining of the massive complex sulphides orebodies of Campo Pisano and San Benedetto (Southern Sardinia, Italy), dates back to before Christ, though their exploitation with modern technology was only resumed in the middle of the last century. The increasingly adverse economic conditions and the weakness of both country rock and mineralization were concurrent in forcing the Company's management to develop suitable high-productivity stoping methods. In the framework of a project fi- nanced in part by the Commission of the European Coranunities, and carried out in cooperation with the Universities of Cagliari (Italy) and Clausthal (Germany), a cemented backfill stoping method was developed. The concrete mix preparation and placement facil- ities, study of the cement mixes and endeavaa-s to optimize the methods are described. The monitoring system for measuring stress evolution within the emplaced backfill is illustrated together with the successful replacement of part of the Portland cement

Jan 1, 1992

By Gillies A. D S, Just G. D

The advancement of computer applications in the coal industry is focusing interest on the presentation of washability data by mathematical functions.The normal method of presenting washability data is in the form of five curves, usually filled by eye or by cubic spline functions. It has been shown that coal washability can be characterised by two basic relations: the instantaneous ash vs relative density relationship and the instantaneous yield vs relative density relationship. In a new approach to the mathematical modelling of the instantaneous ash vs relative density relationship, theapplication of the algorithm to a data set from a mine in central Queensland was successful.

Jan 1, 1991

In a country richly endowed in mineral wealth, Climax Arintco Mining Corporation's ICAMC) Dinkidi porphyry Au-Cu deposit in Nueva Vizcaya, Philippines, represents the most significant mineral discovery in this country in recent times. The deposit is located within a belt of young intrusive and volcanic rocks in the Sierra Madre mountain chain of north Luzon, a region previously unassociated with porphyry -style mineralisation.Since 1989, drilling of the Dinkidi deposit has outlined a resource of 124 million tonnes of 1.0 g/t gold and 0.4 per cent copper. Regional exploration throughout CAMC's 37 000 hectare FTAA has identified a further 16 potential porphyry-related deposits.

Jan 1, 1997

By M D. Goodz, Wright R. F

This paper highlights the importance of accurate observational technical reports compiled by Mining Geologists and Engineers. Before uncovering the original reports in July 1992, all previous investigations discounted returning to old mining areas on the belief that all operations were suspended because they were 'unpayable'. However, the detail of the original reports removed any doubt of the economic value of retrieving remnant ore.The important feature was that the description of 'unpayable' by GMA could be equated to 11.6 - 35 g/t over the history of the mine. On the basis of these reports the Morning Star mine has been re-opened.

Jan 1, 1993

By Woodcock J. T, Sparrow G. J

Activated carbon particles obtained from a number of Australian CIP operations were examined with an optical and a scanning electron micro- scope and an electron microprobe. External surfaces, and polished sec- tions through individual particles, were examined with special reference to materials on the surface and to calcium and gold distributions. Photographs are presented of surface contamination of the particles by salts precipitated from the pulp such as calcium carbonate (calcite), calcium sulphate (gypsum), and a magnesium salt; ore minerals such as quartz, hematite, pyrite, arsenopyrite, pentlandite, and various alumino- silicates; and other substances such as grinding media and a fungus. Calcite was very abundant but the other materials were less common. Contamination in the interior of carbon particles was almost exclu- sively calcium carbonate, and extensive contamination extended to the centre of some particles. A possible mechanism for the formation of cal- cium carbonate inside the carbon particles is noted. Gold X-ray dot maps of sections through carbon particles indicated that gold was distributed throughout coconut shell carbons and that although gold was more concentrated near the outer surfaces of extruded peat carbon particles, it was also present to depths of at least 500 ¦m. The gold distribution throughout the carbon particles was similar to that rf alrit~

Jan 1, 1988

In South African gold mines, the types of material requiring transportation to the stoping areas include timber packs, explosives, hydraulic rock props, scrapers, scraper winches, pipes, pumps and backfill material (in areas where backfill is being used). Currently timber packs are broken down to their basic components (log and brick) and are transported into the stope by means of either monowinches or a combination of monowinch and scraper winch. Other materials, such as explosives, hydraulic rock props, scrapers, scraper winches, pipes, pumps and backfill material must be transported by other means, usually by hand or, in the case of heavier items, by chain blocks. With the drive to increase stope advance rates and the rise in the number of miners with HIV/AIDS, there is a need in the South African gold mining industry for an improved material handling system. To meet future requirements, material handling systems should assist miners to transport materials quickly and efficiently. Furthermore, it must be financially viable and economically competitive with current material handling systems. This paper looks at the in-stope material handling efficiency of current monowinch systems and provides solutions to improve efficiency. In addition, the use of in-stope monorails are reviewed and the possible scenarios that will substantiate the use of monorail systems are discussed.

Jan 1, 2003

Segregation studies in ternary systems of glass ballotini, iron ore and coke particles (with size range of 1-8 mm in each) in filling and emptying a laboratory size Paul Wurth hopper are described. In-bin segregation is shown to be a function of the position in the hopper, the nature of the material and the feed composition. The in-bin results are correlated by the equation C = C0k, where C and C0 are the size compositions (wt per cent) in the hopper and feed respectively, and k is an experimentally obtained segregation constant. The results of now pallern measurements show that material discharges from the hopper according to the sequence; core now - wall now - scaffold now, where the latter represents stagnant material at the hopper wall that discharges last. Size segregation in the discharge stream from the hopper is shown to be a function of in-bin segregation and hopper now pallern. A method of predicting discharge segregation from these two sets of data is suggested. The results of the model studies are also compared with industrial data and these show satisfactory agreement. Discussion of the hitherto ignored effect of size segregation on hopper now rates, stoppages and other operating problems is also included.

Jan 1, 1985

A novel fracture-plane control blasting technique with particular application in wall-control blasts in mines employing medium to large diameter boreholes is described. It consists of a string of nested holes, each nest consisting of a large diameter charge-hole flanked on either side by a small diameter satellite hole. Each nest is shown to be an analog of a pressurized hole with diametral notches along its length. This 'equivalent-notched' hole concept for generating controlled fractures along preferred directions has been successfully investigated in the laboratory and in the field. The technique has been used to generate controlled fractures on a quarry bench in highly jointed limestone. The resulting blasts with a 250 mm diameter central charge-hole and 50-75 mm satellite holes show that two nests of such holes almost 5 m apart could be joined by a single co-linear fracture. The design range of diameter ratio between charge-hole and satellite hole is 3 to 6 and spacing is 3 to 5 charge-hole radii. With careful matching of explosives and decoupling, and combination of diameter ratio and spacing, it would be possible to connect two nests of such holes more than 20 charge diameters apart by a single controlled fracture plane. The relative merits of the technique against existing wall-control blasts are discussed, and guidelines for practical fracture-plane control blast designs are discussed.

Jan 1, 1990

By J Zanganeh, M Ajrash, B Moghtaderi

Application of thermal oxidation is considered a promising technique in reducing fugitive methane gas from ventilation air methane (VAM). A typical thermal oxidiser operates with diluted methane and converts it to less potent greenhouse gases. However, having a thermal oxidiser in the vicinity of the coalmine exhaust shaft is a major safety concern as its high operation temperature increases the likelihood of accidental fire and explosion. The aim of this study is to investigate the application and effectiveness of side venting technique in reduction of deflagration consequences caused by methane gas. To address this importance a series of experiments were conducted on a detonation tube designed and fabricated as part of larger scale VAM Abatement safety project. The experimental work was carried out into two stages: examine the flame and explosion properties in a large-scale detonation tube to get reliable data; and then design and employ a venting system into the detonation tube to verify the effectiveness and performance of the venting against the flame and explosion.Results corresponding to this study show that the side vent duct with venting coefficient magnitude of 37 had a significant influence on methane flame deflagration and the explosion characteristics. The maximum pressure rise at the detonation tube reduced approximately 20 per cent to 32 per cent by applying the side venting duct. Also, the data shows that the venting damped the pressure oscillation after the flame deflagration which eventually reduced the system instability. Finally, by applying the venting technique the expected level of damage due to the dynamic pressure reduced to the level of limited building damage.CITATION:Ajrash, M, Zanganeh, J and Moghtaderi, B, 2017. Application of side venting technique in mitigation of methane – air explosion and flame deflagration in ventilation air methane, in Proceedings Australian Mine Vent Conference 2017, pp 153–258 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By Smith CB, Boxer GL

The Argyle diamond deposits in the East Kimberley were found as a result of a long term exploration programme, begun in 1972 by the Kalumburu Joint Venture (KJV), to search for diamonds on the Kimberley craton. When CRA Exploration Pty. Limited joined the KJV in 1976, it was re-named the Ashton Joint Venture (AJV). The Kimberley craton was considered prospective by analogy with structural settings of diamondiferous kimberlites in Africa. Diamonds were found during regional drainage sampling in Smoke Creek in late 1979, which led directly to the discovery of the rich Argyle lamproite diatreme (AK1) and associated alluvial deposits of Smoke and Limestone Creeks. The diatreme intruded into quartzites, sandstones and shales of Adelaidean age, and consists predominantly of lapilli ash tuff, with minor coarse and fine ash tuffs, 'non-sandy tuff' and olivine lamproite dykes. Erosion of the diatreme has produced the alluvial deposits of Smoke Creek and Limestone Creek to the north and east. Argyle diamonds are of predominately industrial quality, and the typical diamond is a brown, irregularly shaped, frosted, heavily resorbed form with abundant graphite inclusions, well developed etch channels and prominent hexagonal surface depressions. The pre-feasibility evaluation of AK1 comprised diamond drilling, surface and underground sampling, metallurgical sampling, marketing studies and ore reserve estimation. The proven AK1 ore reserve is 61Mtonne at 6.8ct/tonne. Evaluation of the alluvial deposits gave results of Upper Smoke Creek, 580 000 tonne at 4.6ct/tonne and Limestone Creek, 1.7Mtonne at 3.5ct/tonne. Commercial production from the two alluvial deposits began in 1983 with production for the year reaching 6.2 Mct. Mining of the alluvial deposits at three to five Mct/year is proposed to continue until the start of mining of the AK1 deposit in late 1985 or early 1986 at which time a new processing plant and associated infra- structure will have been constructed adjacent to the AKl deposit in the Limestone Creek area. Production is planned at three Mtonne/year, producing 25Mct/year, which will make Western Australia the largest producer of natural diamond (by weight) in the world.

Jan 1, 1984

By Durucan S

The southern Attiki peninsula is a very interesting area from an environmental point of view. The port and the city of Lavrio is situated at the east coast of the peninsula with about 10 000 inhabitants and there are also a few villages in the vicinity. The south-eastern part of the peninsula hosts the famous Lavrio mines which exploited the silver bearing orebodies of the area for more than 25 centuries. As a result, soils around the city of Lavrio are polluted with high heavy metal loads. The area is also of archaeological interest, as there are well preserved remnants of ancient mining and processing plants and archaeological sites. Soil samples collected from an area of approximately 120 km2 around Lavrio were analysed for their metal contents and the spatial distribution of the concentrations of ten selected elements were estimated from these data sets. The spatial data analysis and transformation capabilities of Geographic Information Systems, combined with extensive mining and geological data, helped the authors to identify the extent and causes of metal pollution around Lavrio.

Jan 1, 1995

The Porphyry Gold Mine (150km NE of Kalgoorlie) was reopened in November 1983 with production commencing in April 1984. Original reserves quoted for the open pit were 822000 tonnes at 5.2 g/t Au based on wide spaced diamond drill holes. Close spaced grade control drilling has revealed some loss of tonnage and a significantly lower grade. In the area of the pit mined to 30 June 1985 this grade control reserve estimate contained 67% of the gold in the original ore reserve with the grade being 19% lower. It is anticipated that the final grade control reserve estimate will contain around 80-85% of the gold contained in the original reserve. There has been close agreement between the Mill Head grade (4.19 g/t Au) and the grade control predicted grade (4.2 g/t Au) confirming that dilution is not a major problem. After initial poor agreement (attributed to "lock-up" in the circuit) the bullion calculated head grade steadied out at 93% of the grade control prediction. This difference is considered to represent the geostatistical bias in the drill hole/crushed rock sampling. Gold recovery has been in the range 93-95% (compared with bullion calculated grade). The net result is that the recovered grade of ore mined to 30 June 1985 is 70% of the original ore reserve grade.

Jan 1, 1986

By D S. Clarke, K B. Sporli

Structure is an important control in the localisation of gold mineralisation in epithermal systems. There has been, however, only limited investigation of the structural elements involved; such a study is currently directed at the gold deposits of the Coromandel Volcanic Zone (CVZ). Here, mineralised veining and brecciation ranges up to tens of metres in thickness. Dips of veins are mostly steep, but not vertical, and there is a significant number of low angle veins. The structural control of epithermal deposits may be considered on four scales. At the mega-tectonic scale, pre-volcanism fault patterns mostly relate to separation of the New Zealand micro-continent from Gondwana. The major structural controls on mineralisation at this scale, however, are associated with the volcanic arc processes responsible for the CVZ. Post-mineralisation faulting are linked to the Hauraki Rift and the Colville Ridge-Havre Trough system. Regional scale faults controlling the distribution of gold deposits are the product of these tectonic events; much of the faulting may relate to rifting and calderas, but further work is required to demonstrate this. Detailed study is also needed on vein systems at the prospect scale to validate models of brittle deformation responsible for such systems. Evidence that a variety of structural mechanisms dominated in different deposits is found at the vein scale, with Coromandel gold deposits being classified according to their different styles of vein-fill texture.

Jan 1, 1990

By Glenn R. J

Treatment processes are outlined for the recovery of rutile and zircon from the heavy mineral-bearing sands on the east coast of Australia. With the exhaustion of the higher grade deposits and the imposition of more rigid specifications for the finished products, strict metallurgical control has become necessary.A description is given of the methods used by The Titanium Alloy Manufacturing Co. Pty. Limited to control the operation of suction dredging, of wet concentration using fans and spirals, and of dry separation using high tension and electromagnetic processes. By applying these methods a plant designed for an output of 15,000 tons of rutile per year has been tuned to produce over 20,000 tons of rutile and a corresponding amount of zircon.Details are given of (a) the method of drilling to determine the extent and grade of the ore bodies, (b) a simple electrically-timed pneumatic automatic sampler, and (c) the methods developed for the physical estimation of quartz, rutile, zircon, ilmenite and "others" in the products of plant operation.The method used for calculating the metallurgical balance and the forms used for the reporting of production results are presented.Examples are given which show the value of this detailed production and metallurgical control of plant operation.INTRODUCTIONThe organization which is now known as "The Titanium Alloy Manufacturing Co. Pty. Limited" (T.A.M.Co.)-a subsidiary of National Lead Company-commenced operating at Yamba, N.S.W., in 1935. A mixed natural concentrate was at first simply dried and bagged and later was upgraded by the removal of silica and the lighter heavy minerals on shaking tables and, after air-drying, was bagged for export. At that time zircon was the most wanted constituent.

Jan 1, 1960

By Peng S. S

Measurement of pressure distribution under the base plate of the Hemscheidt 2-leg 800-ton shield was performed underground for two shifts using 12 pressure cells installed in two rows, one each under each split base plate. Pressure distribution was uneven depending on contact condition. In general the highest base pressure occurred at 1/3 of the base plate contact length from the rear edge. The resultant was near vertical, and the pressure under the tail side split base plate was always higher than the head side. For comparison, pressure distribution on the canopy and under the base plate was also measured under controlled conditions at the USBM's Mine Simulator Testing Facilities in Pittsburgh, PA. A total of 45 tests were conducted under several simulated contact conditions. The results showed that the actual contact area is highly dependent on the compliance of the immediate roof and floor due to the sloped canopy tip and a base lifting device under the base tip. The loading distribution tends to change in magnitude and profile as the leg pressure increases. The base lifting device exaggerates the high toe loading on the base plate characteristics of this type of shield support.

Jan 1, 1992

The occurrence of metallic minerals in Australia to the time of the proclamation of South Australia as a Colony in 1836 was unknown. It is, therefore, perhaps, surprising that British settlers arriving in the Coromandel included among their number a German scientist Johannes Menge who had been appointed by the South Australian Company to the post of Mine and Quarry Agent and Geologist on 1 July 1836. His instructions were to `explore the natural productions of the Colony above and below ground and to superintend the working of quarries of stone and slate, the boring for water, metal, lead, coal and other mines at a salary of ú150 per annum for one year and for as much longer as the Company require your services not however exceeding five years'. In the event, he was to have little influence on those matter.

Jan 1, 1993

By J Krawcz, S Wasilewski, W Mironowicz

Barometric pressure and its variation in deep underground workings have a considerable effect on ventilation conditions. Pressure changes which create transient states of air flow and air parameters in workings are especially significant. Experiments have shown that pressure changes have a remarkable effect on air parameters at mine workings and hence, attempts to evaluate the scale of this phenomenon are of value. Continuous monitoring of the barometric pressure on the surface of mines allows for the detection of changes in pressure which undoubtedly influence alternations of pressure in the underground areas of mines. Very important factors are the internal disturbances of pressure within a mine ventilation system due to variable conditions of fan operation and the operation of a winding machine where a mine cage moving in a shaft causes piston like disturbances. Local transient disturbances caused by temporary opening/closing of air stoppings due to personnel or underground transport traffic are of importance. The results of over two years of observations of barometric pressure and its influence on pressure variation in underground mine workings are presented in this paper. The observations were possible through the installation of pressure sensors at selected points of the downcast shaft in a mine. Of interest are the observations of the transient states of pressure and other air parameters caused by emergency fan stoppage, movement of a mine cage and changes due to the opening of air stoppings. Data acquired during experiments of opening and closing air stoppings were used for the validation of a flow model in a long working.

Jan 1, 2005

Pongkor Gold Mines is one of seven units of production owned by PT Aneka Tambang (State owned mining company). The mine is located in the western part of Java Island, Indonesia. It is in the Bogor District and approximately 110 kilometres to the south of capital Jakarta. It is located in very steep hilly terrain intersected by many river valleys and the mine site is approximately 500 metres above mean sea level (see Figures 1 and 2 - Mine location map and picture)

Jan 1, 1997