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Mine reconciliation is the practice of comparing the tonnage and grade of material processed by the mill with the tonnage and grade of ore in the reserve model of a deposit, and with the tonnage and grade in the grade control models used to de

Jan 1, 1998

By Freeman NV

The concept of an in stream analysis probe was developed at The Zinc Corporation (now Z.C. Mines) in the late 1960's and commercialised quite rapidly, by Phillips and then AMDEL, as an alternative to the established centralised systems (Courier, etc.). The developments which have taken place since that time are reviewed and current procedures and performance are described. An audit of the system, recently undertaken by AMDEL, has highlighted areas where improvements can be made. In 1988 the ISA system will become an integral part of a substantially upgraded process control system.

Jan 1, 1988

By Jackson GS

Since 1983 Cobar Mines Pty Ltd has madea concerted effort to improve the performance of its long hole open stopes, especially in the areas of dilution and fragmentation.This has resulted in modifications to stope design, drilling and blasting practice.

Jan 1, 1985

In 1939 Dr Neil George gave us the statement: Safety is a state of mind by which men are constantly made aware of the possibility of injury at all times. Is this statement still relevant? Have we been able to capture the essence of Dr GeorgeÆs statement in our current safety management systems and have we been able to capture the lessons from the past? Drawing upon 25 years of experience in the mining industry we explore what was done in the past, how this related to Dr GeorgeÆs statement and how the industry has progressed to the current safety management systems. We review the safety management system used by Roche Mining and demonstrate how it has improved safety outcomes for Roche. We then look to the future û are there new challenges? Are the current management systems equipped to cater for these new challenges and deliver continued improvement in safety outcomes? There will always be a desire to improve the industryÆs safety outcomes and so how are future generations going to achieve the improvement in safety outcomes?

Jan 1, 2007

It is commonly accepted that govern ments have a role in the financing of mineral development. The reasons for government involve- ment are examined in general and in the light of the current situation in Aust- ralia, particularly having regard to the ownership of resources. A brief introduction is given to the new Australian Government bodies, the Petroleum and Minerals Authority and the Australian Industry Development Cor- poration, designed to fill a new role in mineral development, and to the basic changes brought about by the Australian Government's decision to become involved in the future development of the country's mineral resources. It is generally accepted that governments do have a role in financing mineral development. This acceptance does not seem to be confined to Aust- ralia alone but is more a worldwide phenomenon. Mineral development has traditionally been regarded as the pre- serve of private enterprise and there- fore is presumed-to be profitable, and so it is instructive to ask why there is this special role for governments.

Jan 1, 1974

This paper outlines the thermodynamic and mass balance principles which affect the distribution of cobalt between matte and slag during the pyrometallurgical treatment of nickel - copper sulphides and considers the implications with regard to maximising the recovery of cobalt from the smelting and converting circuit.

Jan 1, 1992

By Campbell J

After eighteen months of discussions with employees and their trade unions, multiskilling was introduced at the Hellyer concentrator in early 1989, coinciding with the plant commissioning. Multiskilling was introduced with the Hellyer Skills Acquisition Program together with intensive training and performance assessment. Design innovations have helped to improve productivity. There have been some difficult times with personnel tending to return to the old and traditional ways of operating. In general, these have been overcome to ensure the success of multiskilling at Hellyer. The main factors making multiskilling effective have been continual training and assessment, and a competent team of shift supervisors. This has improved work standards towards the high level expected from a multiskilled approach without compromising safety standards.

Jan 1, 1991

By Hayward N, Sutherland D, Wilkie G

A pilot plant study has been made of the liberation characteristics of a nickel ore under different milling conditions. A series of runs were made ranging from fully autogenous grinding to semi-autogenous grinding with a ball load of 8%. The mill products were sized and assayed then analysed by QEM4SEM. This enabled a full liberation analysis to be carried out to see whether the autogenous grinding leads to improved liberation by promoting selective breakage. Though it is frequently claimed that fully autogenous grinding yields superior liberation this could not be detected in the present study.

Jan 1, 1991

By Hanes J

More than 200 bursts in coal occurred at Leichhardt Colliery prior to December 1978 during mine development in the 6 m thick Gemini seam at depths approximating 400 m. Three large bursts each displaced more than 300 tonnes of coal and stone. Two of these which occurred in continuous miner developments, are described and compared. Geological settings, mining strains including induced cleavage and roof failures associated with bursts are described. A shotfiring technique replaced mechanised mining following a major incident at the colliery. Present mining procedures, the apparent improvement in stability of workings and ongoing geotechnical monitoring programme are discussed.

Jan 1, 1980

The Split Rock low grade copper prospect was discovered in 1969 by Cyprus Mines Corporation using stream geochemistry. Cyprus "Imes carried out geochemical and geophysical investigations, geological mapping, and percussion and diamond drilling, and concluded that the grade of mineralisation was too low (0.1% copper) to be of interest. In the present study, the geology was remapped and very substantial differences from the previous observations are recorded. (lineraliced acid dykes in a 1 000 foot hole drilled by Cyprus Mines had a total inter- section of almost 300 feet with an average crade of 0.4% copper. Surrounding drill holes at distances of 500 feet did not intersect +hese dykes. This group of drill holes occupies a small part of an area about 2 km by 1 km which was affected by intense quartz sericite pyrite alteration along many fractures with an associated soil copper anomaly. It may be that the quartz sericite alteraiion with feeble copper mineralisation represents hydrothermal alteration emanating `rom a mineralised intrusion of which the dykes mentioned above are off shoots.

Jan 1, 1978

By A Yame, P J. Pollard, E Atase, J Garu, M Tangwari, D R. Hastings, R W. Smillie

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Townsville prospect is situated approximately 4 km north of the Ok Tedi copper-gold mine in Western Province, Papua New Guinea. Drilling in the 1990s delineated a resource of >1 Moz of gold within shallow, skarn breccia-hosted mineralisation associated with quartz-carbonate infill, together with pyrite, chalcopyrite, pyrrhotite, sphalerite, galena, tennantite-tetrahedrite, arsenopyrite, marcasite, and a variety of Au-, Ag- and Bi-telluride minerals. The deepest of these historical holes (TVL034) also intersected copper-gold-silver mineralisation more than 100 m below the gold-rich zone that is associated with calc-silicate skarn breccia. Although copper-gold-silver mineralisation in DDHTVL034 is associated with clinopyroxene-rich skarn, it was also noted that garnet in the skarn breccia became progressively darker in colour with depth, ranging from green at shallow levels to dark red-brown at depth. This indicated that the skarn breccia is zoned, with more proximal garnet skarn at depth possibly indicating an association with porphyry-style copper-gold mineralisation.Based on this skarn zonation model, recent drilling at the Titan prospect, located approximately 500 m south of TVL034, was targeted at potential copper-gold silver mineralisation beneath shallow skarn breccia-hosted gold mineralisation. DDHTVL 081 intersected 46 m at 6.36 g/t Au from 68 m and 80.7 m and 1.67 per cent Cu, 1.27 g/t Au and 20.32 g/t Ag from 184 m. Exploration is now attempting to define the extent of copper-gold-silver mineralisation by defining structural controls on the skarn breccia together with paragenetic and mineral zoning data.CITATION:Smillie, R W, Pollard, P J, Hastings, D R, Yame, A, Tangwari, M, Garu, J and Atase, E, 2015. Exploration of the Townsville Cu-Au-Ag skarn, western province, Papua New Guinea – preliminary observations of paragenesis and zoning, in Proceedings PACRIM 2015 Congress, pp 593–600 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Silica-Kaolin Sand Wet Sizing The Bulgarian deposits of silica-kaolin sand are localised in the eastern part of the Danube plain. After wet separation the raw material yields two products - washed kaolin (different grades) and silica sand (different grades). The water washing technology includes: disintegration; spiral classification; hydrocyclone classification and dewatering of kaolin grades; hydroclassification; sizing using drum screens and dewatering of silica sand grades. Research and development program has started to improve the silica-kaolin sand separation in processing plants. Based on the raw material and tails characterisation data and the preliminary experiments using Derrick Stacksizer screening machines a silica-kaolin sand wet sizing technology was developed. The full-scale pilot flowsheet includes the following units: Derrick Stacksizer equipped with 0.43 mm opening Derrick Urethane Panel; 500 mm Flat bottom Hydrocyclone; Derrick Stacksizer equipped with 0.150 mm opening Derrick Urethane Panel; 100 mm Hydrocyclone and Derrick Dual Motor Linear Motion Machine equipped with 0.064 mm opening Derrick Pyramid Panel. The pilot-test data clearly demonstrate that the new silica-kaolin sand wet sizing technology is suitable for Bulgarian silica-kaolin raw material. There are possibilities to increase the silica sand recovery increasing the production of silica sand grade PK 0.16 and starting the production a new grade PK 0.10.

Sep 13, 2010

By Wu H. W, Jones S. J

Australia wide, over 40 fly-in/fly-out mining operations and other forms of long distance commuting now exist, with coverage of about 5000 employees. The substantial majority of these operations are in Western Australia, with some mines also located in Queensland and the Northern Territory. In recent years new large-scale mining operations have adopted the fly-in/fly-out approach and it is important to note that no new mining towns have been constructed in Australia since the township of Roxby Downs was built in the late-1980s to service the Olympic Dam mine. An examination of fly-in/fly-out mining operations in Australia has been undertaken. A detailed survey undertaken in 1990 has been reviewed and another intensive survey undertaken to establish emerging trends. Results from both company and individual employees point of view have been analysed. A section examines the views of professional employees and the influence of fly-in/fly-out on career development. Bus-in/bus-out coal mining operations are emerging in Queensland's Bowen Basin. These operations commute their employees into the mine site for compressed working schedules while the mine employees' families are domiciled in regional cities such as Mackay. A review of the issues associated with the development of long distance commute coal mining operations in Queensland's Bowen Basin is performed and two case studies examined.

Jan 1, 1997

By Knijnikov M, Cameron D

Coal Quality management and the control of the flow of coal through complex mining preparation and transport phases of standard mining operations has assumed greater importance over recent years.

Jan 1, 1998

By Hayba DO

Metal-rich slurries discharged from excess-enthalpy geothermal wells at Kawerau (NZ) indicate that an efficient ore precipitation mechanism operates in some feedzones. In our conceptual model, which takes into account the relative permeabilities of liquid and gas phases in boiling fluids, a metal-precipitating liquid phase is effectively immobilised along boiling fronts, leading to the formation of highly concentrated ore. Chemical equilibrium and heat/mass transport modeling demonstrate the general applicability of this conceptual model to hydrothermal eruption environments.

Jan 1, 1995

The Quiruvilca district, located 80 km east of Trujillo in north central Peru (Fig. 1), has produced over eight million tons of Cu-Pb- Zn-Ag ore from approximately 60 veins since 1789. "Quiruvilca means "sacred tooth" in Quechua, the lingua franca of the Incas. The expression refers to a prominent volcanic neck exposed several kilometers northeast of the district. The district covers an area of approx- imately 24 km2. The mines occupy the eastern quarter; workings underlie 6.7 km2 with a developed vertical range of 280 m. All pres- ently operating workings are owned by Corpora- cion Minera Nor Peru S.A., a subsidiary of ASARCO Incorporated. The oldest rocks in the area are Lower Cretaceous clastic sedimentary rocks exposed 7 km to the east. Lithologies include sand- stone, siltstone, shale, coal seams, and carbonates (Cossio, 1964). These rocks were folded and affected by regional low-grade metamorphism during the early Tertiary, 40-65 m.y. (Hollister, 1977).

Jan 1, 1987

By Klinefelter G

The United States Steel Mining Co., Inc. recently experienced a major mine fire at the Cumberland Mine. This mine is located in Greene County, Pennsylvania, U.S.A. and is mining a high volatile bituminous coal seam (Pittsburgh Seam). The mine fire was success- fully controlled and extinguished without loss of life or serious injury to any miner or mine rescue personnel and finally reopened within 40 days of its inception.

Jan 1, 1988

By Boyd G. L

Stress measurement is at the core of most stability design analyses. It is demonstrated that contrary to accepted practice, it is the field measurement, and not the calculated prediction, of stress that requires most examination and review. Since it is not really possible to quantify rockmass properties, the stiffness values used in reduction of stress measurements and in subsequent design analyses (either empirical or numerical modelling) must consider an appropriate range of values.

Jan 1, 1995

The great variety of geological conditions in French coal deposits has obliged the industry to develop different thick seam mining methods. In very steep seams in a dense deposit where stowing is necessary to avoid spontaneous combustion, surface subsidence and water problems, a rising horizontal slice method is used, the coal being hard enough and the seams regular (Lorraine). In very thick and irregular steep seams where the stowing is not necessary, a sub-level horizontal slicing is used; a third method has to be used in Dauphine.

Jan 1, 1976

The desire for minimising impacts of mining activities on the environment, and in particular, water resources; is usually tempered by the costs and practicalities of implementing æbest practiceÆ measures. This paper briefly discusses the theoretical and practical options for water management for typical mines and quarries in a range of environments to assess if adverse impacts can be completely eliminated or at least be perceived as doing so. The regulatory requirements for water resources management are usually an essential part of mine planning and operations that can be a primary focus for all stakeholders. As such they can distract attention from implementing best practice in water management for the benefit of the environment and the community for altruistic reasons that have a long-term benefit for the mining industry as a whole. Cost-effective options for supply, demand and quality management of water that comply with basic regulatory requirements are readily available. Making a mine æinvisibleÆ in a practical sense, in terms of impacts on water resources would require eliminating potentially contaminated discharges, minimising demand, maximising reuse and recycling and putting back a healthy proportion of the clean water that is taken out of the natural environment for use in mine operations. This may sound simple enough and there are many well-known standard approaches that are usually applied. But which are the most effective, and who benefits? New approaches to water management are becoming more affordable and can benefit the bottom line as well as the environment, but can they make a mine ædisappearÆ? The perception of whether a mine is æinvisibleÆ in terms of its impacts on water resources is as important as the actions taken to try to achieve such an objective. The viewpoints and thresholds of perceptions of the different stakeholders are therefore relevant to how ævisibleÆ mining activities become.

Jan 1, 2006