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By T Cutts

Since 1989 Kalgoorlie Consolidated Gold Mines has managed the Kalgoorlie gold operations of joint venture partners Normandy Mining Ltd and Homestake Gold of Australia Ltd. Current production from the Fimiston Open Pit is approximately 650 000 ounces per annum. The mine incorporates a multitude of narrow shear hosted, subvertical lodes, predominantly within Golden Mile Dolerite. Traditionally KCGM has used blasthole based grade control in the Fimiston pits. A single sample is taken from vertical production blastholes, drilled on ten metre benches. This process was improved with the addition of infill drilling along blasthole rows to provide additional samples across strike. However the limitations of adequately defining subvertical mineralised structures with vertical blastholes remain. In 1997 the first of two trial areas were drilled with close spaced, inclined Reverse Circulation (RC) drilling. These tests indicated that RC based grade control had the potential to provide significant advantages. These include:improved delineation of mineralised structures, particularly across strike; reliable short-term mine schedules based on the advance data available from drilling over three benches; and the angled RC drilling is capable of providing samples of near stope and stope fill material which often remains unsampled by blasthole drills due to the safety constraints around unstable underground openings. Based on the success of this initial work RC based grade control was gradually implemented across production areas commencing September 1998. Some of the many challenges faced include:development of effective procedures and systems for the planning, logging, interpretation and modelling of the RC data; obtaining adequate drill coverage due to mine scheduling constraints and restricted access around underground openings; requirement for integrated systems to handle either blast hole or RC data; and development of effective methods to evaluate the performance of RC grade control. RC based grade control is delivering significantly improved lode definition, grade estimation and subsequent ore classification.

Jan 1, 2000

By Evans A, Jones O

Surface subsidence resulting from "total extraction" of coal in the Collie Basin first occured in 1987 when Western Collieries Ltd trialled the Wongawilli mining method. Because very little quantitative subsidence data existed for the weak, Permian sediments, a research program was set up prior to the extraction of the first panel. The objective of the study was to be able to predict subsidence characteristics and effects prior to mining future total extraction panels. Attempts at predicting subsidence began using existing subsidence models from other coal mining regions, however, as more site information became available, it became clear that it was necessary to develop a separate, she specific predictive model for the Collie Coal Basin. Analysis of extensive field monitoring data for both surface and subsurface subsidence has produced a series of empirical models which can predict the shape of surface subsidence troughs and corresponding tilts, and strains for rectangular panels and describe the sequences of ground movement from the mine roof through to the ground surface.

Jan 1, 1992

By Mutmansky J. M, Organiscak J, Qin J, Bhaskar R

The results of a two-year research study into the relationship between quartz dust levels in host material and in respirable dust in continuous mining sections are presented in this paper. The experimental design and sampling procedures for underground data collection are outlined. The sample analysis procedures for quartz determination, the analysis results and conclusions of the study are discussed.

Jan 1, 1988

By Whittaker B. N, Reddish D. J

The rockbolting method of support is employed widely in several countries in different of mines. Hard rock mines use this method extensively. Soft rock mines, such as coal mines, have employed standing supports (steel sets) as the main method, although some countries such as the U.S.A. and Australia have preferred rockbolting. There is increasing interest in extending the rockbolting method in coal mines. The application of rockbolting techniques in an industry which traditionally has not applied such techniques, has required the development of a systematic design approach. This design approach uses extensive monitoring, to asses the viability of the support system in differing conditions. Currently at a number of new and existing mine developments in the U.K., rockbolting is being successfully applied. Although, inevitably some localised geotechnical problems have been encountered and have needed to be taken into account. The effect of faulting on roadway conditions is discussed in this paper and a design approach has been applied using a numerical analysis method, namely the Finite Element Method. The results presented in the paper serve as a useful guide to roadway support designers, and in particular the role played by different bolts in a range of conditions.

Jan 1, 1992

By J Bower

The JORC Code does not specify a definition for ælevel of confidenceÆ. The common approach in the mining industry is to use a certain drill spacing or number of data samples to classify resources by the confidence categories. Another approach includes application of the quantitative geostatistical criteria for non-subjective and consistent definition of the resource categories. This approach, which has become increasingly popular in the mining industry, provides a quantitative measure of the resource estimation uncertainty. In this study, uncertainties associated with the different drilling grids at the Weipa bauxite deposit (Queensland, Australia) have been modelled using conditional simulation methodology. Criteria used at Weipa for defining resource categories are as follows: mineralisation can be classified as a Measured Resource if tonnage and grade of its volume representing three months of production can be estimated with a precision error not exceeding ¦10 per cent (at 95 per cent probability, ie two standard deviations); and mineralisation can be classified as an Indicated Resource if grade and tonnage of its volume representing annual production can be estimated with a precision error not exceeding ¦10 per cent (at 95 per cent probability). Several different grids have been created by subsampling the drill hole database. The studied variables include Al2O3, SiO2, thickness of the bauxite seam and location of the footwall contact. The variables have been modelled by sequential Gaussian simulation. Based on this study the following drill spacings have been recommended: Measured Resources û 150 m by 150 m, Indicated Resources û 300 m by 300 m.

Jan 1, 2009

The Bulli Seam, New South Wales, cenprises middle to high rank bituminous coal, generally of coking quality. It is worked over an area embracing 300 square miles.Variations in several factors are presented:The seam is somewhat. disturbed and 'dissected by various structural features. This structure, and present topography, have resulted in depths of cover from very shallow to approaching 2, 000 ft in the presently, Worked area. Wide variations of seam thickness occur. Gradations of, rank occur from-place to place. Variations in seam gas content and pride variations in seam gas composition are experienced. Variations in coal strength occur. The influences of these factors on the occurrence of stress and gas phenanena in mining exploration are considered.

Jan 1, 1963

By Fullagar P. K

In resource definition and mine development, major capital expenditures are committed on the basis of sparse information and even in production surprises such as bad ground are not uncommon. Drill holes constitute the principal source of information about the orebody and its environment and optimisation of drilling implies maximising the yield of useful information per dollar expended. Geophysical borehole logging provides new flexibility for optimising the drilling budget. Economic benefits can flow from geophysical logging at all stages of the mining cycle. The most commonly cited benefit is substitution of diamond delineation drilling with cheaper percussion or reverse circulation drilling in cases where geophysical logs can substitute for core. This approach can deliver an attractive direct saving in drilling costs (and time) if drill meterage is unchanged, or a potentially greater indirect benefit from better ore control if more holes are drilled within the original drilling budget. More ore contact intercepts per dollar can translate into lower dilution and enhanced ore recovery, thereby increasing revenue as well as reducing mining costs. Substitution of diamond drilling with percussion drilling is not always feasible. However, geophysical logging of diamond holes is often highly advantageous in its own right, both for geotechnical characterisation as well as ore delineation. Operational advantages of logging include data objectivity, speed of interpretation and reduced core handling and analysis costs. Geophysical logging assists mining engineers by providing a continuous measure of in situ rock strength, even over intervals with poor core recovery. The additional expense of geophysical logging in blast holes can be justified in terms of more accurate ore boundary delineation and rock strength evaluation. Precise ore boundary delineation permits refinement of charge placement, to minimise dilution and maximise recovery. Detailed knowledge of rock strength can enable optimisation of blast design. Rock strength can be evaluated in real-time via analysis of drill performance data recorded with measurement-while-drilling (MWD) technology. To successfully apply geophysical logging in mines, its technical, operational and economic viability must all be established. This entails verification of the existence of appropriate physical property contrasts, investigation of the best way to integrate the geophysical results with the mining method and an objective assessment of the value of the resulting mine performance benefit. Geophysical logging is already well established in many mining operations. The greatest impediments to its wider utilisation at mines are: lack of appreciation of geophysics by most mine geologists, engineers and managers; limited interpretational aids; and the necessity to re-enter completed drill holes. In this paper we endeavour to address these issues by informing mine geologists about potential applications of geophysics, by illustrating automated interpretation of geophysical logs and by highlighting the importance of emerging MWD and logging- while-drilling (LWD) technology.

Jan 1, 1997

Despite the research interest on non-cyanide gold lixiviants over the past three decades all the non-cyanide gold processes are still at the developmental stages with limited understanding on solution and pulp chemistry in some cases. This is partly associated with:the difficulties in measuring reliable equilibrium data for various gold(I/III) complexes with non-cyanide ligands; the lack of knowledge on mixed-ligand complexes; and different kinetic stabilities of gold(I) complexes with respect to disproportionation. This paper presents reliable equilibrium data for complex formation, dissolution, precipitation, hydrolysis and disproportionation reactions of gold(I/III) compounds with a range of non-cyanide ligands: S2-, HS-, S2O32-, SO32-, SCN-, SC(NH2)2, OH-, NH3, Cl-. Solubility of gold(III) compounds with non-cyanide ligands follows the order: Cl- > NH3 > OH-. In the case of gold metal the solubility order at a given temperature is MgS > Fe(III) or Cu(II) / Cl- > Cu(II)/NH3 > NaOH, but the solubility increases with increasing temperature. Rate of gold oxidation with different non-cyanide lixiviants depends on the oxidant, ligand and temperature and follows the general order of oxidants: Fe(III) or Cu(II) > X2 or OX- > O2 (X = halogen). In the case of metal ion oxidants oxygen is required to reoxidise Cu(I) or Fe(II). Some of the reported data on chloride and thiosulfate leaching of gold are presented to highlight the effect of additives and the copper, silver and sulfur contents of the starting material on the success of non-cyanide leaching processes.

Jan 1, 2004

By Johnson CR, Wilkie G

The aim of the study was to use quantitative mineralogical measurements to predict the processing characteristics of an ore. Samples were taken from a wide range of concentrators processing ores of lead, zinc, copper and nickel. QEM'SEM was used to measure the characteristics of the ore feeding the plant. Concentrate product samples, together with plant operating data were used to give concentrate grade, recovery and grind size information. It was found that the mineralogical measurements correlated well with the metallurgical parameters indicating that these techniques will be very useful for making predictions in feasibility studies and simple plant optimization.

Jan 1, 1989

By Milner E. F

Thallium is largely volatilized during sintering in the conventional sinter/blast furnace production of lead. The new direct oxygen smelting processes will force the thallium into the bullion, necessitating a means of removal to avoid contamination of the refined lead. Pilot plant testwork demonstrated that thallium was efficiently removed from lead bullion by treatment with molten zinc chloride. The spent zinc chloride salt was treated in the laboratory to recover lead sulphate, a zinc chloride solution, and a thallous chloride salt containing over 80% thallium. Cominco is installing this thallium process as part of its Trail Lead Smelter Modernization Program which will commission a QSL bath smelter in late 1989.

Jan 1, 1989

By Agrawal R. D, Kapoor M. L

Activity of FeO in the ternary system MgO-FeO-CaO in contact with metallic iron has been measured at 1000 K employing the cell.PtIFe, (Mg, Fe, Ca)OIZr02 - CaOIFe, FeOlPt. Measured data are used to study the phase stability relations in the system MgO-FeO-CaO and an isothermal section at 1000 K through this system is drawn.

Jan 1, 1987

By Windsor C. R, Thompson A, Bywater S

A new high tensile strength, steel cable, that may be grouted into boreholes has been developed for use as rode reinforcement. The manufacturing technique produces a birdcage pattern in which the cross section varies along the length of the cable. The load transfer from cement grouts to birdcage cables has been demonstrated in laboratory tests to be better than that of standard 15.2 mm diameter seven wire cables. The manufacturing process also allows for a wide range of capacities which may be specified by design engineers. The various birdcage cable configurations have been applied as rock reinforcement in a number of Australian underground and surface mines.

Jan 1, 1990

By Hanna P

Coal geologists are under pressure to minimise exploration expenditure, maximise interpretation confidence and produce the results often too soon. This pressure continues to increase as companies are forced to evaluate borderline economic deposits which are usually deeper and more hazardous, such as the Togara North and Togara South projects in Central Queensland.

Jan 1, 1998

By Wasserman A. D

Methodological approaches and in- vestigation results are considered in the paper of heatmass transfer processes when harmful impurities are scattered and remo- ved from chamber-like workings, of the air distribution in complicated ventilation sys- tems and of chemical conversion of exha- ust gases in mine atmosphere when diesel equipment is operating. The results presented in the paper are the base for creation of the automatic design, control and regulation of the venti- lation processes.

Jan 1, 1988

In 1972, metallurgical testwork on Renison ore indicated a significant proportion of low specific gravity, tin-barren material ideally suited to heavy medium separation (HMS). Further technical and financial studies provided adequate economic justification and in December 1974 the Renison HMS plant was cannissioned. Initial operations were interrupted by the imposition of tin production quotas for three months in 1976; they were also beset with difficulties particularly with regard to mechanical wear. During the first two operating years much develognent work was carried out including installation of a pyrrhotite flotation bank in the medium recovery circuit, investigations into various wear-resistant materials and the use of atanised rather than milled ferro-silicon. By 1977/78 financial year satisfactory performance had been achieved and since then the average floats rejection has been 18.8% of the total ore treated with an associated tin loss of 2.96%. Developnent has nevertheless continued during the last three years, principal modifications being the installation of larger aperture desliming screens and improvements to the overdense cyclone circuit.

Jan 1, 1978

By R Berry, A Escolme

"Predictive geometallurgical models are being developed for the Productora Cu-Au-Mo deposit based on geochemistry to reflect variability in Cu species based on Cu sequential leach data (ie oxide, transitional-oxide, transitional-sulfide, sulfide and non-recoverable Cu).Productora, located in the coastal range of northern Chile, is a magmatic-hydrothermal tourmaline breccia-hosted, structurally controlled Cu-Au-Mo deposit hosted by a thick sequence of Jurassic rhyodacitic volcanic rocks. North and north-west striking fault sets control the distribution of mineralised breccias. Alteration is widespread, complex and pervasive. Hypogene alteration assemblages range in composition from distal magnetite-amphibole, to sodic-calcic, to sodic, to phyllic, to proximal potassic. Low-temperature advanced argillic assemblages are locally juxtaposed next to proximal high-temperature K-feldspar-tourmaline assemblages. The dominant hypogene Cu phase is chalcopyrite.A simple Cu species classification scheme based on sequential leach data and S per cent was devised to account for non-recoverable Cu (ie non-sulfide Cu), which is insoluble in weak acids. Through machine learning, a proxy for this Cu species classification scheme was developed based on: depth, Ca per cent, Cu per cent, Fe per cent, K per cent, Mn ppm, S per cent and Ln(Cu/S) plus logged regolith class, thus allowing classification to be extended to areas of the deposit where no sequential leach data are available. The modelled data has been used to generate deposit-wide 3D models for Cu species classification.The validity of the proxy Cu species classification model is being tested against the results of flotation analysis. Initial results indicate that geochemical proxies can be used to successfully predict Cu species class and provide a high density of classification data.CITATION:Escolme, A, Berry, R and Hunt, J, 2016. Predicting Cu Species Classification Using Geochemistry at the Productora Cu-Au-Mo Deposit, Chile, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 113–118 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By Bingwen Z, Fengyi K

The hydraulic-stowing mining method is most effective for mining thick coal seams. It is superior to the sliced cover- caving and artificial mining method and the fully mechanized sublevel-caving mining method for the following reasons - a much higher recovery rate is achieved, there is much less surface subsidence and roof pressure, there is no hidden danger of gob fire, and much less methane emission and coal dust problems, etc.. However, its superiority is overshadowed by its backward stowing technique which makes mechanisation of mining and stowing difficult, causes bleed water interference to production and to the environment and is uneconomic because of the high cost of stowing material. These disadvantages limited its application to coal seams that are difficult and not suitable to be mined by other mining methods. The remedy is in reforming it thoroughly to permit mining of otherwise unminable seams and this paper presents the reformation.

Jan 1, 1992

By Martin C. H, Met B

INDEX OF CONTENTS:1. Introduction, Explanatory; and Reasons for Coal Cleaning.2. Principles on which Coal Cleaning is based.3. Location of Broken Hill Proprietary Co. Ltd. Plant.4. Description of Processes Selected Barvoys Bath Process; Barvoys Medium Preparation and Treatment; Static Dry Cleaning Plant.5. Detailed Description of Plant.6. Typical Results of Cleaning Operations.INTRODUCTION, EXPLANATORY, AND REASONS FOR COALCLEANING:The Institute proceedings have not previously published any matter on coal cleaning and the reasons thereof; in consequence it has been deemed advisable to allot a part of this paper to explanatory matter, prior to entering into a detailed explanation and description of the Newcastle plant.At the outset it would be as well to consider briefly the kinds of materials from which coal has originated. All coals represent some stage in the decomposition and transformation of vegetable matter laid down in prehistoric times, the vegetable matter undergoing numerous geological changes, such as submergence, overlaying by sediment, with subsequent pressure and re-elevation; these processes may...

Jan 1, 1946

Many stress measuring instruments use overcoring stress-relief principles but adopt different sensing techniques. Every technique is subject to certain limitations of rock types and conditions. To investigate the performance and reliability of the instruments in field measurement, a simple and practical approach has been developed to allow comparable laboratory results to be obtained which simulate in-situ rock and stress conditions. Four commonly used devices, the USBM deformation gauge, the CSIRO HI cell,the CSIR triaxial cell and the UNSW SI cell were thoroughly tested in the laboratory. Some conclusions have been drawn as to their suitability and reliability in different field conditions. Recommendations are provided for the choice of an appropriate technique for a given rock type and condition. A new thin-wall cell that overcomes the disadvantages of earlier devices has been developed and tested. Its laboratory performance shows that it has good prospects.

Jan 1, 1990

By Patridge A. C

Hydrocyclones have widespread use as classifiers in applications such as mine fill preparation and coal preparation. A fundamental conflict often exists between recovery of all of the valuable material and maintaining the quality of the product. This conflict is a result of a portion of the feed material passing through the cyclone, effectively without undergoing any classification. This paper describes an investigation, undertaken as an undergraduate project in mining engineering at the University of NSW (Brook, 1994), into aspects of cyclones in which supplementary water injection is used in an attempt to reduce the amount of misplaced fine material reporting to the coarse product and hence improve the overall classification efficiency. In particular, the study concentrated on the effects of different modes of water injection. Two methods of introducing wash water into the cyclone body were investigated. A series of tests were performed on a laboratory hydrocyclone having provision for radial water injection at different levels through small orifices in the wall of the conical section, and a preliminary study was made of the performance of a novel cyclone in which the conical section had walls of a permeable polyethylene, permitting a uniform introduction of wash water over the entire surface.

Jan 1, 1995