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By A Lim

"As Abel Mine continues to expand and increase production, the requirements of the ventilationsystem have also increased. This paper will outline the stages undertaken to increase the AbelMine ventilation system from an operating position of 110 m3/s and 500 Pa to the current operating position of 220 m3/s and 1.6 kPa and outline steps to be taken to ensure all future requirements will be able to be ventilated."

Jun 1, 2012

Successful management is ultimately measured by return on shareholders' funds. This is the inescapable and inexorable discipline that ultimately rules every investment. Shareholders today are predominantly, and increasingly, the superannuation funds and insurance funds of almost all of us. We have already reached the situation in Australian investment history in which the best interests of employees can be very directly identified with the best interests of the owners of the capital invested.

Jan 1, 1992

This paper provides a financial perspective to the valuation of Australian resource companies and projects. Valuation exercises need, however, to be seen in the broader context of a thorough business appraisal, one that incorporates all disciplines employed in the resources industry. Fine tuning a discount rate or determining a particular capital structure is likely to be less important to valuation than an adequate understanding of industry dynamics and a company's likely performance in future years.

Jan 1, 1989

By Corbett G, Iwai N

The Japanese gold mining industry has a long and productive history and is presently undergoing a period of revitalisation encouraged by the Hishikari discovery. Deposits exhibiting the characteristics of epithermal mineralisation are very widely distributed throughout the island chain and an encouraging number of these are large, seven containing gold in excess of one million ounces. All the important deposits are quartz vein type and contain extremely high grade, or "bonanza". Zones.

Jan 1, 1990

By Radenkovic C, Ivkovic S, Minic I

The model, already tested and applied, enables a highly efficaceous solution of the problem of issuing instructions for interested services on the basis of known contents of in- dividual stages of mine mechanization repair and known time intervals between repairs for specific machines and total mechanization. Application of the model provides work orders for all types of repairs for specific machines or systems, and orders for the commercial department regarding spare parts Supply.

Jan 1, 1977

The restructuring of the minerals industry has created new challenges for the design and delivery of professional development, and difficult decisions for potential participants. New technologies offer some new methods of delivery, but fall short in providing all of the benefits of face-to-face participation. This paper is intended to be a catalyst for discussion of the issues involved in delivery and participation in cost-effective, relevant and timely professional development.

Jan 1, 2000

Evaluation of tyre chains has been taking place at King Island Scheelite for several years. Results indicate that tyre life has been greatly improved in all cases. Good cost sav- ings are resulting on small loaders. The worth of chains is difficult to prove on larger loaders under the conditions at King Island Scheelite. However, the dramatic decrease in the number of punctures has convinced the Company that chains are worthwhile on some larger loaders.

Jan 1, 1977

By Braes J. R, Neale J. R

The New Broken Hill Consolidated Limited (NBHC) mine currently produces 1.42 million tonnes of silver, lead and zinc ore annually. All of this ore is treated by the NBHC milling ccx[plex. This paper describes the crushing, grinding, flotation and filtration circuits used in the treatment of this ore and lists the major items of equignent used in these circuits. Metallurgical results, manning levels and consumption rates of reagents and grinding media are shown.

Jan 1, 1983

By S Basu, P M. Midhun

Electro-Slag Remelting (ESR) is a process capable of producing ingots with much lower centre-line segregation and better internal soundness than conventional ingot casting processes, as well as lower inclusion and sulfur concentrations. This process is commonly used for alloyed steels intended for critical applications like components of marine turbines, supercritical powerplants and rocket motor casings. It involves melting a metal electrode using electrical resistive heating in a slag pool and re-solidification of the resulting metal droplets beneath the slag layer, forming an ingot. Conventional ESR fluxes consist primarily of CaF2, Al2O3 and CaO, along with minor concentrations of SiO2, MgO etc. The emission of fluoride vapour from the molten slag causes several environmental and health problems, triggering a need to develop and reduce the fluoride content in the ESR flux. The present study aims to develop low-CaF2 alternatives to commercial ESR fluxes without compromising on productivity and the surface quality of the refined ingot. Thus, the modification in chemical composition needs to satisfy properties like electrical resistivity, viscosity and liquidus temperature, essential for efficient ESR operation. Since electrical resistivity and viscosity are highly dependent on the ionic structure of the molten slag, it is important to understand the effect of compositional modification on the structure of the flux. The present study employs Fourier-transform infrared spectroscopy (FT-IR) and Raman spectroscopy to investigate the structural variations in the modified fluxes, especially the effect of changing SiO2 concentration, in comparison with conventional CaF2-rich fluxes. Additionally, thermal analysis (Differential Thermal Analysis (DTA) and Thermogravimetric Analysis (TGA)) has been carried out to characterise the melting behaviour of the fluxes. The findings are compared with simulations carried out using the FactSage™ software, ver 8.3 (GTT Technologies, Aachen, Germany). Simultaneous analysis of liquidus temperature and the structure is expected to help in identifying the practical suitability of modified ESR flux compositions for industrial implementation.

Jun 19, 2024

By B P. Wrench, N R. Steward, C Wu

A gold mine in southern China has transitioned from an open pit operation to a fully underground mine. An overhand mining method is used which requires the mined stopes to be filled with backfill having an unconfined compressive strength of at least 0.35MPa. Tailings from the process plant is deposited into separate flotation and Carbon in Leach (CIL) tailings storage facilities. The tailings has a high fines content and the thickener on site could only produce a dilute flotation tailings at a solids content of about 30 wt%. This resulted in two undesirable outcomes: the density of flotation tailings in the Tailings Storage Facility (TSF) was significantly lower than planned so that the TSF could not store the life of mine tailings and that the backfill product had to include a high percentage of manufactured aggregate and increased cement content to achieve the required strength. This paper presents results of a tailings study which identified that the flotation TSF would be capable of storing the remaining life of mine tailings if an amended backfill product made up of 100% of flotation tailings could be introduced. A 100% tailings backfill with the addition of 8% cement was developed by classifying the tailings and using the coarser fraction in the backfill. This backfill allowed 60% of the flotation tailings to be placed underground and only the remaining 40% in the flotation TSF. A new thickener was designed and installed to thicken the tailings and rheological testing of the tailings, using a closed loop pilot plant, provided parameters to upgrade the underground reticulation system to deliver cemented backfill to stopes throughout the mine and to deliver thickened tailings to the TSF. The revised design was implemented and has resulted in considerable cost savings. CITATION:Steward, N R, Wrench, B P and Wu, C, 2018. Optimisation of surface tailings storage and tailings backfill – a case study, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 454–464 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By Dmitrievskaya TY, Cheremnykh PA, Kuftinova IV, Yaremenko VN

The comprehensive processing of raw materials and the tendency to waste-free production require the combination of various methods of concentrating mineral resources. Magnetic separation, an ecologically clean method of concentration, is one step in the technological cycle of ore processing, and cleaning and classifying of raw materials. Separators with superconducting magnetic systems cooled by liquid helium are the novel equipment for practical concentration. Recently, high-gradient (HGMS) and open-gradient (OGMS) magnetic separators using the effect of superconductivity have appeared. The separators of the first type are expedient in the head-end of the technological cycle, as they are most efficient for processing of particles 100 ¦m and greater in size. In this case the main task is to obtain pure tailings with a minimum amount of the useful component. This method allows the essential reduction in the cost of the subsequent crushing and grinding, because only the magnetic concentrate is directed to further processing. The separators of the VGMS type are used more efficiently in the final stages of the concentration cycle to condition the end product. The present work is devoted to the theoretical and experimental investigation of the motion of weakly magnetic particles in the working chamber of superconducting separators of the open-gradient magnetic separator (OGMS) and HGMS types. The flat OGMS is equipped by a magnetic system with NbTi racetracks cooled by liquid helium. The chamber is divided into zones by partitions parallel to the plane of the magnetic system. It is shown how, depending on the number of the zones and their depths, the extraction function of the OGMS varies and the transition from the OGMS to the HGMS occurs. The particles 2 mm and less in size are considered. The extraction parameter distribution of the particles was measured for a multicomponent weakly magnetic ore. It was experimentally shown that xD2 is the extraction parameter for the particles in the OGMS on condition that (p-po)D /l8/tl/g

Jan 1, 1993

By S Karosiya, A Sharma, M Jain, N N. Viswanathan, M M. Pande, D Kumar, S Kumar

Desulfurisation of steel during ladle refining is governed by both thermodynamics and kinetics. For effective desulfurisation, thermodynamically, a low partial pressure of oxygen at the steel-slag interface and highly basic slag which possess a large sulfide capacity are desired. Kinetically, the mass transfer coefficient of sulfur in the liquid steel and in the slag determines the rate of desulfurisation. A fast desulfurisation rate is achieved by maintaining sufficiently strong argon stirring of the melt. In the present work, sulfur mass balance for steel and slag was performed after the desulfurisation treatment for several industrial heats. The decrease in the sulfur quantity of the liquid steel was more than the increase in the sulfur quantity of the slag. The discrepancy in the sulfur mass balance suggests that the sulfur could be transferred to: (a) the gas (via slag) phase; or to (b) the refractory (crucible) phase. The preliminary investigation of the refractory samples taken at slag-refractory and steel-refractory interface showed no interaction of sulfur with the refractory. Therefore, the possibility of sulfur transfer to the gas phase was verified by carrying out melting experiments of sulfur containing slag in an argon/air atmosphere. Sulfur containing slag was initially melted in an MgO-C crucible under an argon atmosphere followed by creating the air atmosphere just above the melt. Careful sampling and analysis from the cold spots of the crucible, much above the melt surface, revealed formation of a fibrous structure. Scanning electron microscopy energy dispersive X-ray spectroscopy (SEM-EDS) analysis of these fibrous deposits confirmed the presence of oxides and sulfides. Oxidation of sulfur containing slag under air atmosphere was also performed using a thermogravimetric analysis (TGA) set-up. It showed a constant sulfur loss in the range of 1300– 1500°C. Thermodynamic calculations carried out using FactSage™ ver 8.3 for these experimental conditions are in good agreement with the observed results.

Aug 21, 2024

By S Versace, D Arnott, D Bojcevs, A Shaw

The George Fisher deposit is a significant sediment hosted silver-leadzinc resource located 2 km north of the Hilton Mine in NW Queensland. The George Fisher feasibility project involved the completion of underground and surface drilling programs to delineate Measured and Indicated Resource which could be converted to an Ore Reserve through mining and commercial studies. The geological information which was collected and used for the feasibility study included a major program of diamond drilling, predominantly from underground sites, but with some drilling also completed from surface. All drillcore was geologically and geotechnically logged, sampled and assayed. Data was also collected from underground cross-cut and drive development which was mapped for rocktype, ore distribution, structure and geotechnical condition. This new geological data, generated during the Pre-Feasibility and Feasibility stages, was combined with results of all previous drilling campaigns in the George Fisher area to produce a comprehensive database on which geological modelling and Resource estimation could be based. To allow fast and accurate collection and utilisation of data from the drilling program, digital collection processes were used where possible. This resulted in rapid data entry into the project database, significantly enhanced data quality, 100 per cent data ownership within the project team and increased productivity levels. Processes used during the project data collection program are described, lessons learned are related and suggestions for ænext timeÆ are listed using the benefit of hindsight.

Jan 1, 1998

By Dickson T. J

Slag cleaning is an important part of the pyrometallurgical operations at the Kalgoorlie Nickel Smelter. It is a complex system with many streams of different phases and composition. Some of these streams are very difficult to control and/or monitor. Through the use of a statistical computer package, called Minitab, key relationships affecting the economical operation of the slag cleaning process have been found. Data for the statistical analysis was collected from all possible variables around the appendage.

Jan 1, 1991

Material hardness and environmental factors can limit or restrict conventional blasting techniques and this has led to advancements in the performance and efficiency of ripping. Not all materials can be ripped, however today's technology and experience can help make a reasonable prediction. A ripping versus blasting decision will depend on the total volume of material to be moved, the production capabilities and costs of the ripping tractor(s) and on the size and relative efficiency of drilling and Blasting.

Jan 1, 1995

By Mine F. J, Woods P. H

Waste waters from mine sites may be screened for all constituents of significance as a first step in establishing water quality criteria for protection of aquatic ecosystems. Inductively-coupled plasma mass spectrometry (ICP-MS) offers the capability to screen water samples and digest solutions for virtually all elements in the periodic table. This technique is therefore able to identify elements whose concentrations are elevated in waste waters and may be rarely present in background surface or ground waters. Such elements may be present in waters at only a few ¦g/L. ICP-MS has sufficient sensitivity to detect sub-¦g/L or even ng/L levels of many elements. Waste waters from most mining activities in the Northern Territory have been examined by ICP-MS. The concentration data provide the basis of a contaminant data base. The data can show specific tracers in the ore or mineral itself, subsequently found in waste water. An example is the presence of rhenium in uranium ore. Such trace elements may be present in soluble or insoluble chemical forms and are more useful as indicators when soluble and exemplifying conservative chemical behaviour. The approach described, based on ICP-MS screening of mine site waste waters, together with general physico-chemical variables, provides the most comprehensive means yet available of selecting variables for monitoring programs and ensures that key elements and/or their chemical species are not excluded from monitoring programs.

Jan 1, 1994

By N DavT

Pyritic tailings from the Quirke mine waste management area in Elliot Lake, Ontario were subjected to long-term column leaching experiments in two PVC columns measuring 122 cm in height and 15.2 cm in diameter. At the end of the leaching experiments, the columns were taken apart and sampled at 5 cm intervals for quantitative mineralogical and geochemical characterisation. Each column is represented by a total of ten samples. Polished sections, prepared from the samples, were studied by optical microscopy, scanning electron microscopy, electron microprobe and X-ray diffraction techniques. Mineral quantities were determined based on linear mixing models of whole rock and mineral compositions. Pyrite particle sizes were measured by image analysis interfaced to an electron microprobe. The tailings are coarse-grained (ie 96 per cent passing 75 ¦m) and composed of quartz, K-feldspar, muscovite and pyrite. Pyrite is homogenous and occurs as liberated particles displaying angular to subangular boundaries with strong dissolution features at the end of the leaching experiments. Based on up to 3518 particles measured in a sample, pyrite particle sizes range from 1.7 to 78.6 ¦m. Pyrite concentrations vary from 0.1 to 7.8 wt per cent, depending upon their location from the top of the columns. These correspond to pyrite losses of up to 99 per cent from their original level of 7.2 wt per cent in the upper half of the columns. Pyrite oxidation rates in terms of moles of pyrite oxidised per mole of pyrite per square metre per second were calculated from the effluent data and the measured pyrite particle sizes. The rates vary from 1.71+10-12 to 5.78+10-10 mole+m-2+s-1 within the 1.5 to 3.5 pH range for 10 ¦m particles. These results are comparable with the published oxidation rates at pH 2 where the dissolved oxygen is the only oxidant.

Jan 1, 2003

By R Smart

This paper examines the longer-term predictive capacity of the GAMSPATH computer program (developed by the Alberta Research Council) for a waste rock (sample MS) obtained from the Kaltim Prima Coal (KPC) mine, Kalimantan that contained significant framboidal pyrite. The model was refined by comparison with the net acid generation (NAG) and column leach tests to provide a basis for calibration of the model for both short term and longer-term reaction trends. The oxidation of pyrite during the kinetic NAG test using H2O2 provides oxygen directly at the mineral surface, generating a measured oxidation rate for pyrite of 1.16 + 10-6 mol m-2 s-1, whereas the oxygen diffusion limited rate in the leach column air equilibrated reaction was of the order 10-8 mol m-2 s-1 as calculated from the GAMSPATH thermodynamic database. Results indicated that the oxygen derived from hydrogen peroxide had to be included as a reactant (eg a reacting mineral) in the simulation to account for the direct availability of oxygen at the sulfide mineral surfaces. Optical investigations identified the proportion, particle size, and surface area, of framboidal and euhedral pyrite in sample MS. The reactive surface areas of the two morphologies were very different (eg ratio: 5:1). To manage these two different pyrite morphologies the GAMSPATH thermodynamic database was updated to include framboidal pyrite, with similar thermodynamic properties and oxidation rate to euhedral pyrite but with a particle size based on the size of the individual internal framboid microcrysts. This modification, with framboidal pyrite reaction based on the size of its microcrysts produced results that correlated well with the kinetic NAG and column leach test results when the measured (kinetic NAG test rate) and calculated (column test rate) pyrite oxidation rates were employed. This provided some confidence that the model could be extrapolated to indicate longer-term geochemical reaction trends.

Jan 1, 2003

Papua New Guinea is geologically prospective for large, medium and small mineral discoveries. All profitable developments to date have been very large mines but for every large mine there should be many small mines which could be developed under appropriate circumstances.The Papua New Guinea Government should, with appropriate changes to fiscal, legislative and policy regimes, create a favourable exploration envir-onment to encourage a major increase in exploration by small exploration companies and subsequent discoveries and mine development.

Jan 1, 1994

Contractors have penetrated all areas of the Australian mining industry over the last 15 years. The process started in the WA gold and nickel mines and has since spread around the nation to iron ore, base metals and coal mines.The mine contracting industry has progressed from tentative beginnings in the 80s to the current situation where it is now providing high standards of professional management, safety and workmanship with competent people and high quality plant and equipment.

Jan 1, 1998