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By Yan D. S

The removal of antimony from a refractory gold-bearing stibnite ore by roasting and selective chlorinating roasting was investigated. The influence of roasting temperature, roasting time, roasting atmosphere and type and amount of chlorinating agents on antimony removal were studied. The laboratory studies carried out included roasting tests of 4 g samples in a laboratory rotary kiln, followed by 400 g samples roasted in a fluidised bed. The test results revealed that antimony was efficiently removed by roasting at temperatures over 800¦C in a nitrogen atmosphere. The most efficient volatilisation of antimony was achieved with the addition of ferric chloride at temperatures between 350-600¦C.

Jan 1, 1995

The relevant characteristic of the evolution of the Pacific continental margin of South America during the Mesozoic-Early Cenozoic has been tectonic segmentation. This has controlled suc-cesive episodes of sedimentary accumula-tion, extrusive and intrusive magmatism and deformation that ocurred at conver-vergent plate edges. During this inter-val, at least three main transverse boundaries played an important role conditioning the existence of paleo-segments of different longitudinal extent at various Periods. These probably correspond to deep-seated faults in the Huancabamba Deflection and at the Arica-Santa Cruz Line; the third boundary projects westward to the Chile Ridge. Tectonic activity appears to have been continous at the Huancabamba Deflection at least since the Triassic. The Arica-Santa Cruz Line was probably an active boundary during the Triassic and Cretaceous; the southernmost boundary may have started to be active at the end of the Jurassic. This tectonic activity has determined the subsidence - uplift and paleogeographic conditions of the paleosegments.

Jan 1, 1990

This paper examines the impact of the time value of money on the location of mining facilities, as examplified by a central processing plant serving several mines. Three approaches, the Euclidean-Distance Approach, the Gravity Centre Approach, and the Rectilinear-Distance Approach, commonly applied to a single facility location problem were employed in the study. The objective function in all three models was the updated value of the following three costs influenced by the processing plant location and defined within the framework of the continuous model of value representation and the continuous interest rate convention: I. the costs of transporting the useful mineral from the mines to the plant, 2. the costs of constructing the transportation links between the mines and the plant, and 3. the costs of maintaining these links over time. Results of the study show a substantial impact of the time value of money on both the processing plant optimal location and the opportunity cost of neglecting the time value of money in the locational considerations.

Jan 1, 1995

Hydraulic transport of coal has been used for many years on the West Coast of New Zealand to extract small blocks of steeply dipping coal. Recent development at Strongman 2 Mine has seen the use of high pressure monitors to cut coal and a corresponding increase in the scale of production.This paper provides a brief introduction to hydraulic mining, describes the present system used at Strongman 2 and discusses future potential development.

Jan 1, 1998

By Thornton D, Esterle J, La Rosa D

Control of blast fragmentation has a significant impact on coal mine profitability. Two approaches for the characterisation of coal blastability, particularly in terms of fines, are presented. Both approaches were implemented for the predictio

Jan 1, 1998

By Omnes G

Sixty Schlumberger electrical soundings were carried out in the Depot Springs area, near Agnew, Western Australia as part of an investigation into the availability of groundwater for the Agnew nickel project. The object of the survey was to locate calcrete aquifers related to Tertiary drainage channels on the Pre- Cambrian surface. The electrical soundings were initially interpreted using sets of master curves and auxiliary point methods. Electrical sections were produced and contour maps prepared of apparent resistivity for AB=80m, total conductance of the overburden and transverse resistance.

Jan 1, 1975

By Freeman N

A microcomputer based control system has been developed and implemented at ZC Mines (now Pasminco Mining). The control system maximises throughput at a product size set point while maintaining a "safe" cyclone underflow and mill operating pulp density.To characterise mill and cyclone operation over a range of ore types, 60 circuit surveys were carried out by ZC Mines personnel over a period of four months. The data for each test were model fitted to check for data consistency and to accurately estimate circulating loads.The model fitted results were combined with instrument readings (including in-stream analysis probe assays) and the data checked for ability to predict key variables such as product size and underflow density from measurable inputs.In the resulting control scheme, panicle size and underflow density are not monitored directly, but are predicted by regression equation models based on directly measured variables. The tonnage control loop uses a dynamic model to maximise responsiveness.The system provides a data log output to an mM compatible personal computer at programmable intervals. Comparative data logging over a period demonstrates substantially smoothed circuit performance.The grinding control system was originally implemented using Fischer and Porter micro-DCI controllers. The program has also been implemented on a distributed control system using a sequence oriented programming language.

Jan 1, 1990

By Liu C. H, Juang Y. F

Coal/gas outbursts were one of the rather difficult safety problems faced in the coal mines of this Country, with coal fields characterized by frequent disturbances of folds, faults and pinch-offs. With average mining depth about 500m below surface, several such accidents occurred with up to 500 tonnes of coal outburst. In recent years, after a series of improving countermeasures had been undertaken, gas outburst accidents had been greatly decreased. The characteristics of gas outbursts in Taiwan coal mines include relating to coal petrography, mining depth and the other deformation forces. All these have been investigated, trying to determine the parameter of outbursts under natural conditions. The preventive countermeasures include predicting tests, de-stressing boring in coal seams, the emergency procedures during outbursts and certain improving options.

Jan 1, 1988

Mining software systems have provided a basis for integration of resource, survey, and design functions. They can similarly provide a basis for incorporating ground conditions into the process.Exploration and mine geologists have a prime role to play in this process, extending their responsibilities further across the geological spectrum, into exploration of ground conditions, analyses of results, and assessments of their implications for mining. Ground conditions are as much a part of the geology of a prospect or mine as its mineralisation, and can have critical imnlicationa for mining.

Jan 1, 1993

By Muir DM, Tsuchida N, Dalton R

The adsorption or loading of anions onto extruded based peat activated charcoal has been studied by potential measurements in a flow through cell. Loading rates are in the order F-

Jan 1, 1984

Expert systems are a product of Artificial Intelligence (AI), a field of long standing, dedicated to the study of problem solving using heuristics, construction of symbolic representations of knowledge about the world, communications proce

Jan 1, 1998

A failure of the Pit IA highwall in July 1989 led Newcrest Mining Ltd's Telfer Gold Mine to commence underground operations approximately 12 months ahead of schedule. The failure presented four major challenges to management: 1. how to maximise the recovery of the Middle Vale Reef (MVR) in the open pit: 2. how to minimise the risk to personnel involved in the extraction of the remaining open pit ore; 3. how to avoid disruption to ore supply: and 4. how to maintain a permanent and safe means of accessing the underground operations from the base of the pit. The risks associated with meeting these challenges were minimised through the installation of a complex network of real time slope monitoring equipment. These monitors were connected to an alarm system which was combined with detailed operational procedures to be carried out in the event of a highwall alarm being triggered. The accuracy with which the risk of failure has been managed was demonstrated recently when the onset of a second failure was initially identified some 13 months prior to its ultimate collapse in October 1992. The location, timing and size of the failure was able to be predicted allowing appropriate precautionary measures to be taken to ensure safety of access to the underground portal and pumping equipment in the base of the pit. This paper reviews the sequence of events leading to both the July 1989 and October 1992 failures of the Pit 1A highwall and the monitoring equipment and procedures used to identify, quantify and manage the risk to personnel operating in the base of the pit.

Jan 1, 1994

Drag pick roadheaders and continuous miners have been applied in the coal mining industry for several decades, having replaced drill-blast methods as the primary means of excavating coal and coal-measures strata. The generally harder rock types associated with metalliferous mining have precluded the use of such machines in the past, however, developments in machine technology and increasing labour costs and environmental constraints suggest that there are now likely to be applications suited to the method. Metalliferous mining engineers are generally unfamiliar with the machines themselves and with the fundamental criteria controlling rock cuttability. This paper gives an introduction to the machines and the controlling factors.

Jan 1, 1987

Revised throughput rates, as a result of current mining methods and tight controls on mine dilution, have dictated a change in metallurgical philosophy at Renison Limited. Emphasis on throughput capacity increases has altered to a reduction in circuit complexity and operating costs. Extensive surveys of the gravity and cassiterite flotation circuits led to several plant modifications between August 1989 and March 1990. The coarse and fine gravity retreatment roughing tables were by-passed, the coarse gravity retreatment roughing tables were re-commissioned, the cassiterite flotation rougher capacity expanded and the gravity regrind cyclones re-configured.

Jan 1, 1991

By M E. Watson

Minimising dilution and ore loss is an important part of ensuring profitability of a gold mining operation. White Foil open pit gold deposit is a low-grade deposit and therefore managing ore quality is a high priority. Ground movement through blasting can displace ore and waste boundaries up to 10 m from their in situ location and therefore requires stringent ore movement monitoring and adjustment. There are currently only two options for monitoring blast movement – utilising visual targets (commonly lengths of polypipe) but this has widely been replaced by electronic blast movement monitors (or BMM). Regardless of the technology used, the basic principle is to compare the pre- and post-blast locations of the targets to determine the movement of the rock mass during blasting, which is then used to determine the final location of ore and waste boundaries.The Blast Movement Technologies (BMT) BMM system has been used at White Foil since June 2014. The system has been effective and reliable during that time; however, the annual cost of using the BMM system is greater than other monitoring alternatives. As such, the open pit geology team conducted a study comparing the BMM system against the conventional polypipe technique. The objective was to quantify the profit and loss that would occur based on the ore block transformations from both methods. Eight blasts were selected where polypipes were installed in additional holes adjacent to the BMM monitoring holes. The resulting movement vectors from the respective methods were used to create post-blast ore blocks by transforming the in situ ore blocks. While polypipe is a cheaper alternative, the BMM system tracks ore and waste boundaries more effectively resulting in better quality control, enhanced ability to minimise dilution and ore loss thus maximising profit. For these eight blasts, it is calculated that the BMM system resulted in A$664 978 extra profit through a reduction of ore loss. The total cost of a yearly BMM package was recovered in the first two blasts of this study. The primary reason for the difference is that polypipe had a poor recovery rate of 32 per cent compared with 92 per cent for BMM at White Foil. Therefore, the data used to transform the ore blocks was less representative, resulting in inaccurate post-blast ore block boundaries when using polypipe.CITATION:Watson, M E, 2017. Blast movement monitors or polypipe? A study into cost-effective blast movement monitoring at White Foil gold mine, Western Australia, in Proceedings Tenth International Mining Geology Conference 2017, pp 433–440 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By McNabb KE, Ward B, Dyer G

Roof conditions at Southern Colliery, the second longwall mine to be established at German Creek, were found to be much stronger and more massive than at the earlier longwall mine on the lease. Investigations were made to ascertain the level of face support required for longwall extraction under the changed geological conditions. Geotechnical information was provided from drillholes and highwall exposures. Downhole geophysical logs, notably the sonic velocity log, were used to obtain a distribution of the major lithological units over the mine area. A representative type section of the strata and geomechanical properties was compiled to form the basis for numerical modelling. Two-dimensional finite element methods were used to predict strata movements and chock loads under cantilevered roof conditions. The model incorporated a 6.3 in thick roof beam either bonded or detached, with either a 2 in or 5 in overhang. The solid rib, immediate roof, chock support and goaf were modelled as distinct parts, in addition a front abutment stress profile, derived from three-dimensional displacement-discontinuity analysis, was superimposed on the model.

Jan 1, 1992

LESLIE BRADFORD GOLDEN JUBILEE ORATION "Not only a metallurgist but a scientist of the highest order" Leslie Bradford and the Australian Metallurgical Industry

Jan 1, 1987

By Kendall W. T C

This paper provides a brief overview of the history of the Chaffers Dewatering Project which was successfully commissioned in August 1993. Until the end of 1992 the `Superpit' and the deep mines of the Golden Mile had all been dewatered by a staged pumping system from the 28 level in the Lake View Shaft, which was removed at that time when the Lake View Mine was absorbed into the Superpit. Feasibility analysis had indicated that adaptation of oil industry technology offered the greatest potential for a low cost solution to the problem of dewatering the open pit and deep mines. A KCGM engineer and one of the authors visited the Jackson oilfields to look at the deep well pumping technology in use there in early-1991. In the final analysis a new dewatering station was established in the 23 level crushing station of the Chaffers Shaft using conventional plunger pumps, but the rising main was screwed 178 mm OD (7 inch) casing the suspended from the surface to a depth of 686 metres, and was installed using oilfield personnel and methods. Only the second installation of its kind in Australia, the project achieved the dewatering objective at about half of the capital cost of the more conventional approach and at lower operating costs as well.

Jan 1, 1995

By Aziz NI, Guo H

Most of the existing models of the mechanisms of drilling and cutting processes are oversimplified in both stress state and failure criterion. On the other hand numerical modelling techniques are a more versatile method with great potential for development. In reviewing drillability and predicting performance of excavation machines the empirical tests, which simulate the physical breakage action in excavating processes are seen to be the best in terms of penetration rate predictability. Future methods of determination of drillability should concern the breakage characteristics and rock abrasivity involved in the two basic types of attack, i.e., percussive and rotary drilling.

Jan 1, 1988

As students progress further into a degree, the decision of vocation selection, and even more importantly û securing employment in a particular industry sector, can become quite daunting. However, with a little initiative, students can overcome these issues by not only researching what employment opportunities exist, but by applying for summer vacation employment. Undergraduate vacation employment, especially with a world-leading hydrometallurgy research organisation such as the Parker Centre, can dramatically alter a studentÆs perspective of particular industries and possibly even alter their selection of vocation pursuits upon graduating. Students can also use vacation employment to enhance their networking capabilities, technical skills and knowledge by dealing with challenging new topics such as sulfur dioxide leaching, which is also discussed in this article.

Jan 1, 2005