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The firing of mass blasts at Isa Mine is a normal operating practice. Both electric and non-electric initiating systems are being used for this purpose. The advantages gained by large firings relate to the Planning, Scheduling, Services and Production functions of Isa Mine. More efficient us"e is made of manpower due to the concentrated charging effort and con- tinuity of the charging operation. In addition, the requirement for ring firing personnel to work at the edge of large stope voids is reduced. Better fragmentation results from the interaction of adjacent detonating rings of blastholes and in flight collisions. With mass blasts there is also less chance of large blocks of ore, created by faults or joints, falling into the stope and creating problems at the drawpoints. The formation of a large tonnage of broken ore facilitates production at scheduled rates from that stope source. The weight of explosive detonating during a mass blast can be considerable. Isa Mine has achieved satisfactory blasting results without excessive ground vibration levels and present knowledge indicates that pillar ground stab- ility has been maintained.

Jan 1, 1978

By Waijun Cheng, Guilin Xie

A microcomputer control system prototype of a Switched Reluctance drive for storage battery electric vehicle in coal mines is developed. The paper introduces the hardware components, the control strategy and the software unit. It is shown that

Jan 1, 1998

By Kanchibolta S. S, Brunton I, Tapia-Vergara F

The Split digital image processing system has been implemented in three Australian mines for analysing the size distribution of rocks from the images taken from muckpiles, conveyor belts and tipping trucks. This paper presents an overview of t

Jan 1, 1998

The use of the heavy media cyclone (HMC) Separation process for the treatment of ores in a particular size range is comparatively new to Australia. The paper describes briefly the principles of HMC operation. Reference is made to early development work, the pilot plant trials and the acceptance of the technique as a mineral dressing process. The Mitchell Cotts pilot plant at Amdel is described briefly and the results of test work on this unit for the processing of a wide variety of ores and ore types are given. Comments are made on the ob- jectives aimed at in the investigation and results are discussed with particular reference to behaviourial differences between ore types. The process is easy to operate, possesses a high capacity-to-unit-size rating and is capable of a high degree of flexibility. Further developments such as specially prepared and graded media for specific applications, automatic media density control and regulation of media consistency by the use of surface ac- tive agents and polymers have increased versa- tility and sensitivity of control to the point where products differing by as little as 0.02 of a specific gravity unit can now be separated with ease.

Jan 1, 1973

The O.K. deposit occurs within a belt of cherts and spilitised basic volcanics near the western margin of the Hodgkinson Province. The tabular to lenticular shape and gross conformability of the ore bodies; the common occurrence of colloform, framboidal and banded textures in the ores; the lack of significant alteration adjacent to the massive ore horizons and the apparent restriction of stockwork mineralization to the foot-wall side of the massive ore zone at the O.K. mine, all favour a syngenetic origin for the massive sulfide bodies. Furthermore, the micro- structural evidence suggests that the ores have undergone the same deformational history as the country rocks. The invariable association of the ores with spilites; the S isotope values and Co-Ni contents of the pyrites, together with the primitive metal assemblage (Fe, Cu, minor Zn) strongly favour a basic magmatic source for the sulfides. It is suggested-that the sulfides were probably precipitated sub aqueous- ly during a hiatus in volcanic activity. The O.K. deposit is of the cupreous pyrite variety, but unlike other well known occurrences of this type, it does not con- stitute part of an ophiolite complex. While the host volcanics exhibit strong ocean floor tholeiitic affinities, no associated ultra

Jan 1, 1978

By Morland R

Recent influence of backfill stability on stope production in the Copper Mine at Mount Isa Mines Limited is described. Changes to the mining process to improve fill stability are described, including increased focus on fill performance, modifications to extraction techniques, increased fill quality, changes to drill and blast practice, and research into backfill stability. Several case studies are described.

Jan 1, 1995

With more difficult economic conditions and increased competition, the Australian exploration industry is allocating increased resources to developing more effective and efficient exploration technologies. A significant number of new techniques have been developed, and Australian companies are now at the forefront of exploration technology worldwide. These should increase the chances of maintaining Australia's leading position in world mining over the long term.

Jan 1, 1987

The mine planning and operational aspects of applying Continuous Surface Miner (CSM) technology to Australian coal strip and open cut mines is investigated for both existing and planned deposits. CSM produc- tivity as a function of geomechanical properties, formation thickness, mechanical availability and in-pit physical constraints, are considered. Productivity and operational costs are derived from current production machines and from first principles.

Jan 1, 1989

By C Zhang, I Canbulat, S Saydam, H Yu, H Chen

Natural rocks are frequently exposed to groundwater and complex geological conditions. Environments with water presence are more susceptible to chemical corrosion, which notably affects rock’s micro properties. Generally, the pH of acid mine drainage in hard rock mines can be low to 5, and the pH of quarrying waste deposits can be below 3. With the expanding scope of mining engineering in aquifers and salty areas, chemical corrosion can also caused by different types and concentrations of anions. The anions can significantly affect rock’s mechanical properties. Therefore, it is critical to emphasise the impact of anion and acid on the mechanical and micro characteristics of rock. This paper commences with an introduction to representative corrosive environments. Then the UCS tests are conducted on granite samples corroded by chloride ions and sulfate ions. Anion has negative effects on the strength of granite. The reason is that certain minerals can react and be dissolved by anions and hydrogen ions, such as Al2O3. Furthermore, the scanning electron microscope (SEM) shows that the roughness of the fracture surface increases with the anion concentration. The effect of acid is notably more pronounced than anion on the micro properties of granite. The initiated fissures and pores also increase with the concentration of SO42- and Cl- ions, which is the micro explanation for the impact of anion on rock strength and stability. Subsequently, the permeability of the granite specimens is tested. The reason that granite performs insensitivity to acid and anion is attributed to its low permeability and high content of inactive oxides, such as quartz. To summarise, anionic and acidic conditions can slightly deteriorate the mechanical and micro properties of granite. While SO42- demonstrates a higher level of corrosiveness on granite than Cl-.

Sep 1, 2024

By Mousset-Jones P, McPherson M. J

This paper explains and discusses a computer program developed to deter- mine the optimum combination of fan pressures that will give a required distribution of airflows in a mine ven- tilation system. The program is based on an existing simulator, VNETPC and two experimentally developed relationships: (1) linearity between fan pressures and added regulator resistances and (2) a non- linear convex function relating the system air power and the fan operating Pressures.

Jan 1, 1988

Incorrect sampling and measurement operations and misunderstanding the components of variability can cause huge economic losses to the mining industry. The main objective of this paper is to illustrate by means of four historical facts how Codelco has been evolving in those issues since the late 1980s. The El Abra bias, the awareness of the different kind of sampling errors and the role of Francis Pitard, the awareness of weighting errors, and the understanding of the components of nature and process variability are described. It has been a slow but a consistent process. Much progress has been achieved but still there are many opportunities for improvement to transit from the tonnage culture to the productivity culture.

Jan 1, 2008

The purpose of this paper is to review recent approaches by regulators, employers and employees and their associations to the introduction of flexible employment practices and the management of fatigue related risk. More importantly, it will focus on developments in our law either through legislative change and cases which have dictated trends. The paper particularly considers the limitations imposed by occupational health and safety legislation to resist or limit the move to flexible workplace practices on the basis that such practices are unsafe.

Jan 1, 2003

The population and the per capila consumption of mineral resources have both grown dramatically during the century past. It is argued that growth will continue through the century ahead but that the magnitudes of undiscovered resources are probably adequate to meet demands. The challenge that the mineral explorer of the future will face is finding deposits beneath several kilometres of barren rock.It is further argued that the principal challenge that society will face in the century ahead is the amelioration of environmental stress.

Jan 1, 1993

By K S. Smith

Mineral-deposit geology, geochemical processes, and biogeochemical processes are fundamental controls on the environmental conditions that exist naturally in mineralised areas prior to mining, and that result from mining and mineral processing. Input from economic geologists and geochemists is therefore crucial to effectively predict, assess, mitigate, and remediate the environmental effects of mineral-resource development. Recent open pit gold mining at Summitville, Colorado , has received intense public scrutiny for a variety of environmental problems, most important of which has been extreme acid drainage. Now a Superfund environmental cleanup site, Summitville exemplifies how economic geology and geochemistry principles: 1. could have been better utilized to first predict and minimise the environmental problems, and 2. can now be used to optimize the environmental cleanup.

Jan 1, 1995

Geological information plays a significant, cost effective role, in the Mt Whaleback iron ore mining operations. The geology and structure are complex. Good communication between the Mine Planning Production Scheduling and Quality Control Sections is the key to utilisation of geological information to its full potential.Drilling and pit face mapping are the two basic sources of detailed data sets which are processed to prepare up to date geological cross sections and benchwise geological plans. This information is used directly for the blast pattern design and production scheduling. Physical ore type estimation is also undertaken. Orebody models are generated from the geological information.

Jan 1, 1990

By S Corbel, P J. T Donchak, W Gorczyk

The Hodgkinson Province numerical modelling project aims to develop an improved understanding of the physical conditions that lead to the localisation of goldbearing fluids within known systems and apply this understanding to the prediction of potential new sites of gold mineralisation. The project follows a series of stages from identifying the key parameters required to construct and test simulations through to reverse engineering of known deposits and ultimately applying the conditions identified in the preliminary stages to predictive simulations. Results of the modelling demonstrate strong geometric controls of the localisation of fluids during mineralisation. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By George CW

Western Mining Corporation (W.M.C.)operate a 30 000 tpa nickel refinery at Kwinana, W.A. using the Sherritt Gordon Process. Following ammonia/air leaching of sulphideminerals and subsequent copper removal, nickel metal is produced as powder by hydrogen red-uction of the ammonium sulphate-rich solution. Batchwise reduction in pressure autoclaves is preceded by an oxidation/hydrolysis step to ensure nickel powder quality.The reduction process is energy intensive, requiring high temperatures and pressures. Present energy requirement is 24 GJ per tonne of nickel reduced. Of this, 95% represents steam and hydrogen consumption and 5% electric power. The design and operation of the red-uction circuit is reviewed, outlining the main areas of steam and hydrogen usage.

Jan 1, 1985

By P J. Hawke

Within the Mesa J pisolitic iron ore mine, clay is distributed unevenly throughout the deposit and often forms as pods and channels less than 10 m in width. The mine resource model, based on 50 m + 50 m spaced drilling, has been unable to accurately delineate the clay for scheduling and mining purposes. Therefore, alternative methods for mapping the clay-contaminated ore were sought. Predictive clay mapping will significantly reduce production costs at Mesa J through improved selective mining practices, more accurate scheduling, reduced wear on mining equipment and minimising the need for maintenance of haul roads and ramps. High lateral resolution electromagnetic (EM) surveying using a Geonics EM31 instrument can quickly and inexpensively delineate the extent and orientation of the clays. Preliminary results indicate that a block model based on the interpretation of the EM data can accurately predict the distribution, volume and tonnage of ore and waste material. While rip-line mapping, infill drilling, ground penetrating radar and gravity can delineate clay with various degrees of success, none were as efficient as EM31.

Jan 1, 2002

By Mouritz M

Ventilation characteristics and the occurrence of nocturnal surface inversions have been investigated within the Mount Whaleback open cut iron ore mine at Newman in Western Australia. When winds are light and/or nocturnal surface inversions form within the pit, episodes of atmospheric stagnation can occur with resultant accumulation of dust, diesel exhaust fumes, and sulphur dioxide evolved from spontaneous combustion of pyritic shale. Nocturnal surface inversions were recorded outside the mine on more than two-thirds of nights. Inside the pit, inversions were much less frequent - occurring on roughly 20% of nights when they were observed outside - and much weaker - the maximum temperature difference being 5 C¦ over 210 m inside the pit compared with 15 C¦ over 150 m outside.

Jan 1, 1988

By Smith KS

Mineral-deposit geology, geochemical processes, and biogeochemical processes are fundamental controls on the environmental conditions that exist naturally in mineralized areas prior to mining, and that result from mining and mineral processing. Input from economic geologists and geochemists is therefore crucial to effectively predict, assess, mitigate, and remediate the environmental effects of mineral-resource development. Recent open pit gold mining at Summitville, Colorado, has received intense public scrutiny for a variety of environmental problems, most important of which has been extreme acid drainage. Now a Superfund environmental cleanup site, Summitville exemplifies how economic geology and geochemistry principles (1) could have been better utilized to first predict and minimize the environmental problems, and (2) can now be used to optimize the environmental cleanup.

Jan 1, 1995