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By Paine GG

The in-situ retorting of shallow oil shale deposits is an attractive alternative to the material handling problems of conventional open pit mining techniques, which involve removing overburden, fragmenting and transporting the shale to a fixed retort, and finally disposing of the hot spent shale.For in-situ retorting to be successful, the oil shale has to be fractured and the fragmented rock expanded into a void, to allow controlled propagation of a flame front through the in-situ retort. The principles of cratering with explosives have been used to develop a process for the in-situ fracturing of a thin oil shale deposit overlain by a formation of porous rock. The overlying porous rock formation is first compressed by explosive charges to create voids in the porous rock. The oil shale is then fragmented and pushed in to the voids with separate explosive charges. This paper discusses methods of creating voids in porous rocks with minimal surface disturbance, and then methods of obtaining the most uniform fragmentation of the shale. The whole process can be completed, in practice, in one blast. The results of an experimental blast are presented, and possible modifications are then discussed.

Jan 1, 1985

The paper describes the geology, structure, stress, gas and strata geomechanical properties for Leichhardt Colliery and their reactions to mining.

Jan 1, 1986

The Electrolytic Refining and Smelting Company of Australia Limited (ER&S) operates a copper smelting and refining plant and is situated close to the heart of the highly industrialised area of Port Kembla. In March, 1982 the Company entered into an undertaking with the State Pollution Control Commission (SPCC) to monitor ambient levels of sulphur dioxide (S02) gases present in the atmosphere in the surrounding urban area. Despite the use of a 200 metre high stack for dispersal of the smelter waste gas stream at ER&S, two local suburbs, Warrawong and Primbee were experiencing on occasions high ambient concentrations of S02 resulting in discomfort to local residents. In late March 1982, ER&S installed a highly advanced S02 monitoring system to continuously monitor the levels at Warrawong. The system was extended to include S02 monitoring at Primbee in November 1982, and further extended in June 1983, to include an input of meteorological data. Initially the system was designed to monitor and react to high concentrations of S02 at either of the two monitoring stations. Currently however, refinement is taking place to allow a predictive nature to be built into the system such that it not only reacts to an adverse situation but can predict weather patterns likely to cause high concentrations and thus avoid these events. The entire system is still undergoing a growth and development period, however the results obtained to date are pleasing to both the Company and the SPCC.

Jan 1, 1984

By Smith PE

The main components of face design are the power loader, face conveyor and powered support system and the interaction of these components determines the effectiveness of strata control. A major influence upon the interrelationship of this equipment is the geological environment, of which seam thickness appears to play an important role. Recent thick seam experience indicates a significantly different characteristic behaviour pattern from that observed in thin seams The structural integrity of the face wall is particularly influenced by seam discontinuities such as natural joint planes and mining-induced fractures in the yield zone ahead of the faceline. In addition, the presence of stone bands or dirt partings in the seam offers interfaces for uncontrolled release of blocky material. Some case study experience at British collieries provides a comparison with performance data at a specific location, that highlights the importance of coal face layout and design.

Jan 1, 1986

By G Harbort, V Lawson

Mount Isa Mines Limited operates one of the worldÆs largest underground mines in North West Queensland. ItÆs mining and smelting complex produces copper anode, crude lead bullion (containing silver), and zinc concentrate. Copper is recovered in the Copper Concentrator from chalcopyrite ore, converter smelter slag and rotary holding furnace (RHF) slag via grinding and flotation operations. During 2002 a project to optimise cleaner circuit capacity was commenced. Its aims were to minimise copper losses and minimise slag/chalcopyrite cross contamination by reconfiguring existing flotation equipment and the addition of new flotation capacity. To minimise cross contamination a Jameson Cell was installed and dedicated to cleaning of slag concentrates, which had formerly been conducted by three flotation columns operating in series. The flotation columns were re-configured to operate in parallel and dedicated to upgrading chalcopyrite concentrate. In addition a Jameson Cell was installed to reject entrained copper from a prefloat concentrate consisting of talc and carbonaceous pyrite. This paper discusses the logic behind the cleaner circuit expansion, recent test work relating to the Jameson Cell and the installation and commissioning phases. Difficulties relating to the commissioning are reviewed and the solutions to problems are highlighted. The benefits the reconfigured circuit has provided to Mount Isa Mines are also discussed.

Jan 1, 2003

By K Marler

The Water Act 2000 includes provisions to manage the take of overland flow water. Overland flow water is water that runs across the land after rainfall either before it enters a watercourse, after it leaves a watercourse as floodwater, or after it rises to the surface naturally from underground. To ensure adequate environmental flows and long-term security for water users, it is necessary to balance the amount of water taken as overland flow water and the amount left to flow into watercourses. A water resource plan made under the Water Act 2000 establishes the basis for the sustainable management of this type of water. Of the water resource plans that have been prepared for Queensland catchments, six include provisions to manage the take of overland flow water. This paper discusses some of the common features of these plans and the management approaches adopted. The paper identifies and explains key aspects of the Water Act 2000 framework for managing the take of overland flow water by the mining industry. In particular it explains key concepts of this framework, such as the ability to take overland flow water using existing works, uses of overland flow water that a water resource plan permits, situations where a specific entitlement under the Water Act 2000 is required, and the means for controlling works that take overland flow water. Future initiatives for the regulation and management of overland flow water are then identified and particular challenges for the mining industry associated with using overland flow water highlighted.

Jan 1, 2006

By Rospigliosi RT, Krouse HR

The San Vicente stratabound zinc-lead rhythmite deposit, Peru, is hosted in carbonates of the Late Triassic - Early Jurassic Pucara Group. These strata were deposited in a large, shallow water, carbonate platform which extended nearly continuously for 150 kilometers (north-south) in the eastern part of the Pucara basin.The distinctive sulfide-bearing rhythmites occur in three dolomite units which, from bottom to top, include the San Judas horizon with one sulfide-bearing manto; the San Vicente horizon with seven sulfide-bearing mantos including the main ore horizon; and the Alfonso horizon with three sulfide-bearing mantos. The dark gray sulfide-bearing dolostone layers range in thickness from a few millimeters to a few centimeters and contain variable amounts of carbonaceous material, pyrite, quartz, fine-grained sphalerite and galena. They are bordered on each side by selvages of yellow to red-brown coarse-grained sphalerite containing minor amounts of galena. Coarsely crystalline white or gray sparry dolomite is found between the coarse-grained sphalerite layers. Although commonly stratiform and uniform in thickness, the dark layers curve, "pinch out," coalesce, and form "islands" and "peninsulas."Mineral replacement textures, the paragenetic sequence, and presence of sparry dolomite, bitumen, intraformational breccias and isotope data support a hydrothermal replacement origin by metal-bearing solutions that deposited the ore and related minerals in space previously occupied by dolomite and evaporite minerals. The alignment of the Zn -Pb deposits, and at San Vicente the orientation of the mantos, the spatially and temporally associated igneous sills and the tourmaline-bearing sandstone support hydrothermal mineralization driven by a magmatic heat source in a tensional regime.

Jan 1, 1990

By Selischop F, Tredoux M

The distribution of platinum-group elements (pGEs) has been investigated in matte and slag samples from Waterval Smelter (Rustenburg Platinum Mines). The study showed that a strong preference of PGEs for alloy phases in matte represents a concentration mechanism that commenced in the furnace but can be considered a continuum from natural processes. Metal losses to fayalite (converter) slag occur by matte entrainment due to the mechanical capture of liquid sulphide droplets from the matte layer, and the exsolution of dissolved metal sulphide resulting from changes in the oxidation state of the slag. The latter is comparable to immiscible sulphide in basic magmas. However, the observed distribution of PGEs shows enrichment in metal phases of the matte. A mechanism is proposed whereby naked PGEs in silicate melts coalesce to form clusters which are stabilised by surface attachment of sulphur atoms. This envelope acts to 'draw the cluster into sulphide melts. Small particle melting effects permit PGE clusters to remain as liquids at magmatic and smelter temperatures.

Jan 1, 1994

Bakelite is fairly widely known as a suitable material for the mounting of ore specimens, concentrates and tailings for microscopical study, but has not as yet had extensive application. It is the most suitable mount for specimens which are to be held in the mechanical holder of a polishing machine, based on that described by J. W. Vanderbilt*, which is installed in the Geological Department of the Melbourne University.Bakelite products are prepared by subjecting bakelite powder to a temperature of about 1600 C. under a pressure of approximately two tons per square inch for a period of four minutes. The shape and size of the products are governed by the use of suitably constructed dies. When the concentrate or tailing is mixed with the bakelite powder, a briquette is produced which can be polished so that the opaque minerals in the sample can be examined microscopically in the same way as in a piece of solid ore. A simple machine for the construction of these briquettes has been described by Head and Slavin. It consists of a small four-pillar press in which the pressure is supplied by...

Jan 1, 1933

Recognition is the most important aspect in the use of breccias as an exploration tool. Ore-hosting breccias occur in a wide variety of environ-ments, shapes, compositions and characteristics, but generally present favorable loci for the deposition of ore mineralization in epithermal, porphyry copper-gold-molybdenum, massive sulfide, carbonate-hosted, sedimentary lead-zinc deposits and others.

Jan 1, 1990

By J M TORLACH

Learning is an iterative process, and we might reasonably expect that after more than a century of mining during an era of sustained technological development, (following a millenium or two of unrelieved hard physical graft), that the more obvious physical hazards could by now be competently managed. It is perhaps a reflection on the perversity of human nature that we have not fully learned our lessons in this exacting environment, and that worse, we have still too often failed to profit by the experience of those lessons. The more obvious underlying factors which impact on this situation are examined briefly, as a prelude to consideration of some outstanding examples of recurrent problems experienced in recent years. Reasons for the continued existence of sub-standard practices are outlined, with a focus on the human element, and finally proposals for appropriate remedial strategies are summarised. This paper therefore seeks to examine and discuss some of our deficiences and to suggest some directions for the way ahead.

Jan 1, 1992

The results of about 30 years of exploration and mining activities and research studies in the Kambalda mining district, Western Australia, have led to general agreement that the komatiite-associated Ni sulphide ores formed as a result of igneous processes (Ross, 1974; Ross and Hopkins, 1975; Gresham and Loftus-Hills, 1981; Cowden, 1988; Lesher, 1989 and many others). Despite this agreement, the controls on sulphide supersaturation and concentration of the resulting sulphide in a limited zone, remain uncertain and controversial. A major uncertainty is the source of sulphur in the ore deposits. Two principal sulphur sources have been proposed: 1. komatiite lava/magma (Hudson, 1972; Naldrett, 1973; Lesher et al, 1981; Cowden, 1988; Foster et at, 1995), and 2. sedimentary material (Groves, Barrett and McQueen, 1979; Lesher, Arndt and Groves, 1984; Lesher, 1989; Lesher and Campbell, 1993). Resolution of the uncertainty regarding the sulphur source is required for a complete understanding of the controls on ore formation, which in turn would significantly impact exploration strategies in the Kambalda mining district and elsewhere. This paper reviews the constraints on sulphur sources for the komatiite-associated Ni sulphide ores in the Kambalda mining district. The focus is on the general characteristics of the ores and surrounding rocks: individual ore deposits are not described, though specific examples are noted where appropriate. The stratigraphic and volcanic settings and geochemical (major and trace element and isotopic compositions) characteristics of the ore deposits and surrounding rocks are considered within the context of the competing sulphur source models, and future directions of research in the district are noted.

Jan 1, 1996

By B Crompton, A Berghorst, G Knox

Laboratory-based dynamic testing provides an invaluable tool in the development of rock bolts for use in highly stressed, burst prone rock masses. While in most cases the laboratory-based test method is not a direct comparison to an in-situ installation due to the purely axial loading and variations in boundary conditions, it does provide an indication of the performance of the tendon system under dynamic loading. The aim of the research described in this paper is to provide an understanding of the effect of the impact velocity of the impact mass during a laboratory-based dynamic test. Understanding the effect of boundary conditions of laboratory testing will improve Geotechnical Engineers understanding of the performance in an in-situ installation. In addition, due to the limited number of dynamic test facilities, an understanding of the effects of the boundary conditions will aid in the comparison of test results for different products from different test facilities. The research was conducted using an impact tester, whereby a known mass is raised to a known height defining the kinetic energy and velocity of the mass at the point of impact with the test sample after release. The impact velocity was varied between 2.7 m/s and 5.4 m/s, while the kinetic energy of the mass was maintained at 11.5 kJ. While a correlation between the impact velocity and strain rate of the system tested was established, due to the properties of the system tested, the range of impact velocity on which dynamic tests were conducted was insufficient to result in a considerable change in the average impact load, the cumulative proximal displacement and the cumulative maximum energy absorbed over multiple impulse. However, due to the reduction in the momentum of the impact mass the impact duration and displacement during each impulse in the series of impulses reduced. CITATION:Knox, G, Berghorst, A and Crompton, B, 2018. The relationship between the magnitude of impact velocity per impulse and cumulative absorbed energy capacity of a rock bolt, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 160–169 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By P B. Hills, R J. Walton

Narrow vein tabular orebodies are prone to mining induced seismicity. The Tasmania Mine is a complex example of a seismically active tabular orebody, where the contrasting material properties of the host strata and of the orebody itself, serve to exacerbate the seismic response. Analysis of a continuous record of seismicity over a period of seven years has provided significant insight into the fundamental mechanics of the rock mass. Understanding seismicity to permit safe extraction of the orebody has been enhanced by instrumentation of rock mass behaviour in response to mining and mining induced seismicity. It is the purpose of this paper to explore that understanding in respect to the adoption of an alternative down-hole Avoca stoping method for use in particular circumstances.Intensive instrumentation of the Tasmania Mine over a period of four years has provided insight into the behaviour of the rock mass in response to extraction of the narrow vein orebody it encompasses. A range of instruments have been installed in clusters or single installations in order to measure changing stress conditions and the impact of those changes on the rock mass and the reinforcement system.Instruments are often installed in very close proximity to active production stoping. While it has been possible to observe the impact of the mining and mining induced seismicity at very close quarters, instruments installed in these locations are vulnerable to damage and consequently, the level of instrumentation is high. Instruments are continuously logged, typically on a six hourly basis coinciding with the end of regular blasting times. The response of the instrumentation to changed rock mass conditions is considered against the background of development and production blasting and against the seismic record to assess the viability of downhole Avoca stoping.CITATION:Hills, P B and Walton, R J, 2012. Continued observations of rock mass behaviour in response to stoping at the Tasmania mine, Beaconsfield, Tasmania, in Proceedings Narrow Vein Mining 2012 , pp 169-178 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

The design of a sand pump is similar in principle to that of a water pump but differs in several areas. Results of experiments on sand pump performance have been summarized and values of design parameters quoted for optimum results. Typical performance data are also Included.

Jan 1, 1973

By Walters GW

A countercurrent method of metal refining using crystallization and reflux is discussed. 4n account is given of the development of this technique for the separation of silver and bismuth from lead using bench-scale studies to the present small pilot-plant unit (around one tonne per day) in the "Commonwealth Scientific and Industrial Research Organization (CSIRO)" Division of Chemical Engineering.

Jan 1, 1975

By Hatherly P, Holt GE, McNally G

The current methodology for delineating and subsequently evaluating coal reserves is based on the use of vertical drill holes and surface based geophysics/geology. These techniques have three major problems, these being respectively:-a) Vertical drill holes can only provide a small sample of the coal seam and stratigraphy. Therefore the planar variation in coal reserve and environment parameters can only be approximated.b) Although surface based geophysics has had its fair share of success in recent years, there are still environments which have masked the finding of major structures.c) Access to drill sites is difficult at some locations due to mountaineous terrain, standing water and environmental impact.

Jan 1, 1985

The high maintenance of load-haul-dumps (LHDs) and front end loaders in hard rock affects mine planning with reduced availability and productivity. Intensive study of maintenance costs and availability of machines related to machine age and life provide the basis for planning from available operational alternatives.Derived programmes and experiences have led to the beginnings of unmanned operation and automation through reduction of manual diesel units and spreading electrification and use of radio. But electrification has obvious layout limitations. This approach to the present has resulted in better utilisation, costs and safety and the computerised monitoring and control provides continuous awareness of machine and work conditions with the promise of future improvements.

Jan 1, 1991

By Ofori-Ansah K

The zeta potential on the surface of activated orit carbon were estimated in lhe presence of selected cations and anions that are normally associated with gold bearing ores in Kalgoorlie area of Western Australia. Additions of such ions to solution of varying pH shifted the isoelectric point of carbon from pH 4.45 to pH 7-8.3, while the anions moved Lhc isoelectric point 10 less than pH 3.2. In the presence of gold cyanide SoluLion additions of spectator ions indicated the isoelecLric poilll to be aL pH less than 3.2; the only exception was for Fe" ion where the isoelecLric point was at pH 5.9. The decrease in zeta potential appeared to be related to the counter-ions present. The decrease may also be related to the adsorption of hydroxyl ion complexes that are likely to be formed when cations are present in the solutions.Gold adsorpLion by activated orit carbon from gold cyanide solution seem to be indicated by the magnitude of zeta potential on the carbon surface. An attempt is made to relate gold adsorption and zeta potential on carbon surface with the pH of the medium.

Jan 1, 1984

By Follington I. L

Various methods for stress measurement in the coal industry are briefly reviewed. Methods for presenting and interpretation of measured stress and displacement data are discussed with a view to assessing the mechanisms of failure. Arguments are presented for reviewing the current practices in this regard with reference to coal pillar and strata stability analyses.

Jan 1, 1991