Search Documents

Mineral exploration conducted over a wide area of the State during the period 1960 to 1973 has resulted in the discovery of a number of significant deposits. Base metals, particularly copper, have been of prime interest while, more recently, the search for uranium and coal have assumed import- ance. Expenditure of $27.6 million by companies during the period under re- view has located 580,000 tonnes of cop- per, 370,000 tonnes of zinc, 350,000 tonnes of lead, 24 million Kg of uran- ium oxide and 2,500 million tonnes of coal. A variety of other metals and non metallic and industrial minerals have been investigated in a diversity of geological environments.

Jan 1, 1975

By Binns RA, Murao S

The PACMANUS and Jade deposits are two active hydrothermal fields that are forming massive sulfide deposits at the Pacific rim margin. Both are associated with felsic submarine volcanic rocks and both occur in back-arc settings. However, PACMANUS is associated with almost sediment-free dacites and lies on the crest of a volcanic ridge, whereas Jade occurs in a heavily-sedimented tectonic depression associated with a basement of pumiceous rhyolite. The PACMANUS deposit is richer in Cu and Au, and Jade in Pb. Zinc, Ag, As and Sb contents are similar. Sulfide textures at PACMANUS suggest formation of Cu and Zn sulfides by simultaneous double-diffusion involving inwards-moving seawater mixing with outwards-moving hydrothermal fluid. By contrast, at Jade there is a more complex history of formation where initial growth of barite on the sediment surface, probably associated with microbial activity, formed an impervious cap which trapped higher temperature hydrothermal solutions.

Jan 1, 1995

By Deverux M

Heavy mineral deposits accumulate on shorelines with interrupted sediment input. Beach deposits, which form on shallowly dipping coastal plains, are most favourable. However, shallow shelves seaward of cliffed coastlines are known to contain economic deposits. Significantgeologicalconditions are defined, from review of the stratigraphic and geomorphic controls on known deposits , for heavy mineral accumulation on the Swan Coastal Plain.

Jan 1, 1986

By D L. Decker, G C. Miller, C Papelis

Arsenic, often associated with precious metals ore deposits, is a major contaminant released during large-scale gold mining. Because of the complex oxidation/reduction and sorption behaviour of As, prediction of the long-term mobility of As in pit lakes is uncertain. The behaviour of As in pit lakes is investigated in this paper by conducting a series of laboratory experiments where As is allowed to adsorb onto pit lakes sediments. Experiments were conducted over a range of pH with both As(III) and As(V) allowed to adsorb onto sediments collected from existing pit lakes found in the three main orebody types in Nevada, USA; porphyry copper, quartz-adularia gold, and Carlin Trend type gold deposits. Results from adsorption experiments show that As(V) and As(III) adsorption is strongly pH dependent with higher uptake at pH 5 and lower uptake at pH 9 for As(V) and higher uptake at pH 9 and lower uptake at pH 5 for As(III). This behaviour, as expected for oxyanions, has been described previously for agricultural soils, iron oxides, and Carlin Trend heap materials. Maximum adsorption of As(V) for the Carlin Trend type gold sediment was 3.0 g/kg at pH 5, 2.0 g/kg for the quartz-adularia sediment, and 0.9 g/kg for the copper porphyry sediment. Maximum adsorption of As(III) for Carlin Trend type gold sediment was 2.5 g/kg at pH 9, 2.2 g/kg for the quartz-adularia sediment, and 2.1 for the copper porphyry sediment. Adsorption isotherms are non-linear and show Freundlich isotherm behaviour. Variations in sorption between the different pit lake sediments under similar conditions can be explained by differences in the elemental composition of the sediment. Most rock forming elements from XRF analysis are similar in quantity except for Fe. The Fe content is highest in the Carlin Trend type gold deposit sediments and lowest in porphyry copper deposit sediments and is the third most abundant element in all three sediments. The Fe content of the sediments correlates well with the amount of As sorption seen in the laboratory experiments.

Jan 1, 2003

By P Fines, D J. Williams, G W, S Miller

This paper presents the results and findings of geochemical and mineralogical testwork conducted on samples collected from waste rock dumps at two mine sites, located in South Carolina, USA (Site 1) and Sudbury Ontario, Canada (Site 2). Important aspects of the relationship between the physical and geochemical aspects of the dumps are also presented. The overall aims of the project were to 1. determine if the physical and hydrological nature of the waste-rock dumps had any impact on the geochemical and mineralogical characteristics of the dump materials; and 2. to identify key implications for dump construction for ARD control. The results of geochemical and mineralogical tests indicate that the waste rock at Site 1 had undergone significant in-dump weathering and was relatively advanced with respect to ARD evolution. In contrast, the waste rock at Site 2 had undergone some weathering, however still contained a considerable amount of sulfide minerals. Testing also suggested that flushing of oxidation products at Site 2 had been limited, which therefore promoted the storage of oxidation products at the site. In addition, materials that had a D50 particle size in the range of 5 mm to 30 mm appeared to be more readily flushed than samples that had a D50 particle size of 30 mm. This suggested that preferential water pathways may have developed within the dumps at both sites.

Jan 1, 2003

According to the temporal and spatial distribution of regional metallogenesis, the Pacific Rim can be divided into four global metallogenetic systems. The Asia-Australia W-Sn metallogenetic belt is the typical representative of intracontinen- tal metallogenetic systems. This belt resulted from Mesozoic and partly pre-Mesozoic tectonic magmatism, mainly re- lated to S-type granite of crustal source, that was generated by collisional orogeny combined with oceanic subduction in intracontinental and continental margin settings. Based on the concept of metallogenetic series, there is a group of min- eralised ore types showing a definite spatial and temporal distribution from endogenetic to exogenetic. These metalloge- netic series are widely distributed in the Asia-Australia W-Sn metallogenetic belt, and are well developed in Southeast China. Five metallogenetic series and two petro-minerogenesis evolution models have been established according to their tectonic settings, various types of granitoids and metallogenetic evolution.

Jan 1, 1995

By P Knights, M S. Kizil

Truck/shovel operations constitute 50 - 60 per cent of the cost of open pit mining operations. Mining companies, therefore, are constantly seeking to close the gap between actual truck/shovel productive capacity and maximum potential truck/shovel capacity. This paper analyses the performance of a mixed truck/shovel fleet in an open cut coal mine in Australia. It analyses operating delays, and proposes a novel graphical means of determining truck-limited or shovel-limited operations. A goal seeking algorithm is advanced in order to maximise truck/shovel match factors (MF) and hence optimise fleet productivity.

Sep 26, 2011

The impact of computers on the mining industry has increased for the past twenty years in most parts of the world. The application of computers in the mining industry has been demonstrated in areas such as geological data analysis, ore reserve estimation, mine planning, and manpower training. There is also a general concern in this country regarding the computing background of graduating mining engineers from the Australian higher institutions of learning. This paper describes specific steps which have been taken at the Department of Civil and Mining Engineering, The University of Wollongong to provide adequate computing background to mining engineering graduates. Specific topics discussed include hardware and software available to students and how "computers" have been integrated into the mining engineering course.

Jan 1, 1986

By Coskun B

The classification of selective mining units (SMU's) and the assignment of grades to those classified SMU's are very important in open pit mining, especially for precious metal mining. During ore control planning, the classification of mineral

Jan 1, 1998

Recent research publications in extractive metallurgy were analysed for their stated and self-evident objectives. Over 100 different objectives (not specific to a metal or unit operation) were identified. These were divided into groups of economic, environmental, professional and fundamental significance. Comparisons were made of the objectives adopted in universities, industry and national research organisations. The most common primary and secondary objectives (by a large margin) were "to develop a new process (different chemistry)" and "to determine the effects of variables on a process" respectively. It was concluded that, overall, recent research has been dominated by commercial objectives. Objectives related to thermodynamics and kinetics have been the most common of the fundamental sort. Those related to professional methods in general, sensors and process dynamics, among others, have been largely neglected.

Jan 1, 1986

Operations at two open cut mines have so far commenced on two out of the five potentially mineable seams in the Fair Hill - German Creek Coal Measures. Due to seam splitting, up to seven mining units are present in the Dysart Seam interval at Peak Downs giving a total of 12 mining units in the section. The coal is low to medium volatile type and produces strong coke. Rank increases and fluidity decreases in the southern part of the area.

Jan 1, 1974

The process of establishing the design criteria is the key step in commencing a new project.. The method for establishing design criteria and translating them to a workable plant design is described. INTRODUCTION The use of activated charcoal to recover gold from alkaline cyanide leach liquors is the most rapidly expanding technology in hydrometallurgy today. The process, known as carbon-in-pulp (CIP), has replaced countercurrent decantation as the method for recovering gold by cyanidation. Carbon-in-pulp entails mixing activated charcoal with a ground ore-water slurry containing gold cyanide, allowing the charcoal to adsorb the gold, and then mechanically removing the gold loaded charcoal from the pulp. The pulp is sent to tailing disposal and the loaded charcoal is sent for gold bullion production. Activated charcoal's affinity for gold has been docu- mented for over one hundred years. In the first cyanide plants, one of the preferred methods of stealing gold was to place a piece

Jan 1, 1982

By B Goebel, G Baker

The Australian Magnesium Corporation Limited (AMC) is constructing the worldÆs largest magnesium metal plant at Stanwell, 24 km west of Rockhampton in Central Queensland. The $1.3 billion, 97 000 tonne per year plant is scheduled to commence production in mid-2004. It will produce magnesium from magnesite using the innovative, locally developed AM Process Technology which enables magnesium to be produced at internationally competitive costs. The technology will enable the plant to have the lowest environmental impact of all the available magnesium production processes. The project will meet current world-best-practice environmental and emission standards while on a life cycle analysis, magnesium produced by the Stanwell plant will result in net reduction in global greenhouse gas emissions. Magnesium is the lightest of the structural metals. Its high strength to weight ratio and ease of casting and machinability makes it particularly suitable for the manufacture of light weight automotive components. Reducing the weight of motor vehicles through the use of light weight materials such as magnesium is the current primary means adopted by the automobile manufacturing industry to improve motor vehicle fuel efficiency and the lowering of emissions of greenhouse gases. The Australian Magnesium or AM process has been developed over the past decade by AMC in conjunction with the CSIRO to produce magnesium from magnesite mined at AMCÆs Kunwarara deposit. Over $200 million has been spent developing the AM process, designing, building and operating a demonstration plant at Gladstone and to complete an environmental impact statement and receive environmental approvals as well as funding for the commercial Stanwell Project. The paper outlines the development of the AM process technology, the operations of the Gladstone demonstration plant confirming the process technology, its operating costs and environmental performance. The paper covers the particular attention that was given to minimising the production of CHCÆs, the development of new cover gases for molten magnesium, the minimising of emissions of greenhouse gases and the life cycle analysis of magnesium as a replacement for steel and heavier metals in motor vehicles which confirmed its use resulted in a net reduction in global greenhouse gas emissions. The project received both Commonwealth and Queensland Government environmental approvals by August 2000.

Jan 1, 2002

Pyrrhotite is pyrophoric when in a finely divided form. The problems of disposing of large quantities of finely divided pyrrhotite separated out by metallurgical processing from ore are formidable. In the case of an underground mine, a solution to the problem of disposal is to place the pyrrhotite in the stoped out areas and seal from any air supply. Further, the pyrrhotite could be diluted with tailings which would reduce the possibility of combust- ion. Several enquiries to various centres and authorities have shown that the products of the slow oxidation of pyrrhotite with moisture present can cement an inert matrix into a stable fill similar in physical prop- erties to fill stabilised with Portland cement. Stabilised fill can be used to advan tage with a suitable mining method to provide high recovery. The investigation demonstrated that air and 15% w/w water must be present for the fill to harden and that the sizing of the particles is a critical factor in drainage of a hydraul- ically placed fill and subsequent even harden- ing of the fill in a stope. With the materials used in the experiments in which the - 51 micron component of the tailings had been dis- carded, an optimum mix was found to contain 4:1 tailings/slag ratio and an overall pyrr hotite concentration of 8% (all proportion by weight). Approximately 34 days after drain- age to 15% moisture in natural air flow condit- ions, an unconfined compressive strength of 1.862 MPa was attained. A subsequent experi- ment was conducted with a sample of optimum mix in a pipe one metre long in forced air flow conditions. At a superficial velocity of 3.Om per hour the mix required 155 hours to harden to 1.862 MPa after drainage to 15% w/w moisture content. The pressure drop bet- ween the top and bottom of the mix in the pipe remained constant at 9 KPa/metre length. This result suggests that forced air flow conditions will increase the rate of hardening. No dangerous effluents were detected in the course of the experiments which could affect mine equipment or personnel.

Jan 1, 1973

By K Kuganathan

This paper describes a new methodology that can be applied to compare several bench extraction strategies requiring backfill. The method is applicable at the planning or operational stages and can be used to maintain dilution within design parameters and improve the overall economics of bench stoping operations. The parameters influencing bench performance have been empirically rated based on economical, geomechanical, operational and backfill properties. Four different extraction strategies have been considered and rated from most preferred to less preferred using an integrated approach to bench extraction.

Jan 1, 1998

By Dickson B. L

Groundwater geochemistry is controlled by chemical interactions with aquifer rocks, and offers a powerful geochemical exploration technique for locating concealed mineral- isation. Techniques are applied for identifying constituents of aquifers using the compositions of their groundwaters, collected from the surface through drill holes, water bores or springs. Even slowly moving groundwaters have passed through large volumes of rocks which surround any sample site. Products from these rock-water contacts modify the groundwater. By relating water composition to the minerals from which the dissolved species may have been derived, geochemical exploration information is obtained for a significantly larger zone than is represented by drill hole rock samples. In this paper we describe some solution chemical tech- niques we are applying in mineral exploration, particularly in areas of Australia where ground- waters are highly saline and contain enhanced concentrations of trace metals. EQUILIBRIUM MODELS FOR SALINE GROUNDWATERS Central to our technique is the assumption that in low rainfall regions, aquifer rocks and contained groundwaters are in chemical equili- brium. Solubility calculations then allow us to predict upper limits to the soluble products of groundwater interaction with aquifer rocks and to identify minerals with which the groundwater is saturated. Whilst equilibrium calculations require input of concentrations of all dissolved species, they are actually based on "activity" of dissolved species rather than the analysed concentrations. Unless waters have very low ionic strengths (a measure of total dissolved solids), activity of a solute is not equal to its analytical concentration but equals concentration multiplied by an "activity coefficent". Several methods exist for calculating mineral solubilities. The ion-association model, commonly used in programs such as WATEQ (Truesdell and Jones, 1974) and later deriv- atives such as MINTEQ, assume the formation of complex ions such as MgSO4(0), CaCl+, which are described by formation constants. Activity coefficients are obtained by the extended Debye

Jan 1, 1988

By Kohra A, Shoji S

The amount of copper production by flash smelting process occupies about 17% (equivalent to 1.4 million t/year) of total free world production. In Japan, 650,000 tons of copper is produced annually by flash smelting. This is 65% of the gross copper production of Japan. To reinforce pollution control, promote energy saving, and enhance production efficiency by increasing the size of furnaces, conventional blast furnaces and reverberatory furnaces are being replaced with the flash smelters worldwide. The Ashio Smelter started copper production in 1884 and developed in association with the Ashio mine. In those days, the Ashio smelter produced copper by using the blast furnace process designed for the high-grade ore from the copper mine. At that time, this process was specialized in Japan. In 1956, for the first time in Japan, the Ashio Smelter introduced the flash smelting process developed by Outokumpu Oy of Finland (it is suitable for treating the copper concentrate, producing sulfuric acid and improving production efficiency). The flash furnace in Ashio, the first ever in Japan, had a capacity of 230 t/day for copper concentrate and was operated up to 1962. During this period, various operational troubles were solved, and further improvements were made; and, in 1962, a Furukawa-type flash smelting furnace was completed in Ashio. This improved version of a flash furnace had a capacity of 450 t/day. There was one flash furnace and one waste heat boiler, which were arranged in a unique pattern for that time. This furnace may be said to be the prototype of the present flash smelting process in the world.

Jan 1, 1987

By O Otgonbayar, B Bayarmaa, D Batbyamba, S Amar-Amgalan, K H. Natsagdorj, J Nomin-Erdene, B Boldkhuu, T S. Sainzaya

The Argyle deposit in the Kimberley region of Western Australia was the world’s largest accumulation of natural diamonds. Following its discovery in 1979, the mining of associated alluvial diamonds commenced in 1983, followed by the pipe in late 1985. Over the life of the mine to its closure in November 2020, Argyle produced approximately 900 million carats of diamonds. Argyle diamonds are distinctive in having a predominance of brown colours and rare highly-prized pink diamonds, which are a signature of the deposit. The 3D geological model developed from mining and deep drilling shows that Argyle is a composite pipe formed by the coalescence of several steep-sided diatremes, each with their own feeder zones at depth, that were erupted along a NNE-trending fault. The ~1.2 Ga Argyle pipe is comprised of diamondiferous olivine lamproite volcaniclastic rocks and intruded by sparse olivine lamproite dykes. The volcaniclastic rocks are predominantly comprised of unconsolidated quartz-rich lapilli and coarse ash deposits formed by numerous phreatomagmatic eruptions of olivine lamproite magma through Mesoproterozoic water-rich sands and silts. Post-emplacement deformation has tilted the orebody 30° to the north and regional strike-slip faulting has offset, segmented, and elongated the orebody. Recent significant modifications of the geological model resulted from underground block cave operations, producing several critical lessons learnt. Diamond grade and quality reconciliation issues warranted a geological investigation which resulted in the recognition of new volcaniclastic olivine lamproite domains with a broad range of diamond grades, including some very high-grade units. The new lamproite domains had a significant effect on the block cave mining and resultant recovery of diamonds. The new findings enable a more coherent and detailed geological understanding of the volcanic emplacement and paragenetic sequence of the Argyle AK1 pipe. Structural modelling of the deposit also played a major role in the block cave mining tonnage recoveries and daily operations. The re-examination of the geology of the Argyle pipe and the results of this new information reinforces the need for ongoing robust geological work both in the early stages of mining a deposit and continued during the life of the mine.

Mar 22, 2022

By Mills KW

Coal mine pillar design formulae available to mine planners are typically based on relationships determined for specific site conditions. Application of these methods is difficult when other factors, relating to mining or geological conditions, not specifically addressed in these relationships are encountered. A review of pillar design methods, coal strength properties and relevant field monitoring of pillar behaviour has shown pillar strength and deformational characteristics are extremely sensitive to in situ behaviour of the rock and other material components that make up the coal pillar system. A method has been developed that has been found to provide excellent correlation between existing field data using the strength and deformational characteristics of materials determined in selected laboratory tests. This method is based on definition of the loading conditions, accurate modelling of the strength, confining conditions and deformation occuring in the roof, floor and coal seam and definition of the in situ strength of coal based on underground monitoring of appropriately sized coal pillar. The design method is considered to provide an accurate and rigorous pillar design method that will give mine planners a more rational mine design capability which is based on the mine geometry and geological setting of the operation. It is envisaged that availability of such a method will allow significant optimisation of pillar layouts and more closely define the geological and mining issues that relate to pillar design optimisation.

Jan 1, 1992

Relationships between lead blast furnace performance and the composition and size distribution of sinter were determined from analysis of lead blast furnace operating data. Sintering plant practice was subsequently modified and substantially improved furnace performance resulted.

Jan 1, 1971