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The mineral matter has been isolated from a selection of Australian bituminous coals using low temperature (radio-frequency) oxidation or hydrogen peroxidation techniques and the species present identified by x-raydiffraction. Quartz, kaolinite, and a range of mixed layer clay minerals are the dominant constituents of the coals studied, with carbonate, sulphate, and phosphate minerals abundant in some samples. The clay bands thatoccur within these coal seams contain similar mineral assemblages to the coals themselves, but the lutites that form the inter-seam strata have a markedly different mineralogy, characterized by abundant quartz andillite and a low kaolinite content.The kaolinite is thought to have formed chiefly by interaction of silica and alumina in the waters of the coal swamp, aided by the catalytic action of organic acids, while most of the other clay minerals are probablydetrital. The absence of illite from Australian coals is not fully understood, but it may reflect the action of organic acids on the detritus in the swamp, coupled with deposition in freshwater rather thanmarine conditions. Pyrite, although present in some coal samples when fresh, may undergo oxidation during storage to form a number of sulphate minerals, some of which may interact with any calcite present toform gypsum.The mineral matter assemblage in the coal determines to a great extent the fusion characteristics of the ash.Unless abundant carbonates are present, coals with kaolinite-rich assemblages have a very refractory ash, while those rich in chlorite or montmorillonite have ash fusion temperatures between 1000 and 1300°C. Theinfluence of the minerals on coal preparation and coking properties is also brieflY discussed, as well as the potential of mineral matter studies in coal seam correlation.

Jan 1, 1978

Authors have been conducting research on autonomous loading operation by wheel loader. Autonomous loading cycles has been demonstrated with real size experimental model. In V shape loading operation, travelling between scooping point and dumping point is dominant factor for cycle time of the operation. The positions of scooping point and dumping point changes with advancing the operation. In the developed system, path planning is performed at the beginning of every cycle. The path is formed by combination of curve and straight path elements. During travelling on the planned path, path following control is applied on the loader to keep position error in narrow range. Positioning of the loader is based on dead reckoning with correction by global positioning system (GPS) data. In a process of path following control, control value for steering angle is determined based on position error in lateral direction. Proposed method of path planning and position control is installed and tested in the real size experimental model. The detail and results will be described in the paper.

Dec 6, 2010

My speech this morning is not a technical one, rather I will aim to tell you about the New Zealand Aluminium Smelters Limited and how I see it fitting into the Western World aluminium scene.

Jan 1, 1983

A pyrite flotation concentrate assaying 0·065 oz/ton gold was investigated to determine the mode of occurrence of the gold. Ftom cyanidation and acid leaching experiments it was concluded that O· 02-0· 03 oz/ton goldwas in solid solution in pyrite and the balance of the gold was finely dispersed as grains throughout the pyrite.Autoradiography and electron-probe examination of possible areas in briquetted concentrate did not detect any grains of gold. Neutron irradiation and gamma spectrometry confirmed on 100 mg samples the fire assays obtained on 1 assay ton samples.Oxidation to hematite and reduction to magnetite at 600°C made practically the whole of the gold extractable by cyanide. This technique could be of major significance for gold ores which contain a substantial amount of "refractory" gold.

Jan 1, 1969

By S C. Dominy

The gravity recoverable gold (GRG) parameter reflects liberated gold or gold-dominated composite particles that can be recovered by gravity separation. Recoveries depend upon mineralogy, in situ particle size and the comminution and extraction method used. Any ore bearing >15 per cent of gold greater than 50 ¦m in size is likely to have a GRG component. The principal characterisation methodology applied is the three-stage GRG (3GRG) test, based on a 40 kg to 100 kg sample. An alternative is the single-stage GRG test (SGRG), which is generally based on a 20 kg sample. Experience has shown that GRG values can vary throughout an orebody, particularly within different grade and/or mineralogical domains. Test programs must consider sample frequency and mass. This study demonstrates the variability of GRG results based on different sample masses. Consecutive underground faces on a coarse-gold dominated quartz vein were sampled taking five different masses from each. Each sample was processed using a SGRG approach. Subsequently, each development round was batched through a small gravity production plant. The results show that the small samples understate the plant GRG and show inter-sample variability. Large samples show less variability and a SGRG closer to the plant GRG. A high SGRG broadly correlates to higher gold grades, more coarse gold and larger gold particles. These results are intuitively correct, but indicate the likely challenges of sampling for gold recovery in heterogeneous systems.CITATION:Dominy, S C, 2013. Variability of gravity recoverable gold values in relation to test sample size, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 293-302 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By D Blair, T Scutts, L Fergusson

This paper presents a waste rock treatment and rehabilitation program conducted at a metaliferous mine site in northern New South Wales from 2000–2013. It updates findings from 2005 for Program #1 (which examined acidity, leachable metals and tree growth in a control and three treated areas of waste rock) and includes new results for Program #2 (which examined acidity, plant uptake of metals and trace elements and tree growth in a control and four treated areas compared to undisturbed background levels) and Program?#3 (which examined the treatment and revegetation of submerged mine tailings and an exposed tailings beach).Program #1 showed low soil pH in the control area remained unchanged from years 1–14, and soil pH in the limed and capped areas was initially increased but fell back to starting levels within 12 months and remained low for 14 years. In contrast, soil pH in the Terra B area resulted in soil high pH immediately after treatment and increased in years six and 14 without further treatment. Tree height and density in 2005 and again in 2013 indicated acidity in the control, limed and capped areas suppressed tree height and density; however, in the Terra B area, revegetation in 2013 was comparable to undisturbed forest. Outcomes in the control, biosolids and three Terra B areas in Program #2 were similar to those observed in Program #1.Program #3 showed the submerged and exposed tailings initially had low pH and high concentrations of total and leachable metals before treatment, but these became non-leachable after treatment with Terra B. Revegetation was achieved on the tailings beach, with almost uniform colonisation of bulrush and common reed, along with bottlebrush and golden wattle; a variety of reptiles have also been observed on the revegetated tailings beach, along with migrating ducks, spoonbills and grebes.CITATION:Fergusson, L, Blair, D and Scutts, T, ?2014. Treatment and rehabilitation of acidic waste rock and tailings – a 14-year case study, in Proceedings Life-of-Mine 2014 , pp 247–260 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By P M. Hancock

The West Coast contains one of the world's giant placer gold deposits with production since the 1860s totalling some six million ounces (present day value NZ$ 3.6 billion). The deposits have been worked variously by hand, ground sluicing, hydraulicking and/or elevating, blocking out, deep leading and bucketline dredging. Since the sharp gold price rise of 1979 - 1980 gold production has increased steadily (in spite of the closure of the Kaniere dredge) to some 30 000 ounces (933 kg) in 1984. Production is primarily from some 100 medium scale mining, operations treating 50 - 200 000 m3 of auriferous late Pleistocene fluvial gravels year. In spite of their economic value the deposits remain only poorly investigated and many fundamental questions relating to the origin and formation of the deposits remain unanswered. This paper attempts to describe the geology of the deposits and outline a genetic model for their formation, and then discusses some of the economic aspects and current limitations and opportunities of the growing alluvial gold mining industry of the region.

Jan 1, 1985

IN December, 1905, a Forwood down-wheeler grinding pan (5 ft dialmter), and similar in design to those in use on the Kalgoorlie goldfields, was installed for experimental work in connection with fine grinding jig tailings.The galena remaining in this product is very finely (closely) mechanically disseminated throughout the blende and gangue, rendering fine crushing imperative for its liberation. A reswne of the milling process in vogue at the old mill will enable the series of operations to be more closely followed. The ore at the South Mine assays, on the average-lead...

Jan 1, 1909

Orebodies are defined in economic terms in that they must satisfy conditions determined by costs of mining, extraction and marketing before being so described. Despite this they have an essential chemical character as specialized products resulting from geochemical differentiation, and it is surprising that so little basic geochemical research has been carried out with respect to ore occurrence and that prospecting methods based on geochemical principles are not more widely applied.Many exploration geologists associate geochemistry with analytical techniques applied to the detection of dispersed traces of metals from actual orebodies. Geochemical research, applied to economic geology, goes far beyond this limited field and the purpose of this paper is to discuss aspects of such research and its use in formulating exploration principles.THE GEOCHEMICAL BACKGROUND TO MINERAL OCCURRENCE AND EXPLORATIONThe three aspects of economic mineral deposits to which geochemical research can be of use in determining ore guides are genesis, control of deposition and mode of dispersion from orebodies after emplacement. Prospecting for mineral deposits is primarily based on theories of ore occurrence which deal with the genetic and depositional influences controlling localization of ore. There are many such theories and they will not be discussed here as they have been adequately reviewed in geological publications. Some are based on differing argument concerning the same empirically observed associations of ore. In this respect it is perhaps fortunate that they are not always mutually exclusive as regards the...

Jan 1, 1960

Removal of Arsenic in Fluorite Ore by Simultaneous Grinding-Leaching with NaHS Generally speaking, a high-grade fluorite ore is converted into hydrogen fluoride (HF), which is essential for the semiconductor manufacturing. With the continuous depletion of resources, novel technologies for processing low-grade fluorite ores are urgently needed, in order to lower the arsenic concentration to less than 100 mg/kg. In this study, a low-grade fluorite ore was upgraded by removing arsenic, which is difficult to remove by conventional method. The mechano-chemical leaching of fluorite ore (i.e. the sample was ground in presence of NaHS, using a beads mill) was carried out to investigate the removal of arsenic from the low-grade fluorite. Experimental results showed that the arsenic concentration was reduced to 73.2 mg/kg.

Sep 13, 2010

Recent literature is reviewed with emphasis on the design and scale up of mixers. Most important aspects of mixing have resulted from the study of Newtonian fluids and only a minor attempt has been made to extend the work to non-Newtonian materials.The rheology of non-Newtonian materials is outlined and the typical behaviour of mineral slurries is indicated.The importance of flow velocity, flow pattern, and fluid turbulence is discussed with relation to suspension of solids and rate of reaction.Data on experimental leaching of ore from Mary Kathleen, Queensland, show the effect of different mixing impellers.In conclusion, factors involved in the selection of a mixer are presented with emphasis on economic appraisal after pilot experimentation.INTRODUCTIONThe subject of mixing has attracted considerable attention during recent years, but relatively little work has been undertaken for the study of non-Newtonian materials. Most work has been restricted to Newtonian fluids because there are less inconsistencies in such study.Mixing, by definition, implies blending or combining, and ranges from gentle mixing which blends the contents of a large tank in 24 hours to violent mixing which completely homogenises the contents of a tank within seconds. Metzner and Otto (1957) have pointed out the present lack of knowledge on the degree (or quality) of mixing. Apart from this fact the design of mixers for Newtonian materials would seem to be reasonably certain.Both capital and operating costs rise rapidly with increasing mixer size. Therefore the design, or selection, of a mixer is a matter for economic consideration in the overall aspect of plant design and operation.

Jan 1, 1961

By W J. Rankin

A study was carried out to compare the environmental impacts of a number of process routes for lead and zinc metal production from sulphide ores using Life Cycle Assessment methodology and based on average industry data derived from the literature. The processes investigated were:blast furnace production of lead; Imperial Smelting Process for lead and zinc production; and electrowinning of zinc with the mining and mineral processing stages common to all three routes. The effect of a number of process variables, namely ore grade, fuel source for electricity generation and efficiency of generation, on the environmental impacts was also examined. The environmental impact categories considered in the study were:total (or full cycle) energy consumption; Global Warming Potential (GWP); and Acidification Potential (AP). The results of the study show that when produced separately, zinc production is more than twice as energy intensive as lead production (viz 48 and 20 MJ/kg respectively), however when produced jointly by the Imperial Smelting process, the energy intensity of the two metals is not all that dissimilar (viz 36 and 32 MJ/kg respectively). The metal production and refining stage was found to make the greatest contribution to the overall environmental impacts for all three processes. The study also highlighted the importance of taking a life cycle approach when comparing the environmental impacts of different processes.

Jan 1, 2002

A detailed study of the capital investment and production cost for copper electrowinning plants shows that significant savings in both can be achieved by increasing the current density. From the economic analysis it is determined that the optimum current density which will result in lowest capital investment and lowest operating cost is between 60 A/sq. ft. and 70 A/sq. ft., or at least three times as high as the Conventionally employed current density. The specific investment, expressed as $/ton-year, is found to be a function of both the current density and plant capacity and has a minimum value at the optimum current density. Empirical equations are developed for the purpose of estimating the capital investment and operating cost for plants of any production capacity operating at any current density.

Jan 1, 1972

A field method combining solvent extraction and paper partition chromatography permits a simple and rapid semiquantitative estimation of gold in siliceous, argillaceous and sulphide ores. The method will facilitate the eyaluation of prospect samples in which the gold is too fine for separation by panning.Ethyl alcohol-hydrobromic acid mixtures are suitable for chromatographic development of the gold complex, and give clear reproducible definition of the gold zone. Substitution of commercial "methylated spirits" for the ethyl alcohol gives equally good definition, improving the potential of the method for field use.A batch of six samples in the range of 0·5 to 5·0 dwt/ton can be completed in two hours. The range may be extended by simple modification to higher or lower values.INTRODUCTIONIn a chromatographic method described previously (Lever 1958, Nevill and Lever 1959), gold from a standard volume of ore clamped between -plate glass was extracted by aqua regia on to the paper. After cautious drying the chromatogram was developed by an ethyl acetate-nitric acid-water mixture and gold was identified by spraying with stannous chloride solution. Sensitivity of the method in the low range was poor. The brown line obtained in the 1-3 dw/j ton range, caused by movement of gold in the reduced form, was not considered to be a satisfactory confirmation of the presence of gold. It was felt that the method would be improved by using a more elegant extraction and applying developing conditions which would produce a well defined purple line at all gold values. Iron was a limiting factor, and a method of eliminating its interference was needed.The method now developed overcomes these shortcomings, and gives a reliable result with a purple line for assay values of 0·5 dwtjton and over. Gold is dissolved from an...

Jan 1, 1964

WHEN mining and treatment first started at Broken Hill only oxidised ores were available. These ores were rich in silver and lead-the silver mainly existing as chloride and the lead as carbonate.Treatment processes aimed mainly at the recovery of silver, lead being regarded as a by-product, and its recovery, except in so far as it affected silver recovery, was of minor importance.The first ore mined was carted to Terowie and thence railed to Melbourne, being smelted by the Intercolonial Smelting and Refining Co., of Spotswood.The first parcel (50 tons) returned £7442, or £148 16s. per ton to the Broken Hill Proprietary Company.The second parcel of 1053 tons, smelted at the Day Dream smelter, returned 132,142 oz. of silver, but no record is available as to its lead content.These results obtained from two parcels showed that by smelting the ore a handsome profit could be obtained, and Mr. La Monte was engaged to erect two 30-ton Nevada water jacket blast furnaces on Block 13. These furnaces were placed in charge of Mr. P...

Jan 1, 1928

The area around Big Bell was actively explored and sporadically mined for gold from 1904 onwards. The lease was named Big Bell in 1913. The property became established as a major mining centre with the development of the Big Bell underground mine in 1936. Mining operations commenced in late 1937 and ceased in January 1955, after milling 5.56 million tonnes of ore and producing nearly 21 tonnes of gold. In 1969 Australian Consolidated Minerals Ltd (A.C.M.) acquired the deposit then explored it alone and in joint venture until the current joint venture agreement with a subsidiary of Placer Pacific Limited (PPL) was negotiated in 1984. Following exploration and evaluation of near surface mineralisation, and a reassessment of the remnant pillars underground, the concept of a large open pit in conjunction with an underground mine evolved. The feasibility study was completed in October 1987, and the decision to go ahead was formally announced on 2nd December 1987. Placer Dome Technical Services Ltd were contracted to be the Project Managers, commencing construction on site early in January 1988 and handing the plant over to the operators 13 months later. The capital cost of the project at handover was estimated to be $133 million. The operating team commenced pre-production stripping of the open pit on 1st May 1988. By 31st January 1989 almost 16.0 million tonnes had been stripped and 350,000 tonnes of ore stockpiled.

Jan 1, 1989

By P McCarthy

"This paper is based on 30 years of involvement in feasibility studies as a participant, study manager and the leader of a firm that provides study components and overall study management. The following topics are discussed:the purpose of feasibility studiesaligning the goals of the study team with those of the ownerthe difference between optimisation and designhow the types and levels of studies affect the organisation of the studythe relative merits of various management structures and contractual arrangementssetting scopes of work and tendering the work outthe selection of a study manager and the study management teamcommunications within the study team and externallythe project management trianglemanaging scope changes and maintaining flexibility to respond to study findingsprogress paymentsmanaging a study crisisinnovation, risk aversion and bankabilityreporting the resultsthe dangers and benefits of value engineering.CITATION:McCarthy, P, 2016. Making studies work – organisation, communication and management, in Proceedings Project Evaluation 2016, pp 20–30 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

By C Chen, T Kan

The distribution ratio of Pb (LPb s/m) between three types of slags (FeOx–SiO2, CaO–FeOx and FeOx– CaO–SiO2) and molten copper after equilibrium was measured at 1300°C and oxygen partial pressure (pO2) of 10-10–10-6 atm. Results showed that for FeOx–SiO2 slag, the LPb s/m increased from 0.024 to 2.57 with pO2 increased from 10-10 to 10-6 atm. The LPb s/m with CaO–FeOx slag was lower than the FeOx–SiO2 slag at the same pO2, ranging between 0.015 and 0.53. Using the FeOx–CaO– SiO2 slag generated LPb s/m values (0.02–1.6) in between. The oxygen partial pressure in the investigated range had no obvious effect on the activity coefficient of PbO (γPbO) which was averagely 0.44, 1.70 and 0.71 for FeOx–SiO2, CaO–FeOx and FeOx–CaO–SiO2 slags, respectively. The increases in the (CaO+MgO)/SiO2 mass ratio of the FeOx–CaO–SiO2 slag induced the decrease in the LPb s/m and the increase in the γPbO value. However, the variation in the Fe/SiO2 mass ratio didn’t exert obvious effects.

Jun 19, 2024

Magnetite cenospheres 40-270 I/m in diameter have been found during the combustion of pyrite concentrate.Micrographs of the surface and internal structures are presented together with comment on the mechanism of forrnation.The similarity to cenospheres found during the combustion of pulverized fuel was noted and speculation raised to their contribution to the dust and fume load in flash smelters.

Jan 1, 1980

Pilot-Scale Study of Deep Cone Thickener for Phosphatic Clay Dewatering

Sep 13, 2010