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By Williams C

A stibnite concentrate from Golden Spec (WA) was subjected to a series of tests involving high pressure cyanidation and pressure oxidation followed by conventional cyanidation. The concentrate, whose gold content was 18.1 g/t, yielded only eight per cent of the gold when leached directly by a standard 24-hour cyanidation test. The recovery was increased to only 15 per cent when pressure cyanided under the following conditions: ambient temperature, 2000 kPa oxygen pressure, two hour retention time and 30 per cent w/w solids pulp density. This poor response to pressure cyanidation emphasised the refractoriness of the material. Evidence of the fine distribution of the gold through the concentrate, from measurements of the particle sizing distribution and the gold analyses of the individual fractions, also suggested that this concentrate was highly refractory. Pressure oxidation of the concentrate at elevated temperatures followed by cyanidation yielded recoveries as high as 94 per cent. However a preoxidation treatment under the following conditions was necessary: 230¦C, 2000 kPa oxygen pressure for a period of four hours.

Jan 1, 1992

By Viney K. G, Molinia A. B

The Hellyer Pb-Zn-Ag orebody in western Tasmania was discovered in 1983, and mine production at a rate of 250 000 tonnes/yr commenced in 1987. Expansion to 1 million/yr will be completed by early 1989. Exploratory development to gain access to the orebody, to provide a 20 000 tonne bulk sample for pilot plant work and to confirm mining conditions and orebody continuity was undertaken using conventional drill and blast techniques and large diesel trackless equipment. A ventilation shaft was raisebored. Development in this phase totalled 2 815 m and provided a sound basis for rapid expansion of the mine.

Jan 1, 1988

By Chang TS, Suzuki K, Go H, Nakamura S, Kuwano Y

In 1979, a test operation of an experimental blast furnace was carried out to investigate the behavior of a sort of formed coke, which was used safely by 30% of total coke charge in No.2 B.F., Sakai works, NSC, in 1975". The Mashec-type formed coke of 60 x 60 x 40 mm in dimension was crushed and screened so that it had the same size range (1011,20 mm) as ordinary coke used in the base operation. Preceding to the operation, some experiments on the properties of the formed coke and the effects of crushing on them were performed.

Jan 1, 1981

By Martinick WG

In July 1986, Cable Sands (W.A.) Pty Ltd commenced mining for mineral sands at Minninup, approximately 16 km south of Bunbury, Western Australia.The area being mined is from the heel of the foredune to the rear of the hind-dune. The vegetation is mostly native vegetation with some old degraded pasture.The mining operation will be by suction cutter dredge, with continuous dredging, mineral separation and re-depositing of the sand.

Jan 1, 1986

Investigations into the flotation behaviour of single minerals, mineral mixtures and ores at the CSIRO Division of Mineral and Process Engineering have led to the development of sophisticated laboratory flotation testing equipment. Both routine and complicated flotation investigations can be conducted in a precise and reproducible manner using procedures and equipment that have been refined over many years of conducting careful batch flotation testwork. Several important advances in flotation research can be attributed to changes in testing procedure developed as a consequence of the availability of this equipment. The flotation cell and ancillary equipment is described and associated developments and techniques discussed.

Jan 1, 1992

By B P. Wrench, M J. Gowan, P J. Chapman

Embankment dams constructed mainly of sand or non-plastic fine soils are susceptible to liquefaction, particularly in high-rainfall, high-seismicity environments where there is sufficient water to saturate the materials and sufficient energy from an earthquake to cause liquefaction. This paper shows the process adopted to review the stability of an existing cross-valley, centreline-raised cyclone tailings sand embankment dam.The study showed that two-dimensional stability analyses did not sufficiently capture the potential for instability, overestimating the depth of the critical failure surface. Instead, three-dimensional modelling was required to provide a reasonable representation. Post-liquefaction stability analyses carried out using the three-dimensional model indicated an adequate factor of safety (FoS). The FoS under seismic conditions was still considered to be a concern based on pseudostatic analyses (but noting the limitations of the analysis method).Earthquake-induced settlements were estimated using an empirical approach based on case history records (Swaisgood, 2003). The post-earthquake event settlement was estimated to be in the order of 600 mm, which is considered to be acceptable for the embankment, taking account of the proposed long-term freeboard of more than 8 m under operating conditions and 2 m under the probable maximum flood condition.CITATION:Chapman, P J, Wrench, B P and Gowan, M J, 2015. Review of static and seismic stability of a cross-valley sand tailings embankment in a high-rainfall, high-seismicity setting, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 163–172 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By B Hall

The authors have undertaken many independent mine optimisation and operational improvement projects at Australian and international mining operations over the past decade. This work has provided an understanding of the underlying practices responsible for the good long-term performance of some operations, and the failure of others to achieve their objectives. Good long-term performance, and value creation can be achieved through a logical and rigorous process of identifying the optimal mine plan (æThe PlanÆ) that delivers the corporate goals, establishing appropriate performance measures that are aligned with these goals, and ongoing monitoring of compliance with the established targets to ensure the operation reliably achieves The Plan. A number of practical methods have been developed and implemented to assist mining operations deliver their corporate goals. This paper outlines some of these methods, providing some fundamental guidelines that will assist in the establishment, and reliable achievement of The Plan that delivers the corporate goals.

Jan 1, 2006

The provision of electrical power is an important consideration in project develop- ment. The first step to be taken in this area is to assess the power requirements of the project. The alternatives of taking a supply from a power authority or providing local generation can then be considered. This requires additional definition of the prob- able characteristics of the supply. The availability of authority power in Australia is limited by the extent of the state power grids. Recent developments now allow these grids to be extended and their load capacity increased to meet major load increases at less cost than was possible pre- viously. The options for local generation include diesel, gas turbine, steam, hydro, solar and wind, each having its particular performance characteristics and costs. The choice of fuel for diesel, gas turbine, and steam plant likewise involves consideration of a range of factors. The arrangements adopted for a number of development projects illustrate some of the aspects which influence the decisions on power supply.

Jan 1, 1986

THE following paper is a description of the plant and operations of the above company in their recovery and treatment of the quartz tailings deposited as final residues by the various mining companies. at Waihi, Karangahake, and Waitekauri into theOhinemuri River. During the past few years the silting of the Ohinemuri River has increased to such an extent as to cause considerable interest and discussion, and has lately been the subject of a most extensive inquiry by a Royal Commission, to consider the best means of dealing with what is generally spoken of as a public nuisance.Ever since the commencement of mining in this district, which was opened as a goldfield in 1875, the various mines operating have been discharging their tailings into this river, it having been proclaimed a sludge channel in 1895. Up to the year 1900 the quantity of quartz crushed was not large, probably not exceeding 500,000 tons; but since that date the annual tonnages discharged have increased enormously, and at the present time would total from 550,000 to 600,000 tons per year. Records show that up to the end of 1910 at least 5,000,000 tons have been crushed, for an actual yield of bullion considerably exceeding £10,000,000 in value, and all the valuable tailings from...

Jan 1, 1911

By Heape JM

Production from the Cattle Grid orebody commenced in August, 1974. This followed a recent discovery arising from an extensive exploration programme involving stratigraphic drilling, geochemistry and geophysics. Located some 4 km west of the original copper occurrences at Pernatty Lagoon the discovery was found to contain 4.6 million tonnes of ore averaging 2.4% copper. The ore is a "sandstone copper" type localised near the disconformity between two Precambrian (Adelaidean) stratigraphic units, the Pandurra Formation and the Whyalla Sandstone. The mineralisation roughly follows the interface between these units and occurs in fractures, vugs and along bedding planes. The mineralogical character of the ore is somewhat complex consisting of chalcocite and bornite, with associated chalcopyrite, sphalerite, pyrite and other less common sulphides. 1. Senior Geologist, Pacminex Pty. Limited, Sydney, N.S.W. 2. Mine Geologist, for Mt. Gunson Mines, Pacminex Pty. Limited, Mt. Gunson, S.A.

Jan 1, 1975

By Rao A. B, Rao V. D

Northeast of Brazil is situated in the polygon of drought. It covers some very important states like Bahia,Pernam- buco, Paraiba, Rio Grande do Norte, Cea- ra and Piaui , which have a potential for mineral production. Of them the main contributions that comes from Rio Grande do Nor to , Ceara and Paraiba are the scheelite and im portant quantities of granitic pegmatite mine- rals like tantalite-columbites, micas, beryls, precious stones, lithium minerals etc. On the other hand flourishing mineral economy in gold, tin, emeralds, chromium, lead, apatite is most- ly from Bahia; and potassium, salts, and petro- leum are from Sergipe, Alagoas and Bahia res; pectively. The most interesting aspect coninues to be the nucleus of the drought zone constituted of the Rio Grande do Norte, Paraiba and Ceara sta- tes.The first two authors have worked for twel- ve years in the region and have dedicated atten tion and time to two systems, namely skarns and granitic pegmatites. Their mineralogy,petrogra- phy, geochemistry, origin and economy is being worked upon from time to time to accompany the progress that is being achieved both in the sec tors of geology and economy. Besides, during the field campaigns, evidences have been sought to find the best guide horizons for mineralisa- tion and options for the location of target areas and prospection methods for scheelite, tantalites and other pegmatite minerals.

Jan 1, 1988

By A G. Dempster, B McKeown, S Saydam, J Coulton

The mining industry has undergone a profound and transformative shift in recent years, driven by the rapid advancement of emerging technologies such as automation, digitalisation, and electrification. These technological innovations have not only revolutionised operational efficiency and productivity but have also introduced an imperative need for new and innovative approaches to conducting mining activities. Specifically, the mines of the future face a new series of complex challenges when planning and developing greenfield or brownfield mining projects in the 21st century. These challenges include greater operational depths, higher seismicity levels, higher rock temperatures, increased environmental constraints and sustainability requirements, a higher degree of interoperability, lack of skilled workforce, and the need for sustainable and eco-friendly mining practices. Consequently, there is an essential need to formulate novel strategies and robust planning methodologies that re-evaluate how mines are planned, executed, and managed, from the early exploration stages to the post-mining era and the consequent uses of mine sites. This research focuses on identifying the factors influencing the implementation of modern technologies, such as autonomous machinery in mining operations, and their impact on mining method selection and longterm mine planning. The findings underscore a crucial need for a paradigm shift in how mines are planned and developed, going beyond mining method selection, which primarily focuses on geological and economic factors, and must evolve to incorporate the multifaceted implications of modern mining operations.

Sep 1, 2024

By M Wortley, A Cantarutti, T Ozkocak

The estimation of the grinding mill charge weight is vital to ensure its efficient performance. Mill underloading or overloading can cause losses through decreased production or unplanned down time. Metso Minerals Process Technology Asia Pacific and South America (MMPT) has developed two systems for measuring mill load. The first is an acoustic system (SmartEarÖ) and the second is an online model-based charge estimation system. The aim of both systems is to facilitate better operation of grinding mills. SmartEarÖ performs analysis on an audio signal from the mill and allows each different frequency component to be viewed, analysed and used in process control for load estimation. By isolating different frequencies, SmartEarÖ can give an estimate of mill load. The online dynamic mill model uses measurable mill parameters (such as power) to predict the current total load. Kalman filtering can also be utilised to further increase the accuracy of the model. Both of MetsoÆs systems have been installed at BHP BillitonÆs Cannington mine to measure the load within their autogenous (AG) mill. In this paper, the methods of mill load estimation are reviewed and compared to the bearing pressure reading, which is the current method used by Cannington to control mill load. The redundant estimates of mill load provide increased confidence and consequently more robust grinding operation under a wide range of conditions.

Jan 1, 2008

By J-S Zhang

In this paper, the author briefly introduces the resource characteristics of Chinese iron ore, as well as the present increasing market demand for iron concentrate. The SHP-3200 wet high-intensity magnetic separator (HIMS) is used to separate complicated weak-magnetic iron ores being composed of specularite, limonite and siderite in Jiuquan Iron and Steel (Group) Co Ltd. Some technologies have been used to improve SHP-3200 HIMS, including modifying the angle of magnetic polar from 90¦ to 83¦, cooling the exciting coils by oil instead of air, adding reverse-washing equipment to wash off magnetic particles and adjusting the tooth-space of the matrix from 5.0 mm to 3.5 mm or 2.5 mm to enhance the recovery of fine particles. It is still difficult to meet the requirement for recovering more difficultly separated iron and the demands for high-grade concentrate of iron. In order to improve the recovery of difficult-separated iron, the film-magnetic separation technique is applied into the HIMS and a new LY matrix is designed to form magnetic gradient vertically. A flowing-film feeder is also added and the feed mouth is modified to make a slurry flow formed in the form of film along the wall of matrix. The microstructure and dissemination character of the mineral particles is studied, and the specific susceptibility of the primary minerals is measured. Then the distributive characteristics of a magnetic field for the separator with film-magnetic technique and the motion of particles in the process of separation are all analysed. By introducing the film-magnetic separation technique to SHP-Φ700 HIMS, the recovery of iron can be raised from 69.45 per cent to 76.07 - 78.96 per cent with the similar grade of concentrates of iron. Such an increase of 9.51 per cent in the recovery also shows that it is feasible for such film-magnetic separation technique to be applied into HIMS.

Jan 1, 2005

By F A. Rosyid

Mineral resources are national assets which must be capitalised for national development. Those assets should be transferred into real economic capital and then into social capital to achieve national/regional prosperity. Successful development in the mining industry will depend on the correctness in determining the role of mining industries for regional development. Using the context of sustainable development, this paper will analyse the concept and process of mining industry development as an accelerator to achieve regional sustainable development, using the mining operations of PT Newmont Nusa Tenggara (PT NNT) in Batuhijau, Sumbawa Barat Regency as a case study. In the premining activity phase, Sumbawa Barat was dependent on the agricultural sector. Agriculture contributed around 40 per cent of the regional gross domestic product (GDP). Meanwhile, in the activity phase, mining became the sector with the biggest contribution to regional economy. From its operation in Batuhijau, PT NNT contributed around 70 per cent of the regional GDP per year since 2001. In year 2000, the GDP had increased 170 per cent from its figure in 1999. However, due to its depleting reserve, PT NNT will finish its activity in Batuhijau by year 2015. Consequently, the Government of Sumbawa Barat Regency must develop other sectors in the post-mining phase to sustain economic development. Based on location quotient (LQ) and input-output analyses, Sumbawa Barat should develop its priority sectors, ie agriculture, trading and hotel, services and construction to achieve sustainability after mining life. Development of these non-mineral sectors is expected to sustain economic growth in the region.

Jan 1, 2008

By Brent A. D, Olsen a. H, Mayfield P. L J, Grazier P. E

Concentrates produced from MnO2 and Fe203 ore fines have been targeted as potential feedstocks for direct metallurgical processing. Prereduction of pyrolusite-rich Mn02 sands to MnO has been investigated in batch and continuous experimental bubbling fluidised beds using CO-H2 reducing gas mixtures. This process has been found to produce a high grade feedstock suitable for smelting to ferroalloys or acid digestion for chemicals production. Similarly, production of highly metallised direct reduced iron (DRI) from hematite ore fines has also been investigated in batch bubbling bed reactors. Programs to characterise the reduction kinetics, fluidisation behaviour and defluidisation phenomena for both feedstocks are currently in progress to enable optimum process conditions to be determined.

Jan 1, 1995

By D Landriault, G W. Wilson, L Langetine and

Engineered soil covers are used for final closure options for both waste rock and tailings disposal facilities. Currently, cover construction requires excavation of appropriate cover material from a nearby site. If no suitable materials are available, the mine operation may have to ship appropriate materials long distances to the site before the construction of the cover can even begin. This has led to the proposal to engineer cover materials using existing waste materials from the mining operation. The paper presented here describes the results of a laboratory scale testing program to evaluate the potential for blending waste rock, smelter slag and tailings for the creation of a suitable cover material at a site in Canada. Tailings from the local mill, waste rock and slag were collected in the field and blended to create a material with an air entry value similar to the tailings and with physical strength similar to the waste rock. Testing indicated this mixed material could be blended at a consistency of a paste and was suitable for pumping. It can also be compacted to a high-density material. The preliminary results show that it may be possible to blend waste rock, slag and tailings into a material that can be utilised in the construction of a water retaining cover.

Jan 1, 2003

Mining companies in order to compete and succeed in being viable business propositions must look to the future and select mining methods which guarantee improved efficiency and productivity as well as lower costs.A mining company in adopting a method of mining must now select the equipment most compatible. To some mines compatible equipment may mean the use of drilling jumbos to replace hand held rock drills or the use of load haul dump units to replace scrapers. To other more mechanized mines compatible equipment may mean the use of raise borers and road heading machines. The right decision will be where equipment compliments method in such a way that the working environment is improved, productivity is maximized, cost if reduced and all profit opportunities are optimized. An example of such is where the use of improved mining techniques in underground operations may see cut off grades reduced. By selectively mining these lower grade orebodies, smaller operation's ore reserves improve and the capacity for continued growth is enhanced.

Jan 1, 1990

By Mark C. J

Since the commissioning of the BHAS Copper Plant in 1984 the copper electrowinning operations have not fully met expectations. During 1988, a laboratory scale electrowinning unit was constructed to enable an investigation of the effects of process parameters on copper cathode deposition and quality. The process parameters investigated were copper concentration, acid concentration, current density, electrolyte temperature, electrolyte flow, electrolyte impurities and electrolyte additives. The findings of this research program indicate that there is an optimum cathode deposition morphology which results in good quality copper deposits which have improved stripping characteristics. All of the process variables investigated influenced the copper deposition and therefore it was necessary to delineate a suitable operating envelope for the copper electrowinning. As a result new standard operating parameters in electrowinning have been implemented which has enabled the production of higher quality copper cathodes with improved stripping characteristics.

Jan 1, 1989

By R Williams, P Kohout, J Comins

The Northside Storage Tunnel (NST) is the largest tunnelling project ever undertaken in Sydney. The tunnel extends deep underground from the western bank of the Lane Cove river to the North Head sewage treatment plant (STP), with a branch tunnel from Scotts Creek connecting to the main tunnel under Tunks Park. The aim of the tunnel is to intercept wet weather overflows from four key points along the northernsuburbs ocean outfall sewer (NSOOS) and provide short-term storage and transfer of sewage to NorthHead STP for treatment prior to discharge to the ocean through the deep ocean outfall. The project was an ambitious undertaking by an alliance between the client Sydney WaterCorporationand the engineering firms of Montgomery Watson, Connell Wagner and Transfield to design andconstruct approximately 20 kilometres of tunnel, tunnel declines and shafts in just over three years. In order to achieve this tight timeframe construction of the NST has been undertaken simultaneously at seven construction sites located across the northern suburbs of Sydney. As with most tunnelling operations, tunnel boring machines (TBMÆs) and roadheaders dominated the excavation activities. Tunks Park and North Head STP are the major tunnelling sites. An access decline was excavated using roadheaders at both of these sites to facilitate tunnelling using TBMÆs. Three TBMÆs 3.8 m, 6.0 m and 6.3 m diameter) were launched from Tunks Park and one TBM (6.5 m diameter) was launched from North Head. At the overflow interception sites of Scotts Creek, Lane Cove River and Quakers Hat Bay two vertical shafts known as drop and access/ventilation shafts were constructed. These shafts would provide the linkage between the existing sewer and the tunnel. As their names suggest the drop shaft would convey the wet weather sewage overflows to the tunnel while the access/ventilation shaft would provide access during dry weather and ventilation during a filling event. The fourth overflow site of Tunks Park would use the tunnel decline as its link to the tunnel. Originally these shafts were to be excavated using the raise bore method. This technique however, is entirely dependent on the TBMÆs reaching the shaft locations at the specified time. This was not the case at two of the three shaft excavation locations and top down methods of excavation such as, a percussive cone fracturing (PCF), blind bore, mechanical excavation and drill and blast were investigated to ensure the project met its completion schedule. Traditionally project decisions are dominated by cost and schedule objectives. The contractual arrangement of the Alliance however, required that the objectives of safety, community and environment also be considered in any decision making process. Thus each of these top down methods of excavation were assessed against these five objectives. On considering all of these factors the use of explosives was considered to be the superior technique.

Jan 1, 2001