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By S M. J Koleini, F Hedjazi

The purpose of this research was to study the calcination of lead-zinc flotation tailings from the Angouran lead and zinc flotation plant in Iran as a pre-concentration step prior to hydrometallurgical processing of the oxidised tailings. There is an abundance of these tailings in the Angouran region and making use of these tailings would help preserve national wealth and also reduce the serious problems of environmental pollution caused by the tailings. At the optimal conditions of calcining at 750 - 800¦C for 45 minutes, the sample showed a mass loss of about 19 per cent. Mineralogical analyses showed that under these conditions the carbonate minerals including smithsonite (ZnCO3), calcite (CaCO3) and dolomite (Ca Mg (CO3)2) decomposed to their respective oxides. Hemimorphite (Zn4Si2O7 (OH)2.H2O) converted into willemite (Zn2SiO4) and this transformation postponed the formation of silica gel in the leach solution. The grade of zinc increased from 22.20 per cent to 29 per cent. These mineralogical changes resulted in desirable reactions in the acid leach process.

Jan 1, 2004

By R W. Wilson, A R. Branch

For hot mines, the use of mechanical refrigeration machines has become an essential feature of ventilation and cooling systems. Over the last 30 years, considerable effort has been made in developing refrigeration strategies and equipment to provide cooling that is cost-effective, reliable and energy efficient. In addition to these general design requirements it is necessary to take into account project specific factors such as long term mine cooling needs, operating strategy and installation time. This paper examines a number of actual mine cooling installations which illustrate how these features have influenced the design and installations. For many mines, it is known how the cooling requirements will increase as the mine develops, based on the life of mine plan. The design of the cooling installation must cater for both short- and long-term needs. The initial installation (to meet short-term requirements) must form an integral part of the ultimate cooling installation and as additional equipment and refrigeration machines are installed, it is necessary to ensure that the system remains cost-effective, reliable and energy efficient at all stages. For many mines, refrigeration machines are installed on surface and either operated near-continuously, or for the summer months only. Different maintenance strategies and policies with regard to standby equipment are highlighted for three mine installations. In spite of developments in cooling strategy, the cost of providing refrigeration remains expensive and many mines delay the introduction of refrigeration, as long as possible. When it is finally accepted that refrigeration is absolutely necessary, it is frequently necessary to æfast trackÆ the installation. To minimise site erection time and meet installation deadlines, factory pre-assembly and standardised modular equipment are widely used.

Jan 1, 2005

The fire started in the development section from methane released into the mine through a roof-bolt hole. The date was 8 May 1998. The flames spread quickly as the coal was ignited. After eight hours the Safety Department decided to seal the vertical ventilation shafts and the slopes. The quality of coal in the Esmeralda Mine is very high quality, and Minerales Monclova (MIMOSA) decided to recover the facilities, however, the Esmeralda Mine coals have a very high gas content of 12 m3/t. Immediately after the mine was sealed, MIMOSA staff implemented a plan to monitor the gas levels underground and contacted specialists for assistance in bringing the mine back on-line. During the next 2.5 months, MIMOSA staff and the specialists observed and analysed the gas behaviour supported by a chromatograph. With the results of the observations and analyses, MIMOSA in consultation with the specialists developed a recovery plan based on flooding the area in which fire might have propagated and in which rekindling was highly probable. Those results were analysed by the command centre (Mexican engineers responsible for mine recovery). At the same time MIMOSA trained rescue teams which included miners who had no previous experience in mine recovery operations. By 20 August 1998, the mine command centre had re-opened the slopes seal. Using a æStep-by-StepÆ system, the rescue team began the recovery process by employing cross-cuts and using an auxiliary fan to establish the ventilation circuit. The MIMOSA team advanced into the mine as far as allowed by the water level and was able to recover the main fan. The official mine recovery date was 30 November 1998.

Jan 1, 2005

By Peng S. S

Measurement of pressure distribution under the base plate of the Hemscheidt 2-leg 800-ton shield was performed underground for two shifts using 12 pressure cells installed in two rows, one each under each split base plate. Pressure distribution was uneven depending on contact condition. In general the highest base pressure occurred at 1/3 of the base plate contact length from the rear edge. The resultant was near vertical, and the pressure under the tail side split base plate was always higher than the head side. For comparison, pressure distribution on the canopy and under the base plate was also measured under controlled conditions at the USBM's Mine Simulator Testing Facilities in Pittsburgh, PA. A total of 45 tests were conducted under several simulated contact conditions. The results showed that the actual contact area is highly dependent on the compliance of the immediate roof and floor due to the sloped canopy tip and a base lifting device under the base tip. The loading distribution tends to change in magnitude and profile as the leg pressure increases. The base lifting device exaggerates the high toe loading on the base plate characteristics of this type of shield support.

Jan 1, 1992

By Gang C, Changyi S, Liangde G

Geophysical and geochemical methods and techniques for gold exploration and their applications in China are summarised in the paper. Some case histories are also presented. The effect of prospecting for gold deposits using these methods is well illustrated through these examples.

Jan 1, 1997

This paper carries on from an earlier paper 'Cemented fill practice and research at Mount Isa' and reports further on the laboratory programme at Mount Isa to develop a cheap cem- ented fill using Company waste products. The practical economic significance of availability of cheap cementing agents is re- viewed, with the various alternative approaches available The basic approach adopted within this paper is that use of reactive pozzolans such as ground slags to replace a proportion of the Portland cement in the fill can make mining methods employing cemented fill more economic- ally competitive with other mining methods.

Jan 1, 1973

The addition of a thallous salt to the cyanide leach of a calcined pyritic concentrate causes a marked increase in the"rate of extraction of gold. This probably is due to the activation of passive gold by.th,e. thallous ions'.''Lea'd, bismuth, and mercury salts, which should produce ' a, similai effect, fail to do so. It is postulated that'this latter result, together with'the reprecipitation of silver at low cyanide levels, is due to the presence of soluble sulphide. The use of thallous salts to reduce leaching time is discussed briefly.

Jan 1, 1964

By Restarick C, Jowett A

A cylinder-cyclone system, fitted with a flow control valve between the cylinder and cyclone plus in some tests a variable cyclone spigot, has been used to achieve classifier separations at unusually coarse sizes relative to the diameter of the units used. The method has proved to be useful for low tonnage flows at low pulp density and variable feed rate. The system relies on use of a cylinder unit to reject excess water and fine particles, the amount rejected being adjusted by the flow control valve. The valve also adjusts flow rate and pulp density of feed to the cyclone unit, and can be adjusted to give a separation at a coarse particle size. The system has been used in connection with experiments on the pilot plant at Mount Isa, where a 76 mm system was used to classify feed to the lead secondary rougher circuit at sizes as coarse as 52 micrametres galena equivalent for split conditioning tests. Further tests have been carried out with quartz to assess the range of size separations Possible.

Jan 1, 1978

By Neill T. J, Howarth D. F, Malcolm J. McPhersqn

For many years Isa Mine has seen the need for a continuous mining machine which will economically cut hard rock. Tunnel borers are unsuitable due to the size and inflexibility of the machine and the shape of excavation mined. The design of roadheader type machines will not permit the use of the necessary cutting technology. in 1983 a joint project was undertaken by The Robbins Company and Mount Isa Mines Limited to develop and to trial a machine suitable for cutting hard rock in an operating mine. The project was based on the proven technology of raiseboring applied to horizontal development. The Mobile Miner was fabricated and trialled in a disused quarry in the U.S.A. during early 1984. Following these trials, the machine was transported to Mount Isa and commenced mining in September that year. The initial duty was to continue the development of a decline commenced by conventional mining for a conveyor system to serve the deeper southern areas of the 1100 copper orebody. This system will permit direct tipping of copper ore to a new crusher complex and conveying of the - crushed ore approximately 2 kilometres to the central hoisting shaft facilities. The Robbins Mobile Miner MM120-3001 uses a vertical rotating cutting wheel mounted on a horizontal swinging boom to excavate a nominally rectangular shaped heading. The cuttings are collected on an apron and conveyed back through the machine. The resulting excavation is smooth-walled with no blasting damage to the surrounding rock. This provides a safer working environment than does conventional drill and blast development mining. Ground support requirements are considerably reduced.

Jan 1, 1986

By A Romanel, M S. Kato, M P. Piermatei, P Artioli

"Brazil is the sixth worldwide producer of aluminum and Votorantim (Metals) has been operating three bauxite open pit mines in a particular way of working. In those the deposits occur on the top of hills, under forest, coffee, eucalyptus plantation or pasture area.The deposits are not large and normally mining takes an average of two months to be completed before starting the rehabilitation process, which demands a good strategy in mining planning to achieve the production goals.The benefit function developed to select feasible areas uses, beyond production costs, fees from the owner by using their area and rehabilitation cost. Both are based on land use and occupation field survey data. In this process each area with different land use receives a specific rehabilitation cost as input into a block model.Once the selection is made the mining schedule begins, taking into consideration the following premise: the orebody needs to be mined in a short period of time because during this time, the surface owners receive from Votorantim a compensation based on the expected profits from their plantation or pasture, plus royalties related to the ore amount existing in their area.Not all operations have waste dumps. Waste is pushed down by bulldozers to the lower part of the ore border. After loading and transporting ore, the waste is handled back to the mined area to fit the topography. With this step concluded, the mined area is directed to the environmental team who, alongside university partners, develop land reclamation to return them to their owners, eg in 2011, 110 ha were rehabilitated of which 29 per cent is native forest.Votorantim closes many mined areas a year and currently the entire mine planning considers this particular way of operation, making profit with minimum interference with the community and the environment.CITATION:Artioli, P, Kato, M S, Romanel, A and Piermatei, M P, 2012. Environmental variables at bauxite mine, in Proceedings Life-of-Mine 2012 , pp 171-178 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 10, 2012

By McClarnon D. J

This paper aims to provide the reader with an insight into the field of computer graphics and Virtual Reality (VR), and show how both have been applied to the general area of Free Steered Vehicle (FSV) operations underground. It first explains this developing computer technology and explains its advantages over existing CAD based solutions. This paper deals with the graphical applications and implications of building models within a computer's memory. It then continues to describe the problems with Free Steered Vehicle operations. The work already carried out in the field of VR is explained, and the production of a VR system addressing the problems with fitting cameras to aid the driver's field of view is detailed. Another possible use of VR is also explained - the concept of risk regions, demonstrating its uses in the examination of proposed operational methods. Examples of possible uses are given, and its potential advantages over existing methods discussed. A case study of a computer-generated video involved with the safety of operations of FSVs is also presented. This addresses the precautions that pedestrians should take to ensure safe working in areas where FSVs are operating. This paper then concludes with possible further applications for computer graphics and VR, and the on-going research into these two technologies.

Jan 1, 1995

By J-P Franzidis, E V. Manl, K Runge

Over recent years a number of techniques have been developed as part of the Australian Minerals Industries Research Association (AMIRA) P9 project to represent mathematically or measure directly subprocesses occurring in flotation cells. These include the determination of a:machine parameter (bubble surface area flux, Sb); froth parameter (froth recovery, Rf); entrainment and drainage parameters; and ore floatability parameter (Pi). A cost-effective methodology was developed for using these techniques to derive models of flotation circuits. This methodology was applied to derive a model of the flotation circuit at the Western Mining Corporation (WMC) Ltd Mt Keith Nickel Concentrator. The model was used to simulate a number of minor circuit flowsheet changes, the results of which are discussed in this paper. One year later, a second study of this plant was conducted. In this second study, data were collected while operating the plant in the flowsheet configurations that were simulated from the model developed from the first study. The results obtained from the second study showed reasonable agreement with the trends predicted from the first study model; discrepancies can be explained in terms of the model assumptions. This suggests that this simple circuit modelling methodology can be useful in assisting plant engineers to optimise flotation circuits.

Jan 1, 2000

By ZáWang, F Hungerford, T Ren

Operations in an underground drill site have to co-exist within the mineÆs ventilation and operational system. The space requirements of a drilling operation have to be adapted to the limitations provided in available site space, which is usually defined by standard mining operations and geotechnical influences. These limitations affect borehole design, equipment positioning in the site layout and possible interactions with mining equipment and services such as water and power supply.The ventilation requirements for drill sites and the means employed vary with depth of the site, space and likely presence of gas. All drilling operations provide a particular service for the mine and in each case, drilling must operate in a manner which controls all gas, water and cuttings returning from the borehole. The various standpiping systems employed have evolved under differing influences and must cater for conditions during and after the drilling operations.The influences that gas content, pressure and flow, rib stability, cleat direction, borehole length, potential water pressure and flow have on a mineÆs operation and ventilation systems have to be considered in the design of standpipe length, diameter and fittings. Past history has a strong influence on common practice while worst case effects of a possible in-hole event should be catered for.This paper describes the early drilling systems and their limitations in ventilation and gas management. The drill site dimensions and set-up are discussed in the context of roadway conditions, equipment layout, ventilation and logistics. The use of standpiping to control all returns from the borehole is illustrated by referring to likely scenarios in a drilling site to achieve the most effective sealed depth to accommodate the worst case possibility of intersecting high pressure gas or water during the drilling operation. Practices to allow gas drainage in the return airway of a panel are described.CITATION:Hungerford, F, Ren, T and Wang, Z, 2013. operational management of underground in-seam drilling sites, in Proceedings The Australian Mine Ventilation Conference , pp 43-48 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 1, 2013

The present stage of economic development of the Broken Hill lode, attained after 40 years of active exploitation, leaves little opportunity for the study of the zone of secondary sulphides.Little remains of the oxidised zone, and the observations of the secondary sulphides of copper and silver can rarely be made on specimens collected in situ. A few specimens containing secondary...

Jan 1, 1927

By P Cooper

Continuous improvement using six sigma methodologies commonly follows the DMAIC methodology of define, measure, analyse, improve and control. A key requirement in the use of this approach is to ensure that data is trusted, validated and contextual. In today’s production environments it is common to find disparate technology comprising the system architecture and highly customised interfaces between the various technology layers. This complexity often leads to inaccurate data presented at the operations management layer or worse, data that is not trusted. Identifying defects and making corrective actions cannot be efficiently carried out unless trusteddata can be easily obtained with a production context. It is also common to find that disparate systems of this nature present information in multiple ways and through multiple presentation systems. This paper discusses how the use of web-based technologies in an integrated technology stack can aid the accessibility, accuracy and trust of data used in decision-making and also how a unified visualisation environment can lead to greater operator efficiency.

Jul 11, 2011

Infrastructure is defined as all those parts of a mining development which are not directly concerned with mining and mineral processing. Infrastructure is of significant and growing importance in the overall develop- ment of mines, and the costs could be critical in determining the viability of a project. Prior to_project authorisation, feasibility studies are required, often in considerable detail, to determine costs with adequate reliability. It is necessary that the Engineer should be adequately briefed for carrying out these studies and that good liaison and communication with the Owner be maintained. Methods, costs, order of accuracy, and some special requirements of these studies are discussed. After project authorisation, rapid im- plementation of the proposals is generally desired. A suggested organisation and method for this implementation is presented and dis- cussed. Comments on fees, and particular points in the relationship between Owner and Consulting Engineer are given. Particular reference is made to differences in conditions compared with public works projects. Realistic attitudes of mind towards environmental matters, industrial relations, and contractual relationships are advocated.

Jan 1, 1974

Following the Moura No 2 Wardens Court of Inquiry and subsequent changes to the Queensland Mining Legislation there is a requirement in Queensland coal mines for: a person with the recognised competencies to be appointed at each underground coal mine to the position Ventilation Officer; and the person is directly responsible for the implementation of the mine ventilation system and for the establishment of effective standards of ventilation for the mine. The Regulations require that an underground mine must have principal hazard management plans that provide for at the least the following: emergency response, gas management, methane drainage, mine ventilation, spontaneous combustion, and strata control. Other than strata control all the plans require the ventilation officer to have roles and responsibilities to develop, control, monitor and undertake actions in relation to these plans.There are also another 34 Regulations that either directly or indirectly requires the Ventilation Officer to take actions.The purpose of this paper is to outline the information that the regulators look for in sealing plans and the actions the regulators will take if the sealing does not go to plan (TARPs being exceeded).

Jan 1, 2005

By D R. L Vedoy, L Botha, S P. Gumfekar, J B. P Soares

Most of the known in-place reserves of oil sands are found in Canada. These oil sands ores are mined using various processes to extract bitumen. The by-product slurry resulting from the extraction process, known as tailings, is discharged into tailings ponds. Fine kaolin clays are an important ingredient of the tailings because they remain suspended in water for many years. Current polymeric flocculation/dewatering technologies use acrylamide-based polymers such as polyacrylamide (PAM), but sediments produced using PAM-based flocculants hold considerable amounts of water due to the formation of loosely-packed flocs. Anionic polymers are better flocculants due to bridging and the charge-neutralisation mechanism. In this paper, we will compare the synthesis of two flocculants: thermosensitive, anionic flocculants and thermosensitive, hydrophobically modified anionic flocculants. The first flocculant is a copolymer of acrylic acid (AA) and N-isopropyl acrylamide (NIPAM), in which AA is the anionic monomer. The second flocculant is a copolymer of NIPAM, AA and the hydrophobic monomer N-tert-butyl acrylamide. We evaluated the dewatering efficiency of 2 wt per cent kaolin using both flocculants by comparing settling rates at different flocculant dosages, charge neutralisation ability and supernatant clarity. To better understand floc formation, we measured the floc size formed by both flocculants at different flocculant dosages. We propose that the hydrophobic monomer in the terpolymer flocculant helps expel water out of flocs, ultimately decreasing the water content in the sediments.CITATION:Gumfekar, S P, Vedoy, D R L, Botha, L and Soares, J B P, 2015. Thermosensitive, hydrophobically modified anionic flocculants for dewatering kaolin clays, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 45–50 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

Filter aids are currently used in many industries to increase filtrate clarity and filtration rates. In other industries filtration could be improved if accept- able filter aids could be obtained cheaply. The present paper describes a simple thermal process for making filter aids from coal, outlines the effects of coal properties and major operating variables, and discusses the properties of satisfactory products. Several possible variations in reactor design have been used experimentally, involving fluidized beds of carbon or inert material, reaction of the particles while entrained in air, and a combination of entrainment and fluidization. The limits imposed on product yields by the composition of the parent coal are considered in relation to a range of Australian coals and one New Zealand coal; and the effects of temperature, residence time, and reactant flow rates have been studied in relation to product yields and characteristics.

Jan 1, 1969

This paper describes operational experience with seam gas and spontaneous combustion management, gained during ten years of production history (1993 to 2003) in the Wynn seam at Dartbrook Coal mine. In addition, comparisons are made with more recent operational experience in the overlying Kayuga seam. Development and retreat longwall operations were undertaken in a 4.0 m thick working section of the Wynn seam, contained within the lower quarter of a circa 24 m thick mega seam, from 1993 until mining operations were relocated to the overlying Kayuga seam in 2004. Production from the first block of the Kayuga seam is currently underway with seam gas and spontaneous combustion management requirements being refined as further operational experience is gained. Seam gas management techniques, including pre-drainage with pressurised fracturing, surface to underground goaf drainage of a carbon dioxide rich seam gas and novel, high capacity ventilation circuits, were employed in the Wynn seam. Ventilation strategies included operating up to carbon dioxide STEL concentrations of 3.0 per cent in segregated return airways rather than being limited to the TWA-TLV concentration of 1.25 per cent. The spontaneous combustion experience at Dartbrook Coal has, to some degree, resulted in a change in the way the risk is managed in Australian coal mines. Values of carbon monoxide make and hydrogen concentrations are profoundly different from previously recommended management plan trigger levels and those used elsewhere in the industry. However, the detection of higher hydrocarbons together with rising oxygen depletion ratios and absolute hydrogen concentrations remain as indicators of advancing spontaneous combustion events. In this respect, experience gained in the Wynn seam was important in the initial management of the shallower Kayuga seam, an essentially greenfield site with no prior operational experience being available.

Jan 1, 2005