Search Documents

This paper describes the principle of cut-and-break rock excavation, in which rock is first undercut, and the undercut material is subsequently broken free by a wedging action. The current work on cut-and-break using the large rock cutting test rig at the Centre for Mining Technology and Equipment (CMTE) is outlined, and suggestions are made as to the potential advantages of cut-and-break roadheading, particularly in excavating short tunnels in hard rock in an urban environment.

Jan 1, 1993

By McCarthy P. L

With production at Olympic Dam scheduled to commence in June 1988, it has been necessary to install a complete underground ore handling system capable of removing two million tonnes of material annually from the mine. The system comprises mucking from stope drawpoints, truck haulage to underground storage, primary crushing, conveying and hoisting. On the surface, material is conveyed to stockpiles at the Metallurgical Plant. Mining of the numerous special excavations within the system was incorporated into the mine's ongoing development program prior to the underground construction phase. Utilisation of a decline from the surface enabled versatile construction equipment to operate at the underground sites as well as simplifying the transportation and delivery of construction Materials.

Jan 1, 1988

The concentrating plant of the Broken Hill South Limited was described in Proceedings No. 44, Australasian Institute Mining and Metallurgy, December, 1921, by Wainwright and Read. It was erected on the present site in 1907 and 1908.From that date, the plant has undergone various alterations consistent with metallurgical improvements. By 1925, the timber work of the gravity secti"on had seriously deteriorated, so much so, that, when the machinery was working, the floors and supports vibrated badly, causing heavy maintenance costs.In 1928, it was decided to erect a new gravity-treatment section, to be followed later by a new flotation section.

Jan 1, 1932

Better quality at lower cost is today's formula for remaining competitive in a world market. For an integrated steel company, high quality low cost steel production must originate before the blast furnace. In 1979, when U.S. Steel initiated a Quality Management Program throughout its steelmaking operations, efforts began at the coal, ore and flux mines. The objective was to improve the quality and reduce the variability of the critical parameters for steelmaking raw materials, to get the blast furnaces, and subsequently the melt shops, under optimum control. The general details of U.S. Steel's Quality Management Program are discussed and how it was used to promote the desired improvements in steelmaking raw materials. Some of the outstanding results obtained by the cooperative efforts between the mines and the steel plants are reported. The lessons learned by U.S. Steel were through upgrading existing operations and facilities. These principles should now be applied to new projects and the benefits of good quality management should commence from the time new projects are Commissioned.

Jan 1, 1986

Felspar occurs in association with quartz in the Broken Hill lode pegmatites and is brilliant green, greenish white, and white in colour. The pegmatites occur mainly in the walls in sporadic patches, parallel to the general dip of the ore deposit. The occurrences are of no economic value.Deposits of marketable felspar occur in pegmatite in a number of localities around Broken Hill, New South Wales.The majority of these are in the form of an irregular outcrop, usually of tapering length and depth. The maximum depth of any deposit yet worked in the district is about 40 ft. The felspar is occasionally contaminated by "blows" of quartz, mica and beryl, but the two latter are profitably marketable when separated.Felspars vary in colour from pink, through grey to snow white, and the colour is not indicative of the mineral content. The largest deposit at present being worked is the Egebeck quarry, about 14 miles south of Cockburn. It is a prominent outcrop, roughly circular and about 150 ft. in diameter, covered by one to three feet of overburden.The felspar is mainly massive, but contains some cleavage planes at approximately 90°. Intrusions of quartz and mica occur in patches, but the deposit appears likely to improve in size, regularity and quality below the present working floor.COMMERCIAL USES.Commercial felspars are mainly used in the ceramic industry, for which a high-grade potash felspar is required.The dental industry requires limited amounts of soda felspar with a very low Fe20s content. The poorer grades...

Jan 1, 1946

The difficulty in screening of ores when the moisture contents reach certain critical levels has resulted in mining circuits using wet processes for screening. While this has been acceptable in past years it is no longer acceptable in certain countries and where the mining company is looking to reduce its impact on the surrounding environment.   Various mining companies have been looking at ways to remove the need of using water, with all its inherent drawbacks and to be able to produce its desired products in a dry process.   This would have the benefits of less environmental impact and cost, (due to not requiring wet processing equipment), less power consumption (reduced equipment needed), no corrosion issues, no contaminated waste waters and reduced maintenance activities.   Until recently this has proven elusive or with technical restrictions with current available acceptable technologies for high capacity plants.   One major mining company began seriously exploring ways to overcome this dilemma so that they did not replicate their current ways of operating for their new expansion plans.   They partnered with Metso Minerals to undertake extensive groundbreaking laboratory test work and provide potential solutions as to how to solve this. The laboratory test work proved interesting enough to design, manufacture and test on the actual mining site a prototype screening machine in the circuit.   This break through in screening technology reduces the environmental impact on the area in which the mine is located by: eliminating the storage and use of water, reduction in energy consumption due to having no pumps in the plant, reduction in plant costs and the upstream affects on the environment process used to manufacture and ship the materials the plant structure is built from, and no large tailings dams to take up land space and affect the environment through groundwater/ water table contamination and the negative effects on animals and ecosystems Laboratory test were conducted and a full size machine was installed at the plant site along side conventional machines. The screen size (2.4 m wide x 6.1 long double deck) was determined by the size of screens currently in operation at the mine. The parameters that were explored were: types of screen surface (polyurethane, woven wire etc), types of screen motion (linear, circular or elliptical), angle of motion ( 40,45,55,60 degrees etc), and throw (amplitude), speed and 'g' force.

Jun 1, 2010

By Maconochie A. P

The copper-gold orebodies of the Ok Tedi project and located in an area of climatic and topographic extremes, where both the landforms and the rocks from which they have developed are so young that it may be said that geological and engineering processes are coincident.

Jan 1, 1990

Maintaining and improving the economics of open pit mining in the future requires understanding of the characteristics of open pit mining that are different to other mining or business activities, designing mines in the first place to be less susceptible to changes in these important characteristics, and adopting strategies which yield reliable returns despite unforeseen change. Planning and production personnel require guidelines and performance standards that are based on sound economics not solely on production criteria. The guidelines adopted for long-term implementation must assume a declining price for mineral products along with declining real costs, with research efforts directed at development of both evolutionary and revolutionary ideas aimed at implementation. Decision-making must focus on risk and probability criteria rather than just simple return-on-investment criteria, and the approach for management of personnel must support the higher level of communication essential for fast decision-making in the new environment of continual change.

Jan 1, 1992

By B Dunstan, F Wirfiyata

PT Newmont Nusa Tenggara (PTNNT) operates the Batu Hijau copper and gold mine and process plant on the island of Sumbawa, Nusa Tenggara (Barat)  NTB, Indonesia. The plant consists of a nominal capacity 120 000 t/d conventional semi-autogenous ball milling crushing (SABC) circuit followed by sulfide flotation to produce a bulk copper concentrate for sale. Process control is effected by a plant wide distributed control system that overlays an extensive integrated programable logic controller (PLC) framework. The system is enhanced by a supervisory expert control system.Since plant commissioning in September 1999, over US$4 million has been expended as part of a systematic continuous improvement approach to optimise plant control performance. Works completed to date include: redesign and upgrade of architecture of the control system to ensure long-term system reliability, security and upgradeability and to provide a suitable platform for advanced control; integration of supervisory and advanced control tools, techniques and instrumentation; and implementation of sound network communication and plant data reporting tools. This paper outlines the evolution of process control and associated systems and tools that contribute to successful operation and ongoing performance optimisation at Batu Hijau.

Jan 1, 2009

By R Buerger, D Barrett, P Hodkiewicz

The Emily Ann nickel mine is owned and operated by LionOre Mining International Ltd. The deposit was discovered during 1997 and is blind, concealed beneath 25 m of transported cover and a further 100 m of unmineralised Archaean felsic rocks. Nickel sulfide mineralisation is hosted predominantly in strongly deformed, altered and metamorphosed Archaean komatiitic ultramafic rocks. Subordinate felsic-hosted, remobilised mineralisation is also present. Mining of ore commenced during late-2001. Since the early days of exploration drilling, through feasibility delineation drilling and subsequent mining, a geological model involving thrusting and folding of a komatiitic-hosted nickel sulfide deposit has been an evolving theme. Development of appropriate mine geology procedures, including detailed mapping, significantly increased the confidence of mine-site geology and engineering staff in the geological model and improved operational efficiencies during start-up. This also allowed the engineering and mining team to develop a tolerance for the large fluctuations in daily production grade, with an understanding that budgeted production targets, on a level-by-level basis, were achievable. This paper describes the development of the current interpretation of the deposit and emphasises the importance of a sound understanding of deposit geology. The direct benefits at Emily Ann included improvements in drill targeting, resource estimation and mine planning.

Jan 1, 2003

At 11 p.m. on Tuesday, 24th July 1979, an explosion of methane gas in a three heading development panel at Appin Colliery resulted in the deaths of fourteen men. The explosion followed after or was asso- ciated with a changeover of the ventilation to achieve a central intake between two returns. Investigation by Inspectors was followed by separate Judicial and Coronial Inquiries. Investigational information aimed at understanding the circumstances of the ex- plosion was prepared for the Inquiries. Recommendations following the Judicial Inquiry have been adopted by the Department of Mineral Resources.

Jan 1, 1981

By L Gladysiewicz

This paper deals with the current situation in the mining industry in Poland. An overview of typical transport systems working in the different branches of mining is provided. The transport systems currently used in lignite mining, particularly in the Belchat=w mine û the largest brown coal mine in Poland, and those operating in copper mines are described in detail. New designs of belt conveyors used in underground hard coal and copper mining are presented.

Jan 1, 2003

By R L. Brathwaite, R Carver

The REGCHEM (Regional Exploration Geochemistry) database of open file mining company data, managed by GNS Science, has recently been upgraded with the compilation of additional data, especially for the Otago region (see http://maps.gns.cri.nz/website/minmap). In June 2007, data compiled for the Otago region included more than 2000 stream sediment samples from 19 surveys, more than 800 BLEG (bulk leach extractible gold) samples from 12 surveys and a few pan concentrate samples. The stream sediment samples were typically analysed for Au and As, and in many cases for other elements including Cu, Pb, Zn, Sb, W and Mo. The BLEG samples were analysed for Au and in some cases also for As. The main exploration target was mesothermal gold deposits in the Otago Schist, although one survey of the Otago Peninsula targeted potential gold deposits associated with the Dunedin volcanic complex. Geochemically, the mesothermal gold deposits are characterised by anomalous As and Au, with some also characterised by anomalous W and Sb, and these four elements are the best pathfinders in stream sediment geochemical surveys. The introduction of lower detection limits in Au analyses in the more recent stream sediment surveys and in the BLEG surveys enables the use of this element as the primary pathfinder for mesothermal gold deposits.

Jan 1, 2007

Stressed steel cables, similar to those used in pre-stressed concrete, have been used for rock mass reinforcement, in civil engineering, for many years. This type of reinforcement has been attempted for open pit wall support, on several occasions, but has never gained wide acceptance as a practical approach because of high cost and complexity of installation in a mining environment. On the other hand, untensioned, fully grouted cable dowels (cable bolts) have gained wide acceptance for ground support in underground mining and it is perhaps surprising that this technique has not been used to a greater degree in open pit mining. The first systematic application of this technique in Australia was at the Mary Kathleen uranium mine in 1976, where it was spectacularly successful in maintaining steep stable walls in a jointed rock mass with unfavourably dipping structures. Cable bolting, and other techniques, are now being used to an increasing degree for wall support in both small and large open pits, for two basic applications: 1. stabilisation of potentially unstable sections of a wall, or 2. to allow steeper walls and reduce waste stripping volumes. In virtually every situation, wall rein- forcement has significant economic as well as technical advantages. The paper describes the development of the techniques, the mechanisms of wall support, the methods used, and discusses several case histories of its application to Australian open pit mines.

Jan 1, 1986

By I F. Wood

Planning for flooding and assessment of flood impacts are important requirements for mining projects, as they are also for other types of development. With more intense development and concern from the community, supported by government regulatory requirements, assessment of flood concerns and impacts has become of increasing importance. To ensure that flooding issues are fully understood and results presented in an appropriate format, advanced hydraulic analysis procedures have been developed and are beginning to be applied. These procedures must be rigorous in an engineering context but the results must also be readily understood by the community and government agencies. Advanced two-dimensional hydraulic modelling is becoming accepted as an important means of assessing flooding issues for mining projects. With presentation of results from hydraulic models with Geographic Information Systems (GIS), flood impacts can be analysed rigorously and presented clearly. This paper discusses the application of advanced hydraulic modelling in the planning and impact assessment of a major mining project located on a floodplain where there is extensive inundation. The analysis provides for both input to the planning of the project and for detailed assessment of potential impacts. This case study illustrates some important aspects of the application of hydraulic modelling using a two-dimensional modelling to a critical flood design.

Jan 1, 2003

By Henley S

The year 2000 is not very far ahead - only five years. It should not be hard to forecast what will happen between now and then, because the technologies that will be in practical use then should all be at least in embryo existence now. There has been a historical trend for the mining industry to work ever more difficult and ever more marginal deposits. There are clearly a few exceptions and major discoveries, but the industry is becoming heavily dependent, at both the exploration and the mining stages, on technological innovation to retain acceptable profit margins. With the new exploration and mining technologies come requirements for additional computing support. Computing technology further allows the potential integration of a wide variety of different types of data to help the explorationist to build and test exploration strategies, or to help the miner to design and schedule mining operations.

Jan 1, 1995

Supergene enrichment of ilmenite occurs through a complex series of reactions with initial oxidation and hydration followed by leaching and dehydration. Lateritization appears to be associated with the early phase of the supergene process and if ilmenite grains are encased in iron oxides no further alteration proceeds.

Jan 1, 1986

By K B. Barnard, M D. Urbani

A synergistic solvent extraction (SX) system for nickel and cobalt recovery using Versatic 10 and decyl-4-pyridinecarboxylate was tested with BHP Billiton pilot plant leach solution. Another synergistic SX system for cobalt and zinc recovery was successfully tested using Baja MiningÆs pilot plant leach solutions. Synergistic SX systems have also been developed to separate iron, zinc and copper from nickel and cobalt for Minara Resources and to separate manganese from magnesium and calcium in waste stream for HiTec Energy. The gypsum precipitation problem at the former Bulong operation could have been alleviated using a Versatic 10 and CLX50 synergistic SX system. These synergistic systems have shown high selectivity for target metals over impurity metals and would largely improve SX plant operation. Maintaining a æhealthyÆ organic is very important for efficient plant operation. Careful analysis of plant organic at CSIRO has been used as a tool to pre-empt and/or solve problems in operating circuits. Work performed to assist operators has included assessing plant organic solutions to highlight impurity build-up with time, assessing reagent stability under prescribed operating conditions, correlating organic composition with impurity transfer and crud analysis. An independent estimate has determined that work in this area by CSIRO has provided over $50 M in benefits to the industry.

Jan 1, 2005

The Broken Hill (BH) Block contains a wide variety of mineralization, with comrodities including Pb, Ag, Zn, W, Cu, Co and Sn. Much of the mineralization is stratigraphically controlled. Fe, Cu and Co-rich mineralization is dcminant in the Thackaringa Group; Pb, Ag, Zn and W is dcminant in the BH Group and Sn mineralization is present above the BH Group. Some mineralization occurs as concordant syngenetic deposits, but other types have been partly or completely remobilized by metamorphism, magmatic activity or hydrothermal fluids. Almost all of the non-syngenetic mineralization, including stratabound, vein and intrusive-related types, has formed from the "recycling" (remobilization and redeposition) of metals originally deposited with the sediments and volcanics of the Willyama Supergroup.

Jan 1, 1983

By Lin Bin, Qain Minggao, Qu Qundi, Yao Zhichang

This paper describes the application of a 89C52 chip microcomputer in hydraulic pressure information monitoring system of powered supports in a coal face, and the details of circuit and software of a monitoring system substation. Each substati

Jan 1, 1998