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By C P. Kramers

The need to provide a sufficient quality and quantity of backfill continues to increase in South Africa, particularly as related to the increasing depth of mining. More and more applications require well designed fill systems either as classified or cemented backfill, and in some applications even tailings/aggregate based backfills. The paper discusses developments in backfill technology in South Africa with special emphasis on reliable system designs and operations, particularly as related to the preparation and hydraulic transportation aspects. Approaches for the alleviation of previous problems associated with premature pipe failures in vertical shaft columns for the distribution of tailings based backfills are discussed. Resulting from CSIRÆs developmental work, reliable full-flow systems, which can operate at low system pressures, have become a common practice, provided that backfill flowrates and internal pipe sizes are well matched. This aspect is reviewed. With regard to the tailings/aggregate based backfills the paper reviews some of the results of comprehensive in situ monitoring and the development of such systems. It is shown that a thorough understanding of the effects of aggregate top size, fines content and slurry relative density is required in order to ensure the restartability of temporarily shut-down pipelines. Some innovative technologies for the comminution of development waste underground to yield aggregate products potentially suitable or hydraulic transportation and backfilling, are briefly discussed.

Jan 1, 1998

By J J. Cilliers, K Hadler

Froth structure and stability are known to play important roles in determining mineral flotation recovery and selectivity. However, measuring froth stability in a consistent manner remains a significant challenge, especially at an industrial scale. Following preliminary tests on a copper concentration plant, a quantitative dynamic stability measure is investigated in this study in order to extend the results over a wider range of conditions and on a different orebody. The technique is based on the Bikerman foam test and uses a non-overflowing froth column to quantify froth stability. Experiments were carried out using an automated version of the froth stability column under different operating conditions. Air flowrate was the key operating variable. Tests were reproduced on a single flotation cell of a Platinum Group Metals concentrator. The froth stability factor, , was measured for each operating condition, and compared with the air recovery in the cell, , which was measured using image analysis. The froth stability column results gave the same trends as image analysis. In particular the froth stability factor was found to be linearly related to the actual fraction of air overflowing the cell. The metallurgical results clearly indicated that changes in air flowrate result in variations in flotation performance that can be attributed to changes in froth stability. The results showed that high froth stability conditions occur at intermediate air flowrates, and result in improved flotation performance. It is found that the froth stability column is a simple, cost-effective and reliable method for quantifying froth stability, and for indicating changes in flotation performance.

Jan 1, 2005

Anyone who has driven backwards using only their rear view mirrors knows how difficult it is to avoid spinning the steering wheel the wrong way. So why run your mine that way? Traditionally Reconciliation has focused on the past performance of the mine. In this paper we make a case for Prognostication û the act of forecasting or predicting something in the future from present indications or signs. Reconciliation is a common activity carried out at most mines around the world. Countless geologists and engineers spend hours poised in front of spreadsheets diligently comparing how their resource/reserve model, grade control, and survey pick ups compare to what was actually produced. The result is usually a group of factors, which are applied to future estimates in an attempt to better predict how the operation may perform. Unfortunately, if the road ahead isnÆt the same as what you have just been down, youÆll be æoff-roadingÆ in no time! An alternative is to constantly collect and analyse key measurements that are used to calibrate critical estimates in an iterative process. When variations occur, they are analysed and corrective action is taken to ensure the estimates and measurements realign. In this way the estimates become forecasts and can then form the basis for decision making to ensure that what does happen in the future will match the plan or schedule. By automating this process, some mines have been able to be proactive on a daily basis in order to improve the overall performance of the operation. This paper outlines the key estimates and measurements used for reconciliation, details the characteristics of an automated web based information management system to facilitate the process and provides some insights about how mining operations might move beyond reconciliation.

Jan 1, 2003

By D C. S M, J Skudder, R F. Sandenbergh

Metallic sulfide minerals present in most gold ores, Morila gold ore included, often decompose under typical gold leaching conditions. The reactions and their products consume oxygen and sodium cyanide, consequently competing for oxygen and cyanide used in gold dissolution. The resultant effect is to reduce both the kinetics of gold dissolution and overall extraction efficiencies. The present paper discusses results obtained from plant data analysis and laboratory work investigating the problem of higher than expected consumption of sodium cyanide at Morila Mine Gold Plant. Cyanide consumption at the Morila Mine Gold Plant had been consistently running at 46 per cent higher than the expected value without any corresponding increase in gold recovery. In fact, plant data analysis showed an inverse relationship between cyanide consumption and grind, as well as cyanide consumption and gold recovery. Experimental and plant data analysis indicated that better control of the [CN-]/[O2] ratio is necessary for the efficient use of reagents and achievement of higher gold recoveries. Careful control of this ratio at a minimum of eight enabled the reduction of sodium cyanide consumption by 200 g/t, that is, from 650 g/t to 450 g/t. Coupling these experimental conditions with the addition of lead nitrate at 100 g/t improved the overall gold recovery to 93 per cent compared to the average plant recovery of 90.2 per cent over a six-month period. This improvement was also reflected in the leaching kinetics where 70 per cent gold extraction was achieved after four hours, as compared to 59 per cent in the absence of lead nitrate addition. Also of great importance is the fact that the combination of hydrogen peroxide and oxygen gave inferior performance relative to either of the two reagents used separately. This scenario presents an opportunity for excluding hydrogen peroxide, an expensive reagent, and focusing on improving the oxygen addition system to boost dissolved oxygen concentration in the plant.

Jan 1, 2007

Stope control information at the C.S.A. mine is obtained by diamond drilling inclined holes from within the stapes. Practical mining outlines are determined from complicated ore contours by a joint mining engineering and geological study. Production holes to achieve this outline are individually marked up and checked. Stope control also extends to selective mucking of ore mixtures for metallurgical reasons and to marginal ore and waste mixtures for economic reasons.

Jan 1, 1969

Saxonvale mine is a multi bench open pit coal mine developed to its Stage I capacity of 1.75 Mt/y of run of mine coal. Detailed engineering studies for the mine commenced in April 1980, approval to proceed with the development was received in July 1980 and first coal shipments were made in April 1982. The engineering and project management of the mine development was carried out by BHP Engineering. This paper outlines the design and site administration for the development and describes both the organisation structure and the control and administration procedures used by BHP Engineering to ensure that the project was Successful.

Jan 1, 1983

By P Radulovic, W Y. Lui

The Mount Isa Mines (MIM) copper concentrator at Mount Isa processes both chalcopyrite ore from the MIM underground mine and rotary holding furnace (RHF) slag from the MIM copper smelter. There have been numerous changes to the processing practices since commissioning this concentrator in 1973. Current management of the concentrator extends from grinding and flotation to concentrate handling (thickening and filtration) and tailings disposal (fill plants, tailings thickeners and process water systems).Predominant mill feed through the concentrator is chalcopyrite ore. RHF slag is processed when concentrator production exceeds mined ore production. The chalcopyrite circuit has two stages of grinding in parallel lines (Line 1 and Line 2). Each line has parallel preflotation and rougher banks, combining into a common scavenger/retreat circuit (including regrinding) and common cleaner circuit. RHF slag may be milled in parallel with chalcopyrite, utilising Line 2 flotation roughers and a Jameson cell cleaner. All final concentrate produced is combined and pumped to the concentrate handling plant. The concentrate is thickened, pre-fluxed and filtered in hyperbaric disc filters. Fluxing specification is set by the copper smelter, and filtered product transferred via conveyor belt to the smelter concentrate storage facility.Wet fill and paste fill plants utilise flotation final tailings as hydraulic or cemented hydraulic fill for stopes underground. Cement ratios and fill plant utilisation are varied depending on underground stope fill requirements. Tailings from the adjacent lead-zinc concentrator are also processed at wet fill. All tailings that are not utilised for backfill are pumped via wet fill to three parallel tailings thickeners. Thickener underflows are gravity fed to the tailings dams with thickener overflows recycled for site process water use. In addition to summarising historical operations, this paper will provide a detailed outline of more recent changes in the concentrator flotation circuit, equipment upgrades, reagent optimisation as well as product and process optimisation at the final concentrate handling and fill plants.CITATION:Lui, W Y and Radulovic, P, 2013. Mount Isa Mines copper concentrator - An insight into current and historical practice, in Proceedings MetPlant 2013 , pp 553-574 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By Corbett GJ

Epithermal gold-silver deposits occur in young volcanic terrains where post-mineral cover commonly impedes the search for mineralisation. At the Togi Project in Honshu, Japan, a complex mineralised system is largely covered by post mineral volcaniclastics. A combination of high resolution electrical resistivity surveying and detailed airphoto interpretation has, with close geological control, enabled synthesis of structural and alteration characteristics of the Togi geothermal system, in turn permitting ranking of the prospects for drill testing.

Jan 1, 1990

The inauguration of a geological department for the mines of North Broken Hill Limited necessitated the provision of accurate plans and sections upon which geological facts and projections might be plotted.Unfortunately, the basic data were very inadequate. For the British Section, sill survey plans were available, but no regular stope plans. Filling surveys had been preserved for many stopes, but on innumerable pieces of tracing linen, without heights of any kind, and not altogether reliable (as indicated by the finding of very inconsistent duplicates). For the bulk of the old stopes no plans exist at all. The expenditure of much time and patience has resulted in the co-ordination of most of the existing stope data, but the British Section must for the rest of its life continue to have surprises in store, as has been the case for many years past. Manufacture and preservation of stope records has, of course, been on a sound footing during recent years. No reliable cross-sections of the British Section were available.The Marsh, Junction, and Junction North Sections have for the most part very poor data. In the North Section, level plans were fairly reliable, and cross sections of the lode made for ore reserve purposes have been preserved for quite a few years. No floor plans of stopes were kept, however, until a couple of years ago.Diamond Drill records vary in quality. Practically none exist for the Junction and Junction North Sections. Logs have been kept for the British Section drill holes, but are...

Jan 1, 1940

The importance of orebody definition and optimisation in project development cannot be overstated. Inappropriate orebody definition is the single most important reason for project under performance and/or failure. Without the firm foundation of good orebody definition, the structure of a project cannot be assembled reliably. Many factors need to be considered in the process of orebody definition. These factors are well summed up in paragraph 123 of The Institute's Code and Guidelines for Assessment and Valuation of Mineral Assets and Mineral Securities (Valmin Code). The factors range from the initial geological data through assaying, geotechnical and hydrogeological factors to mining and metallurgical considerations. There are other factors which also need to be considered including marketing and environmental factors. This paper briefly reviews some of these factors and their impact on project development. Three examples are presented where one or more of these factors have had significant impact on the development of the Project.

Jan 1, 1997

By Graham M

Longwall mining has been the dominant global coal mining method for decades. However, not until 1994 did longwall mining surpass continuous miner room and pillar extraction tonnage in the United States. This significant event, occurring in the most cost driven market in the world, confirms the efficiency and effectiveness of longwall mining.

Jan 1, 1998

By A Sellgren, M R. Carstens, R Visintainer

There is a wide variety of industrial pastes or non-settling slurries pumped in mining, dredging and reclamation projects as products, refuse and tails. The types and/or names of some of the common ones are alumina red mud, phosphate clays, tar sands mature fine tails, tar sands (CT) consolidated clays and fly ash. The pipeline performance or friction of these varies dramatically with the type, its concentration and the particulars of the actual slurry making it difficult to select pumping equipment and to design associated pipelines. The GIW Hydraulic Laboratory in Grovetown Georgia has tested a number of these slurries over the last 30 years for various mining customers. Where available in the public domain and/or where permission has been obtained, the results of those tests are presented in this paper in a form usable for pipeline and pump system designers and users.

Jan 1, 2005

For decades strip mining with discon tinuously operating 'draglines and shovels has been the most economical operation method in the shallow hard coal opencast mines of Aust- ralia, North-America and some other countries. Continuously operating equipment such as bucket chain excavators and bucket wheel excavators in combination with conveyor belt systems, conveyor bridges and stackers had been deve- loped in Germany; during the last 25 years this type of equipment has been further developed in order to allow a high degree of rationaliza= tion as to opencast mines in unconsolidated overburden in Germany, in many European couh- tries, in India and in Victoria. The differing compactness of the layers to be mined, the increasing mining depth, the adverse over- burden to coal ratio and geotechnical con- ditions account for the combined use of con- tinuously and discontinuously operating equip- ment and systems. This paper is to demonstrate some projects showing the combination of continuously and discontinuously operating equipment which aims at optimizing opencast mine operations. It will be reported on the following combinations: - combined use of bucket wheel excavator/

Jan 1, 1981

During the past seven years silver recovery has been increased from 9 per cent to over 61 per cent. The changes in plant practiee which have led to this increase are described. Gold room clean-up procedure has been varied, so that half the additional silver is obtained as pure silver chloride, which.is converted to silver bullion for marketing.

Jan 1, 1964

A real Dorothy Dix title has been selec- ted for this paper. It has the advantage, however, of being capable of being interpreted in many different ways and hence I can select my own approach. You probably are thinking that this topic would be more appropriately handled by an Accountant. I wish to make it clear at the outset that I am not skilled in the sometimes mysterious ways of Accountants - likewise that profession frequently has difficulty in pinning down economists. We have our own strange ideas about profits, marginal efficiencies, cost/benefit analysis etc. What follows is in the main a mixture of two disciplines, probably in a form that few of the purists from either side would accept. Nor do I expect the reader to accept my own prejudices. The paper is designed to stimulate thought and discussion'on the subject. Emotive words such as "profit" and "loss" make for wide differences of opinion. At the time of writing there is a surprising degree of acceptance of the viewpoint that profits in Australia are too low and one is tempted to make this point of near agreement a starting Point.

Jan 1, 1975

By Champigny N, Grimley P. H

To a bank that granted his request for a loan, the late American humorist Robert Benchley responded, `I don't trust a bank that would lend money to such a poor risk'. This quotation is unlikely to be the norm among mining companies that secure project financing. However, a poor appreciation of one of the key risks of a mining project, the reserves, often results in disastrous financial consequences. This conclusion is the subject of the discussion and analyses presented in this paper.

Jan 1, 1994

Although the 'exi'stence of bauxite in Australia has been known for many years it is only recently that exploitation has commenced.. of the two most' important` deposits, strangely at almost diagonally opposite tips of the continent. Recognition of the importance. of the bauxite in the South/West corner came about initially through the efforts of a well-known Australian mining company which,` with some outside financial help, tackled the early exploration with commendable foresight and courage.

Jan 1, 1964

A recently discovered high temperature (22G-2800°C) reaction between glycerol and the oxides and hydrous oxides of iron produces a green, well-crystalline complex glycerato-iron, whereas hydrous nickel oxides an) reduced by the glycerol to metallic nickel. When nickel isomorphously substitutes for iron within the goethite lattice this high temperature glyceration allows a separation of the two metals whereby the nickel can be extracted by solution techniques.

Jan 1, 1971

Portman Mining Pty Ltd very successfully operated the Ferro GullyNorth Mine in the Hamersley Province of Western Australia to satisfy a contract for the delivery of six million tonnes of iron ore in less than two years to the Mount Newman Mining Co Pty Ltd. The high-grade ore extracted from Ferro Gully North Mine was unusual in that, not only was it within the Joffre Member of the Brockman Formation, but it was rich in red ochreous hematite and martite and very low in phosphorus.

Jan 1, 2001

Hilton Mine is located 20 km north of the city of Mount Isa and Isa Mine in far north west Queensland. The sealed road used by the 500 employees to commute from the city is part of the Barkly Highway linking Mt Isa to the Northern Territory.Although discovered in 1947, major underground development did not start until late-1982 and first cut-and-fill production in mid-1987. The J53 exploration shaft was sunk in 1970-73 and the main P49 shaft in 1973-75. Since January 1990, most of Hilton ore production has been treated in the Hilton Concentrator, and concentrates trucked in slurry tankers to Isa for smelting or shipping.

Jan 1, 1993