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By T Howard, J E. Everett

BHP Billiton Iron Ore has replaced the conventional product quality control batch system at Yandi with the Continuous Stockpile Management System (CSMS) centred on a fully integrated æcontinuousÆ stockpile flow from mine planning through to port reclaiming. With increasing tonnage rates, tight operational coupling associated with the original batch system caused production interference which achieved final product quality but in an increasingly inefficient manner. This innovative approach places a continuous emphasis on product grade control and takes full advantage of the most appropriate blending opportunities of the mine to port planning and production system in order to reduce the natural variability of the ore to an acceptable level. To implement continuous control, product variability throughout the process is classified as long-term and short-term. Long-term variability is best controlled through the monthly mine planning process which determines monthly grade targets while taking into account optimum mine development. In the past, attempts to control long-term variability were made at the port through selective stockpiling and reclaiming which reduced operational efficiency. Short-term variability is best controlled around the monthly mine grade target by daily mine production scheduling, train sequencing, stacking into port stockpiles of appropriate size and systematical stockpile reclaiming. The implementation of the new system has maintained customer accepted shipping grades and has provided significant improvements in resource utilisation, operational efficiencies and costs.

Jan 1, 2002

Air tabling of zircon-rich non-conductor products containing quartz enables most of the fine quartz present to be rejected without a markedloss of zircon. The coarser quartz in the air table feed can be separated from the zircon by screening one or more air table products, the oversize products containing most of the quartz and little of the zircon. Air tabling, with or without screening, is more efficient than wet tabling alone for the removal of fine quartz, but not for the removal of coarse quartz. Practically all of the quartz can be separated from the zircon by using wet tabling in conjunction with hydraulic classification, or by using air tabling in conjunction with dry launder treatment, in which a degree of sizing takes place that is advantageous for subsequent air tabling.INTRODUCTIONBack-dune and inland beach sand deposits usually contain fine wind-blown quartz, and neither spiral nor wet table concentration, alone or in conjunction, makes a clean separation of heavy minerals from quartz. Many rutile plants recover rutile and zircon from a low-quartz, wet-table concentrates by means of magnetic and electrostatic separation; some rutile and zircon are lost in the table tailings. Other rutile plants, and two of the ilmenite plants in Western Australia, recover rutile or ilmenite respectively, from a spiral concentrate containing several per cent of quartz, and then subject the non-conductor product to an additionalgravity concentration process to separate the zircon from the quartz. Some zircon is lost in the additional gravity process, but all of the rutile or ilmenite in the spiral concentrate is, or should be, recovered as high-grade concentrate. The higher recovery of rutile or ilmenite by this treatment method is offset by the expense of drying part of the feed twice, as a wet process is usually used to separate the quartz...

Jan 1, 1962

During the last 125 years, the steel industry has witnessed revolutionary changes in the process of steelmaking. The Bessemer process was the predominant steel production technology during the last two decades of the 19th century. The open hearth process accounted for the lion's share of world steel production for six decades from 1910 to 1970. With the appearance of the LD process on the industrial stage in 1952, the importance of open hearth process declined and currently the basic oxygen processes are contributing more than 60 per cent of the world steel production. The LD process also led to the development of several other oxygen blown processes such as LDAC, OLP, OBM, QBOP, EOF, Clc.

Jan 1, 1999

This paper describes the excavation of No. 1 Power Station Lift Shaft at the Kiewa Hydro-Electric Project. The advantages and limitations of the borehole method are outlined, and general principles of plant design are discussed.INTRODUCTIONFor many years, attempts have been made to reduce mine development costs by various methods. Some of the, techniques of tunnelling have been adopted in horizontal headings, and in main vertical shafts, mechanical plant has displaced hand labour with notable success. However, in the field of small rises and winzes, improvements have largely been effected by attention to details of procedure. The most promising avenues for' substantial reductions in cost relate to:(a) Long-hole drilling(b) The borehole method(c) Calyx drilling.Whilst each of these methods has its peculiar advantages, the borehole rising method is probably most useful, and capable of wide application.In brief, the borehole method of rising requires a, drill hole parallel to the axis of the rise. A hoisting rope is passed through the borehole, and is attached to a platform on which the rising crew are raised with their equipment to the drilling position in the rise.When properly planned, the method is particularly safe, and has generally received the approval of mine inspectors and safety authorities. Rising work is generally hazardous, even when special timbering methods are used. In...

Jan 1, 1959

By A Singh, C Da Corte

Banded Iron Formations or more commonly known as BIF are sedimentary rock formations with alternating silica-rich layers and iron-rich layers that are typically composed of iron oxides (hematite and magnetite), iron-rich carbonates, and/or iron-rich silicates. Considering the depletion of highgrade iron ore reserves in South Africa, there is a need to maximise resource utilisation through the exploitation of sterile resources in particular BIF material which makes up greater than 65 per cent of current reserves. BIF, like most resources, is non-renewable and the deposition of BIF is thought to have come about by the reaction of Fe2+ ions in the ocean water with dissolved oxygen billions of years ago. BIF ore derived from the Limpopo region in South Africa (SA) located in the Penge Iron Formation is according to Cairncross, Kramers and Villa (2018) equivalent to that contained within the Asbestos Hills Iron Formation of the Transvaal Supergroup in the Northern Cape, SA. Considering that these are one of the largest iron ore deposits in SA, the case study involved mineralogical characterisation followed by beneficiation of BIF from these two regions to ascertain the comparability. Coarse and fines gravity separation comprising of Heavy Liquid Separation/Dense Media Separation on the +1.18 mm size fraction and shaking table on the -1.18 mm size fraction was conducted to ascertain whether an on-grade product or blended feedstock could be produced. The Limpopo mixed and Northern Cape conglomerate BIF samples achieved similar overall responses due to the conglomerate sample containing 15.3 per cent additional -1.18 mm fines. A combined coarse and fines product grading at 60 per cent Fe could be achieved at a yield and recovery of 43.9– 53.0 per cent and 62.2–63.8 per cent respectively. Increasing the grade to 63 per cent Fe reduces the overall recovery by 13.3 per cent. At the higher target grade, the contaminant specifications could be achieved for both samples. The Northern Cape laminated BIF sample is the most promising of the three samples studied. At the two iron target grades overall yields and iron recoveries of 72.9–65.4 per cent and 85.2– 80.2 per cent was achieved. In both instances the silica grade exceeded the product specification, however if the silica content is the driver the target iron grade should increase to 63.32 per cent. This will result in a minimal decrease in recovery of 0.4 per cent. The promising results of this study indicate that coarse beneficiation of BIF material is possible. These ore types could be blended with superior grade products to improve overall yields and recoveries or sold directly at a 63 per cent Fe product grade whilst sacrificing 0.4–13.3 per cent recovery.

Nov 8, 2021

By M A. Tuck

The dominant heat loads in a deep underground mine are the surrounding rock mass, autocompression and machinery. In addition heat can be contributed to by other sources. Many block cave, sublevel cave operations and coalmines utilise conveyors to transport broken rock out of mine, in some cases completely, in others in combination with other forms of transport. This broken rock can be loaded onto the conveyor at virgin rock temperature and can represent a major heat input to the ventilation airflow as it is transported out of the mine. The purpose of this paper is to review established knowledge regarding heat flow, from conveyed rock to determine the main factors influencing the heat flow and to develop a methodology for predicting heat flow from caved rock. The paper concludes with suggestions for further research in the area of conveyed rock heat transfer.CITATION:Tuck, T A, 2017. Accurately estimating heat load from conveyed rock, in Proceedings Australian Mine Vent Conference 2017, pp 225–230 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

Slime Flotation Using Ethoxylated Surfactants in Solutions of the Electrolytes

Sep 13, 2010

By A Llewellyn, M Varvari

The ventilation circuit at the FrogÆs Leg Mine was originally designed to permit mining to progress down to 440 m below surface at a maximum production rate of 500 kt/a, as per the feasibility study. The FrogÆs Leg resource has now been defined down to 640 m below surface at a maximum production rate of 750 kt/a. In order to allow for this increase in production depth and tonnage, it was necessary to upgrade the ventilation circuit.This paper outlines the upgrades to the ventilation circuit that were undertaken and the underlying rationale behind them.CITATION:Llewellyn, A and Varvari, M, 2013. Ventilation upgrade at the FrogÆs Leg Mine - Case study, in Proceedings The Australian Mine Ventilation Conference , pp 95-102 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 1, 2013

THE object of the air-tight stopping is either to prevent a current of fresh air from getting into the fire area, or to prevent an escape of fumes and gases from the fire area into the workings of the mine. In the former case all is "plain sailing," but in the latter case there are certain difficulties to be overcome.In the Broken Hill Proprietary mine there were two styles of stopping used during the last fire-brick and bag and the following were the chief points that determined the use of one in preference to the other:-If the required stopping were to be more or less permanent, bricks were used, also if the area to be blocked were large-bricks being so much lighter and easier to handle than bags filled with -skimps. If, however, the air contained much gas, a bag stopping was put up. Great difficulty was experienced in getting essentially surface men, such as bricklayers, to work where there was the; slightest trace of gas; miners, however, would willingly do the work, and a bag stopping could be built without skilled labour.In old drives and gangways, where there was the liability of settlement, the bag stoppings were preferable to brick. The slightest movement around the sides or foundations of the latter would cause cracks, thus rendering the brick stopping useless;whereas, in the former, there was a certain amount of elasticity.

Jan 1, 1909

By S Whitton, W Wimmler, L Wimmler

“Given the increasing scrutiny of the mining industry and its relatively poor record with regards to mine tailings management, increased requirements to minimise water usage (often accompanied by very high costs of water) and the need to demonstrate achievable long-term closure strategies, it is likely that the option of a filtered tailings system will need to be considered in many operations in future.” (Australian Centre for Geomechanics, 2018). Given such a statement as a conference introduction, it is only appropriate that a range of potential technologies are investigated and compared, to create awareness for even underrated but appropriate technologies. The advantages and disadvantages of all technologies need to be considered and analysed. Suppliers are swift to promote their technologies advantages; however aspects of sustainability are not always fully understood. Perhaps a combination of two filtration technologies is appropriate. This paper delves into the technical details, good or bad, of four mechanical dewatering technologies in tailings dewatering and provides insight on an undervalued and, in the author’s opinion, young technology – the screw press.

Jul 1, 2021

By P Cherepanskiy, G Elphick, R Hus, C Perring

When an iron orebody nears its end of life, the extracted material can become increasingly problematic to handle. Higher moisture content occurs as larger portions of originally-below-water-table material is mined, which in some deposits is accompanied by further changes in physical and/or chemical properties present along the edges of the orebody. Plant delays related to problematic material have affected all of BHP’s mining hubs to various degrees. Following the recent successful work in Yandi, where the development of an index to quantify the handleability of channel iron ore deposits resulted in an increase in extracted volumes and an extension to the expected life-of-mine, the value of implementing similar indices for bedrock iron ore deposits has been recognised. A materials handling index has been developed by combining observed empirical relationships between material properties and processing plant performance. Indices for each deposit were further refined and optimised by implementing a back-testing strategy which facilitated an understanding of what weighting or scaling each of the contributing components should carry to yield the highest success rate of predicting actual delays at a given plant. Currently materials handling indices are deployed to all mine sites and are made available in block models as well as calculated for individual blasthole and production samples. Values in block models are obtained by predicting the required properties using machine learning models, whereas hyperspectral data is used to ‘measure’ some of those properties on a sample level. This paper discusses the work that has been undertaken to obtain materials handling indices, the testing that has been done to optimise them, and what processes have been developed to ensure the best metrics are being used in the different planning and scheduling horizons to optimise extraction.

Jun 22, 2022

With commodities suffering dramatically low real prices, mining business margins are under intense scrutiny. Unfortunately, management systems developed early this century for manufacturing are driving counterproductive behaviours that choke productivity. The paper and presentation will explain this and present a proven methodology for increasing productivity. This will be supported by operational examples from Australian and American mining management to demonstrate the importance of modern business performance measurement and analysis systems. It will explain the importance of management systems in driving organisational change to sustain superior productivity and margins. The paper will explain why many executives and managers confuse production (a measure of volume) with productivity (which measures efficiency and effectiveness). It will explain how this and other counterproductive managerial and operator behaviours and attitudes are driven by traditional business management systems exacerbated by managerial and consulting fads. The paper will begin with the simple principle that to improve results one needs to first improve the process producing the result û and will show how this is often violated. Improving productivity then boils down to:accurately identifying opportunities using sound, modern measurement, analysis and reporting systems; methodically improving operating and commercial processes, and changing peopleÆs behaviours and attitudes to sustain changes in practices. The paper will include fundamentals of applying sound measurement and analysis to:processes directly, eg cycle time charts and their impact in cyclical (non-continuous) operations commonly used in rock breakage; drivers of productivity; and process results themselves since correct analysis identifies opportunities accurately. The paper will cover the importance of practical leadership and the need to follow a simple, solid plan for changing systems that drive behaviour. Overall, it will highlight use of modern performance Measurement, Analysis and Reporting systems to drive behaviours and improve margins - without capital investment û and make executive and managerial work easier and more effective.

Jan 1, 1999

Mr. BRADFORD said :-On assuming this chair, which has been occupied by so many gentlemen of conspicuous ability; my first words must be an expression of the gratitude I feel for the honour you have done me in electing me to be your President for this year.When considering the subject matter of this address to you to-night, quite frankly may it be stated that for a long time I was on the horns of a very great dilemma, for while I could discourse on the modern political trend in relation to our industries at great length, it appeared to me that this was not the place for such a discussion. Next I turned to a consideration of whether a discourse on the theory and practice of iron and steel would be of interest.I, however, banished this idea also from my mind, because it appeared to me that you have already had a surfeit of this on your visits of inspection to our local industries and I did not want in any way to be held responsible for the iron entering into your souls! I therefore propose, with your kind consideration, to address you on other subjects of common and vital interest to all.My first words and thoughts turn on the absolute necessity of eliminating waste in our methods. If we are to succeed in our...

Jan 1, 1926

Six years ago it was my responsibility to give the presidential address, and now that privilege has come my way again. On that occasion we were gathered atWhyalla and I took the opportunity of putting before members some observations on the problems we then faced in Australia, and some gains we had been able to chalk up during those early postwar years. You may recall that we were then just beginning to emerge from the difficulties of postwar reconstructions - of fuel and power shortages, and a grossly inadequate manpower for the tasks facing us. The expansion of manufacturing industry in Australia greatly stimulated by wartime activities, and by the postwar developments of many institutions - ran ahead of the supporting services and of the supply of labour to do thejobs. For many industries this unfortunate state of affairs had meant operating at rates well below their installed capacities and therefore levels of output insufficient for Australia's rapidly growing needs. When I last spoke to you these problems were still with us, though their intensity was beginning to lessen as a result of vigorous efforts by industry and governments to reduce them. But I must confess that my thoughts on that occasion were full of those problems and of the effect they were having on the iron and steel industry of this country-of the coal shortage, the labour shortage, and the many other difficulties we were then faced with - and all at a time when the stepping up of our postwar expansion programme was of vital concern to all of us.What a different picture it is six years later! How greatly has the scene changed for the better. In 1951 Australia's postwar immigration programme was only in...

Jan 1, 1957

Five types of mineral resource were known in the sedimentary cover of the oceans and seas floors prior to the 1980s: 1. hydrocarbon fields including some very large zones of oil and gas accumulation; 2. æRed SeaÆ type thermal oozes with increased concentrations of noble metals; 3. ferromanganese nodules; 4. concentrations of metallic sulphides (æBlack SmokersÆ); and 5. cobalt-bearing ferromanganese crusts on the summits and slopes of seamounts.   Since then, the so called æWhite SmokersÆ, containing sulphides of copper and zinc, have been discovered. The ore horizons (manganese, copper, nickel and other metals) of the sedimentary cover of deep-sea basins comprise a sixth type of mineral resource in the oceans. These horizons have not only a theoretical, but also a principal economic significance.

Jan 1, 1995

Inhibition of Bubble Coalescence by Salts and Sugars

Sep 13, 2010

This paper is a collection of thoughts and frameworks. It addresses a simple question: æIf we are to believe the large number of people and institutions indicating that humans are destroying the Earth and that the end is nigh, why do we bother trying to be sustainable?Æ The paper lays out evidence for the existence of multiple hazards to global society. The existence of a hazard alone is insufficient to make an assessment of risk. Risk estimates are required to support decision-making. An approach to assessing risk is provided and some limited data are presented. A new ædefinitionÆ or statement of what sustainability (in a broad sense) might have become is then given. A decision framework for guiding decision- making about the risks is developed. This framework includes a definition of leadership with inherent implications for what determines whether a leadership position by title is actually leading. The paper concludes by offering a view of minerals industry sustainability and considerations around maturity in the current economic situation. It is hoped that by placing this collection of frameworks around sustainability, a supporting structure emerges that will facilitate action. It is proposed that action taken in this way will be more effective than reaction to regulation or even social license to operate imperatives because it is driven by a more holistic view of the challenges and the potential roles of individuals û all of whom are potential leaders at some scale of action.

Jan 1, 2009

A number of mineral deposits occur in close proximity to the Pacific plate fronts. Among these deposits are gold-silver and the base metal sulphide deposits of copper, zinc and lead. Gold deposits that commonly occur in these areas are of hydrothermal origin. Of these the epithermal deposits have attracted the attention of the exploration geologists as well as the metallurgists. One vital aspect of the activity of the geologists is the development of models for epithermal gold mineralisation in the Pacific Rim. These models can also be used by metallurgists for predicting gold extraction processes. This paper reviews the mineralogy, fineness and the host minerals of gold and examines the data in the light of gold mineralisation in the southwest Pacific Rim. The gold mineralisation models proposed for the Pacific Rim have been used to predict gold extraction processes suitable for the various mineralisation types. Discussed also are the mineralisation and treatment processes of some selected epithermal gold deposits and gold-rich porphyry copper deposits in Indonesia, Papua New Guinea, Solomon Islands, Fiji and New Zealand.

Jan 1, 1999

The effect of conditioning energy input on the metallurgical results of an emulsion flotation process has beenattributed by previous authors to a detergency process.This paper shows that such a process does not explain the data and that an attrition mechanism is more appropriate.

Jan 1, 1970

By A Rantala, K Aberkrom, O Haavisto, P Blanz

More complex ore bodies with lowering grades increase the challenges of maintaining high throughput, energy efficiency and required particle size for optimal downstream processing in grinding circuits. Continuous and often rapidly changing characteristics of the mill feed requires constant focus to operate the circuit at optimal level. Modern process instruments, on-line analyzers, monitoring and process control systems provide attractive and managed options to increase the circuits’ capability to respond to the challenge, often in phases and in rather short time period. Furthermore, well instrumented and performing base level automation in the grinding circuit enables advanced process control (APC) strategies that utilize measurements from the whole circuit to stabilize and optimize production. In this paper alternatives for incorporating process measurements and controls to typical grinding circuits are proposed. The expected benefits to throughput, availability, energy efficiency and particle size stability are described in recent case examples.CITATION:Rantala, A, Blanz, P, Aberkrom, K and Haavisto, O, 2015. Increasing grinding circuit robustness with advanced process control, in Proceedings MetPlant 2015, pp 129–141 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015