Search Documents

By Phillip J. Mackey, Gerardo R. F. Alvear F.

It is now 38 years since the publication of the first edition of "Extractive Metallurgy of Copper" by Professor W.G. Davenport and the late Professor A.K. Biswas. The text book would be issued in a total of five editions, soon became the standard for students and those in industry. Interestingly it was published at the onset of great change in the industry. This was a time when sulphur dioxide controls in the USA were introduced, and almost simultaneously, world oil shocks caused significant increases in the cost of fuel - all leading to efforts to adopt new technology and move away from the reverberatory furnace, which had no potential for sulfur capture and required large amounts of fuel. At the time of publication of the book, new processes such as the Noranda Process and the Mitsubishi Process were in their infancy, while flash smelting (which was first commercialized in 1949 at Harjavalta, Finland) had made significant in-roads in boosting copper output, with some 22 new flash smelters licensed by 1976. Computer technology and associated process control techniques were rudimentary compared to systems today, available physico-chemical data remained largely in tabulated format and needed to be manually entered into the main frame computers of the era, while modeling techniques common today had not yet been developed. The copper industry has therefore seen immense changes since the time of this textbook: world tonnage of smelted copper has risen from 7.34 million tonnes/year in 1976 to 16.7 million tonnes/year in 2012, over a two times increase. Technologies such as the El Teniente Process, or Top Submerged Lance technologies, typified by the ISASMELTTM, not commercialized at the time, now treat large tonnages of copper concentrate in a single furnace. Advanced heat and mass balance software and thermochemical modeling are now used extensively to examine chemical and physical characteristics for process design and to support process optimization. These changes in the industry have been chronicled in subsequent editions of the book. This paper looks at the issues and problems seen in 1976 and over the intervening years, and compares this with the challenges facing the industry with the available tools and technologies today. Some ideas looking into the future are also discussed in the paper.

Jan 1, 2014

By Jones S. C

A specific arc can be cut in hard rock formations using a specially designed multistep piloI bit, variable sized drift joint and long heavy control rod as a stabilizer rather than the Vaughan Thompson "Lifting" arc cuttingequipment. The rate of deflection can be controlled after an initial determination of behaviour in any particular rock type.

Jan 1, 1966

By Arthur G. Hunt

Smelting using the direct-to-blister process commenced at Olympic Dam on 31 July 1988. The unique nature of the Olympic Dam ore body led to the selection of the direct to blister smelting process. Significant improvement in the design of the furnace and the understanding of the fundamentals of the process and its operation has occurred in the 10 years of operation. The paper will discuss the operation of the #1 Smelter and the design, preparation for start up and early operating experience of the #2 Smelter.

Jan 1, 1999

The brown coal deposits of the Latrobe Valley are ideal for open cut mining and this method has been used since the start of coal winning in 1894. Operations at the main Yall9urn open cut commenced in 1922, but after a few years the main excavators were replaced by German continuous excavators and subsequent developments of Yallourn and the newer Morwell open cut have been based on this type of plant. The reasons for preferring continuous to intermittent excavators in the Latrobe Valley are indicated in this paper.Under the pressure of post-war conditions, and from their long experience and ability, German engineers have recently made substantial improvements in their continuous excavators and these developments have been enhanced by some American innovations. These changes have extended the economic limits of open cut mining and also serve to emphasize the close inter-relation between the nature of coal and overburden deposits, excavator design and methods of operation.As an aid to descriRing recent excavator developments, this interdependence is demonstrated by means of diagrams which show typical methods of operations, together with examples of actual machines using these methods. The types of excavator dealt with are mainly those in use at, or destined for Yallourn or Morwell open cuts, together with additional types used in U.S.A. and Western Europe. For completeness, and also because they will continue in service at Yallourn and Morwell for some years, rail-mounted dredgers have been included in this paper even though in Europe they are now regarded as obsolescent.Explanations are given of how the intrinsic qualities of Latrobe Valley brown coal and overburden have sometimes prevented overseas plants from operating with the full efficiencies and/or in the methods visualized by the manufacturer, and references are made to the modifications and investigations being undertaken to overcome these problems.A compresensive bibliography is given. Dates shown on illustrations are not commissioning dates of the plant concerned, but the year when photographed.

Jan 1, 1960

By R. O. Burt, D. J. Ottley

"SYNOPSISRecent developments in the use of the Bartles-Mozley table and the Bartles CTS screen are described for the gravity preconcentration of fine heavy mineral and metal particles present in low grade pulps. The B-M table is a relatively new device used for the recovery of particles of up to 100 micron size down to 5 microns or in the case of gold and platinum, down to 1 micron. The CTS screen is a wet screening device used for feed preparation ahead of the Bartles-Mozley table and will size effectively down to about 300 mesh. Results and operating data for a number of different materials are given including outline flowsheets; the effects of the major variables on the performance of the table are briefly discussed. The potential of the B-M table to treat a variety of different ores, coal, tailings, and waste products are considered. The utilization of the B-M table in association with other unit processes to improve overall results as well as to improve the economics of design and performance of plants are also mentioned.INTRODUCTIONA number of new gravity concentration devices have been developed in recent years for the recovery of fine heavy mineral and metal particles but for reasons which include low capacity, high capital or operating costs, competition from other and better processes, the absence of simplicity or reliability in operation etc., only a few which include the Bartles-Mozley table, have been proved to be of commercial application.The name of the machine is derived from the inventors name, Richard Mozley, who developed the B-M table at the University of Bristol in England. The table was subsequently taken up and patented, world-wide, by the National Research Development Corporation a British government agency. An exclusive license to manufacture the table was granted by NRDC to Bartles (Carn Brea) Ltd. in Cornwall, England."

Jan 1, 1973

By John A. Herbst

Flotation control systems in use around the world today owe their effectiveness to the coordinated use of appropriate sensors, control hardware, and decision-making strategies. This paper traces the development of these three main elements of the "control triangle" over time. Based on an analysis of recent developments, it is concluded that improvements occurring in instrumentation have basically been evolutionary, while advances in hardware and strategies have, in contrast, been revolutionary. An attempt is made to extrapolate developments in each of the "control triangle" elements into the future in order to make a projection concerning flotation control systems for the next millenium.

Jan 1, 1999

By T. Gerritsen, A. Matyas, F. Stober, I. Candy

This paper describes developments in ferro-nickel furnace technology, specifically improvements to cooling methods, furnace controls, and high voltage furnace operating regime. The evolution of these technologies is briefly presented, as context for describing the current state of the art that has enabled ferro-nickel furnace operation at over 75 MW and specific energy consumption of less than 400 kWh/t dry ore. Examples from existing operations are used to illustrate present best practices, and potential future trends are discussed. The paper begins with an overview of the fundamental aspects of pyrometallurgical treatment of lateritic ores that drive ferro-nickel furnace design. Furnace wall cooling methods are related to the requirements resulting from specific furnace process conditions, including slag and metal compositions, as well as arc and bath power. The benefits of high productivity and low specific energy consumption resulting from high voltage (shielded-arc) operating practice are discussed, along with the furnace controls and electrical power train that enable such operation even with captive power generation.

Jan 1, 2004

By Whitworth N, Anderson P

New plant has been commissioned to treat off-gases from the Fluo-solids Reactor in the Copper Smelter. The new section of plant was built onto an operating system and commissioned with minimum disruption to production. Under construction is a 270 m tall stack for Lead Smelter gases. Additional items for the Lead Smelter will include a new gas cooler, a central baghouse to replace Sinter Plant wet gas scrubbers, a new exhaust fan on the main baghouse, and ducting of drossing gases to the main baghouse. Emphasis is given to discussing improvements the new plant has made to working conditions, the general environment and increased production capability. Total expenditure in the two smelters is in the order of $25 million.

Jan 1, 1978

By Hughson B

At present sane man-made Improvements and natural features are constraints on unlimited underground mining. 7 hey will continue to remain, as constraints on the future high production mining systems as wall. Unless these constraints are overacTe by research, where possible, future high production systems may became unacceptable. 7 he areas of future research include improved subsidence prediction techniques applicable to future mining systems, subsurface subsidence behaviour, mining systems capable of producing no surface subsidence and subsidence damage assessment.

Jan 1, 1988

By Christoph Broeckmann, Andrew Gardula

"The adoption of high-pressure grinding throughout the cement industry has yielded enormous savings in energy and wear material costs. There are also a number of installations, which are applied in iron ore and kimberlite processing operations. High pressure grinding offers the same potential for energy and media savings, as well as opportunities for improved, downstream metallurgical performance, in hard rock mineral processing. This paper focuses on developments in machine design and wear surface engineering for high-pressure grinding of the hard rock ores in the mineral processing industry.INTRODUCTIONIn the early eighties 3.4 % of the world electric energy was consumed for crushing and grinding operations of minerals and 0.6 % in the ore dressing industry. During that time using a laboratory press Prof. Schönert found that interparticle comminution at high pressure requires remarkably less energy as conventional grinding technologies. In grinding of cement clinker he expected energy savings between 33 and 50 % compared to ball mills [1]. Piston presses are limited in throughput. Thus, the principle of interparticle comminution was adapted by the use of high pressure grinding rolls (HPGR) to a continuous plant process. Figure 1 shows the main components of a roller press: The roller nip of width s is formed between the floating roller (1) and the fixed roller (2). The diameter of the rolls will be denoted with D, the width with B. The total press force F can be adjusted using a hydraulic system with two or four pistons (3). In order to compare machines with different roll geometries the specific pressing force p is introduced:"

Jan 1, 2005

By Stober, Frank Allan

The paper describes the development of components in an lntegrated Furnace Control system for shielded-arc smelting focusing on operation and crucible integrity enhancement. The paper reviews the mechanisms of power, feed and energy input and losses into the shielded-arc smelting process and describes the furnace control system module development and integration to tailor the process. The ultimate success of a furnace control system application is transfer of knowledge, training, and operational support during furnace start-up and ramp-up phases and a model for how this has been achieved is discussed. The control modules of a shielded-arc laterite smelting furnace are described in detail including measured results and screen captures from application in a laterite smelting furnace. This paper focuses on developments in Integrated Furnace Controls tailored to shielded-arc laterite smelting but development of common furnace control modules for improved crucible and tapping operation integrity applied to other furnace processes, including immersed-arc smelting, is also covered. Keywords: IFC, Power, Feed, Supervisory, Control

Jan 1, 2004

The results of laboratory grindability tests on coal are of primary importance to the designers and operators of coal grinding mills, and coal handling plants in general. However, the potential industrial application of these test results have not been fully realised due to a lack of laboratory-test/field data correlations. This paper focuses on the grindability characteristics of Queensland coals, and provides a new look at an old problem in terms of (i) a more rigorous characterisation of the grindability properties of coal and its associated mineral impurities, and (ii) the correlation of laboratory grindability test results with the size characteristics of run-of-plant thermal coals, and their pulverising characteristics in full-scale mills. A new grindability test is also proposed based on the Yancey, Geer and Price laboratory abrasion-test mill.

Jan 1, 1991

By Johnson N. W, Munro P. D, Pease J. D

The Lead/Zinc Concentrator of Mount Isa Mines Limited processes complex fine grained ore from the Isa and Hilton silver-lead-zinc orebodies, producing lead concentrate, zinc concentrate and (until 1996) a low-grade middlings (LGM or bulk) conc

Jan 1, 1997

By Greenhalgh L. P H

The opportunities offered by an increasingly volatile world invite the international consultant or engineering services contractor to broaden attitudes, diversify interests, expand capabilities, retain and develop specialist skills and base judgements upon sound principles and solid experience. The wide-ranging scope of this review reflects such a change but the topics of discussion are not intended to be exhaustive or to detract from many other current developments.The subject of environmental protection, effluent control and pollution prevention is a primary consideration in the application of many mineral processing technologies but is not covered here. There is an array of developments relating to noxious gas emissions and toxic wastes and the paramount importance of this matter justifies comprehensive conferences dedicated solely to the application of suitable measures. This review concentrates therefore on the main stream processing techniques for the primary recovery of values.

Jan 1, 1993

By Palmer C. G, Rowe P. G

Ore handling improvements at Mount Isa Mines Limited were necessary to keep abreast of technological advances in all phases of sublevel stoping practice.In the early 1930s an efficient ore handling system was in operation.However in 1936 excessive water encountered in deepening the hoisting shaft necessitated the sinking of a second hoisting shaft. Financial difficulties prevented abandoning the original shaft and surface ore handling and crushing facilities, so ore was transferred underground and underground crushing deferred. It was not until 1951 Jhat multilevel crushing permitted increased efficiency in the handling of ore from stopes. Ore was then hoisted in one shaft and transferred on the surface by conveyor belt to a new crushing plant.In 1956 a planned production increase from 5,000 to 11,000 tons per mining day made possible further improvements in ore handling. Larger equipment was installed and existing equipment modified to capacitate the handling of larger sized ore at increased daily tonnages.INTRODUCTIONThe intensive exploratory programme commenced in 1954 disclosed large reserves of both lead and copper ores and in 1956 an expansion programme was initiated to increase production from 5,000 to 11,000 tons per mining day. The increased tonnage would result in decreased costs per ton and further cost reductions would result from increased mechanisation underground. The combined effect would permit larger tonnages of lower grade ores to be included in ore reserves. To achieve both cost reduction and the scheduled production increase, improvement in ore handling was of vital importance.For efficient and low cost sublevel stoping it is necessary to maintain an economic balance between...

Jan 1, 1961

By A. E. M. Warner

At the Copper Cliff Smelter, Inco Limited has extensive experience in converting primary smelting mattes over a broad range of nickel/copper ratios and compositions. In the past 35 years, technology developments at Inco have reduced the number of Peirce-Smith converters in Nickel/ Bulk (nickel-copper matte) service from 13 to the current 5. This paper will discuss: ? The performance and life of ?stretch? 13.7m shells versus conventional 10.7m converters. ? Process control and information system development from the early 1980?s to view converter aisle status on a continuous basis to the recent central control of the stretch shells. ? Nitrogen cooling of finishing matte from plant testing to implementation in the early 1990?s to replace the dedicated cooling converters. ? The impact on converting of changing the smelter flowsheet in the early 1990?s. ? A current program to develop a converting strategy for the future to address environmental issues and profitability.

Jan 1, 2005

Diesel Particulate Matter (DPM) issues are very high profile currently in both Australian coal and metal mines and Australian states are generally moving to acknowledge and to broadly follow US 2008 final metal/non metal mine regulation limits of 0.2 mg/m3 submicron particulate matter, 0.16 mg/m3 total carbon particulate and 0.1 mg/m3 elemental carbon particulate. The real time DPM monitor is being developed on the base of the successful Personal Dust Monitor (PDM) unit. The objectives of recently completed Australian Coal Association Research Program (ACARP) study has been to finalize the design of a DPM unit, to undertake comprehensive and internationally recognized laboratory testing to evaluate the new design and to undertake an underground series of tests to establish the robustness and reliability of the new approach. Under the project Thermo Fisher Scientific has undertaken structural changes to the PDM to convert it to a DPM real time monitoring underground instrument, the D-PDM. The Pennsylvania Pittsburgh Research Laboratories of NIOSH (the group that originally contracted for the PDM development) has undertaken laboratory ?calibration or verification? testing. A phase of Australian mine robustness and engineering testing has been undertaken to ensure the instrument can effectively assist mine management to handle this health issue. Tests have been undertaken at points of expected high atmospheric DPM such as during Longwall face moves, Development RAM car, Eimco and PJB usages. The paper discusses how the monitors have performed within the underground mine environment in evaluating DPM during the various phases of the production cycle. They have closely examined the influence of aspects of the mine ventilation system. Results have been compared to alternative industry pollutant measuring approaches. The outcome of the project gives the industry access to an enhanced tool for understanding the mine atmosphere in the presence of DPM. Real time DPM monitoring will allow the industry to pin-point high exposure zones such as those encountered in coal longwall face moves where various vehicles work or in areas of constrained or difficult ventilation. Identifying of high DPM concentration zones allows efficient modification of work practices to reduce underground miners? exposure. Some outcomes of the ACARP project in this area will be discussed.

Jan 1, 2009

By Eric S. Weiss, Deno M. Pappas, Timothy M. Barton

During the past few years, the Pittsburgh Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) has been evaluating developments in sealant support systems from a ground control perspective. The proper selection and use of a sealant material can significantly enhance ground control which may result in a decrease in worker related injuries due to ground falls. The purpose of this paper is threefold: to briefly review the current state-of-the-art technology in shotcrete and membrane developments, to evaluate the preliminary findings of a long-term underground study of various types of sealant materials, and to examine installation practices that are critical for an effective sealant material. The underground study utilizes NIOSH’s Lake Lynn Laboratory Experimental Mine to evaluate the long-term performance of several types of shotcrete and membrane materials. Sealant performance to date have been evaluated on a regular basis over a two year period. Although the study is still ongoing, critical mining practices were identified that may seriously effect the bond of the sealant materials to the mine roof and rib; most notably, the importance of scaling and thorough cleaning of the rib prior to application. Also, results froman extensive series of Schmidt Hammer tests found that the shotcrete increased in strength by 70% during the humid summer months.

Sublevel open stoping (S.L.O.S.) was introduced at Rosebery in 1972 in the wider ore blocks below 14 level, largely replacing cut and fill methods which had been in use up till that time. During 1973/74 the method produced 10% of primary stoping tonnes, and by 1981/82 it increased to 65%. Because of the increasing reliance placed on sublevel open stoping for primary stoping production, every effort was made in both planning and operating to: - maximise ore recovery and reduce dilution - increase productivity - reduce costs.

Jan 1, 1982

The changes in layout and design over 48 years, from the first crushing and shiploading plant installed at Whyalla in 1915, up to the present plant being built at Koolan Island, Yampi Sound may be summarized as follows.1. Smaller motors and lower power consumption have resulted froma. oil lubrication, where practicable, in place of grease,b. a high pressure "oil-lift" device to reduce starting torque in crushers with white metal bearings, andc. roller bearings in place of white metal.2. Short centre drives with pivot-based motors permit controlled loads on bearings and a reduction in size of crusher houses and motor rooms.3. Dust proofing and pressurising of crusher houses and motor rooms reduces working temperatures and improves cleanliness.4. Variable speed pan feeders give improved plant control, with the use of one man only, and remove the need for large surge bins between crushing stages.5. The use of diesel quarry trucks to dump ore through a "drive over"tip results in faster truck cycles.6. Elevated cylindrical silos with air operated chutes, replace long horizontal storage bins with multiple manually operated side discharge chutes for loading rail cars, and give faster and more accurate truck loading. The silos are charged by belt conveyors with automatic distributors.7. Increased shipping bin capacity (40,000 tons at Whyalla and 6O,OOO tons being built at Koolan Island) caters for the bigger vessels now in use and envisaged for the future. Automatic travelling distributors deliver ore to the bins in layers to ensure, maximum mixing and a more uniform grade for blast furnaces.INTRODUCTIONThe Broken Hill Proprietary Company Ltd has six major crushing plants in Australia at its principal sources of raw material. These are at Iron Knob bench G, Iron Knob scree ore plant, Iron Baron, and Cockatoo Island, all of which are ironstone operations. The other two plants are at Rapid Bay, a limestone quarry, and at Ardrossan, which is the Company's only source of dolomite.

Jan 1, 1963