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By Claude Bazin, Robert Grant, Mike Cooper

An analysis of the Pb recovery as a function of particle size was carried out for the CuPb rougher bank of a complex sulphide mineral processing plant. Results indicate that higher recovery may be achieved by optimizing the flotation feed size distribution. Simulation of the actual grinding circuit has provided guidelines to modify circuit operating conditions in order to improve product size distribution. Plant tests ar

Jan 1, 1991

Improvement of drilling operations through the development of new, unconventional drill bits is a prime research target at Sandia Laboratories, Albuquerque, N.M. Sandia is currently focusing efforts on four new bit designs which its engineers believe may eventually improve penetration and reduce operating costs. The Energy Research and Development Administration (ERDA) has budgeted $500,000 in support of this program to date. Two of the drill bits-one that chips rock with high voltage spark discharges, and another which fires small projectiles into the rock ahead of a regular roller bit-are designed to increase both penetration rates and downhole bit life.

Jan 8, 1975

By David M. Parkes

This paper outlines the achievements to date at the British Columbia mine of Kaiser Resources Ltd. Almost one million raw short tons (855,000 metric tonnes) are now produced per year from a single monitor operation working 15 short shifts per week. Progress has been made in reducing the angle at which coal will flow in flumes by modifying the shape and the plastic linings. Improvements have been made in transporting coal from heading machines, and in the design of the present and future coal: water circuits. The development of hydraulic mining is still young and many improvements are being made.

Jan 1, 1976

By Ernst Raphael

Mechanical drives of belt conveyor drives have experienced a huge amount of improvements concerning technology, manufacture and product structure that reduced investment and maintenance cost significantly. Most of these improvements were of technological nature in the'70s and '80s of this century; whereas, the present decade requires products that meet technical excellence as well as commercial advantages such as quick delivery, low cost and reliable spare parts supply. The best approach to meet these requirements is a highly modular and standardized system of reliable components that cover all demands a conveyor drive might require.

Jan 1, 1998

By J. M. Dean, R. L. Grayson, R. D. Begley, G. L. Winn

Evidence has accumulated indicating that cultural change toward safer workplace behaviors is beginning to occur systematically in the coal industry. Through a range of programmatic mining company successes, enforcement and litigative actions, economic responses to competition and integrated efforts by federal and state agencies, a broader participation of safety and training professionals is being achieved to address prioritized workplace problems at mines. Small steps in workplace-related improvements have been realized already, but the trends in industry safety statistics, coupled with focused programmatic initiatives, indicate that more definitive and systematic steps are occurring to improve safe behavior in the workplace routinely.

Jan 1, 1998

By C Hall, P Hazell, C Wilson

Every mine is situated within a water catchment – a catchment with potentially many other land uses. A mine may take up a relatively small area in that catchment, but its operations have the potential to affect the whole catchment and long after that mine has ceased to operate. Therefore, the residents of any given catchment have the right to feel secure in the knowledge that their catchment, and indeed the wider environment, will not be degraded by mining activities. Much conflict can arise when this confidence does not exist.But, imagine if a community not only felt confident that their catchment would not be degraded by mining activities, but was also confident that their catchment would be left in a better and continuously improving condition – with improving water quality, biodiversity and soil - and a strengthening, more resilient economy. CITATION:Hazell, P, Wilson, C and Hall, C, 2018. Landscape regeneration lessons learned from Mulloon Creek, in Proceedings Life-of-Mine 2018, pp 125–126 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

To provide safer and more efficient mine operations by improving the operational performance of underground trolley line communication systems. Approach The dc trolley line provides a convenient means of In-mine communication since it can carry signals to each phone on the system whether the phones are in mine vehicles or in a fixed location such as that of a dispatcher. In many cases, however, the system does not perform satisfactorily. Short communication range, noise, and dead spots commonly interfere with effective communication. These problems are inherent with the trolley line, which was designed to transmit power and not communication Signals. As a power line, the trolley line is connected to rectifiers and feeds many loads such as motors, water pumps, track block lights, etc. Each of these devices represents a low impedance radio frequency (RF) shunt that seriously reduces carrier communication Signals. Performance is therefore often poor and can be improved only if the effects of the various shunts can be reduced. The Bureau of Mines has developed numerous methods applicable to either existing or planned phone systems which can improve communication range and reduce the shunting effects of the various loads.

Jan 1, 1983

Validation and Simulation of Optimised Compressive Crushing Ores and aggregates are used in countless applications all around in the society. The frequent and escalating usage of these natural resources requires efforts aimed at not only making do with what is available, but also undertaking actions to improve the production yield and the processes involved. This strive to improve the performance and efficiency of existing crushers and crushing processes has brought about research concerning optimisation of crushing plants as well as theoretical optimisation of crushing. Previous work shows that different applications and different materials require different compressive crushing in order to accomplish a theoretically optimal size distribution. These optimisation results, obtained by genetic evolutionary algorithms and evaluated with so called fitness functions, convey the theoretically optimal number of compressions and their corresponding compression ratios. Presented in this paper are thus some laboratory crushing tests, which are conducted in order to validate a set of previously optimised crushing sequences. More specifically, interparticle crushing sequences are carried out in a Piston-die testing equipment, where samples are sieved between each compression. The subsequent analysis of these results shows good correlation with model predictions, which combined with a comparative study between presented optimisation results and measured data from a real crusher indicate a significant potential for improvement. However, before redesigning crushers according to what is theoretically optimal, the resulting impact as well as the effects on the outcome of a crushing plant must be examined. Crushing plant simulations using the software PlantDesigner« are consequently performed. Models of existing crushers are altered, resulting in changed particle size distributions from some of the crushers in a crushing plant. Thence, it is concluded that significant gains can be made in terms of capacity, process yield and energy consumption.

Sep 13, 2010

By J. E. Nesset, S. R. Rao, J. A. Finch

"For base metal sulphides, iron rejection starts in mineral processing. This review focuses on changes in plant practice specifically to improve iron sulphide rejection by control of contaminant ion effects and discusses selected general innovations in mineral processing that can be expected to play a role. One group of changes to control contaminant ions is in size reduction (the use of stage grinding and inert stirred milling) and another is in system chemistry (order of reagent addition and exploitation of the flexibility of sulphoxy reagents). Plant examples illustrate the successes, indicating that there are several options available. The general innovations start by considering the new tools for measuring gas dispersion properties and quantifying froth characteristics by imaging. Examples of their application to improve concentrate quality illustrate the potential. Other innovations stress adapting geostatistics to model variation in milling and flotation response to provide feed forward control and rigorous application of statistical experimental methodology in plant test work. An example from one concentrator shows improvements in concentrate quality from application of basic principles can be impressive.INTRODUCTIONThe more iron control (rejection) that can be accomplished in mineral processing the lower the subsequent metal extraction costs and environmental implications of iron disposal, particularly in hydrometallurgical processes. Iron rejection has been a contributing target to periodic attempts to apply mineral processing to nickel laterites and bauxites but the prime application is control of pyrite and pyrrhotite (iron sulphides) in the treatment of sulphide ores by flotation. In this paper some new concepts and innovations introduced in sulphide flotation plants over the past ten years or so (i.e., since a previous review [1]) will be outlined with examples of how they have contributed to improved “iron control”.To increase rejection of iron minerals, first the recovery mechanism should be understood. There are four principal ones, two physical in origin: 1, via locked particles (i.e., flotation of composite particles due to insufficient size reduction to liberate the minerals) and 2, through entrainment in the water reporting to the float product (an unselective process); and two originating from a response to the system chemistry: 1, true flotation (i.e., iron sulphides becoming hydrophobic) and 2, as a result of iron sulphides forming aggregates with hydrophobic particles (e.g., ”slime” coatings). There has been considerable effort to diagnose which of these dominates iron sulphide recovery; in many cases it is due to “chemistry”, in particular true flotation. The flotation effect often appears related to contamination by metal ions [1]. This can reduce selectivity in two ways: 1, metal ion species may activate iron sulphides, or 2, cause general depression which demands more vigorous flotation conditions (e.g., additional collector) with consequent loss of selectivity. This is where the review will start, by considering ways to control contaminant ions."

Jan 1, 2007

By P. C. Schutte, J. R. Smith

The objective of ergonomics is to enhance the effectiveness and efficiency with which human tasks are carried out. Furthermore, the objective is to improve desirable human values. This can be achieved by enhancing safety, reducing fatigue and stress, increasing comfort, increasing job satisfaction, having greater user acceptance and thereby improving the quality of life. Mechanization has influenced the prevalence of injury, mainly due to the application of human physical effort as the power source. With mechanization, the operator’s function is now essentially one of control rather than being an energy source, however the risk of injury has not diminished. Mechanization in itself has introduced inefficiencies, health risks and physiological stress. The major objectives of ergonomics are discussed through examples of acceptable and less successful implementation of ergonomics within mechanized mining. The influence of the machine system on the human is addressed and practical solutions to improve and optimize the interaction of the human and the machine are outlined. Furthermore, practical examples of control and display integration, anthropometric and biomechanic influences on design, orientation, posture and stereotypes are used to accentuate the advantages of the application of sound ergonomics principles to the specialised area of mechanized mining.

Sep 1, 2001

By Varadajan Seshadri

Kambara Reactor (KR) consists of a ladle where pig iron is stirred by an impeller during addition of a flux powder. The objective is to improve agitation leading to dispersion, of the flux powder, in the molten pig iron in order to improve desulfurization of the liquid melt by improving solid liquid interaction. The life of the impeller is limited as it is subjected to abrasion at high temperatures. The shape and design of the impeller also has an effect on the performance of this reactor. A 1:7 scale cold model of a KR unit of the Companhia Siderurgica de Tuberao ,one of the integrated steel plants in Brazil was constructed in order to evaluate the mixing and mass transfer conditions. Mixing efficiency was investigated by tracer additions and subsequent measurement of conductivity. Mass transfer in the reactor was assessed through iodine transfer between water and kerosene and employing a macroscopic model. Mixing depends on impeller shape and depth of immersion The role of dispersion is highlighted by faster kinetics when impeller velocity is increased. The results enable assessment of design aspects of the impeller on the process.

Jan 1, 2006

By R. S. Burns, J. G. Erskine

The performance of the nine 5.5 m diameter x 6.4 m mills (18 x 21 ft) initially installed at Bougainville Copper Ltd. did not meet the laboratory and pilot plant derived design expectations as measured by Bond Work Index. During the post-commissioning period, inefficient grinding of coarse material resulted in a build-up of large circulating loads and led to reduced throughputs because of pump and cyclone overloading. Installation of larger pumps and cyclones and development of an improved circuit control philosophy alleviated materials handling problems and permitted higher tonnages to be attained. Since 1977, plant throughput has been increased by installation of three additional mills. These are 0.9 m (2.9 ft) longer than the other nine and have a higher capacity. Developments in classification and mill speed-up, together with a finer ball mill feed size and substantial improvements to mill availability (99% in 1982) have further increased plant capacity. There is a continuing emphasis on improving grinding circuit efficiency in terms of throughput/grind. Current development work includes trials of graded ball charges, different liner profiles, and assessment of scalping/regrind proposals.

Jan 1, 1985

Supergene nickel sulphide ore mined currently by Agnew Mining Company is at times partially oxidised to sulphate. The resulting soluble nickel, and calcium and magnesium in mill water, are shown to act as depressants in flotation. The depressant effect is favourably selective in that violarite, the main nickel mineral, is less affected than pyrrhotite. Nickel recovery, however, is adversely affected, probably through reduced flotation of complex sulphides. Soda ash consumption is increased markedly by the presence of the cations as shown by operating data and pulp titration tests. A significant increase in concentrate grade, from 9% to 14% Ni, was achieved late in 1981. One of the changes in plant practice which contributed to this improvement was the addition of soda ash to mill feed rather than to flotation feed as before. It is shown by laboratory tests that this reduced the depressant effects of the cations, thereby improving recovery at the expense of rougher selectivity, or equivalently, increasing concentrate grade at constant recovery. The selective depressant effect cannot be exploited until scavenger recovery is improved and a scavenger concentrate regrind-retreat äcircuit is implemented. Development is

Jan 1, 1978

By D Nicoli, P Feltoe

The operation of grinding circuits are vital to the success of most mineral processing operations in the provision of effective size reduction whilst maximising throughput. However these same circuits, and especially semi-autogenous grinding (SAG) mills, are highly interactive with product re-circulations and long time delays. This makes the optimal control of these difficult by conventional controllers, such as PID, which generally places a heavy reliance upon operations for control. In order to account for the peculiarities (such as ore type changes) and the abnormal situations that continually beset these circuits, it is necessary to adapt linear control techniques to cater for these situations. The Honeywell Hi-Spec Solutions SmartGrindTM controller is a marriage of multivariable predictive control (MPC) with techniques that provide adaptation of the control to optimise the circuit under all conditions. Optimal control is achieved by incorporating pattern recognition techniques to detect and act on discrete events (eg ore type changes) and adaptation of the MPC to account for known process and equipment non-linearities. AlcoaÆs Wagerup Refinery is the first site worldwide to have this technology applied to the SAG milling circuits and this has resulted in throughput increases in excess of two per cent and significant improvements in circuit operations. This paper describes the implementation of the control to the refineryÆs Mill 3 bauxite grinding circuit and the capacity/operational improvements achieved thereof.

Jan 1, 2000

By H. D. Stolovitch, M. L. Lavallée

"An engineering system used to analyze and improve the performance of industrial grinding circuits has been adapted into a training program. The systematic approach to the design of training was applied in order to:Determine if training was an appropriate and effective tool for the transfer of this new technology;Define the technical content of the program;Establish program specifications based on learner and context characteristics;Design and test prototypes of the instructional modules; and,Establish a strategy for plant implementation and maintenance of the training program.This paper thus describes how a engineering system is transferred to the workplace through the use of designed instruction.INTRODUCTIONTraining can change human performance in a permanent way. It can improve productivity for the overall benefit of an operation. Organizations can therefore use training as a mean to achieve their specific goals. Training is not the solution to every performance problem. However, in many cases, it can be a very effective way to attain desired performance.The benefits of training are often difficult to assess. However, to remain competitive, organizations must introduce new products and innovative technologies. Often, they can do both most effectively through suitable training interventions.In order for the effort and investment of training to provide optimal results, two points of view should be adopted.• An overall view of the system in which training is to be applied.• A systematic approach to the design of training (Stolovitch and Keeps, 1989)."

Jan 1, 1992

By G. S. Headley

At the Sullivan Mine, recent experience with sulphide fires, locally referred to as " hot muck", has necessitated extensive modifications to pillar mining design and operating procedures. Potentially hot pillars are now being designed and mined to prevent fires. Unusual safety hazards and difficulties are encountered in working with, and adjacent. to, existing pillar fires. Operating procedures developed for these conditions have proved successful for safe and continuing production. These changes have minimized the impact of hot ore on current operations and have promise for an improved future.

Jan 1, 1977

By Henry L. Ehrlich

This survey compares bioleaching and biobeneficiation by autotrophic bacteria with that by heterotrophic bacteria and fungi Some physiological principles are reviewed. Advantages and disadvantages of autotrophic and heterotrophic leaching are discussed. Principles of anaerobic leaching by autotrophs and heterotrophs are introduced. and the advantages? over aerobic heterotrophic leaching are discussed. Examples of useful organisms in the autotrophic and heterotrophic categories are cited.

Jan 1, 1991

By AIME

Annual production of more than 4,000,000 tons of 0.74 percent copper ore and coincident handling of over 5,000,000 tons of waste at the open-pit mine of Castle Dome Copper Co. near Miami, Ariz. takes a lot of power. Manufacturers have ever co-operated with mining companies in providing the required equipment to suit the problem. Power equipment suppliers have done much to make possible the economic and profitable production of copper from low-grade ores. In the future, as mining operations will necessarily handle even lower-grade ores, the ability of the manufacturer to supply the power and mechanical equipment to produce more metal at a fair and reasonable price will be the good right arm of the miner. About 27,000 tons of concentrate is produced from the 4,000,000 tons of ore.

Jan 1, 1948

By Huang Qiming

The CISDI-GreenEAF innovatively applies the top-side-chute for charging for improving the cold zone of electric-arc furnace (EAF) requiring preheating scrap. It can greatly reduce the operating power consumption during EAF melting by combined use of fume for preheating scrap. The enclosed charging mode and specially-designed structure contribute to less emission of dust and fume during charging while enhancing the metal yield. Thanks to the extraordinary fume temperature control at scrap preheating procedure and fume quenching technology as developed by CISDI, for restraining the regeneration of dioxin.

Oct 30, 2017

By Demitri B. Shimkin

Minerals - A Key to Soviet Power, by Demitri B. Shimkin. Harvard University Press. $8.00, 452 pp., 1953. -The book is an economic evaluation of the position of the Soviet Union in respect to mineral wealth and development. Various sources are drawn upon, including the reports issued after completion of the various five year plans. The book is of considerable reference value despite the confusion which beclouds information concerning Soviet mineral progress. The theoretical study is the joint product of some of the staff of the Harvard University Russian Research Center. The author's approach to metals and nonmetals in the Soviet Union is systematic and he presents a great deal of data covering the period 1926 to 1950. Indicated weaknesses in the mineral economy are highlighted. Some considerable space is given to Soviet mineral future.

Jan 5, 1953