Search Documents

Hydrometallurgy has a history of over 300 years with copper leaching and cementation having been exploited in Spain as far back as 1670. Since then, hydrometallurgy has become an integral, expanding branch of extractive metallurgy. This paper reviews major developments in hydrometallurgy over the past century with emphasis on recent commercial developments and their impact on the mining and metals industries. The environment in which these developments has taken place has changed significantly in the past two decades and many factors, often non-technical, have emerged as constraints on the operation of existing plants and the expansion and development of new hydrometallurgical operations. Finally, a number of possible new developments that will shape the future of hydrometallurgy in the new millennium are discussed, particularly as they relate to the assimilation of technical advances in other areas of science and engineering. The impact of current trends in the education of hydrometallurgists and the provision of research in support of these future developments is also addressed.

Jan 1, 2000

By R Heath, P Rose, L Coetser

A sustained eight-year major research effort has been undertaken in South Africa to develop integrated passive water treatment systems for the sustainable removal of sulfates, while simultaneously addressing the removal of metals and acidity. The research effort addressed the problem both at a fundamental science level and at the more empirical pilot plant level. Whereas there are numerous anaerobic sulfate reducing reactors in operation on mine waters that remove some sulfate together with metals and acidity, these are typically plagued by low sulfate removal efficiency and gradual reductions in overall reactor efficiency with time. The South African research effort has focused on understanding the fundamental microbiological and biochemical reactions that occur in anaerobic reactors filled with lignocellulosic material and subjected to high sulfate water. Hypotheses have been developed that differentiate the reactions occurring in such a reactor into groups that should be individually optimised and these hypotheses have been verified through rigorous laboratory and pilot scale studies. The results of this research are incorporated into a patented multi-stage integrated passive treatment system that is capable of sustained high rate removal of sulfates, metals and acidity.

Jan 1, 2003

The major heavy industrial consumers of limestone are the cement, lime'and steel ind- ustries. Each of these requires large quantities of cheap raw material. Other ind- ustries such as glass and chemical manufactur- ing are significant consumers and agricultur- al and constructional activities provide additional demand which is usually more local in its occurrence. Limestone is widely dis- tributed throughout Australia but location in relation to major markets, and transport con- siderations render most deposits of no economic value. Among deposits which are sufficiently close to the major metropolitan markets many must be rejected as being unsuitable on grounds of quality, inadequate size for major.develop- ment, or other reasons such as environmental considerations. The major producing locations are sit- uated in a variety of geological environments. Most have limited reserves and require partic- ular attention to quality control. Planned extraction programmes based on detailed geo- logical investigations enable not only satis- factory grade control but also permit, by the adoption of appropriate quarry procedures, the use of sub-grade material, thus optimis- ing utilisation of the available reserves.

Jan 1, 1976

Mineral processing is at the hub of the exploration-mining-metals production system. Because of the large volumes of material processed, incremental technology investments can pay off better than for other parts of the system. However, much of mineral processing remains a 'black art', because we are behind in investing in modem technologies. Consequently, we have one of the best opportunities to improve efficiency and competitiveness through the application and transfer of technologies that have already been developed for other industries. The reluctance of minerals companies to place priority in our area is not because we lack new ideas; our senior management has not been convinced, based on our previous results, that such investments will pay off as well as other investment opportunities competing for the same resources. The key is the proper establishment of technology strategy and more effective transfer of technology. The presentation will identify the failure mechanisms of technology transfer and will present a model for improving the success rate, a prerequisite for raising the priority of mineral processing investment. Topics emphasised include strategy formulation, human resources planning, and total quality management principles applied to improving technology transfer.

Jan 1, 1993

Increasing attention is being focussed worldwide on the strategic environmental assessment of mining projects, including consideration of cumulative environmental effects. In New Zealand there is now an end in sight for inappropriate delays in resource consent approval of responsible mining projects. This paper investigates six case examples of recently consented mining and quarrying projects, whose applications were notified. It also explores the nature of delays that occurred, the factors that contributed to the delays, and whether the consent process delivered fair and effective public participation and desirable environmental outcomes.

Jan 1, 2005

By Miskelly N

In Australia and New Zealand, the 'Australasian Code for Reporting of Identified Mineral Resources and Ore Reserves', which was released by industry in 1989, is operating successfully in a co-operative approach between industry and regulatory authorities. Similar codes or guidelines exist or are under development in the United States of America, Canada, the United Kingdom and South Africa, although the regulatory backing given to the Australasian Code is unique. International standard definitions for Mineral Resources and Reserves, and for categories of Resources and Reserves, have been under development by the Council of Mining and Metallurgical Institutions since 1994 and have already stimulated considerable convergence of definitions and reporting standards in participating countries. It is hoped that agreement on this international standard for public reporting by mining companies will be reached within the next two years, and it is expected that adoption of the standard will result in a higher and more uniform quality of reporting worldwide, with a consequently greater interest on the part of the general public and financiers in investing in the mining industry.

Jan 1, 1997

Early efforts to control the dust necessarily produced during dry crushing operations, took the form of venturis at loading chutes and other places where dust was most evident. These venturis discharged to the atmosphere and for obvious reasons were not very satisfactory.Attempts to collect the dust drawn off by the venturis, using dry cyclones, were not successful, the cyclones catching only the coarser particles. Further, no satisfactory method of continuously discharging the dust catchment was evolved. Water sprays were also used, and will be referred to later.In 1940, a single discharge fan of 3,000-4,000 cu. ft. per minute capacity, was installed to draw the dust-laden air from the Symons crushers and ·screening sections with their attendant conveyors. Suction was through two 15 in. ducts which branched off into 10 off-takes situated over the conveyers at points of discharge from crushers and screens.A dry cyclone was installed in front of the fan, which exhausted into a bag-house.The cyclone suffered from the defects of the smaller units mentioned earlier. When the collected dust reached a certain level in the cone, no more collection would take place until the cone was emptied. This objectionable feature was overcome by introducing a jet of water ahead of the cyclone. The water and dust collected overflowed a weir and were pumped to the mill.

Jan 1, 1948

The beneficiation of heavy metal oxides, such as iron ore, is usually performed with heavy medium separation in cyclones, static baths and lately with Larcodems. Atomized ferrosilicon is most suitable as a heavy medium at densities above 3600 kg/m3 whereas a mixture of milled and atomized ferrosilicon is suitable at densities below 3600 kg/m3. When operating a beneficiation plant at densities higher than 3600 kg/m3 the quality of the ferrosilicon particles is an important factor that influences the control of the beneficiation process. Therefore, it is important to know how the rheology would be affected by the ferrosilicon quality as it also influences the control of the process at these elevated densities.

Jan 1, 2002

The writers of these notes, having conducted some tests on the steam consumption of air compressors under varying conditions, believe that the detailed results of such tests will be of interest to the members of the Institute, and may lead to the contribution of further and more valuable information, of benefit both to manufacturers and users of this class of machinery-to the manufacturer in that he frequently has the opportunity of giving a very thorough test to the machine in the shop, and-tothe user or purchaser by making clear to him what may be reasonably demanded of a high-class machine. It must be remembered that, though of the highest importance, a low steam consumption is but one of the many features of a high-classmachine; for the present, however, it has been considered advisable to confine the paper chiefly to the first-mentioned aspect, with such information concerning the air ends as is obtained along with the steam consumption tests. Unfortunately, too few of these tests are conducted, and but few results are published, therefore the writers feel that no apology is needed in bringing their results before the members.Some nine months ago the Brilliant Extended G. M. Co. was supplied with a compressor by Messrs. Thompson and Co., of Castlemaine, and with the object of testing its actual performance.

Jan 1, 1907

By R Lastra

Applied mineralogy involves conducting investigations on ores, minerals and materials to solve problems encountered in mining, metallurgy, processing, industrial minerals, environment, health and other fields. The investigations are performed to determine the mineral behaviours during processing by using every mineral and ore characterisation technique and appropriate instruments. As the field is young, new techniques and instruments are still being developed. This paper attempts to convey the scope of the field by:describing the capabilities of the respective research instruments for determining mineral characteristics, summarising investigations of gold as an example of applied mineralogy studies of precious metals, andpresenting a case history where applied mineralogists worked closely with mineral processing engineers on a base metal ore and mill products to help the engineers optimise their processes for maximum recoveries.

Jan 1, 2008

By A Ruotsalainen

Mining industry sees a comprehensive future in optimisation and process control. High resource utilisation is a starting platform when lower operational costs with higher rate of return are the target. Simulation is quickly penetrating the mining industry as a planning tool. A discrete event simulation helps to visualise the reality of a mine and the various mining processes, which typically include a fair degree of complexity. What-if scenarios can help to determine the impact of occurring changes to production. Understanding of critical points in the layout and resource allocation at an early stage can help to optimise the material flow. The obtained information may then be used as proposal or confirmation of the system applicability and economy. Simulation is a way to fine-tune and optimise the resources within. It helps to predict system sensitivity to various aspects. Although simulation today is used typically in a feasibility stage, there is an opportunity to continue using simulation for further process enhancement. In the future simulation will without doubt be used increasingly as a dynamic simulation and continuous improvement tool. This paper discusses the use of OptimineÖ simulation tool in resource optimisation. Some examples describe the way the tool operates and how it helps to view the technology, mine layout and operational data.

Jan 1, 2003

By K Uchino, M Inoue

Self-potential anomalies are generated by fluid pressure gradient, by temperature gradient or by chemical gradient. On the basis of this principle, a new technique is proposed to locate the fire source of spontaneous combustion of coal by the self-potential method. In order to investigate whether this method can be applied to locate the spontaneous combustion of coal in practice, surveys of self-potential distributions were undertaken in a coal waste pile undergoing spontaneous combustion. The results showed that there is a negative centre of the electrical potential distribution in the measurement area. The potential in this centre is about 140 mV lower than that in the surrounding area. Moreover, the negative centre of electrical potential distribution almost overlaps with the high temperature zone. Therefore, it is concluded that it is possible to locate the heat source by the measurement of self-potential distribution.

Jan 1, 2005

By M McCarthy

Attraction, recruitment and retention of quality mining engineers is becoming increasingly difficult for many mining companies. Part of the problem is attracting young professionals, especially given the decline in graduating engineer numbers, and the other is balancing the new engineerÆs development with business needs. The evolution of the graduate program at Olympic Dam over the last five years has resulted in substantial benefits for both the engineer and the company. The program has developed to provide structured exposure to key areas of the mine enabling new engineers to step into vacated roles as the need arises. The pool of quality engineers generated by the graduate program is a buffer against high industry turnover and helps reduce future recruitment expenditure. Olympic DamÆs program goes beyond conventional recruitment of graduate engineers. Innovations designed to improve intake include the employment of graduate engineers as well as final year students, retraining of existing personnel from other backgrounds and fast track recruitment for previous vacation students. By employing a cross-section of professionals to complement the generic university graduate, the company takes full advantage of the relevant lifestyle experience belonging to the individual, which is a substantial factor in turnover. Study assistance and a salary paid for final year students and mature age students often creates a loyalty that lasts beyond graduation. Careful selection of vacation students increases the ease of recruitment at a later stage and ensures that full advantage is taken of the relationship developed previously between the company and young professional. The evolution of recruitment at Olympic Dam has seen a decline in the turnover statistics of young mining professionals.

Jan 1, 2005

By T A. Helms, P Gottlieb, S E, R Bateman

In response to the ever-increasing challenges facing the modern gold mining industry and the need for improved gold recoveries within all processing streams, CSIRO has upgraded its latest automated mineralogical analysis system, QemSCAN (formerly QEM*SEM), with special purpose hardware that speeds up the location and measurement of precious metal-bearing phases. By rapidly scanning the surface of polished blocks, and accepting only fields that contain the minerals of interest, QemSCAN is able to find, map, and quantify target minerals in extreme detail. Phase identification and quantification is achieved by placing a grid of points over the target particle and collecting X-ray information at each analysis point. The resulting mineral maps provide the metallurgist with a complete textural description of all gold-bearing phases within the product measured, together with quantification of the gold phases in terms of their modal abundance, particle size, mineral associations, relative contributions to gold deportment and liberation characteristics. Examples are presented which illustrate how QemSCAN is able to find and quantify gold-bearing phases within low-grade ores from the Super Pit, Kalgoorlie. This work is the result of a collaborative project between Kalgoorlie Consolidated Gold Mines (KCGM), CSIRO Minerals, and the University of Queensland, and is on-going.

Jan 1, 2000

By Royston D

Victoria has an extensive brown coal resource, 202,000 Mt, of which 43,300 Mt is regarded as readily recoverable. This brown coal is located principally in the Latrobe Valley as thick seams and is being extracted at low cost primarily to support base-load electrical power generation. The high moisture content of the coal is partially off-set in many applications by the high reactivity of the coal and the generally low levels of potential pollutants such as ash, sulphur and nitrogen in the coal. Large scale development of this brown coal resource began in the 1920's. In addition to electricity generation, it is used for briquette production, carbonisation of briquettes to char and was gasified for town gas supply to Melbourne (1956 - 1969). The BCLV coal to oil pilot plant at Morwell is a major new initiative in the use of Victorian brown coal. Many other new developments are in place and emerging in the utilization of low rank coals. Examples of these developments are, the large-scale gasification of lignites in the USA, and value-added products such as bulk chars, solid fuels, activated carbons and coal-water mixtures. The Government of Victoria has created the Coal Corporation of Victoria to promote current sales of briquettes and to encourage further new industrial developments based on the State's brown coal resources, in particular the Loy Yang coalfield. The Coal Corporation also has a vigorous product and process oriented research and development Programme.

Jan 1, 1987

The Ausmelt Catalytic Waste Converter (CWC) has been developed for use in the treatment of industrial wastes and for the recycling of secondary materials. Ausmelt Technology uses a top submerged lance system within a versatile and efficient slag bath reactor. High temperature pyrometallurgical reactions are carefully controlled within an oxidised molten siliceous slag such that metals can be extracted from waste feedstock for recycling, with non-volatile elements reporting to the slag, usually as oxides. Modification of the slag chemistry results in a final slag product that is stable, vitrified and is able to pass standard leach tests such that it is safe to discard or be used in civil engineering applications. Toxic components in the wastes such as organohalides can be completely destroyed and are prevented from reforming. Waste to energy conversion is practiced by the addition of a heat exchanger/steam generator in the converter offgas system. The Ausmelt CWC has been used for recovering zinc from residues and slags, treating spent potliner (SPL) from the aluminium industry and a wide range of electronic and other potentially valuable waste materials. Methods of monitoring the exhaust gases at different stages in the CWC gas handling system are discussed. The assay of these gases prior to emission is used to assist in the control of the converter chemistry to ensure the complete oxidative breakdown of the feedstock.

Jan 1, 2002

By A Scott

Long before a modern mine commences operations it has already become a wealth of information. After start up, it can generate enormous quantities of data û especially with semi-automated data acquisition by instrumented mine equipment. However, much of this data is of limited use for evaluation of (potential) performance unless it links in some way to the site business model. An underlying reason for this waste of data is that the different cultures, financial, technical, community, environmental, etc not only have many areas of interest but also have very different conceptual models by which they evaluate performance. It is too ambitious to attempt to bring all of these cultures together û in a single step. However, the success of the Mine to MillTM project has demonstrated that substantial operational value can be added by using a more integrated approach to comminution. The next logical step is to integrate measurement and then to track performance from orebody model to saleable product and waste disposal. From resource to product also represents a path from very sparse, highly variable data to much more detailed measurement and more representative sampling. However, in both cases the data collected is strongly focused on the technical requirements û not on the business model. This paper considers how to define at least some of the key decision points in terms of some case studies. Performance data from many areas might be used to derive simple models which can then be used for forecasting and optimisation of planning.

Jan 1, 2002

By M Noppe, I Glacken

There are many critical nodes along the mine value chain, from orebody to mineral product, and inter-disciplinary input is required to analyse the variability and uncertainty at each node in order to identify and mitigate areas of risk. Mining differs from many other industries in that the variability in the product is dictated largely by the inherent nature of the input material (the orebody). The true characteristics, including the variability of the orebody, are never known exactly and are instead based on estimates derived from sample data. A further difference is that bottom-line gains are largely controlled by world commodity prices, which can vary with time, rather than by local supply and demand issues. Methods for identifying, reporting and responding to this inherently variable raw material are discussed. These include analytical and reporting methods, equipment and software, risk analysis and reality checks (eg reconciliation). Sampling results, mineral resource and ore reserve estimates and economic assumptions are a function of the variability of the orebody. Risk quantification should be expressed as a level of confidence, which takes into account the scale or period over which the risk is being assessed (life-of-mine, annual or shorter production periods) and should convey the likelihood, severity and consequence of occurrence of a given event. The future generation of mining specialists needs to understand the entire mine value chain to better manage risks and maximise mine dollar-value.

Jan 1, 2002

By H Han, X Wang, T Li, D Duan

"In this paper, the reduction and separation behaviour of iron and slag in carbon composite iron ore pellets has been investigated experimentally using an electric resistance furnace simulating a rotary hearth furnace process. The factors that affect the formation of iron nuggets, such as temperature, holding time, molecular ratio of C/O and basicity, are discussed. Results show that the reduction of iron ore, carburisation of reduced iron and the composition and quantity of slag are very important for producing iron nuggets. Through optimisation of process parameters, iron nuggets can be formed below 1300¦C when holding time is 20 minutes, C/O is 0.7 and basicity less than 0.5. This study provides a theoretical and technical basis for iron nugget production.CITATION:Duan, D, Han, H, Wang, X and Li, T, 2013. Iron nugget production technology in rotary hearth furnace process at lower temperature, in Proceedings Iron Ore 2013, pp 363-368 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 12, 2013

Mining of narrow vein mineralisation, invariably depending on the mining method selected, involves the extraction of both ore and waste rock. The level to which mining of waste rock can be minimised depends on numerous factors, but particularly the thickness and dip of the deposit. Resue mining is a method of mining that allows split face firing within stopes to allow waste and ore to be mined separately, allowing dilution to be minimised. This paper examines the technique of resue firing and its applicability to the mining of narrow vein deposits. Particular emphasis is placed on the conditions in which resue mining presents a suitable option for mining of narrow veins.

Jan 1, 2008