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By K Gottliebsen

Many hydrometallurgical and chemical processes produce large amounts of acid waste. This is illustrated by the copper S/X-E/W process used at the Mount Gordon mine in North Queensland, which produces a tank house bleed in the form of a concentrated sulphuric acid stream. The bleed stream is necessary to remove impurities such as iron that decrease the efficiency of the electrowinning process. However, this bleed stream comes at a high financial cost due to large quantities of make up sulphuric acid required as well as the need to neutralise the bleed stream prior to disposal. The present work describes the approach taken to develop a solvent extraction process for the selective recovery of sulphuric acid from copper tank house bleed liquor. The proposed extraction system was investigated using a branched long chain aliphatic tertiary amine tris(2-ethylhexyl)amine (TEHA) as the extractant, Shellsol 2046 as the diluent and octanol as a modifier. Computer simulations were used to determine the optimum operating conditions for the recovery process. It was found that the process was able to selectively recover up to 90 per cent of the sulphuric acid from the copper electrolyte. This is recovered as a pure aqueous acid stream at a concentration of up to 130 g/L that can be recycled back into the tank house circuit or other areas of the process. The raffinate acid concentration was reduced from 180 g/L to as low as 18 g/L, significantly reducing waste disposal and the environmental impact of the copper process. The equilibrium data and simulation results were also compared with an alternative extractant, CYANEXR 923. Finally the efficiency of the TEHA extraction system was investigated on a pilot-scale in a pulsed perforated plate column. This information was used in order to scale the process for an industrial application. The same methodology applied in this case study could be used to provide innovative and cost-effective solutions to waste streams encountered in other hydrometallurgical or chemical processes.

Jan 1, 2000

By R H. Yoon, M Gupta, A Noble, K Huang

Froth flotation is the most commonly used separation technology in the mineral industries. Given the complexity of the pulp and froth phases as well as the multitude of operational parameters that influence flotation performance, purely fundamental models with strong predictive capacity are limited. As a result, accurately modelling modifications to an existing flotation circuit are challenging, particularly when using empirically-derived models from a different operating configuration. Despite these complexities, a recent publication by the authors (Huang et al, 2022) has shown that flotation rates can be accurately predicted from a first-principles model that incorporates hydrodynamic parameters (eg pulp density, superficial gas velocity, feed flow rates etc), surface chemistry parameters (eg contact angle, zeta potentials and surface tension), and size-by-class liberation data. Circuit simulations using this model were shown to be effective in predicting experimental graderecovery curves from the size-by-class mineral liberation matrix. Since the model is derived from fundamental characteristics of the flotation system, it can be used to simulate alternative circuit configurations with varying degrees of recycle. Conventional flotation circuits are operated in a closed-circuit configuration by routing the cleaner scavenger tails (CST) back to the rougher feed to provide an additional opportunity to recover the slow-floating particles. This widely-used flotation strategy has been under constant debate, and several researchers have provided evidence that open circuit configurations provide higher separation and better circuit control (Konigsman, 1985; Bulatovic et al, 1998; Thompson, 2016). Recently, Finch and Tan (2021), used linear circuit analysis to show that open circuit configurations have a fundamental advantage when stage recoveries are high. Given the limitations of these prior studies, the objective of the current work is to further evaluate the merits of the open circuit configuration through a detailed circuit analysis and simulation study incorporating the first principles model described above.

Aug 24, 2022

Mere recognition of the need for technic- ally strong human resources in the'extractive metallurgical industries has not prevented the decline in the education base for broad spec- trum metallurgists. The ability of chemical engineers to perform very effectively in many extractive metallurgical positions does not remove from the need for a general metallurgic- al education system. The intrusion of chemical engineers into extractive metallurgy is only symptomatic of the problems facing the minerals industry and its educators. The prospect of a career in the minerals base industries is unattractive to potential students by virtue of perceived inadequacies in the professional basis of the industry and ignorance of its sig- nificance to Australia's future, as assisted by excessive secrecy and a low profile public Image.

Jan 1, 1987

Examples are given of the different management approaches used to improve a mine's profitability and the view is put that attention to mine design is very important but easily overlooked. The need for humans to use graphics to ccanprehend and develop strategies to exploit ore deposits is discussed. The use of two and three dimensional representations for geology, mine design and survey data is reviewed. The current use of computers in mining is discussed and reasons for the limited use of ccanputer graphis are proposed. Suggestions are made as to how more extensive use may be made of catputer graphics in mining by using recent and possibly forthcoming advances in computer hardware and by adopting certain software approaches.

Jan 1, 1983

A computer programming language known as GPSS is described and possible applications for the mining engineer are presented. The language is continually being upgraded with improved versions appearing about every three years. The tremendous power of the language is considered by comparing it with standard engineering programming languages, such as Fortran or Basic. Sample problems that can be solved using the language are indicated. The advantages and disadvantages of the languages are also discussed.

Jan 1, 1987

Best practice in environmental performance is a principle now increasingly and rapidly transferred around the globe. This matches both the greater rigour of environmental standards and the growing uniformity and `internationalisation' of standards for environmental management. There is no difference in the application of Normandy's environmental policy anywhere in the world.Normandy Mining is developing an Environmental Management System (EMS) which will satisfy:ò the need for technical excellence and best practice;ò the need to demonstrate `due diligence' in any jurisdiction;ò the need for financial statements and for insurance to reflect real world requirements for management of risk and liability.

Jan 1, 1997

By Ryan CG, Cousens DR, Suter GF, Griffin WL

A novel method utilizing PIXE with microbeams following fire-assay has been developed to determine PGE and Au at sub-ppm levels suitable for application in exploration. Analyses of the prills from the lead and silver fire-assay yield Pt, Pd and Au concentrations readily. NiS must be used as collector if the complete suite of PGE is required, but this method is not as Convenient.

Jan 1, 1989

The competitiveness and future growth of the Australian mineral resources industry face a number of challenges. The paper addresses key factors likely to influence the attainment of high performance and continuous improvement including organisational leadership, management/employee relations, technology, safety, health and the environment. Business practices such as benchmarking, Total Quality Management and re-engineering to achieve process and performance improvements are commented on. Future success for the industry will largely hinge on global business skills, a sustained focus on Quality principles and achieving performance through people.

Jan 1, 1997

By Masters I. M, Ozberk E, Chalkley M. E

The integration of iron rejection as hematite with the Sherritt two-stage zinc pressure leach process has been investigated on the laboratory scale. The two-stage pressure leach process is applicable for a greenfield zinc plant, or for replacement of the conventional roast-leach circuit in an existing zinc plant. An excess of zinc concentrate is used to accomplish acid neutralisation in the first stage of pressure leaching, and the residual concentrate in the first stage residue is treated with an excess of acid solution in the second stage of pressure leaching to yield high zinc extraction. Integration of hematite precipitation with this process allows for the potential sale of the iron residue, greatly decreasing the residue disposal problem. Two flowsheets containing the desirable features of both of these processes are described in this paper, along with laboratory Results.

Jan 1, 1993

The Western Australian Mining and Petroleum Research Institute (WAMPRI) was established in 1981 by the Western Australian Government as a funding and co-ordinating Institute to foster research into the mining and petroleum industry within this State. To June 1984, the Institute has sponsored 34 projects with a total notional value of $2.5 million and an actual cash commitment of $1.5 million. Strong support for WAMPRI has come from Industry with 60 companies contributing half the money needed for the research grants.The 34 WAMPRI projects funded so far cover all aspects of the mining and petroleum geosciences.Several WAMPRI projects are concerned with gold including processing technology and the development of exploration models and techniques, they are providing successful results.Although well supported by Industry there is a surprising lack of applications being submitted to the Institute in the area of mining engineering, where it is felt there is much scope for research projects.

Jan 1, 1984

By Lane G

This paper addresses project commissioning, that is, activities that culminate in the transfer of a project from the construction phase to routine plant operation. These activities should be initiated early in the engineering and design phase to ensure that the plant design is operator friendly and that construction is scheduled such that pre-operational testing and hand over to the owner occurs in a timely and cost-effective manner. For the purposes of this paper, commissioning includes all activities related to pre-operational testing, no-load testing, water commissioning, and ore commissioning. That is, all activities from construction completion to practical completion of the prime contract. This process is facilitated in numerous ways dependent on the nature of the project prime contract and the size of the project. For small lump sum projects, the contractor's responsibility may include all phases of commissioning to practical completion, whereas, a managing contractor on a complex multi-contract project may only be required to bring the project to mechanical completion and hand over to the owner for ore commissioning. Irrespective of the responsibilities, commissioning programs require careful planning, effective communication and detailed reporting. Unsuccessful

Jan 1, 1997

By Rawlings C. D

An assessment is made of the potential for thick seam underground mining of black coal in Australia. A brief summary is given of the geomechanical environment and previous mining history existing in a number of areas of particular interest from the point of view of thick seam mining. A classification of thick seam mining methods is presented with emphasis on the critical geomechanical para- meters influencing the performance of such methods. A summary is made of perceived geomechanical research requirements related to thick seam mining in Australian coalfields.

Jan 1, 1980

INDEX OF CONTENTSIntroduction.Systems of classification of coals.RankClassification of Australian coals.Defects of systems in use in other countries.Indexing by Fuel Ratio.Classification by Ultimate Carbon/Ultimate Hydrogen.Relationship between Fuel Ratio and ultimate composition.Suggested convention for classification.Origin and Evolution.Notes on directions of change of composition on Carbon Hydrogen chart.Summary and conclusion.Acknowledgments.Bibliography.Appendix.

Jan 1, 1948

The growth in the nickel market and the price increases predicted in 1970 have not mat-erialized. Several plants have been construct-ed, particularly to treat lateritic ores. A spectacular increase in cost of energy and the escalation of capital costs have led to severe economic difficulties on the part of many nickel producers. Several of the nickel prod-ucers joined together to form a Nickel Develop-ment Institute in 1984 with the prime objective of improving nickel markets. Most producers have taken exceptional action to cut overall costs as well as unit costs. Another organiz-ation made up of nickel producers, NiPERA, was established in 1980, to study and take action on problems of nickel in the environment and especially in the workplace.Ion exchange, and particularly continuous ion exchange, has been developed into a reli-able commercial unit operation in the last dec-ade. An example of how ion exchange combined with hydrogen reduction can be integrated into a Caron type reduction roast ammonium carbonate leach process for the recovery of nickel from laterites is discussed.

Jan 1, 1985

By Simes C. D

Results of experiments for dissolution of zinc by aeration of sphalerite in glass, copper, galvanised iron and stainless steel vessels of identical dimensions are reported. It was found that in a glass container dissolution of zinc reaches a maximum after 30 min aeration and then decreases whereas in the copper container dissolution remains nearly unchanged up to 30 min aeration and then increases. In the cases of galvanised iron and stainless steel containers zinc dissolution increased steadily with time up to 60 min aeration. It is suggested that the different rates of dissolution in glass and copper containers may be due to electro-chemical actions.

Jan 1, 1984

In recent years, wide consideration has had to be given to methods of improving the condition of the mine environment in many coal mines, and significant developments and changes have evolved. Thus even after substantial increases inòair flow rates at the working place (they have increased over three fold in the last generation), environmental conditions have arisen for which it has been necessary to introduce or consider: i) additional ameliorative measures, such as good housekeeping; ii) layout changes: such as Y or Z layouts; iii) homotropal ventilation; and iv) air conditioning. In certain countries, consideration has been given also to: v) additional payments reduced working times; vi) heat acclimatisation programmes; and vii) the use of cold or cooling suits At many hot and humid mines, the principal benefits from adopting (i), (ii) and (iii) have already been realised. At such mines,

Jan 1, 1983

The basic principles of mineral valuation were recognised and propounded at the beginning of this century and have remained virtually unchanged since then. Valuation is seen as a two part process commencing with a technical examination of the mineral property followed by a manipulation of the results of the technical examination in order to determine the monetary value of the project. A thorough and competent technical examination was seen then and remains now as the essential but not sufficient foundation for reliable valuation. All authors stressed the need to maintain the integrity of the data base and to ensure adequate coverage of all relevant aspects. The monetary valuation process through most of the first half of this century was mainly based on the Hoskold two rate method, derived from the formulae for valuing annuities but modified to provide explicitly for recovery of capital. Though the basic principles of valuation have not changed significantly, the means of implementing the components of the technical examination, the styles of deposits being evaluated and the mechanisms of monetary valuation have changed dramatically. Despite all the technological improvements, however, mineral valuations are still as apt to vary from realised performance as at any time in the past. As well, mineral property valuations are now being extended to cover all assets of potential value, including valuation of exploration tenements with or without identified resources. Valuation of exploration tenements will continue to be one of the most difficult and contentious of valuation tasks.

Jan 1, 1994

By Somerville M, Muray A, Bocking M

Australia has an extremely large total hot dry rock (HDR) resource above a depth of 5 km, equivalent to 7500 times its present annual energy consumption, of which 80 per cent underlies the Great Artesian Basin. The resources most likely to be exploited first are those residing in homogeneous granitic bodies beneath sedimentary basins containing insulating rocks such as shales and coal measures. In the Sydney Basin south of Muswellbrook, an area of high geothermal gradient corresponds to a gravity low thought to be a buried granite body at a temperature of possibly 250¦C. This locality is suspected to have the ideal geological characteristics for Australia's first hot rock test facility. Australia's high HDR potential is possibly unique in the world, in that the potential sites satisfy four independent, geological conditions, each considered as favourable for the creation of a resource, and for the ease of extracting that resource. They are: ò Higher crustal heat generating capacity than that of normal continental crust. ò Much of the Australian continent is covered by sedimentary basins which contain a high proportion of shales and coal measures that have low thermal conductivities, thus providing an insulating blanket for the heat being generated beneath. ò The sedimentary basins are in many places underlain by large untectonised granitic bodies that are not only a major contributor to heat generation, but also ideally suited to the establishment of HDR reservoirs. ò The crustal shortening stress field that is found in the majority of the Australian continental crust results in a vertical minimum principal stress orientation which should result in the development of favourably oriented horizontal stimulation cells necessary for maximising an HDR resource.

Jan 1, 1995

George Fisher Mine, near Mount Isa in northwest Queensland, has been producing Pb-Zn-Ag ore since the late 1980s. It consists of two separate underground deposits, George Fisher South and George Fisher North. These two deposits are drilled and modelled separately but are crushed and hoisted as a single stream. The Pb-Zn concentrator in Mount Isa processes ore from George Fisher Mine and Black Star Open Cut, with production also from the Isa Lead Mine until January 2006. This paper outlines the steps involved in setting up a robust reconciliation system for George Fisher Mine, in conjunction with requirements of the Pb-Zn concentrator, Black Star Open Cut Mine and the Mount Isa Lead Mine. Good quality input data and commitment to training have contributed to establishing a robust and effective reconciliation system. Reconciliation data has highlighted several other continuous improvement opportunities.

Jan 1, 2006

Agitation leaching data has generally not been analysed to extract the maximum amount of information that is available. Analysis of heap leaching systems has been developing over the last five years to include the underlying rate determining process. This has been found to be diffusion control for all copper leaching; irrespective of whether they are oxide or sulfide minerals. Extension of the diffusion model has enabled better scale-up protocols to be developed. Acid consumption in copper heap leaching operations has been found to be a first-order chemical controlled system. The analysis of the data is relatively straightforward. However the interpretation and scale-up is not as direct as for agitation leaching. The differences in the residence time distributions (RTDs) are required to properly account for the scale-up between test columns and field. The leaching of oxide copper in agitated systems has also been found to be diffusion controlled. However, there are significant differences in the control mechanisms. Initially the leaching control is the supply of acid to the mineral surface. This is limited by the diffusion through the surface boundary layer and is thus subject to the level of agitation. Higher agitation provides thinner boundary layers and faster diffusion rates. Similarly, higher grade material creates a thicker concentration boundary layer and relatively slower leaching. Acid consumption in agitated leach systems is also a first-order system. However, the interpretation of the RTD is easier from batch testing to continuous multiple CSTR series plant operations. Altering the method of acid delivery can significantly reduce acid consumption rates. Predilution of the acid minimises the local acid concentration near the addition point and can reduce the consumption by up to 50 per cent. Modelling of the combined leach rate(s) and acid consumption rates in agitated systems allows comparison of various leaching strategies and selection of the most appropriate. Similarly, the model allows the identification of economic limits to leach recovery; where the cost of acid consumption is greater than the value of the copper recovered. From this analysis selection of residence times for agitation leaching can be determined. The modelling tools are useful in identifying optimum conditions for the leaching process.

Jan 1, 2005