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By Mackenzie J. M W

The mechanism of clay slime flocculation in coal washing circuits is considered and it is concluded that polymer flocculants are most suitable. It was found that the addition of sea water with a polymer flocculant improved flocculation and settling, and it was also found that dilution of a flocculated pulp increased floc size and hence settling rate.In predicting plant consumption of reagent it was found that cylinder tests, or even pilot plant tests, could give erroneous results, particularly on flocculated pulps. Different flocculants may, however, be compared in cylinder tests.For filtration, flocculation with Separan plus sea water was much more beneficial than flocculation with Separan alone.INTRODUCTIONDuring the mining of coal, and its subsequent beneficiation by washing, large quantities of minus 10 mesh material are produced. This fine material, which consists of broken down shales and fine coal, causes difficulties in water clarification circuits, in refuse disposal, and in filtration of fine coal.These difficulties can be largely overcome by flocculation, and this paper discusses the mechanism of flocculation, the methods by which a selection of flocculant may be made from the large number available, and the limitation of the prediction of plant performance from laboratory tests. This work applies particularly to the washeries of The Broken Hill Proprietary Co. Ltd. (B.H.P.) and Australian Iron and Steel Ltd. (A.I. & S.) .

Jan 1, 1962

This paper is a tribute to the late Dr Donald Martin Hausen as a father of applied mineralogy. His dedication to promoting the field through technical societies and through his professional work was outstanding, and his activities as a humanitarian are noteworthy. Dr HausenÆs involvement in technical societies included organising and conducting the only ICAM congress that was held in the USA, co-founding and nurturing the Process Mineralogy Committee within the American Institute of Mining, Metallurgy and Petroleum Engineers, and participating in CAM, the International Mineral Processing Congress, as well as other technical societies. The Process Mineralogy Committee that he co-founded has continuously organised annual meetings in the USA by conducting a series of sessions, and 17 books on the proceedings from those sessions have been published. As an applied mineralogist Dr Hausen solved many problems in exploitation and processing of minerals, metals and materials, especially gold. He helped to find many Carlin-type gold orebodies by outlining targets using alteration halos as determined by X-ray diffractometry, and he defined mineral characteristics that affected gold metallurgy and cyanidation. It is also noteworthy that Dr Hausen and his wife, Mary, opened their arms and home to many foster children and were instrumental in their placement in many homes. They also sponsored refugees from south-east Asia, taught them English, housed them, and provided constant support until the refugees became responsible and independent US citizens.

Jan 1, 2008

Investigations into the flotation behaviour of single minerals, mineral mixtures and ores at the CSIRO Division of Mineral and Process Engineering have led to the development of sophisticated laboratory flotation testing equipment. Both routine and complicated flotation investigations can be conducted in a precise and reproducible manner using procedures and equipment that have been refined over many years of conducting careful batch flotation testwork. Several important advances in flotation research can be attributed to changes in testing procedure developed as a consequence of the availability of this equipment. The flotation cell and ancillary equipment is described and associated developments and techniques discussed.

Jan 1, 1992

In looking towards 2000, it is more than appropriate that we look back on the history of diamond drilling to give us a better understanding of where we have come from and see the significant advances that have been made.

Jan 1, 1992

By A J. Moore

The Australian Coal Association Research Program (ACARP) funded project, No C14057, entitled æEffect of Blasting on InfrastructureÆ, has been carried out with the objectives of providing methodologies for the assessment of the strength of infrastructure types and the establishment of responsible and realistic limits. Personnel from Melbourne, Newcastle and Swinburne Universities and Terrock Consulting Engineers conducted the project. Infrastructure types including: conveyors; power transmission towers; wooden power poles; electrical substations; pipelines, bridges; public access roads and underground workings have been investigated by both field studies and structural analysis. Railways, underground telecom cables, dams and industrial buildings have been reviewed using general structural analysis. This paper has been prepared for the mining industry to provide a progress report on the project.

Jan 1, 2007

By Millen M. J, Rainey S, Sowerby B. D

The control of size reduction in grinding machines and circuits may be enhanced by a continuous and accurate measurement of the particle size of solids in appropriate process streams. This paper presents a brief review of commercial particle s

Jan 1, 1997

By Hayes P. C

The kinetics of reduction of PbO-silicate melts in CO-N gas mixtures at 900¦C have been studied. Rea~tion rates were measured by moni- toring the CO2 content of the product gas. A wide range of gas and melt compositions and gas flowrates have been investigated. The overall reaction rates in heterogen- eous systems are typically characterised by a steady increase as the gas flowrate is in- creased. At low flowrates the processes are limited by gas film mass transfer. At high flowrates it is expected that the rates will tend to maximum values determined by either the rate limiting chemical reaction or diffusion in the condensed phase. In the present series of experiments it has been found that for any given gas composition the overall reduction rate goes through a maximum with increasing gas flow. The maxima, which occur at relatively low gas flows, are more than an order of magni- tude greater than those observed at high gas flowrates. The results of these and other experiments are presented and analysed. Possible rate limiting mechanisms in the reaction system and their implications regarding commercial reactors are discussed.

Jan 1, 1987

By Happ J. V

Factors affecting the rate of arsenic removal from lead bullion during softening processes were studied. Very high rates of removal could be obtained under conditions of intense agitation and ready availability of oxidant. Reaction mechanisms were proposed to explain the sequences observed. Selective removal of arsenic with minimal loss of antimony from bullion was favoured by a low temperature Harris process and oxidizing via a caustic soda medium.

Jan 1, 1987

By A Williamson

The New South Wales Department of Mineral Resources objective is to use data and information to undertake a detailed analysis of incidents and accidents to identify risks so that the predictable can be foreseen and avoided. The Department of Mineral Resources has established a computerised database called COMET (COmmon Mines EnvironmenT) to capture information on accidents incidents, inspections, audits and accreditation in improving safety and environment performance. This data together with data from Coal Mines Insurance and WorkCover NSW is being used to provide trend and comparison information. The NSW Injury Risk Management Research Centre at the University of NSW has been engaged by the Department to collate and prepare a detailed analysis of the data. Through this process, five areas have been identified for further research. These being: electrical energy, mechanical equipment, work environment, hours of work, and contractors involvement accident and incidents. The paper covers: the establishment of a mix of performance measures for the industry to indicate whether the safety performance is improving; the provision of data to provide useful comparisons and benchmarks against which companies can compare performance; the development of positive performance measures; the findings and outcomes of the detailed analysis of electrical energy; shocks; the provision of information to industry; an outline how the data is being used to determine departmental; operational priorities; and future plans to undertake research into the other areas identified.

Jan 1, 2003

While specific definitions of the main categories of mineral reserves and mineral resources are becoming well established through the efforts of the Australasian Joint Ore Reserves Committee (JORC) and the Combined Reserves International Reporting Standards Committee (CRIRSCO), there has been perhaps less attention paid to the standardisation of language used in the definition and reporting of Mineral Exploration Results and a clear understanding of the transition to Inferred Mineral Resources. This is an area of significant importance to small and medium sized enterprises in the mineral exploration sector as it represents in many cases the only tangible information by which the reader or potential investor can evaluate the future potential of such enterprises. By its very nature information in the Mineral Exploration Results category is incomplete, and frequently complex, and it is open to a broad range of interpretation by readers of various competency levels and disciplines. Many will have a short-term speculative view rather than a long-term perspective, with others out deliberately to misrepresent the information, and as such it can have an enormous impact on investment decisions if the risks associated with this information being reported are not fully understood. Authors of reports on Mineral Exploration Results, who may be Competent Persons or company directors, have to put themselves in the shoes of the reader of the report, second-guessing if you like what the reader will understand by a report, which in many cases will be of a highly technical nature. This raises reporting dilemmas and questions that require to be understood and addressed. Looking at reports on Mineral Exploration Results from the other side, readers have a degree of responsibility as well, particularly if they engage in an advisory or communications role. The tendency of commentators, journalists, analysts, and bulletin board posters to over-exaggerate the significance of a particular exploration result is all too familiar. Questions arise here as well about whether there should be more regulatory supervision and control exercised over those who use this information, all of whom greatly influence investment decisions, and many of whom have no idea there is a Reporting Code, far less an understanding of it. Examples are given and questions raised to illustrate the dilemmas surrounding the reporting of Mineral Exploration Results. In order to retain credibility with markets it is incumbent on companies to be transparent, not to be selective and to report all material information. On the other hand, information has to be taken and read in its proper context in order to avoid fuelling dramatic and unjustified company share price escalation. Timing of course is another factor that can affect the market price of shares, which may be beyond the control of those making the reports. Emotive and imprecise language, however, when reporting Mineral Exploration Results, coupled by speculation, can trigger damaging short runs on shares and destroy credibility where formerly there was long-term promise. The paper will review how Mineral Exploration Results are dealt with in various jurisdictions, and conclude that there has to be a balance between prescription and the tempering of undue optimism on the one hand, and the entrepreneurial spirit, which the industry needs, on the other.

Jan 1, 2002

The world is getting flatter through internet, mobile phone technology, relatively low cost travel, massive outsourcing of manufacturing to China and the transfer of company backroom operations to India. In the iron and steel industry, however, things will remain relatively the same with slow gradual improvements in technology; only the geographic location of plants may change over time. Or will it? The blast furnace smelting process has remained largely unchanged since 1828 when James Neilson came up with the idea of preheated air being delivered to the tuyeres. Likewise, oxygen steelmaking that takes molten iron from such blast furnaces has remained conceptually unchanged since Sir Henry Bessemer invented an air-based system in 1856. These two processes are the core of integrated steel mills that we know today. Typically such mills consist of coke ovens, sinter plant, blast furnace, oxygen steelmaking, continuous caster, rolling mills and metal coating lines. In the intervening 150 years the only real disruptive technology to the integrated steel mill has been the minimill. Based on the use of the electric arc furnace (EAF), in conjunction with a continuous caster and rolling mill, the term minimill is used because steel products are produced at down to one-tenth the scale required for economic operation of an integrated mill, with the EAF producing molten steel using largely scrap steel as its feed, as against transforming coal to coke (coke ovens), iron ore, coke and limestone into molten iron (blast furnace) and molten iron to steel (oxygen steelmaking). There are, however, a number of technologies in development that may cause a paradigm shift in the way steel products are produced and perhaps push the evolution of the minimill as a disruptive technology. Two examples are direct iron smelting, where iron is produced in a matter of seconds by injection of ironmaking feed materials into a molten bath, and thin strip casting, where molten steel is cast into 2 mm strip or less, in similar time. Both have Australian connections. A leading iron smelting technology is the HIsmelt« process, which has its first commercial application at Kwinana, Western Australia, where a joint venture of international parties, consisting of Rio Tinto and the Nucor, Mitsubishi and Shougang corporations, are in the stage of ramping up commercial production. The leading strip casting technology is the Castrip« process that arose from development work done by then BHP Steel, with IHI of Japan, at Port Kembla, New South Wales in the 1990s. Nucor followed this work up, building the first commercial plant for the technology at its Crawfordsville site in Indiana in 2001 and has recently announced an intention to build a second plant in the USA. While both technologies are only into the early stages of commercialisation they are likely to change the face of iron and steelmaking as we know it over the next 20 years. This paper elaborates on the technology of the two processes, why they could change the face of the iron and steel industry forever, what might drive the rapid change and what the changes may look like.

Jan 1, 2006

The United StatesÆ reporting standard for the mining industry for securities purposes is contained in the Security and Exchange CommissionÆs Industry Guide 7. It defines proven and probable Reserves using its own definitions, and prohibits the disclosure of quantitative estimates, for all mineralisation other than those two Reserve categories (though disclosure of Measured and Indicated Resources as quantitative mineralised material estimates is now informally allowed). Similarly, it restricts disclosure of value estimates to Reserves only, which SEC policy generally requires to be on an historic cost accounting basis. The SEC does not maintain a formal Competent or Qualified Person policy. In March 1999, the US-based Society of Mining, Metallurgy and Exploration (SME) released an update of its 1991 guidelines for definitions to be used in reporting of Mineral Resources, Reserves and Exploration Information, closely abiding by the 1997 CMMI recommendations. However, without SEC recognition, reporting under the SME and CMMI definitions is effectively barred for US companies. The SEC intends to adopt the International Financial Reporting Standards (IFRS) of the International Accounting Standards Board (IASB). This will occur within just a few years, when the convergence project for development of the IFRS has reached a satisfactory point. The US is the largest financial supporter and participator in IASB. The Extractive Industries Standard of the IFRS will likely terminate Industry Guide 7. However, the effect of this international replacement will likely be equally restrictive. This could possibly neutralise the benefit of a CMMI-based global reporting standard. SME, the US society encompassing the widest range of mining industry professionals, does not have a Code of Ethics. It has no mechanism for requiring members to abide by a professional standard. SME is presently looking into possible solutions for this deficiency. US-based professional societies that do have a binding Code of Ethics, generally cater to a single profession, and are not just mining industry related. The American Institute of Professional Geologists (AIPG) and the American Institute of Minerals Appraisers (AIMA) are examples. The SME is considering creating a subsidiary body with an enforceable Code of Ethics. To support a CMMI-based global reporting standard, competent persons will need to work across international borders. A standardised mechanism for qualifying and registering competent persons will be needed. National rules and laws must allow competent persons to easily enter countries to perform their work. State issued licenses are increasingly required for much of the work performed in the US mining industry by engineers, geologists and minerals appraisers (valuers). Such licenses are not required by the SEC for Reserve reporting in the US, may not be required for valuation of mineral properties under certain circumstances, and except for real property valuer licenses, they generally do not have a binding code of conduct. However, state licensing of professionals forms a substantial and increasing barrier to interstate trade in professional services, and can be a prohibitive barrier to professionals from outside the US. Any rationalisation of this confusing patchwork of regulations confronting US minerals industry practitioners will only occur as part of larger, national change, hopefully aimed at compliance with international standards and protocols. The US does not have a valuation standard aimed specifically at the mining industry. The Uniform Standards of Professional Appraisal Practice, the national valuation standards, often must be applied to mineral property valuation, but contains no specific instructions for minerals. The author has campaigned against development of minerals valuation standards proposed by US minerals institutes. Instead he encourages the mining industry worldwide to place its support behind the initiative of the International Valuation Standards Committee (IVSC) to include an extractive industries section in its International Valuation Standards (IVS). This should provide a global set of valuation standards for the mining and petroleum industry within two years. This addition to IVS will provide essential valuation standards reference support for the extractive industries financial reporting standard of the International Accounting Standards Board. The IVS has achieved a high level of acceptance in the developed and lesser developed countries of the world. It provides a comprehensive framework of Generally Accepted Valuation Principles for the valuation profession internationally, for valuation of all property or asset types. IVSC is effectively a sister organisation to IASB. The IASBÆs International Financial Reporting Standards (IFRS), previously known as the International Accounting Standards (IAS), reference and quote IVS in some instructions for determination of fair value. IVSC is a non-governmental organisation (NGO) member of the United Nations and maintains liaison with many important international economic, accounting and financial agencies, such as the OECD, IMF and WTO.

Jan 1, 2002

The Vertical Crater Retreat (VCR) mining method was used to mine two rib pillars at New Broken Hill Consolidated Limited (NEHC) mine at Broken Hill. Experience gained in a trial VCR pillar stope was applied to the design of Panel 3CN pillar (P3CN). Restricted access and a central sandfilled plug in this pillar necessitated the use of angled blastholes and blasting of the stope in two sections. Borehole surveys and close charging supervision were necessary to block, charge and stem the spherical charges in the correct position. The laver sections of the VCR stope with rock walls attained an average slice advance of 2.2 m whereas the higher section of the st.ope between cemented fill walls attained an average slice advance of 3.4 m. Achieved fragmentation was extremely fine. External dilution was assessed at less than 10 per cent. A cement consolidated sandfill exposure of approximately 1300 m2 stood vertically with no significant slumping.

Jan 1, 1983

Australia had an active uranium mining industry in the 1950s with uranium oxide being supplied under contract to the atomic energy authorities of the U.K. and U.S.A. In the 1960s, when these con- tracts concluded, domestic production ceased, apart from Rum Jungle, whose production until 1971 was stockpiled. By the 1970s, the demand for uranium from the electrical utility industry had risen sharply and the effects on Australia were notable. The Mary Kath- leen mine re-opened in 1976 but, more significantly, exploration activity suddenly expanded with the re- sult that several world-standard deposits were locat- ed. Western world requirements for uranium based on increasing energy consumption and a changing energy mix, will warrant the development of Aust- ralia's resources. By 1985 our mines could be pro- ducing 9,500 tonnes of uranium oxide yearly and by 1995 the export value from uranium could reach that from wool. In terms of benefit to the community the economic rewards are considerable but, in terms of providing energy to the world, Australia's uranium is vital.

Jan 1, 1978

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 M Kilburn, A Edenton, M Adam, A Dehghan-Manshadi, R Smyth, L Lu

The blast furnace is a counter current reactor. The counter current principle of the furnace makes it very efficient in transferring the heat and mass required to drive the reduction reactions inside the furnace. However, this does impose a stringent requirement on the permeability of burden material in the furnace. Lump ore is one of the key ferrous feeds used in the blast furnace ironmaking process, often accounting for ten to 20 per cent of the blast furnace ferrous burden. As the lump ore descends through the blast furnace, it is dried, heated and reduced by the ascending hot reducing gas. To ensure good furnace permeability, generation of fines from burden materials including lump ore due to mechanical, thermal and chemical processes needs to be minimised. Unlike sinter and pellets, lump ore is subject to thermal degradation. To assess this behaviour of lump, the ISO decrepitation test (ISO 8371, 2007) is often conducted, and the result is calculated as a decrepitation index (DI). However, the DI values obtained from the existing ISO decrepitation test vary considerably between test portions and between laboratories, which makes meaningful comparison very difficult. In order to identify the sources responsible for the unacceptable repeatability, the effect of various testing conditions, such as particle size, heating rate, sample preparation and loading method, on the mean DI value was studied. The mechanisms contributing to thermal degradation in the top of the blast furnace and during the standardised decrepitation test are also discussed.CITATION:Lu, L, Kilburn, M, Dehghan-Manshadi, A, Adam, M, Edenton, A and Smyth, R, 2013. Thermal degradation of lump ore in the top shaft of blast furnaces, in Proceedings Iron Ore 2013 , pp 421-426 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By D J. Clark, S Hewson, T Li

Cadia Hill Pit is a gold copper porphyry deposit hosted in monzonite. The pit slope design is primarily based on structural controls related to faults and shears with largely massive rock masses between the structures. The slope design attempts to achieve an optimum configuration at a bench to overall scale, considering economics and safety implications against the geotechnical and structural conditions. To date the slopes have been mined at interramp angles of up to 60¦ over heights of 120 m. Limited slope and batter failures that have occurred are structurally controlled and occur rapidly. The pit-mining schedule requires concurrent mining of part of the final pit walls and the progressive interim cutbacks. Engineering and operational solutions to hazard reduction and risk management issues have been implemented wherever viable to æengineerÆ out the hazard and mitigate the risks. However, comprehensive management plans and operating procedures have also played a vital role. This paper details the management plan and the operating procedures that have been developed and implemented to mitigate the risks associated with rock falls.

Jan 1, 2003

Gravity concentration of tin at Renison Limited uses tables and spirals to treat the various coarser fractions produced from sulphide flotation tailing. An acceptable final tailing cannot be made from one pass over the tables and spirals and therefore the tailing from these separators is reground and combined with the sulphide flotation tailing as the feed to the classification section. The gravity section became increasingly overloaded in the years preceding 1976 due to efforts to maximize tin recovery to the gravity concentrate. In April, 1976, two 2DSV Reichert cone concentrators in series were installed to treat the table and spiral tail- ing stream, prior to regrind, to scavenge a small tonnage of hard, coarse low tin grade material for rejection to final tailing. Gravity section loadings were decreased markedly, allowing operator attention to be directed more to table performance than to spillage collection. An increase in mill throughput of approximately 15% was possible following the commissioning of the Reichert cones. The cones are currently operated to make the minimum tonnage of tailing consistent with reasonable- gravity section loadings.

Jan 1, 1978

By C van Wyk, I Reeves, J Webber, G B. Gnoinski

The minerals industry has been given an opportunity to grow and continue to advance again in an environment where there is the potential to reap big rewards for efficiency improvements due to buoyant metal prices and the growing demand of markets in Asia. Improving efficiency may also provide a better return compared to risks of expansions and bringing new projects online due to limited human and financial capital.An opportunity for improvement presents itself in the area of mine-mill reconciliation, which entails the quantification of the variance between measurement points along the mining value chain. Reconciliation factors are calculated from the variance between respective sections within the mining sequence. These factors are commonly used as key performance indicators to provide a check on the performance of the operations. Over parts of the mining value chain, there is a fair understanding of the reconciliation between the Resource and Reserve estimates and the measured metallurgical plant inputs and product outputs through understanding of the mine-mill interface. The quality of reconciliation data gathered across the mine and plant is generally not well established due to practices employed in generating the data. The reconciliation variances are often a function of data accuracy and quality used in the comparison. In general, the sources and magnitude of measurement and sampling errors and their impact on reconciliation are not that well understood. Examples of the current practices of mass measurement, sampling, sample preparation, chemical analysis and quality assurance for broken ore and across the metallurgical process stream are considered. Guidelines are given for those reconciliation elements that are identified as requiring a high degree of confidence for Mineral Resource/Reserve and metal accounting reporting. These guidelines are presented and practices are demonstrated to improve mine to mill reconciliation and support increased resource to product efficiency and value.CITATION:Gnoinski, G B, van Wyk, C, Webber, J and Reeves, I, 2012. Guidelines and practical applications for continuous improvement in mine to mill reconciliation, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 309-316 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By Canterford J. H, Bologiannis F, Smith A. N

The Mutooroo copper mine is one of a number of deposits that have been evaluated by Adelaide and Wallaroo Fertilizers Ltd as a source of feed for the production of high- purity copper oxide at their Burra plant. For this deposit, the technique of solution mining or in-situ leaching appeared ideal. The Mutooroo production circuit and the results of the process optimization and environmental monitoring programmes are outlined. At the end of the experimental period described here, the production liquor typically contained I g/litre copper, yield- ing in excess of 5 t/month of cement product containing about 80 per cent copper. The environmental monitoring programme provided clear evidence that there had been no un- acceptable alteration to the properties of the groundwater in the country rock surround- ing the mineralized zone. It is anticipated that the experience gained at Mutooroo will be of considerable help in the development of other solution mining operations.

Jan 1, 1983