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A number of suggestions have been made to improve the design of cells used for electro winning and electro refining of metals. Most of these designs have been aimed at increasing the current density used in order to improve cell capacity, although the purpose of some has been to produce electro deposited metals in a continuous manner. Improvements in the electrolyte flow pattern in conventional cells have resulted in an increase in the rate of mass transport of metal ions to the electrode surface; giving rise to lower concentrat- ion polarization and an improvement in the nature of the product obtained, Other cell designs are based on a moving electrode, usually a rotating disk, and these may include provision for removal of the product in a continuous manner, The maximum current density which can be used in an electro- lytic deposition process is determined by the limiting diffusion current, the physical nature of the, product, the purity of the product required and by the increase in power costs which result from the higher cell voltages, This paper examines the properties of an agitated bed of particles as an electrode system when used for a metal deposition Process,

Jan 1, 1969

By G Johnson, S Michalek, N Redman

As the modification of the 2009 Mill OperatorsÆ Conference theme from æmilling through the boomÆ to æthe boom û experience gained and lessons learnedÆ exemplifies, comminution practitioners are facing a series of challenges in the dramatically changing mining environment. One of the main problems plant managers have been facing during the boom times has been the severe metallurgy skills shortage and high staff turnover, both factors that can cause difficulties in mill liner management. Many of todayÆs mill managers are now also more than ever faced with the need for cost-cutting in order to continue operating viably. Amongst other potential target outcomes such as maximised throughput, MillMapperÖ, a tool for mill condition monitoring and mill performance optimisation, can be utilised to address these issues. This paper demonstrates how MillMapperÆs quantifying decision making tools can serve to be in control of managing mill liner and production issues, and how it can form the basis for mill cost savings without the risks normally associated with conventional methods or the lack of using any condition monitoring methods. MillMapperÖ is currently being referred to at a rate of approximately 150 surveys and associated reports per annum at processing plants in Australasia, South America and Africa. Examples throughout the paper provide insight into how the presented sample set of users have extracted benefits that could have otherwise not been safely or at all achieved.

Jan 1, 2009

The paper describes the reasons for the development and for the selection of systems which were finally adopted; further estima- tion and design engineering problems, as well as experience with large screens in operation. Advantages, disadvantages and the final li- mits of screen dimensions are indicated.

Jan 1, 1984

The accurate determination of trace level gold in ores, metallurgical samples and process solutions is required because of the value of gold, the efficiency of the cyanide leach process and because of the high gold recovery from these cyanide solutions. It is thus necessary to routinely analyse geological and metallurgical samples with gold concentrations of 3 g tonne (ug g- 1ppm) and process solutions with a gold concentration of 0.01 mgL 1 (ppm) preferably with sufficient accuracy to quote at least two significant figures. Several techniques have been reviewed for their suitability for the routine gold analysis of these samples which also contain signif- icant concentrations of other ions. The classic fire assay technique has achieved the respect and confidence of mining personnel because of the results achieved by very experienced assayers. Other extraction and concentration techniques have now been shown to be equally effective. The use of instrumental analytical techniques particularly atomic absorption spectrometry have shown that cheaper procedures, which are as reliable, are now available to gold producers for the routine analysis required to maintain an efficient gold recovery process.

Jan 1, 1982

Leadership challenges for mine management over the next decade will be primarily about doing more with less labour. This will require a greater focus on people leadership and management, reducing uncertainty by evening out employment peaks and troughs, understanding and addressing our demographic destiny and its implications whilst identifying and holding onto our mission critical employees, managing creativity and accepting diversity whilst providing flexibility in employment for work-life balance. Greater emphasis will also be required on the non-technical social skills of complex interactions with community and education providers and finally a greater emphasis on forecasting and planning for the provision of future skills needs. Skills needs will become an ever increasing priority in risk management as retention starts with attraction and remember: SATISFACTION = REALITY                                EXPECTATIONS These are the challenges and opportunities for leadership and mine management of the 21st century to assist in better meeting and maintaining our human resources needs and thus contributing to the sustainability of the sector in Australasia.

Jan 1, 2006

By Jingmin Xin, Wenhua Xing, Zongxin Huo, Hongzhang Chen

Drawing up the successive plan for mining and development is a very important and regular plan work. The expert system of the successive plan for mining and development drawn up by computer is developed on the basis of network, computer simula

Jan 1, 1998

By Shihui L, Lianfu Z, Llanming J

The paper considers the essence of the multi-objective decision-making issues for selecting an optimal mining plan, and analyses the advantages and disadvantages of the multi-objective decision-making techniques commonly used for selecting an optimal mining plan. It presents the principle and practice of using a group-AHD with mixed factors to select an optimal plan.

Jan 1, 1995

By M Heidari, M Ataei

Today, the selection of a mining method is a multi-criteria decisionmaking process, with many factors in this process connected to each other. These trends do not have a high degree of confidence. In this study the analytical hierarchy process was used to select the suitable mining method for anomaly No 3 of Gol-Gohar iron mine of Iran. The results of this study show that gathering all existing information from the exploration stages and using AHP technique, the open pit mining method is the mining method for this anomaly.

Jan 1, 2003

By P O. Andersson

Mining of sill pillars is more difficult than the ordinary mining. The sill pillar mining is performed under more difficult conditions and the mining of the sill pillar itself produces more problems; failure of the rock due to high stresses, difficulties in controlling the fill above, overall stability of the stope and special requirements on the technique for backfilling. Altogether this makes sill pillar mining technically difficult and often not profitable. A project was therefore initiated with the aim to increase the mineable ore reserve by making sill pillars mineable, both technically and economically. The project aimed at developing technique for already existing sill pillars as well as planned sill pillars. For the existing sill pillars a technique would have to be developed for mining beneath unstabilised fill. For sill pillars that would be created in the future, the most suitable mining method and methods of supporting or stabilising the fill in the stope above was to be chosen within the project.

Jan 1, 1998

By M J. Saynor, W D. Erskine an, D R. Moliere

The Jabiluka uranium mine was constructed in the Ngarradj catchment, a right bank tributary of Magela Creek in the Northern Territory. The Jabiluka Mineral Lease is adjacent to Kakadu National Park, near an area listed as Wetlands of International Importance under the Ramsar Convention and recognised under the World Heritage Convention. In the late dry season of 1998 and prior to the 1998 - 1999 wet season, a stream-monitoring program was implemented in the Ngarradj catchment to collect baseline data on sediment transport within the catchment to assess and proactively manage associated impacts caused by mining at Jabiluka. Stream suspended mud concentration, stream discharge and rainfall data were collected for four wet seasons (1998 - 2002) giving an almost continuous data set. The stream system has high natural variability dependent on rainfall intensity and subsequent discharge and pre-wet season fire distribution and intensity. In general, mud concentration is elevated at the commencement of the wet season until about February. This is caused by first-flush removal of surface material detached during the dry season by agents such as bioturbation (including anthropogenic activity), wind erosion and surface desiccation. Water quality trigger values downstream of the mine were derived using upstream percentiles and the before-after-control-impact, paired site design. Both analyses showed no observable impact from mine construction in 1998 or during the study period. However, the impacts of dry season fires could be clearly detected. The data set provides good baseline information for future assessment at Jabiluka and demonstrates the need to view measured parameter values on a catchment-wide basis with knowledge of rainfall, discharge and fire distribution.

Jan 1, 2004

By Johnson M, Wooltorton B

A programme of hydraulic fracture stress measurements conducted in surface drill holes along the alignment of the King River Power Tunnel has provided information of importance to the assessment of the extent of steel lining requirements for the tunnel. A significant horizontal stress field has been detected at a location remote from the power station site, with a corresponding absolute minimum stress magnitude approximating the overburden pressure based on depth of cover. Measurements made closer to the power station site (located toward the bottom of a valley) have revealed an apparently relatively destressed region with minimum stress magnitude less than overburden pressure. The implications of these results are discussed.

Jan 1, 1987

The Project Financing Industry is currently being expanded en- compassing greater competition due to the improved worldwide economy. This has meant that money is in greater supply than demand for both loan and equity investment and is available for larger and higher risk ventures. The consequence of this is that the Project Financing Industry should be better able to provide more innovative forms of financing to meet the needs of mining and petroleum companies, regardless of size. Large mining and petroleum companies in Papua New Guinea should therefore be looking for ways to raise equity funds for exploration in greenfield areas, diversifying their risks through acquisition, and seeking to reduce their costs of borrowings. The small to medium sized mining sector should be looking to raise equity for increased ex- ploration on tenements and, where possible, to raise borrowings to fund expansion and further development of their projects. In summary, it is a period during which companies should take ad- vantage of available funding to augment their strategic plans and increase their long term returns to shareholders.

Jan 1, 1997

During Gepp's lifetime, Australia was in the forefront of science and art in metallurgical practice. This did not come easily for although blessed with a unique mineral deposit at Broken Hill large in size and rich in values much courage and daring was needed in the development of processes whereby they could yield the best results.The resultant development of the flotation processes at Broken Hill is one of the most important inventions of the 20th century.

Jan 1, 1993

Three methods of gold analysis are briefly described highlighting some of the problems and advantages of each. The variation of results between samples and splits and due to method preparation are illustrated. The mean percent difference of the fire assay values from the means of sample split values for three cases is 15%. Finally, a comparison of the aqua regia atomic absorption spectroscopy and fire assay fusion AAS techniques is made. This shows that the mean precision, the ability to obtain the same value, of the methods at 98% confidence are +30% and +15% respectively. The fire assay fusion atomic absorption spectroscopy method is relatively more accurate than the aqua regia method.

Jan 1, 1982

Routine, in-pit geological mapping of highwall at Central Queensland Coal Associates (C.O.C.A.) deep strip mines has proved too slow for the increasingly greater highwall lengths which require mapping. This realiz- ation has encouraged the search for faster mapping methods and after trial of ground photographic methods has resulted in the adoption of interpretive mapping off stereo cover, oblique -- aerial photography. This entails using a Cessna 182 light aircraft flying at its slowest speed, the aerial meth- od finally employed consisting of two Vinten, air reconnaissance cameras mounted in parallel and simultaneously taking both colour and black and white photographs of the mine high- wall. The respective 1:500 scale enlargements produced from the 70mm format films combine to present the sharpest resolution attainable under the field conditions pertaining and such information on weathered material as only colour photography can fully render. Total costs for the aerial photography method are estimated to be about the same as those for conventional in-pit mapping. Whilst total costs are comparable, geo- logist's time for mapping a 10 km. length is reduced to less than half that for in-pit mapping (for Stage 1, fully accurate mapping) and accuracy and detail are greatly improved. A permanent, accurate record of overburden

Jan 1, 1981

There are two main challenges in analysis of spectral data: to output as accurate an interpretation of the sample mineral assemblage as possible and to then use the spectral data to map out trends (downhole, across section or traverse) that will assist the exploration geologist to target drilling and further exploration. This paper will discuss methods of extracting the maximum amount of information from spectral data and examples of plotting the information downhole, in section and plan view to assist in exploration and mining. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By K McNabb, M H. Turner, P A. Jenkin

Mining of the Agnew nickel deposit commenced in 1970 using a variety of underground mining methods, though with mixed success due to the difficult ground conditions. WMC Resources Ltd acquired the operation in 1989, and commenced nickel production with an open pit. In 1995 all production reverted to the rejuvenated underground mine, using exclusively SLC (sublevel caving) methods. Currently the mine produces 1.4 Mt per annum, at an average grade of 1.74 per cent Ni. Underground mining of the Perseverance orebody has always presented significant challenges due to the difficult ground conditions in the weak and altered ultramafic rocks. The range of problems include areas of swelling minerals, intense and extremely weak shear zones, relatively high in situ stress, and in other areas very brittle rocks. Under these conditions rock mechanics input has been and remains a critical element of the mining strategy. Severe ground behaviour difficulties down to a depth of 500 m below surface prompted a review of the mining strategy for the large disseminated nickel orebody, including evaluation of alternative mining methods. However, sublevel caving was ultimately selected as the preferred method, and a re-design of the SLC cross-cut layout followed. A selection of rock mechanics investigations of interest are described, including complex virgin stress measurements, detailed ground behaviour monitoring, and the use of non-linear stress analyses to re-design the mine layout. Subsequent ground behaviour, support design and production scheduling are also described.

Jan 1, 2000

By P Waters, S Miller

BHPBilliton operates the Mt Whaleback Mine located in the semi-arid Pilbara Region of Western Australia. Approximately 200 Mt of net acid generating (NAG) material still remains to be mined. Acid Rock Drainage (ARD) was first identified at the site in 1995 following cyclonic storms. This resulted in the development of strategies that have allowed the mine to successfully manage ARD whilst continuing to operate. BHPBilliton Iron Ore is working toward prevention of ARD in its operations, however, historical practices have left residual areas that must be considered. Three significant sources of ARD have been identified that must be managed: stormwater run-off from exposed pyritic shales in pit surfaces; basal flows beneath overburden storage areas following rainfall events; and contaminated water from pit dewatering. The mine contains all ARD water onsite. This is achieved by: storage of all affected water in the ARD dam; evaporation of affected water from the ARD dam and the adjacent evaporation ponds; pumping from upstream dams to prevent stormwater from being affected; and emergency storage and treatment in-pit as a contingency. The site ARD management strategy is approved by senior management and endorsed by State Government regulatory authorities and relevant external stakeholders. Additional strategies are also under evaluation to effect long-term closure of the operation. Record rainfalls from 1998 - 2001 have tested the capabilities of the ARD strategy and management plan. Learnings from these events, coupled with recommendations from an extensive technical audit in 2000, have been incorporated into the strategy for ARD management. This paper presents the strategy and an overview of the ARD management plan that can be considered and applied by other affected sites in the management of ARD.

Jan 1, 2003

Access to land for exploration, development and mining purposes is extremely critical to the viability of the mining industry and subsequently the well being of society.The mining industry has been subject to environmental controls and considerations for the past 20 years. Today there is greater land use competition and more debate as to its use. To retain reasonable access the mining industry must comply with the rules and regulations by which it is governed.A new set of rules and regulations have been approved for use in Queensland, known as the Mineral Resources Act 1989. This Act clearly outlines the titles available and the requirements to obtain access.There are three main titles of interest to mining companies. These are an Exploration Permit, Mineral Development Licence and a Mining Lease.The Exploration Permit (EP) is for exploration purposes. Applications for EP's are assessed on their content and past performances. An EP is granted subject to a security deposit and conditions. Prior to entry the EP holder is required to inform the land owner of the proposed activities and times of entry.

Jan 1, 1990

By Zhang P, Wang T, Duan X, Sheng T, Kong L, Wang Y

This paper puts forward an artificial neural network (ANN) for the forecast of deformation of the surrounding rock deformation. On the basis of this, this paper gives some examples of its application. The results show that the ANN model has a high forecast accuracy.

Jan 1, 1995