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By S Marsters

Imerys Tableware New Zealand Limited has mining rights to four deposits of halloysite, which are located about 203 km north of Auckland, New Zealand. These primary deposits were formed by the hydrothermal alteration and weathering of rhyolite domes. Halloysite clay is currently being mined from two of these deposits and then processed for export markets. From humble beginnings in the mid 1950s, the Northland halloysite was processed initially for paper filler markets and then for higher value tableware and technical ceramic niche export markets. The paper will briefly cover the geology and processing of halloysite and then examine the history of New Zealand China Clays Limited, now Imerys Tableware New Zealand Limited and then look to its future as part of global industrial minerals company, Imerys.

Jan 1, 2002

By Jensen B

The approach of using the Coward Triangle for the analysis of flammable mine gas mixtures has been examined for its application, to the flammability of coal dust/gas/air mixtures. Explosible lean limit and rich limit concentration data for dust/methane/air mixtures are examined and illustrated using co-ordinate geometry. It is concluded that a three-dimensional envelope representing hybrid explosible mixtures can be drawn. The dimensions of this explosive zone will vary with the characteristics of the coal dust and the gaseous composition of the mine atmosphere. Further research is needed to establish these dimensions for important mined seams.

Jan 1, 1994

Existing fluid flow techniques may be readily applied to the design of ranges for seam gas drainage. The Reynolds number characterises the flow regime within the pipe and it can be used in conjunction with data on absolute pipe surface roughness to determine the system friction factor. The application of the solution to the isothermal compressible flow equation utili- sing Moody friction factors and the concept of equivalent length of pipe for fittings and valves provides a practical method for sizing gas ranges. The physical capacity of a range can be decreased by the existence of significant quantities of water in the range and also by the ingress of air into the system at poor pipe joints etc. Both problems can be elimin- ated by adequate attention to design detail.

Jan 1, 1982

By Schommarz KH, Dunne RC, Goodall CM

Column cells are widely used today for the recovery of base metals by flotation. Their use for the flotation of iron sulphides has not been as rapid. Australia has pioneered the use of large rougher flotation columns. During the last six years, seven rougher columns have been installed on gold mines treating iron sulphides and the technical viability of this technology has been demonstrated. Laboratory column testwork on a gold bearing iron sulphide ore demonstrated the effects of both physical and chemical parameters. In general the large commercial columns operate over a broad range of conditions depending on the downstream treatment of the flotation concentrate. The addition of wash water to commercial columns is not universally applied and there appears to be a need for a better wash water System.

Jan 1, 1993

By Weyer J

Many existing computer planning programs for the mining industry focus either on big mining enterprises with a high production rate or on smaller operations for high value minerals. Big mining enterprises, like the hardcoal company `Ruhrkohle AG' in Germany have their own R&D departments which develop powerful computer programs for planning purposes, partly in co-operation with mining universities. However, there is a remarkable number of small- scale mining operations which are either not able to buy expensive hard- and software or don't have the skills for the operation of extensive software programs. Partly there is also a trend in using rule of thumb calculations rather than computer programs which need a lot of - partly unavailable - data. For this reason a computer program was developed which does not need expensive hardware and software and which can help the planning engineer in the selection of a limited number of possibilities. Until this time the planning engineer established two or three different cases and calculated the results with a pocket calculator. This could last some hours or even some days. Now he or she can use the computer program with a normal PC to compare the cases. All activities are menu-driven. The basis for all, calculations are fixed and variable costs as well as average performance for special activities. The paper gives an example for a possible planning situation in fluorspar mining (originally this program was developed for the fluorspar enterprise Lengenfeld in Germany). It shows the initial situation, the main structure of the program, the input logic and the results. Benefits, limits and possible extensions of the program are discussed.

Jan 1, 1995

By J Watson

Electronic detonator technology has been under development for the last two decades. Currently, there are a number of systems commercially available with several others still under development, each with its own unique features. This technology can offer a significant advantage to the drill and blast engineer through their ability to initiate an explosive charge at the æplannedÆ time. This new technology has created huge interest within the drill and blast community and also raised their expectations to produce better blasting outcomes. In many cases, specifications (or even expectations) of desired blast results are not properly defined. Interaction between the input variables (rock mass characteristics and blast design) and results (fragmentation, throw, damage, ground vibrations, etc) and their mechanisms, or relationship to one another, are not very well defined or understood. That is why rock blasting is still considered by many as an art rather than science. With one of the few remaining variables (cap scatter) now controllable, todayÆs blaster finally has the ability to apply science to his trade. Even though electronic detonators are available and becoming more commonly used, current field practices are not always conducive to extracting or deriving the maximum benefit from this new technology. In the authorÆs opinion, the following need to be understood to derive and sustain the maximum value: clear definition or specification(s) of desired outcomes from a given blast; impact of different features in an electronic detonator system (precision, accuracy, flexibility, reliability, etc) and their impact on the desired blasting outcomes; interaction of blast design variables (energy, energy distribution, timing, blast geometry) and their impact on desired outcomes; impact of rock mass variability and quality of blast implementation on the desired blasting outcomes; and critical need to utlilise appropriate tools and systems in order to measure and quantify benefits.In the authorÆs opinion a scientific implementation process is the key to derive the benefits. This paper analyses the industryÆs preparedness to derive the benefits from this technology and proposes a scientific methodology to understand, evaluate and sustain the value from this technology.

Jan 1, 2004

By Porter I

Rock mass classification systems have emerged as a powerful tool which can be used for assessing ground conditions and determining support requirements in underground mines. They should not be used as a substitute for complete engineering design, but rather as a supplement to observational methods and analytical study. In general, the use of rock mass classification is attractive, but each classification system has various deficiencies. Use of any particular system should be made only with knowledge of that systems limitations. It is desirable to employ a number of systems and design methods which will allow for comparison and lead to a better understanding of the rock mass condition.The Rock Mass Quality system (Q-System), developed by the Norwegian Geotechnical Institute, and the Rock Mass Rating (RMR) System, Bieniawski, were designed primarily for civil engineering structures. Laubscher et al (1978) further developed the RMR-system specifically for rock mechanics engineering in the mining industry. A method of stope design, which introduces a stability factor for the rock mass and compares this with hydraulic radius, was developed by Mathews et al (1981). This paper reviews the above systems by applying them to stability assessment of crown pillars in two Australian metal mines and provides a critical analysis of the various approaches. In particular each system will be analysed to determine its suitability for use in crown pillar design. The most suitable system(s) will form the basis for future development in crown pillar stability analysis.

Jan 1, 1994

Effect of Hardwater on Selective Flocculation of Diasporic-Bauxite

Sep 13, 2010

As this paper is being written primarily for perusal by milling workers, metallurgists and engineers, an attempt will be made to avoid the use of accounting technicalities. Its scope will be confined to a description of the methods employed in the collection of basic information for use in timekeeping, costing, and the compilation of statistics.TIMEKEEPINGEvery applicant for work is asked to furnish the following information, which is collected on a card (size 6 in. x 4 in.)...

Jan 1, 1922

By Di Pasquale S, Osler GD

Mount Isa Mines Limited recently commiss ioned an 800 tph Heavy Medium Preconcentration Plant for lead/zinc/silver ores. The decision to build this plant was made in late 1979 based largely on investigations conducted in the Company's pilot plant on a variety of ore types including Hilton ores, between 1972 and 1978. The paper reviews the historical develop- ment of the pilot plant heavy medium circuit through this period and illustrates the extent to which this work impacted on the final design criteria. This review also includes a description of plant operation, manning levels, process equipment and metallurgical performance Achieved.

Jan 1, 1978

Petroleum exploration is proceed ing in Western Australia at an ever- increasing pace. Results in recent years have been very successful, with the discovery and development of the Barrow Island oilfield and the Dongara gasfield, and the discovery of several major gas-condensate fields on the Northwest Shelf. The Northwest Shelf discoveries will have a big impact on the economy of the State by providing an abundant indigenous source of energy. Prospects for further large dis- coveries are believed to be excellent. The most prospective areas are thought to be on the continental shelf in the Carnarvon, Browse, Perth, Canning, and Bonaparte Gulf Basins.

Jan 1, 1973

By C Pypno, P Nowakowski, T Opasiak, C

Belt conveyors are machines for continuous transport with most applications in mining industry in Poland. This is a result of simple construction and cheap operating costs. But conveying materials by belt conveyors are often in the powder state (eg small coal, gypsum, etc) and during the transport there is a possibility of polluting the environment around conveyor route. A good solution for this problem is the pipe conveyor, where a belt is closed on the route in circular shape and flat on unloading point. Another problem which is indicated in the paper is dusting on the belt conveyor boosters. In Poland a new solution of booster has been designed, whereby dustiness of transportation powder materials is reduced by up to about 90 per cent.

Jan 1, 2003

The recommendations of a recent American report on "Better contracting for Underground Construction" are considered in relation to Contracting practices on major Australian projects by representatives Of the "classical trilogy" - the Owner, Engineer and Contractor.

Jan 1, 1976

Existing production facilities are constantly looking at ways to increase capacity. Many recent solutions have focused on the implementation of capital and infrastructure projects. It is accepted that capital expansions are frequently necessary for production gains; however, in many cases existing assets have the potential to deliver substantially better throughput than they are currently achieving. By focusing on automation of production control systems, production reporting and business processes substantial gains can be achieved utilising existing assets. This potential can be realised quickly and has been proven across several sites and industries. In the Pilbara region of Western Australia throughput gains of between two per cent and 25 per cent (translating to millions of tonnes per annum) have been achieved from existing assets using the methodologies discussed. The improvement process involves evaluating the entire production chain from the time the ore arrives at the plant to the time it is dispatched. A technical evaluation of the performance of the control system and plant automation interfaces to upstream and downstream processes is conducted. The relationship of these processes to the business systems and the human interface to the systems is reviewed to ensure a complete picture of the system is understood. Technical evaluation targets include: individual equipment operation, the engineering level of control systems, feed controls, etc; managing recirculating loads, surge capacities, dynamic inventories as well as management of in-feed systems and integration into yard and out-feed systems; and communication flow between control and other systems, data alignment between rail and shipping schedules, yard systems, sales systems and maintenance systems including such fundamentals as truck dispatch links to plant control. In parallel with the technical evaluation, business system evaluation takes place, including analysis of the operational systems, methods and personnel.

Jan 1, 2007

In the face of intense global competition and other business pressures on coal miners, ongoing quality initiatives and continuous process improvements are needed to enhance business performance. By viewing a minesite in terms of key processes, rather then departments, and employing innovative technologies and better applying organisational resources, there exists enormous potential to achieve reductions in process cost and time.

Jan 1, 1998

The BHP Steel Group embarked on a Total Quality Control (TQC) programme in 1984 in response to enquiries from a major customer regarding procedures for quality in materials supply.The TQC initiative has been adopted by all seven Divisions of the Steel Group and covers a broad and comprehensive range of management and workforce improvement initiatives.The development of the TQC initiative in the Collieries Division of BHP Steel over the past eighteen months has resulted in important experiences and leanings.

Jan 1, 1991

By R Puglisi, G McPhail, B D. Jilbert

The increased international focus on sustainable development and cost improvement, coupled with the unpredictability and adverse impact of droughts in Australia and globally, has highlighted the critical need for responsible management of water within the minerals industry. The Rio Tinto Technology Group recently initiated a priority program to examine how water management practices could be improved within the GroupÆs spheres of activity. Rio Tinto Technical Services (TS), the technical services consulting group of the Technology Group, has for many years been undertaking water management reviews and assisting group operations with the development of responsible water management strategies and plans. Rio Tinto therefore requested that Rio Tinto Technical Services develop a world-class approach to mine water management that will drive improvement in strategic assurance and operational efficiency of water at the companyÆs managed operations across the world. The initiative, known as æExcellence in Water ManagementÆ, includes the selection and use of state-of-the-art management, technical tools and methodologies to strive for best practice. The Rio Tinto Technical Services approach facilitates a consistent and objective assessment of performance across the entire spectrum of complex water management issues within a mining operation, from initial exploration through to decommissioning and close-out of the operation. Based on this rigorous assessment, detailed action plans can be developed, prioritised and scheduled for subsequent implementation. This paper presents the progress and experience gained to date in the æExcellence in Water ManagementÆ program, demonstrated by means of a pilot study conducted at Northparkes Mines in New South Wales.

Jan 1, 2003

By M Vavro, V Slivka, J èterba

In the course of the last ten years the development of the mining industry in the Czech Republic has been influenced by the pushing through of economic and ecological criteria. Due to this coal mining was ended in the whole series of the underground coal mines. These mines become the source of ecological and safety risks û methane leakage, surface deformation, etc. The way of solving of these problems is by stowing of underground spaces, and also surface fault basins with the help of mixtures produced from industrial wastes. The presupposition of this procedure is knowledge of prescriptions for production of the mixtures, and of the economic advantageousness of carrying out these activities. This contribution pays attention to the utilisation of power-gypsum as a raw material in the production of mining-construction materials.

Jan 1, 2003

The Income Tax Assessment Act ["the Act"] levies tax on a taxpayer's taxable income. At a time when commerce and life were more simple, the calculation of taxable income had some connection with logic and a taxpayer's capacity to pay. However, as a result of successive governments' different views of equity, their perception of avoidance, their needs for revenue and their changing views on capacity to pay, the rules determining the calculation of taxable income have continually changed to the point that logic is no longer relevant. Taxable income now is simply the product of the application of a complex set of rules.

Jan 1, 1990

By A B. Bell

The health and in some cases survival of mineral exploration and mining companies is, in today's markets, more dependant than ever on the effective use of information technology. The need for speedy collection, organisation, maintenance and distribution of corporate and project information is a phenomenon that will continue to strengthen with market thirst.Geographic Information Systems (GIS) provide a medium for storage, maintenance and retrieval of data, and Internet Mapping adds a technology for effective distribution of that data. Combining these technologies can return benefits both fiscally and technically by reducing costs of ownership in IT infrastructure and increasing the efficiency and effectiveness of both internal and external information delivery.GIS and Internet Mapping technologies have reached a practical stanza in their evolution and will continue to develop as a key business tool in the natural resources sector.

Jan 1, 2002