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Mineral Sands - "An Industry for the Future"The mineral sands industry is matched only by the gold industry in relation to its current buoyancy. The strong demand for the various mineral sands products, creates a positive environment in which to review the technical and commercial factors affecting the future of this industry. This conference is clearly being held in the right place at the right time.My role today is to put forward a few ideas that may help Australia to assert its rightful role as a major downstream player in an industry which it has dominated for 25 years as a raw material supplier.

Jan 1, 1986

The originally estimated mine life at Kidston (starting 1984) was 12 years. Through a continuing process of re-evaluation and improvement in the operation and by expanding the geological knowledge in the region, the mine life has been considerably extended. With falling grades and harder ore, the additional reserves have come with increasing risk - not only in an economic sense associated with diminishing profit margins but also operationally, requiring innovative milling technology and geotechnical designs to provide a lower cost environment for continued profitable mine production.

Jan 1, 1994

Optimisation and sensitivity analysis of final pit limits is now an accepted procedure for open pit planning studies. Tools to assist the design engineer in an underground metalliferous mine to make optimal choices for the selection of major development, stope geometry and cut-off grade analysis have not been available. The engineer has had to rely on experience and a limited analysis of design alternatives. A new tool called the `floating stope' has been developed to define the optimal (boundary) limit for material that can be economically extracted by underground stoping methods. The method is analogous to the `floating cone' method of open pit optimisation. The geology and mineralisation are modelled as a regular or subcell block model. Included in the model are structural and geotechnical features, and any previously mined out areas. Inputs to the procedure include the minimum stope dimensions, cut-off grade, stope head grade, and the way in which dilution is to be calculated. The optimisation procedure can be directed to maximise ore tonnes, grade, contained metal or the economic (dollar) value of material mined. The procedure can be applied at each stage of mine evaluation and design to assist with preliminary resource appraisal, selection of stoping methods, and detailed mine design. As with open pit optimisation procedures, manual intervention by an experienced engineer is required to produce practical and detailed designs. This practical design should follow the optimised design as closely as possible. The paper outlines the algorithms used in the definition of the stope envelope, and describes the analysis and results of several case studies where the optimisation procedure has been applied.

Jan 1, 1995

Cataclysmic or flood-like release of gas-charged brines, hydrocarbons and slurries accompanied widespread mineralisation of Upper Devonian environments. These are well represented in the Canning and Burdekin Basins of Western Australia and Queensland respectively.The Burdekin Basin provides particularly instructive vein structural sequences. These fall into organic residue to carbonate paragenetic sequences which are known elsewhere to record progressive decarboxylation. Fibrous veins indicate overpressure in fractures with organic residues, acids and gas derivatives driven to overlying groundwater flows. This combination of large flow rates and potent organic mineralisers led to extensive arsenical rare-metal mineralisation which is similar to that concentrated in Upper Devonian extinction horizons of the Canning Basin. Organic-residue mineralisation appears concentrated by certain hvdrostructures and targeted upon particular species. These controls need to be understood to guide modern management stragegies for mineralised organic and nitrogenous wastes.

Jan 1, 1990

By Ishijima Y, Goto T

Displacement Discontinuity Method (DDM), which was originally developed by Crouch,S.L., is a powerful tool to calculate mechanical disturbances due to tabular excavations. Three topics on DDM applications to strata control problems in Japanese deep coal mines are described. First, is numerical simulation of microseismicity induced by longwall mining in Horonai Coal Mine. Microseismicity in the mine had been monitored by a mine-wide seismic ar- ray. Location of microseismic events and in- tensity of seismicity were well simulated. In the simulation procedure based on DDM, first, zones where a failure condition is satisfied by the advance of mining are detected. Then, the seismic moments, which indicate the inten- sity of seismicity, at the failure zones are evaluated. Second, is prediction of the shaft damage due to mining in Sumitomo Akabira Colliery. In this mine, the limit angle of the shaft pillar was changed from 600 to 800 to increase the amount of minable coal volume without increas- ing mining depth. Displacement of the shaft axis has been measured to assess the damage due to mining around the shaft pillar. In the calculation based on DDM, a fault intersecting the shaft and the ground surface are con- sidered. Observed and predicted displacement of the shaft axis agreed well.

Jan 1, 1992

By Davey P. T, Tsambourakis G

Mineralogical analysis of supergene sulphide ore recovered from areas close to the underground workings at the abandoned Mutooroo (South Australia) mine shows that the original sulphide minerals have undergone substantial alteration. The cause of this alteration is believed to be contact with the highly saline, acidic mine water. The copper is now present as a sulphide that can best be described as a copper- and iron-delicient chalcopyrite, CuxFeyS2, where in most cases x < y. The values of x and y vary from point-to-point within each grain.Leach tests under a variety of conditions show that dissolution of the copper from the supergene sulphide ore can be readily achieved, particularly when compared with the behaviour of Mt Isa chalcopyrite concentrate. For the supergene sulphide ore, an increase in the acidity and the iron(lll) concentration of the leachant re ults in an increase in the rate of copper dissolution.The results are briefly discussed in terms of the experimental in-situ leaching operation at Mutooroo, South Australia.

Jan 1, 1986

Rare-earth permanent magnetic roll separators, pioneered by our group a few years ago, have distinctly different operation characteristics compared to prior art electromagnetic separators of various types. Many new applications for dry high-intensity (or better: high-force) magnetic separation have been developed in a short time period. It has also been found that the new generation of separators generally are more efficient with regards to removal of weakly magnetic contaminants in glass and ceramic raw materials with minimum loss of valuable product compared to induced magnetic roll (IMR) separators.The latest development is in the area of production of clean magnetic concentrates at high recoveries. It is likely that the PERMROLLR magnetic separator will replace cross-belt and lift-type magnetic separators as a result of this most recent advance.The paper will review the features of the PERMROLLR magnetic separator in comparison with other types of magnetic separators on the market and give examples on applications.

Jan 1, 1990

By Thatcher R

In areas where land suitable for development is a scarce resource, an upgraded post-mining land use can result in economic benefits to both the mining company and to the community.A study undertaken at Aberdare Colliery near Ipswich during 198611987 assessed the costs and benefits of developing the site following mining for grazing, forestry and residential uses. The proposed fmal land use plan comprised a combination of these uses that can be upgraded to higher valued uses once subsidence monitoring of backfilled open-cut areas and dumps indicates that total settlement has reached acceptable levels for development to proceed.The study involved the documentation of existing site environmental parameters and the delineation of site opportunities and constraints. The unpredictable nature of settlement over backfilled open-cuts and overburden dumps represents the major constraint to urban development on mined areas.

Jan 1, 1990

South Africa is a semi arid, water scarce country that has undergone recent major political and social transformation. This transformation has ensured that water management has become a primary environmental concern in the South African mining industry, raising the status of water from an ancillary service to a fundamental factor in mine planning. The coal mining industry has been involved in the development of integrated catchment management plans since the late-1980s when a series of initiatives commenced in catchments where collieries operated. The plans focused attention on water supply and water demand management, the equitable access to water supplies, and intersectoral approaches to decision making, before the promulgation of new legislative and policy frameworks. Development of an integrated watershed management plan for the Olifants River basin, located in the Mpumalanga province, commenced in 1990. The Olifants River is an international river basin of 54 570 square kilometres and shared by South Africa and Mozambique. The upper watershed, locally called the Witbank Dam catchment, will be the focus of this paper. It has an area of 3400 square kilometres and is the major coal mining, power generating, and maize-growing region of the country. The processes embodied in the integrated watershed management plan had no formal guidelines but rather developed in an ongoing fashion over time. The plan commenced with a situation analysis involving the major stakeholders that identified principal technical shortfalls. These shortfalls were investigated under the guidance of multisectoral committees. The Olifants River Forum was started to extend awareness of the initiatives on an informal level throughout the whole watershed. The results of the investigations enabled water quality guidelines to be established for the upper catchment. To achieve the guideline levels additional initiatives were developed including a scheme to manage mine water discharges into the river system, the development of a standard four-step water management process, investigation and development of innovative mine water treatment processes, specifically sulfate reduction technologies, the use of gypsiferous mine water for irrigation, river and dam hydrological models, groundwater models and biomonitoring. Significant outcomes from the process have been achieved including the improvement in water quality in the Witbank Dam catchment. Equally significant have been the development of partnerships between businesses and between businesses and the community specifically in the use of mine water for irrigation. The plan realised a number of requirements for success including, the development of trust, openness and transparency with information, the essential need for consultation and negotiation and the involvement of third parties to validate information. The future still holds the potential for disputes between upstream and downstream water users but understanding, transparency and accountability between all players have, and will in future, enable the matching of the increasing demands on a scarce water resource to the needs of all.

Jan 1, 2003

By Ma F, Yang Q, Ujihira M

The effect of stresses and acoustic emissions on the gas permeability of coal was investigated in the field and the laboratory in order to find an estimative method of the practicability of gas drainage. In the field, acoustic emissions and gas emissions during gas drainage drilling were monitored tentatively at some coal mines in Japan and China.In the laboratory, acoustic emissions from coal specimens in addition to gas permeability were measured during the triaxial compression loading in order to interpret the results monitored in the field. Besides, the opening of gas permeation channels in coal was considered on the basis of the experimental results.

Jan 1, 1991

By Taylor L. M

Accurate computer prediction of the muck pile produced by a conventional blast requires modeling of the physics that occurs during the rock motion phase of a blast. The ability to predict the motion and the subsequent muck pile can have a significant economic impact on the mining industry. Some of the computer programs previously used to predict rock motion employed polygonal elements with comers and sides to model the rock (Cundall, 1971; Walton, 1982; Taylor, 1983). This approach allows the elements to bulk because of the corners and the aspect ratio. However, tracking the many interactions of the comers and sides of the elements is a computationally intensive process. Several other rock motion computer programs were developed that employed spherical elements, (Schamaun, 1984; Gorham-Bergeron et al, 1987) but they lacked correct bulking mechanisms or could not be vectorized for efficient execution on vector processing machines. A new spherical element code called DMC (Distinct Motion Code) (Taylor and Preece, 1989a, 1989b) has been developed this past year. DMC was designed and written to take advantage of super-computer vector processing capabilities. The efficiency has also been increased through the use of spherical elements, explicit time integration and a new contact search algorithm. When spherical elements were chosen for efficiency, some physically correct mechanisms for capturing the bulking behavior of the rock mass also had to he developed. This paper will treat several mechanisms that were developed to allow spherical elements to exhibit correct hulking behavior.

Jan 1, 1990

Spatial continuity as described by a variogram is a reflection of the underlying mineralisation/geology. Modelling of the spatial continuity (variogram) must account for both the quantitative data (ie sample grades), on which the variogram calculations are based, and the qualitative information as provided by the geological interpretation. An understanding of the geology and the variogram interpretation tie together the sample values and allow us to go beyond the actual data (Journel, 1995). Variography makes geology transportable and allows the geological interpolations to be channelled downstream into mine planning, ultimately affecting the economic decisions surrounding a deposit. As such the process of variography and resource modelling is critical. Thus consistent expert decisions need to be made which force geologists to have a closer look at the available information and the geological interpretations. The aim of this paper is to provide an overview of the latest developments in visualising variography and to demonstrate their usefulness in decisions regarding the spatial continuity of mineralisation. New ideas concerning potential future developments in visualising and modelling spatial continuity through variography are introduced.

Jan 1, 1996

By Gillies A. D S

The paper presents a review of research in the area of explosible coal dust with respect to safety in the underground mining environment. Research over the last several decades has concentrated on generating dust clouds in small scale laboratory explosion chambers to study flammability limits and the physical and chemical variables which affect explosion propensity. The validity of this approach is discussed and the results obtained for a range of coal types compared.

Jan 1, 1994

By Laas JJ, Spearing AJS

Considering the capital outlay, running costs and inherent difficulties of backfilling operations at depth the benefits need to be clearly established, quantified and then exploited. Expansion of Vaal Reefs Exploration and Mining Company towards even deeper, highly faulted ground, and the process of establishing codes of practice for the management of rockfalls and rockbursts, required that a sound support strategy be formulated. This paper describes the derivation of an overall backfilling strategy on Vaal Reefs. Use was made of experience gained over some 12 years with backfilling. Numerical modelling was used to estimate potential benefits of backfilling the deepest mining areas still to be extracted. In exploiting a probably unique opportunity, two contiguous mining areas bounded by the same major geological structures, were compared. One was extensively backfilled and the other not at all. Shaft sinking through a backfilled stope added another dimension to the database. Backfilling was introduced in 1985 and several potential spin-offs were expected. These included improved local strata control for fall of ground and rockburst conditions, regional benefits in rock mass stability and mine ventilation optimisation.

Jan 1, 1998

By T C. Hunter

There are unique risk factors involved in the development of an Australian uranium project especially by a æjuniorÆ. These encompass a range of political, technical, environmental, regulatory, timing, native title, investor relations and financial issues. The Honeymoon Uranium Project in South Australia is being developed by Southern Cross Resources. The history and experience from a risk viewpoint is detailed and discussed. Particular emphasis is placed upon the practical experience and obstacles overcome to meet project milestones.

Jan 1, 2003

By Samyguin VD, Filippov LO

The aim of this paper is to emphasise the importance of knowing of the rate of the elementary flotation acts (EFA) - attachment and detachment. By studying the simplest linear model notion of the column flotation, the results of the nonlinear simulaton of flotation separation in the column with lengthwise upward mixing show two principal different types of separative mass-transfer in the column. The first is, the case of a small EFA intensity, almost without the detachment. The second is, the case of a big EFA rate, when the process is close to a local attachment-detachment equilibrium. There is also an attempt to estimate the EFA rate for three different kinds of quartz particles, floated by cation collector in the laboratory column apparatus.

Jan 1, 1993

The paper describes a computer model developed within the State Electricity Commis- sion of Victoria for use in open cut planning. The purpose of the model is to simulate all the typical occurrences in, and influences on, the coal supply and overburden disposal systems in order to be able to assess their performance. The model incorporates much of the long term and day-to-day operations planning logic required for the allocation of resources within an open cut. This logic takes account of power station demands, bunker stocks, plant and crew availability, the balance of reserves between dredgers, planned maintenance, etc. The perfor- mance of plant within the system is simulated using random selections from statistical distri- butions of Time to Failure and Time of Failure for each plant item. The application of the model in selecting a suitable bunker capacity in a notional open cut development is described to illustrate the potential of the model in optimising plant selection.

Jan 1, 1982

By Stone AM, Romensky G

The requirement for economic operation of unit trains carrying bulk materials has dictated that rapid and accurate bulk loading methods be provided. The train loading station at Phosphate Hill, built for Queensland Phosphate Ltd. to load rock phosphate, provides this facility and whilst the concept used is not unique, it contains a number of novel features that are considered to advance the "state of the art'' in this field. This paper briefly reviews some alternative concepts evaluated, and describes the design and operation of the scheme ultimately selected as being most appropriate to the project requirements. it is one which utilises a variable speed belt feeder whose speed is controlled in proportion to the weight rate of material moving on the belt as measured against a set point

Jan 1, 1978

This paper will examine the prospects for Queensland's non-fuel mineral industries as we approach the 21st century. The opportunity for growth is unprecedented. Exploitation of recent discoveries, proposals and developments in downstream processing are predicted to contribute to a doubling of the State's mineral exports to around $10 billion by the year 2000. In 1995 - 96 the value of Queensland's mineral production was $6 billion, comprising $1892 million metallic minerals, $127 million non-metallic minerals and $4 025 million total fuel minerals. For many years Queensland has been among the world's major producers of copper, silver, lead, zinc, bauxite and mineral sands. Recently Queensland has become an important producer of magnesia. Queensland's ability to compete results from its location close to rapidly developing Asian markets, the diversity of its major minerals and an increasing ability to add value to the resources base using competitively priced energy. Northwest Queensland is one of the richest base metal provinces on earth following the recent discovery of five world-class orebodies. Of these deposits, Osborne (copper-gold) has commenced production and Cannington (silver-lead-zinc) and Ernest Henry (copper-gold) are scheduled to be developed by 1997. Century Zinc Limited and the Queensland Government are negotiating with native title claimants on the development of Century (zinc-lead-silver). Expansion is in progress at the Mount Isa copper mine (renamed the Enterprise) and copper smelter and a high analysis fertiliser project may be developed based on Phosphate Hill. Korea Zinc Company Limited has reached agreement to construct and operate a 350 000 Mtpa zinc smelter/refinery near Townsville. There are future expansion prospects for the vertically integrated major industrial mineral operations based on Weipa bauxite and Kunwarara magnesite. Upgrading of the Boyne Island aluminium smelter will require a doubling of alumina consumption. Downstream processing options for Kunwarara magnesite are being investigated and are expected to lead to increases in production and the manufacture of a range of value-added products. At the Yabulu refinery near Townsville, nickel and cobalt production using imported ore is to be increased and a commercial cobalt plant is to be built. Additional opportunities for further processing and manufacturing are associated with proposed new mines at Ely (bauxite), Skardon River (kaolin) and Goondicum (ilmenite). Recently discovered resources of zeolite and perlite also offer exciting development possibilities. Other manufacturing opportunities such as glass and ceramics based on local and plentiful clay and silica sand could replace imports. Silica sand at Cape Flattery is currently exported and production is expected to double.

Jan 1, 1997

By Goodheart B

The Australian Mineral Sands Industry has expanded from the initial export of mixed concentrates in the 1930s, through various development stages, to its current position as a leading world producer of individual mineral products and some further processed products. Opportunities for downstream processing of the separated minerals and locating such developments in Western Australia are reviewed, along with the role of the Western Australian Government in assisting resource development projects.

Jan 1, 1986