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By A G. Grice

Surface disposal of mining processing wastes is usually perceived as an undesirable consequence of meeting societyÆs needs for metals and minerals. Environmental disasters associated with the discharge or storage of such wastes, though infrequent, can have very damaging consequences for the environment and the industry. Reducing or eliminating the potential for such events may be achieved by placing some or all of these processing wastes back into the voids created by the mining operations. Processing operations may limit or enhance the opportunities for using tailings and other waste products as a backfill material. Backfilling is a truly multi-disciplinary process and requires the informed involvement of mining, metallurgical, engineering and environmental specialists. This paper describes the range of fill types currently being used in Australian mines, particularly those utilising processing wastes as constituents. It focuses on how processing operations can affect the suitability of these materials for the various types of fill, the resulting fill properties, fill performance and costs.

Jan 1, 2002

A contract for three 20 ft diameter vertically mounted axial flow fans of the same aerodynamic design, was placed by Mount ]sa Mines Limited in 1963. The hydraulic blade pitch changing mechanism, the method of blade fabrication, and the roll out centre casings are features of these fans. Protection devices and fan control are designed for unattended operation and remote control. The erection and commissioning of the fans during 1964-65 is described.

Jan 1, 1967

Mineral resource and ore reserve classification defines the risk associated with quoted resource tonnes and grades, allowing the interested party to make a judgement as to the `worth' of the resource statement. The JORC Code and Guidelines (1992) are now well entrenched as the foundation upon which gold and base metal deposits in particular are publicly reported. There are three categories of resource, namely Measured, Indicated or Inferred reflecting decreasing levels of confidence. The ore reserve, that is the economically mineable part of the resource, is classified as Proven or Probable and can only be drawn from the Measured and Indicated resource categories. As summarised by Stephenson (1995), resource/reserve classification has been an issue ever since the earliest days of mining in Australasia where, like elsewhere in the world, the industry, for a long time, lacked firm reporting guidelines. Those currently adopted in Australasia as the minimum standards for companies reporting to the Australian Stock Exchange (ASX) have been developed and revised since 1972 by The Australasian Institute of Mining and Metallurgy (The AusIMM), the Australian Institute of Geoscientists (AIG) and Australian Mining Industry Council (AMIC). Debate is now underway in terms of adopting an international code. The Code specifically does not attempt to regulate either the classification technique nor the method of estimation of the resource/ore reserve, but rather places the responsibility for this task on a `Competent Person' whose experience will decide the appropriate approach for a given commodity/orebody. The Competent Person must be a Corporate member of either The AusIMM or AIG with five years experience `relevant to the style of mineralisation' under consideration.

Jan 1, 1996

The relative contents of Au in a series of groundwaters from water bores and exploration drillholes, located near Au mineralisation at Stawell, Ararat, Clunes and Ballarat in central Victoria, were found to be clear indicators of relative proximity to mineralisation in each region. In the same series, waters with anomalous concentrations of As distinguished Au mineralisation in bedrock from secondary palaeochannel or deep lead Au. In some groundwaters, acid pH values, high sulphate relative to other anions and detectable concentrations of reduced Fe reflected sulphide minerals associated with bedrock Au deposits. Close to some ore zones, locally anomalous groundwater concentrations of Mn reflected the Fe carbonates that accompany Au in these zones. In addition, elevated concentrations of other elements provided geochemical signatures for the aquifer lithologies associated with Au mineralisation. Of the lithological indicators Co and Ni, U and F, Rb and Cs, Mo and Li respectively reflected the mafic, felsic, potassic rich and quartz zones, principally in the Stawell mine area and to a lesser extent those at Clunes and Ballarat. Mineral stability diagrams, based on groundwater activities of K', Mgt and H`, demonstrated that a series of ore-zone groundwaters follow a trend that conforms with a biotite to sericite to kaolinite alteration sequence in aquifer mineralogy. This is a good illustration of how present day groundwaters under surface conditions can reflect the underlying mineral sequences that accompany these Au deposits. These observations around mine areas suggested that groundwater chemistry could provide a rapid and cost effective method of assessing prospectivity for An of extensive areas in central Victoria. To test this, regional sampling and analysis of 355 bore waters was carried out in a region where potential An bearing rocks are covered by Mesozoic and Cainozoic sediments and volcanics. Contoured elemental abundances and distribution from this program indicated five zones in which groundwaters had elevated Au and despite the cover, appeared to reflect variations in the underlying Palaeozoic rocks. Three of the Au zones could be in terrain affected by extensions or intersections of faults, a feature in common with the established Au deposits in central Victoria. Reflections of concealed Palaeozoic rocks included a possible zone of concealed Cambrian greenstones that coincides with three of the Au zones. It was concluded that each of the An zones represents a groundwater Au focus that warrants follow-up exploration.

Jan 1, 1997

By Lorenzen L, Van Der P F

It is the aim of this paper to review recent research in understanding the role of cyanide in the elution of gold. Under conditions of severe pre-treatment (high temperatures and levels of cyanide), the dynamics of elution are determined mainly by the adsorption equilibrium and the flow conditions in the column. When conditions are less favourable for desorption, transport phenomena are rate controlling. The most important sub-processes of elution are the changes in cyanide, potassium and gold concentrations, as well as the change in passivation of the carbon surface. Mathematical models to simulate the various sub-processes are described briefly.The presence of an irreversibly adsorbed species such as AuCN on the carbon is determined mainly by the pH, temperature and the type of carbon. Cyanide in the pre-treatment step will convert the AuCN to reversibly adsorbed Au(CN)2. Competition between cyanide and Au(CN)z for adsorption sites will enhance the elution of gold, but plays a minor role at elevated temperatures. The most important effect of cyanide is its reaction with the functional groups on the carbon to passivate the surface for the adsorption of anionic metal cyanides and thereby promote the elution of gold. This passivation, caused by the degradation of cyanide, is strongly temperature dependent. Free cyanide in the elution step of an AARL elution is of lesser importance than the cyanide in the pre-treatment step. Elution without cyanide is possible only after cold acid washing, and has been proven on plant scale.

Jan 1, 1992

By Lyman GJ

Systems for the routine on-line determination of ash content of process streams in coal preparation plants and handling systems have been in use in Australia for over four years. More recently, monitors for on-line moisture measurement have been developed to complement the ash measurement function. The technology for these systems is reviewed briefly. The development of reliable ash and moisture monitors has made the implementation of automatic systems of coal quality control practical. The emerging philosophies of automatic control in Australian preparation plants are examined with particular emphasis on systems involving dense medium circuit regulation. Related developments in flotation control and coal sorting are noted to complete this overview.

Jan 1, 1987

By Motyka J, Adamczyk AF, Witczak S

A case study of migration of a paper factory fluid wastes, on the distance of 5 km from an underground disposal site to an ore mine is presented. The ore mine in question, situated in SW Poland is pumping 3.5 m3/s (ca 300 000 m3/day) of groundwater, producing a cone of depression about 150 m deep and several kilometers wide. The migration of wastes (pollutant) occurs within the carbonate karstic aquifer of Triassic age. The aquifer is about 100m thick and is characterized by the coefficient of hydraulic conductivity equal to 8 m/day on the average. The results of systematic measurements carried out for 13 years enabled to estimate the mean breakthrough curve of the pollutant. On this basis and taking into account the coefficient of hydraulic conductivity as well as the mean hydraulic gradient between the disposal site and the ore mine, the migration parameters of the polluting material, i.e. the real flow velocity, the effective porosity and the longitudinal disper- sivity have been calculated. As the measurements considered a long migration distance of the pollutant, the obtained hydrodynamic dispersion constant (dispersivity), in the authors opinion, is reliable enough to be applied for regional groundwater calculations, regardless of the "scale effect".

Jan 1, 1988

By Chugh Y. P

A generalized void diffusion model for subsidence prediction has been developed based on theoretical concepts and physical principles. The general form of the model is a three-dimensional differential equation. With a few assumptions on the characteristics of overburden strata overlying typical room-and-pillar mining or longwall mining systems, specific solutions for the differential equation were obtained. A brief description of these solutions and their applications in the United States and China are presented in this paper.

Jan 1, 1992

For the past five years the University of Queenslandhas, through its various workshops, been preaching to Australia that there was a potentially hazardous situation from earthquakes for urban Australia. A few people outside The University accepted this, but largely the warnings fell on deaf ears.The 1989 Newcastle earthquake changed that per-ception. The most important lessons to emerge from Newcastle were (i)the realization that in continental areas small earthquakes cause widespread damage:(ii)the local geology of an area is of great importance in the damage done by an earthquake.These two factors clearly indicate that, in the future, we must take far greater account of the "Urban Geology" of an area. This paper discusses the need for urban geology and its impact on seismic risk and compares that with the traditional methods of assessing seismic risk.

Jan 1, 1990

By D P. Obeng, L Reemeyer, R Holmes

The Zinifex Century Mine employs a large number of Detritor mills for fine and ultra-fine grinding to liberate silica and sphalerite at 80 per cent passing 7.5 microns before final zinc flotation. A joint project between CSIRO Minerals and the Zinifex Century Mine was carried out to evaluate the Detritor mill performance. Plant surveys were conducted around the Detritors in conjunction with laboratory tests. The survey data showed that the Detritors in the ultra-fine milling circuit performed well. They reduced a feed F80 sizing of 46 microns to a product P80 sizing of 7.5 microns at a gross energy consumption of 37.2 kWh/t. Scale-up of ultra-fine milling Detritors was studied using a 0.55 kW laboratory batch unit and a 355 kW full-scale Detritor by processing Century zinc concentrate with 1 mm sand media. The results indicated that the 0.55 kW laboratory mill underestimated the energy consumption of the full-scale Detritor by about 20 per cent for a product P80 of seven microns. The performances of a horizontal IsaMill and a vertical Detritor were compared as ultra-fine milling devices for processing Century zinc concentrate. The experimental data demonstrated that, when using the same grinding media, the energy efficiency of the two mills is similar despite the difference in mill designs. The Detritors used for regrind duty at the Century Mine performed poorly when processing feed at 80 per cent passing 88 micron. The energy consumption was high and the product size distribution was broad with particles above 100 microns in the feed unbroken and particles below ten microns overground. A coarser ceramic media of 3 mm was therefore tested in a laboratory Detritor to process the regrind Detritor feed as an alternative to the 1 mm Colorado sand used at the Century Mine. The ceramic media reduced the energy consumption significantly and produced a narrower product size distribution, which is more desirable for the downstream flotation process.

Jan 1, 2007

The high cost of sampling systems is largely due to the fact that indiv- idual mechanical type sampling units must be installed at the discharge end of ore/pulp pipelines, that is, at points where the pipeline discharges into pump sumps or the like. A considerable economic advantage may be obtained in the use of a samp- ling device that can be installed at any point in the path of the trans- porting pipe line. Initial tests on a vertical line with an injection sampler using iron ore concentrates reveal the validity of this type sample versus that taken with a mechanical sampler. A descrip- tion of the injection sampler shows its simplicity of installation, requir- ing minimum downtime on existing lines.

Jan 1, 1976

By Baafi EY, Chatterjee PK

The quality of mine planning decisions ultimately depends on reliable estimates of the characteristics of the orebody. The quant- ifiable factors such as grades or thickness can be estimated from field data gathered from outcrops or exploratory drillholes. Since outcrop data is necessarily limited to the periphery of a deposit, extensive drilling generally is required. This paper outlines a method for selecting the number and location of additional exploratory boreholes using an iterative procedure based on a mathematical optimization concept called fixed point theory. The method is illustrated through its application to an exploratory drilling program for a coal mine where optimized locations gave a lower estimate of regional and block variances than a manual Choice.

Jan 1, 1986

By Wu Y. H, Lu J. P

Slope stability has now become a practical tool in the design and oper- ation of open pits. The stability of rock slope depends on many factors, including not only structural geology, the existence of weak layers, ground- water, blasting and weathering, but also the virgin stress field. This paper presents an application of a numerical method to investigate the effect of the virgin stress on slope stability. The finite element method is employed to simulate the excavation of open pits. Redistributed stress fields in the slope of open pit are computed for several different virgin stress fields. Based on the redistributed stress fields, the shear force which tends to produce sliding of a rock mass and the frictional resistance to sliding are evaluated. The possibility of potential failure is assessed by the limit equilibrium method. The combination of the finite element method with the equilibrium method provides a powerful analytical tool for slope stability. The significant effect of virgin stress on the stability of slopes is shown by studying a typical case.

Jan 1, 1989

The development of the Australasian Code for Reporting of Identified Mineral Resources and Ore Reserves is a significan step towards informing the financial community and the public about the future profitability and risks of investing in resource companies. The Code is also important from the accountants' point of view because it provides them with a well-defined bash for assigning costs or attributing value to the assets of resource companies and hence improving their financial reports. Although reporting to the public is ultimately the responsibility of management, accountants, like geologists, are frequently required to provide information for inclusion in these reports. Jr the last ten years, there has been a considerable refinement in the reporting of mineral resources which can be attributed mainly tc the progress made towards developing the Code. It seems tha the classification and terminology that the geologists have developed are widely used in the annual reports. However, little progress has been made by accountants in improving the financia information. The purpose of this paper is twofold: (a) to outline briefl) some of the major problems in accounting and reporting fo; mining companies and; (b) to examine the potential contribution of the Code in solving those problems.

Jan 1, 1990

Degussa's PAL-system (peroxide assisted leach) has been proven to be more economical than the conventional cyanidation technique. Significant in- creases in the gold recovery have been reported, accompanied by savings in cyanide. Accelerated extraction kinetics and modified reagent demands necessitate a redesign of the conventional cyanidation plant. The South African Osprey Mine is presented as an example of a successful PAL-application. Based on the plant and laboratory data it is shown that the redesign of the flowsheet can be an important factor for the effectiveness of a metallurgical plant. In the case of the Osprey Mine, the PAL-technology all ows a modification of the current preoxidation-ClPcircuit to two separate CIL-plants to treat run-of-mine ore and old tailings dumps. A doubling of the throughput is possible without enlargement of the plant. This innovation in the field of gold extraction, the combination of the PAL-process with a redesign of the metallurgical plant, can be considered as a basis for a more profitable gold mine.

Jan 1, 1991

By Drain P, Dibdin T. R

THE completion of the Linda incline man and supply haft at the Mount Morgan Gold Mining Oompany's mine led to an investigation of the various safety gears in general use in mining shafts. One of these gears completely fulfilled the necessaryconditions. This paper endeavours to give a description of the man car and safety gears now operating in the before mentioned shaft, together with the main considerations leading to their design and sub equent adoption. Fig 1 diagramatically shows a longitudinal section of this shaft.

Jan 1, 1911

The objective in design of an excavation in a jointed rock mass is to achieve a prescribed degree of control of rock mass displacement around the excavation. Any excavation in jointed rock usually involves slip and separation along discontinuities as well as translation and ro- tation of constituent rock blocks. Thus, any acceptable model of behavior around an excava- tion must be capable of simulating the force displacement paths followed by the constituent elements, including rigid body translation and rotation. The distinct element method models such behavior by simulating the rock mass as an assemblage of rock blocks which interact through corner and edge contacts. Discontinuities are regarded as boundary interactions between blocks with joint behavior prescribed for these inter- actions. Introduction of structural element logic allows a variety of installed support sys- tems to be modeled. The response of the support to axial, transverse, and flexural loads is based on explicit algorithms similar to those used in the distinct element formulation. This allows large displacements and rotations and general non-linear constitutive behavior for both the support elements and the interface with the rock. This paper describes both the distinct element and structural element formulations and demonstrates several applications involving sup- port interaction with jointed rock.

Jan 1, 1987

In the stability assessment of open pit walls, geotechnical engineers have to deal with uncertainty related to structural geology, rock mechanical parameters, groundwater and so on. This uncertainty will immediately and significantly impact on wall stability assessment and therefore. influence mineral recovery and ultimately the financial return of open pit mining. However, the conventional factor of safety applied to measure the stability of slopes and the relevant analytical computer packages cannot quantitatively consider the variability or uncertainty of the input data. As a supplement, therefore, geotechnical engineers have begun to apply probability to the stability assessment of open pit walls over the last two decades. To-date unfortunately, no powerful computer package is available to geotechnical engineers to conduct the probability analysis of slope stability. This paper presents a computer package of probability analysis for rock and soil slope stability. In this computer package, the strength parameters of rock and/or soil material such as cohesion, friction angle and unit weight of the different rock and/or soil type domain in a complex structural geology environment can be considered as the basic input random variables. Groundwater level can also be taken into account as a random variable in this package. Two `rigorous' limit equilibrium solutions, the Morgenstern/Price method and the Sarma method, can be used to calculate the factor of safety during Monte Carlo Simulation applied in this program. Five types of probability distribution are included in this package for the user to simulate basic input random variables. Two realistic cases from BHP Iron Ore are used to illustrate this package.

Jan 1, 1997

Three key areas of C.I.P. plant design, viz. leach- ing time, adsorption and the gold loading on the carbon, are discussed and illustrated with examples. The need for accurate pilot plant data for use in assessing and optimising design is emphasized. This approach should minimize capital and maximise return on capital. It is demonstrated that, as regards adsorption, economics favours short retention time, high gold loadings and mechanically agitated, draft tube reactors. INTRODUCTION Little attempt appears to have been made in Australia to design the present generation of C.I.P. plants to achieve an economic optimum. Most would, seem to have been based on pre- liminary leaching data, gold extraction and value and rule of thumb which, in general, has led to over design and over capitalisation. An essential step to effective economic design is a comprehensive pilot plant study to establish definitive operating parameters, yields and reagent costs. In most cases the cost of developing this data will be more than offset against capital savings in plant; the operating profit should be increased substantially, and profit is maximised for known

Jan 1, 1982

By K Sanematsu

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Ore deposits of rare earth elements (REE) in South-East Asia are classified into four types: carbonatite, allanite, ion-adsorption and placer. Occurrences of the carbonatite deposits are confined almost exclusively to the Red River Fault Zone of northern Vietnam. Since the carbonatites contain dominantly REE fluorocarbonates (eg bastnasite) and lesser amounts of monazite, they are rich in light REE but poor in heavy REE. The ion-adsorption type deposits and prospects were found in Myanmar, Vietnam and Thailand. The ion-adsorption ores generally show lower REE grades than those of the carbonatite type and placer deposits; however, they could be enriched in HREE, which are more precious and scarce commodities than LREE. The ores consist of weathered granites with a significant amount of ion-exchangeable REE, which are extracted by using a dilute electrolyte solution. The ion-exchangeable REE are likely to be sourced from REE fluorocarbonates, allanite and titanite because these minerals are relatively susceptible to weathering and release REE3+ ions into soil water. In contrast, monazite and xenotime are resistant to chemical weathering and could form placer ores. Placer monazite and xenotime have been processed as by-products of placer Sn, Zr or Ti in Malaysia, Thailand and Indonesia, although the current production is small.CITATION:Sanematsu, K, 2015. Rare earth element deposits and prospective areas in South-East Asia, in Proceedings PACRIM 2015 Congress, pp 671–678 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015