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Grey River Gold Mining Ltd commenced dredging alluvial flats in the Grey River Valley in 1989. Previous drilling indicated over 100 million cubic metres of gravels with some 90 per cent of the gold in the bottom seven metres. The dredge built by Rahco, Spokane, was innovative in a number of aspects but particularly in the fact that a separate ladder with a cutter and pump was used to strip the overburden and a bucketline to mine the gold bearing wash below. Metallurgical studies and exploration were initiated when the project commenced. Leasing and environmental considerations were investigated and action taken. While progress is being made, the operation at this stage is not meeting required production and performance. Main problems have been with the stripping system and wear.

Jan 1, 1990

On the basis of the data known on formation, characteristics and stability of solute heavy non-ferrous metals under different temperature and pressure conditions and different concentrations of substances dissolved it is found to be possible to obtain a condition of mineral formation resulting in selective production of free-floating minerals. This process of forced mineral formation has been taken as a basis of new methods of refractory copper raw materials concentration, complex processing of lead dust from copper smelting plants, lead flotation tailings final concentration and of those of polymetallic ores concentration. This list of effective utilisation of the process is not exhaustive (Bekturganov Abishev and Shkodin, 1987; Bekturganov and Sim, 1987; Bekturganov, 1988; Abishev and Bekturganov, 1989; Bekturganov, 1989a). To understand the character of the sulphurising thermodynamic and kinetic examination have been done. Analysis of conditions of the newly formed mineral associations formation and stability facilitates the elaboration of methods of improvement of results of the valuable components selective separation.

Jan 1, 1993

By I Gipps

The mining industry has come through a period of major change in community expectations regarding safety and environmental impact and these changes can be expected to continue in the future. These changes are ultimately reflected in Government regulations and industry safety standards and form the basis of the ælicense to operateÆ. Equally, advances in technology have made possible new equipment and processes either available now, or close to completion, that will allow mines to meet these more stringent expectations if properly introduced. Changes in technology provide opportunities for mine management to introduce new systems that will remove people from hazardous areas and lead to improvements in the ætriple bottom lineÆ. In a longer time frame of five to ten years, novel and advanced technologies that are currently being developed will deliver new mining methods and conversion of presently uneconomic resources to ore. This is consistent with the time frame required to develop a new mine from discovery. Strategic decisions can be taken now by mine designers to enable the introduction of these major technology changes. Examples of both practical and strategic opportunities are drawn from the integration of rock cutting/blasting, automation, electronic communications and new mining methods. This paper discusses emerging industry trends, changes to legislative framework and some practical choices for existing and imminent technology.

Jan 1, 2003

By C Sennersten, A Hellicar, C Lindley

Traditional methods of resource modelling and mine planning rely upon geostatistical methods applied to exploration drill core data to derive a three dimensional model of the distribution of metal grades, quantised into rectangular prisms or blocks. The resulting block model is a primary input into short, medium and long term mine planning. However, block attributes are averaged or interpolated over a complete block, meaning that information at smaller scales is lost to the mine planning process. Grade engineering for new mining methods, such as the development of more accurately controlled blast designs, continuous miners for hard rock and sensors for rock properties that can be distributed along the operations process and value chain, allows excavation to be much more selective than traditional blasting, and provides data for driving earlier separation of waste from ore. This selectivity can be optimised if the resolution of resource models can match or exceed the spatial resolution of selective mining technologies. Opportunities for selective mining increase as a deposit becomes more heterogeneous. This leads to an interest in methods for estimating the distribution and characteristics of mineral heterogeneity within the ore-body. The objective of this work is to present some definitions of mineral heterogeneity, and to explore how heterogeneity as defined can be measured and inferred within ore-bodies.CITATION: Hellicar, A, Sennersten, C, Lindley, C and Evans, B, 2018. Heterogeneity assessment for grade engineering in complex ore bodies, in Proceedings Complex Orebodies Conference 2018, pp 11–13 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

An experimental study of the influence of surface active agents on the dewatering of fine coal was undertaken with a view to evaluating the usefulness of such materials in reducing the residual moisture contents of filter cakes. Experimental evidence is presented which suggests that while polymeric fiocculants have a beneficial effect on settling, they can have adverse effects on the filtration of the thickened underflow. Detergent addition, on the other hand, was shown to reduce filter cake moisture, and the magnitude of this effect was determined, in part, by the prevailing electrochemical equilibrium at the solid-solution interface.

Jan 1, 1976

By V Narayanaswamy

SustainabilityÆs imperative of economic development in tandem with social advancement and environmental protection is widely accepted, but much debate remains about the practical implications for the minerals processing technologies and practices for the future. Experience in other industry sectors however suggests that sustainability can be a value-adding framework for innovation in processing technologies, business models and management systems. This position paper explores how sustainability can drive innovation in minerals processing, by reviewing pertinent ideas and experiences gained in non-minerals sectors. Sustainable innovations can generally be broadly ranked from incremental to transformative, with each category having its own typical improvement potential, timescale and technological and operational challenges. This leads to a æmud mapÆ for sustainable innovation in minerals processing with three distinct tracks: eco-efficient operations; sustainable plant design and sustainable processing. Competing models for the sustainable innovation process through either forecasting or back-casting, have in common the strong reliance on vision, perspective and competency, which in turn highlights the importance of sustainability frameworks. Such sustainability frameworks provide normative goals and option elicitation prompts to assist with the analysis of current processes and scoping of more sustainable alternatives. A comparative analysis of five prominent environmental sustainability frameworks revealed three cross cutting sustainability themes that challenge current resource processing technologies and practices. These are: fate of materials (zero dissipation of materials); compatibility of materials and processes; and materials intensity of industrial products and processes. Although the sustainability concepts presented in this paper have not been extensively road tested in the minerals processing industry, there is ample evidence that recent initiatives in the Australian resource sector illustrate the applicability of the proposed framework. It is therefore argued that more in-depth assessment of sustainable innovation concepts would be a valuable contribution to the sustainable resource processing theory and practice.

Jan 1, 2004

By Grant JR, McKavanagh BM, Dear SJ

A geophysical technique of rock mass assessment for engineering purposes is being investigated and shows positive correlation with direct structural logging and mapping techniques for the detection of major geological features. The technique is cross-hole acoustic surveying incorporating high speed signal averaging, with a maximum hole separation in excess of 30 metres in hard unfractured rock masses. The bulk of the field test work was carried out in open stopes in the copper ore bodies of Mount Isa Mines Limited. The investigation forms part of an integrated study of blasting in mining, aiming for fragmentation control through blast design modification. The rock quality factor, Q, is presented as a blasting index and can be determined for a significant portion of a production stope.

Jan 1, 1981

An account is given of experimental apparatus for generating a short duration high velocity water jet and the effect of its impingement on various rock samples under air or water cover. The penetration was found to be highly dependent upon the rock structure; in general material with closely interlocking grains was resistant.The damage sustained by a stationary sample held close to the jet did not vary greatly whether the sample was in air or confined under a water layer; but when the sample was translated under the jet there was a marked increase in the damage sustained.Some consideration was given to the possible practical application of a water jet for deep hole drilling and an estimate made of the power requirements and transmission losses for such a system.

Jan 1, 1969

A novel problem-solving exercise for undergraduates is described which is directly relevant to production supervision. It is based on the fictitious Metwin Plant which produces refined metal from sulphide concentrates via a hydrometallurgical route with six unit operat- ions. Students are given details of the chemistry, process engineering and normal operating conditions. They are also given min- imum data for the Plant when it is operating with a fault. By requesting further data, for which they are 'charged', the students must diagnose the fault. The responses of students to the exercise are described. The data were produced by computer simul- ation of steady state operation under normal and various faulty conditions. The development of this program was an educational experience for the author and it stimulated new interest in metallurgical process engineering.

Jan 1, 1984

The explosion of a charge in a drillhole sets the surrounding rock mass into vibrating stress wave motion. Except in the immediate vicinity of the drillhole, the dynamic stresses associated with this motion do damage only to pre-existing joints, cracks, or other weak planes, not to the rock material in between these. The joints are weak in tension, therefore the damage occurs as a result of tensile stresses. The initial damage process in the rock mass that ultimately breaks loose in front of the hole is similar to that in the remaining rock behind the drillhole. Recorded or calculated values of the vibration velocity and frequency contain a wealth of information about the combination of stress and strain that causes the damage. This paper outlines a new technique by which the peak strain energy derived from measured or calculated vibration velocity records is used to determine the local fragment size distribution. It combines two previously known and well tested techniques, namely the Holmberg-Persson calculation of the peak vibration velocity generated by an extended charge and King's calculations of the fragment size distribution as a function of the strain energy in rock crushing. Both of these calculations are based on experimental data and have been tested and found to agree well with actual conditions in their respective fields. Holmberg-Persson's calculated peak vibration velocities have been used successfully to predict and control damage to the remaining rock in cautious blasting, while King's calculation successfully describes the comminution of rock in mechanical crushing. Preliminary predictions of fragmentation in two types of rock blasting, a large hole open pit mining blast and a tunnel round, indicate that the new technique for fragmentation prediction has the potential for predicting fragment size distributions within the rock removed by the Blast.

Jan 1, 1995

Low displacement fault zones often comprise a mesh of interlinked faults, extensional-shear and purely extensional vein fractures. Hydrothermal mineralisation localised around such structures testifies to their importance as conduits for fluid flow. Mesh structures are most commonly developed in situations approximating bulk pure shear but predominantly simple shear meshes also occur. They appear to develop through the infiltration of pressurised fluids into a heterogeneous rock mass with varying material properties. In some circumstances, mesh formation appears to be a precursor to the development of major through going faults. Mesh formation generally involves hydrofracturing (Pf > s3, at least locally) and the condition Pf ~ s3 to be maintained for the mesh to remain a high permeability conduit, requiring fluid over pressuring at other than shallow depths in extensional-transtensional regimes. The volumetric character of earthquake swarm activity appears to result from the passage of hydrothermal fluids through mesh structures, representing a form of distributed fault-valve action along suprahydrostatic hydraulic gradients arising from magmatic intrusion, compaction overpressuring, metamorphic dewatering, etc. Fluid redistribution in the crust is influenced by maximum hydraulic gradient (not necessarily vertical), by existing permeability anisotropy arising from bedding and other forms of crustal layering, and by structural permeability developed under the prevailing stress field. Strong directional permeability develops in the s2 direction, parallel to fault-fracture intersections within the mesh and orthogonal to fault slip vectors. In particular tectonic settings, stress-controlled permeability allows strongly focused flow through fault-fracture meshes with high potential for mineralisation. Favoured localities for mesh development include short-lived link structures along large-displacement fault zones such as dilational jogs, lateral ramps, and transfer faults.

Jan 1, 1995

According to the Australian Bureau of Statistics, fatalities from road transport accidents represented an average of over 97 per cent of all transport related accidents between 1997 and 2002. With increasing traffic density, tunnels are becoming a more viable means of providing alternative travel routes to ease areas of congestion in the road transport network. However, unlike open road conditions, a fire incident in the confined space of a tunnel environment may impact upon many users that are remote from the incident location. In this context, designing for an appropriate level of safety in tunnels is therefore an important consideration for achieving consistency in the life safety measures for users of the road transport network. Unfortunately, like fire safety engineering design for buildings, there are presently no clear measures in the design processes to assess the adequacy of the design in terms of attaining the level of safety implicated in the design objectives. This is partly due to the indeterminate nature in which the design objective or the level of performance measure is stated û the intent of the objective is relatively clear but the measure of it is not. Another reason is the lack of a standardised procedure for determining the critical design variables affecting life safety. This is important to ascertain consistency in the use or adoption of the important parameters for design. This paper looks at the processes involved in the fire engineering design of road tunnels that are currently practised. A review of the design processes for fire safety in road tunnels is provided, which includes the range of fire scenarios in a tunnel environment, the traffic flow and composition, the relevant fire protection systems, the ventilation and smoke control system, the egress provisions and the benefits of incorporating fire brigade intervention. A simplified risk assessment approach is developed for a typical road tunnel to assess and evaluate the impact of a range of design parameters on life safety. Using a sensitivity technique, the important variables are then identified and means of reducing design variations associated with them are recommended. The technique may be further refined for use in the development of codes or guidelines in order to develop a suitable means of deriving more consistent design values, and hence achieve better consistency in the overall level of safety in the design.

Jan 1, 2008

The stratigraphy of the Singleton Coal Measures is reviewed and a revised stratigrapixy which has been ratified by the N.S.W. Standing Committee for Coalfield geology is nominated and defined by a selected type section. Withir the type section the occurrence of repetitive phases are illustrated and described. Coal. Measure units within the Singleton Coal Mean sures, termed the Wollombi and Wittingham Coal Measures respectively, are correlated with the Newcastle and Tomago Coal Measures. In formal nomenclature the Singleton Coal Measures are designated the Singleton Super Group. The major depositional cycles within the Coal Mea- sures are outlined together with those lesser phases within the Coal bearing sequences that influence the mining conditions likely to be encountered. Both tectonic and sedimentary features of the Singleton Coal Measures are considered and the localized post depositional effects on the coal seams and roof strata in- duced by differential, compactions are emphar Sized.

Jan 1, 1972

By Lawson F

Chrome chemicals are commercially produced by the alkali roasting of the chrome-bearing ore chromite with sodium carbonate. In order to ascertain the influence on the extent of reaction of the replacement of Mg(II) for Fe(II) in the chromite spinel structure and the presence of acidic oxides in the gangue material, a series of roasting experiments was conducted using chromite materials from a number of different locations. The roast feeds and products were chemically analysed and the major compounds identified using X-ray diffraction and scanning electron microscope techniques.Mg(II) replacement for Fe(II) in the chromite structure does not appear to restrict the amount of "available" chromium for reaction.Under the test conditions, namely an atmosphere of pure oxygen, finely ground chrome-bearing material, a roast temperature of 950°C and the stoichiometric amount of sodium carbonate to react with the chromite, the yield of water-soluble sodium chromate was able to be expressed as %yield = 104.5 -1.58 × %AI2O3 - 2.23 × %SiO2 for chromite samples containing alumina in the range 7.8 to 27.8 per cent and silica in the range 2.9 to 7.4 per cent.

Jan 1, 1984

By B Mil, D P. Adhikary, M S. Craig, P Rutzou

As shallow coal reserves with easier mining conditions are exhausted, future deep coal mining with difficult mining conditions may face significant economic, technical and environmental challenges. Moreover, due to increased coal production capacity with the new generation longwall systems, predicting adverse mining conditions has become more important than ever before. The potential impact of these difficult conditions is an increase in mining risks and costs. Reliable prediction of rock mass deformation, mine stability and mine water inflow is not only essential for improving mine safety and reduction of coal production costs, but it is also important for the assessment and management of the environmental impact of mining. This paper briefly describes an integrated approach to mine groundwater simulation and prediction. Central to this integrated approach is a three-dimensional computer code called COSFLOW, developed by CSIRO of Australia in collaboration with NEDO and JCOAL of Japan to address the pressing issues of mine water management. COSFLOW incorporates unique features that make it ideal for the simulation of coal mining and examining the interaction between rock fracture, aquifer interference and water flow. This paper also presents an example of an application of the integrated approach and COSFLOW in water inflow prediction at Springvale Mine in New South Wales.

Jan 1, 2006

By Brown K, Francis D

The Yallourn Open Cut Mine has recently commenced mining operations in the new East Field which will supply the 1450MW Yallourn W Power Station for the rest of its 30 year design life. The authors describe the design and implementation process followed during the rehabilitation of the areas disturbed by works associated with mining in the East Field. One area of the East Field, the old external overburden dump, has been of particular interest and is discussed in detail. A discussion on the fire protection considerations is included as these are critical and often misunderstood as being contrary to good rehabilitation design practice. Finally, the development of a master plan for the rehabilitation of the Yallourn Open Cut in general, incorporating the East Field work, is discussed.

Jan 1, 1992

By M Stewart, J Vann, S Dunham

Geometallurgy is an emerging, cross-disciplinary field that integrates spatial models of rock properties with time-based outcomes of mining and treatment processes. Geometallurgical variables include any rock property that has a positive or negative effect on the business. Some of the more critical geometallurgical variables include recovery, grindability, throughput, power consumption, mineralogy and content of deleterious materials. These variables drive project costs and revenues in a fundamental way and thus geometallurgy has potential to positively impact on the value of strategic and tactical decisions across many mining organisations. Geometallurgical models, like traditional grade-only models are based on samples collected from the mineralised and non-mineralised regions of the deposit. The nature of some non-grade variables, particularly those that are dependent on the ore treatment processes, requires special consideration during sampling and subsequent spatial modelling. Failing to objectively consider the characteristics of variables may seriously compromise the validity of the sample selection, sample treatment, data models and the subsequent decisions. In addition to addressing the vexed question of collecting an æunbiased and representativeÆ sample, the sampling and modelling approach must consider issues of scale, both geostatistical support and also the relationship between bench-scale data and operational-scale mineral processing performance. This paper proposes a framework (the Primary-Response framework) for the classification of geometallurgical variables. This framework is designed to assist with developing sampling approaches and identifying the most appropriate spatial modelling approach. The proposed framework can also help identify the risks associated with designing, sampling and modelling of both types of geometallurgical variables. The Primary-Response framework divides variables into two categories; primary variables and response variables. How a variable is classified in this framework depends on the degree to which the variable reflects either an intrinsic attribute of the rock (æprimaryÆ) or its response to measurement processes (æresponseÆ). Depending on the classification in this framework, appropriate sampling and modelling decisions can be made to minimise the risk associated with the incorrect treatment of the variable. In particular, the authors argue that for response variables, the approach taken to building spatial models may need to be different to conventional linear averaging approaches (for example kriging).

Jan 1, 2009

The difference between a hypothetical and a theoretical approach is considered and the advantages in using a hypothesis is discussed. Virgin horizontal stresses play an important role in stabilising strata which bridge across an excavation, and reduces the tensile stresses which develop in a beam subjected to bending. Simple formulae are deduced for the bridging of a thick massive stratum under such conditions. At shallow depths, tensile failure on the upper side of the beam is the most likely cause of fracture, but below a certain depth this gives place to compressive failure on the underside, with the possible incidence of rock bumps. The presence of strong massive beds delay the onset of subsidence and may restrict the width of the subsidence trough. If the material involved in the caving is strong, this will reduce the final subsidence, especially at shallow depths. The British regulations for the control of aquifers and their dependence on the strain developed at the seabed are discussed. As an alternative, the concept of a disturbance factor is introduced to permit the consider- ation of aquifers at depth, leading to an explanation of the make of water on the first faces to be mined in the Selby Coalfield. 'Elie paper closes with a brief consideration of the different roles played by longwall face supports in the control of readily cavable strata, and the control of strong beds which hold up in the waste.

Jan 1, 1986

City Resources Limited selected Vanuatu as a target area for epithermal gold mineralization because of its relatively unexplored character and its location on the southwest Pacific rim. During 1985 a systematic program of reconnaissance prospecting was completed on six islands within the Vanuatu group, using a helicopter and a specially designed exploration support vessel with on-board assay laboratory. Within a period of 4 months, reconnaissance prospecting of all six islands was completed, two previously unknown epithermal gold provinces had been discovered, and six major prospects warranting detailed exploration had been identified. Factors which contributed to the success of the program include (i) a flexible management approach, (ii) the mobility and access provided by the support vessel/helicopter combination, (iii) rapid assay turn-around, and (iv) adherence to basic prospecting techniques. The relative merits of various sampling media are discussed.

Jan 1, 1987

The subject of steel wire ropes covers such a wide range of points that it would be impossible to deal with it fully in one paper, and in view of the apparent scarcity of published information on the subject it is proposed in this paper to deal with those items which should give the mining engineer a better understanding of the basic factors which affect the design.selection, and use of ropes. The matter will be considered under the following headings:-1. Brief history of steel wire rope-making.2. Rope-making terms.3. Wire rope materials.4. Characteristics affecting economy, operating life, and serviceability of a rope.5. Properties of construction of rope, and stresses met with in wire ropes.6. Drum and sheave sizes and sheave bearing pressures.7. Storage, handling, and maintenance of ropes in service.8. Common factors affecting rope life, particularly winding and haulage ropes.9. Inspection of ropes.GENERALWire rope, which was invented for, and first applied to mine winding, has become an indispensable aUXiliary throughout the whole field of mining, be it for underground, open cut, or dredge work, as well as the requirements of transport and treatment of ores.Though wire ropes appear simple collections of wire and fibre, the demands made upon them are many, and the stresses and abuses to which they are exposed in service are varying, and often of serious dimensions.The exposition of these stresses and abuses, particularly dynamic stressing, corrosion, etc., all of which seriously affect the safety and economical life of the ropes, is often enough to frighten most practising mine staffs, who are aware that before the requirements of economic operation stands the still more important question of safety in mining.

Jan 1, 1947