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By K Le Bron

Fatalities that occurred because of rock falls in off-reef excavations (excluding shafts) over the last three years range between ten per cent and 20 per cent of the total number of fatalities that have occurred due to rock falls in the South African mining industry. These rock falls, mostly exacerbated by blasting practices, occur because of failure on discontinuities within the rock mass. Among other reasons of their occurrence is insufficient support installation or the incorrect assessment of rock mass conditions. This report presents qualitative analysis intended to outline rock stability conditions in tunnels subjected to dynamic loading. Seismic waves including those created by firing an explosive charge in tunnel rocks are considered. The rock behaviour is monitored using geophones and extensometers variably installed to record the near and far effects of roof bolt support units on a dynamically loaded rock. The paper discusses the results of field investigations.

Jan 1, 1999

By R Yong, A McEwan, D G. Miljak, D Milinkovic, A Curtain, P J. Coghill, R Stefulj, B Lovric, G Roberts

The CSIRO has pioneered the development and use of certain classes of magnetic resonance (MR) for mining applications. The MR technique is a radio frequency-based spectroscopy that provides highly quantitative measurement of selected ore minerals. MR has many inherent advantages for bulk sensing in mining applications, including deep sensing penetration into most bulk ores with the use of non-contact sensors that are robust and tolerant of demanding mine conditions. The highly discriminating nature of the technique also provides the very desirable attribute of robust and simple calibration, that can often be performed prior to sensor installation. Rapid sensing (within seconds) at very low grade (few hundred ppm Cu) has been demonstrated, as well as sensing at high tonnage rate. Besides sorting applications, MR may also be applied to preconcentration applications involving very large volume sensing including: (i) haul truck sensing using portal arrangements, where truck destination assignment may be dynamically determined based on the truck grade, (ii) in-pit gantries used for loading trucks that may similarly be equipped with sensors for truck assignment and (iii) deep mine bench sensing, recently progressed through a CRC ORE project, where local bench grade is determined at the few-metre lateral scale and at depth prior to blasting, to aid selective blasting and ore extraction. MR sensor prototypes have been developed for each of these applications and have been tested in laboratory or limited field conditions. To inform the value proposition for truck or bench sensing, initial analysis of truck assignment improvement based on an analysis of in-situ mine bench grade has been performed for a porphyry style deposit. The prototype sensors, preliminary results and future technology development and objectives will be described.

Nov 10, 2020

An algorithm is described which leads directly to a unique set of coal washing parameters which, in two or more parallel streams, will give maximum yield of product at a given ash. This occurs when all parallel streams are washed to the same incremental ash. This strategy is shown to offer a considerable increase in yield compared to the simpler strategy of washing each stream to the same sumulative ash.

Jan 1, 1987

By Dunlop G. A, Cantrell R. A

The metallurgical and engineering requirements that form the basis for planning column flotation Pilot Plant testwork are reviewed. Pilot plant operating issues are discussed and a basis for the testwork program formulated. The application of the testwork results to engineering design and scale-up is briefly reviewed.

Jan 1, 1992

By M L. Habner, S D. Munro

In a gold CIP/CIL circuit, adding new circuit water to a final tails thickener and then directing the thickener overflow to the head of the circuit significantly reduces the cyanide concentration at the TSF discharge spigot. The new water is used to dilute the final tails. The dilution and recycle of the tails in this manner may have the added benefit of reducing reagent consumption, in some cases to the point where the reagent savings justify the expenditure and Cyanide Code compliance is achieved at no extra cost. Potential circuit configurations and water recycles can be modelled by splicing a flowsheeting and thermodynamics package, such that changes to the composition of the water can be reduced to chemical speciation with a Gibbs free energy minimisation enabling a complete understanding of the circuit water chemistry.

Jan 1, 2007

By Meakins R. L, Talaska A, Kenny D, Haycraft J. A, Dickson B. L

A vehicle-mounted radiation detector interfaced to a microprocessor called PRAM (programmable radioactive analyser mobile) has been developed to provide grade control for selective mining of a soft rock uranium ore. The grade of ore over which the vehicle passes is determined and indicated by several coloured lights to a pegman who walks behind the vehicle. Coloured pegs are then laid out to mark the uranium grade ranges on the floor of the mine pit. Comparison between grade ranges determined by the PRAM and by prior drilling and downhole logging at the Yeelirrie deposit, Western Australia indicate good agreement. Use of the PRAM decreases the cost, manpower and time required to grade extensive areas of a mine pit floor.

Jan 1, 1982

The various functions of public relations are playing an increasingly important part in the activities of the many companies now engaged in oil exploration in Australia.Several of the larger exploration companies, notably West Australian Petroleum Pty.Limited, Ampol Exploration Limited, Caltex Oil (Australia) PtSr: Limited and Australian Oil and Gas Ltd. (and its American Associate Union-Kern), employ staff or consultant public relations specialists. In, most of the other companies now exploring in Australia, public relations are handled within the company, directed from the highest executive level.The object of public relations in.the oil industry is. to create in the public mind an impression favourable to the industry as a whole and'the company -or group of companies with which the public relations officer is associated.

Jan 1, 1962

The purpose of this paper is to outline the current status of financing in the Australian Gold Mining industry and to discuss a number of developments that have occurred during 1983/84.Recognising the importance of equity financing various equity issues, including project valuation, will be discussed against the backdrop of an industry experiencing both rapid growth and a changing structure.Nothwithstanding the current tax exempt status of the industry there is a trend towards more debt financing. A number of financing issues will be covered and it will be shown howvalue can be created through astute financing planning.

Jan 1, 1984

The rnunber of Cenozoic volcanoes which has already been found in China surpasses 600. An ancient Chinese tourist, Xu Xiake (1587-1641 in the Ming Dynasty), mentioned in his travel notes the volcanoes and hot 'springs in Tengchong, a country of the Yunnan Province, 400 years ago. In 1927, the geologist, Yun Zhanli, expounded generally on the recent volcano distribution in China. In the '70's, China not only accomplished aerial photography and produced topographic and geological naps covering the whole country, but also obtained a new understanding of the geographic distribution and process of development of the Cenozoic volcanoes through Landsat imagery; interpretation and ground verification, together with C14 isotope dating and analysis of volcanic rocks.

Jan 1, 1987

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

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

Jan 1, 1995

An extensive railway construction prog- ram in the People's Republic of China has required the excavation of many tunnels in difficult ground, particularly in mountainous regions. Conclusions drawn from case histories permit guidelines to be formulated as to the optimum location of tunnel alignments in faulted and folded terrains, and also in karst regions. Geological factors adversely affecting durability of tunnel linings can be minimised by adoption of appropriate construc- tion practices.

Jan 1, 1987

By D Manhire, G Hogan, M Ryan, S Whiteley

Site restoration at the L&M Mining Limited alluvial gold mining project at Waikaka near Gore, Southland is described. In 2000 mining operations started to recover alluvial gold beneath historical dredge tailings over 244 hectares in the flood plain of the Waikaka Stream. The project had an eight to nine year mine life but was prematurely closed in 2002 because of economic considerations. Restoration of the site back to pastoral farming, with shelter-belt and amenity tree, shrub, and wetland plantings is described. Dealings with the landowners and regulating authorities are addressed in the paper.

Jan 1, 2003

By Conley R, Payne I

The Vickery Coal Mine commenced open cut mining operations in May 1991. All overburden and interburden is drilled and blasted for excavation by dragline or hydraulic excavator. The mode of operation adopted from the feasibility studies requires that throw blasting of the overburden be used to assist dragline productivity.This paper reviews the development of the drilling and blasting practices with particular emphasis on the throw blasting of the overburden and optimisation of costs. This review includes analysis of the pre-production drilling and blasting feasibility studies by comparison with actual results.

Jan 1, 1992

The design, construction and operation of a 500,000 tonne per year Carbon-In-Pulp (C.I.P.) plant at Kambalda embracing the period from 1980 to 1982 has been previously discussed (Sceresini, 1982).Since that time the annual throughput rate has increased to 780,000 tpy.This paper discusses the changes and improve-ment made to allow this increased production to occur with minimal capital expenditure.

Jan 1, 1984

By Masters I. M, Ozberk E, Chalkley M. E

The integration of iron rejection as hematite with the Sherritt two-stage zinc pressure leach process has been investigated on the laboratory scale. The two-stage pressure leach process is applicable for a greenfield zinc plant, or for replacement of the conventional roast-leach circuit in an existing zinc plant. An excess of zinc concentrate is used to accomplish acid neutralisation in the first stage of pressure leaching, and the residual concentrate in the first stage residue is treated with an excess of acid solution in the second stage of pressure leaching to yield high zinc extraction. Integration of hematite precipitation with this process allows for the potential sale of the iron residue, greatly decreasing the residue disposal problem. Two flowsheets containing the desirable features of both of these processes are described in this paper, along with laboratory Results.

Jan 1, 1993

Most internationally traded iron ore resources are derived from multiple mine sites, transported to a port facility where they are blended and possibly further processed prior to shipping. Provided the proportion of contributions varies over a number of shipments an estimate can be made of the bias introduced by mine site sampling, analysis and materials handling systems, using zero-intercept multiple linear regression. Further regression applied to the residuals allows the error variances for the source mines to be estimated. Various sampling strategies are used by the industry. All have shipment-loading sampling on which payment or at least provisional payment is based. In most cases sampling prestockpile is used at mine sites to verify estimated production grades. Train grades are estimated from mine stockpile grades and in some cases train grades are verified by port input sampling. The methodology used is presented in this paper. Simulated data have been used and do not reflect the actual performance of any operator. The merits of the various systems and the implementation and potential limitations of our method are discussed more fully in a companion paper (Ziegelaar and Everett, 2010).

Mar 1, 2010

By Johnston G, Revy T

Dominion Mining Ltd. and the JKMRC have conducted a detailed investigation of the performance of two of Dominion Mining's gold treatment plants (Haveluck and Paddy's Flat). In terms of design each plant is considerably different. The Paddy's Flat plant uses a single stage SAG mill with recycle crusher, followed by single stage ball milling. The Haveluck plant uses the more traditional approach of multi-stage crushing and ball milling. The performance of these two plant designs in terms of energy efficiency and cost of comminution equipment, developed at the JKMRC, to accurately predict both power draw and size reduction characteristics at these plants is evaluated.

Jan 1, 1991

By testing rotary-drag bits in granodiorite it was found that an increase in bit clearance angle from 241 0 to 33° decreased insert wear. Severe wear has precluded economic application of rotary-drag drilling in abrasive rock even though fast penetration rates have been achieved.From a limited number of tests and from theoretical considerations, the insert wear was inversely proportional to the thrust on the bit This effect follows the marked reduction in the linear distance traversed by the inserts, for a given depth of penetration, as thrust increases...

Jan 1, 1969

By Adranyl W. W

Sub-level caving with bottom ore drawing has gained wide acceptance in rich, soft, low magnetic iron ores because it provides moderate ore dilution and ore losses. The main problem here is the high rock pressure exerted on sub-level drives situated in the sub-level sill pillars. To reduce this effect, the ore block is divided into panels. This paper illustraes the method of determining the maximum panel width providing low maintenance cost of sub-level drives.

Jan 1, 1995

By E House, V Lisitsin

Recent whole-rock geochemical data from nearly 900 fresh drill core and underground samples taken from seven central Victorian gold deposits confirm the presence of distinct and identifiable primary alteration haloes surrounding the deposits. Ferroan carbonate alteration extends for up to several hundred metres away from turbidite-hosted gold mineralisation outside of contact metamorphic aureoles. A less distinct phyllic alteration zone can be identified using geochemical molar ratios or short wave infrared analysis. It generally overlaps a sulfidic halo characterised by disseminated pyrite and in close proximity to mineralised structures, arsenopyrite. The extent of the sulfidic halo can be traced using low-level analysis of pathfinder elements such as S, Au, As and Sb. Recognition of these alteration features enlarges the target for exploration and provides a tool by which drilling can be directed towards mineralised structures. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008