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By Snowdowne J. B H

Rand Mines, Limited, located in Johannesburg, Republic of South Africa has recently completed feasibility studies which have lead to the initiation of two major coal strip mining ventures. A minicomputer based mine planning system was developed to perform the feasibility studies. The broad approach of this system is to utilise inter.-actively the specialist skills and interpretative abilities of mining engineers and geologists. This paper reports briefly on the outline of the system and at greater length upon certain aspects of its use.

Jan 1, 1977

Stability on surface mining projects is primarily controlled by five factors. These include structural geology, the most important of the factors, the existence of weak layers, primarily clayey gouge or clay infill, groundwater, blasting and weathering. Case examples of stability on many surface mines including some coal mines are presented. The experience and lessons learned are applicable in some way to stability of surface coal Mines.

Jan 1, 1986

An understanding of the importance of the different components that comprise a rock bolt unit is necessary to ensure the proper use of rock bolts as a means of roof support. The various anchors, bolts and plates in use in Australia have been designed and adapted for Australian con- ditions. As mining conditions change, so will the types of bolts in use. This is apparent in the development of chemical anchors and other recent innovations.

Jan 1, 1971

An on-stream iron ore analyser has been developed in collaborationwith Hamersley Iron Pty. Limited for determining the iron content ofboth lump (- 30+ 6 mm particle size) and fines ( - 6 mm particle size)on conveyor belts. The analyser, which is called IRONSCAN, is basedon pair production, and is now commercially available from Mineral ControllnstrumentationLimited (MC!) in Adelaide. It can be mounted underexisting conveyor belts with minimal modifications to the conveyor structure,and the presence of steel cables in the belt does not interfere oncethe analyser has been correctly calibrated. The analyser has been extensivelytested on both lump and fines on the shiploading conveyor at Dampier,and typically the root mean square (Lm.s.) deviation between singleIRONSCAN measurements and conventional chemical analyses is betterthan 0.5070 Fe. It is currently being evaluated on - 150 mm ore from theprimary crusher at Mount Tom Price, and initial result are encouraging.The principal advantage of IRONSCAN is that it provides rapid informationon ore grades. But perhaps its greatest potential is at the primarycrusher where conventional sampling and analysis is very expensive toimplement.

Jan 1, 1988

A brief descri;tioki is given of nuclear power reactors and their fuels. These fuels are made from a variety of uranium compounds such as uranium dioxide, and uranium carbide as well as uranium metal and its alloys. The various processes used to produce some of these compounds from yellow cake are outlined. Using the natural uranium, heavy water reactor by way of illustration, fabrication of fuel elements is dis- cussed and the characteristics of U02 powder required for this partic- ular fabrication are indicated. The flowsheets and equipment presently in use overseas for production of this type of U02 powder are described. Possible areas where improvements might be made to this conventional process are enumerated and some details are then given of the programme of work which has commenced at the A.A.E.C. Research Establishment to gain experience in the general field of nuclear grade UO20

Jan 1, 1968

By K B. Barnard, M D. Urbani

A synergistic solvent extraction (SX) system for nickel and cobalt recovery using Versatic 10 and decyl-4-pyridinecarboxylate was tested with BHP Billiton pilot plant leach solution. Another synergistic SX system for cobalt and zinc recovery was successfully tested using Baja MiningÆs pilot plant leach solutions. Synergistic SX systems have also been developed to separate iron, zinc and copper from nickel and cobalt for Minara Resources and to separate manganese from magnesium and calcium in waste stream for HiTec Energy. The gypsum precipitation problem at the former Bulong operation could have been alleviated using a Versatic 10 and CLX50 synergistic SX system. These synergistic systems have shown high selectivity for target metals over impurity metals and would largely improve SX plant operation. Maintaining a æhealthyÆ organic is very important for efficient plant operation. Careful analysis of plant organic at CSIRO has been used as a tool to pre-empt and/or solve problems in operating circuits. Work performed to assist operators has included assessing plant organic solutions to highlight impurity build-up with time, assessing reagent stability under prescribed operating conditions, correlating organic composition with impurity transfer and crud analysis. An independent estimate has determined that work in this area by CSIRO has provided over $50 M in benefits to the industry.

Jan 1, 2005

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

The Agnew Mine No. 1 Ventilation Shaft is the largest diameter shaft blind drilled in a hard rock mining environment. The selection of this method of shaft development was based on achieving an accelerated mine development and exploration programme. Drilling the shaft from a pre-sink depth of 73m commenced on March 22, 1982 and the shaft was stopped due to rig structural problems at a depth of 750m, 280m from the designed depth, on February 12, 1983, 137 days behind schedule. While problems with rig mechanical availability, cutter life and lost drilling tools in the hole hindered progress and escalated costs, penetration rates above prediction were achieved and both the speed and safety aspects of the method were well demonstrated.

Jan 1, 1983

1880 - 1930 - The Golden Years of Mineral Processing Technology

Sep 13, 2010

By Fabjanczyk MW, Guy RJ, Tarrant GC

The design of the reinforcement systems required to stabilise mine roadways has developed through the application of field measurement techniques. These techniques have allowed the level of security of a given opening to be determined from an assessment of the loading within the reinforcement, the extent of roof deformation and experience. The design systems developed are now used extensively in a wide variety of geological environment. Recent interpretative techniques have been developed to improve the level of confidence when designing roadway reinforcement. The techniques are particularly applicable for roadways subject to either weak materials or extreme stress levels. A second area of application is where roadway advance rates and hence the timing of reinforcement placement are critical. The newly developed techniques include both analytical and computational models. The validated computational techniques allow a more rational approach to investigation of the effect of varying reinforcement type, timing of placement and density on the level of stability achieved.

Jan 1, 1992

There is considerable economic incentive to increase the angle of open pit walls so as to reduce the total volume of waste to be moved to gain access to an orebody. However, a number of slope failures has increased the awareness of mine operators to the potential and consequences of slope failure. Sophisticated methods for the analysis of slope stability have been developed but they rely on an understanding of the appropriate parameters to describe the structural properties of the slope materials. Unfortunately, these properties change with time.The excavation of an open pit mine removes the constraint and weight of the overlying material and allows the newly formed slope to release previously locked in stress. The release of this stress allows the opening of joints and leads to a significant reduction in bulk modulus. The rock mass is also further affected by damage from nearby blasts. Such damage is cumulative and further reduces the modulus of the near surface material and weakens the bonds between structural elements in the slope.

Jan 1, 1992

This paper discusses design concepts in planning a large modern bulk terminal. The need is emphasised for a studied master plan, in-built materials handling flexibility and staged development. An integrated approach is advocated, combining functional purpose designed foundations and structures to serve their mechanical, electrical and environmental functions. Dry bulk and slurry handling are also compared in perspective.

Jan 1, 1983

Digital computers, by virtue of their capacity for high speed repetitive calculation at low cost, are finding increasing application to routine calcula- tions in the mining industry. In this paper techniques are shown whereby the use of computers can be extended to more complex tasks. The regular calculation of grades and tonnages of material to be extracted from specified areas of an operating open pit is a necessary part of production planning. In this paper it is shown how these calculations can be carried out by computer. thereby freeing planning staff from manual calculation. An operating open-pit mine can be described in terms of drill logs, geological ore boundaries and pit perimeters at various levels. These form the data base which must be suitable for frequent updating to incorporate new information. A suite of computer programmes is described which operates on this data base to calculate tonnages and grades of ore within extensions to the perimeters as indicated to the system by planning staff. Possible future extensions are discussed.

Jan 1, 1971

The role of metals in the economy is discussed with regard to the flow of metals through to final demand and is illustrated by data for seven metals. Factors influencing the changing pattern of metal consumption are described, including relative prices. A des- cription and discussion of current metal demand forecasting methodologies precedes a discussion firstly of broad economic trends and secondly of the evolving pattern of metal consumption relative to GDP (metal consumption intensity), as technology and other factors change and as economies mature. The tendency for metal consumption intensity to plateau and decline when economies reach a certain region of per capita GDP, following a rapid rise early in the industrial- ization process, is shown in comparative data for seven metals and six countries.

Jan 1, 1979

Metsim is proving to be a powerful tool when designing a heap leach operation. The most useful outputs arc determining the fluctuations in pregnant solution recovery rate, make-up water rate, gold recovery rate. and pond levels. Detailed data are needed for input: a pad loading schedule, a mining rate schedule for each ore type, column leach test data for each ore type, column tests on water dynamics (ie hourly flow-out versus-in during saturation and drain-down), monthly rainfall and evaporation data, and proposed pond dimensions. These data allow 'what if' studies on application rates, leach rates, loading rates and other variables of interest. Examples will he given of modelling both a rectangular pad and a valley fill operation.

Jan 1, 1994

By Walker K, Burton RC

An outline of the ventilation and refrigeration requirements of deep South African gold mines is presented. This is followed by a brief description of the history of controlled recirculation in mines and the practical and economic benefits such schemes can offer. The potential hazard of a fire in a recirculation system is discussed.The major part of the paper describes the first large-scale field trial of controlled recirculation to be conducted in South Africa. Emphasis is placed on the monitoring system that was used for data acquisition during the trial, and also on a safety system designed to shut off the recirculation fans in the event of a fire.The paper concludes with a review of the latest development work taking place on recirc-ulation safety systems.

Jan 1, 1985

By Kukla G. T

A Seam deposit User oriented Mine Planning System (SUMPS) was developed by The Broken Hill Proprietary Company Limited (BHP) at its head office in Melbourne. It is one of the computer mine planning systems developed by the Corporate Data Processing (CDP) section of BHP. To date it has been employed in the feasibility study of four coal prospects for the BHP Group, including Gregory in central Queensland - Ham and Van Hoorn (1978). It was also used in detailed short term mine planning for Gregory. A recent application was in the feasibility study of Saxonvale, a multi seam coal deposit in New South Wales with seams up to 20 m thick. The other two applications of SUMPS were also on thick multi seam coal deposits. Development of programs for the underground sub-section of SUMPS is continuing. SUMPS was developed and implemented on mini computers with graphics and plotting peripherals. The company's philosophy towards computing is one of centralized development and project planning, with transfer of hardware and software to site once the mine becomes Operational.

Jan 1, 1980

By Luke K. A

Pressure on production at New Zealand China Clays has led to the development of a dewatering control loop for fine halloysite china clay. The development was based on the analysis of data from the automation of plate and frame filter presses. The analysis of the data has led to process changes, and the ability to quickly solve dewatering problems. As a result of control in the dewatering circuit press times have reduced on average 117% and output has increased proportionally.

Jan 1, 1989

High resolution seismic profiling has proved a cost effective tool for defining the structure and seam geometry of Late Cretaceous-Late Miocene age lignite deposits in the South Island of New Zealand since 1981.In 1985 a total of 45 km of Mini Sosie seismic reflection was carried out in the Benhar, Hawkdun and Ashers-Waituna deposits as part of a major multidisciplinary resource investigation funded by the Liquid Fuels Trust Board. For each deposit the seismic programme involved integrating four or more intersecting Mini Sosie traverses with a grid of 1000 m spaced geophysically logged drillholes. The objective was to detect faults, with displacements ranging 30 - 100 m, which might impede mining using bucket wheel excavator systems at depths down to 300 m below surface.In general the quality of processed seismic data was high and with the assistance of ynthetic seismograms and other geological information, it was possible to identify a number of significant previously unknown faults. The success of this seismic programme ha shown that high resolution seismic profiling, used in conjunction with relatively low density drilling, can produce valuable structural and tratigraphic information at an early stage of open pit mining investigation.

Jan 1, 1989

By Quilliam B, Richmond G

Aberfoyle Ltd. has utilised a variety of flotation technologies in the Hellyer concentrator in North-Western Tasmania. Hellyer ore, with its slow flotation rates and low rate differentials between values and gangue, requires the use of long residence times and low air consumption rates in the flotation circuit. The operation of the flotation circuit, with a nominal residence time of 7 hours, has necessitated the development of a control system to provide continuity through operator shift changes. Cell selections at Hellyer varied from the 54 m3 hybrid Dorf Oliver / Maxwell (DO/MX) cells, to smaller 32 m3 Maxwell cells, conventional Don-Oliver 300 (8.5 m3) and 600 (17 m3) trough cells, and a column cell. The advantages of the large cells included low specific power consumptions and a low capital cost. However, problems with mixing and the maintenance of consistent froth depth have been identified in the hybrid DO/MX cells. Short circuiting in the trough cells was apparent, causing a considerable reduction in metallurgical performance. The column cell performs to expectation, although the application is not ideal.

Jan 1, 1991