Search Documents

By Van Rooyen F

An introductory review of the current grade control blasting techniques (selective mining strategies) used in the Eastern Goldfields has recently been undertaken. The survey was initiated and conducted by the Western Australian School of Mines. Four distinct selective mining strategies have been identified and a number of trends have been highlighted. Many operations, however, have developed techniques which use a hybrid method to suit the site conditions. The aim of all the mining strategies is to produce an optimum product. The optimum product is one which contains no diluent and experiences no mixing of the various identified ore and waste blocks and is fully reco- vered at the minimum overall operating cost. Due to this unified aim all of the grade control blasting techniques have many common design Features.

Jan 1, 1988

With the evolution rate of technologies, earthmoving equipment users are establishing vision statements for their operation out to and in some cases beyond 2000. Autonomous systems are receiving a lot of 'press' - and rightly so, as they hold a potential for achieving quantum leaps in productivity and cost gains. Caterpillar feels that it is important that the infrastructure of on-board systems are understood and can be utilised more in the near term to `grow' a user up to the stage of autonomous operation.

Jan 1, 1997

Coal mining safety and health legislation is more than typical of safety legislation which has been born of adversity. Indeed, in the main it has been the child of disaster. Requirements which now appear obvious were indeed only occasioned by either social injustice or more commonly by great disasters. Even then changes were often made only after months or years of deliberation by committees. Early mining legislation in New South Wales benefited from the experience in Great Britain. The pioneers of our industry were miners from there and brought with them the basic British legislation, so we started with knowledge gained the hard way. A review of accidents statistics provides a measure of the effectiveness of mine safety legislation, but unfortunately rules cannot control human nature. Miners, managers and inspectors must work as a team to make mines safe and new legislation in New South Wales is planned to this end.

Jan 1, 1975

By Ingham PD

Selection of equipment for a mining operation, such as Mount Isa Mines, requires certain parameters to be correctly defined. Management control is essential for monitoring, improving and future purchase of equipment. Some research is being done independent of supply manufacturers. Observations about future outlook are made.

Jan 1, 1982

The mined-out Old Waite volcanogenic Cu-Zn deposit lies in the Noranda mining district of northwestern Quebec. The deposit has a distinctive pipe-like zone of alteration beneath the massive ore, extending into the stratigraphic footwall. The hydrothermal metasomatism within the alteration pipe produced a concentric zonation. with a peripheral quartz - sericite - chlorite mineral assemblage surrounding an axial core of magnesian chlorite - Phlogopite.

Jan 1, 1989

Conditional simulation is a branch of geo- statistics which allows the simulation of a mineral deposit so that predictions can be made about the variability of some particular parameter of the deposit. A summary of the general principles, advantages and limitations of conditional simulation is presented together with an example based on coal seam thickness.

Jan 1, 1981

By S Bluhm, R Funnell

Creative mine-designs are constantly being applied in the deep platinum mining industry in South Africa. Recently, this has resulted in deep hot mine-designs including room and pillar, bord and pillar or stall and pillar layouts and the use of in-stope trackless mechanisation. In these mines, the ventilation systems use refrigerated air and high fan pressures and as a result ventilation leakage can have a huge impact. Leakage is a serious impediment to cost-effective operation and potential leakage in future projects is a major factor in judging project viability. This paper describes certain mine layouts and quantifies the extent of the leakage. Based on typical field data, a range of seals from ævery poorÆ to ævery goodÆ was defined and used to estimate overall leakage. Within these mine networks the ventilation pressure, temperature and density all vary significantly and with the multiplicity of leakage paths it was necessary to make use of the VUMA-network simulation package. For the examples examined, the leakage was found to be up to 85 per cent for æpoorÆ category seals and up to 50 per cent for ægoodÆ category seals. The total air flow (and refrigeration) requirements grow exponentially with strike distance due to the compounding effects of higher pressure and more leakage paths. It is shown that beyond certain depths and strike distances the leakage will become so great that it will be impossible to operate cost-effectively û even with ægoodÆ seals. Indeed, in these examples the projects were not considered viable in their original format because of the high ventilation-cooling costs and the mine-designs were modified to include footwall drive systems û the cost of which was justified by the reduced strategic risk to operating ineffectiveness due to leakage.

Jan 1, 2005

This work describes preliminary laboratory testwork to study the relative leaching response to cyanidation and thiourea leaching of an oxidised low grade gold ore. The potential of an alternative lixiviant like thiourea to commercial processing of mine dumps is discussed by specific reference to selected case histories. It would appear that on the basis of the available published information, there could well be a case advanced for the acid thiourea leaching of sulphide concentrate tailings being subjected

Jan 1, 1994

A continuing demand for exploration geologists, at a level well below that during the mineral "boom" of 1967-1971, will be highly selective. The exploration geologist must be more than the traditional geologist whose primary function has been detailed description of rocks and their recording on a geological map. He must be capable of 1. reconnaissance recognition of favour= able environments for ore mineral concentrations, 2. application and interpretation of techniques of search and evaluation, and 3. evaluation of economic, technological and political interactions that combine to make an ore deposit. Universities have an obligation to their students to provide them with a saleable skill, to educate them so that they can cope profess- ionally and socially, and to provide a mechan- ism by which education can be a continuing process. Humanistic and social studies, develop ment of communication skills, understanding of economic and management principles, ability to assess rock properties that influence extract- ion and beneficiation, and a knowledge of technological developments and limitations are necessary parts of the exploration geologist's

Jan 1, 1974

The reasons for selecting two stage pebble milling in preference to conventional methods of grinding are discussed. Commissioning of the first section was completed in October, 1969. Improvements in both the operating and engineering aspects were then incorporated in the section commiss ioned in March, 1971.

Jan 1, 1975

By Laird CH

Large quantities of brown coal are excava ted from open cut mines in the Latrobe Valley to fire the base load thermal power stations of the Victorian Electricity System. Most of the coal is removed using bucketwheel excavators which have been modified or specially designed for the conditions encountered. The actual digging efficiency of the bucketwheel excavator is strongly influenced by such factors as wheel speed, slewing speed and tooth design and arrangement. The coal deposit, although not difficult to work, is not uniform and the operation of the machine is influenced by the stability re- quirements of the excavation face.

Jan 1, 1978

By Teniswood CF, Sheppard I, Mason LG

An industry initiated project, sponsored by the National Energy Research Development and Demonstration Council, has worked for two years in developing design guidelines for underground coal mining machinery.Continuous miners and shuttle cars were selected for the initial development of design guidelines as these machines were linked with 7500 lost workdays and 490 reported injuries during the preceding two years.

Jan 1, 1991

By Morrison R. D, Davis J. J, Fraser B, Kojovic T

1991 saw the completion of a three-year $1.1 million research and development program in mineral sands beneficiation, funded in two associated projects by the Australian mineral sands industry through AMIRA, and carried out by the Julius Kruttschnitt Mineral Research Centre. It is believed to be the largest R&D project in mineral sands ever conducted by a university research group. It covered dry plant operation, and delivered several products to the industrial sponsors, including: ò A detailed characterisation of the radiation properties, mineralogy and size distribution of inhaleable dust arising in dry plants. ò New process models of magnetic and electrostatic separators. ò New on-line instruments for elemental assay (in association with AMDEL) and bulk conductivity measurements of dry process streams. ò Demonstration and evaluation of the Magstream magnetohydrostatic separation technology.

Jan 1, 1992

By G Muller, P Larrondo, M C. Godoy

The categories of Mineral Resources and Ore Reserves that may be used for public reporting in Australasia are defined in the current JORC Code (2004). Most internationally accepted codes emphasise the principles of transparency, materiality and competence in classifying resources. They also provide some guidance in considering the impact of data quality. There is no method recommended in the JORC Code to classify a Mineral Resource into the allowed categories of Measured, Indicated and Inferred for public reporting. A clearly defined procedure is desirable for many reasons, including consistency, repeatability and auditability. The demonstrated use of geological knowledge in the classification method is desirable. In deposits with abundant historical data there can be large variations in data type and quality. Quantification of the error of the estimates may also be considered. Ways to formally incorporate such information into the resource classification process are presented as a first step towards establishing an objective, repeatable methodology that allocates resources into appropriate categories based on defined criteria of accuracy and precision.

Jan 1, 2006

By Jiricek F

Legislative change has reformed the licensing process in Victoria. The Mineral Resources Development Act 1990 and the two stage system of licensing with the authority to commence work is discussed. A key part is the requirements of planning consent, being either an Environmental Effects Statement or the issue of a Planning Permit prior to the issue of an authority to commence work for mineral extraction. Examples of recent experience is discussed.

Jan 1, 1997

By A Thornton, D Engelhardt, J Woodg

Grinding is a critical part of nearly all mineral processing operations. It is the largest consumer of energy on the mine site (and thus indirectly a producer of greenhouse gas through the generation of electrical energy at the power station). Since comminution is one of the main consumers of electrical energy worldwide, efficient control of grinding mills is of paramount importance. Mill Auto-Pilot is a control system developed for SAG mills to stabilise load and power and improve the efficiency of control and increase throughput. A dynamic, mechanistic model of the grinding circuit is used to determine circuit parameters which can not normally be measured using conventional instrumentation. The circuit model is built from models of the unit operations (such as conveyors, SAG mills, cyclones, sumps, etc), and so captures the dynamic complexities and interactions of real circuit operation. CSA Mines at Cobar NSW accepted an offer to be the reference site for Mill Auto-Pilot and the system was installed in March 2004. In this application the model is used to predict mill load mass, mill solids residence time and cyclone underflow density. These parameters are used to control mill load, power and mill discharge density. The outcomes of the introduction of Mill Auto-Pilot at the CSA Mine are discussed.

Jan 1, 2004

Controlled recirculation of nine ventila- tion air is becoming an acceptable practice world-wide. A brief review of operating and planned schemes is given which illustrates the various purposes for using controlled recircu- lation in different types of mines. A de- tailed description is given of the operating and proposed schemes on South African gold mines. This is followed by a description of some theoretical and experimental work which has recently been carried out into certain important aspects of controlled recircula- tion. This includes: safety systems, dust filtration, blast contaminant removal, radia- tion hazards and the development of an expert computer program for the design of controlled recirculation systems.

Jan 1, 1988

By Hegedus M

The Hydrogeological Survay of the bauxite mines in Hungary was establisned 30 years ago. The goal of the HS has been to collect the all available date needed to solve the hydrogeological problems of bauxite mines. The results of activity of the HS have been summarized in the annual reports-. This report is going to present a few methods to evaluate the hydrogeological properties of fissured, karstic rock ie. the evaluation of drilling mud losses, the statistics of core samples evaluated by a special computer program for calculation the porosity and permeability of the rocks. An experimental injection test is presented together with the development of a new portable instrument to get signes of the water table change during the injection test in every two second. It can be proved that the flow around the well may be a transient one if the yield of the injection exceeds a definite one (Figure 2.). It was observed that the permeability calculated from the pumping test date may be 1.2-1.6 time higher than it coming from the injection test. A practical example is presented also how to use the results of the HS for designing the dewatering of a new mine together with an analogous computer model to forecast the yield expectable for making the drift tunnel. A suggestion based on the hydrogeological feature has been done for the dewatering without using electric energy (see Figure 3.-6.).

Jan 1, 1988

Mining has long been an important activity for the people of Australia. The Aboriginals used rocks and minerals in their culture many thousand years before European settlement. It was not until 1840 that silver-lead ore was discovered in the Mount Lofty Ranges, and developed as Australia's first metalliferous mine.

Jan 1, 1995

By Reid JG, Cutfield S

Considerable quantities of dissolved nickel are lost in the waste liquors from the QNPL nickel treatment plant. Cementation, precipitation and ion exchange techniques were investigated to reduce this loss. Ion exchange was the most successful of the procedures studied and a process for recovering nickel from stripped ammoniacal process liquors was developed in the laboratory and scaled up to plant flow volumes. The system developed uses a carboxylic ion exchange resin operated in a completely ammoniacal cycle. The regenerant is itself regenerable using existing plant, thus the only loss is the stoichiometric value of NH4+ required to displace the exchanged cations from the resin. Existing plant sand/anthracite filter beds have been adapted for use as resin columns containing 3 cubic metres of resin capable of treating effluent at a flow rate of 6000 litres/min.

Jan 1, 1978