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By R R LARGE

In the past decade mineral deposit models have become an important tool for the exploration geoscientist. By combining genetic theories on the formation of particular deposit styles, with geological, geochemical and geophysical criteria relevant to ore location, it has been possible to more effectively focus exploration effort to the regions and local targets which have the best chance of success. However, such models have their limitations, and must be carefully and critically applied and continually updated as new technical and research information becomes available.

Jan 1, 1992

By K Hooper

Over the past 20 to 30 years statistics as a science has grown in significance. Not a day passes without reference to the latest statistics by the print, audio and audio-visual media. The Northern Territory Government has been part of this growth and like other public and private sector organisations collects a broad range of statistics. The Northern Territory Department of Mines and Energy participates in the government's statistics collection process. Statistics collected and published by the Department of Mines and Energy include geoscientific; mining and exploration tenure; environmental (e.g. mine site waste water management); production of minerals, oil and gas; mining sector employment; and occupational health and safety. The importance of statistics collection to the Northern Territory Government is discussed in the paper.

Jan 1, 1994

By J O. Watson, V S. Vutukuri

This paper presents results of an investigation on acoustic emission characteristics of granite, sandstone and rock-like material in the unconfined compression and tensile tests. Both the acoustic emission signature and stress-stain curve are analysed in the experiments.The experimental results show that different acoustic emission characteristics are observed at different stress and deformation stages in unconfined compression and tensile testing. Extensive and unstable acoustic emission changes may be interpreted as indicating failure of the rock.

Jan 1, 1999

By D J. Williams, E M. Rykaart

Soil cover systems are routinely used to reduce acid rock drainage (ARD) from mine waste rock dumps and tailings impoundments. A technology for the analysis, design, instrumentation and monitoring of barrier-type (oxygen limiting) and store/release-type covers has rapidly developed and the number of covers under construction has grown extensively during the past ten years. Mine operators are currently investing in this relatively new technology with the expectation that these covers will reduce long-term liability with respect to acid generation, drainage and treatment costs. While the design life for cover systems may extend into hundreds of years, we have less than ten years of construction experience and proven performance. Some cover designs appear to be functioning well; however, the performance of many more is now being called into question. The paper presented herein evaluates the integrity of cover systems from a global perspective. Soil cover systems for the control of ARD are being constructed at mine sites located within high rainfall equatorial regions, deserts ranging from low to high latitude, humid temperate regions, and cold-continental climates. While the technology for analysis and design of soil cover systems is well developed, factors that compromise the performance of cover systems (in addition to the paramount issue of climate) relate to material selection and availability, cost and construction practices. Long-term performance is also strongly affected by physical stability (ie erosion), volume change (ie cracking, desiccation, settlement and freeze/thaw cycling), vegetation, soil evolution and ecological stability. This paper provides a review of the application of soil cover systems for the control of ARD. Cases where cover systems have been constructed with both success and failure are illustrated. General criteria and recommendations for cover selection, design, construction, and maintenance are provided.

Jan 1, 2003

Topography, location of coal bearing land and existing built-up areas severely restrict locations for overburden disposal and dumping sites north of the Latrobe River clear of the coalfields are assumed until internal dumping areas can be established.

Jan 1, 1982

A proved routine mapping practice is described involving detailed observations on grade and structure. The equipment and methods employed are giving good service under the conditions encountered. Stopes are mapped on every floor whether timbered or open, "Kodatrace" workplans and sections being used, and in addition all development whether in country or lode is mapped.INTRODUCTIONThe accumulation of geological data for application to current mining problems and to the search for new ore involves the necessity for close mapping of all available underground faces and backs. The technique which has been developed to suit conditions at the North and British mines of North Broken Hill Limited forms the subject of...

Jan 1, 1940

By James DG, Turner JH

This paper describes laboratory testwork for the beneficiation of a medium grade iron ore, using Wet High Intensity Magnetic Separation (WHIMS). Factors leading to the selection of machine type for this method of separation are discussed and the design of the WHIMS section flowsheet of an iron ore beneficiation production plant are described including methods to achieve operational flexibility and adequate protection of the WHIMS separating chamber. The results of the commissioning and operation of the production plant over several years are described, together with experience developed in plant operation. Data on recovery of hematite over the full range of size fractions treated is presented and compared with data in the literature. Potential methods of improving plant performance are discussed. KEYWORDS: Iron ore beneficiation, plant design, wet high intensity magnetic separation.

Jan 1, 1993

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

By Brenchley R

Partitioning behaviour studies for -particles in the 250 to 1,000 micron size range at. the Curragh coal preparation plant are presented. Plant surveys were conducted to compare the partitioning efficiencies of dense medium cyclones and froth flotation. The aim was to assess the potential for improving yield of coal by directing more of the top size of flotation feed material to dense medium cyclones. ovel mass balancing and model fitting NI procedures were used. While flotation offers high yield of low ash particles smaller than 500 microns, dense medium cyclone rejection .of high ash particles larger than 250 microns is superior. These strengths of the two processes are turned to good advantage by the use or desliming sieve bends which tend to perform some density separation on the'size fractions of interest, directing lower ash material to froth flotation than to the dense medium cyclones.

Jan 1, 1987

The drilling and evaluation of bore cores provides the best available statistical basis for characterizing a coal prospect. Important, long-term decisions by management frequently must be based on the results. The majority of coal mined presently is used for steam raising or the production of metallurgical coke. Common bore core tests and analyses appropriate to this usage can be cate- gorized as non-destructive, chemical, physical, petrographic, caking/plastometric and propert- ies of non-coal material. The major tests within each category are described. Certain specific information from the bore cores is required by the coal geologist, mining engineer, coal preparation engineer and the user, either individually or as a group. The optimal bore core evaluation test pro- gramme is the one which satisfies the needs of all the professional disciplines with the grtatest speed and at minimal cost. The principal steps in such a programme are listed. There is an urgent need for a bold new Australian standard to provide the necessary guidelines to an industry which at present lacks uniformity in its approach to the task.

Jan 1, 1977

Changes in prices and costs change the mineable grade and the profitabil- ity of an ore reserve. In a static world the grade required for an ore reserve is measured by the ratio: Cost/tonne of ore x 100 Price received/tonne of product and profitability by the ratio:- Price received/tonne of product Cost/tonne of product If the words cost and price refer to average cost and average price over some suitable period, say 3 to 5 years, the above ratios express the convent- ional wisdom of the mining engineer, and assume there will be no change in technology or politics.

Jan 1, 1979

By Walter GW

Rock mass classification systems for stable excavation design have been studied. The parameters which are important in such a classification system and those which should be included in a classification system formulated to predict explosive fragmentation behaviour are briefly reviewed and compared. There is significant overlap in the data requirements for excavation design and explosive blast de- sign. Recently there has been a trend to ob- tain some of the data required for excavation design by the use of both field and laboratory seismic investigations. The theory of seismic techniques is summarised and the results of seismic investigations carried out for excava- tion design are reviewed. On this basis it is considered that seismic techniques have the potential to be used for data collection prior to blast design. A programme designed to de- velop such techniques and which includes both field and laboratory experimentation is Presented.

Jan 1, 1978

By Sehic OA

One aim of testwork and flowsheet development is to ultimately provide a reliable and flexible plant that is simple to operate and maintain. Testwork can indicate amenability of ores to CIP treatment and provide a basis for process design and economic appraisal. Batch cyanidation and CIP tests are often sufficient for small projects. Continuous multistage test rigs can be operated to simulate plant operation and to provide data for flowsheet optimisation. Operating requirements, gold recoveries and potential problem areas can be anticipated at an early stage with more confidence. Subsequent project development involving decisions on the basic flowsheet, equipment types and general plant arrangements are based on practical considerations and experience. Computer aided process modeling and economic appraisal can be useful in analysing various tradeoffs, firming up the flowsheet and equipment sizes, and in specifying operating targets for the future CIP plant. INTRODUCTION Carbon-in-pulp (CIP) technology which has developed rapidly since 1974 is now accepted as an economically and technically viable process for the efficient recovery of gold. This paper describes testwork and flowsheet development procedures used for CIP evaluation and design.

Jan 1, 1982

Lithocaps are potentially voluminous zones of advanced argillic and associated argillic alteration located above the subvolcanic intrusive environment. They constitute exploration objectives for epithermal and porphyry-type deposits. High-sulphidation epithermal deposits may be sought within lithocaps, whereas low-sulphidation deposits may exist on their edges. Porphyry Cu-Au/Au deposits may be accessible beneath lithocaps if systems are telescoped sufficiently. Oxidation of the basal, pyritic parts of lithocaps may promote supergene sulphide enrichment under appropriate tectonic and climatic conditions.

Jan 1, 1995

Commissioning is one of the many phases of a project, it has inter-dependencies with the other phases, as they have amongst themselves, and has its own terminology and distinctive features. Commissioning time and cost can severely affect project economics, especially through unrealistic estimating, and requires a separate management team to ensure full control is. maintained. Targets to be achieved in commissioning are identified, together with the necessary policies to achieve them. Factors which have to be taken into account in applying these policies are Discussed.

Jan 1, 1986

Information from bores in the LatTobe Valley has been accumulating for over fifty years, and the manual extraction of details has become a limiting factor in their use.Punched card equipment, installed by the State Electricity Commission for accounting purposes, was known to be available for reasonable periods, and it was suggested that this could help in the extraction of data from the voluminous records.Investigation showed that they could be substantially duplicated on cards, with consequent gains on many operations; the cards being regarded as an auxiliary to the existing records.BRIEF DESCRIPTION OF RECORDSAs a bore is drilled a continuous record of the strata is kept, together with notes on the presence of water or any unusual features which the driller may observe.When coal is struck, samples of each ten feet are usually sent for analysis.The location and surface level of each bore is fixed by surveyors, and details of dates and methods of drilling are also kept.Bores are allocated numbers, prefixed by the name of the parish within which they are drilled. Numbers are allocated in conjunction with the Department of Mines, to avoid duplication.Records of strata and analyses are kept in folders, with 100 bore numbers per folder.Standard plans are drawn, showing the locations, bore numbers and surface levels. For each bore they also show the depth and thickness of coal struck, and the total depth drilled.Cross sections are then drawn, connecting the various coal seams, which have been identified by the geologist.

Jan 1, 1960

By Johns D. R

The producers of mineral sands on the East Coast of Australia might be regarded as having a simple task of selling Rutile and Zircon. Such is not the case. Differing quality and grain size requirements plus the dramatic increase in the percentage of mineral sold in a processed form have meant a large increase in the number of different end products handled. The resulting sales control problems are compounded by the need to be able to deliver against a large number of separate contracts which may relate to spot or long term sales in small quantities or in bulk shipments. Methods of helping management control this situation have been devised and incorporated into a suite of computer programs. Experience with the approach has been very satisfactory. The effect of changes to shipping schedules, commitment to new or changed orders, or proposed changes to production can be evaluated as and when necessary with little bother. Confidence in decisions taken is high since the process of data collection has been designed to involve

Jan 1, 1977

Stope filling practice on the Great Boulder Mine was described in -a paper published in Aus.I.M.M., Proceedings No. 137, in 1945. When the paper was presented the process had emerged from the experimental stage, most of the initial operating difficulties had been overcome, and it had been established that this method of filling was suitable for the working of ore bodies in the Kalgoorlie field: Since 1945, it has fulfilled its early promise, -and during 1947, the tonnage of fill placed was sufficient to cover current operating requirements as called for by the mine ore breaking programme. The object of this paper is to outline current operations. In so doing it will refer' to some ground covered by the previous paper, but will omit details of the initial experimental work. It will include, however, a description of further experimental work on the use of hydraulic filling for worked-out shrinkage stopes, arid will provide more accurate data on costs than were available previously.ESTIMATE OF TONNAGE OF FILL REQUIRED.Early in 1946, the mine ore reserves were analysed in order to estimate the relative tonnages to be mined per four-weekly period by shrinkage stope methods -and by cut and fill stope methods respectively. This analysis was extended beyond the blocks already prepared for stoping, and inclqded the majority of the major ore blocks in the mine ore reserves. It gave the following results:-For a mill tonnage of 28,000 tons per period, 6,933 tons were required from cut and fill stopes, and a possible future maximum programme of 35,000 tons per period would require...

Jan 1, 1948

The first introduction of automatic control systems for flotation occurred about fifteen years ago. The early control work coincided with the introduction of on-line assaying using XRF techniques. This OSA availability, coupled with the emergence of small digital computers suitable for process control in the late 1960-s, meant that the necessary process information and control hardware existed for flotation control experiments. A period of intensive research related to flotation control. ensued. A great deal of effort was devoted to the development of mathematical models of flotation. Plant experimentation sought to understand the effects of a range of flotation variables on the process. Finally, control loops were proposed and plant tested. An evolutionary pattern emerges when the range of flotation control installations is examined. The earliest systems had as objectives process stabilisation using reagent control. There were also some early attempts at flotation optimisation procedures, again using reagent variation. Current work is still associated with the same objectives. One of the difficulties with flotation control has been to recognise and define clear and precise control objectives. More emphasis is now placed on cleaner control which has the advantage that the objectives are usually well defined. A number of flotation control systems which cover a range of control system types is discussed. Based on this accumulated experience,a list of good and bad practice in flotation control is Proposed.

Jan 1, 1983

By Fengyan D

Removing the interference of latter events, the data of geophysical (such as gravity and aeromagnetic) anomalies may indicate whether the mobile belt exist and whether the adjacent terrains of the mobile belt originally belong to one single unit. The petrotectonic assemblage can provide informations about the tectonic setting where it was generated from. The structural style can exhibit the kinetic and kinematic processes. The form of ancient isogeotherm may reflect the ancient geothermal regime which is related to the tectonic mechanism. In general, the early Precambrian terrains suffered polymetamorphism and multiple structural deformation. The researches must be carried out for the distribution of paleogeotharm and m.tamo'phic facies and zones on the basis of recovering the early structural style with structural analysis method; then a relatively correct conclusion may be geined on the ancient geothermal regime. This method can be known as "Ancient Thermotectonic Analysis". Through the sythetical research, a real knowlege about the tectonic setting of early Precambrian mobile belt can be obtained.

Jan 1, 1990