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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 Colwell JB, Cronan DS

Manganese nodules cover great areas of deep ocean floor far from land, and have long been considered a major potential resource of nickel, copper, cobalt and perhaps manganese. A decade ago there was a period of intense evaluation of nodule fields, especially those lying between the Clarion and Clipperton Fracture Zones in international waters southeast of Hawaii. There, nodules are abundant and of high grade (average of 2.4% Ni+Cu+Co). The evaluation activity has since declined, but a recent agreement on lease boundaries among all interested parties may lead to a resurgence of work. Indeed, French and Japanese groups have pushed ahead with field and economic assessments.The Southwest Pacific, where there are large nodule fields in the waters of the Cook Islands and Kiribati, has seen considerable assessment of resources in the last ten years, especially through a major field programme of the Japanese Metal Mining Agency. The best prospect appears to be in the South Penrhyn Basin, in Cook Islands waters, where nodules are very abundant but of only moderate grade (1% Ni+Cu+Co). Using a cut-off of 5 kg of wet nodules per m2, Cronan (1989) and Cronan et al. (1989) have estimated the total resource to be a huge 110 million tonnes of Ni+Cu+Co.

Jan 1, 1990

The interaction of man with the environment has a double character. From one side, mankind can not exist without co- nsuming the natural resources and, from the other side, we actively alter and exert influence upon nature. Analysis reveals that the ecological problem is, to a great extent, a geological one. The paper deals with the application of grouting techniques to construct impermeable barriers for the protection of ground water and soils from depletion and industrial wastes pollution. A number of case histories in the field of mine construction is given to illustrate the solution of geotechnical problems in concert with environ- mental protection measures.

Jan 1, 1988

By C Li, K McDonald an, T Nicholson, C Brown

The relative reactivities of chars prepared from different coal samples at temperatures in the range 500 to 1150¦C were determined by measuring the rates of metallisation of a standard ilmenite concentrate. The results have been interpreted in relation to different measured physical and chemical properties of the chars. Char reactivities were found to correlate with the maximum specific surface area (SSA) of the chars, obtained from plots of SSA versus temperature. Weathering of coal samples gave higher reactivities which correlated with higher SSAs. Experiments using recycled chars showed that the high internal SSAs developed during earlier reduction reactions provide no benefit in terms of increased metallisations. The important role of char hydrogen contents in controlling low temperature metallisation rates was demonstrated. Chars prepared from different rank coals had the same hydrogen content when prepared at the same temperature. Ilmenite metallisation rates had a linear dependence on the hydrogen content of the chars. Large differences in the slopes of the metallisation versus H2 content curves for different chars were interpreted in terms of SSA variations and catalysis of the gas reactions by dispersed metallic iron particles in the chars. A simple test based on magnetic separation of the char was shown to give an indication of enhanced reactivity due to contained metallic iron.

Jan 1, 2001

By M J. Sale

The Epithermal and Mesothermal Gold Prospectivity Modelling Projects recently completed by Crown Minerals provided explorers in New Zealand with a new compilation of historical exploration data combined with new geological information from the GNS QMap 1:250 000 scale mapping project. These data were used to produce predictive mineral potential maps for gold mineralisation in New Zealand. The aim of these projects, which was to stimulate mineral exploration and investment in exploration, has been successful with new companies acquiring new tenements and committing significant exploration expenditure to exploring in New Zealand in the coming years. The projects were undertaken at a national scale and consequently not all exploration data were compiled into the prospectivity models. HPD New Zealand Ltd recognised the value of the prospectivity modeling work and committed exploration funds to continue the modelling process started by the projects. They recognised the need to compile the remaining data and run the models again to allow detailed exploration targeting.

Jan 1, 2004

THE following notes simply sum up the writer's experience, which extended over a very busy period of some three years, dealing with wolfram ores and concentrates. The three methods for the estimation of tungsten that are discussed below are well known, but these results of their trials and comparison under technical conditions may be interesting. Method I. The routine procedure for the assay of rich wolfram ores or concentrates was as follows: Take 1 gram of finely-ground sample; digest with HCl and HNOs for about 2 hours, evaporating down to near dryness. To the remaining 5 cc., say, of liquid, add water, warm or boil for 1 to 1.5 hour, filter through a small filter paper, and wash the beaker and the insoluble matter with hot dilute HCl. It is best to keep the bulk of the insoluble matter (WOs, Si02, etc.) in the beaker at this stage. Then plaee a weighed porcelain dish under the filter funnel and wash the beaker and the filter paper with successive small quantities of strong NHOH, finally bringing all the insoluble matter on to the filter paper, and collecting the ammoniacal filtrates in the porcelain dish (S). Then place the filter paper with the insoluble matter in a porcelain crucible, dry and burn off the paper, cool, and brush the contents of the crucible on to an agate mortar, grind it to flour, and brush this back to the original beaker without loss. In the absence of draughts this can be done safely. Re-treat this residue with' acid and ammonia as above, running the second ammoniacal filtrate into the previous porcelain dish, which in the meantime has been heating on a water-bath.Finally evaporate to dryness on the water-bath the combined ammoniaeal filtrate, and then heat gradually to a red heat over a Bunsen burner, cool, and weigh. Then the contents of the porcelain dish give the WOs (tungstie aeid) direcvly (5).The final filter paper and insoluble matter may be ignited in a porcelain crucible, thus giving the "insoluble matter." If the ore...

Jan 1, 1922

By Komosa T, Muir D. M

Mixtures of ammonia and cyanide at low concentrations leach gold selectively from copper-gold ores. The effects of various reagent compositions on three different ore types containing between 0.3 - 1.5 per cent Cu are reported. It is shown that the results and optimum compositions vary according to the ore, which is attributed in part to the mineralogy and adsorption of solution species on the mineral surfaces. The solution chemistry of the Cu-NH3-CN system indicates that Cu(CN)a - and Cu(CN)3 species are involved in the leaching mechanism. Rotating disc studies on pure gold and copper are reported which show that the Cu(CN)32- species leach gold at about half the rate of CN but leach copper at the same rate. The presence of ammonia retards the leaching rate further. Mixtures of Cu(CN)a3- and NH3 effectively leach gold from Telfer tailing without leaching copper. The role of ammonia appears to be to control the precipitation of copper rather than the kinetics of leaching.

Jan 1, 1991

About 20 percent of world gold production has been contributed by gold deposits in Archaean greenstone belts, of which ca 2100 tonnes of gold has been produced from Archaean greenstone belts in Western Australia (Phillips, in press). These deposits are, therefore, important exploration targets and an under-standing of their nature and genesis can help to formulate exploration strategies and delineate potential targets.A literature survey of Archaean granitoid-greenstone terrains indicates that a wide variety of lithologies host gold deposits. The major part of production from the Yilgarn Block, Western Australia, has come from mafic volcanics andintrusives (70% of production),with significant contributions from BIF-hosted ores (15%) and low production from sediments, felsic volcanics, porphyry intrusives and granitoids (Groves et al., in press). Similarly, most

Jan 1, 1984

A brief introduction is given of the scale and of some special features of South African gold mining; it is noted that great depth of mining and narrowness of the reefs, and hardness and abrasiveness of the rock are the main sources of the problems of the industry. The most inhibiting problems are: Excessive rock pressure occcurring in conjunction with rockbursts, hot and humid working places due to high virgin rock temperature and auto-compression of the air, and low level of productivity. Conventional solutions applied ordinarily in mining do not promise to eliminate, or even alleviate, these difficulties.

Jan 1, 1985

There is a link between the requirements of society and the determination of curricula in tertiary educational institutions. Mineral resources exploration provides a strong example of this link. The resources exploration business engages in scientific, engineering, commercial and management activities in an endeavour to discover economically extractable commodities. Most geoscience and geotechnical graduates are employed by the mineral industry for resource exploration and development. This industry comprises a wide range of employer groups which include the Bureau of Mineral Resources, CSIRO, energy authorities, State geological surveys, State water commissions and private companies. Such employers are variously charged with the task of understanding and utilising earth resources to the benefit of society. It follows therefore, that undergraduate education and post-graduate specialization should be directed towards meeting the needs of employer groups in the geoscientific and geotechnical fields. In the past the training of most Australian geologists has emphasised classical science. This type of training remains of primary importance in the early undergraduate years but there is a need for modern educators to recognise the increased desirability for the inclusion of geotechnical subjects in the curriculum. Modern geo-education should address four main sectors when deciding curricula:

Jan 1, 1986

The purpose of this paper is to provide some practical commercial advice in relation to issues of access and trespass during exploration. It is not my intention to provide a detailed analysis of the applicable law because this is not the appropriate forum for latin maxims and turgid case studies. Instead I will explain the issues in sufficient detail to enable those who are not familiar,with the legal concepts to understand their obligations and responsibilities in relation to exploration activities. Take as an example a situation where a company (for the sake of attempted light relief, called Rogue Mining) holds an exploration tenement adjacent to one held by Lamb Exploration. In conducting aerial exploration activities over its own tenement Rogue overflies the tenement held by Lamb, doesn't turn off its equipment and accidentally collects data in respect of the adjacent land. In analysing that data it becomes apparent to Rogue that there is a substantial anomaly on the adjacent land of which Lamb is apparently unaware. Rogue subsequently negotiates to purchase an interest in Lamb's tenement.

Jan 1, 1995

The influence of pulp potential on the flotation behaviour of sulphide minerals in laboratory batch flotation tests is discussed in terms of self-induced flota- tion, collector-induced flotation, and depression.' Assuming that the pulp poten- tial is controlled by the same factors that determine the genuine redox poten- tial, an attempt is made to interpret the experimental results in terms of potential-dependent reactions based on bulk thermodynamic data. Self-induced flotation is displayed by many sulphides in moderately oxidizing solutions but not in reducing solutions. The available evidence suggests that the hydrophobic entity could be sulphur produced by superficial oxidation of the mineral but this has not been established beyond dispute. In general, flotation is observed near the potentials at which sul- phur would be expected to form and the minerals which produce sulphur seem to float the most strongly. Collector-induced flotation is most conveniently studied on minerals which have only slight self-induced floatab- ility. The mineral-collector interaction is potential-dependent hence flotation is generally only observed in limited ranges of potentials. While the general form of the floatability-potential relationship is similar to that predicted from thermody- namic data close correspondence between predicted and experimental results is not always observed.

Jan 1, 1984

The man in the street (and no doubt most members of the Institute) thinks of wire, if he gives it any thought at all, as a most commonplace commodity. It is an accepted necessity, and like most necessities is taken for granted, unless a shortage in one or other of its multitudinous forms or products causes inconvenience.For many years Australia has ·been a large consumer of wire, particularly for fencing. With the rapid development of secondary industry the demand has increased in both size and character until at the present time much of the wire produced in this country is used as raw material for subsequent manufacturing processes. The call has been of so varied a nature that the Newcastle Wire Mills now turn out a greater variety of wire types than any other single plant in the world.In this paper, the aim is to provide a picture of the manufacturing, properties, and uses of wire. No attempt is made to cover the subject in any detail, as the field is much too broad for anything other than general treatment. Many phases, particularly in regard to manufacturing processes, are, therefore, dealt with cursorily, but it is hoped that the paper will, without delving too deeply into the technical aspects of Wire production, give a general appreciation of:- (a) How steel wire is made. (b) The remarkable physical characteristics obtained by judicious combination of chemical composition, heat treatment, and subsequent cold work. (c) The uses of steel wire.HISTORY.Best known of the early references to wire is that appearing in Exodus, where mention is made of gold wire being used for the sacerdotal robes of Aaron. However, the period in question, about B.O. 1491, is comparatively modern history as far as wire is concerned, for specimens believed to have been made about B.O. 4600 have been found. It is fairly certain that the Egyptians produced iron wire in B.O. 4000. Of particular interest is the

Jan 1, 1947

By Davies L, Jeffreys J

The Broken Hill Proprietary Company Limited (BHP) has been successfully using mini computers in its open cut strip and pit coal planning for the past six years. A recent development within the computerised Seam deposit User oriented Mine Planning System (SUMPS) provides the facility for the generation, evaluation, and simulation of colliery workings.Existing computer programs for collieries were studied, but none met the requirements of BHP's underground mine planners.Consequently, it was decided to develop programs, based on those existing within BHP for open cut strip and open cut pit mine planning. The new planning facility was designed to enable any number of proposed colliery developments and operating plans to be evaluated against optimistic, most likely and pessimistic geological lease area interpretations.In mine planning, sensitivity studies should be conducted to determine the likely effects on production, development costs and colliery economics of changes in mine design and budgeted equipment productivity. By automating the manual calculations involved, the computer programs provide the ability to conduct numerous and extensive sensitivity studies. Hence an optimum mine design for budgeting purposes can be derived quickly with an improved degree of confidence in the long term viability of the proposed development.

Jan 1, 1982

By T Harrington, M Cox

There have been many changes in the Australian mining industry during the last 30 years. One of the most dramatic changes, from a geological perspective, is the reduction of in-house geological staffing and an ever increasing reliance on contract and consulting services. As a result, there has been a change in the way geological information is generated, managed and retained within the industry. This paper describes the changes that have taken place in the industry, provides two case studies of how companies manage their geological Intellectual Property and reviews some of the issues associated with management of in-house and outsourced geology services.

Jan 1, 2009

Technological advances evolve in different ways; many are the result of years of application of scientific method. i.e. Observation Deduction Hypothesis Proof In the mining industry, better explosives, drill bits or reagents are likely to evolve in this way. The scientific method is suited to the application of conventional management structures. Other advances are simply the result of a "brainstorm", or building a better mousetrap. Such inspiration probably resulted in "Split Set" rock bolts, or the first use of a vacuum cleaner principle for shaft mucking. Individual consultants can apply lateral thinking to generate such inspiration. In gathering material for the presentation of this paper, I sent a.letter to all members of the Mineral Industry Consultants Association asking them to nominate problems in the industry requiring investigation. The answers have been divided into two classifications - contract research underway and identified problems requiring solutions.

Jan 1, 1986

To obtain the best economic results in treating the comparatively high-grade ore of the Kalgurli Mine a good roast is essential, and the effort of this paper will be to briefly describe the plant and the conditions prevailing in roasting, which, on an output of about 360 tons daily, subsequently enable an average extraction of slightly over 94% of the gold to be maintained.The percentage of sulphur in the ore varies between 2'5 and 3'5, the lower figure existing when treating oxidized ore. The average gold value is 13 dwt; this occurs chiefly as sylvanite, containing .a lower percentage of silver than is usually present in that mineral. One ore body in the mine contains hessite (Ag2Te) in considerable quantity, associated with gold telluride, and when ore from this stope is being treated the silver contents rise to as high as 20 dwt, but the usual amount is about 9 dwt. per ton, of which only a small proportion is extracted. Other metallic minerals, in addition to pyrite, occurring more or less commonly, are arsenopyrite, magnetite, chalcopyrite, and the tellurides calaverite (AuTez)and coloradoite HgzTe3). A small proportion only of the value occurs as free gold.

Jan 1, 1911

This paper discusses the social and economic impact of mining, and in particular goldmining, on New Zealand. The range of topics covered and their complexity has confined us in this paper to highlighting the main points of concern û a detailed report is under preparation. A major problem in undertaking this study was the lack of hard data on important environmental, economic and social issues and if there is to be effective planning in the area of natural resource use this situation must be rectified. The following conclusions were drawn: Goldmining was very important in shaping New Zealand's early social and economic development, providing wealth, employment and impetus for social change.Foreign investment and technology has been an essential element in New ZealandÆs economic development.Mining is a small industry at present by this must not be allowed to obscure its potential to broaden New Zealand's economic base and provide foreign exchange.With modern methods, development of mineral resources and environmental protection are not incompatible but certain unique and irreplaceable areas must be preserved.There are problems in evaluating mining and other projects because different groups hold different values, and arguments often hinge on the valuation of costs and benefits rather than the technical aspects of the analysis.Mineral exploration is a high risk business and the potential returns must be sufficient to attract capital if New Zealand's mineral resources are to be developed.A resurgence of goldmining will clearly have obvious benefits for Waihi but the local community must plan carefully for their future. New Zealand will also gain valuable foreign exchange required for higher levels of economic activity.

Jan 1, 1981

By Lott JB, Scuffham JB

Until very recently the application of solvent extraction to. the recovery of metals has been considered only for ithose operations where no other process was available. In general, .these operations, have involved metals such as 'f uranium or the rare earths, where the value of metal recovered has been very high. As a result, the tendency has been to consider solvent extraction as a very specialised, high cost technique with minimal application in the base metal industry. Since the mid-1960's this attitude has had to be changed drastically with the development of solvents specifically designed for the selective extraction of individual metals such.ascopper. The result is that solvent extraction must now be regarded as a proven hydrometallurgical technique for the recovery of base metals, and in particular copper. The first significant event in the application of solvent extraction to base metals was the production by General M. Inc. of a compound, designated LIX-63 (R)(1), which was a specific extractant for copper from ammoniacal sns. This did not find a wide application, however, because copper solutions with a pH in the applicable range we more readily treated by conventional techniques.

Jan 1, 1970

A universal grinding circuit model suitable for an arbitrary structure of flowsheet has been suggested. In this model classifiers and mills are described in a most general form. What puts the model in a class by itself is the automatic mass balancing in all streams of the circuit. In order to provide this a special classifier model is adopted. A previously published continuous steady state process model is used as a grinding model. Non-linearity of classifier model leads to a resultant circuit model which is equivalent to a non-linear integral equation. It complicates somewhat calculation algorithm in comparison to that of linear model, but provides a physically meaningful solution.

Jan 1, 1993