Search Documents

This paper describes some of the challenges and opportunities of contract mining overseas, based on the experiences of Byrnecut Mining Pty Ltd over recent years. It seeks to highlight the advantages Australian miners have compared to competitors around the world, and the opportunities that arise from that. A number of pitfalls and how to avoid them are also discussed.

Jan 1, 2002

Regional problems, such as political risk and debt reschedulings, in Pacific Rim nations coupled with the price volatility of gold mean that multi-faceted financing packages are needed to offset the many risks inherent in a new gold mine development. The cross-border risks of getting money back out of a producing mine may require the involvement of export credit agencies, multilateral government banks, or political risk insurance. Variations on forward gold sales, gold loans, or offset structures can also enhance the flexibility and safety for the providers of both the debt and equity. The region will become as large a gold producer as South Africa by 1990. The large dollar amounts for both investment and revenues realised are of great significance to the economies of many of the Pacific Rim countries especially as a means to increase foreign exchange earnings.

Jan 1, 1987

Jan 1, 2004

The results from three quick methods for the determination of W03 in scheelite ore samples, mill products and concentrates were compared with gravimetric results and tested with standard samples to establish which was the most reliable. Summaries of the methods, two X-Ray fluorescence and one colorimetric, are given. The best method was X-Ray fluorescence, with samples cast as glass discs.

Jan 1, 1988

IntroductionHistory of MineTopographyGeology of AreaGeneral DescriptionIgneous Rock TypesGranodioriteQuartz monzoniteApliteGranite porphyryMetasomatic ActionAlteration of monzonite/Alteration of apliteGeology of Ore BodyNature of OreZones of MetasomatismAssociated Fracture PlanesDistribution of Copper MineralisationNature of Copper VeinsQuartz-chalcopyrite veinsQuartz-calcite-chalcopyrite veinsEuhedral quartz veins/Non-euhedral quartz veinsStructures Accompanying Ore BodyApliteIntersecting lines of metasomatised monzoniteMetasomatised aplite

Jan 1, 1949

Diagnostic Monitoring of Concentrator Circuits with Random Forest Models

Sep 13, 2010

Until 1937, the mining of ore was carried out by conventional methods, using pneumatic drills and standard drill steel. The adoption of the diamond drill, formerly used for exploration work, for blast hole drilling in stopes, was first developed by Noranda Mines Limited, Noranda, Quebec, although it had been used previously in Northern Ontario and Western United States, to remove weak pillars and ore remnants left by conventional methods. Previous to the adoption of the diamond drill method at Noranda, a sub-level benching system of stoping was used. Sub-levels were driven at 35 ft. intervals and the benches drilled off by pneumatic drills using sectional steel. Results were very satisfactory, in sulphide ore, where the drilling was comparatively easy, but in the harder rhyolitestopes the footage drilled per machine-shift was only half of that obtained in the sulphide stopes, and owing to the high gauge loss, there was often difficulty in drilling holes to the required depth. This led to trials with the diamond drill for this type of work. While the cost per foot was more than with sectional steel, an appreciable saving in development work could be made by increasing the sublevel interval from 35 ft. to 60 ft., and stope widths from 60 to 100 ft. This saving, together with the increase in blasting efficiency, resulted in a substantial reduction in overall costs.CONDITIONS FOR SUCCESSFUL APPLICATIONWhile long diamond drill blast-hole mining has widespread application, there are certain conditions which appear to be desirable, if not absolutely necessary, for its successful use.

Jan 1, 1946

By Jin C, Shuyi L, Yuanbiao Z

This paper describes the structure, performance, principle and effectiveness of a new laboratory type of composed-forces field separator utilising the composition of the magnetic force, vibrating force, pulsating force, gravity and fluid-viscous force etc to separate fine feebly magnetic valuable minerals. Compared with the pulsating high gradient magnetic separator, this separator possesses unique advantages of higher enrichment ratio and higher recovery of the magnetic component.

Jan 1, 1993

By J Szymanski, S Planeta

Extensive rockfill cylinder testing was performed to determine the effect that aggregate size, aggregate moisture, Portland cement, fly ash and cement dispersant addition has on compressive strength of a cemented backfill. In this paper ætwo-level factorialÆ and æcentral compositeÆ designs were used to determine the single and interaction effects that each factor have on the overall strength. The results from the designwork indicated that the per cent of aggregate fines had the greatest influence on the compressive strength of the rockfill cylinders. From the factorial design results, a compressive strength estimation equation was derived, which enables the strength to be estimated, given varying input values.

Jan 1, 1998

A review of the motivation of personnel in the open cut mining industry. The effect of social, geographic, environ- mental, organisational, union and other factors on employees' motivation as assessed from job experience and from an attitude survey. An appraisal of where we should be heading and what influence management can have on the motivation of employees.

Jan 1, 1980

Haematite Recovery from a Tailings Stream Laboratory and pilot scale testing were carried out in 1999 on a tailing sample from a North American iron ore plant using gravity, magnetic and flotation techniques. The ore contained 16 per cent iron mainly in the fine (-38 ¦m) size fraction. Two methods of evaluating the separation efficiency were used; Selectivity Index and Z factor analysis. Tabling and magnetic separation produced poor results, with flotation testing showing some promise, generating concentrates assaying more than 40 per cent Fe. High grade concentrates containing more than 67 per cent Fe were generated using the Kelsey Centrifugal Jig, and it was recommended that this technique be pursued at a larger scale to verify the results obtained.

Sep 13, 2010

By S MacKinnon, J Kok

Potential areas for improvement in flotation performance were identified during JKTech model development surveys in October 2003. Subsequent implementation of the JKTech recommendations in consultation with flotation cell manufacturer Outokumpu have resulted in gold flotation recovery increases of more than four per cent over a two-year period. One of these recommendations was the installation of High Shear Stators in the Cleaner and Recleaner flotation cells. The High Shear Stator installation project was justified based on simulations completed using JKSimFloat. Bubble size measurements completed before and after installation of High Shear Stators showed a reduction in mean bubble size of approximately 50 per cent in the Cleaner cells. Both Cleaner and Recleaner banks showed a significant narrowing of the bubble size distributions following the installation. Plant gold recovery increase resulting from the installation of High Shear Stators was 1.1 per cent, with a 1.9 per cent increase in flotation gold recovery and 5.4 per cent increase in flotation sulfur recovery. Based on the 1.1 per cent recovery increase and total project cost of less than $200 000, the High Shear Stator Project NPV was $8 200 000 with a 0.25 year payback period.

Jan 1, 2006

The successful operation of diesel equipment underground does not entirely depend on selection of robust, reliable, easily maintained machines. Results are also heavily influenced by the following factors: Design and condition of the operating area. Skill of operators. Correct maintenance facilities. Experience, skill and initiative of maintenance personnel. If the mine layout does not allow access to a central workshop area, the effect of any shortcomings will be magnified. The best results will only be obtained by close co-operation between mining and maintenance departments right from the initial planning stages.

Jan 1, 1977

By Quinn P, Robertson G, Agar GE

The replacement of diphenylguanidine (DPG) for separating INCO Bessemer matte with a water soluble collector requires a frother since most collectors do not have frothing properties. The objective of this study was to identify a non persistent frother which produced a deep froth and collapsed rapidly, while maintaining acceptable metallurgical separation. Incremental rougher flotation tests failed to differentiate any metallurgical benefit through the use of a specific frother, so other tests were employed to identify the candidate frother. The equilibrium froth height and rate of froth collapse (froth stability) of several commercial frothers were evaluated as a function of frother concentration using a 'frothmeter' apparatus. Frothers evaluated were methyl isobutyl carbinol (MIBC), Pine Oil, triethoxy butane, Dowfroth SA1263, Dowfroth 250C, Dowfroth 200 and Allied Colloids CRNI-1002. Dowfroth SA1263 produced the largest froth height, and TEB had the greatest rate of froth collapse. Frothers with properties similar to Dowfroth SA1263 and Dowfroth 250 were rejected due to their persistent froths. TEB was rejected because it has a low flash point and Pine Oil could be a nuisance to add to a flotation column. Therefore, the preferred frothers were declared to be Dowfroth 200 or Allied Colloids CRNl-1002.

Jan 1, 1993

A considerable amount of psychological research has been conducted on human behaviour and its relationship to accidents. However, the research covers very wide fields and the findings drawn are so varied that at first sight they are confusing and there does not appear to be any major useful lead. I propose a discussion of a number of research findings to illustrate the variety and complexity of the human behaviour factors involved in considering safety. Such discuss- ion might point to some conclusions which could lead to an action programme to improve safety records.

Jan 1, 1975

Good morning ladies and gentlemen. It gives me great pleasure to talk to you today about a pet subject of mine, on when to mill and when to leach gold ores. According to Gold Fields Mineral Services of London, gold production in the United States in 1989 amounted to about 8.5 million ounces (259t), an increase of 29 per cent over 1988 and 67 per cent over 1987. The U. S. Bureau of Mines reports that from the major producing states of Nevada, California, Montana, and Alaska, some3.2million ounces of the 1989 production were produced from milling gold ores and 2.3 million ounces from heap or dump leaching. Ap- proximately 45 million tons of ore were milled and 140 million tons of ore were heap or dump leached.

Jan 1, 1991

The commercial outcomes from new mining projects or brownfields expansions often fall short of feasibility study forecasts because of technical under-performance. This paper: reviews past feasibility study performance; identifies the key drivers of underperformance; and proposes actions that can be taken to manage the risk of underperformance. There have been a number of published reviews of feasibility study performance since the 1970s. The results of these studies are summarised together with recent unpublished data. Key drivers of underperformance include inadequate metallurgical testing, simultaneously pushing a number of project parameters beyond comfortable limits and a failure to recognise the linkage between mining rate and head grade. Actions can be taken during the data acquisition phase and during the feasibility study to manage project technical risks. These generally require a more flexible approach to study management than can be achieved under a ælump sumÆ contract.

Jan 1, 2003

In the years prior to the outbreak of war in 1939 Australia's production of copper had declined from a peak of about 80,000 tons in 1911-1915 to approximately 25,000 tons in 1939. This production met the need of the slowly growing national requirement and gave an excess for export. However, with the intensification of the war effort in 1942 due to the imminence of a Japanese invasion of this country, or at least a blockade of the sea lanes, it became necessary to expand production of armaments, and consequently the demand for copper increased beyond the capacity of the industry. Importation of copper to Australia during the period 1940-1944 was 131,000 tons.When exploration of the Mount Isa orebody was first being carried out in 1928, No. ID diamond drill disclosed the presence of some copper ore lying outside the limits of the Black Star orebody2, but it was not until 1941-1942 that the development of No. 7 level in the Black Star orebody enabled the existence of a lode of copper ore of economic grade to be established. At the request of the Commonwealth Government of the day a programme of development for copper production was undertaken whilst lead smelting was continued as before the war.A series of flotation tests on up to 1,500 tons of ore at a time, was undertaken and the concentrate so obtained was stockpiled. These tests were conducted, using one section of the lead mill, and demonstrated that a concentrate grade of 22-23% Cu with a recovery of 80-85% might be expected.These recovery figures were afterwards much improved, and 93-95%was obtained before the close of smelting in 1946.

Jan 1, 1953

By Price B. D, Staunton W. P

The Mineral Science Laboratory of the Government Chemical Laboratories has recently investigated various procedures for the analysis of the platinum group metals (PGMs). This investigation covered a number of methods for the extraction and preconcentration'of the PGMs from a wide range of geological materials. The nickel sulphide extraction technique proved to be overall the most applicable procedure. Flame atomic absorption spectroscopy (FAAS), electrothermal atomisation atomic absorption spectroscopy (ETA-AAS), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS) were examined for their suitability in analysing platinum group metals in solution. ETA-AAS and ICP-MS proved to be the instruments of choice due to their low detection limits.

Jan 1, 1987

A Modelling Approach Using a Back-Calculated Induction Time to Predict Recoveries in Flotation

Sep 13, 2010