Search Documents

The law relating to the Treaty of Waitangi is developing rapidly at present. A number of separate, but related, developments can be identified.

Jan 1, 1988

Until the early 1960s the world aluminium industry was dominated by six principle pro- ducers with integrated activities from bauxite mining to aluminium production. The growth in consumption of aluminium since that time and the emergence of additional producers has broadened the market for bauxite. In addition the increase in the optimum size of alumina refin- eries has influenced competing metal producers to unite in large joint ventures to minimize alumina costs. From these bases the paper examines present and likely future markets for Australian bauxite; differing marketing phil- osophies for serving those markets; factors influencing successful marketing; and the sources and relative strength of competition which Australia faces.

Jan 1, 1974

By Davidson JR, Napier-Munn TJ, Kojovic T

A research program was conducted to determine the relationship between operating conditions and medium losses in Mt Newman Mining's Beneficiation Plant. It was found that major medium losses were adherence losses and losses fran the overflow from the water recovery cyclones. Operating density and medium blend were found to have a significant effect on the medium consumption. Viscosity was thought to be the underlying factor. This viscosity problem was overcame by adding dilution water to the cyclone spigot discharge to reduce viscosity. The result was a reduction in medium consumption of 25 percent under normal operating conditions. Keywords:- Heavy Medium, Viscosity, Medium Carposition

Jan 1, 1987

An outline of the circumstances giving rise to the current Commonwealth-States con- flict in relation to offshore mineral explor- ation and production is set out, together with an analysis of the Seas and Submerged Lands Act 1973. The bases of the claims by the Commonwealth and the States in this regard are discussed with relation to the territorial sea and the continental shelf.

Jan 1, 1974

Improvements in mechanisation should not be considered independently of safety and of environmental hazards. The need to keep gas contents within statutory limits may make the time needed to partially drain a gassy seam the effective control on face development times. Dust levels may provide an effective control on coal extraction rates on any one face. The combination of gas and dust on high output longwall faces may make it necessary for each one to be treated as a separate mine in terms of ventilation, and the faceworkers may need special protection. Mechanisation and safety can be mutually beneficial when mechanisation combined with systematic safety assessment reduces accidents, and when a thorough study of how to reduce accidents and health risks indicates the best method to improve mechanisation.

Jan 1, 1988

The mineral resources of Hamersley Iron are structurally complex with fluctuations in mineral chemistry. Besides orebody charact- eristics, mineral recovery is also affected by stringent product quality demands from the competititve steel industry. Under such conditions, a geological ore reserve estimate has little meaning because it is unqualified and presupposes the defini- tion of ore. A system was developed in Hamersley - the Mine Planning Technique - to optimise recovery from available resources. This incremental planning method reduces a geological reserve statement into a simple, logical sequence of events. While there are limitations in the method used, the benefits are enormous. Among its' numerous applications, the schedule - the end product of the technique - plays an important role at Management level in decision making and policy formulation on all aspects of resource exploitation.

Jan 1, 1979

The development of computers is examined in the context of the mining industry. The risk element is given as a reason for the slow introduction of the computer into mining. Dealing with mining's uncertainty is seen as a major role for computers. The use of computers is traced from early accounting applications to current involvement with all aspects of mining. The problems associated with increasing use of computers and their impact on management is discussed in depth. Disenchantment of management is thought to arise from unfulfilled expectations. Contributory causes are given as overselling of computers, reaction against change, speed and growth of computer technology. The solution is seen to lie in a more dominant role for user management in the development of computer systems and greater emphasis on education. The computer of the future will then become integral to the mining process as an extension of management's planning and control function.

Jan 1, 1974

The strategy of adjusting operating conditions to maintain optimum process performance as the feed quality varies - adaptive optimisation - is being investigated by computer simulation of chemical processes for the treatment of ores. Those ore-process systems that are most likely to yield substantial benefits from adaptive optimisation are being identified as a guide to the selection and development of systems for practical application. The generalised mathematical representation of the cost structure, ore quality variations, process kinetics, reactor characteristics and operating variables for ore-process systems is described. Results are summarised for temperature, reagent concentration or residence time as the manipulated variable. For almost all systems, adaptive optimisation was economically beneficial, although a few exceptions have been identified where there is a significant synergistic effect between poor-performance and good-performance materials in a blended feed. The sensitivity of the benefits of adaptive optimisation to a range of economic and technical factors is summarised.

Jan 1, 1985

Conceptually coal reserve assessment is simple but in practice it presents many problems. These arise from the origin and geological history of coal seams and from the diverse nature of the coal itself. The suitability of a coal for a particular use depends upon its type and so sheer quantity of reserves does not guarantee the adequacy of coal reserves for all requirements. Codes have been formulated to counteract the effects of subjectivity in reserve assessment. The code for calculating and reporting coal reserves published by the Standing Committee on Coalfield Geology of New South Wales has wide acceptance but the Committee itself recognises that it has shortcomings. Currently the Committee is engaged on the commendable but difficult endeavour of formulating a code that will meet the needs of scientific rigour and professional and commercial ethics and that will allow the specification of an assessment method without constraining it. It is generally agreed in the coal industry that the assessment of coal reserves can not conveniently be incorporated into codes formulated for other resources.

Jan 1, 1979

By Paine G

Kidston Gold Mines commenced mining in 1984 and currently mine approximately 10 million tonnes per annum of ore and waste using a conventional truck and shovel open pit method. The overall mine grade is a low 1.82 grams per tonne.The mineralisation is generally uniform within the ore zones and mining boundaries are staked out from blasthole assays according to pre-determined cut-off grades. Buffer blasting is necessary to minimise post-blast lateral movement of in-situ grade for digging control.The characteristics of the rock currently mined vary widely from soft oxidised to hard unweathered rocks. Blasting problems have been experienced during the initial mining phase in these harder rocks.

Jan 1, 1986

Most mineral products exported from Australia to Japan, with the notable exception of coal, are purchased with weight and quality determined on discharge. Sampling of imported minerals for purpose of payment is done at facilities owned and operated by the purchaser. The selling shipper is represented at the weighing, sampling and testing by an independent inspection group who supervises the whole procedure. Sampling and testing are done within the provisions of the contract between the two parties, and normally in accordance with the relevant Japanese Industrial Standards (JIS). These JIS specify such things as the number and mass of increments to be taken; the practice of taking these increments; the method of determination of moisture, size distribution and quality. The JIS concerned with sampling however, are meant to be basic guides rather than rigid rules. Hence sampling and testing practice varies from plant to plant. In general Japanese sampling facilities and methods are elaborate and efficient. Opportunity is given for the discussion of varying technical viewpoints between consumer and shipper. However the resolution of differences and the implementation of changes normally takes a long time. Such discussions seem best reduced by prior contract agreement on reasonable specifications and detailed testing methods. The independent inspectors

Jan 1, 1976

By Leigh G, Gottleb G, Wilkie G

The estimation of particle liberation is important in the study of mineral concentration. With simple systems, where the densities of the components are low, the liberation can be studied directly by density fractionation. For most practical systems, and particularly for the dense, complex sulphides, the only method known is by measurement in polished section. There are two major difficulties with such measurements. Firstly, the measurements themselves are difficult and considerable care is needed before reproducible results can be achieved. Secondly, a well known stereological problem arises which gives the estimates an inherent bias. The paper discusses both aspects of the problem. The practical features of measurement are treated in detail and a method described which has been developed and proven to give reproducible estimates of the liberation in the section. This discussion relates to automated measurements by QEM*SEM and presents a way of estimating the confidence limits within which measurements lie. Comparisons are shown between measurements made by the traditional manual optical technique and automated equipment. Stereological reconstruction is also discussed briefly. Several methods have been presented in the literature but all are complex and none is yet widely accepted. Area measurements are less biased than linear estimates so a practical approach is to use area measurements in uncorrected form. The topic is still being actively researched so it is expected that one method will soon emerge as the standard technique.

Jan 1, 1993

By R Barrette, V Lawson

Over the last year at Clarabelle Mill, three circuit reconfigurations were implemented. One circuit reconfiguration, æA CleaningÆ, was initiated due to a furnace failure at the smelter complex, and two of the circuit reconfigurations, æincreased copper (Cu) separationÆ and the æInterim IsaMillÖ circuitÆ, were seen as opportunities to increase cash flow through the mill. A Cleaning and the Interim IsaMillÖ circuit took advantage of engineering design already completed for a major capital project. The engineering for each was modified, as needed, and construction of the required portions of the capital project was fast tracked. The increased Cu separation circuit change used existing test and plant equipment to increase the plant Cu concentrate production. Implementation of the projects required teams that included operations, maintenance, technical support, project management and capital project resources. This paper discusses the business reasons driving the changes and the forethought or synergies with other work, which made them a success, and what was learned through each project. CITATION:Taylor, A, Lawson, V and Barrette, R, 2012. Responding to the challenge - Necessity driving circuit change, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 247-254 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By B Sno, P A. Cockburn, R C. West, C U. Jones

Clyde Materials Handling (CMH) and WorleyParsons have developed a concept for a flash furnace feed system using the specialist pneumatic conveying equipment expertise of CMH and the flash furnace process experience of WorleyParsons. CMH has developed a proprietary volumetric feeder (called a Rotofeed), which is extremely accurate and overcomes many of the problems inherent with loss-in-weight screw feeders and drag chain conveyors, previously regarded as state-of-the-art. Initial indications are that the Clyde-WorleyParsons feed system could deliver the following benefits to flash furnace operation: accurate pulseless delivery of feed material to the head of the burner leading to improved combustion performance and process stability; highly accurate split to the individual quadrants of a conventional burner tube, or provision of a smooth hollow curtain to a burner without guide vanes; decreased pressure pulsation in the furnace due to improved combustion control and performance; and decreased temperature fluctuations in the furnace due to improved combustion characteristics and hence reductions in refractory thermal stress and wear.

Jan 1, 2005

By I Kolomaznik

Each technological process can be reduced on the transport networks, and namely on the parametric networks and the non-parametric ones. The parametric networks are created by the piping, electrical cables or channels. The non-parametric network is created by the ways, suspended grooves, trackages and also by the belt conveyors or other conveyors for continuous material transport. If we reduce the technological process on transport networks, then, by the creation of these networks models and their mutual interconnection we obtain the model of the whole technological process. The model can be understood as the universal one, without exaggeration, because it is valid for any technological process. However, for us the mining production process is important what represents the mining and transport of raw materials under the support of the ensuring system. In this contribution one of the first attempt is described, and namely how to connect the parametric network which has been already worked out very properly with the non-parametric network what is presented in this contribution by the transport line of belt conveyors.

Jan 1, 2003

The nickel refinery at Yabulu consumes an average of 118,000 kg/h of low pressure steam in stripping operations to-recover ammonia and carbon dioxide from product liquor and ore tailings streams. The steam used in the stripping operations is produced from the 25 MW power generation plant at the refinery. The back pressure on the non condensing steam turbines is maintained at 60 kPa.Studies have been carried out to determine the optimum amount of steam required to be generated for stripping operations. When steam production is increased, the product liquor flow from thewashing thickeners can be increased. This results in improved washing efficiency of the thickeners and therefore improves the plant nickel recovery. A computer thickener wash model was used to predict nickel recoveries at varying steam consumption rates.The studies have shown that in most plant situations, it is not economical to-generate more steam than that already available from existing power production.The studies also highlighted the necessity to use all steam generated from power production at all times to maintain maximum nickel recovery.

Jan 1, 1985

By Willis G. M

Preliminary experiments have shown that, when used in a fusedchloride electrolyte, titanium carbide anodes dissolve yielding lower titanium chlorides which nlay be electrolysed in situ to produce a cathode deposit of pure titanium metal. The anode residues are easily withdrawn from the cell. Further experiments have established the operating conditions for maximum efficiency in the process.The process is essentially two-stage, viz.: (1) titanium carbide production, (2) electrolysis producing metal. Power requirements appear to be moderate and this fact, combine·d with the simplicity of the process make it attractive as a possible method for the production of titanium.INTRODUCTIONDue to the high reactivity of titanium and its, affinity for oxygen and nitrogen, the extraction of this metal generally involves the use of halide. compounds as intermediates. For instance, magnesium reduction of titanium tetrachloride is the basis of the well established Kroll process and electrolysis of the lower chlorides in a molten salt bath has been proposed by Cordner and Worner (1951, p. 358) and others (Brenner and Senderoff, 1952, 223C; The TitaI Company (Inc.), 1952) as means of production of the metal. Thedifficulty of preparation of these compounds prompted a search for an alternative extraction process. The fact that aluminium, an equally reactive metal, has been prepared by electrolysis using aluminium alloy anodes suggested the possibility of a similar process for titanium production.The Titan Company (Inc.) (1952) has patented the use of crude titanium metal anode, but it was thought possible that a metallic compound, such as the carbide, could be used for this purpose. Although Lorenz and Kaufler (1909) suggested the use of carbide anodes for metal production, no...

Jan 1, 1956

By M Roberts

The aim of this paper is to evaluate the technical feasibility of application of the electric monorail as a haulage system in hard-rock underground mining in Australia, in comparison to conventional truck haulage systems. The elements of the system being investigated include mine design and layout, installation, loading and unloading subsystems, tramming speeds, cost and productivity, automation, ground support, safety and environmental factors. Electric monorail systems are potentially more cost-effective due to a range of factors: only the one system may be needed for the transportation of workers, material and rock; and excavations for monorail haulage can be smaller and mined at much steeper gradients than for truck haulage. The smaller excavation size also reduces the need for costly ground support and û in another important measure for the health and safety of mine workers, and for energy savings û it reduces ventilation requirements. Electric monorail haulage technology is being applied in hard rock mines in South Africa and considerable benefits have been realised by the industry in that country. In Australia, mine designs for metal mines generally remain based on truck haulage and/or shaft hoisting systems. There is a tendency to apply these haulage systems to every orebody. For the industry to achieve sustained growth against a backdrop of volatile diesel prices and environmental concerns, new generation underground haulage systems are required. The monorail haulage system offers opportunities in improving materials handling efficiencies in underground mining operations. This paper examines the application of monorail haulage in metalliferous underground mining, presents comparative data with track and trackless haulage systems and develops concepts for system application in combination with conveyor belt haulage and narrow vein mining situations.

Jan 1, 2005

By Misk A

Several logging methods are presently available to the oil industry for the evaluation of formation porosity: the Sonic and Neutron logs are already widely used, the Gamma-Ganmia log is being progressively introduced. The readings of these instruments are primarily a function of the rack-porosity, hence the general term of "porosity tools". Apart from porosity, however, other variables such as type of fluid in the pores, nature of matrix and degree of shaliness have an important influence.The response of each device is a different function of such parameters: therefore, a cci bination of porosity tools can lead to information on these variables in addition to the evaluation of effective porosity.For example, the presence of gas; rather than water or oil, in a formation which is not deeply invaded, will tend to give Neutron derived porosity values which are too 'low; on the other hand, the Sonic derived porosity: value will be too high in such- a case. For the same porosity, the Sonic gives a longer transit time in sandstone than limestone, whereas in the low porosity range, the Neutron will read more counts per second in a sandstone than in a limestone of the same porosity. The presence of shale also affects the readings of the various porosity tools in different ways so that the combination of two or more methods may lead, in some cases; to an evaluation of both the-effective porosity and the shale, content.In conclusion, it may be said that the various porosity tools pre-sently available, are, to a large extent, complementary, and that in many problems the use of two porosity tools, instead of one, is very likely to bring valuable additional information.

Jan 1, 1962

The process of refurbishment is not a precisely defined one. It is under- stood to mean an upgrading of a plant which is normally performed only once. The application of refurbishment in the field of materials hand- ling equipment poses particular problems because complex plants con- sist of individual components having quite different remaining service lives. For this reason, a systematic, proven procedure is proposed for the refurbishment of large materials handling equipment, designed to ensure economic implementation in accordance with the company goals. Rheinbraun2 has been using materials handling equipment since 1900, the largest units today being bucket-wheel excavators with a daily capacity of 240,000 bank cubic metres of overburden and a service weight of up to 13,500 t (metric tons). Since 1975, more than 50 large-scale refurbish- ment projects have been carried out in the company. In the process, refur- bishment has turned out to be the proven alternative to replacement of large materials handling equipment. Rheinbraun Engineering,3 a Rhein- braun subsidiary, carries out planning, consulting, and supervising work in the implementation of refurbishment projects in Germany and abroad. The most recent example is the refurbishment of Dredger 11 of the State Electricity Commission of Victoria in cooperation with Krupp-Australia, Melbourne.

Jan 1, 1989