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By G B. Siddall

The paper examines the current state of equipment and circuit design, with reference to Australian practice. Following a review of the changes in milling applications over the last 15 years, developments in mill design are examined. Current issues include trunnion versus shell support; drive type and economic analysis for comparison of the various systems; the efficiency of the mill discharge system for slurry and pebble removal, and lining configuration. Peripheral problem areas such as pebble crushing and classification are briefly examined. Circuit design issues are reviewed. The decision to modify the traditional primary crushed feed is examined with reference to recent and proposed installations. A retrospective look at fully autogenous installations and their successes is presented, and current views on increasing throughput are assessed. Finally, future developments are anticipated in mill design and control, and competing processes are identified.

Jan 1, 2002

By G A. Streltsova

In the paper the main concept of qualitative simulation is determined when computer-aided designing and forecasting of designs of robotised continuous-flow working face complexes for underground mining of hard ores. The parametric model æunderground ore mineÆ and its components û composite models are considered. Frame description of structure of working face complex and methods of organising of rule-oriented representation of knowledge when itÆs operating are given. The architecture of the developed prototype of expert system æworking face complexÆ and construction of a knowledge base for it are described when solving problems of multi-criteria optimisation of computational parameters of the working face complex under conditions of uncertainty. The guidelines for further development of knowledge base and expert system are given.

Jan 1, 2003

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

Within the Ross River Basin, the following types of water were collected and analysed; 19 streams, 24 wells and bores together with 19 samples from the Ross River Dam. The waters were found to contain up to 269 ppm of silica and, although they meet the requirements for industry in all other respects, this extremely high figure means that two basic guidelines should be followed. All steam generation units, except those less than 150 psi should employ hot lime zeolite softening, demineralization or evaporation to remove silica. Cooling systems should only operate on a once through basis.

Jan 1, 1978

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

Taxes have an impact on mineral resource availability in several ways. There is the obvious effect on the grades needed for mineral deposits to become economic orebodies. There are also indirect effects which can have equally significant impacts. The paper examines the appropriateness of different types of taxes in the mining industry. The effects of discriminatory taxes such as price-based royalties are described. There is a discussion on the feasibility of introducing a single resources tax to replace completely the various forms of taxes presently applied to the industry. The subtle impacts of taxes are described in a section covering the way in which apprehension over future possible changes to both the level and diversity of taxes is reflected in industry confidence. It is concluded that taxation can significantly limit the economic availability of mineral resources.

Jan 1, 1978

This paper details the approach adopted to develop an integrated asset management system for a GreenfieldÆs Metallurgical Plant during a recently completed feasibility study. The proposed asset management system deals with general aspects related to metallurgical operations and includes the following:plant operation and control, human resources, security systems, stores, and maintenance management. The paper deals with the establishment of requirements for the asset management system, the interfaces required, available systems in place and cost estimations for implementation. Every effort was made to integrate the system into existing corporate installations to create an integrated and effective management tool from both a plant operation and support perspective.

Jan 1, 2002

The mineralogy of the crocidolite (blue asbestos) veins at Wittenoom Gorge was examined to determine the cause of failure to recover soma of the fibre by the ore-dressing methods currently being practised. As a, result of this yamina.tion, several fo.Ctors pertinent to the problem were found to be a function of the pa.ragenosis of the veins. The occurrenceof magnetite from tho'cap rock within the veins was thought to be preventing fiborisation during troo.tment. Several petrologic features are described and their relation to the ore genesis is discussed, Comparison with the crocidolite deposits of the Union of South Africa is also considered.

Jan 1, 1963

By X B. Sun

Mining work is a high-risk operatation under a special environment. It is affected by space, lighting, noise, vibration, dust, air pollution, etc as well as coal seam conditions, complicated geology construction, combustion of coal, gas, coal dust, etc. Factors which affects safety production are numerous, eg natural conditions, technical equipment level, producersÆ and managersÆ qualities. It is a complex system engineering to ensure mining safety and high efficiency. Among the ideology, methods and measures of safety management are the most important factors besides safety technology. Mine productive environment is a main problem that affects minerÆs work as far as safety and health are concerned. Combining ChinaÆs mine productive environment situation and using human ergonomics theory, this paper explores a series of measures and suggestions as to how to reinforce safety management, how to build up the safety management ideology, how to improve the mine production environment, how to decrease coal mine accidents, and how to ensure mining safety and high efficiency.

Jan 1, 2003

This work provides a comparison between the most commonly used classification equipment in the treatment of minerals - hydrocyclones and spiral classifiers - considering their applications and costs. Although in use for decades in the mining industry, spiral classifiers have lost a lot of their importance due to the development of cyclones. This trend, however, is now being reversed, and in the last few years there has been an increasing interest in spiral classifiers, in view of their advantages over cyclones, such as: ò possibility of obtaining more thickened solids; ò less by-pass; ò great durability; ò lower operating cost. This work approaches the different aspects related to the installation, operation and costs of maintenance of these machines, giving a critical comparison of the involved costs.

Jan 1, 1993

Some fundamental aspects of recent single-particle fracture studies are reviewed. Findings from this research shed new light on the utilisation of energy during comminution operations and provide useful pointers to new research directions that could lead to significantly better comminution machines. Two methods for quantitatively predicting mineral liberation during comminution are reviewed. These methods have been developed into useful practical procedures, but they are almost unknown in the mineral processing community. Their use should promote the consideration of mineral liberation as an important variable to be considered during the design and operating control of comminution circuits.

Jan 1, 1993

The word `environment' may have many different meanings but, for the purposes of this paper, I have assumed the definition included in the Environmental Protection Act 1986 (Western Australia). This Act defines `environment' as `... living things, their physical, biological and social surroundings, and interactions between all of these'. The Act further defines the `social surroundings of man' as `... his aesthetic, cultural, economic and social surroundings to the extent that those surroundings directly affect or are affected by his physical or biological surroundings'. This gives a very broad meaning to the idea of environment and environmental issues, and it is therefore understandable that the influence that environmental issues have on mining activity can vary so much from state to state, and even within states, and why the degree of influence can change so much with time.

Jan 1, 1990

In recent decades the awareness of environmental issues by the general public has developed at an accelerat- ing rate. This is the result of a number of factors including more scientific knowledge of environments and of the impacts of modern society upon them, higher levels of education, the opportunity for people to travel more, and the success of the various communication media in bringing in- formation to the communities of the world about such environmental crises or threats as the smogs of Los Angeles and London, the Torrey Canyon and Santa Barbara oilspills, Minamata disease in Japan, the spread of the Crown of Thorns starfish, the disposal of toxic industrial wastes into the Upper Rhine, the discovery of high mercury and zinc contents in marine foods in southern Australian waters, and the proposal to mine limestone at Precipitous Bluff in Tasmania.

Jan 1, 1975

The bureaucracy in Victoria has worked against exploration and mining development. There is no doubt that the new Mineral Resources development Act has simplified matters on the mining side of the system. However, WMC's Bendigo and Deep Lead experiences demonstrate that other parts of the bureaucracy can cause serious delays. The mining industry continues to view the approval process causal of excessive costs and delays compared with other States (and countries) and prohibitive to investment in Victoria.

Jan 1, 1992

Dynamic hydrothermal modeling is a tool that can aid in studying problems associated with hydrothermal ore deposits and can help increase our understanding of the spatial distribution of ore within hydrothermal systems. Models are constructed by a sequence of steps involving development of a conceptual model, followed by its mathematical description in terms of governing equation with accompanying initial and boundary conditions. This equation is then solved either analytically or numerically. The four model types ò that fully describe a hydrothermal 'system are those for fluid flow, heat and ore solute transport, and deformation. At Renison, models have been used to help understand two major exploration problems. These are the controls on ore localisation in dolomite horizons and feeder faults respectively. The types of models used ò have simulated the distribution of all mineral zones, pyrrhotite, and temperature in the dolomites. This has allowed evaluation of the effects on ore localisation by physical and chemical heterogeneities within the dolomite host rocks, and allowed estimation of potential controls in different physical and chemical environments.

Jan 1, 1987

By L Ryan, S Halley

The use of a field spectrometer to systematically analyse drill samples from over 200 holes around the Permian-Carboniferous Ravenswood gold deposits in north-east Queensland has successfully identified both small and deposit-scale changes in the alteration mineral chemistry. Changes in chlorite composition within the tonalite host rocks are evident at the district scale, with Fe-rich chlorites seemingly more common in the vicinity of the deposits. Significant variations in white mica chemistry also occur, but mostly on the vein selvage scale, with no clear distinction between near-mine and distal compositions. The results indicate that chlorite compositional maps produced from regional field or airborne spectrometer data could potentially be used as a vector to ore in exploring for similar deposits in the area. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

Whether you are an employee, contractor or consultant working in the mineral industry, there are pressures to deliver the best possible performance. Technical professionals are usually driven by an internal desire to perform to a high standard because of personal pride in their profession, but there are an increasing number of external requirements to demonstrate that the actions taken were based upon reasonable grounds and that the work conformed to current best practice. People expect these best practice procedures to be followed and governments are now requiring those tendering for contracts to be registered in some way and to be participants in quality assurance schemes. One is not immune to these pressures just because you are working in a less legislatively sophisticated developing country in the circum-Pacific rim (Pacrim) region.

Jan 1, 1995

The global recession of the 1980s drove commodity prices down and intensified cost competition. The 1990s saw a restructuring of the mining industry with the survivors adopting new technology, significantly increasing workplace productivity and reducing capital and operating costs. Major changes in mining industry business strategies evolved in the late-1980s including the development of miner - supplier - manufacturer - partnerships, cultural changes in work practices and common goals between the partners to reduce the cost of production. These industry trends are putting new demands on mining machine manufacturers and dealers both on the `hard' side of the machine business, such as research and product development programs, and on the `soft' side in terms of business processes, use of human resources and communication. The paper describes several mining industry trends as identified by a large supplier to the industry, and discusses the impact they are having, and will have, on mining machine development and the provision of product support services to the industry.

Jan 1, 1995

The global economic, political, sociological, and technical environment has become extremely volatile and unpredictable. Price and demand patterns for fuel and non-fuel minerals have become highly variable. Increasingly militant environmental movements now have a material effect on the price, cost and availability of energy sources and indirectly also on non-fuel minerals.The pace of political change in the U.S.S.R., Eastern Europe, and China has accelerated. Western Europe, Japan, and the U.S. are reacting to these changes with varying degrees of confidence or timidity.Technical and economic developments continue to have a substantial effect on the fortunes of the mineral industries. However, they are increasingly influenced by social and political factors. Supply, demand, and trade patterns in the Pacific Rim Region will continue to be influenced by developments in other regions, such as southern Africa

Jan 1, 1990

By Gillies A. D S

Technology transfer is a vital requirement for increasing national capability of coal mine production in Indonesia. The term can cover the introduction of new equipment, facilities and processes and approaches to training and education. Constraints on technology transfer within the Indonesian coal mining industry are reviewed. The contributions that foreign companies working within the industry can make are discussed. It is concluded that the development of major Indonesian coal mines needs input of advanced foreign technology. The foreign mining companies are investing significant capital in operations and are permitted to import outside expertise due to some lack of national skills. Expatriate employees are expensive and have a direct effect on profitability. The success of any replacement program of foreign employees is dependent on technology transfer. There are statutory Indonesian Government directions to reduce dependency on foreign expertise over time.

Jan 1, 1995