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With the use of 36 rock drills of the jackhammer type at the West Lyell Open Cuts of the Mt Lyell Mining & Railway Co, it is of importance to determine the economic as well as the physical life of these machines. With this purpose in mind records have been kept of the footage bored and the cost of new parts placed in each machine, and the following procedure adopted.A graph is plotted for each machine showing the footage bored as a horizontal line and at each 5000 feet of boring the total cost of new parts is noted on this line (see Figure 1). Thus at a glance it is possible to see the amount of work done by each machine and the money spent on it in new parts. However, it is difficult to visualise from this graph the increase in the cost of new parts for each machine as its life advances. To obviate this clifficulty a curve is plotted with the cost of new parts as the vertical component and the distance bored as the horizontal component.As before the cost of new parts are taken at each 5000 feet bored (see Figure 2).

Jan 1, 1994

The maintenance system for underground mobile equipment at Cobar Mines Pty. Ltd. has been modified from that originally planned as a result of experience gained in operating the equipment.Downtime due to breakdowns has been reduced by improvement of vehicle servicing and overhaul procedures.Frequency of breakdowns can be reduced by training operating and maintenance personnel to a high standard, ensuring adequate numbers of tradesmen and supervisors, good maintenance facilities and communications, a well designed mine layout, and a comprehensive stock of spare parts.A maintenance and downtime summary is compiled for each four-week operating period and this is useful in highlighting particular problems where corrective action must be taken.

Jan 1, 1969

With the evolution rate of technologies, earthmoving equipment users are establishing vision statements for their operation out to and in some cases beyond 2000. Autonomous systems are receiving a lot of 'press' - and rightly so, as they hold a potential for achieving quantum leaps in productivity and cost gains. Caterpillar feels that it is important that the infrastructure of on-board systems are understood and can be utilised more in the near term to `grow' a user up to the stage of autonomous operation.

Jan 1, 1997

In an earlier paper(l) details of a laboratory method of extracting and separating tantalum and columbium oxides from tantalite have been given. In view of the fact that Australia may have need to be self sufficient in this field it was decided to erect a pilot plant for the production of tantalum oxide in the Metallurgy School, University of Melbourne. The plant was designed for treating about 40 lb. of ore in a batch over a period of two weeks, although; because of the sectionalized nature of the process, the capacity of the plant was 40 lb. ore per week.Australia is fortunate in possessing some very rich tantalite and columbite deposits, particularly in the Pilbara District in Western Australia. The ore used in this work was obtained from a small but high grade deposit near Greenbushes, Western Australia, and consisted of lumps, weighing up to 8 lb. each, of almost pure ferro-tantalite with occasional thin veins of the very' rare' mineral stibiotantalite.The main constituents were:

Jan 1, 1946

Although the 'exi'stence of bauxite in Australia has been known for many years it is only recently that exploitation has commenced.. of the two most' important` deposits, strangely at almost diagonally opposite tips of the continent. Recognition of the importance. of the bauxite in the South/West corner came about initially through the efforts of a well-known Australian mining company which,` with some outside financial help, tackled the early exploration with commendable foresight and courage.

Jan 1, 1964

The application and development of monitoring and control techniques of coal mines in China is mainly described in the paper.The techniques of mine control and monitoring system have been developed as an important means of production dispatch, command and management with ever-increasing coal production and gradual raising of the level of mechanization and centralization of continuous mining. The continuous stage monitoring and control system in China coal mines has been developed from the initial single fixed plant monitoring, and the technique of computers has also been applied in the system for productive and environmental monitoring, featuring a new type of mine control and monitoring equipment of China.

Jan 1, 1985

By S N CARRAS

Ore reserve estimation is a procedure involving data collection, data storage and judgement and assumptions about geology mining and metallurgy. Calculations are based on these assumptions and an economic analysis on projected cash flows is carried out. Ore reserve estimation must therefore be subjective and will always depend on the extent to which the assumptions used in arriving at the estimate are correct. This paper is an attempt to summarise the many aspects that can contribute to ore reserve problems and to offer some suggestions on how to minimise these problems. For further details on specific concepts readers are referred to the detailed descriptions in the referenced papers.

Jan 1, 1992

The current talk of risk management as a separate discipline and management function is like earlier imposition of Quality Control (QC) as an overlay on shoddy production management. Risk management is vital, but is integral in the way we marshal our staff, make decisions, then monitor and review and make crucial secondary decisions. New leaders must not assume that hiring experts ensures good decisions. It is only the essential step one. The worst company I worked for had more expertise than the best. The difference was in culture and decision-making processes. Failed feasibility studies, persistent technical factions in a company that cancel each other, heaps of expert consultant reports piled up like a dump of bricks, even great but half-managers in large and small companies cancelling expertise at their disposal, are the worst manifestations. Just daily foul-ups are common even amongst smart people. We miners have made a great industry but are content to drift far below excellence, even where that word is bandied around. All the management literature and management courses will not right the situation û we have been sending budding managers to this good stuff for two generations and the effects are worthwhile but marginal. A few key ideals, ideas and slogans are not the way. These make inspiring books that work about as long as the Christmas spirit does in the real world. What we need is a coachesÆ manual and a standard of the essential package of culture and work processes that make excellence possible and show how to maintain it long term. It has not been written until now because most managers want to remain dilettante amateur managers without the discipline that creates excellence. First, believe excellence is possible and worth any effort; then commit to it.

Jan 1, 2007

Knelson concentrators are commonly used to recover fine liberated gold in gold processing plants. The decision to employ a gravity gold circuit consisting of centrifugal devices such as Knelsons is primarily taken on the results of GRG tests, among other considerations. While the GRG test is considered a material characterisation test, which is useful in the design stages, its use in evaluating the performance of an existing unit is questionable. The problem is exacerbated by the fact that it is time consuming and costly. This paper examines the validity of the GRG test for performance evaluation and discusses alternative test work that can be performed to evaluate the performance characteristics of an operating machine. Principles that are useful in selecting optimal operating parameters, such as optimal fluidising water flow rate for a given ore/machine combination, are also discussed and illustrated with laboratory and plant data.

Jan 1, 2007

By Y Zhang

Being analysed systematically, the factors influencing the production of fully-mechanised coal face have been divided into geological, mining technical, and management groups. Artificial neural network-expert systems (ANN-ES) are established to decide the influencing factorsÆ membership grade; genetic algorithm-artificial neural network (GA-ANN) are used to decide the weights; fuzzy comprehensive evaluation method is used to calculate the integration indexes. Finally, the GA-ANN model is established to forecast the production of fullymechanised coal face. It is proved that the model is reliable with higher precision. The production of fully-mechanised coal face is influenced by many factors. However, some influencing factors are neglected by the traditional forecasting methods, the results of which are not precise and hardly be used as a guide for mine production and management. The relation between the production of fully-mechanised coal face and its effecting factors is analysed, and the meta-synthetic AI approaches are used to forecast the production of fully-mechanised coal face.

Jan 1, 2003

Many of the discrepancies that appear when comparing the results of reducing machinery are due to the nature of the materials reduced and the conditions under which they have been treated. It is therefore necessary that manufacturers should employ standard materials in their tests that sufficiently approximate the substances to be ultimately treated if the information is to be of any value to the purchaser. Another advantage to be gained by employing universal standard materials is that by their means one is enabled to compare the relative values of different types of machines. At present much of the data meted out to the public is insufficient to enable them to judge fairly. Of course the best test would be to send some of the stone tor which the machine is required, to be treated by the various crushers in the market that are likely to be suitable for the purpose, but this is not always possible. It would not take long to become accustomed to judge of the value of a machine for a specific purpose if it was guaranteed to work a certain quantity of some standard rock, even if that standard were not identical with the material to be treated.There are many points to be considered before selecting a machine, such as the size of the rough stone it will take, the size to which it will reduce it the proportions of various grades made when crushing to pass through a given mesh the form of the delivered particles the time taken to treat a+ certain quantity the horse-power required to drive the machine, both when loaded and unloaded whether constructed to crush wet or dry the wear and tear of the machine its total weight and weight of the heaviest part the cost of machine what attention it required whether the wearing parts are readily replaced, and several other points common to all machinery. 'When considering these varying quantities, we can tell at a glance certain machines that are suitable for a particular sort of work, and can then compare those belonging to the same class, thus avoiding errors made purposely or through ignotance by persons interested in different machines, who frequently compare machines originally constructed for.

By C Chen, W J. Bruckard, F R. A Jorge

The base metal industry mines and processes hundreds of million tonnes of ore per annum to produce saleable products and large tonnages of waste by-products such as tailings. These ores usually contain less than 1 wt per cent of toxic elements (As, Sb, Bi, Cd, Se, Te, Hg, etc), which are subsequently treated with the other components in the ore during the production of concentrate through to saleable metal products. The deportments of minor elements across the various unit operations of a process flow sheet do not normally receive the attention that the major elements receive. However, these minor elements can have a major influence on the quality of the products as well as an economic and environmental impact. Therefore, a high degree of control over their deportments is a key step in reducing their dispersion in the biosphere. Ongoing work at CSIRO has been examining minor element deportments across unit processes used for smelting and refining and the options for early removal of minor elements, as well as methods for safe disposal of some toxic elements. This paper provides an overview of the R&D activities undertaken at CSIRO to develop tools and methodologies for improved management of minor elements during the processing of sulfide ores.

Jan 1, 2006

The application of single liquid cement for fracture grouting in base rock may have history more than 120 years. The disadvantage of it is difficult to increase the grouting efficiency, because the jelling time of it is very long and hard to control. The double liquid grout, such as chemical grouts and cement water glass grout was developed at the end of 1960.'s Although the jelling time of this kind of grout can be controlled, it mast adopt double liquid grouting technology, use complicated equipment and is not easy to control component's ratio of the grout. Another disadvantage for chemical grout is high price, and have pollution to environment. OCE series single liquid grout is the effective grout material developed recently by making large efforts in Ohina. Main feature of it is that the jelling time is easy to control, materials from cement and clay are very cheap and without pollution to environment, and the grout can be injected by single liquid technology. The effect of QCE series grout has been proven by its application in China. It can be believed that QCE grout has great economic efficiency and will give a push to develop grout material.

Jan 1, 1988

By A Nisbett

The largest single operating loss in many hydrometallurgical plants is the poor recovery of leached product in the solids sent to tailings. Any reduction in the concentration of the valuable species in this stream will improve the project economics. Conventional design, to reduce the soluble loss, is to increase the number of wash stages or the wash/water ratio. This approach is limited in effectiveness as it can only reduce the soluble loss to that dictated by the concentration in the returning solution. For copper plants this concentration is set by the recovery in the solvent extraction (SX) plant. When using a single grade of SX feed a single grade of SX raffinate is produced generally with five to seven per cent of the copper still remaining in solution. An alternative approach has been developed by Cognis Corporation and implemented on a number of recent projects using engineering input from Miller Metallurgical Services. The SX plant feed is æsplitÆ into two different streams: a high-grade stream containing up to 75 per cent of the copper and a low-grade stream with the remaining copper. This Split-CircuitÖ concept has significant benefits in terms of both copper recovery and reduction in acid costs. The high-grade stream has the bulk of the copper removed and the raffinate sent directly back to the leach; to fully re-use the acid that has been generated during extraction in the SX process. The recycling of this higher concentrated acid stream considerably reduces the acid in the raffinate sent to washing steps. It represents a significant saving in acid consumed via the tails stream. The low-grade stream has a significantly lower SX feed grade and hence produces a lower raffinate acid and copper concentration. This lowers the economic species in the wash solution and hence reduces the soluble loss accordingly. Other operating improvements are realised with lower neutralisation costs (with the lower acid in the wash stream) and from a decreased need for in-circuit neutralisation to improve SX performance. The SX plant itself is also split into a high-grade extraction and a low-grade extraction stream to enable the low-grade raffinate to be produced. A number of circuit alternatives have been utilised that have provided a range of benefits. The circuit concept has been included into both new and existing plant operation. As a result of this experience other methods of incorporating the concept into a circuit have been developed.

Jan 1, 2005

The most frequently applied project evaluation criteria are the Net Present Value, the Internal Rate of Return, and the Pay Back Period. Unfortunately, the Internal Rate of Return and the Pay Back Period, if interpreted according to their traditional definitions, easily produce results which contradict the Net Present Value. The reasons for the Net Present Value incompatibility of the two criteria are that these criteria have not been adequately defined and so new, complete definitions are recommended. The concept of the True Rate of Return is proposed as a substitute for the interest rate that the Internal Rate of Return has been believed to represent. The redefined Internal Rate of Return and Pay Back Period criteria, as well as the True Rate of Return are all Net Present Value compatible and can, therefore, serve as independent project evaluation criteria. Also, the correct approach to the evaluation of mutually exclusive alternatives and the status of the often neglected borrowing projects in project evaluation are found to be quite important.

Jan 1, 1991

By Batterham RJ

A 'research model' can be used to investigate cause and effect relations and generally improve the understanding of extractive metallurgical processes. As such, it is a useful research technique which complements the traditional methods of laboratory and plant measurement. The procedure of model development is iterative and involves observation of the process, hypothesis of phenomena, prediction using mathematical descriptions of the phenomena and comparison of predictions with real-world measurements. Lack of agreement of predictions with real-world measurements usually indicates an inadequacy in the hypotheses and necessitates revision. Experimentation has an integral role in the process of model development but its emphasis is different from that when experimentation alone is used to study processes. Since a process as a whole is investigated by using a model, experimentation is restricted to the study of specific phenomena to aid the description of these in the model, to the characterisation of the raw materials (for initial values of the model parameters) and to the measurement of physical and chemical constants required in the model equations. Similarly, plant measurements are made for the purpose of comparison with the model predictions not to establish cause and effect relations. This makes plant experimentation much simpler and cheaper'since most measurements-can be taken during normal operation.

Jan 1, 1984

By D R. Chalmers

Coal dust explosions have occurred in coal mines across the world. The Mitsui Miike Coal Mine disaster in 1963 was an example of how this hazard was not managed effectively, resulting in the loss of 458 lives and hundreds of people sustaining permanent brain injury from carbon monoxide poisoning. Management of the risks for this hazard have been well documented and have been implemented in modern coal mines. A recent trend in some mines has seen the abolition of barriers on roadways on the basis that the risks are being managed by the current controls. These controls include stone dust application, trickle dusters, dust analysis and dust removal. This paper explores the science behind such controls and questions the need for barrier protection on belt roads.CITATION:Chalmers, D R, 2013. Cybulski revisited - Lessons on dust, in Proceedings The Australian Mine Ventilation Conference , pp 165-168 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 1, 2013

By B Roach, P M. Ashley, B Hooper

Mineral occurrences of the Hillgrove Au-Sb-W district are hosted in late Palaeozoic polydeformed, hornfelsed metasediments and Permo-Carboniferous granitoids of the NewEngland Orogen. In excess of 204 individual occurrences have been identified to date with the mineralisation developed as strike extensive (>20 km of known veining) and potentially depth extensive steeply dipping fissures. These are contained within an elongate area measuring some 9 km by 6 km in surface dimensions. Recorded gold production of 720 000 ounces along with current resources in the order of 340 000 ounces highlight the significance of this district. Historical antimony production is estimated at in excess of 50 000 metric tonnes. Significant tungsten of over 2000 t in the form of scheelite has also been produced from the field. Mineralisation is developed in veins, vein breccias, sheeted veins, network stockworks and as alteration sulfide haloes to the main structures. The vast majority of fissures are subvertical and vary in widths of up to 20 m in places. Paragenetic studies have previously indicated that the earliest mineralising event was a scheelite-bearing phase of quartz veining. Subsequent phases of arsenopyrite-pyrite-quartz-carbonate veining were accompanied by gold and minor base metal sulfides. Alteration is typically sericite-ankerite-quartz. Overprinting stibnite-quartz veining with gold-electrum, aurostibite and arsenopyrite form an important subsequent phase. Veining can be inferred from historical records to extend for vertical depths of over 1 km.

Jan 1, 2004

By Roderick W. F

The equipment and procedures used for green pellet production on a laboratory scale are given, together with a description of the straight grate pellet strand analogue which has been developed to examine the response of various ore types to heat hardening. The capabilities of the analogue are illustrated with data obtained from the balling and drying studies using a manganese ore. Differences in inter-batch pellet quality are discussed, and method of minimising the experimental error that can arise from these differences is Presented.

Jan 1, 1974

By Fredley D. C

Georgius Agricola wrote in De Re Metallica in 1556 that a prudent a miner should not work in a region ruled by a tyrant-a person inimical to mining. In 1926, Associate Chief Sherman of the United States Forest Service in a speech stated, "It is the policy of the Forest Service to encourage the development of the mineral resources within the boundaries of the National Forests ... a man who fails to cultivate a friendly, helpful, cooperative spirit in his relations with those who are endeavoring to develop the mineral wealth of our mountains has no place in the Forest Service." Both statements are as true today as they were in 1556 and 1926. The challenge to the Forest Service and the mineral industry today is to maintain that cooperation in a world that has changed significantly since Agricola and Sherman. The United States Forest Service manages 77,000,000 hectares of land-mostly in the Western United States-an area equal in size to New South Wales. The vast majority-75 million hectares are National Forests, and 1.6 million hectares are National Grasslands. National Wilderness Areas account for 13 million hectares or rough- ly 17 per cent of the National Forest System. National Forest System lands (NFS) are some of the most visible, scenic and controversial lands in the country. They are also some of the most valuable for their mineral potential and production. The value of mineral produced exceeds US$4 billion per year. There are over 1200 producing mines, 15,000 oil and gas leases, and some of the largest lead, copper, silver, gold, platinum, molyb- denum, and coal deposits in the hemisphere. Every year the Forest Service approves nearly 5,000 mineral operations on the NFS. Much of the NFS (75 per cent) is open to location of mining claims pursuant to the 1872 Mining Law. And an equal amount of land is legally available for oil and gas leasing.

Jan 1, 1991