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By Fisher WJ

The'treatment of the South Alligator valley uranium ores passed through three phases dictated by economic circumstances during the years 1956- 640 In the first phase high grade ores were treated by hand sorting and wet gravity separation for recovery of high grade concentrate to meet a United States Atomic Energy Commission (U.S.A.E.C.) contract for plus 50 per cent pitchblende concentrates. Secondly tailings from the gravity plant and some high grade ores were trucked to Rum Jungle and sold to the Australian Atomic Energy Comm- ission (A.A.E.C.). Thirdly solvent extraction plants were built at Moline (previously Northern Hercules) by United Uranium N.L. (UOU.N.L.) and at the South Alligator River by South Alligator Uranium N.L. (SOA.U.N.L.). These were the first solvent extraction plants designed in Australia, as earlier plants used the ion exchange process for recovery of uranium oxide. The plants were small, indeed the S.A.U.N.L. 15 ton per day plant was possibly the smallest commercial plant known, but they operated efficiently with good recoveries, and were placed on a care and maintenance'òbasis when contracts were filled. Sulphuric acid was supplied in bulk to both plants by the A.A.E.C. from the 30 ton a day acid plant at Rum Jungle. Gold was recovered as a by product of uranium ore from the Moline plant.

Jan 1, 1968

Before commencing design of a coal prepar ation plant, it is essential to have detailed information of the raw coal to be treated to- gether with a clear understanding of the products required. Prediction of raw coal size distribution, particularly the amount of fine material, is difficult and the methods employed should be large scale pilot plant studies or techniques to simulate coal degradation and shale breakdown in water. A detailed knowledge of well proven coal preparation processes and new developments allows processes and process combinations to be compared to'obtain the maximum economic recovery when using lower cost, less efficient processes within acceptable limits. Equipment should be selected bearing in mind its precise application and the location where it is installed. Plant layout should be carefully studied to minimise equipment requirements and to simplify construction. Measurement, control and automation should be an integral part of plant design in order to obtain the optimum performance of the processing equipment.

Jan 1, 1974

Kalgoorlie Consolidated Gold Mines Pty Ltd (KCGM) is a management company, formed in 1989, to manage the assets and operate the Kalgoorlie joint venture for the owner companies Gold Mines of Kalgoorlie Limited (GMK) and Homestake Gold of Australia Limited (HGAL). Mining is still in progress on the 'Golden Mile' and surrounding areas more than 100 years after Paddy Hannan's discovery adjacent to the active Mt Charlotte mine. From 1893 until 30 June 1995 the Kalgoorlie Goldfields has produced approximately 45 million ounces (-1400 tonnes) of gold from mining and treating about 179 million tonnes of ore. This production equates to about 20 per cent of the total Australian gold production and about one per cent of the world's

Jan 1, 1996

The investment worth of a mineral deposit can only be realistically evaluated in relation to specific engineering design criteria, which fully details the proposed method of exploitation. These criteria have not in general been taken into serious consideration when leaseholders have reported reserves in the past. In fact, many "reserve" figures quoted are probably more correctly classified as geological resources. The industry now recognises that it is necessary to take into consideration not only grade and mill recovery factors, but also likely mining and processing costs as well as the current market price for the commodity. Once having estimated those costs which are applicable to the resource under study, they can be deducted from the gross inherent worth of the orebody to result in an estimate of the potential net revenue. Through a process of interactive trial mine designs and evaluation, reserves can be quantified to provide an estimate of the available recoverable economic reserves given a set of assumed cost and operational parameters. It follows then, that the available economic reserve recoverable from a given resource will vary from time-to-time as cost and price factors vary in response to changing technology and economic factors. A methodology is described which may be used to derive economic recoverable reserves based on a computerised model of the geological resource data and appropriate economic and operational cost algorithms. Examples are provided from both coal and gold studies to illustrate the impact of economic criteria on the magnitude of the reserve figure reported for each project.

Jan 1, 1987

Better quality at lower cost is today's formula for remaining competitive in a world market. For an integrated steel company, high quality low cost steel production must originate before the blast furnace. In 1979, when U.S. Steel initiated a Quality Management Program throughout its steelmaking operations, efforts began at the coal, ore and flux mines. The objective was to improve the quality and reduce the variability of the critical parameters for steelmaking raw materials, to get the blast furnaces, and subsequently the melt shops, under optimum control. The general details of U.S. Steel's Quality Management Program are discussed and how it was used to promote the desired improvements in steelmaking raw materials. Some of the outstanding results obtained by the cooperative efforts between the mines and the steel plants are reported. The lessons learned by U.S. Steel were through upgrading existing operations and facilities. These principles should now be applied to new projects and the benefits of good quality management should commence from the time new projects are Commissioned.

Jan 1, 1986

Projected cooling requirements for ERPM led to the first proposals for the large- scale use of ice for mine cooling in the early 1980's. Following successful research into ice conveying and ice melting a large ice plant was commissioned at Harmony in 1985 and a much larger 6000 ton per day plant is presently under construction at ERPM. A brief description of the mining project is given, followed by general descriptions of the surface ice plants and the ice conveying system, the systems for using the ice for mine cooling, and the control of the whole ice cooling System.

Jan 1, 1988

The resources industry is unique in that the finite nature of resource deposits requires a participant to be constantly locating and developing new ones to replace those that are depleted. An effective growth strategy that enables new project developments to be brought on line in time and within budget is therefore of fundamental importance to any mineral resources company. This paper seeks to identify the role of the development project in the company's overall growth strategy and the key performance criteria that a development project must achieve in order to allow a company to meet its growth objectives.

Jan 1, 1997

Blasting is known to be both an important and an easily quantified cost factor in rock breaking operations. However, the indirect costs and benefits of the blasting operation are not easily determined due to the irreversibility of the mechanisms involved and the multiplicity of influencing factors. A general conceptual model showing the relationship between blasting and mining costs is well known, but serious attempts to address the critical real relationships have all floundered on the fact that not enough is yet known about either detonation physics or blasting effects. This can only be remedied to the extent that blasting instrumentation enables researchers to pin down not only the relationship between the detonation process and its impact on a particular environment, but also the downhill costs of handling the rock, repairing any damage and building in "Safety Factors" to provide for imponderables. It is vital to standaraize on specifications for instrumentation and measurement techniques and there is a need to review what has been achieved in blasting expertise so as to focus on the most fruitful paths for future work.

Jan 1, 1990

This paper is a summary of the general theory of sampling published by the author in 1975. Sampling is a random process and its the- ory is a study of the, numerous errors liable to take place in the course of its realization. A complete sampling scheme is a sequence of sampling (proper) and preparation stages . At each stage, the total error ET is the sum of : -.Sampling errors EE arising from the selection process itself. -Preparation errors EZ arising from the operations (crushing, transfer...) sup- ported by the sampled material. ET a EE + EZ . At each sampling stage, the (total) sampling error EE is the sum of seven inde- pendent errors : - Weighting error ED resulting from the non-uniformity of the density or rate-of-flow of the sampled material. - Integration error EI1 resulting from the long-range distribution heterogeneity of the sampled material. - Periodicity error EI3 resulting even- tually from periodic quality variations of the sampled material.

Jan 1, 1976

By Locke CA

Geophysical signatures of the Taranaki and Tongariro volcanoes reflect similarities in their age, composition and hydrothermal histories, but also reflect differences in host rock settings and edifice evolution. The Taranaki volcanoes have strong positive gravity anomalies showing that their edifices largely consist of dense andesite which reflects substantial lava production or dyke injection during construction and that large sub-edifice dykelstock complexes occur. In contrast, the Tongariro volcanoes have strong negative gravity anomalies indicating low density edifices of volcaniclastic material; no sub-edifice intrusions can be identified, probably because of the lack of density contrast with host basement rocks. Strong positive magnetic anomalies over the younger cones can mainly be attributed to near-surface andesite lavas or dykes whereas subdued magnetic effects are associated with hydrothermally altered zones within both edifices and sub-edifice intrusions.

Jan 1, 1995

Diamond drilling was first carried out at Norseman in the Princess Royal Mine, early in this century. Little concentl'ated drilling was done from then until Western Mining Corporation commenced drilling in 1934. Since then Central Norseman Gold Corporation N.L. has continually employed diamond drilling in exploration of the field. After 1946 the advantage was seen of applying broad pattern surface drilling at Norseman in the reef exploration. In 1953, as a result of the steeply rising cost of drilling and the time taken to penetrate surface material by light equipment, heavier drills and new rigs were introduced. The surface drilling programmes called for a greater monthly or annual footage and to satisfy this new techniques were introduced. The Mitchell-21 machines were discarded and A-3000 machines were installed, firstly under a 48 ft. fixed tower, then mounted on a truck with a 20 ft. tower, and finally on a truck carrying a 40 ft. tower. With the mobile units a compressed air compressor is attached. By use of compressed air with either the Reed roller or Hawthorne bit, rate of penetration of overburden is greatly increased. The mobility of the truck mounted machines has greatly reduced the time required to move from one hole to another, and the use of heavier machines on a three shift per day basis has considerably increased the footage per shift. The general result is an increase to 1,500 ft. of drilling per month per machine, while costs have been greatly reduced in spite of increased wages and diamond prices.The underground drilling technique is described. Analysis of performance has not been made because the drillers performance is subject to shaft routine and service.INTRODUCTIONGold was first discovered at Dundas in 1894, and at Norseman, 14 miles north, in 1895. From that tirpe until 1935 mining activity fluctuated. Following the mining revival in 1935, production in the field has remained comparatively stable. This stability in part has been due to the broader scale of operations of Central Norseman Gold Corporation N.L., and in these operations diamond drilling has played an increasingly important role.

Jan 1, 1956

Peko Mines, a Division of Peko-Wallsend Operations Limited (PWOL) has operated several small underground mines in the Tennant Creek district of the Northern Territory supplying ore to a central treatment plant. The Argo Mine is the most recently developed by Peko Mines. A magnetic anomaly was identified from low level airborne magnetics in 1960 and drilling, which commenced on the site in 1969, was halted in 1974 and resumed in 1980 following the rise in the price of gold. By mid 1983 a resource of + 200 000 tonnes of 12 g/tonne Au had been outlined and a decision to develop the resource was taken following the drilling of three further diamond drill holes which did not significantly alter the value of the resource. The small size of the orebody could not support the full capital cost of two shafts and a single entry mine plan was developed to extract the ore at a rate of 15 000 tonnes per month and to provide all the safety features, ventilation systems and services of a two shaft mine. In December 1983 a contract was let to Allied Constructions Pty. Limited (Allied) to sink and equip a 4.8m shaft to a depth of 410m and to convert the headframe and winder, which are leased for the life of the mine by PWOL from Allied, from a sinking to a production configuration. Shaft equipment designed by Hardcastle & Richards Pty. Ltd. (H & R) in conjunction with PWOL includes a skip/cage, counter- weight, and an auxiliary cage on rope guides, a sealed ladderway and exhaust air ducts.

Jan 1, 1986

By Burnett C. C H

GEMNet, (Grade Estimation using Mapping Networks), is a grade/reserve estimation software system that uses the artificial intelligence technique known as neural networks to perform reserve estimates from both two- and three-dimensional data samples from a mineral deposit. The system is the result of research carried out over the past three years into the feasibility of using neural networks for reserve estimation at the AIMS Research Unit in the Department of Mineral Resources Engineering at the University of Nottingham. This paper describes the architecture of the GEMNet system including details of the neural network components of the system. The performance of the GEMNet system is then compared to several other widely used reserve estimation techniques on two reserve estimation examples. The results produced by the GEMNet system compare favourably with more conventional estimation techniques, but require fewer assumptions to be made about the form of the data used, and do not require the use of complex mathematical modelling.

Jan 1, 1995

By E Werner, J J. Donovan, A J. Morris

Coal mining in the Pittsburgh coal seam, in the eastern United States, began in the late-1700s. Since that time numerous mining technologies have been used throughout the basin. Environmental concerns, particularly mine discharge quality, have only been considered since the early-1970s. During the last 20 years, many of the larger underground mines have closed and are now either flooding or already flooded. In order to understand the consequences and potential future effects of this flooding, mine mapping of the basin has been compiled utilising a geographic information system (GIS) with an emphasis on locating barrier pillars between mines. Mine flooding has been monitored at numerous sites utilising pressure transducers and data loggers. These data have been combined with historical data from mining companies and structure contour maps to yield chronological flooding maps of the basin from 1980 to present. Utilising these maps and the indicated flooding rates, future discharge locations have been identified along with estimates of when these discharges are likely to occur. Related work has identified barrier pillar hydraulic conductivities and vertical infiltration rates as a function of overburden thickness. All of this information has been integrated into a groundwater flow model that simulates mine flooding. This model is useful in defining mine to mine interactions as the various mines fill with water, and the testing of various flooding scenarios. The model will be used in evaluating mine discharge rates and evaluating the options for regional mine drainage treatment.

Jan 1, 2003

Market forces, particularly iron ore prices, demand that plant operators achieve higher throughput in the worldÆs iron ore beneficiation plants without compromising yields or efficiency. This means that production cost per ton is of paramount importance and that all major pieces of Processing Equipment have come under close scrutiny to improve throughput at their most efficient performance levels and for the longest possible continuous running time. Without doubt the use of modern engineering standards and materials of construction has contributed to matching these throughput, efficiency and availability demands. However, often not enough attention is paid to the so called æinsignificant elementsÆ connecting this metallurgical equipment, such as chutes, pipes or other conveying systems, and particularly to the sufficient protection of their wearing surfaces. The result can be an unplanned and expensive outage caused by the wear related failure of such components. This paper will discuss:the theory of wear and the multiple factors of material and design that contribute to a reduction in wear; and the combinations of modern wear resistant materials available to todayÆs engineer and how, by intelligent selection and correct application, plant availability can be optimised. Examples outlining how these principles have been applied in South Africa showing some improvements leading to increased plant availability.

Jan 1, 2002

By Gray J, Krouse HR, Changkakoti A, Kwak TAP

The Dachang tin field with more than one hundred million tonnes of ore at 1% tin and 3% Zn is one of the largest tin fields in the world. It comprises five carbonate replacement tin deposits, of which the Changpo deposit containing about 80 million tonnes of ore at about 1% tin is the largest deposit. The deposit, hosted by middle Devonian limestone, argillaceous limestone and black shale, is genetically related to the Longxianggei granite.The oxygen, hydrogen and carbon isotope data of minerals, rocks and fluids suggest a magmatic fluid which evolved during the crystallization of the Longxianggei granite. Mass balance calculations show that the depletions observed in 180 and 13C values of calcites from the ore bodies to the country rocks were due to continous isotopic exchange reactions between the magmatic fluid and the marine limestones at different W/R ratios and between 300 and 600¦C.

Jan 1, 1990

Solar Salt, Lunar Ambitions I Bauerti The title of this paper is `Solar Salt, Lunar Ambitions'. It is largely the result of a lack of imagination and a tight deadline. I was seeking a catchy title to convey the image of being 'here' and wanting to get `there', with `there' being a long way away and our being held 'here' by powerful gravitational forces. I tried `Solar Salt, Lunar Landings', but that implied we had already reached `there' when, on reflection, we had not. A colleague suggested 'Solar Salt, Luna Park' which is a fun park in Sydney and, I must admit, there was appeal in the image of having embarked on a wild roller coaster ride with stomach-wrenching twists and turns and the only reward being a pair of sweaty palms, and a feeling of nausea. That's sometimes how it feels when you launch into change. In the end I settled for the more sedate `Lunar Ambitions'. It contained that suggestion of hope and continual striving which are central to the idea of best practice. I will discuss our experiences in this area shortly, but I would firstly like to provide some background to our business. The salt industry is steeped in history and tradition. As one learned commentator observed, common salt is 'a substance seemingly too ordinary to think about, yet it is the oldest of man's raw materials and the basis of some of his newest inventions' (Multhauf, 1978). From ancient times, salt was recognised as a key necessity of life and it has played a role in the rise and fall of governments throughout history. The Romans recognised its importance when they gave their soldiers money regularly to purchase salt, hence our modern word 'salary'. Today, while culinary use remains important, the main consumer of salt is the chemical industry (Figure 1).

Jan 1, 1995

By M Dorricott

This paper describes the design, construction and performance of sill pillars using cemented development mullock at the Crusader Gold Mine. The orebody is some 35 m - 60 m in length, 5 m - 8 m wide, dipping at 60¦ - 85¦ and plunging at about 40¦ to the north. It is accessed via a footwall decline. The ore occurs at the contact between basalt and ultramafic. This contact is characterised by shearing and alteration; and is prone to unraveling failure. The cut and fill mining method at Crusader extracts 25 m high ore blocks in four flat back lifts and one 8 m thick crown pillar. To enable full recovery of these high-grade crown pillars with minimal dilution, a 5 m thick sill pillar is constructed using cemented rock fill (CRF), after mining of the bottom two lifts in each block. Uncemented development mullock is used as rock fill (RF) for subsequent lifts. Development mullock and cement/water slurry is mixed underground to produce CRF. The fill is transported to the stope in LHDs and dumped on the floor. The sill pillar is advanced progressively, with compaction provided by the loader driving over the previously placed fill. Old jumbo rods are installed as shear pins along the flat dipping hangingwall to reduce the risk of rotational failure of the pillar. A fan of cable bolts is installed into the hangingwall to prevent unraveling failure in the sheared ground. Buffer blasting is used to minimise damage to the CRF sill pillar when the crown pillar below is extracted. At the time of writing, extraction of the crown pillar underneath the CRF has taken place at the 930 stope. The crown pillar was extracted successfully with dilution from the backfill and hangingwall minimised and 98 per cent of the gold recovered. This compares with pillars that were mined beneath uncemented backfill where only 70 per cent of the gold was recovered and where there was significant dilution from the backfill and from hangingwall failures. Where no CRF was placed, there were also numerous production delays caused by large rocks from the hangingwall blocking the stope brow.

Jan 1, 2002

The primary object of this paper is to describe the present metallurgical practice of the Emperor Combined Mill, wherein ores from the adjoining and Associated Mining Companies, Emperor Gold Mining Company Ltd., Loloma (Fiji) Gold Mines, N.L., and Dolphin Mines, Ltd., are treated for the recovery of gold and silver.The mining field is located in the foothills, five miles from the sea, on the northern side of Viti Levu, the largest and most important island of the Fiji group.The orebodies occur in basalt and associated ash beds overlain by andesite, tuffs and sediments. The basalt is a dark greenish-black rock and in much of the ore mined is weathered with alteration of the olivine to serpentine and iron oxides, of the augite to chlorite and of the minute included crystals of iron ore to other iron oxides. Into the basalt intrudes a considerable number of andesite dykes, and the lodes occur as veins in these dykes, as "flatmakes" along fissures or, ash beds extending horizontally from the dykes and at the contact of the basalt and the andesite dices.The Emperor orebody is the largest and most important, and consists essentially of massive, shattered, well altered and mineralized basalt.Little or no free gold occurs in the ore at present being milled, the most important host minerals for gold being the tellurides sylvanite and hessite, next in importance being the sulphides, pyrite, marcasite and arsenopyrite. Chalcopyrite is present in quantities large enough to be troublesome in the subsequent concentrate treatment section, while sphalerite, tetrahedrite, bornite, galena and native tellurium are present in small quantities.Unimportant occurrences of native copper have been observed in both Dolphin and Emperor orebodies.

Jan 1, 1953

By Williams SR

Column Flotation cannot be used indiscriminately. Based on extensive pilot plant experience at Lakefield Research, a number of limiting parameters have been identified for the application of column cell flotation. Parameters of importance are the use of wash water, flotable mineral content, pulp viscosity, type of mineral selectivity being sodght and degree of mineral liberation. The paper discusses when wash water should be used and the positioning of a column within the circuit as this is important to maintain a sound water balance for the circuit and prevent excessive circulating loads. Other areas of debate are pulp chemistry, very low and high weight recovery, for which the conventional column is a poor selection of equipment, and treatment of complex ores, where the separation of valuable minerals is more difficult than non-sulphide, sulphide mineral separation. Based on these observations, the application of column flotation must be carefully considered or can be optimised.

Jan 1, 1993