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Copper grades of diamond drill hole and development samples are determined in the core shed logging area at Mount Isa Mine using a Bulk Mineral Analyser. All geological and grade data on the copper orebodies is collected and stored on computer file.The raw data can be manipulated interactively using a computer terminal or by input of forms to produce output as computer plots or printouts. Grade distribution of copper or cobalt is obtained by the geologist using a computer kriging package followed by grade contouring. Computer plotted cross-sections and plans of individual stopes or several stopes can be produced showing geological structures, kriged grades at points and as grade contours.

Jan 1, 1985

By Hare S. M, Lumsdaine I, O&apos

Converter slag assaying 3.7 per cent Cu is produced by Mount Isa copper smelter at a rate of up to 180 000 tonnes per annum.Priority is given to the processing of ore, however concentrator capacity periodically exceeds that of the mine and the opportunity is taken to treat converter slag. It is processed in batch campaigns, typically through the Copper Concentrator, but the Hilton Concentrator has also been used. Slag and ore are kept as separate as possible, since each has an adverse effect on the flotation performance of the other.

Jan 1, 1993

An effective production control system should maximise recovery of economic material from the resource. To do this, internal waste must be accurately delineated and efficiently removed. Achieving this is most difficult in low grade blocks just above and just below the cut off grade, where ore:waste separation follows assay or statistical, rather than geological boundaries. Difficulties arise from sampling errors, configuration of the economic mineralisation, and local variations in geology. Mine bench parameters and mining equipment size apply further constraints to the actual field separation of the ore from the waste. At BCL, management of the resource starts with an effective orebody model for planning, scheduling and ore:waste prediction. Ore production from each mining location is reconciled with concentrator tonnage and grade, and the reconciled grades are compared with the planning orebody model to highlight any Differences.

Jan 1, 1986

Selection of mining methods, stope dimensions and stoping sequences is usually based on comparisons with other similar orebodies or rocktypes. Rock mechanics principles assist the process, which can be further improved by application of rock mechanics' models - in particular, computer based stress analysis techniques. These models vary in capabilities and potential application but, basically, can be subdivided into techniques which only model the surface of excavations, and those which model the total volume to be analysed. To address the wide range of geometries, stoping methods and sequences, and geomechanical environments at Mount Isa Mines, a number of models have been developed. By presenting examples of their actual and potential application it is demonstrated that appropriate use of these techniques will assist in the determination of mining parameters and improve ore recovery. Examples presented cover sequencing in tabular and massive orebodies, location of shafts and shaft pillars, and backfill and hanging-wall stability. It is concluded that surface techniques are more appropriate for regional analyses and volume techniques are more suited to analyses of detailed, local geometry. Colour computer graphics should be an integral part of data preparation, and results interpretation and Presentation.

Jan 1, 1986

The mechanisms of fragmentation in homogeneous materials and structured rock mass are reviewed. A method previously used to predict vibration damage to the remaining rock is extended and shown to be valid for the prediction of fragmentation in the rock mass removed by blasting. The effectiveness of different explosives in different types of rock blasting is discussed.

Jan 1, 1990

Mssissippi Valley-type (MVT) and sedimentary-exhalative (SEDEX) zinc-lead deposits represent about half to three-quarters of the world's production and reserves of lead and zinc. The two deposit-types have traditionally been regarded as separate entities in terms of genesis largely because they possess very different morphologies, resulting from the epigenetic nature of MVT deposits and the syngenetic origin of SEDEX deposits. Similarities in regional setting, metal ratios, size and grade, lead and sulphur isotopes, and source(s) of fluids and metals in the two deposit-types, however, suggest that they could be products of similar genetic processes. The physical properties of MVT ore fluids suggest that certain types of SEDEX deposits could have been formed from fluids possessing similar salinities and temperatures. The hypothesis is further strengthened by the facts that: 1. in several cases MVT and SEDEX mineralisation occurs in the same region, and 2. recent advances in establishing the timing of MVT mineralisation has revealed that some MVT deposits are contemporaneous with nearby SEDEX deposits. If MVT and SEDEX zinc-lead deposits do indeed share a common ultimate derivation from fluids that emanated from sedimentary basins, then the presence of one deposit-type in a region could be used to infer the possible presence of undetected deposits of the other type. Furthermore, knowledge of the mineralisation age of one type will constrain the exploration target host rocks of the other type. A genetic relationship between MVT and SEDEX mineralisation may also explain why certain individual deposits, such as several in Ireland and eastern Canada, appear to be 'hybrids' and possess geological attributes of both end-member types.

Jan 1, 1993

Kambalda Nickel Mines (KNM) currently have eight operating underground mines, three on care and maintenance and other orebodies at various stages of development. Each operation differs greatly in scale, ore grade, milling characteristics and cost structure. The optimum number of mines operating at any one time and their level of production, within the constraints of mill blending requirements and overall mill capacity, is the key to maximising profit in a climate of fluctuating nickel price. Cost models are developed for each mining operation which relate ore tonnes mined to total cost per pound of nickel produced from that mine. Aggregating the mine cost models provides a composite cost model for the entire operation. The cost models provide the operating levels necessary for each of the mines and hence Kambalda as a whole, to operate at the lowest cost per pound of nickel produced. However, lowest operating cost does not necessarily lead to maximum profit. The level of nickel price above operating cost can dictate maximum profit positions which are contrary to the lowest cost position. In addition, the decision to temporarily shutdown mines or reopen mines in response to nickel price movements comes at a cost. In considering the optimum operating position, the price of production capacity flexibility needs to be taken into account. This paper describes the process used to assess all these factors in arriving at the optimum operating position for Kambalda Nickel Mines for varying nickel prices. The same methodology can be used by corporate management in managing multiple mine sites as well as mine management managing multiple orebodies or stoping blocks for maximum profit.

Jan 1, 1995

Gunpowder Copper Limited processes 1,000 tonne/day of Mammoth ore in a conventional flot- ation concentrator. Run of mine ore is prepared for flotation by three stages of crushing and two stages of ball milling. The concentrate, in which the primary copper mineral is chalcocite, is solar dried and exported to Japan. The history of operation is summarised, and plant practice and metallurgical problems are discussed.

Jan 1, 1974

By Bourke J. H, Ashcroft T. B

Many changes have occurred in the world market for manganese over the last five years. Among these, the emergence of divided steel processes for the hot metal refining of pig iron is affecting the use of both ferruginous manganese ore and ferro manganese, at this stage particularly in the Japanese steel industry. Subsequent demand for higher quality manganese materials is promoting the use of thermally beneficiated products such as sinter. In addition, many processes are being developed for the direct smelting of fine manganese ores, of which plasma technology is the most advanced. Cost pressures and product quality requirements are encouraging pre- viously self sufficient countries such as The People's Republic of China and the USSR to import high grade manganese ores to supplement indigenous lower quality supplies. At the same time, Brazil has been provided with the impetus to convert its substantial reserves of ore to value added products.

Jan 1, 1988

There is no other effective way for study ing firedamp and coaldust explosions than to produce controlled explosions in a pre-monitor- ed environment - either mine openings kept for the purpose, or special surface galleries. Such explosion testing facilities have been employed historically at Buxton in U.K., with lesser known installations at Bruceton, U.S.A., Tremonia, West Germany, Katowice-Mikolow, Poland and elsewhere. Both firedamp and coal dust explosions are studied. Normally coal dust explosions are initiated by somewhat standardised methane air mixtures, by explosives, or purely by coal dust. Various structures and suppression installations are installed in roadways and galleries prior to explosion to simulate destruction and suppression, and the results of such tests form the basis of suppression installations, especially stone dust barriers and water barriers. Other data collected from these experiments include rev- ersals of explosion waves, pressures and temperatures and duration of explosion waves, analyses of aftergases etc. Other uses of explosion testing galleries include testing of explosives, electrical equipment and frictional . sparking.

Jan 1, 1981

By Withington J. T

The four major contracts for the construction of Museum Station are: 1) Installation of Soldier Piles, 2) Structural Contract including the temporary support, 3) Architectural Finishes which include Electrical and Mechanical Services and 4) Supply and Installation of lifts and escalators. Specific areas of interest include the fabrication, installation and removal of temporary support steelwork, the monitoring of ground loading, and the interface between the structure and. the temporary support. The information collated during construction confirmed the design assumptions and criteria. No major changes'were required in the design of the construction methods. The open cut excavation and construction of this major structure in an inner city area was significant by any standard and was successfully completed with minimum disruption to the public and without damage to adjoining or surrounding property.

Jan 1, 1981

By Holliday R, Floyd JM

A laboratory investigation was carried out to determine the distribution of gold between the products of lead-zinc concentrate smelting in the Imperial Smelting Furnace (ISF). Bullion, speiss and slag from the ISF at Cockle Creek were used as the starting materials to evaluate the effect of gold and copper content of products on the distribution of gold between phases under conditions simulating those in the ISF hearth. The ratio of gold in bullion to gold in speiss has a mean value of approximately 1.6 and is independent of the gold content of the bullion. The distribution coefficient of gold between bullion and speiss is dependent on the copper level in speiss and is lowered by increasing copper content in speiss. The ratio of gold in bullion to gold in slag is in the range 25 to 5700 and dependent on the gold content of the bullion. For low gold concentrations in bullion of the order of 1 g/t and a bullion to slag ratio of 1:3 the gold loss to slag is expected to be approx- imately 23%. In all tests the gold in slag remained low, in the range 0.05 to 0.5 ppm provided metal prills were not suspended in Slag.

Jan 1, 1986

The Mt Whaleback open cut mine South Wall is, in part, developed as an unbenched dip slope. The remainder of the rock slope consists of asymetrical overturned folds which have been locally truncated by major low angle faults. The Mt Whaleback orebody is structurally controlled and therefore extensive structural geology input has gone into the final rock slope design. The design is based on normalised 40 m geological cross sections, but the inherent complexity of the geological structure of the orebody yields a high degree of uncertainty within that interval. There- fore, the final slope bench face and the penultimate bench faces are mapped in detail to accurately establish the geological contacts and struc- ture. The knowledge of accurate geology of final and penultimate faces plays a very important role in the design of controlled perimeter blast- ing. Accurate geology is established mainly by face mapping, and by hole geological evaluation of blastholes to locally refine the current Geologi- cal model.

Jan 1, 1989

Pbo activities have been measured in conventional blast furnace and direct smelting type slags at 1200¦C. Much higher activity coefficients than previously measured have been obtained and attributed to interactions between iron and lead oxides. The behaviour of PbO in the two types of slag reflects their relative silica contents. Simple equations derived from mathematical modelling work are presented for the prediction of Pbo activities in complex industrial slags.

Jan 1, 1984

In sizing of wet coal by the horizontal vibrating screen, screen openings to be used is much restricted, because coal is sticky and its bulk density is little. The electrically heated screen and other various types of screen had been tried to screen raw coal and coal as raw materials at a few mm. However, they failed to realize satisfactory results. On the other hand, fine sizing of coal is requested by many fields. For example, raw coal is desired to be screened at the fine rate, before being fed to the coal preparation control system in order to transport undersizes as unprepared coal particles and to reduce load in coal preparation waste water treatment system.1) Coals fed to the fluidized bed boiler also should be sized at a few mm. Regardless of many requests on fine sizing of coal, it seems that there are many cases to omit the basic screening process, because the screening is very difficult on a industrial scale. Size control as pretreatment of coal as raw materials is presented as one of the basic screening processes. In 1979, Kinki Industrial Co., Ltd. and Nippon Steel Corporation jointly succeeded in developing the vertical centrifugal screen. Closed -circuit crushing system by the use of this screen has operated actually at N.S.C, Hirbhata .Works, and realized the anticipated result. Consequently, this system has established the position as the most basic technology in the coal preparation. 2), 3), 4) This system has been also introduced to Nakayama Steel Works, Ltd. in 1982. This system termed the CPC (Coal Preparation Control) Process has been operated smoothly in both N.S.C. and Nakayama. Reported herein is the practical application of the vertical centrifugal screen termed V3-Separator. (V3 means vertical, versatile and vibration.)

Jan 1, 1984

By Shrivastava P, Humphreys M, Guibal D, Deraisme J

Customer requirements concerning the final products of iron mines are extremely stringent. Because of this, there is an ever-increasing need for mine operators to monitor and strictly control the quality of their product. This quality, as measured by the stockpile grade variability, is the result of a very complex process, where natural characteristics (the orebody and its geology) are transformed through the mining technique (open pit, shovel and truck fleet, blending into stockpile). The only way to reproduce and hence to control the variability of such a system, which is composed of several interactive sub-processes, is by simulation. A complete simulation of a Hamersley Iron Pty Ltd (HI) ore deposit has been undertaken to forecast the impact and cost of various mining methods, mining schedules and product stockpile sizes on variability of chemical and physical characteristics of the products. The mining simulation was made on a conditionally simulated orebody. On a range of criteria, the simulation was considered to fulfil the objectives set and was a valuable aid to analysis of product grade variability, operating and capital costs, selection of equipment, mine scheduling and setting of product grade targets.

Jan 1, 1994

By Will D

This presentation is to outline the current practice of mechanised stoping a one-metre wide, gold bearing ore body to optimise fragmentation, minimise dilution and reduce stoping costs.Coolgardie underground operations have historically been mined using traditional shrink stope methods, but in this recent economic environment (with falling gold prices and high costs of traditional methods) it was necessary to look for alternative methods in order to reduce costs and increase productivity.Although still in a learning and refinement phase, CGNL is satisfied that it is feasible, practical and more economic to use mechanised long up-hole stope and long-hole rising methods to significantly reduce the mining cost, reduce dilution, increase safety and increase productivity three-fold compared to traditional airleg methods used throughout the Fasten Goldfields.

Jan 1, 1993

By Schofield D, Denby B, Stout F, Moli A

This paper documents the development of a user-friendly computational program, which has been constructed to assist the mine ventilation engineer in the optimal design and operation of methane drainage ranges. In the past, many computer tools for ventilation engineers led to the development of `research systems'. These computer systems, although developed with the needs of the industry in mind were due to a combination of inexperienced programming methods and the availability of suitable user interface software not easily accessible to the practising engineer. Recent developments in computer hardware and software (particularly windows based graphical user interfaces) mean that engineers no longer need to dedicate large amounts of valuable time to become familiar with often complex items of software. The authors of this paper intend to demonstrate a practical system which successfully integrates complex mathematical models, an easy to use interface and knowledge based techniques. The graphical interface guides the user to draw on the screen a mimic diagram representation of the methane drainage network. The user is prompted, during the construction of the drawing, to input the information and data required by the calculation and knowledge based procedures. The computer program then calculates all of the flows, purities and pressures throughout the network. Given reliable measured data from an existing range a comparative analysis can be performed between the predicted and measured network flow data. A knowledge-based system may utilise this analysis to either update the operational status of the network or suggest either a reasoned maintenance or remedial strategy to improve the performance of the drainage system. The development of the OMEN project has been carried out at the request of the Midlands Group, British Coal Corporation, Edwinstowe. The system is about to be field tested at a number of mines. It is hoped that when this paper is presented that the system will be used at both Group and mine level.

Jan 1, 1995

The Hellyer deposit, hosted in the Cambrian Mt Read Volcanics, displays features typical of volcanogenic massive sulphide orebodies. These include a well developed stringer zone, metal zonation within the orebody, a polymict volcaniclastic sequence flanking the deposit and a hangingwall alteration plume in overlying basaltic pillow laves.Mapping and core logging is very detailed in order to extract as much data as possible from the deposit and its host rocks. A geological log suitable for direct computer input was adopted shortly after the deposit's discovery.

Jan 1, 1990

By Alwan M

At Binebase mineralisation is hosted within an andesitic Neogene volcaniclastic succession on Sangihe Island, Indonesia. Two major alteration types occur; an initial widespread phyllic assemblage of quartz -illite with chlorite, smectite, gypsum and pyrite, and a superimposed quartz - barite - sulphide assemblage. The phyllic alteration arose from a neutral to weakly acidic hydrothermal solution of greater than 200 degrees C, and the quartz - barite - sulphide assemblage arose from a cooler slightly more acidic fluid. This second alteration event is interpreted to have selectively replaced permeable volcaniclastic breccias and coarse lithic tuffs within the altered sequence. Gold and silver mineralisation is associated with the latter alteration, and is locally controlled by the degree of silicification and sulphide abundance. The sulphides present are pyrite, covellite and chalcopyrite. The sulphides are very fine grained with colloform and framboidal textures and were deposited contemporaneously with the bulk silicification of the coarse sediments. A large portion of the mineralised rock has been oxidised to a quartz - barite -limonite - goethite - jarosite assemblage.Coincident gold, silver and antimony geochemical soil anomalies gave the best correlation with anomalous gold and silver grades in bedrock as identified by drilling. Resistivity proved a reliable geophysical method for delineating zones of silicification.

Jan 1, 1990