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This paper gives a description of the methods of mining employed at North Broken Hill Limited, Broken Hill, N.S.W.GEOLOGICAL NOTESThe main Broken Hill lode occurs as a replacement of tightly folded pre-Cambrian sediments. Replacement has followed certain stratigraphical horizons and the main bulk of the ore is found where these have been packed into the noses of anticlinal and synclinal folds.Throughout the mine the ore-bearing folds pitch north fairly consistently at 45 degrees, as a result of which two favourable horizons in the same fold appear in plan as separate orebodies and these are referred to as the "Southern Orebody" and the "Northern Orebody" respectively.The general dip of the orebodies to the west is about 60 degrees. A typical sill is shown in the plan of the 1,400-ft level (Fig. 1).Both the hanging wall and footwall rocks throughout the mine are weak and, as a result, it is necessary that the hanging wall must be well supported after ore extraction, to prevent subsidence. The weakness in the footwall is confined to a narrow zone, approximately 60 feet in width. This weaknes.q is a source of trouble in the development headings which pass through it, It is sufficiently crushed to transmit weight from the overlying wall to the gangways below.Another feature causing ground instability is the presence of many faults. Although their effect on the shape and character of the orebody is relatively small their...

Jan 1, 1940

By D David

Amongst those whose task it is to design tumbling mills and other comminution machines there is an almost religious divide between devotees of the Bond method and devotees of other methods developed in more recent times. For a decade or so the issue was between the Bond power-based methods and the JKMRC (JK) simulation based approach. The newest method to challenge the status quo is power-based and was developed by Steve Morrell. As the title suggests, this paper will take some liberty at concluding that Fred Bond and Steve Morrell may be separated by history, but not by their approaches to their individual contributions to the science of comminution. Another driver for the paper is that although it is good to have diversity of thought, the existing divisions are problematic for those of us signing public disclosure documents. If alternative design methods produce materially different outcomes for the mill duty, then at least one of them is wrong or being used incorrectly. At some point the unsustainable argument may need to be put in a court of law that we metallurgists have two or more materially different design methods, each of which is correct! Therefore, perhaps a resolution is needed before this occurs?The works of both Fred Bond and Steve Morrell are each directly related to their contemporary grinding mill design and operational environments. Both their approaches are empirical, borne of observing and measuring real world situations. Both worked with theories that preceded them, gathered their own data and then each saw shortfalls in the status quo.Fred Bond was an escapee from revolution, a victim of The Great Depression, and had several near death experiences during his early site-based career. Perhaps he was fortuitously rescued from himself when asked by Allis Chalmers (A-C) to set up its rock testing laboratory in Milwaukie in 1930. Fred’s testing led him to conclude that neither the Kick nor the Von Rittinger theories explained his measurements. His writings on the failings of these old theories caused a divide between devotees of the old and new methods at that time. After many years, and much thought and plotting of data (the old way!), he came up with his now-famous equations (and his Third Theory) which have stood the test of time, certainly in the world of Bond-era machines.Coming from England via several African diamond mines, Steve Morrell immersed himself into the comminution world of the JK in Brisbane about a decade after Fred passed on. The JK had developed its semi-autogenous grinding (SAG) simulation framework using its own pendulum breakage tester, itself a derivative of the twin pendulum impact device invented by Bond decades earlier. At the JK Steve developed his authoritative Tumbling Mill Power equations and was involved in real world analysis of comminution problems on the global stage. Steve’s JK experience coincided with the demise of the rod mill, the rise of autogenous grinding (AG) and SAG milling and a rapid expansion in concentrator capacity.Morrell left the JK to pursue his own interests, which included ongoing consulting work, now demanded by the comminution world. He then turned to investigating a growing list of discrepancies between the opinions of designers and theoreticians, and the factual outcomes. The Morrell Method of design arose from this re-examination of ore testing, real world operating data and these glaring and expensive discrepancies between design and outcome. The elements necessary for a relook at the world of rock breakage were in place!CITATION:David, D, 2017. Steve and Fred would have been mates – a comminution design evolution story, in Proceedings MetPlant 2017, pp 2–11 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

Using Mineral Maps to Rank Potential Processing Behaviour

Sep 13, 2010

Great new drilling results! What's so sinful about being a multi-national company? Overseas protestors flown to Australia for a free holiday How to counter the protectionist danger? Our current economic standing Over-regulation puts a convicted paedophile on the payroll The broken window fallacy Mining - A shared history Aristotle and the camels A brighter future? Something over which we do have far greater control, i.e. leadership within our own industry My challenge to you The expanding gold- producing company of which I am proud to be Chairman, Croesus Mining NL, is by definition a æmultinationalÆ. Our shareholders are based in 36 different countries, 77% of our 107 million shares are held in Australia, 23% are held outside Australia, and include New Zealand holdings of 7%. In September, Croesus Mining presented our company at the Mining 2000 Forum in Melbourne, a city caught up with multinational protestors demonstrating against multi-national companies.  

Jan 1, 2000

By Woodcock J. T

When an aqueous suspension of pyrite and manganese ore reacts with oxygen, manganese is dissolved by the ferrous sulphate and sulphuric acid produced by the oxidation of pyrite. The kinetics of certain steps in the overall reaction were studied. A rate equation for the oxidation of ferrous sulphate by gaseous oxygen was derived for the temperature range from 1000 to 200° C. An exact rate equation for the production of ferrous ion from pyrite could not be established but it was shown that the temperature, oxygen pressure, pyrite surface area, and the reduction of ferric ion by pyrite are important. A rate equation was derived for the reaction of manganese dioxide with ferrous sulphate. A major facfor controlling the rate was whether or not ferric oxide was formed by hydrolysis at the manganese dioxide surface.It was shown that if hydrolysis was prevented the factor cpntrolling the rate of the overall reaction ,was the rate of production of ferrous ion, and little ferrous ion was oxidised by oxygen. When hydrolysis of iron did occur, the overall rate was not a simplefunction of anyone factor and much ferrous ion was wasted by oxidation with oxygen.INTRODUCTIONIn another paper (Cornelius and Woodcock, 1958) the results of the reaction of an aqueous suspension of a manganese ore and pyrite with oxygen are reported. It is shown that the ferrous ion and sulphuric acid generated in situ by the oxidation of pyrite, dissolves manganese as manganous sulphate. To obtain a better understanding of the process as a whole, the kinetics of certain steps in the overall reaction were studied.When an aqueous suspension of a manganese ore and pyrite reacts with oxygen, the overall reaction may be conventionally represented by equation (1) (Cornelius and Woodcock, 1958).2Mn02 + 2FeSz + 6i02 + 2HzO= 2MnS04 + 2H2S04+ F'ez03 ... , .. (1)

Jan 1, 1958

A computerised cataloguing system for geological specimens is described. The catalogue is designed for use with a compactus-type storage system. The information stored in the catalogue for each specimen includes the type of specimen, locality information in terms of standard ~ap sheets and descriptive location, geological age, stratIgraphy, and specimen descriptions. The catalogue can be interrogated at any level of detail on the basis of any combination of these specimen parameters.Other information stored for each specimen 'is the compactus address, collection date, reference information and the type of analyses performed on that specimen:Any mterrogatlon produces a listing of those specimens which satisfy the search criteria.

Jan 1, 1974

Real Time and In Situ Measurement of Elemental Composition Using Lasers

Sep 13, 2010

Modelling Channel Scale Flow in Heap Leaching Using Smooth Particle Hydrodynamics (SPH)

Sep 13, 2010

A pyrite flotation concentrate assaying 0·065 oz/ton gold was investigated to determine the mode of occurrence of the gold. Ftom cyanidation and acid leaching experiments it was concluded that O· 02-0· 03 oz/ton goldwas in solid solution in pyrite and the balance of the gold was finely dispersed as grains throughout the pyrite.Autoradiography and electron-probe examination of possible areas in briquetted concentrate did not detect any grains of gold. Neutron irradiation and gamma spectrometry confirmed on 100 mg samples the fire assays obtained on 1 assay ton samples.Oxidation to hematite and reduction to magnetite at 600°C made practically the whole of the gold extractable by cyanide. This technique could be of major significance for gold ores which contain a substantial amount of "refractory" gold.

Jan 1, 1969

By R Dwyer, S Rea, W J. Bruckard, N McSweeney, R Holmes

"The innate ability of microorganisms to adapt to changing or inhospitable environments has often been exploited for industrial purposes and forms the basis of many current biotechnological processes. The ability of bacteria to adapt and adhere to specific mineral surfaces ensures that the energetic or nutritional requirements of the cell are met and often serves as a survival mechanism under unfavourable?growth conditions or conditions of stress. In this process, cells may rearrange or modify the macromolecules expressed on the cell surface itself or produce extracellular molecules, modifying mineral surfaces to render them more suitable for growth. The modifications that these molecules produce on mineral surfaces may result in changes to the surface charge and hydrophobicity of a mineral. As a result, these biomolecules may have some potential application as flotation collectors or modifiers.In this work, the effect of long-term exposure of Paenibacillus taiwanensis to goethite and common gangue minerals associated with Australian iron ores on the differential expression of membrane and extracellular proteins was determined. Both groups of proteins play a role in cell adherence to mineral particles. Cells were adapted to grow in the presence of each mineral over time. The proteins expressed on the cell membrane and the extracellular proteins excreted by the cell were isolated and analysed by two-dimensional polyacrylamide gel electrophoresis (2D gel PAGE). The outcomes of these studies are presented here and potential application of these products for flotation discussed.CITATION:Dwyer, R, Rea, S, McSweeney, N, Bruckard, W J and Holmes, R, 2013. Microbes and their metabolites - potential iron ore flotation reagents, in Proceedings Iron Ore 2013, pp 369-372 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 12, 2013

Laboratory and pilot plant investigations aimed at recovering gold as an electroformed sheet from gold eluate and gold leach solutions and slurries are discussed. The electrolytic test work undertaken makes use of high surface area electrodes, in particular nickel-chrome foam metal and activated carbon, as well as ultrasonic activation. The process involves initial gold electrowinning (or adsorption onto activated carbon), followed by gold electroforming, both operations being carried out in a specially designed reactor. The pilot plant work mainly involved the treatment of gold eluate solutions from a South African gold mine containing 600 mg/L Au: some tests were also carried out on gold leach solutions containing 6 mg/L Au. In the former case, very efficient gold extraction onto the foam metal cathode was achieved using electrolysis combined with ultrasonics. The polarity of the gold-loaded cathode was then reversed and, using a replacement electroforming electrolyte, gold was electroformed in situ onto a polished stainless steel mandrel, from which gold sheet was subsequently removed. In the case of leach solutions, pilot plant tests confirmed laboratory findings that in the presence of calcium (resulting from the lime used during the leaching process) no electrowinning is possible. Laboratory tests showed, however, that when sodium (in the form of NaOH or Na2CO3) is added to the leach solution, electrowinning can indeed take place. Alternatively, if a special activated carbon electrode is used (without current), the non-ionic calcium aurocyanide complex is adsorbed on to the activated carbon. When a gold-loaded activated carbon electrode is made anodic in a gold electroforming electrolyte, gold electroforming is feasible, although the efficiency is very low. The possible implications of these developments for gold recovery are further examined.

Jan 1, 2007

By A Jewbali, J Phillips, C Boyle

Normal practice in the mining industry is the creation of a single geological model. These models provide a single interpretation of the geological and mineralisation domains. These interpretations infer the exact behaviour of ore domain contacts at shorter scales when resource definition drilling is done on wider scales and are thus locally highly uncertain. The interpreted geological model provides a single number for the volume and tonnes of mineralised material enclosed by the mineralisation envelope. It is on this single number for volume and tonnage that capital intensive mine development decisions (mine design and scheduling, stockpile strategy, waste management, closure planning, dewatering strategy, product quality, etc) are based. Some of these decisions require knowledge of grade variability for small volumes of material such as quarterly production periods. It is generally recognised that this information cannot be derived from single kriged geological models, but can potentially be modelled by conditional simulation techniques. Uncertainty in the extent and continuity of the mineralised envelope and its effect on grade variability for shorter production periods is thus recognised as a major source of uncertainty in new mine development.CITATION:Jewbali, A, Boyle, C and Phillips, J, 2013. Quantifying domain uncertainty for an iron ore deposit, in Proceedings Iron Ore 2013 , pp 157-168 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By R McDonough

DTL2 contract C916 was awarded in March 2009 for S$340 M. This contract includes two mass rapid transit (MRT) 1100?m long bored tunnels using two slurry tunnel boring machines (TBMs), with an internal diameter of 5.8?m, two cross passages and 135?m of cut-and-cover tunnels The contract also includes the design and construction of a new underground station including station entrances, subway links, architectural finishes and external landscaping. The station, located at Upper Bukit Timah Road near Jalan Jurong Kechil will also double as a civil defence shelter.The works included significant traffic management in a dense urban area in order to create the working areas whilst keeping the requisite number of traffic lanes. This involved numerous utility diversions and included the removal of a 33-year-old pedestrian overhead bridge (POB) over busy Bukit Timah Road. The station and tunnelling works were completed on time, including a ‘dock and dismantle’ TBM retrieval and subsequent breakthrough of the separating wall.This paper will detail the methods and solutions used to construct the tunnels and stations, with a focus on the requirements for construction of the station to be a civil defence shelter if required. This involved solutions to tying reinforcement and placing concrete to high standards in a restricted space, as well as the incorporation of heavy blast doors and other associated protective measures. The efforts of the management team resulted in the project being awarded first prize in the 2011 Land Transport Authority’s Annual Safety Award Convention and being named winner of the Safety and Health Award Recognition for Projects (SHARP) award at the 2011 Workplace Safety and Health (WSH) Awards. As well, McConnell Dowell won a Green and Gracious Builder Award (Excellent Category) from the Building and Construction Authority (BCA).CITATION:McDonough, R, 2014. Design and construction contract C916 Beauty World Station and Tunnels, Singapore, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 411–418 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By R H. Sillitoe

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Geological concepts are employed routinely in porphyry copper exploration at the area selection, prospect appraisal and deposit definition stages. Regional, district-scale, deposit-scale and laboratory-based concepts can all play a role, with the resulting porphyry copper models providing templates for the integration of geochemical and geophysical responses and interpretations. Of the 19 concepts and parameters selected for brief discussion, those relating to subdivision of porphyry intrusions, understanding of diverse and commonly complex alteration-mineralisation patterns and lithocap characterisation are undoubtedly the most influential in exploration. Several of them are of particular importance because of their role in promoting grade development. Additional belt-, district- and deposit-scale features are currently little used but hold promise, whereas others have less practical value but help in underpinning the evolving porphyry copper genetic model.CITATION:Sillitoe, R H, 2015. Recent advances in porphyry copper geology and their exploration utility , in Proceedings PACRIM 2015 Congress, pp 35–44 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

THE North Mount Lyell Mine is situated on the southern side of Mount Lyell at an altitude of 1750 ft. above sea-level. The average rainfall is 117 in., and there are generally several light falls of snow during the year. Despite the heavy rainfall, which is fairly evenly distributed over each of the twelve months, the climate is equable and not unduly rigorous, and, provided that the mine employee is suitably clad, it is only on exceptional days that he experiences any discomfort by becoming wet journeying to and from the mine.The majority of employes reside at Queenstown, and are conveyed by special trains to and from the top of the haulage, which is less than a mile from the mine. The mean surface temperature at the mine is 46° F., with a maximum variation from 26° F. to 85° F., the relative humidity generally being higher than in other districts. The rock temperature is 48° F. on the 200-ft. or Main Adit level, and 54° F, on the 1200-ft. level, giving a rise of 6° F. for 1000 ft. in depth.The ventilation of the mine is natural, the downcast being served by the Crown and Blocks shafts and the Crown mullock pass, and the upcast air is carried away from the workings by the Main shaft and the Nos. 1 and 2 mullock passes. The quantity of air circulating varies from 25,000 cub. ft. to 35,000 cub. ft. per minute, the greater quantity moving in the colder weather. The downcast air in traversing the wet shafts becomes saturated and enters the level at the rock temperature of 54° F. in winter and about 56° F. in summer, while temperature readings of the outcast air indicate that it varies very little.In the southern end of the mine the Blocks shaft downcast air upcasts through the different stopes, and their mullock passes, to the level above for each level to the 700-ft. level, where it passes to one of the main uptakes. The prown shaft downcast air supplies...

Jan 1, 1927

By S M Richardson, A W McNeill, J B. Gemmell

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Hellyer, Fossey, Que River and Mount Charter volcanic-hosted massive sulfide (VHMS) deposits occur within the Que-Hellyer volcanics of the Mount Read volcanics, Tasmania. These deposits occur along a 6 km strike length and are hosted by the same stratigraphic unit. We use a combination of whole-rock geochemistry, short wavelength infrared (SWIR) spectrometry, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analyses and compiled historic whole-rock geochemical data to develop district-scale vectors towards VHMS mineralisation.Strongly sericite and K-feldspar altered rocks concentrate along a linear trend from Hellyer, through Que River, to Mount Charter. Ishikawa alteration index values and whole-rock major and trace element concentrations provide exploration vectors towards mineralisation on a regional scale as significant enrichment and depletion trends. On a deposit scale, composition variations in white mica (sericite alteration), chlorite and K-feldspar are observed and reflected in whole-rock geochemical variations. Regional SWIR data from drill core support the prevalence of phengitic mica and high-Mg chlorite within footwall alteration halos and highlight the main upflow zones of hydrothermal fluids in the VHMS district. The combined use of regional whole-rock geochemistry, SWIR and mineral chemistry is an effective way to highlight prospective areas for VHMS mineralisation in a mature exploration province.CITATION:Wu, S, Gemmell, J B, McNeill, A W and Richardson, S M, 2015. Exploration implications from variations in whole-rock and mineral chemistry around the volcanic-hosted massive sulfide deposits of the Que-Hellyer volcanics, Tasmania, Australia , in Proceedings PACRIM 2015 Congress, pp 85–90 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By R Handfield, G Kary, Frieda Project

Recent exploration by the Cyprus Amax-Highlands Pacific-OMRD Joint Venture at the Frieda River project, PNG has demonstrated the extent of igneous phases, alteration and mineralisation, and the relationships between the various mineralisation styles in this major Cu-Au porphyry-epithermal system. The project area is in the obducted volcano-sedimentary section of the New Guinea mobile belt 78 km NE of Ok Tedi. It is between two major NNE dipping faults interpreted to have undergone thrusting then sinistral shear in the Late Miocene to Recent. The Frieda River Igneous Complex is a 15 km +7 km ovoid area with a central pod of basaltic andesite volcanics with cogenetic diorite to quartz diorite subvolcanic intrusions, and flanking clastic sediments. A series of late-stage, hornblende quartz diorite plugs ring the main igneous mass. The igneous rocks have a normal K calc-alkaline character with a very limited compositional variation. The intrusives are exposed on the eastern flank of the complex and have five mappable units and numerous defined phases. The southeastern quarter of the complex is host to a cluster of at least seven stockwork porphyry copper and skarn-hosted deposits within an area of 4.5 +3.5 km. The Horse-Ivaal and Koki deposits have identified resources totalling 804 mt @ 0.46 per cent Cu and 0.3 ppm Au, and the other deposits are in various stages of exploration. All these deposits are related to the Horse Microdiorite phase of the Complex and are outlined by a zone of potassic-propylitic-SCC alteration. Local overprinting argillic and advanced argillic alteration is related to a separate, post-porphyry mineralisation intrusive phase. The recent emphasis has been on the identification of higher-grade zones using ideas of structural control and specific intrusive-alteration-mineralisation relationships within the known resource areas. An elongate area 13 km x 4 km in the centre of the Complex has advanced argillic alteration in the volcanic rocks. This alteration zone hosts the Nena deposit (52.8 mt @ two per cent Cu and 0.7 ppm Au) and approximately 20 prospects of high sulphidation type. These deposits are distributed along two prominent NW-trending siliceous ridges interpreted as regional scale structures. Nena is a pod of vein and replacement sulphides hosted in a tectonically controlled multiphase breccia that overprints the advanced argillic alteration. The Nena deposit is 4 km from the nearest of the major porphyry occurrences. It is underlain by basemetal veins and minor porphyry mineralisation that are related to the Flimtem Trachyandesite intrusive phase. The recent search for additional Nena-type ore has focussed on the siliceous ridges using detailed structural and geochemical ore control criteria. Widespread, but poorly mineralised, basemetal-bearing carbonate and sulphate veins form a ring around the mineralised area. These veins have sericitic selvages, cut the porphyry mineralisation, but are cut by and locally underlie the silica-alunite phase of the advanced argillic alteration. The current model is that there are discrete intrusive phases responsible for each of major hydrothermal events at Frieda. These include from oldest to youngest:the Koki phase has no related alteration or mineralisation; the dominant Frieda phase has the hornfels, early skarn and minor magnetite-chalcopyrite mineralisation; the Horse phase has the bulk of porphyry copper and skarn-hosted mineralisation and minor basemetal veins; the peripheral Knob phase is barren; and the Flimtem phase has the high sulphidation epithermal deposits and minor porphyry and vein mineralisation. The intrusive phases span the interval 17 to 11.5 Ma and are co-magmatic. They represent discrete batches off the parent magma, rather than simple fractionation products.

Jan 1, 1999

By Johnson N. W

After an unsuccessful transfer from the laboratory to the pilot plant of galena flotation technology which used sodium metabisulphite and ethyl xanthate, laboratory flotation tests were conducted to identify any unusual variables which had a deleterious effect on the position of the lead rougher grade recovery curve for Hilton and Mount Isa silver-lead-zinc ores. Two variables (pulp temperature and contact time for ethyl xanthate and sodium metabisulphite) had important deleterious effects.The findings allowed a successful transfer of the laboratory process to a pilot plant scale process. The effect of temperature was important because the higher temperature (40°C) in the pilot plant pulp increased significantly the rate of reaction between ethyl xanthate and sodium metabisulphite. In the laboratory process at 20 to 25°C, the reaction rate was lower and did not interfere significantly with the process. The contact time for the two reagents was also important in the pilot plant scale process because of the higher reaction rate at 40°C.To employ ethyl xanthate in the pilot plant process, special precautions were required. Further, a collector (Aerofloat 241) from the dithiophosphate family was used successfully in the pilot plant process.

Jan 1, 1988

By E J. Hofmann, J E. Hofmann, A J. Hofmann-Fritz

"With its Head Quarters in Perth, global heavy engineering company Hofmann Engineering is one of the largest family owned engineering companies in Australia. The company has pioneered a number of new manufacturing processes and design improvements for components of large comminution equipment.Some of these innovations are: Innovative design improvements of high pressure grinding roll (HPGR) forged steel tyres. Hofmann Engineering has developed unique patented tungsten carbide stud and edge protection designs which improve wear life and introduce quick and cost effective replacement options to further extend the life of the tyre. Development of forged fabricated mill heads using rolled and welded high tensile steel plate as an alternative to cast conical mill heads. Establishment of Australian capability to manufacture and export up to 42 ft. (12.8 m) diameter SAG mill shells. Techniques for fast track, product improved replacements of cracked or damaged mill gears, including in situ profile & wear measurements of girth gears using portable coordinate measuring machine (CMM) technology, forged rim steel and induction hardening technology. Gear and pinion mechanical drive designs to 24 MW or higher for SAG mills of 38 ft. to 42 ft. (11.6 m - 12.8 m) diameter as reliable alternatives to gearless drives.The paper presents case studies from the Australian heavy manufacturing facilities of Hofmann Engineering on large, high powered equipment for both the domestic and export markets.CITATION:Hofmann, E J, Hofmann, J E and Hofmann-Fritz, A J, 2013. Australian innovations in high pressure grinding rolls and large grinding mill manufacture, in Proceedings MetPlant 2013, pp 141-151 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 15, 2013

By Cawte D. C, Just G. D, Whitchurch K. D

The stringent marketing specifications included in coal contracts mean that coal producers must supply cleaner and more consistent coal than may have been formerly required. Geostatistics has the potential to aid in the accurate estimation of the washability characteristics of coal. A prediction method, the Kriged Service Variable Approach has been developed.A Computer Aided Drafting and Design system has proved useful in the development and application of the approach. The geostatistical approach has been tested against coal geological and borehole data and applications discussed.

Jan 1, 1987