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The correct assessment and understanding of geotechnical conditions is fundamental to mine design and, hence, successful (safe and efficient) mine planning, design and operations. However, this assessment and understanding is simply not possible unless there is a sound appreciation of the geology of the project. This paper addresses geological uncertainty in mine engineering and its communication, and shows that a mining project that does not take geology properly into account in the engineering phase is fraught. Uncertainty levels become excessive, which leads to hazards and consequential risks in design and operations in terms of both safety and efficiency. Several examples, both positive and negative, are provided to make the point. The paper concludes that mining geologists must become more overtly cognisant of the influence of geology on mine engineering. Equally importantly, mining (and geotechnical) engineers must communicate better with their geological colleagues to ensure that they (the engineers) have a clear understating of the geological issues affecting their operations. The engineers must know how to ask the right questions of the geologists. Engineers who do not understand and take account of geology in their designs and operations are failing the expectations of stakeholders.

Jan 1, 2006

The T33-34 blast, the first major blast at Mount Isa Mines, broke 1,360,000 tonnes of copper ore using 349 tonnes of explosives. The original concept of firing T33, T34, T35 and U37 separately was changed during the life of the project due to adverse ground conditions. These conditions also caused the stoping method to be modified after the firing of the stopes had started. To stabilise the two stopes T33 and T34 where large fall off was occurring, rib pillars were left in the original slot. This caused the blast design to be more complex as these rib pillars had to "lead" the blast. The implication of such a large blast on the underground and surface environment was thoroughly investigated and precautions taken. The charging time of the blast was six weeks. Hook-up was started four days before the blast and continued until two hours prior to the blast. Detailed scheduling was carried out of other work that had to be done in the 24 hours before the blast to ensure that there were no delays in the firing.

Jan 1, 1977

Many problems occur in recruiting staff to remote mining operations, relating to both domestic and works environments. These are stated, together with steps which have been taken to overcome them. Geographical and climatic conditions applying to the Agnew mining operation are described. Company policies have been established to define criteria for selection of staff, and to define methods by which the criteria are applied.

Jan 1, 1980

A method is proposed for the analysis of tin in cassiterite ores. Tin is volatilised by heating with ammonium iodide. The tin iodide so formed is extracted with hydrochloric acid and the concentration is measured by atomic absorption spectroscopy using an air-hydrogen flame.It is considered that a more efficient extraction of tin and faster reproducible results are obtained than by any other known method.

Jan 1, 1967

A method of assessing the blastability of a rock mass is presented which makes use of five, readily available, simple parameters. These are the Rock Mass Description, Joint Plane Spacing, Joint Plane Orientation, Specific Gravity Influence and Hardness. For a particular rock mass a value is assigned to each parameter and the Blastability Index is calculated from these values. Application of the Index in blast planning and computer modelling is discussed.

Jan 1, 1986

Dealing with Aboriginals and various others purporting to represent them has become part and parcel of exploration and mining in Australia, whereas 20 years ago it was not. The author has been involved in dealings with Aboriginal groups over this period. The following paper is a summary of the social background to such dealings and a compendium of rules for the newcomer to this aspect of the resource industry.

Jan 1, 1990

A recently discovered high temperature (22G-2800°C) reaction between glycerol and the oxides and hydrous oxides of iron produces a green, well-crystalline complex glycerato-iron, whereas hydrous nickel oxides an) reduced by the glycerol to metallic nickel. When nickel isomorphously substitutes for iron within the goethite lattice this high temperature glyceration allows a separation of the two metals whereby the nickel can be extracted by solution techniques.

Jan 1, 1971

I propose to speak today about our mineral heritage. In common usage "heritage" refers to the past. It means the discoveries, the developments, the mines and the processing plants, the benefits, the consequences, and the human experiences flowing from these. The history of the industry, inseparable from the history of the countries in which The Institute operates, is a rich background of which we can all be proud.But there is also a much wider meaning to mineral heritage. Our past has left us with the ab\lity to create and operate world scale enterprises generating wealth for the community, the ability to offer satisfying and challenging careers in a wide range of skills to our young people, and the willingness to follow adventurous and challenging vocations in remote areas, away from the big cities, at a time when the mentality of many is to get the most for the least effort and at the least inconvenience to themselves. The industry continues to be the repository of the pioneer spirit and a vital contributor to improving the life of the people in our countries.Thus, while our mineral heritage has much to do with the past, an essential part of it is how we use this rich past to build and shape our future. It is in this broader context that I am speaking today.

Jan 1, 1990

By J Herbertson

æZero waste steel making productionÆ has already been the subject of several studies and also the successful result of some companies. Regarding waste and by-products, slags are the largest in terms of weight, although among the least hazardous. All steelmakers around the world are presently looking into profitable solutions, according to their local conditions: environment constraints, available markets, and mode of operation. Today the major technical methods of slag value capture include different levels of magnetic separation and screening to remove entrained steel, for production of aggregate in civil works. A survey of different retrieval processes shows that pyrometallurgical processing of steelmaking slags will increase the recovery ratio of iron and other metals. In the process, the remaining part of the material, a mixture of metallic oxides, can be easily transformed into hydraulic binder such as cement. Can steelmakers consider the slag as a co-product, and not only a waste or by-product? The ability of pyrometallurgical processes to treat other wastes and by-products generated in the steelplant is an opportunity for the steelmakers to reach the æzero waste productionÆ status. A technical survey of the experiences and possible solutions of pyrometallurgical processing is presented as well as technical descriptions of technological, economical and profitability analysis in relation with foreseeable markets.

Jan 1, 2002

THE following description of the surface plant of the Great Fitzroy Mines is to be understood as having been compiled by a mechanical engineer, who concerns himself more with the various appliances used, their correct construction to enable them to accomplish their prescribed work, and the production and transmission of the power required to operate them, than with the reasons for the physical and chemical processes which those appliances are called upon to assist in carrying out. Hence the metallurgist will not find herein more than the skeleton of the organism, which perhaps he would wish to be clothed with the detailed description of the substances undergoing treatment, in their various combinations, at all stages, and the results attained in separating the valuable constituents from the worthless. So, also, no details will be found of the methods employed by the management for. the purpose of determining by sampling and assaying the nature of the various products obtained.GENERALThe ore being worked at the Great Fitzroy Mine is divided into two classes :-1. Ore that requires concentration before smelting.2. Ore that can be smelted direct.Flow-sheet (Fig. 1) shows in outline the process of treatment to which ore of the first class is subjected, and the writer will endeavour to fill in that outline with some details of the appliances used.

Jan 1, 1911

By Schulz R. S, Staunton W. P, McGuire J

The increased activity in the Australian gold industry over the last decade has resulted in a concomitant increase in the use of sodium cyanide, with a projected consumption of 80,000 tonnes per annum by 1991. Growing environmental awareness by government, industry and the public has generated increased interest in the fate of cyanide near gold mine tailings dams and has highlighted the lack of basic knowledge in this area, particularly for Australian conditions.

Jan 1, 1991

It is argued that the capture of par- ticles by bubbles is primarily caused by hydrophobic ("structural") attraction forces. Neither dispersion forces nor double-layer forces can account for hydro- phobicity, though the latter are known to influence the kinetics of capture. The recent experiments of Israelachvili and Pashley (Nature, 300: 341-342, 1982) with hydrophobic mica plates provide the first measurements of the range and magni- tude of hydrophobic interaction forces.

Jan 1, 1984

A computer programming language known as GPSS is described and possible applications for the mining engineer are presented. The language is continually being upgraded with improved versions appearing about every three years. The tremendous power of the language is considered by comparing it with standard engineering programming languages, such as Fortran or Basic. Sample problems that can be solved using the language are indicated. The advantages and disadvantages of the languages are also discussed.

Jan 1, 1987

The developments in hydrocyclone classification in the milling circuit at Bougainville Copper Limited are discussed. A major change in cyclone size and improve- ments in operating conditions have been made. Test work has been carried out to assess the classification performance of a modified Linatex cyclone, Wemco cyclones and a two stage cycloning circuit. The use of a scalping cyclone, to remove coarse material from the present overflow product for regrind, has also been investigated.

Jan 1, 1978

By Morandini AF, Occella E, Clerici C, Mancini R

This contribution presents the first results of an experimental research aimed at finding an unified description of the first stages of a rock comminution process. With reference to the case of the jaw crushers and to the specific subject of the comminution law, the tests reviewed and analysed in this contribution have been carried out, at a laboratory scale, on five different materials (limestones, quartzite, serpentinite) at different reduction ratios and feed rates, and accurately recording both total power and idle running power. The analysis of the results has shown that: ò the grain size distribution of the products complies with a modified form of the Rosin-Rammler equation, already found to be well suited to representing the grain size distribution of blasted rock in previous works by the authors; ò observed trends of the consumed power at increasing reduction ratios is steeper than predicted by the classical Rittinger, Kick and Bond laws, Rittinger law representing however a closer approximation of the experimental results; and ò a more accurate description of the experimental results is provided by a modified form of the Rittinger law. Accuracy of the semi-empirical expression has been found to be usually better than ten per cent by comparing actual results with expected Results.

Jan 1, 1993

Past and present developments in the use of blast furnace slag in the manufacture of glass are outlined. The crude slag from Port Kembla is beneficiated by the Mineral Resources Division of Australian Consolidated Industries Ltd. at Mascot using a dry magnetic separation process which reduces the iron level in the slag to an acceptable value, The chemical and physical properties of both the crude and beneficiated slag are given and compared with those of other slags used in the manufacture of glass. Slag is added to intro- duce alumina into the glass and its addition to the glass batch also results in faster melting and refining. Slag was first used in Australia in 1968 and its use has increased steadily year by year. At present about 16 000 tonnes of slag are used per year, mainly in amber and white glass. Beneficiated slag is used'in three plants to supply all the alumina required in the amber glass and in four plants to supply part of the alumina required in the white glass, the amount added depending on the acceptable iron level in the glass. Slag is also used in limited quantities in the manufacture of both dark and light green glass.

Jan 1, 1979

Erratic, though spatially localised occurrences of gold particles are a common feature of high-nugget gold systems. In many cases, gold is present as isolated or clustered, often coarse particles. The nugget effect is a part consequence of small-scale geologically controlled enrichment, and the inclusion or exclusion of gold particles from samples. Economic zones are generally contained within discrete structurally-controlled ore shoots which are surrounded by, and may include barren to low-grade background material. Problems are often encountered where small sample types (eg drill core and channel samples) of a few kilograms mass understate in situ grade by up to a few orders of magnitude, due to their general inability to represent the true gold particle distribution. This leads to uncertainty in mineral resource estimates. This contribution presents case studies where geologically-based parameters have been collected from drill core and underground faces to support grade determination. These parameters - or proxies - are based on mineralogical and/or geochemical (eg specific elemental ratios, fluid inclusion compositions and elemental correlations) criteria. Such criteria can be correlated with different grade domains to provide an indication of true grade within a geologically-controlled context. Proxies have recently been used to support resource estimates reported in accordance with the JORC Code.

Mar 1, 2010

This paper describes a steam outburst in a metal mine which occurred in December 1992 in Japan, resulting in two fatalities. The outburst occurred just after blasting in a heading face 600 m below surface (SL-50 m), 1664 m from a mouth of the mine. The scale of the outburst was large and the fragments of the outburst spread up to 34 m from the face, the total volume of the outburst was estimated to be 206 m3. The outburst materials were mostly clay originated from the typical surrounding rock of sulfide ore and basalt. The shape of the larger outburst fragments were slabs with a thickness of 10 to 20 cm. The victims were found in a main ventilation air shaft, 175 m and 380 m from the face, respectively. The mine mainly produces copper, lead and zinc. The face was ventilated by a 560 mm diameter duct with a fan and the strata temperature of the rock was estimated to be in the range of 120 to 140¦C. There is a famous hot spring near the mine. A thorough investigation into the unprecedented accident was made including an on-site inspection and investigation of rock characteristics in laboratories.

Jan 1, 2005

By Smart RST C, Johnson NW, Ralston J, Griffin LF

At the Copper Concentrator of Mount Isa Mines, the largest diluent of the copper concentrate is liberated fine pyrite. Laboratory flotation tests carried out as a function of grind and flotation Eh in combination with surface analysis by X-ray photoelectron spectroscopy (XPS) have identified the major mechanisms of iron sulphide flotation. It was found that a significant proportion of the iron sulphide minerals had surface coverages of graphitic carbon, sufficient to impart moderate hydrophobicity in the absence of collector. A smaller, but economically significant proportion of chalcopyrite was also affected by the graphitic carbon coating. Two methods were tested to reduce the impact of the natural floatability of the iron sulphides on concentrate grades. 1. Depression through the use of organic depressants. 2. Preflotation to remove the "naturally hydrophobic" iron sulphides (flotation independant of Eh ) prior to chalcopyrite flotation. Preflotation was tested at the pilot plant scale. It was found that the amount of chalcopyrite reporting to the preflotation rougher concentrate could be minimised through flotation at a mildly reducing Eh by the use of nitrogen as the flotation gas to maintain the low Eh conditions resulting from grinding. The preflotation rougher concentrate was upgraded to an iron sulphide concentrate or a low grade copper concentrate.

Jan 1, 1991

Details are given of the excellent performance, outside Australia, of steel slag in road pavement surfacing. Laboratory tests and plant trials have shown Port Kembla BOF steel slag to be a material with properties suitable for producing asphaltic concrete which will maintain a high skid resistance in service under heavy traffic. The high density of steel slag is a factor which will result in a cartage cost penalty likely to restrict usage to close to its source.

Jan 1, 1979