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By Torrance AC

A joint research programme conducted by BHP Central Research Laboratories and Du Pont Wesfarmers Pty Ltd examined the effect of the size of cast primers on the run up and steady state detonation veloci- ties of ammonium nitrate based explosives as a function of blasthole diameter. Both continuous and point to point velocity of detonation meas- urement techniques were used. The field trials examined a number of the Du Pont HDP series of primers in conjunction with ANFO, emulsion and watergel explosives. Results indicate that the run up velocity of 187mm diameter ANFO charges is negligible using cast primers as small as 150g. owever, emulsion and watergel explosives did exhibit run up in both 187 and 311mm diameter blastholes, independent of the size of primer. This could last from 7 to 10 blasthole diameters.

Jan 1, 1988

n One of the most interesting and economically important developments which has .`taken place- in the Kalgoorlie Field over the past twenty .years is the proved penetration of ore into - caicò schist. which:has been established on the North Kalgurli Mine. 'This is quite extensive, both. laterally and ' in -depth, and has occasioned-,'" ccasioned ' " some madification.of geological thought In the search for additional ore sources:. .Ore has been mined in calc schist almost since the' first major: gold::discoveries-were made,. and the principal 'features of the various types of depos:itl are well covered in the literature ' of the field. ' However, occurrences in caic schist have not-been characterised by the same degree of continuity or frequency as the innumerable lode formations in- the more -favourable quartz dolerite, ' and there has been a tendencyAo regard,them as isolated and discontinuous ore bearing structures, occurring only under very special-- conditions. It is not intended-:to describe the whole' range of caic schist ore occurrences in this paper, but only major controlling structures, whose penetration therein has been definitely established, and in which an appreciable .amount.of,_ore.has, been and is still being. found.. . It is considered that -similar stiiictiires: may present a' major objective for future exploratory work in other parts of the field'.

Jan 1, 1964

Robe River Mining manages a large open pit iron ore mine in the Pilbara region of the North-West of Australia. The mine is managed for various joint venture participants.In July 1986, Robe River Mining made various changes to its management philosophy, which were heavily publicised in the media at the time.As a result of those changes to its management philosophy, Robe River Mining has been able to dramatically increase its production output, productivity, and safety performance without having to resort to major capital outlays and without the benefit of restructuring of applicable industrial awards.

Jan 1, 1992

Industry can achieve best results via thorough planning, consultatiion with agencies and local communities and a 'hands on' approach to' environmental problem solvingThe Department of Energy and Minerals, through its Minerals Group, has regulatory responsibility for the mining and extractive industries in Victoria. The role of the group is to facilitate the environmentally responsible development of these industries for the benefit of Victorians. It has a wide range of contacts with other government agencies, local government and community groups.The paper is in three parts; firstly, an overview of the nature and contribution of the mining and extractive industries in Victoria; secondly, the industries' regulatory framework; and thirdly, the environmental issues facing the industries and the management of these issues.

Jan 1, 1992

By A Crawford, P Manton

Telfer is a gold/copper operation, currently operating one open pit mine and one underground mine. The ore processing plant consists of two parallel trains involving semi-autogenous mill, ball mill and crusher (SABC) grinding, flotation and leaching. Due to receiving relatively high grade underground ore for over half of its total feed, Train 1 frequently experienced cleaning circuit overloading during high production periods. This resulted in losses in recovery and ineffective concentrate upgrade. As a quick and simple solution, the Train 1 copper flotation circuit was reconfigured to send concentrate from the first two rougher cells directly to the final concentrate and return the cleaner scavenger tailings to the third rougher cell. These modifications have resulted in a 1.4 per cent increase in plant copper recovery with no change in final concentrate grade. Preliminary results also indicate gold recovery has increased by more than 1 per cent since the circuit reconfiguration. Other benefits include less spillage, more friendly circuit to operate and a more consistent metallurgical performance. Focus for the next phase of optimisation is on concentrate upgrade. A number of opportunities have been identified and are currently being investigated, including staged reagent addition, single stage cleaning of the first two copper rougher concentrates, regrinding of the remaining copper rougher concentrate prior to cleaning and process control based on a machine vision system.

Jan 1, 2009

By Jimbo I, Ogawa O

A series of experiments was carried out to investigate the solubilities of copper, arsenic, antimony and bismuth in silica-saturated iron silicate slags under controlled oxygen partial pressures at 1200 and 1250¦C. Molten copper containing each of the above elements was kept in contact with a slag in a silica crucible for 24 or 48 hours to attain equilibrium. No me- chanical entrapment of metal into the slag was observed. The appearance of the magnetite phase in the slag was avoided by holding oxygen potentials at substantially lower values than that evaluated from available data on iron silicate slags. Solubilities of copper, arsenic, antimony and bismuth in slags were plotted against oxy- gen potentials and both oxidic and atomic types of dissolution were found, except in the case of arsenic, from the dependencies of the solubili- ties on the oxygen potential and from positive intercepts of regression lines when extra- polated to zero oxygen potential. The dissolu- tion of arsenic seemed mostly oxidic. Distri- bution coefficients of arseò,ic, antimony and bismuth between copper and slag are also Discussed.

Jan 1, 1980

There have been many developments in recent years in pipeline transport to enable them to be more widely used in industry. Substantial tonnages of materials that are not affected by water, such as coal and other minerals, aggregates and wastes, can be moved over considerable distances in quite small diameter pipes. Where there are no existing road or rail facilities, long-distance pipelines are usually cheaper to install, and this advantage increases in difficult terrain. Pipeline operators all over the world assert that hydraulic lines pay for themselves in a relatively short time, in spite of the heavy capital outlay, and this is equally true for lines convey-ing slurries or pastes within a plant complex.'This paper reviews some of the more important investigations in the hydraulic transport field. Although reference to systems carrying a wide range of materials is made, the majority of recent published data centres on coal transport.The paper looks at the application to a wide range of particle sizes, the development of non-aqueous slurrying media and coal/water fuels. The review also looks at some of the equipment being proposed to provide more reliable operation and in particular the range of solids-handling pumps now available.-The paper goes on to identify areas where further research and development is required and some of the many organisations undertaking this work.

Jan 1, 1985

Until 1937, the mining of ore was carried out by conventional methods, using pneumatic drills and standard drill steel. The adoption of the diamond drill, formerly used for exploration work, for blast hole drilling in stopes, was first developed by Noranda Mines Limited, Noranda, Quebec, although it had been used previously in Northern Ontario and Western United States, to remove weak pillars and ore remnants left by conventional methods. Previous to the adoption of the diamond drill method at Noranda, a sub-level benching system of stoping was used. Sub-levels were driven at 35 ft. intervals and the benches drilled off by pneumatic drills using sectional steel. Results were very satisfactory, in sulphide ore, where the drilling was comparatively easy, but in the harder rhyolitestopes the footage drilled per machine-shift was only half of that obtained in the sulphide stopes, and owing to the high gauge loss, there was often difficulty in drilling holes to the required depth. This led to trials with the diamond drill for this type of work. While the cost per foot was more than with sectional steel, an appreciable saving in development work could be made by increasing the sublevel interval from 35 ft. to 60 ft., and stope widths from 60 to 100 ft. This saving, together with the increase in blasting efficiency, resulted in a substantial reduction in overall costs.CONDITIONS FOR SUCCESSFUL APPLICATIONWhile long diamond drill blast-hole mining has widespread application, there are certain conditions which appear to be desirable, if not absolutely necessary, for its successful use.

Jan 1, 1946

Western Mining Corporation (WMC), managers of the Windarra Nickel Project, installed a raise-bored haulage shaft and underground crushing system at the Mt Windarra Nickel Mine in 1982. The system is the second of its type installed by WMC, the first being at the Otter Juan Mine in Kambalda in 1976/77. Both haulage systems became necessary as a result of the increasing production limitations, and escalating costs of a deep decline mine.The Windarra haulage system required a single 3 m diameter vertical raise drill hole, 470 m deep and equipped for skip haulage. Two five tonne skips, in balance, hoist crushed ore and mullock to the surface, at a design rate of 200 tonne/hr, effectively reducing truck haulage leads by up to 50 per cent. The system is now fully operational and will enable the mine to achieve its maximum production rate.The raise-bored shaft system has been shown to be cost effective and would be used again in circumstances where raise drilling is applicable.

Jan 1, 1984

The first difficulty encount.ered in preparing this paper was to find a definition of the word "special" as applied to steel. The first thought is "obviously any grade not mild steel" but this is an over-simplification, because the term "mild steel" covers a series of carbon ranges, each found from experience to be especially suited to the production of a particular rolled section.Even if the Australian structural mild steels are excluded it is found that no part of the plant here is independent of special steel.The face-man on Iron Monarch makes his bench safe by barring down with a 0.6% carbon steel bar. He bores a hole into the ironstone with a 0.75-0.8% carbon steel drill, driven by a jackhammer which is built of a variety of special steels. After it is shot down, the stone is lifted by an electric shovel, very few of whose steel components fall into the general category of structural grades of mild steel.Further special steels are met with in the truck into which the stone is loaded, the hauling electric locomotive, and the rails on which these .run. Even the permanent way uses more than one grade, e.g., the crossings experiencing heavy service have their frogs built with austenitic manganese steel inserts.Special steels play their part in the overhead crane which tips these trucks, and in the crushers into which they discharge, and so they can be followed right through the production line, and they are still there at the seaward end of the ship loading boom at the head of the WhyalIa ore jetty.

Jan 1, 1951

The Ausmelt Catalytic Waste Converter (CWC) has been developed for use in the treatment of industrial wastes and for the recycling of secondary materials. Ausmelt Technology uses a top submerged lance system within a versatile and efficient slag bath reactor. High temperature pyrometallurgical reactions are carefully controlled within an oxidised molten siliceous slag such that metals can be extracted from waste feedstock for recycling, with non-volatile elements reporting to the slag, usually as oxides. Modification of the slag chemistry results in a final slag product that is stable, vitrified and is able to pass standard leach tests such that it is safe to discard or be used in civil engineering applications. Toxic components in the wastes such as organohalides can be completely destroyed and are prevented from reforming. Waste to energy conversion is practiced by the addition of a heat exchanger/steam generator in the converter offgas system. The Ausmelt CWC has been used for recovering zinc from residues and slags, treating spent potliner (SPL) from the aluminium industry and a wide range of electronic and other potentially valuable waste materials. Methods of monitoring the exhaust gases at different stages in the CWC gas handling system are discussed. The assay of these gases prior to emission is used to assist in the control of the converter chemistry to ensure the complete oxidative breakdown of the feedstock.

Jan 1, 2002

By I Mason, A Bray, K Smith, T Sindle

Borehole radar is a proven geophysical technology that can be used to map an orebody ahead of mining. This paper will present a case study, where borehole radar is being used within the mining cycle to map out orebody blocks, both as a strategic and tactical tool. Refined equipment and procedures now enables a slimline borehole radar tool to be deployed on the end of drill rods, making it easier and faster to deploy in an underground mine with minimal impact on the mining process. Boreholes are drilled in advance of mining; cover holes to ensure the competence of the hanging wall and geology holes to determine the location and grade of ore are two such examples. All of these boreholes can be entered using a borehole radar tool to map geology and structure ahead. The radar data can provide images of the orebody as well as help detect potential water bearing structures that could impact on safety at a mining face.

Jan 1, 2009

Silver and gold bearing ore from the Palmarejo mine, located within the Mexican state of Chihuahua, contains a complex mix of electrum, native silver, silver sulfides and silver chlorides. This paper presents a case study that describes the selection, development and engineering of a tailored process plant for the recovery of silver and gold from this ore. Process circuit feasibility study modelling, metallurgical test work and engineering studies are outlined. Options considered to optimise the recovery of the contained silver and gold are compared, based upon cost, operability, recovery and engineering aspects. Concentration by flotation was found to be the preferred primary recovery route. Intensive leaching of the flotation concentrate resulted in solution grades sufficient to allow direct electrowinning to be evaluated against the more traditional Merrill Crowe process. The flotation tailings stream is processed through a separate leaching stage as there is sufficient economic metal extractable from this stream. The processing flow sheet, which is designed to maximise the recovery from both the flotation concentrate and tailings, and to utilise a common metal production facility, is presented.

Jan 1, 2009

Drill and blast operations account for 12 - 15 per cent of total mining costs. This paper looks at a comparison between electronic detonators and non-electric detonators, focusing on the cost benefits associated with the high precision of the timing sequences of electronic detonators. An analysis of the total mining costs was made on two main case studies; one on a quarry in South Australia (Martin, 2007) and the other on a project undertaken at Sunrise Dam (Vaughan et al, 2007). The criteria used in the analysis included; the resulting fragmentation, a vibration analysis, crusher throughput and productivity analysis such as excavator cycle times, dig rates of the excavator and bucket fill factor. The results indicate that there were consistent production improvements and hence reductions in total mining costs attributed to the use of electric detonators. An increase in the degree of fragmentation gives lower crushing costs as more material passes through as undersize. This reduces truck delay time at the crusher, which in turn gives higher truck and shovels productivity as well as higher dig rates for the excavators.

Jan 1, 2008

It should be noted that with the passage of time all aspects of the mineral extraction process are becoming more sophisticated and complex. In order to deal with this, the education system should be geared to this continual technological advance.A new scheme is designed to attract high quality school leaven to take up courses serving the mineral industry. After graduation these students will play an important role in the areas of research and development which is essential for the growth of the Australian mining industry.

Jan 1, 1991

The issue of fine coal and tailings dewatering has become of increasing concern to many coal preparation operators, both in Australia and overseas due to a variety of factors. Increasing mechanisation and mining of thinner seams over the past decades has resulted in an increasing amount of fines generation while increasing international trade in coal and tighter environmental constraints on tailings disposal have resulted in the production of these same fines to be an increasing problem. However, technology to date has not always been able to supply a cost-effective solution to the handling of these fines in an efficient and environmentally benign manner. This paper will review the key issues associated with the dewatering of fine coal and tailings, will describe the major current practices and constraints, and finally will indicate alternative technologies that may have to be considered in the near future. For the purpose of this paper, "fine" coal is described as that material less than 0.5 mm in diameter (as this is the most common cutpoint between various plant circuits in Australian practice), although the technological constraints are very much dependent upon the fraction less than 45 micron. The amount of minus 0.5 mm material fed to plants varies, depending upon the type of coal and mining operation, but in Australia may range from less than ten per cent to greater than 30 per cent of the feed in higher rank coals.

Jan 1, 1991

Silica-Kaolin Sand Wet Sizing The Bulgarian deposits of silica-kaolin sand are localised in the eastern part of the Danube plain. After wet separation the raw material yields two products - washed kaolin (different grades) and silica sand (different grades). The water washing technology includes: disintegration; spiral classification; hydrocyclone classification and dewatering of kaolin grades; hydroclassification; sizing using drum screens and dewatering of silica sand grades. Research and development program has started to improve the silica-kaolin sand separation in processing plants. Based on the raw material and tails characterisation data and the preliminary experiments using Derrick Stacksizer screening machines a silica-kaolin sand wet sizing technology was developed. The full-scale pilot flowsheet includes the following units: Derrick Stacksizer equipped with 0.43 mm opening Derrick Urethane Panel; 500 mm Flat bottom Hydrocyclone; Derrick Stacksizer equipped with 0.150 mm opening Derrick Urethane Panel; 100 mm Hydrocyclone and Derrick Dual Motor Linear Motion Machine equipped with 0.064 mm opening Derrick Pyramid Panel. The pilot-test data clearly demonstrate that the new silica-kaolin sand wet sizing technology is suitable for Bulgarian silica-kaolin raw material. There are possibilities to increase the silica sand recovery increasing the production of silica sand grade PK 0.16 and starting the production a new grade PK 0.10.

Sep 13, 2010

By Penney B. K, Baghdadi A. A

An electron probe micro-analyser, controlled by a dedicated mini-computer,has been operating at Imperial College since 1970. The data assessment capability of the computer was limited and, in order to make better use of the information produced by the analyser, extra computing facilities were needed. Following the initiation of a Laboratory Automation Project at Imperial College involving the use of a central computer linked to laboratory type computers and to further more powerful systems,it became possible to carry out much more detailed and extensive mineralogical analyses by connecting the mini -computer to the Laboratory Automation Network. The paper describes the techniques employed including hardware, software, inter- connection, analysis and operating methods.

Jan 1, 1977

By Mahoney M

For gas content analysis in recent years, it has been standard procedure to report results on a 'dry ash free' (daf) basis, under the assumption that gas only adsorbs onto coaly material. In order to test the relationship between ash and sas content, samples of various rock types were taken from two drillholes in the Newcastle Coalfield. The results of this study confirmed the correlation between gas content and ash, providing an accurate means of relating gas contents for all carbonaceous rock types.

Jan 1, 1995

By D E. Langberg, D R. Swinbourne

The past century has seen the development and commercialisation of many new pyrometallurgical processes based on gas injection. The driving force behind this trend in smelting and refining technology was the increased productivity and resulting increase in capital utilisation achievable. However, measurement of system variables is not easy and their effect on the rate of the reactions involved is not well characterised. One of the critical parameters is the gas-liquid interfacial area produced by gas injection. Related variables such as bubble size and velocity, and gas hold-up fractions in aqueous systems have been measured using combinations of physical (visual, audio and electrical) and chemical techniques. Models have been developed relating interfacial area to physical properties and operating variables and attempts made to extrapolate these to high temperature, liquid metal systems. The only attempts at validation of these models have used either low temperature liquid metals, such as mercury or WoodÆs Metal, or operating plant data. This paper reviews existing knowledge of the effects of system variables on total interfacial area in gas injection systems. Interfacial area is calculated from a range of published experimental aqueous and liquid metal systems and used to assess existing models. An operating region diagram was developed to assess dynamic similarity between experimental and industrial systems. It highlights areas where further research into both measurement techniques and experimental system variables is required in order to extend knowledge and guide further technical and design advances into the 21st century.

Jan 1, 2000