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By Prosser A. P

The conditions under which vanadium is rendered insoluble by silica in the alkali-roast process have been investigated starting with both slag and reagent-grade materials. The inert phase is a glass formed slowlyfrom soluble NaV03 produced at lower temperatures. It contains approximately 30 per cent V in a partly reduced state; iron is not a principal component. Some of the vanadium in the inert phase is slowly returned to a soluble form by heating in an oxidizing atmosphere below the temperature at which the glass is formed (750°C). As the reaction leading to the required, soluble form of vanadium is also slow between 600 and 750° optimization and control of the temperature profile and atmosphere in the furnace, and the residence time of the solids, are necessary to ensure high vanadium extraction during subsequent leaching.

Jan 1, 1976

By P Cooper

Continuous improvement using six sigma methodologies commonly follows the DMAIC methodology of define, measure, analyse, improve and control. A key requirement in the use of this approach is to ensure that data is trusted, validated and contextual. In today’s production environments it is common to find disparate technology comprising the system architecture and highly customised interfaces between the various technology layers. This complexity often leads to inaccurate data presented at the operations management layer or worse, data that is not trusted. Identifying defects and making corrective actions cannot be efficiently carried out unless trusteddata can be easily obtained with a production context. It is also common to find that disparate systems of this nature present information in multiple ways and through multiple presentation systems. This paper discusses how the use of web-based technologies in an integrated technology stack can aid the accessibility, accuracy and trust of data used in decision-making and also how a unified visualisation environment can lead to greater operator efficiency.

Jul 11, 2011

Few, if any, reliable thermodynamic data are available for the activity of tin oxide in slags. In this work, the activity of the oxide in silica saturated iron silicate slags has been measured at 1573 K using the equilibrium Sn (alloy) + Y2O2-SnO (slag).Slag and a Ag-Sn alloy were sealed in a zirconium oxide crucible to prevent the escape of volatile tin oxide, and the oxygen pressure at equilibrium measured in situ using the zirconium oxide as a solid electrolyte. Activity of tin was calculated from known data for the Ag-Sn system and activity of tin oxide calculated from free energy data. The results have been extrapolated to predict the industrially important distribution of tin and iron between Fe-Sn alloy and iron silicate based slags.

Jan 1, 1983

Mere recognition of the need for technic- ally strong human resources in the'extractive metallurgical industries has not prevented the decline in the education base for broad spec- trum metallurgists. The ability of chemical engineers to perform very effectively in many extractive metallurgical positions does not remove from the need for a general metallurgic- al education system. The intrusion of chemical engineers into extractive metallurgy is only symptomatic of the problems facing the minerals industry and its educators. The prospect of a career in the minerals base industries is unattractive to potential students by virtue of perceived inadequacies in the professional basis of the industry and ignorance of its sig- nificance to Australia's future, as assisted by excessive secrecy and a low profile public Image.

Jan 1, 1987

This paper describes the principle of cut-and-break rock excavation, in which rock is first undercut, and the undercut material is subsequently broken free by a wedging action. The current work on cut-and-break using the large rock cutting test rig at the Centre for Mining Technology and Equipment (CMTE) is outlined, and suggestions are made as to the potential advantages of cut-and-break roadheading, particularly in excavating short tunnels in hard rock in an urban environment.

Jan 1, 1993

By N Bennett

This paper examines the practical and economic benefits of using bulk emulsion explosives in underground development mining; compared to ANFO, ANFO derivatives and packaged explosives. The key economic benefit of bulk emulsion is the replacement of relatively high cost packaged explosives with a bulk product. Key practical benefits include water resistance, improved coupling of explosive, reduced toxic gas production, increased shock energy and improved manual handling through the use of bulk products. Each of the benefits is proven using a variety of measurements and field results in order to quantify them. Where possible, dollar values are determined so that the benefits can be shown to translate into savings for the mine operator. The results show that, despite the difference in price between ANFO and bulk emulsions, bulk emulsions are most capable of delivering the lowest total cost of blasting. The savings potential of the introduction of bulk emulsion systems can result in an improvement in drill and blast costs for a mine operator, or a significant increase in profit margin for a contract mining company.

Jan 1, 2007

During 1979 the writer had the privilege of interviewing about 50 people with varying degrees of involvement in the industrial arena and all of them in one way and another, had a part to play in the huge and intricate saga of Australian employee relations. They fell into the following' categories Industrial Relations Officers/Managers Academics Politicians Union Officials Representatives of Employer Associations Senior Industrialists Commission Members (State and Federal) Sundry (Journalists, Government Officials). This paper seeks to give an account of their views on various aspects of industrial relations. The interviews conducted were all on a personal and confidential basis so it can be expected that sources will not be identified. Suffice it to say that this account represents, albeit in "potted" form, the opinions of some of the most experienced individuals in the country. It will be seen that in most of the vital areas there is a remarkable lack of consensus. It should be noted that this lack of consensus existed within each of the groups mentioned.

Jan 1, 1980

In 1939 Dr Neil George gave us the statement: Safety is a state of mind by which men are constantly made aware of the possibility of injury at all times. Is this statement still relevant? Have we been able to capture the essence of Dr GeorgeÆs statement in our current safety management systems and have we been able to capture the lessons from the past? Drawing upon 25 years of experience in the mining industry we explore what was done in the past, how this related to Dr GeorgeÆs statement and how the industry has progressed to the current safety management systems. We review the safety management system used by Roche Mining and demonstrate how it has improved safety outcomes for Roche. We then look to the future û are there new challenges? Are the current management systems equipped to cater for these new challenges and deliver continued improvement in safety outcomes? There will always be a desire to improve the industryÆs safety outcomes and so how are future generations going to achieve the improvement in safety outcomes?

Jan 1, 2007

By D Brown, K Markovic

The world is becoming an increasingly complex environment to operate within. Adoption and evolution of technology is occurring at a rapid pace and operating spaces are growing in interconnectedness and interdependency. In mining this is evidenced by the large-scale adoption of autonomous machinery, intelligent systems, Internet of Things (IoT) devices, and robotics to realise benefits in optimisation, productivity, and safety. To enable continual delivery and growth in operational performance, and to realise the aforementioned benefits, a new approach for managing mining and metals is required (Mining Review Africa, 2023). This means that an already talent constrained workforce must learn to manage the complexity inherent, evolving, and growing in the environment (Abenov et al, 2023). A key skill that needs to be further developed and deployed to combat these challenges and to enable robust problem solving is that of systems thinking, which is already practiced in pockets within the mining industry. Experience and learning can be leveraged from other industries and their application of systems thinking to ensure that focus is maintained on areas where the benefits from which will be optimised. With targeted application, a workforce capable of effective systems thinking can be the catalyst to optimisation across mining organisations.

Sep 1, 2024

Dartbrook (Hunter Valley and South Bulli (Southern Coalfield) Collieries provide contrasting settings for gas sorption studies. Gas compositions at Dartbrook are dominated by carbon dioxide, with minor methane, while those at South Bulli are dominated by methane with minor carbon dioxide. Total gas contents at Dartbrook are also significantly greater than those at South Bulli. The two collieries are also contrasted in terms of coal composition and mining environment. Dartbrook Colliery mines a relatively small sectionb(4m) of very thick seam (up to mapproximately25m); the coal is vitrinite-rich, high volatile bituminous. South Bulli mines most of the seam thickness, with coal being an intertinite-rich, medium volatile bituminous coal.Coal samples have been collected from in-seam gas drainage holes for evaluation of relative gas desorption rate (methane versus carbon dioxide). Following adsorption isotherms, petrography, chemistry (proximate and ultimate analysis) and pore structure analysis (carbon dioxide surface area, mercury porosimetry). Bomb desorption studies indicate different behaviours for methane desorption at these two collieries desorbed gas compositions at South Bulli show a small enrichment in methane content. The opposite is observed at Dartbrook. Both collieries show enrichment in CO2 in the residual content. Adsorption studies show marked variation in adsorbed gas contents for methane and carbon dioxide at each colliery and between collieries. These variations are related to differences in coal pore structure, chemistry and Petrology.

Jan 1, 1998

By Morrison R. D, Davis J. J, Fraser B, Kojovic T

1991 saw the completion of a three-year $1.1 million research and development program in mineral sands beneficiation, funded in two associated projects by the Australian mineral sands industry through AMIRA, and carried out by the Julius Kruttschnitt Mineral Research Centre. It is believed to be the largest R&D project in mineral sands ever conducted by a university research group. It covered dry plant operation, and delivered several products to the industrial sponsors, including: ò A detailed characterisation of the radiation properties, mineralogy and size distribution of inhaleable dust arising in dry plants. ò New process models of magnetic and electrostatic separators. ò New on-line instruments for elemental assay (in association with AMDEL) and bulk conductivity measurements of dry process streams. ò Demonstration and evaluation of the Magstream magnetohydrostatic separation technology.

Jan 1, 1992

By E Widijanto, A Srikant

PT Freeport Indonesia operates a copper-gold mine located in the remote highlands of Papua, Indonesia, about 3500 km east of Jakarta. Currently, the district produces about 240 000 tonnes per day (tpd) of which about 45 000 tpd come from the DOZ Block Cave and the rest is mined from the Grasberg Open Pit. Over the next ten years, ore production from large block caves in the area is expected to reach about 200 000 tpd, replacing a large part of the production from the Grasberg Pit. Block cave mining alters the hydrological characteristics of the area being mined and when the cave expresses itself at the surface in the form of subsidence, it increases the entrapment area for surface water. Operating a large block cave mine in a region with an average annual rainfall of 5500 mm in steep mountainous terrain and complex geological and hydrological features presents a challenging scenario for dewatering or depressurisation of the area. The high rainfall infiltration and entrapment in stacked mines operating within an essentially single orebody, coupled with the presence of fine-grained and clayey material within the draw points of the block cave, creates mud rushes or wet muck spills, which can endanger the personnel and interrupt production. This paper outlines the problems caused by high water inflow into the DOZ Block Cave and the efforts undertaken to ensure the safety of the miners and continued achievement of desired production rates from underground mining in the district.

Jan 1, 2006

By D H. Laubscher

The in situ rock mass rating system û IRMR - leading to the mining rock mass rating system - MRMR - for jointed rock masses has been used (and abused) in mining operations around the world for the past 27 years. Despite the recent development of elaborate design procedures and computer-aided design packages, MRMR remains one of the most versatile and practical mine design systems available. It is important to realise that the rock mass classification system should not be replaced but rather complemented by more sophisticated and detailed design procedures. The classification system is not only the æcrudeÆ method used for initial assessment (as described in some geotechnical literature) but also in many respects a very effective and practical engineering tool. MRMR could, and should be used during the entire stage of mine life as an integral part of the design process. The objectives of this paper are to illustrate using practical case histories from the past decade, some of the pitfalls of the MRMR classification system, to clarify certain misconceptions in its application and update its mining application.

Jan 1, 2000

Continuous, steady-state laboratory flotation tests showed that the recovery of cha1copyrite from a naturally occurring ore, under conditions closely resembling those of plant practice, could be expressed in terms of a first order rate equation.Tests on full-scale plant flotation cells, using impulse tracers, indicated ideal mixing of the pulp in the cells.It was demonstrated that values of first order flotation rate constants can onlv be obtained from conventional methods of analysis in special cases.Analysis of a plant sampling campaign by the author supported a first order kinetic equation for two mineral species, and for the individual size fractions of one of these.The effect of stage-addition of reagents is interpreted in kinetic terms.

Jan 1, 1966

The extent of regional stratigraphic and structural geological mapping so far carried out in Australia is likely to be greatly overestimated by uncritical inspection of the latest authoritative geological map of the continent-that so ably compiled by the late Sir'T. W. Edgeworth David. Vast areas geologically coloured on this map are in fact known only from the most meagre field data, some of Which even include observations of distant views from which the so-called "geology" has been indicated in' reconnaissance reports.This applies to large areas in Cape York Peninsula; the plateau of Arnhem Land, and its margins except on the west where the Pine Creek mineral belt is better known; to the Desert Basin of Western Australia, practically the whole of the western half of the Northern Territory, much of east-central Western Australia, and northwestern New South Wales. Other vast areas are, more happily perhaps, left blank. It is true that prospecting parties have, at various times and with varying degrees of thoroughness, traversedparts of these little-known regions, often, however, in the search for gold or the.more obvious types of metalliferous mineral deposits and, furthermore, too often without leaving any written account of their examination, or with very sketchy details supplied. Unpublished geological surveys also cover some parts of these regions, but, on the whole, the picture we can draw of the regional deployment of rock masses in Australia is far less full than even David's map, with its obvious blanks, presents to us.Lest the practical mineral seeker among us should be inclined to place too much reliance on the prospecting to which I have referred.as giving him a straight hint of what country to keep out of, we may point to the recent discovery of a major sedimentary basin in the east KimberllilYs on which Dr. Teichert will have more to say. And that there are new metalliferous mineral deposits to be foundin parts of these little-known areas no one can doubt, for, after all, new discoveries are made from time to time in areas so well-known as the Victorian gold-fields. I take it then that regional geological mapping is a necessary concomitant of the further development of Australia's mineral resources-but I am not of the school that places it first on the list of priorities, and furthermore I believe that there can be a royal road to regional mapping-an inspired approach based on knowledge already gained and led to fruition by field surveys in key areas, by which there may be obtained a result giving a significantly close approach to actuality with only a fraction of the work that would be required for detailed field surveys on a systematic basis. I believe that a policy of rapid reconnaissance of such a type should be adhered to, especially in view of present deficiencies in numbers of geologists available for all purposes in Australia. The details that must eventually be sought can, I believe, be filled in later as the whole country becomes more developed and amenable to detailed surveys.

Jan 1, 1950

By Fuller P. G, Dugan K. J

Artificial support can be used to improve wall stability in open pit mines. This is examined for a particular case where the factor of safety for a slope is kept constant by using artificial support as the slope angle is increased. It is demonstrated that the savings in excavation generally exceed the cost of support. However, in order to correctly judge the eco- nomic impact of artificial support on the project, all the elements relat- ing to the use of artificial support must be taken in account.

Jan 1, 1989

By K Firmin

The Mt Tom Price orebody of Hamersley Iron Pty Limited consists of a folded hematite - shale sequence capped by a layer of goethite. Consequently, variations in iron content occur within the ore body, and as the overall grade is below that required to make specification products, selective mining must be carried out. A necessary preliminary to quality control of products based on selective mining is the production of advance data on the tonnages and grades of material to be expected in future mining areas. Bench plans showing zones of different grades and types of material anticipated are prepared from structural geological information. The grades of materials on a bench are essentially governed by the positions and attitudes of the shale bands. Quality control is exercised by blending different grades and types of material in primary crusher feed. Iron grade is the prime grade consideration although sometimes the level of phosphorus content must be considered. Pre-production grades are determined from assay of samples taken from blast hole cuttings. As shales are more friable than hematite, product fines are always lower in iron grade than the lump product. The realisation of contract specification grade is more difficult with fines than with lump, so maintaining the correct fines grade becomes a prime factor in quality control. Control of fines grade is presently effected by aiming for an appropriate feed grade to the primary stockpile. Studies to estimate fines grade directly by qualitatively taking into account material types are in progress. Quality control measures are checked by monitoring the crushing and screening plant output, and taking appropriate compensatory actions in the mine when required. Minor fluctuations in quality of fines can be blended out on stockpiles. The quality control measures described ensure constant quality products, and a good recovery of high grade material from the deposit.

Jan 1, 1971

By Lownds C. M

Several classes of commercial explosives and blasting agents behave non-ideally, especially in diameters near their critical diameter. A direct and convenient measure of non-ideal behavior is the detonation velocity (VOD); if the VOD is less than the ideal value, usually obtained by calculation, then the explosive is detonating in the non-ideal mode. Such lowering of the VOD is usually due to both lateral loss of energy and post-CJ release of energy. The second of these factors, namely slow release of chemical energy, is of most interest in blasting. While the observation of a low VOD clearly suggests slow reaction of part of the explosive composition, it does not necessarily mean that the energy is lost to the overall rock-breaking process. The partition of the energy of the explosive into various useful and wasteful categories is considered. Simple models of energy partition in blasting, and of explosive reaction kinetics, are presented. The models consider the effect of explosive type and rock type, the explosive being described in terms of the most common phases namely liquid, air bubbles, porous ammonium nitrate, dense or crystalline ammonium nitrate, and aluminum. Over a range of combinations of the above phases, the model predicts reasonable critical diameters and VOD's. Results are presented which show the effects of non-ideal detonation on fragmentation and heave in different rock types. Conclusions are drawn about those blasting conditions in which ideal behavior is beneficial, or Disadvantageous.

Jan 1, 1990

By Spark R. F

The copper deposits at Pernatty Lagoon are predominately djurleite-digenite bodies beneath the permanent water table, and chrysocolla-atacamite-malachite above the permanent water table. The minerals havebeen deposited as sheets, lobes, and pods in zones suggestive of permeability channels or permeability basius with respect to groundwater circulation.Pyrite is deposited in the form of framboids, which reflects its biogenic origin. Copper-iron sulphides deposit by replacement of pre-existent pyrite, and rarely by direct deposition. The latter mode of formation results in complex crustification bandings of chalcopyrite, bornite, sulphur rich bornites, digenite, and blue remaining covellites. The copper-iron sulphides appear to reequilibrate under constrained oxidation, resulting in an iron depletion and associated copper enrichment, the final product of which is a djurleite-digenite assemblage and associated with goethite. Where copper mineralization/ host rock relationships have rendered the rocks entirely impermeable to post ore groundwater movement, then the copper-iron sulphides are preserved as the ore assemblages.Minor and trace minerals observed include sphalerite, carrollite, galena, wittichenite, and possibly tetrahedrite in the primary ores. In the oxidized ores cllprite, tenorite, and trace brochantite have been found.

Jan 1, 1976

By Bevilacqua P, Preti U

The basic separation phenomena taking place in film concentration processes are studied through a kinetic-probabilistic approach. This approach is based on the fact that the particle velocity in the film separation phenomena is a random variable and may be defined by frequency distributions and probability laws. The approach requires: 1. development of probabilistic models for describing the behaviour of particles having different specific gravity and size along selected trajectories in the separating devices; 2. setting up an experimental procedure for determining the relevant frequency distribution curves at the exit of the separators for the particles mentioned above; 3. estimation of model parameters and model validation. In the paper, the model equations are given for the mass distribution of particles on the surface of separators, the mass distribution at the exits of shaking tables and the residence time distribution in channel type devices. The relation between residence time distribution and particle velocity distribution is derived. The test procedure has been defined and results are reported for the exit or residence time distribution in channels. A comparison between experimental and calculated frequency distributions is reported.

Jan 1, 1993