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By Quinn P, Robertson G, Agar GE

The replacement of diphenylguanidine (DPG) for separating INCO Bessemer matte with a water soluble collector requires a frother since most collectors do not have frothing properties. The objective of this study was to identify a non persistent frother which produced a deep froth and collapsed rapidly, while maintaining acceptable metallurgical separation. Incremental rougher flotation tests failed to differentiate any metallurgical benefit through the use of a specific frother, so other tests were employed to identify the candidate frother. The equilibrium froth height and rate of froth collapse (froth stability) of several commercial frothers were evaluated as a function of frother concentration using a 'frothmeter' apparatus. Frothers evaluated were methyl isobutyl carbinol (MIBC), Pine Oil, triethoxy butane, Dowfroth SA1263, Dowfroth 250C, Dowfroth 200 and Allied Colloids CRNI-1002. Dowfroth SA1263 produced the largest froth height, and TEB had the greatest rate of froth collapse. Frothers with properties similar to Dowfroth SA1263 and Dowfroth 250 were rejected due to their persistent froths. TEB was rejected because it has a low flash point and Pine Oil could be a nuisance to add to a flotation column. Therefore, the preferred frothers were declared to be Dowfroth 200 or Allied Colloids CRNl-1002.

Jan 1, 1993

Geosynclines have been well studied for many years, but very little has been written about the concepts of sedimentary basins in spite of the vast amount of data available. They have been regarded, perhaps, as well- understood intuitively, and therefore not worthy of study. Many of the fundamental concepts of geology were developed during the 19th Century with the construction of coal mines, canals and railways. It was a happy chance that led railway engineers in the early days to think that trains could not climb any but the smallest gradient, so, in Britain at -least, numerous railway cuttings and tunnels were made. These exposed to view and study, in a better form than Nature usually provides, a great deal of interesting geology. Because of the lack of literature about the concepts of sedimentary basins, it is not possible to be sure what the early geologists thought. It seems that sedimentary basins were regarded as recording a history of subsidence during the early stages, when a transgressive sequence accumulated; and a history of uplift during the later stages, when a regressive sequence accumulated. It seemed axiomatic that the age of folding and faulting was younger than the rocks folded or Faulted.

Jan 1, 1987

Australia today is one of the leading countries in the fields associated with the mineral industry, an industry which accounts for over 50% of overseas income and revenue to government. This is no accident. In order to be competitive in what was recog- nised very early in the country's history as a highly profitable busi- ness, the Australian mineral industry (mining, extractive and refining metallurgy) has traditionally been very innovation con- scious, a characteristic which has been evident from the begin- ning of the industry or very nearly so: Australia's geographic isolation and the dispersion of the mineral industry over wide distances made an exchange of ideas difficult and often impossible. One needs only to look at the inaugural address given by Sir Henry Ayers, the first president of the then Australasian Insti- tute of Mining Engineers, in Adelaide on 4th April, 1892 (1) "There is probably no other pursuit which depends more on its productive development and profitable results than in the extent and application of the scientific and mechanical knowledge possessed and exercised by its manager." and "Having in view the value of the mining industry of Austral- asians, they should be urged to apply their best skill with all the scientific and mechanical knowledge obtainable to its future development."

Jan 1, 1988

By Bowmaker MD

Zinc and lead sulphide flotation con centrates containing from 0.02 to 0.20% Cd are roasted on an updraught sinter machine at the Cockle Creek Works of Sulphide Corp- oration Pty. Limited to provide sinter for simultaneous smelting of zinc and lead in an Imperial Smelting Furnace (I.S.F.). The major portion (about 85%) of cad- mium in concentrate feed to the Sinter Plant is eliminated with sinter fume and is rec- overed by weak acid leaching in the Cadmium Plant'followed by counter-current decantat- ion, ion exchange concentration, precipitat- ion of cadmium sponge and partial refining to caustic refined cadmium metal. Cadmium not eliminated during sintering is volatilised in the I.S.F. and subsequently recovered as zinc alloy by distillation in the zinc ref- ining columns of the Zinc Refluxer. The partially refined cadmium metal and cadmium- zinc alloy are blended as feed to the cadm- ium refining column where separation and recovery of cadmium is effected. Condensate from the column is further refined under caustic soda flux and cast into anode shapes. Production is 200 t.p.a. at 85% recovery of cadmium in concentrates. Emphasis is placed on changes from the practice described by Baker and Munro (1965) and upon operation

Jan 1, 1972

Cyanidation tests by bottle agitation were conducted on an oxidized lead-silver ore containing approximately 12% Pb and 500 g/t Ag. Over 60% of the silver was leached when the ore was ground to 100% passing 0.15mm, whereas 50-60% of the silver was leached when the ore was only ground to 100% passing 0.5mm. Slurry handling and dewatering at the fine grind size were very difficult due to the high clay content of the ore, however this problem was greatly reduced at the coar- ser grind size. The silver recovery at the fine grind size was very dependent on cyanide solution strength with stronger cyanide sol- utions (containing more than 0.1% NaCN) re- sulting in lower solution silver contents. This was thought to be due to the precipi- tation of leached silver by zinc, which was also leached from the ore by the higher cyanide levels. There was a critical zinc level in solution of approximately 1000ppm, above which the silver recovery fell markedly. Cyanide and lime consumptions for this ore were high (typically 5 kg/t and 40 kg/t respectively), hence the processing of this particular ore by cyanide leaching is un- economic at current silver prices.

Jan 1, 1987

By E Wan, K Stokes

Since 1978, the nickel concentrator at Leinster has been subject to continuous change. In 1971 a significant nickel sulphide deposit was discovered on Leinster Downs Station, within three years the extent of the deposit was determined. In 1978 the Agnew Mining Company began production of nickel concentrate from the Perseverance Mine and continued to do so until production ceased in 1986. In 1988 WMC purchased the mothballed project and began the first phase of many expansion initiatives. Milestones in the life of Leinster have included:open cut mining of the Perseverance orebody and the discovery of the RockyÆs Reward orebody, as well as the metallurgical challenges in treating each of these; underground mining at both Perseverance and RockyÆs Reward; construction and commissioning of the WMC grinding and flotation circuits; variations in the reagent schemes, including the introduction of æliquidÆ reagents; development of mill linings to reduce maintenance; circuit re-configuration and simplification; development of Harmony open cut; strategies for increasing throughput at the drier; and changes to tailings facilities to cope with increased throughput. This paper outlines the steps which have been required to expand the Leinster Nickel Concentrator from 650 000 tpa to 2.5 Mtpa and those steps which will be required in the future.

Jan 1, 2000

By Finch JA, Uribe-Salas A

The relationship between the process variables and hydrodynamics of a downflow concurrent column (Jameson cell) was investigated in both two and three-phase systems. Gas holdups from 10 to -60 per cent were obtained at gas rates up to 15 cm/s (STP), liquid (slurry) rates up to 25 cm/s, frother concentrations of 5 and 25 ppm, and slurry density (silica) up to 1.23 g/cm3 ina 3.8 cm diameter, 190 cm high column with a 0.5 cm diameter nozzle. Gas holdup decreases with feed rate and increases with gas rate, reaching a maximum (-60 per cent) at a gas rate to feed rate ratio of about one. Gas holdups were higher with slurry compared to water as feed. Stable operation was difficult to maintain at high gas rates especially with low frother dosage; operation was not possible without some frother. Instability was characterised by loss of pool level or formation of slugs. The slugs could move up or down or remain oscillatory. A quantitative relationship between the variables and gas holdup or onset of instability was not identified. Conductivity and pressure-based techniques were successfully tested on-line for estimation of gas holdup and to judge the state of operation (eg formation of slugs).

Jan 1, 1993

THOSE who dabble in m.ining are no exception to the general rule that persons who know a little of a subject are apt to think that they know all about it. Some colour may be lent to the belief that anyone may succeed in mining when we hear stories ofsuccessful diggers and others who have accidentally dropped on to something good through no foresight on their part; but we seldom hear the contra account of the far larger number who fail. Those who go more thoroughly into the subject, and take up mining as a profession, know very well that it is not one that can be carried out successfully by rule of thumb, but when they point this out to the public they are credited with trying to make it a closed profession; and outsiders are for ever trying to find out the 'trade secrets,' at the same time spurning the main one, which is hard study, experience, and the ability to apply their knowledge.The average mining man is not rich. When he amasses a fortune it is generally through speculation rather than professional work, thought no doubt his technical knowledge may have assisted him. However, making a fortune and running a mine are twodifferent things.

Jan 1, 1911

By Ritchie I

Copper minerals are often associated with gold ores. These create processing problems since cyanide solutions are not selective for gold alone. Copper minerals are also leached by cyanide, and typically each one per cent of `reactive' copper in the ore consumes about 30 kg t 1 cyanide. Once in solution, copper cyanide species create further processing problems as they adsorb onto carbon along with the dicyanoaurate ion. These problems make conventional cyanidation of gold ore uneconomic if the ore contains too much copper. As a result, methods of economically processing gold-copper ores are becoming of increasing importance.One of the more promising methods of treating these ores is by selective leaching of the gold by an ammoniacal cyanide solution, a method first described by Hunt in 1901. This method is already in commercial use in Mauritania, treating copper/gold tailings. In general terms, the addition of I - 2 g U1 ammonia to a standard cyanide leach solution causes a significant increase in gold extraction and decrease in copper extraction. However, early testwork on this system has concluded that the optimal leach conditions are critically dependent on ore composition, and the mechanism is not well understood, making predictions of best conditions impossible.

Jan 1, 1997

By A Ruotsalainen

Mining industry sees a comprehensive future in optimisation and process control. High resource utilisation is a starting platform when lower operational costs with higher rate of return are the target. Simulation is quickly penetrating the mining industry as a planning tool. A discrete event simulation helps to visualise the reality of a mine and the various mining processes, which typically include a fair degree of complexity. What-if scenarios can help to determine the impact of occurring changes to production. Understanding of critical points in the layout and resource allocation at an early stage can help to optimise the material flow. The obtained information may then be used as proposal or confirmation of the system applicability and economy. Simulation is a way to fine-tune and optimise the resources within. It helps to predict system sensitivity to various aspects. Although simulation today is used typically in a feasibility stage, there is an opportunity to continue using simulation for further process enhancement. In the future simulation will without doubt be used increasingly as a dynamic simulation and continuous improvement tool. This paper discusses the use of OptimineÖ simulation tool in resource optimisation. Some examples describe the way the tool operates and how it helps to view the technology, mine layout and operational data.

Jan 1, 2003

By Moorrees C

Carbonic acid leaching of crude iron-containing magnesia derived from Savage River magnesite yields a magnesium bicarbonate leachate with a substantial soluble iron concentration. The iron concentration depends upon the leaching conditions (particularly time, temperature and pulp density) but is generally in the range 0.005-0.5 g/litre. If this soluble iron is not removed prior to the precipitation of the magnesium as a hydrated carbonate, then this product will be contaminated by the iron, and will not yield a final product (high-purity magnesia) that meets specifications.The soluble iron content of the magnesium bicarbonate leachate can be reduced to an acceptable level by addition of solid aluminium sulphate either during carbonic acid, leaching of the crude calcine or to the clarified leachate. Chemical analysis and X-ray diffraction revealed that the iron is precipitated as an iron-containing hydrotalcite-type compound, [Mg6(Al,Fe)2(OH)16]CO3.4H2O. The actual composition of the precipitate depends on the amount of aluminium sulphate added and the precipitation technique used. Because precipitation of iron in this manner also results in reduced magnesium recovery from the leachates, It WIll be necessary to develop methods for recovering the magnesium component of the precipitates.

Jan 1, 1984

By P Gardner

The Kanowna Belle gold mine in Western Australia has reached a depth of 1000 m on the way to 1300 m. A feasibility study undertaken in 2006 identified the mining of E-Block as both technically and commercially feasible. One of the major risks identified in the study was the ventilation capacity, as the existing primary ventilation system would not support the production schedule for mining and a major system upgrade would be required. Failure to provide the necessary airflow would put the project at risk. A review of the airflow requirements and infrastructure options detailed in the feasibility study was undertaken to ensure that the assumptions and design were optimised. This review recommended a minimum airflow of 206 m3/s, but by acknowledging the necessary constraints imposed by mining at depth and re-engineering the mine layout to optimise the primary ventilation circuit, this requirement was reduced to 160 m3/s. This represents a 22 per cent reduction in airflow and a reduction in capital cost that will see mining at depth become economically feasible at Kanowna Belle. This paper discusses the processes that led to a redesign of the mining layout and highlights the importance of including the ventilation network in the optimisation process.

Jan 1, 2008

'Nothing happens until something is sold' This statement is not original - it is a necessary orientation for marketing industrial minerals. The most important single philosophy of marketing is that it recognises the consumer as the starting point. Production orientation is concerned with producing products that the customer might buy. Market orientation is concerned with finding the needs of the customer and how they can be satisfied. The difference between the two approaches can be recognised in company structures but the most tangible difference is in the approach by a company to selling and development. In other words, it is the market that decides what can be done with a mineral. The markets requirements dictate what mineral, what grade and what price will be paid. Therefore it follows that when pricing a product we should avoid taking the basic cost and arriving at a final selling price through a series of standard markups (unless government insists on it). We should start with the price the market can stand and work backwards to find out whether you have a profitable product or one that will fail because it is too dear. Naturally a thorough understanding of production costs is necessary particularly when marginal markets are concerned.

Jan 1, 1978

By A Singleton, J Busfield

World coal producers have been under constant pressure in recent years because of falling export prices arising from oversupply and the Asian slowdown. This has resulted in a dynamic market place, a sharpening of focus on bottom line costs and some rationalisation of participants. Productivity has increased dramatically as many inefficiencies, typical of the coal industry, have been eroded through workplace reform. This is true for the both open cut and underground sectors of the industry. At the same time, the technology of underground mining is undergoing dynamic change. Mine operators are implementing better exploration and planning tools and are also starting to make gains against chronically low equipment availability and utilisation. æStep-changeÆ improvements in output are imminent. As the statutory environment shifts to a æduty of careÆ regime, it is hoped that mine safety performance will improve, particularly with regard to fatalities. The focus of the paper is on the Australian coal sector, although references to international benchmarks are made. Despite environmental threats to the future of coal, it is concluded that the next ten years will see impressive performance results from underground coal mines which will assist coal to maintain its position as the preferred fuel of lowest cost.

Jan 1, 2000

By P Elliott, D Pershke

In a minerals processing context, sustainability is about using natural resources more efficiently to achieve maximum economic benefits with minimal environmental impacts. It embodies five overarching themes, which the paper will illustrate with practical examples from Australian minerals processing plants. These are:resource utilisation and materials efficiency,process waste reduction and enhancement of co-product values,reduction of water use and impacts,reduction of energy requirements and greenhouse gas emissions, andenhanced control of minor elements and toxic materials. Sustainability could be embedded profitably in minerals plant design in three dimensions: 1.technology,2.design, and3.operations. This presentation discusses a set of principles that could be applied to minerals processing technologies and provides an outline of sustainability assessment and opportunities evaluation tools. The application of the tools is illustrated through a case study by analysing a suite of nickel processing technology routes. The analysis reveals that current generation of nickel processing technologies do possess real potential to emerge as sustainability champions in integrated processing of nickel ores and concentrates, if they are designed, engineered, and operated for sustainability and adapted effectively to site specific constraints and opportunities. The paper will address data gaps and uncertainties regarding the impact of scaling up of pilot-plant performance, and provides strategies to overcome them.

Jan 1, 2006

By Miovski P, Hooft P. V

In the majority of recently commissioned gold mines granular activated carbon is used to adsorb gold from alkaline cyanide pulps or solutions. At the same time the carbon also adsorbs many other inorganic and organic species, most of which lower the activity of the carbon. Removal of these foulants is necessary before the carbon is reactivated and recycled. Standard practice for re- storing carbon activity involves high temperature treatment in a kiln - an apparently straightforward unit operation which is not always satisfactorily carried out. This paper presents the results of some fundamental work carried out on the thermal reactivation of carbon in a laboratory rotating pot kiln. The effects of temperature and steam addition on carbon activity were examined and compared with the activity of carbons obtained from a number of commercial kilns. Carbon was also reactivated using a small-scale Rintoul Furnace in which carbon was resistively heated by the direct passage of an alternating electric current. It was established that both elevated temperatures and the addition of steam to hot carbon generally enhanced its activity although peat-based extruded carbons responded a little differently to coconut shell types. Other measurements made included the weight loss and the hardness of carbons as a function of reactivation conditions.

Jan 1, 1987

By Henderson J

Iron ore samples selected from the Deepdale, Iron Prince and Mt. Newman ore bodies have been pelletised on a pilot scale plant and subsequently reduced under laboratory conditions by hydrogen or carbon monoxide. Pellets approximately 1 cm in diameter have been reduced by hydrogen over the temperature range 5000- 900¦C and the results examined by thermogravimetric, microscopic, electron probe and x-ray techniques. After an initial time delay it was found that up to 95% reduction the rate of reduction could be described by a transport con- trolled porous model, in which the effective diffusivities of hydrogen in theòpr¦duct layer and the reaction zone are filar. Independent measurements of effective diffusivity supported the values obtained from the reduction data. ve 95% reduction the rate decreased markedly due to the formation_of retained wustite or fayalite. Comparison with reduction by carbon monoxide over the temperature range 7500 - 900¦C showed that the rate eduction by carbon monoxide was approximately five times slower than the rate by hydrogen. The rate of reduction was found to be a function of the properties of the pellets, which may account for the ely conflicting results that have been obtained in previous investigation on porous pellets.

Jan 1, 1970

The Burra Burra Aline is in complexly folded Torrensian dolomites and limestones forming the faulted axial region of a major anti cling. The orebody mined was largely of secondary origin and confined between two faults, Kingston's on the west and Tinline's on the east. The orebody occurred at the junction between cherty dolomites and a clastic limestone with a large mass of marble breccia along its western margin. Secondary ore consisted of carbonates and oxides in the breccia and the ore bed and detrital copper minerals deposited. As part of a clastic breccia in sink holes and solution cavities in the dolpthites and ore beds.Primary sulphides occur disseminated in the marble breccia and in stratiform habit in the ore bed. Kingston's so-called 'Lode' may be mineralised marble breccia.The marble breccia appears to be of diapric or sedimentary origin and there is evidence to support a sedimentary origin for some 'of the copper sulphides. No igneous rocks have been discovered within 20 miles of the mine and any hydrothermal activities were probably at comparatively low temperature. The possibility of extensive stratiform and disseminated copper sulphide mineralisation in the marble breccia and ore bed requires testing by further drilling and geophysicalsurveys.

Jan 1, 1963

By M J. Nugus, S C. Dominy

Mesothermal lode-gold deposits often pose problems during sampling because of their complex and erratic gold grade distribution, and the presence of coarse gold. Effective sampling and sample preparation protocols must form the basis of any resource estimate at whatever stage a project is at. Design of a sampling regime must be based upon a thorough understanding of orebody mineralogy and geology. This should include consideration of gold particle size and distribution. The sample type, size and density employed must also be based on the underlying geology of the deposit. Choice of sample preparation procedure and assay type is of critical importance if fundamental sampling error and analytical errors are to be minimised. Traditional fire assays, using small charge sizes, consistently understate assays gained from large charge sizes and techniques such as screen fire assay and bulk leach extractable gold assay. The proportion of coarse gold within samples will have a profound effect on the requirements for sample preparation and assay method. The application of Gy sampling theory can help to reduce errors within the processing of samples of broken rock. Quality control/assurance of sampling regimes must also be critically assessed. The problems associated with sampling mesothermal lode-gold type deposits are presented as case studies from Western Australia and North America.

Jan 1, 2003

Structure is the most important control on the location of hematite deposits in the Hamersley Province in the Pilbara region of Western Australia. Unravelling the structural history of mineralised areas, however, is complex because the Province underwent three orogenic events, and three regional extension events followed the main episodes of compression. Steeply E to ENE dipping normal faults immediately predated deposition of the Beasley Quartzite of the lower Wyloo Group after the Ophthalmian Orogeny. Steeply NE and SW-S dipping normal faults predated deposition of the McGrath formation of the middle Wyloo Group, following the Panhandle Orogeny. The resulting interpreted rift was subsequently reactivated and tilted during the Capricorn Orogeny. Late NE trending normal faults are confined to the eastern half of the Province. High-grade hematite deposits occur in rocks that range from intensely folded (Mt Whaleback, Giles Mini) to rocks with less, or only little deformation (Paraburdoo, Channar), suggesting that folding had at best limited influence on ore genesis. In contrast, extensional normal faults are always associated with high-grade hematite deposits, and in particular faults that link the underlying dolomites of the Wittenoom Formation with the overlying iron formation, thus providing a pathway for mineralising alkaline fluids.

Jan 1, 2005