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Predictive chemical models facilitate the selection, design and assessment of aqueous chemical processes. The development of expertise in aqueous themochemistry has not matched the explosion in computer technology for modelling, which has placed pressure on the need for acquisition of skills to critically assess the appropriateness of the models produced. The 'blind faith' culture which appears to be developing must be arrested by appropriate programs at the tertiary level and professional development strategies in the minerals industry.

Jan 1, 1996

By Riches N, Harbort G

The Jameson flotation cell was developed jointly by Mount Isa Mines Limited and Professor GJ Jameson of the University of Newcastle. The cell has been used in a number of cleaning applications within Mount Isa Mines Limited. In 1989 Peko Mines tested the Jameson flotation cell at the Warrego concentrator to upgrade recleaner concentrate. 2 x 1.4 m diameter Jameson flotation cells were installed in 1990. This paper describes the testing, commissioning and operation of these Cells.

Jan 1, 1991

Activity-composition-temperature relations for both gold and nickel have been determined for the solid and liquid states of the gold-nickel system by the application of the Margules equations. These relations are in satisfactory agreement with activity measurements of nickel in the solid state, the observed phase boundaries of the system between 700 and 1725°K, as well as being consistent with data on the enthalpy of mixing.

Jan 1, 1971

The Lennard Shelf Operations owned by Western Metals Ltd evolved from the Cadjebut Zinc Lead Mine (BHP) in August 1994. Original production of 0.5 mtpa will rise to 2.0 mtpa at the end of 1998. Employees work a multiple of fly-in/fly-out (FIFO) rosters from the Kimberley region and the WA Capital. The three underground mines, treatment and services departments will employ approximately 300 people by the end of 1998. The expansion of the Lennard Shelf Operations as a remote mining location was based on a fresh look at management systems and employee rosters which were generated from many years of mining experience. This paper will endeavour to summarise these experiences and analyse some of their outcomes. Dealing with several mining methods, engineering difficulties, logistical problems and climate extremes, the Lennard Shelf Operations has managed social/employee issues with excellent results. Much time has been spent to get this correct for the Lennard ShelfÆs own set of circumstances. Employees and associated companies must expect continuing changes and improvement as Western Metals strives to continually improve its management systems and employee rosters.

Jan 1, 1998

This paper gives a first-hand account of what a graduate mining engineer can learn by visiting Atlas Copco in Sweden and gives reasons why all mining engineering students should apply for this excellent scholarship. It will also (attempt to) refute the authorÆs mine managerÆs claim that the trip was a huge junket.

Jan 1, 2006

By OÆBrien D. R

Up until June 1988, Mount Thorley Coal Handling and Preparation Plant disposed of tailings by two methods. Approximately half of the plant tailings was mechanically dewatered by solid bowl centrifuges mixed with plant reject and was subsequently disposed in mine overburden spoils; the remainder was pumped to tailings ponds. Both future mine planning and environmental constraints could not allow for the long term construction of more tailings ponds so, following evaluation of available dewatering technology, belt press filters were selected for the treatment of tailings in excess of the capacity of the existing solid bowl centrifuges. Commission of the four 2.5 metre wide belt press filters soon showed that marked differences in performance were experienced when treating different coal seams. Further analysis showed that the coal tailings from different seams were quite different in terms of clay mineralogy, and these differences could be correlated with varying degrees of filter performance. Poor filter performance was experienced with coal tailings rich in sodium montmorillinite clays. A number of variables were investigated including in-line mechanical mixing of flocculant and feed slurry, cation exchange reagents such as gypsum, and upstream addition of cationic flocculant. In order to achieve satisfactory performance on the worst tailings, a combination of all of the above was required. In this paper, the reasons for selection of belt press filters and the program of investigations and testwork required to arrive at satisfactory belt press filter performance for the treatment of troublesome bentonitic rich tailings are discussed.

Jan 1, 1989

Coal Mining Land Use on the southern coalfields often preceded other land uses. Over the past century overlying land use has altered significantly, particularly with water supply storage development, road system building, railways, pipelines, electricity reticulation schemes and general urban develop- ment. National Parks were declared over coal bearing lands. Little regard was paid to the coal under the land surface by land developers, Government instrumentalities, central planners and the Metropolitan Water, Sewerage and Drainage Board and others, and little value was placed on this valuable energy source. These bodies derived no benefit from the under- lying mineral. In these circumstances, mine operators and such surface land users were put into adversary roles. Mass sterilisation of coal resources resulted. The loss of reserves continues, although the problem has become better under- stood. An Energy Impact Statement (EIS) submission by all surface land developers has been proposed as a means to justify the impact of the development on the coal reserves Beneath.

Jan 1, 1979

By Q Zhou, Y Ma, J Zhu, R L. Frost, P Yuan

A series of organoclays with different surfactant arrangements were prepared by ion exchange. The resulting organoclays were investigated using a combination of characterisation techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric measurement (TG) and N2 adsorption-desorption. In the present study, the pores within the organoclays were discussed on the basis of the micro- structural parameters, including BET-N2 surface area, pore volume, pore size, surfactant loading and distribution. The results show that both BET-N2 surface area and pore volume decrease from low to high packing density of the surfactant as the average pore size increases. Two basic organoclay models were proposed for hexadecyltrimethyl- ammonium bromide (HDTMAB) modified montmorillonites: 1. the surfactant mainly occupied the clay interlayer, and2. both the clay interlayer space and external surface were modified by surfactant. This study demonstrates that the pore structure of the resulting organoclays has a significant influence on the sorption efficiency and mechanism of p-nitrophenol onto the organoclays.

Jan 1, 2008

Australian continental crust has accreted and consolidated by thirds: 1/3 during Archean time, 1/3 during Early to mid- Proterozoic time, and 1/3 during latest Precambrian to mostly Paleozoic time. The progression of orogenic systems and the crustal consolidations they represent seem not fundamentally different in basic orogenic processes from better known Mesozoic-Cenozoic examples in that accretionary, continental margin, collisional, and intraplate intracratonic inverted and/or reactivated systems are all recognizable in the tectonic evolution of Australia.

Jan 1, 1995

Australian continental crust has accreted and consolidated by thirds: 1/3 during Archean time, 1/3 during Early to mid-Proterozoic time, and 1/3 during latest Precambrian to mostly Paleozoic time. The progression of orogenic systems and the crustal consolidations they represent seem not fundamentally different in basic orogenic processes from better known Mesozoic-Cenozoic examples in that accretionary, continental margin, collisional, and intraplate intracratonic inverted and/or reactivated systems are all recognizable in the tectonic evolution ofAustralia.

Jan 1, 1995

Fluid inclusions and sulfur isotopic compositions were studied in a possible extension of the Toyoha polymetallic vein deposit. The objective of this work was to gain a better understanding of the ore depositional conditions, sources of ore constituents, and distribution of mineralizing fluid in the region. Fluid inclusions in sphalerite and quartz show that most homogenization temperatures range between 190¦ and 290¦C. Most salinities range from 0.0 to 3.4 wt per cent NaCl equiv. Sulfur isotopic compositions of ore minerals (pyrite, sphalerite and galena), determined by a conventional technique, range between 1.3 and 7.7 per mil. The mineralizing fluids were characterized by relatively low and various temperatures and low to moderate salinities compared to those at the southeast region of the main ore bodies (Izumo and Shinano veins) where rare elements such as tin, tungsten and indium occurred. Obtained temperatures and salinities were attributed to the mixing of hydrothermal fluids with groundwater. Sulfur isotopic data suggest sulfide sulfur was of magmatic origin. Isotopic temperatures, estimated from the isotopic fractionation factor between sphalerite and coexisting galena, are between 195¦ and 322¦C. The temperatures are only consistent with fluid inclusion homogenization temperatures in sphalerite or coexisting quartz when sphalerite was a honey-yellow coarse crystal lacking conspicuous colored growth bands. This suggests the detailed classification of mineral pairs growth textures will be necessary for precise in situ measurements to obtain reasonable eothermometric results.

Jan 1, 2002

By Middlebrook PD

The problems of education and research in the extractive metallurgy area are being tackled by the University of Melbourne through activities centring on the Department of Chemical Engineering. The establishment of the G.K. Williams Laboratory and the enhance- ment of the teaching of material relevant to extractive metallurgy in the Chemical Engineering course aim-at providing graduates and experienced researchers for the industry and at providing a strong research group carrying out industrially significant research in the area of pyrometallurgy.

Jan 1, 1986

About 11,000 tons of contaminated zinc flotation concentrate were available in the form of earth walls from dams used for atmospheric drying of the concentrate.Following successful laboratory tests this material was treated in a plant by crushing, grinding, and then flotation in a circuit consisting of roughing, scavenging, and two stages of cleaning. Reagents used were copper sulphate and a little butyl xanthate and frother. About 5,720 tons of zinc concentrate assaying 52· 3 per cent zinc were produced.

Jan 1, 1968

By Adhikari G. R, Raju N. M

The breaking of rock by explosives occurs so rapidly that the details of the phenomenon cannot he observed by the unaided eye. High resolution cameras and VCRs offer a means of slowing down the blasting action. A high resolution super video camera with digital zoom and a variable shutter speed was imported and used for the first time in India as a tool for blast optimisation studies at Malanjkhand Copper Project. Slow motion play-back revealed that the gases vented out through the fissures. The crest moved prior to the lower portion of the bench when initiated with detonating cord. The delay timing between the rows was not enough to provide sufficient relief and rock movement. This inadequate delay timing resulted in flyrock from the back rows. Stemming ejection was observed from practically all the holes. The muck profile was not satisfactory. A trial was carried out using 450 ms in hole delays and 25 nis surface delays. The front row holes were drilled based on the observations made from the laser profiling survey system. The video of the monitored blast showed that the rock started moving prior to the stemming ejection. It could be clearly seen that the entire block was completely initiated through the surface delays before the onset of the burden movement, thus eliminating any chance of misfires. Viewing blasts in high quality slow motion was useful to arrive at modified design parameters, resulting in uniform fragment size distribution and controlled rock movement.

Jan 1, 1995

In Mount Isa voltage and frequency fluctuations caused. by haulage shaft operation gave considerable difficulties with the initial application of Atomic Absorption Spectro-photometry.The methods used to stabilise the various units ' have been described.- Some other difficulties and the means used to eliminate or reduce them together with a-modified burner design are also discussed.

Jan 1, 1963

This paper discusses how the i-kon TM Digital Energy Control System may be deployed by miners of massive underground orebodies to deliver significant advantage in terms of safety, cost and environmental compliance. Digital Energy Control offers an exciting opportunity for mine operators to review their blasting and mining practice to gain the most advantage from this new technology.

Jan 1, 2000

Magnesium-rich olivine is used as an additive in LKABÆs iron ore pellets in order to improve the high-temperature properties of the finished products. Olivine is only added to the pellets that are manufactured for ironmaking in the blast furnace process. The olivine comes from Minelco/LKABÆs mine at Seqi in Greenland. This dunite complex of Archean age contains about 95 - 98 per cent olivine. The grain size is typically 1 - 3 mm but much larger euhedral olivine crystals are common in the porphyritic type. The serpentinisation is absent or weak. The most common minor minerals are chromite, chlorite, talc, phlogopite, amphibole and pyroxene. The crushed olivine is transported to LKABÆs pelletising plants in Northern Sweden. After grinding, small amounts of olivine are mixed with the magnetite concentrate. The concentrate is rolled into green balls, about 10 - 14 mm in diameter. The moist green balls are transferred into the pelletising machine where the maximum temperature is about 1250¦C. The residence time in the pelletising machine is about one hour. Olivine is used in order to get pellets with better high-temperature properties. This paper deals with the olivine alteration during the pelletising process and the behaviour of magnesium following the decomposition of magnetite. The reactions are quite complex in the pellets because the physico-chemical conditions vary considerably in the process from one process step to another, and in the pellet bed from the top to the bottom. Some olivine particles in the finished product show very slight alteration, some particles are completely decomposed. The formation of the iron-rich coronas around the olivine particles is the most typical alteration. In the finished pellets the magnesium is mainly distributed between the following phases: unaltered olivine, coronas, Mg/Fe-ferrite and silicate slag.

Jan 1, 2008

By L J. Reynolds

Gold mineralisation at the Globe Progress deposit is hosted by a geologically complex zone of shearing and brecciation, within a package of deformed metasediments. Mineralisation styles range from quartz breccias and lodes to sheared clay pug zones and disseminated sulfides. A review of the diamond drill core intersections through the deposit indicates that critical hanging wall and footwall contacts can be a combination of sharp or gradational; visual or non-visual boundaries. Approximately 60 per cent of mineralised contacts can be confidently identified visually, particularly where associated with veining, distinct brecciation or shearing, and high sulfide content. However, the gold grade and distribution of disseminated mineralisation can be extremely difficult to estimate visually, with implications for resource estimation and grade control when mining. Using observed drill hole geology and assays, a new geologically based model for the gold mineralisation has been constructed for the deposit to reflect the expected variability of the mineralisation contacts. This new model will constrain resource estimation and also serve to act as a predictive model when open pit mining commences. Nevertheless, careful grade control practices such as drilling, trenching and supervised extraction of ore will be required to maximise ore recovery and minimise dilution during open cut mining.

Jan 1, 2006

Wheal Gawler was Australia's first metal mine. This leader was followed by an army of other metalliferous underground mines and surface operations in Australia. As a mine it was not highly significant economically because its small total production of nearly pure galena had low multiplier effects on the economy of South Aus- tralia. Its importance lay in its symbolism: here was a silver-lead mine close to the new town of Adelaide posing the question of what other min- erals lay in the Mount Lofty ranges and in the fields beyond.

Jan 1, 1987

By Houchin MR, Jenkins DH

This paper examines the importance of processing to the properties and performance of high purity zirconia ceramics. Many of the principles discussed, however, apply to ceramic processing in general. For fabricated ceramic articles to display their wide range of high performance properties, they must be made fully dense. The precursor powder and postpowder processing requirements necessary to achieve full density in the fabricated body are discussed. Brittleness, the anathema of ceramics, can be overcome in zirconia by incorporation of toughening mechanisms. Transformation toughening and microcrack toughening and their origins in partially stabilized zirconia are reviewed.

Jan 1, 1989