The Hamersley Yandi Iron Ore Mine of Hamersley Iron Pty. Ltd. is located in the Pilbara region, Western Australia, approximately 90km north west of the town of Newman. The iron ore has accumulated in a palaeochannel as an enriched Channel Iron Deposit (CID). Mining in other parts of this palaeochannel has been practised since 1991. Named deposits in the province are, from west to east, Munjina, Pool, Meander, Western, Central, Eastern, Junction and the Billiard deposits.Presently the CID acts as an aquifer and transmits water through its fracture system. It is the main conduit for the regional groundwater. The Water and Rivers Commission of Western Australia considers the groundwater in the alluvial beds of the Weeli Wolli Creek overlying the CID to be a useful resource. The groundwater is currently used for stock watering so the quality should be preserved.Part of the four possible closure plans of the Yandi Mine is to backfill the excavated channel with waste rock from the mining operation. The waste material will consist of the uneconomic grade lateritic pisolite iron ore, together with colluvium and alluvium overburden. The closure plans will also leave behind two pit lakes.The impact of these closure plans vary but each plan will leave pit lakes containing water with high salinity and this may adversely affect the quality of the groundwater downstream of the lakes.The hydraulic conductivity of the shallow aquifer may be impaired by swelling clays found in parts of the waste material. This impact would be reduced if the chosen closure plan was one with hydrogeological flow management.The water quality downstream of the pit lakes will change and the environmental impact on the groundwater will depend on which closure plan is chosen. This thesis suggests a number of options for consideration.

Ok Tedi Mining Limited generates a copper and gold concentrate from its porphyry and skarn ore deposits located at Mt. Fublian, Western Province, PNG. The predominant porphyry ore-type is blended with high grade skarn ores to optimize copper and gold feed grades to the concentrator. Current operation (2003) is to blend 80% porphyry with 20% skarn ores, resulting in an acceptable concentrate grade and recovery. However, when the proportion of skarn ore in the plant feed exceeds 20%, low flotation recovery is often observed. Approximately 20% of the copper and 30% gold losses occur through the rougher flotation circuit. However, losses via the cleaner tailing stream are 8% and 9% for copper and gold, respectively, and augment value mineral losses to the final tailing. It may be noted that the cleaner tailing stream contains value minerals which have already been successfully floated in the rougher section of the concentrator, and are therefore recoverable. This study has the objective of determining the reasons for copper and gold loss in the cleaner tailing. The focus is therefore on the cleaner flotation bank and related streams. The project strategy commenced with characterization of the cleaner circuit performance under various operating conditions. This would provide evidence for any proposed mechanisms to explain the losses of valuable minerals to the cleaner tailing. The second part of the project strategy was to evaluate potential methods for improvement of cleaner flotation performance via laboratory flotation tests. To complete the work, plant trials of methods showing benefit in the laboratory were conducted. / Characterisation surveys of the cleaner flotation bank were conducted as a function of ore blend, pulp and surface chemistry, mineralogy, flotation kinetics, particle size distribution, cleaner flotation cell hydrodynamic characterisation and residence time. These studies indicated that for greater than 20% pyrite skarn in the concentrator feed blend, lower than expected gold and copper recoveries were achieved in the cleaner bank. Pulp and surface chemical analytical techniques indicated layers of oxide coatings existed on all particles, depressing flotation. Oxide coatings had also resulted in the copper activation of pyrite (CuS rimming), making separation from copper sulfides difficult. Losses included coarse composite particles, also suggesting possible liberation issues. However, liberated copper sulfides were also lost, supporting the notion of depression via oxide coatings. Residence time calculations for the cleaner flotation bank suggested that the flotation capacity was less than adequate, particularly at high mill throughput rates. Hydrodynamic characterisation indicated improvements in cell hydrodynamics were warranted. In contrast to the oxidised ore feed blend described above, when less than 20% pyrite skarn was contained in the ore blend, high copper and gold recoveries were achieved in the cleaner bank. Laboratory tests suggested that increasing cleaner feed pH from 10.5 to 11.5, and 1 or collector addition to the cleaner feed, would result in improved cleaner flotation performance. These changes were trialed in the plant, with the pH adjustment being successful. High cleaner feed pH continues as a permanent modification to plant operating conditions.

The supergene mineralogy and geochemistry of numerous deposits in the Cobar region have been systematically explored in this study, with a particular focus on the oxidised zones of the Endeavour, Mineral Hill and New Cobar orebodies. A recurring pattern was identified in the oxidised mineral assemblages of the region, characterised by a multiple-stage paragenesis. Comprehensive geochemical modelling based on equilibrium processes was undertaken to elucidate the geochemical conditions under which the various assemblages formed. The exercise was extended in a series of experiments concerning the interaction of ground and vadose waters with secondary mineral species. This has led to a self-consistent geochemical exploration model for deposits in the Cobar basin. The model promises to be very useful for exploration in highly weathered terrains, particularly where the deposits lack significant surface expression. A similar approach may be relevant to exploration in other areas around Australia and world-wide. / Doctor of Philosophy (PhD)

Acid leaching of different natural chrysocolla samples under ambient conditions demonstrated that the chemical and chrystallographic inhomogenity significantly affects the rate and that it is virtually impossible to use the mineral as a model for the kinetics of hydrometallurgical processing of copper ores.Dissolution experiments, stability diagrams,and X-ray powder diffraction studies are undertaken and studied in this research and results are given.It is found that a complete solid solution series exists in Nature with most tungstenian wulfenites and molybdenum stolzites containing a range of compositions. The first occurrence of a molybdenum stolzite from Broken Hill, Australia, which also contains small amounts of chromium is noted.Raman microprobe spectroscopy has proven to be a very quick and effective non-destructive method for semi-quantitative analysis of the wulfenite-stolzite and powellite-scheelite solid-solution series and in detecting very small amounts of substituted chromate in wulfenite, stolzite and anglesite / Doctor of Philosophy (PhD)

Graduation date: 1994

The study aimed at investigating the chemical composition and microstructure of raw iron ore from the deposits in Muko area (south-western Uganda). The quality of this iron ore was evaluated to establish its suitability to serve as a raw material for iron production. Samples were taken from the six hills of Muko ore deposits and tests carried out to establish their composition and properties. X-ray diffraction and scanning electron microscopy were employed in the investigation and chemical analysis performed to determine the compounds constituting the ore. The quality of this ore was compared to generalized world market standards and ores from other nations. It was found that Muko ore is a rich hematite grade with Fe content above 65%. It has little gangue (&lt;6% SiO2 and 3-4% Al2O3) and low contents of the deleterious elements (P ~ 0.02% and S &lt; 0.006%), which correspond to acceptable levels for commercial iron ores. / <p>QC 20130531</p> / Sustainable Technology Development in the Lake Victoria Region

The blast furnace is still the dominant form of iron production, but over the years, direct reduction methods have increased due to a number of reasons. Overall, iron production methods have optimal requirements with respect to the feed materials especially iron ore. In this study, tests were carried out on Muko iron ore from Uganda to analyse its suitability to meet the feed requirements of today's dominant iron production methods. More specifically, the Tumbler, Abrasion, and Shatter Indices of the ore were determined. In addition, porosity, thermoanalysis, and reducibility tests were performed. Overall, the Muko ore was found to have good mechanical properties exemplified with tumble and shatter index data &gt;89.0 wt% and &lt;2.5 wt%, respectively. Furthermore, its reducibility at 0.87%/min is within the acceptable range as a natural material feed for blast furnace and direct reduction furnaces. Also, the energy requirement for heating the ore to 1100°C was found to be higher in the samples containing a wider size range of irregular grains and the largest contaminations. In summary, it is concluded that the Muko iron ore has good physical and metallurgical properties to serve as a natural material for the blast furnace and direct reduction furnaces. / <p>QC 20130531</p> / Sustainable Technology Development in the Lake Victoria Region

Leaching is the most widely used process for extraction of nickel metal from lateritic ores. In this study, nickel extraction from Manisa-G&ouml / rdes region laterites by hydrochloric acid leaching is aimed. The mineralogical analysis of sample showed that hematite, goethite, dolomite, quartz and smectite are the main minerals in the ore. Attrition scrubbing, cycloning and magnetic separation with permroll were used as preconcentration processes but results were unsatisfactory. HCl leaching experiments were conducted both at room temperature and at elevated temperatures. The effects of various parameters such as leaching duration, particle size, concentration of HCl, pulp density, Cl- concentration and temperature on nickel recovery were examined. The results showed that under the optimised leaching conditions (particle size: 100 % -1 mm, HCl concentration: 3 N, leaching duration: 3 hours, leaching temperature: 100 oC, pulp density: 1/30 solid to liquid ratio by volume) it was possible to extract 87.26 % of nickel in the ore.

Thesis (M.S.)--University of Missouri, School of Mines and Metallurgy, 1930. / The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed January 15, 2010) Includes bibliographical references (p. 63) and index (p. 64-65).

The Indian Creek subdistrict is the northernmost mineralized area in the Southeast Missouri district and is unique because ore-grade concentrations of sulfides occur within the Lamotte Sandstone. The Lamotte Sandstone-hosted Goose Creek mine is located on the northern end and the Bonneterre Dolomite-hosted Indian Creek mine on the northwestern side of a N30°E-trending, Precambrian rhyolite ridge. A saddle on the northern end of the ridge separates the Indian Creek subdistrict from another probable high along the same trend to the north. Lamotte deposition was influenced by pre-Lamotte basement topography, and local thickness ranges from 0 where it pinches out against the ridge to over 100 ft toward the basin. It is comprised of a thin, discontinuous basal cobble conglomerate overlain by a medium-grained, moderately to poorly sorted, well-rounded quanzarenite. Fourteen authigenic minerals, plus hydrocarbons cement the Lamotte Sandstone at Goose Creek in the following paragenetic sequence: dolomite - framboidal pyrite - marcasite - cuboctahedral pyrite - bravoite - bladed marcasite - pyrite - quartz dissolution - brecciation - siegenite - marcasite - dolomite - brecciation - chalcopyrite - quartz dissolution - sphalerite - galena (cuboctahedral) - quartz - galena (cubic) - dolomite - gypsum - hydrocarbon - kaolinite - illite - calcite - hydrocarbon. Primary and secondary porosity in the Lamotte vary between 1 and 20 volume percent and authigenic cements account for up to 35 volume percent of the sandstone. Quartz overgrowths are the most common cement in the Lamotte Sandstone at Goose Creek, comprising from 1 to 11 volume percent of the rock. Galena is the most abundant sulfide and commonly occurs in 1 to 3 mm blebs, averaging 3-4 volume percent. Chalcopyrite averages 0.5 volume percent, but high grade concentrations reach 8-10 volume percent locally. Sulfides in the Lamotte Sandstone in the Indian Creek subdistrict commonly occur within 40 ft of the Bonneterre-Lamotte contact, with the highest concentrations within 20 ft or less of the contact. Structure maps of the lead- and copper- bearing-zones mimic the basement topography, suggesting that the Precambrian basement was the major controlling factor on ore deposition in the Indian Creek subdistrict. Vertical tubes of sulfides, which cross-cut bedding near the Lamotte pinchout in the Goose Creek mine, suggest that the ore-bearing fluids moved through the sandstone aquifer until the pinchout forced them into the overlying Bonneterre. There the fluids were channeled through the grainstone-algal reef complex along the N30°E-trending Precambrian ridge. Limited fluid inclusion data for Bonneterre-hosted sphalerite indicate that the mineralizing fluid was a Na-Ca-Cl brine with temperatures between 105 and 120° C. / text