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By Mike Costello

The gold mines operating within the Newcrest Group, Boddington (20% owned), New Celebration, Ora Banda and Telfer, have accumulated many years of operating experience. Cell designs and operating methods include both steel wool and woven stainless steel and plating practices cover electrowin, electrorefine, normal' recirculation and pass out modes. Besides gold the solutions contain reasonable quantities of silver, copper and nickel.

Jan 1, 1995

By A. M. Johnson, D. H. Carlson, D. L. Johnson, S. T. Bagley

A biologically assisted ferric iron leaching system was evaluated for in situ recovery of three copper sulfide oresfrorm northern Michigan. Laboratory scale bacterially assisted ferric sulfate leaching tests were run on the three ores. A T. ferrooxidans strain was found that could be adapted to copper in solutions at concentrations as high as 20 g/L. Column leaching of 4.5 to 2 mm (-4 +I0 mesh) material yielded extractions of 80-90% copper from one ore and 70 and 60% from the other ores. The highest copper extractions were from the Mount Bohemia ore deposits located in the Keweenaw Peninsula, which have fracture controlled chalcocite mineralization. The Bohemia ores are apparently well-suited for in situ solution mining.

Jan 1, 1987

By Arthur E. Goddard

Radio propagation measurements were conducted in a coal mine at UHF (200 to 1000 MHz) and VLF (1 to 50 kHz) to characterize the transmission loss of intra-mine paths. The basic experimental parameters included frequency, polarization, path orientation and distance. Further tests evaluated the performance of roof-bolt vs. loop antennas at VLF and parasitic reflectors at UHF. Measurement results are summarized in a series of transmission loss curves. Examples are presented to show the use of these curves in predicting the performance of radio communication systems in mines.

Jan 1, 1973

By R M. Hough, G Duclaux, M A. Pearce, M F. Gazley

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Microcharacterisation, such as that described in this paper, provides understanding of a mineral system at multiple scales, and understanding microscale variations is the key to understanding the large-scale variations in a mineral system. More than 50 high-grade lode samples from across Plutonic Gold Mine (Plutonic), Marymia Inlier, Western Australia were analysed by a variety of techniques, including micro X-ray fluorescence (µXRF) mapping, micro X-ray computed tomography (µCT), scanning electron microscopy (SEM), field emission gun SEM, electron back-scatter detector (EBSD), proton-induced X-ray emission microprobe and synchrotron XRF mapping. These data demonstrate that competency contrasts are the key to governing the location of Au mineralisation at Plutonic. Micro CT imaging of high-grade samples shows the Au filling in voids and pore-space in the rock, after having travelled along more permeable layers and already existing or reaction-induced pores formed during hydrothermal circulation. Using 3D visualisation, the Au is seen to form a connected network that appears undisturbed at the scale of the samples, and a high-grade Au deposition event was one of the last events to affect the rock. This interpretation is supported by SEM analyses on high-grade samples that reveal calc-silicate (epidote-clinozoisite) alteration that is not present in lower Au grade samples, which are typically dominated by potassic alteration, and that sulfides are typically less abundant close to the Au. The replacement of biotite by chlorite is an alteration associated with the high-grade Au-mineralising fluid. Gold is coarsest where Au particles are located on the margins of minerals, typically sulfide and quartz grains, suggesting the importance of rheological contrast at the microscale. Furthermore, EBSD data reveals that Au is undeformed and overprints peak metamorphic and retrograde minerals. Data confirm recent deposit-scale observations, suggesting that deposition of high-grade, visible Au was related to a hydrothermal fluid circulation event late in the geological history of Plutonic.CITATION:Gazley, M F, Duclaux, G, Fisher, L A, Hough, R M and Pearce, M A, 2015. High-resolution characterisation of gold mineralisation at Plutonic Gold Mine, Western Australia – evidence for the late-stage deposition of high-grade gold , in Proceedings PACRIM 2015 Congress, pp 51–58 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By F. W. Glaser

Iron-silicon alloys have had a great influence, in many ways, in modern industry. Silicon steels have been used almost exclusively for the construction of electrical machinery, but have also become an important material for structures which benefit by the high tensile and yield strengths of this material. In elaborating on the early history of work done on iron-silicon alloys, Greiner, Marsh and Stoughton1 went back as far as 1808, and pointed to Berzelius as the first producer of ferrosilicon. During the last twenty years some very important contributions in the form of studies of the iron-silicon system, as well as of the physical properties of these alloys, have been published. In consideration of the brit-tleness and poor machinability of alloys containing more than 5-6 pct Si, commercial interests have stimulated the research done on iron-silicon alloys, but mainly in the range of 0 to 6 pct Si. Yensen2 has shown the influence of im- purities, such as carbon, sulphur and phosphorus on the magnetic properties of 2, 4, and 6 pct Si alloys. Corson3 extended his investigation of physical properties to approximately 32 pct Si, and attributed the brittleness of the high-silicon material to the particular constitutional features of the alloys. Though mentioned earlier in the literature, the effect of nitrogen on crystal growth and magnetic permeability of iron-silicon alloys has been demonstrated recently by Morrill4 and Rostoker,5 respectively. In all the above quoted investigations, except that of Rostoker,5 sand or chill casting processes were employed for the preparation of samples. A major advantage of the powder metallurgy process is that it does away with time-consuming machining in many applications. The powder metal industry is always interested in pro- ducing a finished product employing a material which has presented considerably greater difficulties in manufacture by other methods. Steinit26 described preparation and testing of various Fe-Si alloys which were produced by the powder metallurgy process for the manufacture of armatures for small electric motors or generators. While Steinitz investigated alloys up to 6 pct Si, Rostoker5 went as high as 9 pct Si. The author7 previously discussed the diffusion of iron-silicon compacts containing 6 and 10 pct silicon. It is the object of this paper to study the progress of diffusion occurring in iron-silicon alloys by electrical resistivity measurements. All samples were prepared by pressing and sintering of compacts. Iron, silicon, and Fe-Si powders of various mesh size and compositions were employed to obtain test samples. It was assumed that complete diffusion had been obtained when the electrical resistivity reached a constant value characteristic for that particular alloy. To this end, electrical resistance measurements were used to follow the progress of alloying under various conditions.

Jan 1, 1950

By B. Denby

Recent advances in virtual reality (VR) have resulted in major opportunities for improving the safety training of mine workers, supervisors and managers. VR has the potential to expose mine personnel to hazardous situations in a safe, highly visual and interactive manner. Customized simulations of mine layouts, dynamic operations and mine environment can be set up, and mine personnel can be allowed to move around the virtual mine, making decisions at key points. The consequences of both correct and incorrect decisions can be immediately fed back to the trainee.

Jan 1, 2000

By M. M. Makhofane

Anhydrous zirconium tetrafluoride can be used as a precursor for the manufacturing of nuclear-grade zirconium metal. This can be done by fluorinating plasma-dissociated zircon with ammonium bifluoride in a batch reactor. This paper describes the batch process. It was proved that anhydrous zirconium tetrafluoride can be manufactured by this route as confirmed by X-ray diffraction. The process shows potential for scaling up to the kilogram scale and possibly the tonnage scale.

Jan 1, 2012

The carbonatite-hosted apatite deposit at the Cajati open pit mine in the Jacupiranga igneous-carbonatite complex is located in south-eastern Brazil. The major styles of apatite mineralisation include veins or veinlets, small pods or patches, disseminated apatite and locally massive aggregates. The metallurgical concentration of the apatite is accomplished by grinding the carbonatite, removal of magnetite with a magnetic drum, size classification with cyclones and flotation to suppress carbonates and collect apatite. To examine the character of the apatite grains and to apply those observations to apatite beneficiation, specimens of carbonatite were collected from recent exposures in the mine and from selected drill holes. This study utilised a variety of microscopy methods, including transmitted and reflected light, cathodoluminescence (CL) and scanning electron microscopy with wavelength-dispersive spectrometers for mineral compositions. It was found that LREE, Na and Sr are the main elements replacing Ca in the apatite, with relatively low oxide contents (<0.5 per cent, but up to about one per cent for Sr). LREE and Sr contents consistently increase in the latest intrusions (C4, C5 and SP24). Chemical and morphological modifications of apatite were recognised to be related to detrimental effects on flotation recovery. Three examples illustrate this relationship: 1.  Apatite with reddish CL is fractured. Locally that apatite exhibits no CL due to CL quenching caused by iron entering the apatite structure.2.  Apatite from the xenolith-rich area exhibits abundant fine, platy silicates that appear to interfere with flotation and lower apatite recovery.3.  So called æhardÆ apatite, which is more difficult to grind, occurs in an area in the mine that was affected by hydrothermal activity. That activity is evidenced by the development of a bright, white CL rim in the apatite, and by the presence of late veins of carbonates and sulfides that fill fractures and appear to contribute to higher cohesiveness of those apatite grains.

Jan 1, 2008

By Hall T. P, Taylor R. N

Fluid flow in a 1:14 scale water model of the shaft and settler of the Kalgoorlie Nickel flash smelter has been investigated by flow visualisation and numerical modelling. Detailed flow fields through the reaction shaft, settling chamber and uptake are presented for flow rates up to 800 Vm and a number of burner configurations. The predicted flow fields were compared with experimental data obtained from streak photographs and video recordings. The effects of cessation of flow through individual burners and changes in shaft dimensions were also Investigated.

Jan 1, 1992

By G. Chi, W. J. Davis, S. Watters, D. Hoy, S. Castonguay

"The Poplar Mountain gold occurrence in western New Brunswick is hosted in the Poplar Mountain volcanic complex (PMVC), which is located along the southern segment of the regional Woodstock fault zone. The PMVC consists of three principal units including, in ascending order, a porphyritic felsic volcanic unit, a volcaniclastic unit, and a mafic volcanic unit. U-Pb dating of zircon indicates that the age of the volcanic rocks is younger than 459 ± 3 Ma, and 40Ar/39Ar dating of mineralization-associated sericite indicates that the age of mineralization is 411 ± 3.7 Ma. Gold-mineralized zones occur in all the lithologic units but mainly in the porphyritic felsic volcanic unit. Gold zones are not controlled by individual faults but are characterized by high-density brittle fracturing, thin carbonate-quartz veining, and intensive ankerite-sericite alteration, superimposed on an earlier chlorite-calcite- quartz alteration. Gold is associated with arsenopyrite, which mostly occurs as disseminations in the host rocks, and to a lesser extent with quartz-carbonate-sericite veins and quartz-cemented breccias.Geochemical data indicate that mineralization-associated alteration is characterized by enrichment of K, Rb, Cs, Ca, Sr, Ba, As, Sb, W, C, and S. Fluid inclusion data indicate that the mineralizing fluids are composed of H2O, salts, and CO2 with variable amounts of N2 and CH4; salinities range from 2.3 to 10.6 eq. wt.% NaCl, but mainly from 2.3 to 5.6 eq. wt.% NaCl, and homogenization temperatures lie mainly between 220° and 270°C. Fluid pressures at the site of mineralization are estimated to have been 770 to 1200 bars, corresponding to a depth of 2.9 to 4.6 km at lithostatic pressure. The d18OSMOW and d13CPDB values of mineralization-related ankerite range from +14.5‰ to +16.5‰, and -6.8‰ to -8.3‰, respectively. The d18O values of the ore-forming fluids are estimated to be 6.4‰ to 8.3‰ at a temperature of 250°C. These carbon and oxygen isotope data fall in the field of magmatic fluids and in part the field of metamorphic fluids.Considering the geological setting of the region, abundant granitic intrusions, the similarity between the age of mineralization (411 ± 3.7 Ma) and the nearby Pokiok batholith (402-415 Ma), and the enrichment of granophile elements in mineralization-related alteration, the ore-forming fluids were probably derived from a granitic intrusion underneath the PMVC. These fluids were focused along structures related to the Woodstock fault. The Poplar Mountain gold occurrence might be compared to some granitic intrusion-related gold systems based on the geochemical data presented herein. L’indice aurifère de Poplar Mountain dans l’ouest du Nouveau Brunswick est contenu dans le complexe volcanique de Poplar Mountain (CVPM), lequel est situé le long du segment sud de la zone de faille régionale de Woodstock. Les trois unités principales du CVPM sont, de la base au sommet, une unité volcanique felsique porphyrique, une unité volcaniclastique et une unité volcanique mafique. La datation U-Pb de zircons indique que les roches volcaniques sont plus jeunes que 459 ± 3 Ma, et la datation par la méthode 40Ar/39Ar de séricite associée à la minéralisation assigne à la minéralisation un age de 411 ± 3.7 Ma. Bien que les zones minéralisées en or soient présentes dans toutes les unités lithologiques, on les retrouve surtout dans l’unité felsique porphyrique. Les zones aurifères ne sont pas contrôlées par des failles individuelles mais sont caractérisées par une grande densité de fractures cassantes, de minces veines de quartz-carbonate, et par une altération en ankérite-séricite intense qui se superpose à une altération antérieure en chlorite-calcite-quartz. L’or est associé à l’arsénopyrite, laquelle est principalement présente à l’état de disséminations dans la roche hôte, et à un moindre degré avec des veines de quartz-carbonate-séricite et des brèches à ciment de quartz.Les données de géochimie indiquent que l’alté"

Jan 1, 2008

By M. L. Skow, Maurice Deul, M. G. Zabetakis

This Bureau of Mines report presents a brief summary of the explosion trends in United States coal mines for the past 160 years. These trends show that in spite of the overall improvements in mine safety, the number of fatalities from ignitions of methane has actually increased in recent years. Suggestions are made of procedures that can be utilized to reverse this trend.

Jan 1, 1972

By U. Dillon, G. Blackwell

"Geographic information systems (GIS) provide an efficient means for the recording, manipulation, revision, display and analysis of spatially referenced data. GIS are widely used at the exploration stage of mine development, and are increasingly used for reclamation planning. The ability of a GIS to perform spatial searches and query spatially referenced data make it a powerful tool for use at all stages of mine development. As the amount of data available for analysis increases, so does the power and flexibility of GIS as a planning tool.Starting from the exploration database, this paper describes how a GIS can be used for the development of mining plans based on topography, geology and mineralization information stored in a relational database. Planning decisions approaching the optimal can then be made for a wide range of parameters, including stockpile and waste dump locations, the location of potentially acid generating and neutralizing material for dump design, profitable and risk-controlled mine extraction sequencing, and haul road locations. This is made possible by the overlay and buffer analysis capabilities of a GIS which are explored and exploited to produce a continuous mine production planning program, as well as site remediation and reclamation using a successful case study. The Ore and ProductsThe mines in the Saskatoon area — Agrium, PCS-Cory, PCS-Allan, PCS-Patience Lake, PCS-Lanigan and IMC-Colonsay — extract the ore from the Patience Lake member. The mines in the southeast corner of Saskatchewan — IMC-K1 and K2, PCSRocanville — extract from the Esterhazy member, while IMC-Belle Plaine, near Regina, solution mines potassium chloride from both potash-bearing members.Ore from the Patience Lake member is a medium-grained mixture of sylvite and halite, with a KCl content of 36%, insolubles averaging up to 5.5%, and little or no carnallite.The ore from the Esterhazy member is a coarse-grained mixture of sylvite (KCl) and halite (NaCl) with a small amount of water insolubles, and some carnallite (a K-Mg chloride). Average run-of-mine grades are about 30% KCl."

Jan 1, 2003

The Golden Cross mine is a Joint Venture between Coeur Gold New Zealand Limited, as Manager, and Viking Mining Limited. The mine is targeting Zero Lost Time Accidents as a goal.   The Golden Cross operation produces gold and silver from both underground and open pit. The mine is based on an epithermal gold-silver deposit. Treatment of ore is on a campaign basis for each ore type (i.e. underground or open pit). Milling is conventional SAG Mill and Ball Mill grinding circuit followed by carbon in pulp recovery of gold and silver. All tailing materials are treated through the Cyanisorb process to reduce cyanide levels prior to being discharged into the tailings dam.

Jan 1, 1995

By Kent D. Mctyer

Mining commenced at Tasman Mine in late 2006. The current method of mining is bord and pillar using continuous minerbolters and shuttle cars for first workings and secondary extraction using mobile roof supports. The two stage process was chosen to accommodate irregularly shaped coal deposits, allowing adjustments to be made to extraction ratios for better management of subsidence and to maximize the efficiency of the operation. Following the completion of the first three full/partial extraction panels, the mining method was changed due to variable caving. Another partial extraction method, referred to as the Duncan Method was adopted; it involves stripping the developed square pillars on four-sides on retreat to leave a load-bearing remnant coal pillar. The system of partial extraction has been successful in meeting safety, productivity, and subsidence targets.

Jan 1, 2011

By Harold Wahlborg, George Owusu

In a study using butyl diglyme as an organic extractant, essen­tially complete extraction of gold from chloride leach solution was achieved. The extraction kinetics are so fast that the process could be completed in 30 seconds. Except for iron, co-extraction of other ionic species was insignificant. Co-extracted iron species were successfully scrubbed from the loaded organic using 10% HCl solution. High grade, >99.9%, gold was recov­ered from the loaded organic using 5% oxalic acid solution as the stripping agent at a temperature of 70°C to 80°C. Over 99% of the organic-loaded gold was stripped from the organic phase. The butyl diglyme extractant is being tested on a variety of gold-bearing feedstocks. Presented here are results obtained from two gravity concentrates.

Jan 1, 1999

The paper describes the reasons for the development and for the selection of systems which were finally adopted; further estima- tion and design engineering problems, as well as experience with large screens in operation. Advantages, disadvantages and the final li- mits of screen dimensions are indicated.

Jan 1, 1984

By K E. Barns, P J. Sharman, S A. Thomas and

This paper presents the development of a regrind facility design at BHP BillitonÆs Leinster Nickel Operations (LNO) in Western Australia. The recovery opportunity was identified from an analysis of plant operating data together with scanning electron microscope (SEM) measurements on relevant tailings streams from LNO. A laboratory procedure was developed to determine the potential recovery improvement of installing a regrind facility at LNO. The last step in formulating the process flow sheet and defining the process design criteria was to construct and operate a pilot plant, which incorporated four banks of flotation cells and an Xstrata M20 Isa Mill. Pilot plant on/off trials were used to define the expected metallurgical benefit. A prefeasibility engineering design and cost estimate was completed. Following a successful internal business evaluation, a feasibility study is currently underway.

Jan 1, 2007

By L. J. Howell, A. S. Roy, H. H. Kellogg

KNOWLEDGE of the phase diagram of salt systems is important for selection of the optimum con- ditions for electro winning of the refractory metals from fused salts. This note summarizes the studies of the NaC1-rich portion (0 to 22 mol pct HfC14) of the NaC1-HfC14 phase diagram. Melts in this composition range have vapor pressures well below one atmosphere and melting points between 548° and

Jan 1, 1959

By John Gross

THE deductions drawn in crushing and grinding operations have heretofore been based on a separation of the products into various sizes. A crushed product may be sized by sieving, by elutriation, and by aid of the microscope. To estimate the surface of each size the relation of the surface to the estimated average diameter must be assumed. Such a relation, owing to the irregularity of the particles, may involve two assumptions: First, a factor to convert average diameter to surface for one particular size; and second, a variation in the factor as the diameter of the particle changes. Obviously a surface measurement in which such assumptions and estimates are involved is questionable. In the first paper of this series1 a method has been given by which an accurate measure of surface of quartz can be obtained from its dissolution rate. By the use of this method, surface measurements have been made on a series of sieve sizes of crushed quartz, the results of which are given and discussed in this paper.

Jan 1, 1928

By R. E. Hanneman, A. N. Mariano

In conjunction with the need for accurate volumetric data in the Fe-V system for subsequent use in calculating the high-pressure diagrams, room- and high-temperature X-ray diffraction measurements have been carried out. No previous measurements have been published on lattice parameters or volume changes associated with the a transformation for Fe-V alloys. The existing literature on lattice-parameter data for the a and s phases has been reviewed by pearson1 with considerable uncertainty indicated in the data. In order to obtain a good estimate of ?Va-? for thermodynamic calculations of the a D ?(bee D fee) phase stability, high-temperature vacuum X-ray diffraction measurements were made on an Fe-V alloy of 0.92 wt pet V. The term ?Va-? is the difference of molar volumes of the limiting solubilities of the a and y phases at any given temperature; these values can be calculated readily from the appropriate lattice-parameter data. The equipment used was a commercially available MRC (Materials Research Corp.) high-temperature X-ray camera which was fitted to a Norelco diffractometer

Jan 1, 1964