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TABAKOTO / SEGALA ? Annual gold production approximately 100,000 oz ? Debt free ? Unhedged ? Combined surface reserves 949,000 oz ? Combined 9 year life Tabakoto open pit reserve 568,000 oz (3.4m tonnes @ 5.26 g/t Au) Segala open pit reserve 381,000 oz (3.98m tonnes @ 2.98 g/t Au)

May 1, 2006

"The greatest mining center in the state of Utah is the incorporated town of Bingham about twenty-five miles southwest of Salt Lake City. The principal industry of this vicinity, prior to the early fall of 1 863, was lumbering and the first saw-mill in the state was built near the mouth of Bingham Canyon. Early in the fall of that year, George B. Ogilvie discovered gold and shortly afterward the first mining district in the state was organized. Some writers place the discovery of gold in the canyon in the late fifties. If this be so, however, the matter was kept extremely quiet because no mining was engaged in until after Ogilvie's discovery.Bingham was a placer mining camp, producing about one million dollars' worth of dust and nuggets from placers up and down the canyon and in Bear Gulch until early in the seventies, or about ten years after the discovery of gold, when a large body of argentiferous lead ore was discovered and soon after heavy shipments were made from a half dozen or more properties.In 1 8 74, A. H. and George L. Bemis erected the first concentrating plant in the state for the treatment of sulphide lead ores.The history of the camp as a producer of copper begins in the summer of 1 88 7, when Enos A. Wall noticed, in observing prospecting drifts and inclines driven some years before, the discoloration caused by the coppery solution. As a large part of the adjacent ground had been abandoned, he located two claims, which he called the ""Dick Mackintosh"" and the ""Charles Reid,"" after two of his friends.Late in 1896, the Highland Boy Mine produced sulphide ore rich in copper, causing a revival of interest in the copper potentialities of the camp, and during the next seven years a number of new claims were located ."

Jan 1, 1925

By A. D. Hammond

Vanadium is a transition metal, ductile and silver-gray. It is harder than most metals and steels and it has a good resistance to corrosion. It is stable against alkalis and sulfuric and hydrochloric acids. Vanadium is oxidized in air at about 660° C (1,220° F), although an oxide layer forms even at room temperature. The chemistry of vanadium is noteworthy for the accessibility of the four adjacent oxidation states, 2-5. In aqueous solution, the colors are lilac V2+, green V3+, blue VO2+ and, at high pH, yellow VO42-. Considered to be as abundant as zinc, metallic vanadium is not found in nature, but it is known to exist in about 65 different minerals. Economically significant examples include patronite (VS4), vanadinite (Pb5(VO4)3Cl), associated to the uranium mineral carnotite (K2(UO2)2(VO4)2?3H2O) and in a vanadium mica called roscoelite K(V3+,Al,Mg)[(Si,Al)4O10] (OH)2. Other important vanadium ore oxides are montroseite (V,Fe)O(OH) and corvusite (Na,Ca,K)V8O2.4H2O. Much of the world?s vanadium mine production comes from magnetite-hosted deposits and, to a lesser extent, sedimentary-hosted sandstone.

Dec 1, 2013

By I. K. Craig, F. R. Camisani-Calzolari

Defects which occur at the surface of a continuously cast slab impede the throughput of final product, because an extra stage in the process is required to grind the defects away before further processing can take place. Defect prediction and the minimization of the occurrence of defects is required. The use of two models to define the defect propagation is explained. Both models are derived using system identification techniques such as auto-regression with exogenous input(ARX). One model is used to determine the effect of manipulated variables such as casting speed and measured disturbances such as mould level on temperatures within the mould. The other isused to determine or indicate the effect of the mould temperatures on the occurrence of defects such as transversal cracks. The latter model can be used to predict when the defects will occur and the former can be used to control the occurrence of the defects. Keywords: continuous casting, surface defect, control system, predictor, system identification, ARX

Jan 1, 2003

By E. P. Carman

This report is the 19th in a series summarizing Bureau of Mines research and technologic work on coal and related investigations. The first 17 reports covered fiscal years; however, the 18th report3/ covered the 18 months from July 1, 1952, to December 31, 1953, to permit the publication of this and subsequent reports on a calendar-year basis. Most of the material in this report relates to publications by Bureau authors issued during the reporting period. Some work is referred to on which the results have not yet been published or may not be published for security or other reasons. In a few instances publications are mentioned that were issued before the reporting period but were not included in previous reports. Further details on the published work described herein may be found in the publications cited in the footnotes. Research and technologic work on coal by the Bureau is directed toward developing and encouraging increased conservation of coal resources through safer and more efficient mining, preparation, and utilization. Significant advances were made during the year in these fields, particularly in coal-mine safety and in preparation and utilization of the various ranks of coals.

Jan 1, 1956

By Wilson Lundy

THE history of the production of sulfur from salt domes in Louisiana and Texas originated with the operations of the Union Sulphur Co. at Sulphur, La., followed by the Freeport Sulphur Co. at Bryanmound, Tex. Including the present development of Grande Ecaille by the Free-port Sulphur Co., which constitutes the tenth dome to be equipped for the production of sulfur in the Gulf Coast, less than 10 per cent of all the known domes have proved to contain sulfur in commercial quantities. The Grande Ecaille salt dome is in the tidal marsh of the Mississippi River delta in Plaquemines Parish, Louisiana. It is 10 miles southwest of the right descending bank of the river approximately 45 miles below the city of New Orleans and is within 4 miles of the shore line of the Gulf of Mexico.

Jan 1, 1934

By P. Desclaux, A. Gosselin

"In 1999, PFC measurements were carried out at Alcan smelters as part of a large measurement campaign led by the Canadian Aluminium Association. Side worked prebake (SWPB) and horizontal stud Söderberg (HSS) plants in Arvida were the selected sites. CF4 and C2F6 emissions were measured continuously in the exhaust duct and at the roof vents for a week. In parallel, voltages from four designated cells were recorded at a high scan rate. Results were analyzed and correlations between voltage, anode effect duration and PFC emissions were tested. Some fundamental anode effect mechanisms were proposed and validated with the observations. IntroductionFollowing the international agreement reached within the scope of the Kyoto protocol, voluntary partnerships have been established in many countries especially for the aluminum industry. It is well known that the PFCs that are periodically emitted during aluminum production are the major source of fluorocarbon emissions. The latter are part of the greenhouse gases. In the fall of 1999, Alcan announced that it will adopt, promote and regularly renew a long-term greenhouse gas management commitment at all of its facilities within the framework of the so-called TARGET program that was implemented during 2001. The program is intended to produce on-going reductions, which will be reported publicly on an annual basis.Improvements in the understanding of the mechanisms leading to PFC emissions will contribute to targeting the most appropriate reduction actions. PFC measurement campaigns have been driven toward this end. The first measurement campaign was conducted in 1993 in order to get a picture of the emissions and a base line. The last measurement campaign was conducted in 1999 and its main objective was to compare current emissions with those measured in 1993 and to confirm the accuracy of the predictive equations for the calculation of PFC emissions. This campaign has been conducted by the Canadian Aluminium Association and measurements were made in plants using different technologies. Results of this campaign have already been reported by Bouchard et al. (2001)."

Jan 1, 2002

By Daniel E. Sullivan

The recession of 1974 continued into 1975. Real gross national product (GNP), measured in 1972 dollars, declined significantly in the first quarter of 1975 but rose slightly in the second and increased sharply in the third quarter. Unemployment peaked during the second quarter and then declined slowly for the balance of the year. The inflation rate declined owing to reduced demand and smaller-than-1974 increases in energy and food prices early in the year. Recovery was clearly evident by yearend, though un-employment and inflation remained at high levels. Total output as measured by the GNP in current dollars rose 6.5% in 1975. Real GNP declined 2.0%, and inflation, as measured by the implicit price deflator, increased 8.7%. Real gross private domestic investment for residential structures declined 18.1% in 1975, which was a smaller rate of decrease than the 27% decline in 1974. Real State and local Government purchases increased 2.4%, and real personal consumption expenditures for services rose 1. 7 %. The Federal Reserve Board (FRB) index of industrial production declined 9.7%.

Jan 1, 1977

By G T. Hefter, P Singh

The effect of using SO2 as an anodic depolariser in the electrowinning of copper from aqueous acid sulphate solutions has been studied using cells without/with a ceramic diaphragm. In all cases SO2-saturation of the electrolyte/anolyte decreased the anode potential by 68 to 75 per cent largely due to a change in the anode reaction from the oxidation of water to the oxidation of SO2 . However, poor quality deposits and low current efficiencies are encountered if SO2 is allowed free-access to the copper being deposited at the cathode. This situation is easily avoided by using a diaphragm to restrict SO2 to the anode compartment and for these conditions the resultant copper deposits are of a similar (high) quality to those obtained in the absence of SO2.

Jan 1, 1999

By H. R. Taylor

The history and development of this property is more or less familiar to nearly everyone connected with the mining industry, so that only a brief outline of the more important facts will be given in this article. In 1916, a small pilot mill was constructed by the British Columbia Copper Company at Copper Mountain, and during 1916 and 1917 test work was conducted to determine the possibility of concentrating the ore and also to work out a suitable flow-sheet. In the spring of 1917, the location of a mill site at Allen by, which is about 8,% miles from Copper Mountain, and near the Similkameen river, was decided on, and the designing of a 2,000-ton plant was then worked out by Bradley, Bruff and Labarthe. Early in 1918, the actual construction of the concentrator began, and, after considerable labour difficulties, it was completed in 1920. During this period of construction, the West Kootenay Power Company ran a 60,000-volt power line over from Greenwood, a distance of 102 miles, and also built a sub-station at Allenby to take care of the mine and mill. The concentrator was started up on October 20th, 1920, and ran until December 11th, 1920, a total of 18,354 tons of ore being milled. The results of this short period of operation were encouraging, but, due to tlie prevailing low price of copper and high wages, it was necessary to shut down until a more favourable time. During the latter half of 1923, some work was done on remodelling the mill. This work continued until January 8th, 1924, when it was suspended.

Jan 1, 1929

By T. C. Pool

Physical and chemical conditions permitting, in-situ leaching (ISL) of uranium offers a variety of advantages over conventional production methods including less surface disturbance and less solid waste. Commercial production of uranium by in-situ leaching techniques was initiated in 1963 in the Shirley Basin of Wyoming by Utah Construction. On a world-wide basis, ISL uranium production amounted to about 13.2 million pounds U3O8 in1999, approximately 16% of world output. Both acid and alkaline systems are used, the selection of which is primarily dependent upon groundwater quality and related reclamation requirements. ISL offers low capital costs per unit of annual capacity and is particularly flexible in adapting to changing market conditions.

Jan 1, 2000

By M Bird, B Oats, M Sganzerla

Mining operations are continually aiming to reduce operating costs to improve plant profitability. One way in which the Cannington operation sought to achieve this was by increasing the wear life and reducing the energy consumption of their flotation mechanisms. This was made possible using Outotec’s FloatForce mechanism. The FloatForce mechanism has been developed by Outotec over a six year period involving both CFD modelling and rigorous site testing. FloatForce delivers improved air dispersion and cell agitation efficiency; as such it can be operated at lower rotor tip speeds when compared to Outotec’s previous mechanism.Cannington trialled three FloatForce mechanisms in a train of ten OK38 zinc roughers. The mechanisms’ rotational speed was reduced by 10% compared to the previously installed MultiMix mechanisms. The purpose of the trial was to quantify the energy saving and assess whether there was any reduction in plant metallurgical performance.The trial was successful with FloatForce delivering a 17% reduction in power, an improvement in wear and improved recovery. Analysis of pre and post-installation metallurgical accounting data showed the following:The FloatForce installation resulted in a recovery increase of zinc to zinc final concentrate of 0.4 – 4.0%*The FloatForce installation resulted in a recovery increase of lead to zinc final concentrate of 0.0 – 0.3%*There was no statistically significant change in silver recovery to zinc final concentrate that can be attributed to FloatForce**95% confidence interval (CI) using multiple linear regression models.The Cannington operation is now in the process of further optimizing its power consumption and wear savings by changing the remaining OK38 zinc and lead rougher float cells to FloatForce mechanisms.CITATION:Bird, M, Oats, B and Sganzerla, M, 2015. Improvements in flotation cell maintenance, power consumption and operation at South32 Cannington, in Proceedings MetPlant 2015, pp 230–245 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

By D. A. Cowen

Toll and custom treatment of base metal concentrates have been performed for decades as mines and concentrators are developed distant from capital and, energy-intensive smelting and refining facilities. Commercial treatment terms have been developed and refined for over a century, and are negotiated taking into account a complex array of quality and economic factors. Treatment of third-party concentrates in the South African platinum industry is a comparatively recent development, brought about by the opening up of mineral rights and operations being developed that are smaller than the critical size required to sustain capitalization of smelting or refining plant. Published commercial terms have not been demonstrated to reflect the complexities and subtleties of base metal concentrate markets. This paper outlines some key elements and parameter ranges of base metal concentrate treatment contracts, and applies similar principles to typical Merensky and UG2 platinum group element (PGE) concentrates to determine potential value distribution between the mining and treatment parties in tolling arrangements.

Jan 1, 2012

By A. Davis, C. Webb, J. Sorensen

The abandoned Belle Eldridge Mine near Deadwood, South Dakota, is on land controlled by the U.S. Bureau of Land Management (BLM). The mine produced lead and zinc during the first half of the 1900s. Because of acidic drainage and elevated levels of metals in tailings and waste rock, the site was evaluated in 1998 and 1999. After evaluation, the mine was remediated during 1999-2001 by the BLM. Since remediation, values of pH in water samples have been nearly neutral and specific conductance values have been much lower than before remediation. The Grizzly Gulch forest fire of July, 2002, consumed much of the Belle Eldridge site and resulted in greater than normal erosion and sediment flushing during the months following the wildfire. Had the site not been remediated and the tailings emplaced within a capped repository, generation of acidity and off-site migration of heavy metals within sediments could have been severe at downstream locations.

Jan 1, 2007

By E. C. Lane

The motor gasoline that is being marketed in the United States this winter is in general, more volatile than that sold a year ago. This increase in volatility is shown by a lowering of the distillation temperatures, ranging from 2°F. at the average initial boiling point to 5°F. at the average end point. During the past eight and. one half years the Bureau of Mines has made semi-annual surveys of the gasoline marketed in the United States, the survey Just completed being the seventeenth in the series. The cities in which samples have been collected, have been chosen as representative of the more important marketing territories, as it is obviously impracticable to obtain a sample of every gasoline sold in the entire country. Samples were collected in Boston for the first time since 1919. It was believed advisable to include samples from that district in order to give a better balance to the survey for the country as a whole.

Jan 1, 1928

By T. E. Burns

The process engineer is frequently requested to select equipment to separate brine from solids, In many cases, this is a more difficult task than the selection of most other pieces of process equipment because quite often the operation of the various types of debrining equipment cannot be predicted by calculations, One must rely to a great extent upon experience or empirical test work to predict performance - that is to say one must use a practical rather than a theoretical approach. This is not to say that the solutions to liquid-solids separating problems are wholly an art but rather it is to emphasize that the approach demands a fair knowledge of commercially available liquid-solids separating equipment, some background on the advantages and limitations of each type and in many cases might necessitate a fair amount of test work, or at least, a study of performance of equipment on similar applications.

Jan 1, 1966

By W. X. Wang

In the mining and quarry industries, rock fragments are often transported by conveyor belt. To estimate the qualities of the rock fragments (i.e., size distribution and shape), an operator must take samples from the conveyor and manually perform a sieve analysis, which is time-consuming and tedious. Alternatively, an image-analysis system can be used to monitor the fragment quality on a fast moving conveyor belt. However, images of fragments on a fast moving belt vary to such a degree that the quality of any two successive images are not the same, and some of the images are of such poor quality that they are unrecognizable by human eyes. If poor-quality images are directly analyzed by a segmentation algorithm, the analysis will not be satisfactory. To resolve this problem, it is necessary to use an image-classification pro-gram for the automatic selection of fragment images with good quality. Because of this need, an image-classification program was developed and tested both in the laboratory and in the field. Testing of the system on different types of fragments showed that the system works reasonably well.

Jan 1, 1996

The main objectives of the Mine Mechanisation and Automation program (MMAP) are to enhance health and safety in underground mining operations, facilitate mechanization and automation in narrow-vein and deep mines, provide sound science to regulatory agencies and improve mine profitability. The program, which has a unique underground and surface industrial scale facility, is involved in many multi-partner projects, like hydrogen fuelcell applications, electrification and hydraulification of underground mines, reduction of noise and vibration, miner location device, explosive-free blasting and hoisting. The paper presents an overview of the Mine Mechanisation and Automation Program of Natural Resources Canada and some of the main projects.

Jan 1, 2002

By A Nugraha, H Thanasekaran, K Tatetdagat

The Kanowna Belle gold mine is located in the Eastern Goldfields of Western Australia, approximately 18 km north-east of Kalgoorlie. The processing plant is designed to process 2 Mt/y and has the capability to treat both refractory and free milling ore from the Kanowna Belle and Kundana mining operations.The Kanowna Belle ore is refractory with the gold mineralisation occurring mostly as fine-grained inclusions in pyrite or as very fine-grained gold located in pyritic arsenic rich growth zones. The Kanowna Belle refractory process includes flotation, roasting of the flotation concentrate, and calcine leaching to extract the gold from the ore.Mineralogical analysis of feed and tailings streams from the flotation circuit have shown that the gold bearing minerals are well liberated and confirmed they are mainly associated with pyrite. Nearly 40% of the flotation circuit losses are in the -38 µm size fraction. To improve the flotation circuit recovery, the fine particle gold recovery was targeted. A Cavitation Tube column was selected for the site-based pilot test work program. This paper presents data generated from the on-site test work, and the benefits of the Cavitation Tube column to improve fine particle flotation.CITATION:Nugraha, A, Tatetdagat, K and Thanasekaran, H, 2018. Flotation circuit efficiency improvement at Northern Star Resources Limited’s Kanowna Belle gold mine, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 403–412 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By A. W. Faheneald, Lewis S. Prater

By taking advantage of the fundamental difference between screening and classification—namely, that specific gravity has no effect on screening but is one of the important factors in classification—a combination of the two may be used as a process of mineral concentration. Although this fact is not new, so far as is known it has had little or no commercial application. The scheme is not presented now as a process for producing finished products but rather as a preliminary operation rejecting part of the barren material from an ore before it is subjected to more costly treatment. That is largely the function of the new heavy-media concentration processes that have been widely accepted. Original installation costs for the present sink-float processes are relatively high, however, which confines their use to operations where large tonnages are handled. Sink-float has been successful on only the relatively coarse (approximately plus 10-mesh) portion of an ore, and it is in this same range that classification screening can function most satisfactorily. Theoretically, there is no upper limit to the size of particles that can be handled in a sink-float operation, but the degree of liberation in the very large pieces usually limits this. With classification screening, particles from % to % in. would be the largest that could be handled, but the lower range could be extended somewhat below 10 mesh. In order to take full advantage of the difference in specific gravities of the minerals being separated, sorting in the classifier should be under as extreme hindered-settling conditions as possible. Laboratory tests have been made on a galena ore and on an artificial mixture of quartz and magnesite to determine the separations that may be expected. Although more than one scheme may be followed, in these tests the separations were made by cutting the underflow from the classifier as a concentrate and then screening the overflow. The screen oversize was rejected as a tailing. Classification was done in a hindered-settling teeter column and screening was done by hand, using the standard 4 2 series. The accompanying flowsheet gives the testing procedure followed.

Jan 1, 1947