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By D. Lemieux

A gold bearing pyrite concentrate was treated at the pilot scale for the extraction of gold. Mineralogical analysis of the concentrate identified gold to be mainly present in the form of a solid solution in pyrite. This gold distribution resulted in a poor extraction yield of 55% by direct cyanidation. A piloting campaign including an oxidative pre-treatment by roasting in a fluid bed was followed by treatment with halogens for gold extraction has led to a gold extraction yield of 96.5%. Sulphur removal during the oxidation was very efficient at >99.5% and gold extraction by the halogens was completed within a 1 hour contact time. The piloting was performed on a 300 kg sample and uses a diluted solution of hypohalites as the oxidizing agent for gold extraction. Sulphuric acid was injected in the reactor during the halogens treatment to lower pH to 2. The diluted solution of hypohalites (1-3%) was generated by electrolysis during the piloting campaign in a membrane-less electrolysis cell. The extracted gold was recovered over activated carbon in column and the gold depleted brine was treated for impurities removal and recycled for further gold extraction. With the recycling of water and brine, the regeneration of hypohalites and with a barren solid that is inert and stable, the Nichromet Extraction technology is a green process where the protection of the environment does not preclude profitability.

Aug 1, 2013

By C. L. Dake

Iron is much more soluble in the ferrous than in the ferric form. Where, as in the case of the ferrous silicates and. the sulphides, the iron is already in the ferrous form, it may go at once into solution and be removed, upon the breaking down of the parent rock. If in the ferric form, it must first be reduced; usually by the decay of organic matter, the demand of the decaying carbonaceous matter for oxygen being so great that the latter is abstracted from the ferric compounds and the iron is thereby reduced and rendered soluble. The iron may go into solution as the sulphate, or in the presence of excess CO2 as ferrous carbonate. It is probably soluble as salts of the organic acids.' Recent work indicates that these are important in the formation of bog ores.2 There is considerable variety of opinion concerning the behavior of these organic compounds.3 The secretions about the roots of plants and trees also cause the solution and removal of iron and a consequent bleaching of the soil,4 While the matter is not yet well understood, we can probably say definitely that the so-called organic acids are a group of colloids which possess slightly acid properties, and the salts of which are partly soluble and partly insoluble.5 Their iron salts readily change from the ferrous to the ferric form, and their solubility is greatly modified by the presence of ammonia.

Jan 1, 1916

By Lorraine Kent

Excessive floor and side deformation are major problems in deep coal mine entries in Europe, and in particular in the UK where rockbolt support is used at depths of working of around 3000 ft. This has major economic and safety implications for the industry resulting in the potential for sidewall instability, disruption to mine infrastructure, (belt conveyors, floor mounted transport systems and powered supports), and the requirement to safely manage excavation of large quantities of floor material. European research aimed at improving deformation control is described. The outcomes include innovations in support systems, materials and installation practices, as well as better methods for predicting and monitoring deformation levels. As coal mines get deeper, some entry deformation is inevitable, and methods for mechanised removal of floor lift and repair of sidewalls have been developed to allow production to continue as mining clearances are re-established.

Jan 1, 2014

By Gary E. Sherman

The Bureau of Mines estimated the remaining lode gold endowment of eight mining districts in Alaska using historic production data. A log-arithmic model of cumulative tonnage of ore processed versus cumulative grade was applied to the following districts: Chichagof, Fairbanks, Homer, Hope-Seward, Juneau, Ketchikan, Prince William Sound, and Willow Creek. To assess the remaining endowment, a computerized production data base was compiled from Bureau records. These data were aggregated in 5-yr intervals for each district. Data were sorted in order of declining grade, and log cumulative grade was plotted against log cumulative tonnage. Linear regression was performed on the data for each district. The linear equation for each curve was used to predict remaining endowment at a limiting mining grade. Based on conservative extrapolation of the grade-tonnage curves, a substantial total endowment of 8,415,100 tr oz of gold remains in the eight districts. The districts with the greatest remaining endowment are the Juneau, Chichagof, Fairbanks, and Willow Creek Districts.

Jan 1, 1987

By S Romanchuk, V N. Macvkiw, D. J. I. Evans

The paper describes the processes developed and piloted by Sherritt Gordon Mines Limited for recovering copper, in the form of specification copper powders, from Lynn Lake sulphidic copper concentrates and Fort Saskatchewan Refinery by-product copper sulphides. The process includes ammonia pressure leaching and hydrogen reduction from solution. Nickel and cobalt present in the con-centrates dissolve in the leach solution and a method was developed for separating these metals from the cop-per. Methods are described for con-trolling the physical properties of the copper powder produced in the reduction vessel. The chemistry of the process is briefly discussed and the effects of some of the more important process variables are described. SHERRITT Gordon Mines Limited have developed and proven on a pilot plant scale, a process (I) for the production of copper powder

Jan 1, 1961

By F. G. Prado

The technology for the extraction of zinc from zinc residues, such as zinc ashes, drosses and metallurgical flue dusts, by way of ammonium chloride solutions is well established, at least at the laboratory and bench scale levels. (3, 4) Zinc is soluble in ammonium chloride solutions in the form of zinc diammine chloride. Its solubility depends upon the concentrations and temperatures employed. The procedure and the equipment required are simple, and they can be applied either to small or large operations. As a by-product, zinc diammine chloride is produced with extremely low impurities in quantities which are stoichiometrically proportional to the zinc removed. The technology has been applied experimentally to galvanized steel residues. The dezincing results, including removal performance, energy and reagents required, and by-products are summarily presented in this paper.

Jan 1, 1992

To simplify programming, image analyzers commonly measure either linear intercepts or the areas of particles and grains to determine liberation based on polished section mounts. However, the concentration of minerals by flotation is based on reagents that interact with the exposed surfaces of the minerals. Thus, it is often perceived that image analyzers should measure the perimeter of the mineral of interest in the ore particles. A comparative liberation study of thirteen samples collected from a flotation plant processing a complex base metal sulfide ore showed that the liberation of the ore minerals determined by area measurements is very similar to the liberation determined by the exposed perimeters. The liberation determined by exposed perimeters is more appropriate only for those cases where the mineral texture is so complex that it is retained in the small particles generated in conventional grinding operations.

Jan 1, 2002

By R K. W Merkle, S Madoom Hussain, T Yellappa

Cr-Ni-Cu¦PGE deposits are known to occur in early Archaean mafic-ultramafic rocks. Early Archaean mafic-ultramafic (MUMF) rocks occur in the western Dharwar craton and range in size from small pods to schist belts. These MUMF pods consist mainly of meta-peridotites, tremolite-actinolite schists, serpentinites, amphibolites and metabasalts. Spinifex, nodular and ocelli textures are also present. The rocks have been subjected to greenschist and amphibolite facies metamorphism. Geochemical studies were undertaken to evaluate the possible occurrence of economically important elements in the mafic-ultramafic enclaves around the major Arsikere-Tavarkere lineament and surrounding gneissic terrain adjoining local shear zones that occur as discontinuous pods between Arsikere and Chennagiri. Talc-serpentine and tremolite- actinolite schists contain chromite which is rimmed by ferrit-chromite. A notable feature of these MUMF rocks is that they exhibit high MgO (22 - 40 per cent), total iron (8.34 - 10.01 per cent), Ni and Cr (~3000, 2800 ppm) contents, with some samples showing komatiitic affinity. The rare earth elements (REE) data show slightly fractionated patterns with enriched LREE (LREE/HREE ~5.0) and negative europium anomalies. The Pt and Pd values reach 6500 and 191 ppb. The MUMF rocks, especially those exhibiting high chromium contents and occurring near shear zones, are potential hosts for economic platinum group element (PGE) deposits.

Jan 1, 2008

By Shijie Wang

In pressure oxidation leaching of copper anode slimes, than 65% of the tellurium is m' cxtraoted during decopperizing. About l0- 15% of the selenium is also dissolved simultane¬ously by severe leach conditions. Current operation for the treatment of the leachate is to constantly recirculate the leach solution through a bed of copper turnings. The tellurium and sele¬nium are precipitated from the leach liquor as copper telluride and copper selenide and sepa¬rated from the solution by filtration. In order to improve the reaction efficiency and reduce the process cost, viz, minimize the copper addition, cut retention time, and reduce the energy consumption; a chemical reducing agent is studied and the cementation process tested in the laboratory. In this paper, the test results are presented and the process chemistry is discussed.

Jan 1, 2003

By E. H. T. Whitten

Fundamental principles of trend surface analysis are briefly reviewed. Recent analyses of several granite masses illustrate the method of estimating the quantitative regional composition and also variation trends. Mineralogi-cal, bulk chemical, and other quantitative variates can be employed. Such results should improve gravimetric surveys (etc.) relying on correction terms based upon estimated rock composition. For the first time realistic estimates of the mean composition of rock bodies can be made with the aid of trend components. Deviation maps hold promise for delimitation of disseminated mineralized areas. Deviations comprise residual "anomalies" after removal of trend components. In petrogenetic work such deviations have been shown to reflect local influences (e.g., contamination of magma by assimilation of xenoliths or country rocks of the envelope). Similarly, mineralization should be reflected as deviations standing out from background trends. Actual examples are given. Present results largely involved projection of data onto a horizontal plane, but if sufficient data are available use of three spatial coordinates increases accuracy for prediction in "unexposed" areas. Regression analysis shows that statistical correlations between variates for regionally distributed specimens are often strong (particularly with percentage data). Hence, in preliminary surveys more easily determined variates may sometimes be employed to gain first estimates of the distribution of components more economically significant. The sampling plan is of paramount importance. Unless a suitable sampling plan is devised and adhered to rigorously during collection of the samples, all subsequent analysis is liable to strong bias and to yield spurious estimates of the truth. For a wide variety of purposes it is becoming necessary to assess the quantitative composition and variability of rock masses and mineralized zones of various types. In petrology and petrography this is something of a break with tradition, because virtually all descriptions heretofore have been qualitative. Although vast amounts of qualitative data have been compiled, little is known about the quantitative behavior of rock components. However, if variability of rocks could be understood and expressed with sufficient accuracy, there would be considerable advantage to both economic and petrogenetic problems. For example, if, on the basis of a limited series of observations, the three-dimensional geometry of a disseminated orebody (or ore-bearing formation) could be predicted accurately, it would be possible to extrapolate with confidence the structure into unexposed areas. The following example based upon the geometry of an igneous cone sheet illustrates the point. The significant rock-unit gives outcrops at a number of points on the exposed surface ABCD (Fig. 1A). Study of n exposures may enable a geologist to predict that the rock-unit is circular in form and thus indicate where the unit can be expected in unexposed terrain. Such observations are made at sites with u, v coordinates, but, if subsurface information is available at sites with uvw coordinates, it will eventually become possible to predict accurately the three-dimensional form of the rock mass. Geologic rock masses or mineral deposits are not generally as regular and symmetrical in geometric form as the body illustrated in Fig. 1A. However, even where the broad limits of a major rock mass are known, a more acute problem arises in attempting to obtain detailed quantitative estimates of its internal variability; it is difficult to predict the variability of a mass from a limited number of observa-

Jan 1, 1961

By Cesar Garban

The samples of the washings are characterized of the ore for physical, chemical and metalurgical properties for representivity. the optimum values are determined for the recuperation of gold of the washings of the gold ore from the zone El Callao, Venezuela by acidic solutions of thiourea of the following parameters: Ph , contact time, composition of the liquid mixture, ratio of solid to liquid, grade of liberation, in an apparatus designed for contacting solid powder of the mineral with liquid solution of thiourea mantained in suspension by bubles of compressed air. The experimental results showed that the velocity of lixivation in primier time of (20) minutes is rapid and practically 2/3 part of the reaction is completed. For experimental design of parameters, the optimum conditions of recuperation of gold determind in this experimental investigation are:

Jan 1, 1999

By C. A. Rowland

With the rapidly rising cost for electrical energy and the long range pre¬dictions for continued rising costs and even possible energy shortages, operation of rod, ball, autogenous and partial autogenous grinding circuits to efficiently utilize the power delivered to the mills will be demanded. This calls for a method to evaluate grinding circuit performance that is accurate, reliable and readily usable as an operating tool by supervisory, technical and operating personnel. Neither the Rittinger and Kick theories of comminution,(1) which preceded the Bond Theory by more than 50 years, had a mathematical means that could be used to predict and evaluate the performance of crushers and grinding mills used to comminute ores and rocks. This severly limited the practical use of these two theories, which were contradictory to each other. They have been superseded by the Bond Third Theory of Commnution.(1)

Jan 1, 1976

By Charles G. Kemsley

IN view of the truly remarkable development of special steels for special purposes, the mining industry has for years looked forward to a time when steel makers would come forward with a product which would be an improvement over the straight carbon steel which has always held the field for drilling rock. In order to avoid making changes in conventional shop practice, the industry has perhaps been too insistent upon obtaining a water hardening steel which could be handled in the blacksmith shop by long established methods. As early as 1932 or 1933, an oil-hardening tool-steel of the one per cent carbon, plus chrome, plus molybdenum type was applied to hollow drill steel. It was known as a hard as well as a tough steel, and one that, theoretically, should give a good account of itself as a rock drill, if properly heat-treated; and so it has proved in actual trials. There were numerous deterrents which retarded adoption of this steel. For several years there has been a constant improvement in the drilling qualities of the straight carbon steel, and, considering the higher unit price ? of the alloy, there has been considerable doubt in the minds of some mining? men as to what advantage there might be in the use of alloy over straight carbon for hollow drill steel. The alloy being an oil-hardening steel, its adoption meant having two kinds of steel in the mine, for a time, and that spelled trouble, unless some positive means of identification was adopted. The hardening and forging ranges of alloy steel being narrow also made necessary much closer control over these operations if poor results were to be avoided. These thoughts undoubtedly prevented its use becoming wide-spread, for, as a matter of actual record, less than fifteen per cent of all the hollow drill steel used in Canada today is alloy.

Jan 1, 1942

Study on Mineral Processing for a Cassiterite Ore in Southwest China

Sep 13, 2010

By V. I. Zhuchkov, L. A. Smirnov, E. I. Arzamastsev, A. A. Babenko

A brief analysis is given for state-of-the-art of manganese and chromium ferroalloy production in Russia and their consumption by metallurgy plants. The main causes of low output of manganese and chromium ferroalloys, and ways to resolve the issue of ferroalloy production development are considered.

Jan 1, 2004

By E. R. Maize

This report is t e second of s series on roof movement in coal mines. The first (R. I. 3355)4/ dealt with convergence of roof and floor and movement of the surface accompanying and following extraction in a mechanized mine in which retreat of rib lines was rapid. The studies reported herein were made in a mine in which all the coal is loaded by hand, and movement of the rib lines was much slower in consequence. In choosing a site for this work, it was decided that the mine selected should have natural conditions akin to those of the first study and entirely different methods of working. To this end a cooperative agreement was made with the Crucible Fuel Co. through W. J. Whitaker, secretary, for conducting the work in the company?s Crucible mine, operating in the Pittsburgh bed in Greene County, Pa, This paper gives an account of the methods used in the investigation, excerpts from the data obtained, and such generalizations as can be made.

Jan 1, 1939

By W Akpan

The Royal Bafokeng community in South AfricaÆs North West Province represents a unique case in Sub-Saharan Africa in terms of its positioning in the natural resource economy. It receives royalties directly from mining firms for the extraction of Platinum Group Metals, which include platinum, ferrochrome, rhodium and palladium. In 2007, royalty income of about R290 million (approximately US$32.2 million) was reported. Such direct revenues have enabled the community to invest in educational, medical and other social infrastructure, thus complementing governmentÆs social provisioning efforts. Indeed, the Bafokeng community owes its present-day modernisation efforts to mineral rights, and in particular, the legal-institutional arrangement that has enabled it to play an active role in South AfricaÆs lucrative extractive economy. However, the distribution of platinum wealth in this community is not only uneven, but also appears to have had little impact on the broader socio-economic conditions in the community. Despite claims by community leaders of heavy investment in education and skills development, the community continues to be faced with very high levels of unemployment, illiteracy, sprawling informal settlements, poor access to medical facilities and malnutrition. This paper examines the sociological paradoxes and contradictions thrown up by the approach adopted to involve community members in the mobilisation of mining royalties for developmental ends. The central argument is that the current æmodelÆ contradicts the communityÆs stated goals of using platinum wealth to drive up broad-based development and modernisation. This is mainly because it leaves out the vast majority of community members, who are uneducated and unskilled. The core analysis is based on pilot data from an ongoing study in the Royal Bafokeng community.

Jan 1, 2009

By L Huang

"Successful rehabilitation of tailings landforms of tens to thousands of hectares in size at base metal mines is critical to mining companies’ ‘social licence to operate’. Rehabilitation technology used is closely related to both the economic sustainability of the mining company and the ecological sustainability of the mined environment. Conventional technology to rehabilitate mine waste landforms is costly and constrained by the availability of soil (to reconstruct root zones) and clay materials (to reconstruct compressed layer). Depending on mine waste properties and site-specific resource availability, it is not uncommon to cost A$0.1–0.5 M/ha for the establishment of conventional cover systems over mine waste domains, which often accounts for large proportion of the total closure costs. This can lead to costs approaching several hundred millions dollars for rehabilitating larger tailings and acidic waste rock using conventional cover systems.The present extended abstract proposes a suite of new technologies to tackle the problems outlined above and discusses critical factors in successful rehabilitation from substrate levels to the whole landform performance, in two key aspects:in situ engineering of tailings soil to offset/reduce materials requiredin situ chemical engineering of massive hardpan layer through alkali-activation and mineral gel cross-linking network mechanisms to encapsulate reactive tailings and achieving sustainable hydro-geochemical stability in root zones.This aims at functionally replacing the roles of the compressed clay layer and capillary breaks in conventional covers. These technologies would improve both the economic and ecological sustainability of mine waste rehabilitation, thus addressing the triple-bottom line of mining and mineral processing industries not only in Australia but other countries.CITATION:Huang, L, 2016. Emerging technology for economic and ecological sustainability in the rehabilitation of metal mine tailings, in Proceedings Life-of-Mine 2016 Conference, pp 128–131 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 28, 2016

By J. W. Thompson

SALE AND CONVEYANCE. DEED BY INDIAN ALLOTTEE OF UNSOUND MIND-BONA FIDE PURCHASER. The deed of an Indian allottee whose mind was unsound, but who was not entirely without understanding, is voidable if made before the grantor's incapacity has been judicially determined; and a purchaser of the original grantee who interposes the defense of a bona fide purchaser has the burden of showing a purchase for value and on failure to do so can not claim the benefit of a bona fide purchaser. Adams Oil & Gas Co. v. Hudson (Oklahoma), 155 Pacific, 220, February. 1916. PURCHASER OF MINING CLAIM-RIGHT TO FIXTURES. The purchaser of a mine equipped with an electric hoist, placed in the mine under a rental contract with the owner of the hoist and under an agreement to return it to the owner at the expiration of the term of hiring, can not claim and hold the hoist as against the owner where the agent of the seller explained to the purchaser that the hoist was not owned by the owner of the claim. Montana Electric Co. v. Northern Valley Mining Co. (Montana), 153 Pacific, 1017. p, 1018, October, 1915. AUTHORITY OF GRANTEE TO EXTEND LEASE. A deed conveying lands subject to an oil and gas lease under which the lessee had the right to drill or pay money in lieu of drilling at his option, and reserving to the grantor a share of the royalties under such lease, and expressly authorizing the grantee to lease the land for oil and gas purposes and to take the rentals, authorizes the grantee to extend the existing lease before the expiration thereof in consideration of the annual payment of money in lieu of drilling, as contemplated by the lease.

Jan 1, 1916

By H. Lyn Bourne

Daily everyone depends on the great variety of glass products, so much so that glass is often taken for granted. In fact most people do not realize how versatile glass has become. Consider the various uses and then try to imagine a day in which we are not influenced by glass. Common uses include container ware, table ware, window glass, lead crystal, automobile glass, and fiber glass. Several less common, but important, uses include laboratory ware, pharmaceutical, TV bulbs, light bulbs, glass ceramics, optical glass, fiber optics, and laser glass. Corning, Inc., a leader in specialty products, uses nearly 1 000 different compositions to manufacture about 60 000 different products (Edwards and Copley, 1977). Glass is such a complex product that-definitions vary and exceptions can be found for most definitions. Glass is an inorganic amorphous (non-crystalline) solid. Most glasses are produced by melting of a mixture of oxide raw materials, and then cooled to room temperature. Soda-lime-silica composition.s account for about 90% of all glasses melted (Anon, 1973). The properties of the glass product come mainly from its chemical composition. All of the different glasses require melting a combination of raw materials and forming the molten material into the desired shape. Both the melting and the forming processes use sophisticated technology and these technologies require experts to manage these production systems. The manufacturing process is continuous and takes place in tonnage quantities, so adjustments in the batch to achieve the desired finished product requires a great deal of expertise. Raw materials are fed to the batch mixing area in very large quantities (tons in most cases). As a result, impurities in the range of 0.1% result in addition of that impurity within the molten glass in kilogram amounts. More than twenty different industrial minerals are consumed in the manufacture of various kinds of glass (O'Driscoll, 1990). This chapter describes the major and minor ingredients of the various glass batches. It discusses the roles of the various oxides in the glass batch and most importantly considers the mineral raw materials which supply the glass industry. Each of the raw materials is described in detail in other chapters so the geology and mineralogy sections are kept brief here. Container glass, by far, accounts for the most production; followed by flat glass, fiber glass, and specialty glass of which table ware accounts for the greatest tonnage. [Table 1] shows the general production data for 1987 through 1990. Statistics for many of the uses do not appear because production volumes are small compared to the major uses. The glass industry is organized in four categories: containers, flat glass, fiber glass and specialty glass. The US Department of Commerce, Bureau of Census, publishes production data about the glass industry in three different categories: 1) glass containers, 2) consumer, scientific, technical and industrial glassware, and 3) flat glass. The Bureau has very complete statistics about the glass industry in these three categories but they report production data in different units according to industry standards. Therefore, [Table 1] gives the production data in dissimilar units. The production of most glass articles follows similar steps. The raw materials are mixed and the resulting batch is fed into the furnace. In soda-lime-silica glasses melting begins between 600 and 900°C. At these temperatures CO, and other gasses are released which create bubbles in the molten glass. To remove the bubbles and insure complete melting the temperature is raised to between 1 500 and 1 600°C. This is the melting-refining stage during which the refining agents in the glass batch serve to aid in the release of gas bubbles, homogenize the melt, and prevent the formation of scum on the surface of the molten liquid. At the conclusion of the melting-refining stage the glass is too fluid for working and the melt is cooled to about 1 100°C to attain the proper viscosity for working and forming to begin. After the glass article has been made, it must undergo annealing (slowly and uniformly reheated and cooled) to remove thermal stresses that were created during the forming process.

Jan 1, 1994