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By Albert Sauveur

As director of the Division of Metallurgy of the Technical Section of the Air Service, American Expeditionary Forces, from August, 1917, to January, 1919, I devoted much time to the study of the steels best suited to the construction of aircraft. It became apparent at a very early stage of my investigation that the practice of builders varied greatly in regard to the number of different steels to be used, to the kinds of steels, and to their treatment. Some manufacturers employed as many as fifteen steels while the builder of one of the newest motors, favorably passed upon in the United States, assured me that two or, at the most, three kinds of steel were all he needed to produce satisfactory results. In the matter of treatment, the manufacturers were also greatly at variance. Some treated their steel with considerable refinement while others paid but scant attention to this feature. Some manufacturers case-hardened many parts, while others used the case-hardening process sparingly, if at all. Nickel-chromium steels were used at some works for case-hardening while at other plants this treatment was applied exclusively to carbon steels. Air-hardening nickel-chromium steel was used extensively by some and not at all by others. Considerable variance existed likewise in regard to the steels used for admission and exhaust valves. The conclusion was obvious, that no two manufacturers of airplane motors held like opinions as to the steels to be used or as to the treatment they should receive. Was it to be inferred from this that the many committees and associations that had been created, in part at least, for the standardization of aircraft steels had failed to make proper recommendations or that the manufacturers had ignored their recommendations ? Confining our inquiry to the committees and associations that had dealt with this question in England, France, and the United States, it was found that in Great Britain the British Engineering Standards Committee, now the British Engineering Standards Association, had devoted much time to the problem of satisfactory standards for aircraft steels. In April, 1918, this Association presented a set of specifications described as "British Standard Specifications for Aircraft Steels for Government Purchases in the United States of America." They included twenty-one different steels and, as the title indicates, were drawn for the

Jan 1, 1920

By N. L. Hayward, V. H. Ness

In the past decade Australia has seen the development, construction and commissioning of three complex processing plants for the treatment of lateritic nickel ores. These have all been based on high pressure acid leaching (HPAL) for extraction of nickel and cobalt into solution, followed by solid liquid separation in a CCD circuit. However, flowsheets for separation and purification of the nickel and cobalt diverge markedly. The existing plants have been commissioned with varying degrees of success, with a variety of problems ranging from materials of construction to inadequate design. While the process problems are not insurmountable, there is much room for improvement. Currently there are several new HPAL plants at the feasibility or financing stage. All of these have adopted one of the existing flowsheets. Most of the enhancements have focused on increasing autoclave size. It is now time to assess the success and failures of the three existing plants and incorporate this experience in a design for productivity, efficiency and reliability. Towards this end, this paper discusses aspects of flowsheet optimization, materials of construction and engineering design.

Jan 1, 2001

By G. L. Spencer

There is no question as to the importance of the part played by the retort in modern zinc smelting. A satisfactory retort should have properties that will result in resistance to slagging action and fire cracks, and have no tendency, or at least only a small tendency, to soften and bend under furnace heat. The life and cost of a retort also are extremely important factors. The trend in zinc smelting during the past few years has been toward longer retorts and .higher charge density. This is caused by the fact that the diameter is limited to 9 or 10 in. because of heat penetration difficulties in larger sizes. Consequently, increasing the length of the retort and density of charge offers the only practical means of increasing the amount of zinc produced per retort. The stiff-ness of a retort perhaps is the most important factor, as slag accumulates in the bottom of a retort which has sagged and very quickly cuts through, often ruining the retorts below. The development of the high-silica retort is a result of the demands made by the trend toward heavy charges. Materials Used for High-silica Retorts The materials used in the manufacture of high-silica retorts at East St. Louis are fireclay, grog and silica flour. Analyses are given in Table 1. The fireclay comes from the St. Louis district. The grog consists of clean firebrick culls, and the silica flour, a very high-grade material, is purchased in the form of a flour that has been ground through 140 mesh.

Jan 1, 1931

A paper presenting an overview of legislative and best practice approaches to the management of OHS&E and business risk for Australian tunnelling operations. Best practice can be achieved in Australian tunnelling through ærisk awarenessÆ by decision-makers and line personnel. This will identify problems before they occur and lead to implementing controls appropriate to avoiding loss throughout the life cycle of the underground opening. The author draws on legislative approaches from all Australian states together with practical experience from risk management and risk engineering work from six recent tunnelling projects. This describes a process that:commences with concept risk assessment,involves quantification of major hazards,conducts assessments of operating risks, andleads to implementation of an integrated management system that keeps construction activities connected with the controls identified in the design and planning phases and minimises the losses sustained as a result. Key points addressed include:where the industry is going with respect to risk û methods and considerations,how tunnelling risks are perceived by the industry and legislation,how tunnel constructors and owners can minimise exposure by using proper risk engineering ætoolsÆ, andreflections on best practice methods for transferring knowledge from designers to contractors/operators.

Jan 1, 2008

By Rodolfo Espinosa

"Industrias Peñoles, S.A. de C.V. in Mexico, has nine mining operations, six managed by Peñoles (base metal mines) and three managed by Fresnillo plc (precious metal mines). Seven of the operations use flotation and the other two are heap leach operations, one for gold and the other one for copper.This paper gives a brief introduction of Peñoles, shows mine locations and describes the main process characteristics of each concentrator. It also presents four of the new operating practices that were implemented over the last four years to improve the economics of the mining operations. These include (1) the use of centrifugal gravity concentrators to increase the recovery of gravity recoverable gold (GRG) and silver (GRS), (2) the use of expert systems to reduce process variability while increasing grades and recoveries, (3) the application of the Six Sigma methodology to key projects to ensure success and personnel development and (4) the use of water chemistry fundamentals to identify chemistry problems and design adequate solutions for improving grades and recoveries.INTRODUCTIONPeñoles was founded in 1887. It is a mining group with integrated smelting, refining and chemicals producing operations. Peñoles is the world largest producer of refined silver and metallic bismuth, the leading Latin American producer of refined gold and lead. It is amongst the world leading producers of refined zinc and sodium sulfate.Peñoles operates and controls six underground mines in Mexico and is the largest producer of zinc and lead of the country. It also produces copper concentrates and cathodes. Through its 77.1% equity stake in Fresnillo plc (a London Stock Exchange listed company); Peñoles is also a significant producer of gold and silver. Fresnillo plc operates three precious metal mines in Mexico. While Fresnillo is the world largest primary silver mine, Ciénega and Herradura are two leading gold mines of Mexico. Figure 1 shows a map of Mexico indicating the locations of the Peñoles mines. The main process characteristics of each concentrator are listed in Table 1."

Jan 1, 2011

By C. I. Pierce

Knowledge of the water content of oil-bearing formations is important in petroleum-reservoir evaluation work. Electric logging provides a means for making reliable estimates of water content if resistivity-saturation relationships representative of the formations are available. Relationships can be determined in the laboratory by a number of methods. This report describes and presents results of a laboratory investigation conducted at the Bureau of Mines Appalachian Experiment Station, Morgantown, W. Va. (1) to evaluate an evaporation method of attaining water saturations in sandstone samples when determining resistivity-saturation relationships and (2) to compare saturation exponents derived from data obtained, using different methods of achieving water saturations. A series of tests was conducted to determine the effect of evaporation on salinity distribution within the core specimen. Results of these tests show that a zone of high salinity was set up at the surface of a sample during evaporation and that long periods were required for the sample to reach resistance equilibrium after evaporation had ceased. Equilibrium time ranged from several minutes to several days, depending on the sample size and the technique used. The high-salinity zone was removed from the sample by using auxiliary porous material in capillary contact with the sample surface during evaporation. Salinity determinations and resistance measurements indicate that, at saturations greater than the minimum interstitial values, the mechanism of flow during evaporation was one of moisture migration mainly as a liquid from the interior of the test specimens to their exterior surfaces. The concentration of the contained brine remained essentially unchanged, except for a narrow zone near the evaporating surfaces.

Jan 1, 1958

By S. S. Clarke

THEN sufficient ore has been blocked out on a lease to warrant a shaft, the proposed. Location of the shaft should be carefully considered, as the old promoter's method of sinking wherever his hat landed is a sad mistake as some: of us have learned by trying to operate such mines. In some instances certain conditions exist, such as mill location, railroad right of way, etc., that necessitate a change of location from the. ideal, but under average conditions and with the knowledge of the formation gained from the drill logs and with the general trend of the orebody known, the shaft can be located from. the standpoint of its future relation to the mine with re-gard to hauling and' hoisting a maximum tonnage: at a minimum cost per ton, also taking into account the minimum amount of expense and trouble- in sinking. Quite a few shafts are located in the wall of a run or just in the thin edge of the orebody: As a general rule the formation here is solid and permits rapid and safe sinking, and the shaft pillars are left in practically valueless material. This permits the withdrawal of pillars and still keeps the shaft protected. By opening a shaft in thin ground, you are not tempted to cut it high, wide, and handsome, but to shape it up-with ample clearance for lay-bys and with more of an idea of permanency, as a few hundred extra dollars spent around the shafts for proper track installation will re-turn, a good rate of interest in ease of handling "cans," quick get-away; and fewer wrecks. Nearly all the shafts in this district are sunk on a contract basis, the con-tractors furnishing all labor and explosives, and the company building the sinking-derrick, dump-track, and furnishing, all equipment, material, and power. The following costs are the averages, for three shafts sunk through good solid formation, with no water to, contend with, and approximately 260 -ft., deep, having about-100 ft. of shale. The contract price was $9 per foot with the shale and $13 per foot in the solid, making a total of $2,980 paid to the contractor. The wages paid by the contractor were, $5 per shift for the hoist-man, who also sharpened steel, $6 for the lead shaft man, and $5 for the helper;, the cribbing was sawed on contract for 40c. per shaft: foot; about. 94 board feet. of cribbing was used per foot of staggered cribbing and 168 board feet per foot of solid cribbing.

Jan 8, 1928

By Abner Dixon

INTRODUCTION. IN India the production of mica, which in other countries is of very minor importance, is one of the staple, long established industries, and ranks high in the statistics of mineral products. Nearly two-thirds of the mica of commerce comes from India. The Indians have used mica for glazing and decorative purposes through many centuries. About 14,000 men are employed in and about the mines, and the indigenous and primitive mode of mining is still followed; but, by reason of the exhaustion of the surface supply hitherto won without intelligence or capital, it will not be many years before the present interesting and casual methods will be replaced by a less archaic and more profitable system. India on the whole has little mineral wealth, but the unique resources of its mica fields, cheap labor, and favorable natural conditions render it unlikely that any other country can ever more than temporarily contest her leadership in the production of this one minor but essential mineral. Mica plays a small but indispensable role in a variety of fields of dissimilar application. Its use and value depend upon characteristics which different kinds of mica have in varying degrees, each kind being adapted to 'its own special purpose. Its well-known characteristics of transparency, flexibility, elasticity, toughness, high dialectric, strength, perfect flatness; ease of splitting into thin films, ability to stand high heat and sudden changes in temperature, give it value in many industries. No other substance, natural or artificial, has this combination of qualities. The oldest use of mica is in glazing. By reason of the improvements in annealing glass, this is not now of great importance, but mica is still employed for the covers of ikon images in Russian churches, the windows of anthracite stoves, compass

Jan 5, 1913

By Robert A. Haney

During the last ten years, longwall mining systems have undergone many changes. Panel widths and lengths have increased. Longwall faces have become more automated. Average production from individual longwall panels has increased from 1,000 to 3,600 tons per shift. To control the dust generation resulting from the higher production, longwall dust control systems have integrated various dust control techniques. Systems designed to control dust generated at the crusher/stageloader, shearer, and supports are common to most longwall faces. A survey was made of the dust controls that are currently in place on all the longwalls in the U.S. This survey addressed the types of controls used to reduce dust generated at the crusher/stageloader, shearer and roof support movement. Additionally, information on face ventilation rates, cutting cycle and level of automation was obtained. The purpose of this paper is to review the dust control practices that have been implemented throughout the United States and to identify those controls that are being used on high production longwall faces. Additionally, a model is used to demonstrate how ventilation and automation affect occupational exposure. Automation of roof support movement can offer some of the greatest reductions in occupational dust exposures. While technically feasible, its full benefit has not been fully realized by the industry. Until technology to fully automate longwall mining systems becomes more reliable, future dust control systems must rely on increased ventilation, application of headgate dust collectors, improved shearer dust controls and improved shield dust suppression systems.

Jan 1, 1995

By Newell Hamilton

Some years ago, in the manufacture of seamless tubing from an alloy steel containing 0.07 per cent maximum carbon, 18 per cent chromium and 8 per cent nickel, at the plant of The Babcock & Wilcox Tube Co., a peculiar type of piercing defect was noticed. This defect was definitely associated with certain heats of the alloy and was independent of any of the variables of mill operation and billet-heating condition. A thorough analysis of the defective material yielded but one clue to the reason for its abnormal behavior in piercing and that was its oxygen content as determined by the vacuum fusion method. The oxygen content of the defective 18-8 alloy was found to be from two to three times that of the material that had pierced satisfactorily, and this incited an active interest in the vacuum fusion method for the analysis of alloy steels. After a critical survey of the literature on this subject, and considerable experimentation, an apparatus and technique were evolved that gave a fairly rapid, simple and reliable method of analysis. Samples selected from six years of tube production of 18-8 and other corrosion-resistant alloys were analyzed by this method. This paper describes the procedure and gives a correlation of the oxygen, hydrogen and nitrogen contents of a number of alloy steel samples representative of good and bad tube-piercing quality. The Apparatus Basically the apparatus used in this work was that of Jordan and Eckman,' employing a high-frequency induction furnace and the gravimetric method of analyzing the evolved gases, nitrogen being excluded from the determination. In addition, a magazine-type cap and a large-

Jan 1, 1934

Milling circuits are known to be difficult to control. In order to address these difficulties, it was decided to develop and test a model predictive controller (MPC) for a milling circuit. A milling simulator was written using Microsoft Visual C++ and used to design and test the MPC controller. Due to the large number of tuning parameters in a controller of this type, an optimizing algorithm was written that automatically tunes the controller. Good, robust control was obtained when the controller was tuned using this algorithm. Control was further improved by combining feedback and feed forward control and by using quadratic programming in the MPC algorithm. The movement of the manipulated variables was reduced by using a novel technique that allows the controlled variable to vary within a specified region around the set point. An optimiser controller was also successfully implemented to control the circuit at its maximum throughput.

Jan 1, 2000

By Lucien Eaton

The use of filling in mines is less common in the United States than it is in Europe, where in some places it is required by law. In most cases the filling is placed by hand, and the material used for this purpose is the waste from development and that sorted from the ore in the stopes. When these sources provide an insufficient supply, additional rock must be quarried on surface or mined underground, or some other material must be used. In different parts of the world sand, clay, gravel, culm, granulated slag, mill tailings, and even ashes, have been used as filling material in place of or in conjunction with rock. Of all the materials used for filling the best is probably clean sand. Gravel, finely crushed rock, granulated slag and coarse mill tailings are almost as good, and the methods used for placing and confining sand will apply equally well to any of these. The advantages of sand are its comparatively slight compressibility and the ease, economy and convenience with which it may be placed. On account of the voids, which necessarily occur in fills made of coarse waste, such fills will compress 10 to 25 per cent before they develop their full strength, whereas clean sand seldom compresses more than 5 per cent. Sand is especially desirable when practically complete filling is required, and sand derived from mill tailings, especially when not thoroughly cleaned, has been remarkably effective in sealing off and extinguishing mine fires. When natural sand is available on surface, or when it can be obtained from the mill tailings or tailings dump, the cost of using this material for fill will probably be considerably less than that of rock. In this paper it is not proposed to discuss all methods of filling, but to describe some of the methods used for placing sand fill and to make a brief comparison of their merits. Methods of Placing Sand Sand may be transported and placed underground by several methods, which may be classified as follows: 1. By Hand.—The sand, which must be comparatively dry, is taken down the shaft in cars on cages and is distributed to its destination in these cars, or it is dumped down raises and is drawn off and distributed by means of cars, wheelbarrows or scrapers.

Jan 1, 1932

Discussion of the paper of MANUEL EISSLER, presented at the New York meeting, February, 1915, and printed in Bulletin. No. 9.5, November, 1914, pp. 3661 to 2703. J. W. RICHARDS, So. Bethlehem, Pa.-I do not see in the paper a description of the Mabuki hearth as used for ore smelting. I noticed it described for concentrating matte, but I believe the older Japanese process was to use it for-smelting directly, by a pyritic smelting and Bessemerizing all in one operation, in the same simple hearth apparatus. There is a monograph published in German, on Copper-Ore Smelting in the Mabuki Hearth. At Ashio the practice of injecting bituminous coal at the, tuyères is noteworthy. It is very interesting to see two men load little cartridges on the end. of an iron rod with bituminous coal, and push them into the furnace tuyères, and with a piston inject 2 or 3 lb.. of bituminous

Jan 5, 1915

By WALTER S.

(New York Meeting, February, 1912,) THE earliest example of attempting to form finely-divided materials into larger masses for better adaptation to commercial use was probably the briquetting of peat and lignite-waste at Paris by the use of a clay binder. It was from this attempt that our word briquette has arisen (Fr. la brique), the formed masses being shaped similar to ordinary bricks. This term does not, however, lend itself to the many shapes of such formed material as are now being produced, as few of them aside from some of the European brown-coal products bear any resemblance to the shape of that well-known article. The term "agglomeration " has therefore been chosen as more accurately descriptive of the products now being manufactured, this term including the molding as well as the sintering. With the increasing prices of fuel and ores and the greater demand for economy in the operation of industrial plants, more ,attention has been paid in recent years to the utilization of waste products and low-grade ores and fuels. Much of the waste has been occasioned by the inability to utilize finely ,divided ores and fuels in the furnaces because they could not be kept there, or else because they clogged up the furnace-shaft so that gases could not be forced through under ordinary conditions of operation. As a result, all such fines were thrown on the dump. Again, with the exhaustion of the richer deposits of ores, concentration of lower-grade ores becomes a necessity, and most concentrates are produced in a finely-divided condition. Aside from these considerations, there is also the economy in the cost of operating the plant; a furnace running on agglomerated material will have a much greater output than one working on fines. In one instance the charge of an iron blast-furnace was changed from fine concentrates to briquettes and the output was increased four-fold; better results could have been obtained had facilities been at hand for taking care of the increased output.

May 1, 1912

By M. J. S. Innes

Abstract This paper is an account of an investigation made by the Dominion Observatory with a gravity meter and magnetometer over sulphide concentrations at East Sullivan, Val d'Or, Que., in June, 1947. The topographic relief over the area does not exceed 20 feet. The overburden varies from 0 co 50 feet. The west orebody had been outlined by extensive drilling. The average density contrast between the sulphide body and surrounding rocks is 0.5. Two hundred and sixty gravity and one hundred and ninety magnetic stations were observed. The results are shown on contour sketches. A derailed account is given of the methods employed to reduce the gravity observations. The survey shows that both gravimetric and magnetic methods are useful in delineating sulphide deposits under the conditions in which they occur at East Sullivan. The results indicate that the buried contact of the syenite intrusive southeast of the orebody could be traced with the gravimeter and chat the magnetometer was of little value for that purpose. Gravity anomalies due to the varying depths of overburden are negligible as compared to the magnitude of the total anomalies. Introduction The project was first suggested at a meeting of the Associate Committee on Geophysics of the National Research Council in September, 1946. At that time it was pointed out that the accuracy and speed of operation of the new gravity meters made them of special importance for geophysical prospecting and it was highly desirable to have an objective test of the performance of an instrument of this kind in delineating an orebody of known dimensions and density characteristics. Several years ago, a private company did some work with a gravimeter over the Amulet deposits, near Noranda. Unfortunately, the topography there is rather rugged, with hills and ravines exceeding 100 feet, so that the topographical effects rendered it impracticable to distinguish between anomalies due to the sulphides and those due to surface irregularities. An orebody of a typical nature, where the disturbing topographical corrections were not excessive, was therefore sought.

Jan 1, 1949

To reduce air be respirable dust generated from emptying dry dust collectors on small truck-mounted drills used at surface coal mines.

Jan 1, 1995

By Robert Hopler

THIS paper deals specifically with heading-driving as distinguished from the broader term tunnel-driving. A heading is a pilot or path-finder for the main tunnel. Some headings are complete tunnels in themselves; that is, conditions at times warrant driving a heading the full diameter of the proposed tunnel. A tunnel 10 ft. in diameter might be driven to advantage through a single heading, provided the nature of the material admits, but it usually pays to drive rock tunnels of large diameter through the headingand-bench system. Much depends upon the material, as in soft ground tunnels of much larger diameter are driven in a single heading.

Jan 1, 2010

The United StatesÆ reporting standard for the mining industry for securities purposes is contained in the Security and Exchange CommissionÆs Industry Guide 7. It defines proven and probable Reserves using its own definitions, and prohibits the disclosure of quantitative estimates, for all mineralisation other than those two Reserve categories (though disclosure of Measured and Indicated Resources as quantitative mineralised material estimates is now informally allowed). Similarly, it restricts disclosure of value estimates to Reserves only, which SEC policy generally requires to be on an historic cost accounting basis. The SEC does not maintain a formal Competent or Qualified Person policy. In March 1999, the US-based Society of Mining, Metallurgy and Exploration (SME) released an update of its 1991 guidelines for definitions to be used in reporting of Mineral Resources, Reserves and Exploration Information, closely abiding by the 1997 CMMI recommendations. However, without SEC recognition, reporting under the SME and CMMI definitions is effectively barred for US companies. The SEC intends to adopt the International Financial Reporting Standards (IFRS) of the International Accounting Standards Board (IASB). This will occur within just a few years, when the convergence project for development of the IFRS has reached a satisfactory point. The US is the largest financial supporter and participator in IASB. The Extractive Industries Standard of the IFRS will likely terminate Industry Guide 7. However, the effect of this international replacement will likely be equally restrictive. This could possibly neutralise the benefit of a CMMI-based global reporting standard. SME, the US society encompassing the widest range of mining industry professionals, does not have a Code of Ethics. It has no mechanism for requiring members to abide by a professional standard. SME is presently looking into possible solutions for this deficiency. US-based professional societies that do have a binding Code of Ethics, generally cater to a single profession, and are not just mining industry related. The American Institute of Professional Geologists (AIPG) and the American Institute of Minerals Appraisers (AIMA) are examples. The SME is considering creating a subsidiary body with an enforceable Code of Ethics. To support a CMMI-based global reporting standard, competent persons will need to work across international borders. A standardised mechanism for qualifying and registering competent persons will be needed. National rules and laws must allow competent persons to easily enter countries to perform their work. State issued licenses are increasingly required for much of the work performed in the US mining industry by engineers, geologists and minerals appraisers (valuers). Such licenses are not required by the SEC for Reserve reporting in the US, may not be required for valuation of mineral properties under certain circumstances, and except for real property valuer licenses, they generally do not have a binding code of conduct. However, state licensing of professionals forms a substantial and increasing barrier to interstate trade in professional services, and can be a prohibitive barrier to professionals from outside the US. Any rationalisation of this confusing patchwork of regulations confronting US minerals industry practitioners will only occur as part of larger, national change, hopefully aimed at compliance with international standards and protocols. The US does not have a valuation standard aimed specifically at the mining industry. The Uniform Standards of Professional Appraisal Practice, the national valuation standards, often must be applied to mineral property valuation, but contains no specific instructions for minerals. The author has campaigned against development of minerals valuation standards proposed by US minerals institutes. Instead he encourages the mining industry worldwide to place its support behind the initiative of the International Valuation Standards Committee (IVSC) to include an extractive industries section in its International Valuation Standards (IVS). This should provide a global set of valuation standards for the mining and petroleum industry within two years. This addition to IVS will provide essential valuation standards reference support for the extractive industries financial reporting standard of the International Accounting Standards Board. The IVS has achieved a high level of acceptance in the developed and lesser developed countries of the world. It provides a comprehensive framework of Generally Accepted Valuation Principles for the valuation profession internationally, for valuation of all property or asset types. IVSC is effectively a sister organisation to IASB. The IASBÆs International Financial Reporting Standards (IFRS), previously known as the International Accounting Standards (IAS), reference and quote IVS in some instructions for determination of fair value. IVSC is a non-governmental organisation (NGO) member of the United Nations and maintains liaison with many important international economic, accounting and financial agencies, such as the OECD, IMF and WTO.

Jan 1, 2002

By S Roberston, G Batt, R Shanahan, B Shah, A Trench, H Bromfield

The geographic imperative of ore systems leaves mining, more so than virtually any other aspect of modern industry, heavily dependent on obtaining and maintaining social licence to operate. A prospective miner cannot arbitrarily walk away from a deposit in search of more favourable community perceptions – concentrations of mineral endowment represent highly specific and fixed elements of the landscape, and their development and extraction thus requires the acceptance and trust of a specific network of landholders and stakeholders, sometimes with diverse and even competing interests in the development and use of the local environment. Weakness or absence of such social licence can bring added costs and complexity to developing and operating a mine – and in extreme cases even result in project failure. Because it must be maintained throughout the life of a project, such social risk becomes a substantial part of overall project risk profile, particularly during routine operations once initial technical and development risks have been largely resolved.CITATION: Bromfield, H, Roberston, S, Shah, B, Shanahan, R, Trench, A and Batt, G, 2018. On equitable distribution of mining wealth and the social licence to operate imperative – an African case study, in Proceedings Complex Orebodies Conference 2018, pp 6–7 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By Y. Okahara

The chlorination behaviors of pure iron and manganese oxides were investigated by combining a thermogravimetric analysis (TGA) technique with batch-boat roasting followed by leaching. Ferrous and manganeus oxides could be chlorinated readily, but, in the absence of a reductant, the higher oxides of both iron and manganese were difficult to chlorinate. Thermogravimetric analysis curves were drawn to illustrate the complexitites of the reactions, and the possible mechanisms were discussed. Then three manganiferous materials from the Cuyuna Range of Minnesota were treated by a process involving the selective chlorination of manganese followed by leaching. The results were interpreted in the light of the chlorination mechanisms observed on the pure iron and manganese oxides.

Jan 1, 1969