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By E. H. Griswold, C. E. Beecher

DURING 1931 the petroleum industry has faced the most hazardous periods of its existence, caused by large potentials, overproduction, and demoralized markets. Two state governors actually resorted to the use of the militia in an effort to restore a semi-stabilized condition within the industry, to prevent waste of the states' natural resources, and to restore prices to a level that would yield the states a reasonable tax revenue. These conditions have made it necessary to put into effect most. stringent economies and have produced a spirit of cooperation between companies to an extent that never before existed. The necessity for unified action on such matters as proration and the advantages to be gained by unit operation are being realized by the oil industry as a whole. Fewer wells have been drilled and wildcat operations almost eliminated: development and operation costs have been greatly reduced and more attention is being paid to efficient recovery methods. The net work of oil pipe- lines has grown rapidly especially in the area of East Texas. The construction and operation of natural gas and gasoline pipelines into areas far distant from the source of supply has been one of the outstanding accomplishments. Refining efficiency has continued to increase and the public is being supplied with a better grade of gasoline at a lower price. The unreasonable tax which state politicians have succeeded in placing on gasoline has encouraged tax evasion and unfair competition by un- scrupulous dealers and has misled the public as to the true price of gasoline.

Jan 1, 1932

By J. Forwood

The Youga gold mine in Burkina Faso, West Africa, is scheduled to produce first gold in the third quarter of calendar 2007. The project is expected to produce 540 000 oz of gold over 6.5 years, from a conventional open pit carbon in leach mine. The direct capital cost of the project is US$47 M. Etruscan Resources Inc, a Canadian based gold exploration and development company, holds 90 per cent of the project company Burkina Mining Company SA (BMC). The state of Burkina Faso is free-carried for the remaining ten per cent of BMC. RMB Resources Limited, of Melbourne Australia, has arranged a US$35 M project finance facility for BMC (the Borrower) as the majority of funding for the Youga project development. The loan facility was provided by RMB Australia Holdings and Macquarie Bank Ltd (the Lenders) each as to 50 per cent in the lending syndicate. The Lenders also provided a gold hedging facility to guarantee a minimum price for the project's gold production. Burkina Faso is a francophone country, part of the Economic and Monetary Union of West Africa (UEMOA). The project financing is the first such facility to be arranged for a mining project in Burkina Faso, with little or no precedent available in other UEMOA countries. Therefore, while the Youga gold project is forecast to be a robust project applying conventional mining and processing methods, a number of legal, technical, commercial and social issues required identification, evaluation and resolution before the loan could be established. This paper describes that evaluation process and the resolution of these issues. In-house experience and expertise in both the Lenders' and Borrower's teams has facilitated a greater understanding and `ownership' of the issues and hence provided comfort with risks which might not normally be taken in conventional project developments and project financings. As a result, blanket external reviews were not required by the Lenders. A long-standing relationship between Etruscan and RMB Resources also facilitated solutions to a number of issues. Nevertheless, a degree of flexibility by the Lenders, the Borrower and Etruscan was required to successfully close the financing.

Jan 1, 2007

By T. T. Ni

FOR MORE THAN 200 years, the Kochiu district of Yunnan province has been, and it still is, the hub of China's tin industry. The district produces annually from 80 to 90 per cent of that country's out-put of tin, which averages about 9,300 tons a year and places China fifth among the tin producing nations of the world. The tin ore reserves of the country are estimated (1) at 1,873,370 metric tons, of which 1,500,000 tons are in the Kochiu district. The mill of the Yunnan Consolidated Tin Corporation, described in this paper, is the only one of its kind in China. MINING AND SMELTING There are only two tin mines in the Kochiu district operating with modern equipment -the Hsin-Chang and the Lao-Chang, both owned by the Yunnan Consolidated Tin Corporation, a government company. The Hsin-Chang mine has four working levels with cross-cuts 6 ft. by 6 ft. and is equipped with steel mine cars and trucks to haul the ore. The ore is hoisted to surface in a three-compartment shaft and transferred to the mill by a 4-kilometer aerial tram. The Lao-Chang mine has two circular shafts 656 feet apart, each equipped with two cages. Haulage-ways 1,600 meters and 1,000 meters long, respectively, have been driven to the southwest from these shafts and are connected by three cross-cuts.

Jan 1, 1951

The paper describes the 209 in. single stage axial flow mine ventilating fan which commenced operation at The Zinc Corporation Limited, Broken'Hill, N.S.W., in January, 1954.This fan is used to ,ventilate the underground workings of The Zinc Corporation Limited and New Broken Hill Consolidated Limited and, at the time of installation it was the largest fan of its type in the world. It has amaximum capacity of 900,000 c.f.m. at 4·2 in. watergauge and is equipped with adjustable pitch blades and a novel form of variable speed drive.The considerations which lead to the adoption of this particular design are outlined, and a full description of the contruction and installation of the fan and auxiliaries is given.Comprehensive acceptance tests were carried out on the completed installation and, the testing procedure is described in detail. The results of sound level measurements are also included. A brief report on the performance during the 12 month period from 1st July, 1954, to 30th June, 1955, is then given.SELECTION AND DESIGN OF FANGeneral ConsiderationsBecause of the economic advantages of joint ventilation of the underground workings of The Zinc Corporation Limited and New Broken Hill Consolidated Limited, it was decided, after a full review of the future ventilating requirements of both mines, to sink a 20 ft. diameter circular upcast airway on the common boundary of the two properties, to handle a maximum quantity of 900,000 c.f.m.The anticipated air requirements were at this stage estimated to be:(a) initially 700,000 c.f.m. through a mine equivalent orifice of 160 to 2'40 sq. ft. (equivalent total pressures being 2·70 in. w.g. and 1·20 in. w.g.) ;

Jan 1, 1956

By W. Geo. Waring

Introduction THE winning of zinc and lead ores from the comparatively shallow deposits of the Joplin district, presents, few such problems for the mining engineer as are encountered in deep ore mining and in the handling of complex ores. However, for those who are interested in the origin and nature of ore deposits in general, there is much here to investigate, and upon studies in this direction will depend in no small measure the future of an industry that has produced during the year 1916, in southwest Missouri, lead and zinc ores to the value of $26,319,383; adding $46,022,164 to the metallic wealth of the nation. Including the adjacent mines in Ottawa County, Oklahoma, and Cherokee County, Kansas, which are, really continuations of the Joplin district, the total value of ores produced reached the sums of $34,089,503, and that of the metals, $58,927,941.1 The ores produced in the Joplin district are remarkable on account of their almost uniformly high" metal content in both lead and zinc. Their superiority in this regard is unparalleled, and is doubtless clue to certain geological conditions that are now possibly explicable, provided that the artesian circulation = ascension hypothesis of the origin of the ore deposits is proven beyond question to be the only tenable explanation of the facts. These, as well as other valuable zinc-ore deposits, are bound to he exhausted in time, for ordinary mining purposes, acid it concerns the mining engineer that the conditions under which ores of this character were actually deposited in the form in which they occur, may, if possible, be ascertained, in order that he may learn where to look for similar deposits in other regions, or even how to reproduce artificially such condi-

Jan 9, 1917

By M. J. Collins

Direct pressure leaching of zinc sulphide concentrates was started? commercially in October 1980. Continuing research and development studies at Sherritt and feasibility studies for a number of clients have defined various pressure leach configurations for integrattons with existing roast- 1 each operations and for grass roots plants. Existing and potential applications of zinc pressure leaching are discussed.

Jan 1, 1990

Plant based on the New Jersey refluxing process was installed at the Cockle Creek Works of Sulphide Corporation Pty. Ltd. to refine portion of the zinc output from the Imperial Smelting furnace.Refining of impure zinc is effected by distillation in two stages in vertical columns comprising a series of superimposed silicon carbide trays designed such that ascending zinc vapours and descending liquid metal are in intimate contact. In the first stage, portion of the zinc and its cadmium content are distilled from impure feed metal, condensed, and while still molten, fed to the second column in which zinc is boiled under controlled refluxing conditions to remove the cadmium content.The resultant zinc has a purity in excess of 99·995 per cent zinc.The availability of refined zinc has made possible the production of a number of zinc alloys for marketing in addition to the basic grades of zinc.

Jan 1, 1970

The æMountain Camp reefÆ at Alford's mine, Wakamarina,Marlborough, had no recorded gold production although assays of 5 - 26 g/t were reported, but it did produce c. l000 kg of scheelite. The lode consists of a lower massive quartz layer, and upper, cm-banded, ribboned quartz layers, and has a very low sulphide content. Within the massive layer, relict early fine-grained mosaic quartz with idioblastic scheelite is surrounded by recrystallised granoblastic coarse-grained quartz with calcite and plagioclase, in which an original ribbon banding texture is mimiced by strings of tiny inclusions. In both the banded and massive layers, rounded quartz grains, created by cataclastic milling of grain margins and along syn-vein fractures, have been partially annealed within later quartz overgrowths. Late fibrous quartz and calcite fill brittle cross fractures.   Deformation events D1 and D2 are associated with mid-late Jurassic metamorphism of the Pelorus Group, D2 producing the main regional schistosity (S2, and the earliest scheelite. D3 is an extensional mylonitic shear event that formed the dominant schistosity in Alford's mine (S3). The quartz lode was emplaced within the mylonite by a series of individual dilation pulses (D4). The D5 event caused crenulation of the S3 mylonite, kink banding and chevron folding of the S2 schist and S3 mylonite, and reverse faulting, rodding and cross-fracturing with late fibrous quartz-calcite veining of the D4 quartz lode.   Fluid influxes during successive dilations of D4 fractures progressively caused recrystallisation of earlier quartz bands on the footwall, annealing and recrystallisation of quartz along milled crystal margins and fractures, and deposition of minor sulphides. There was thus a dynamic interplay between fault dilation, lode fracture, fluid influx, lode band deposition, and lode recrystallisation. Illite-Kfeldspar al ¦ 2 Ma (K/Ar), c.30 Ma after metamorphism.

Jan 1, 1996

By Jon Pocock, Ashma Singh

The traditional approach for the beneficiation of South African siliceous sedimentary phosphate ores has been reverse cationic flotation. The robustness of this approach, however, has been a concern due to its sensitivity to parameters such as slimes content, headgrade ( P2O5 and SiO2 content), reagent dosages and conditioning times. The phosphate mineralisation for the ore body under investigation is predominantly carbonate fluorapatite composed of mainly quartz and apatite and minor amounts of chlorite, ilmenite and carbonates. Beneficiation of low grade sedimentary ores containing calcareous impurities, such as calcite and/or dolomite in addition to siliceous gangue, is required to meet the increasing demand; therefore, much research has been carried out to find an alternative technique to beneficiate this material. This paper investigates traditional flotation approaches versus the currently adopted ‘Crago Process’. Comparative results are presented in terms of upgrade potential for the production of concentrate rock for downstream applications. The novelty of the ‘Crago Process’ lies in its double stage approach, i.e. direct fatty acid flotation followed by reverse cationic amine flotation. The Crago process was able to achieve higher upgrades reporting at 32.1% P2O5 compared to conventional cationic flotation only achieving grades of 18.5% P2O5. Furthermore, the recovery gain was 3%.

May 13, 2023

By Jim Truskoski, Alain Bouchard, Andy Kerr, Germain Labonté, Jim Barrett

"Improving mill grade recovery relationships is always good business. INCO’s Clarabelle Mill has just undergone a $16 million process upgrade that was designed to improve nickel recovery by 2%. The “Mill Redesign Project” was completed on time, under budget and delivered the promised improvement in recoveries.This paper describes the methodology of the Mill Redesign Team, details of the process improvements and the critical success factors that helped the team deliver on its promises.With a payback of under one year, the Mill Redesign Project will play a key role in ensuring a competitive edge as INCO embarks on its second century of operation.INTRODUCTIONIt is not uncommon in milling operations to encounter a crisis. That is the point when the process does not behave as expected and fails to respond to the increasingly desperate efforts of the metallurgists and operators. Flowsheet and process changes are attempted and abandoned. With luck, one or more of the changes achieves some mitigation of the original problem or more usually, the original cause of the problem disappears. Regardless, the metallurgist can sit back and bask in the apparent success of his or her endeavours.Less common is when a problem is carefully diagnosed, a team put together to explore all avenues and recommend a path of action that is implemented on time, on budget and immediately delivers on the promises which are sustained over time. This is one such story. It is the story of the Mill Redesign Project at INCO’s Clarabelle Mill in Copper Cliff, Ontario.BACKGROUNDThe Clarabelle Mill was built in 1971 on the southern rim of the Sudbury basin. At that time it was one of four mills operated by INCO in the Sudbury area. During the 1970’s, 80’s and 90’s, the need for increased process efficiency, higher levels of sulphur rejection to tails and the concurrent development of high capacity mills and flotation cells, resulted in the consolidation of INCO’s Sudbury area milling operations into a single, expanded facility at Clarabelle."

Jan 1, 2003

By Thomas Lane Carter

THE history of mining in South Africa differs somewhat from that of other countries in the part taken by the aborigines in the development ?of the mineral deposits. The Spaniards in America, and the fortune-seekers of Australia and New Zealand, found large numbers of natives in these new countries, but the inhabitants did not become willing or efficient workers ill the mines which the white men started. The Kaffirs of South. Africa have not shown the same antipathy to labor, nor do they show any signs of dying out in the presence of the white man's civilization. They are a virile race, and so far the vices of civilization have not killed. them. While it is true that the brain and skill necessary for the exploitation of the mineral resources of this sub-continent-have been supplied by the white race, it is also a fact that most of the rough labor in the development of the mining industry of South Africa has been done by the Kaffirs. The Kaffir tribes differ greatly in their mental and physical capabilities. Compare, for instance, a Zulu of Natal with a Bechuana, or a Xosa of Cape Colony with some of the degenerate tribes of Central or East Africa, and you will find that they have little in common, save that their skin is black and that they do not believe in clothes. As a general rule, the tribe's in the milder, healthier climates are far superior, both in mind and body, to the Kaffirs brought up in the hot malarial sections of Central Africa; and it naturally follows that the black men from the temperate zones of the country, are much finer workmen than the degenerates from less favorable sections: It is universal in South Africa to speak. of the .Kaffirs as " boys." No matter if he is 90 years old, the Kaffir is always a " boy," and in this paper the word " boy " is synonymous with Kaffir.

Nov 1, 1908

Preliminary work being undertaken on the optimisation of decision strategies for an open-pit metalliferous deposit is presented. The Optimal Control method has been selected rather than the easier to implement Dynamic Programming method of optimisation since a fundamental criteria of Dynamic Programming is violated. Essentially a system of state equations and decision variables is developed for the operation under consideration.

Jan 1, 1984

By Rapheal Trousselle

For over 5 years, Davey Bickford has been developing and testing an electronic detonator blasting system. These new-technology detonators provide more accurate timing than conventional systems that rely on the combustion speed of a pyrotechnic composition.

Jan 1, 1997

By W. Bosmans

The European Commission published its Communication of the Thematic Strategy on the sustainable use of natural resources ("Resource Strategy") on 21 December 2005. The Resource Strategy aims at reducing environmental impacts associated with resource use - called decoupling - in a growing European economy and worldwide. The impacts of unsustainable resource use include e.g. climate change due to fossil fuel use, land use and environmental degradation due to mineral extraction and processing, or overexploitation of soil and fish stocks. To decouple environmental impacts from economic growth, a life-cycle approach is adopted. It means that the environmental impacts are taking into account at each stage of the life cycle of a resource, avoiding that negative impacts are shifted to other environmental media, to other stages of the life cycle, or to other countries. Key to achieving decoupling are three factors: - More value - creating more value while using fewer resources (?resource productivity?); - Less impact - reducing overall environmental impact per unit of resources used (through ?cleaner? technologies and consumption pat-terns); - Better alternatives - substituting currently used resources with better alternatives. The paper focuses on the implementation actions of the Resource Strategy in particular related to the minerals industry: 1. The Data Centre on natural resources; 2. Indicators to measure progress; 3. The involvement of economic sectors to take concrete actions; 4. EU Member States involvement, focusing on resource uses with the most significant impacts; 5. The International Panel on the sustainable use of natural resources, set up together with UNEP. With its 25 years time horizon and its wide approach the Resource Strategy will have a co-ordinating function to ensure enhanced coherence and efficiency. The challenge will be to integrate this approach into all policies and decision-making.

Jan 1, 2007

By Patrick R. Taylor

In the search for the development of more "environmentally friendly" and more intensive waste disposal approaches to meet more and more stringent environmental regulations, thermal plasma-based processes are considered one of the most promising alternatives to well- established technologies such as incineration. This paper presents an overview on the research and development status of thermal plasma-based waste remediation technologies. The properties of thermal plasma are described. Due to its unique feature of high-energy intensity and super high temperature, thermal plasma is particularly capable of destroying organic- containing wastes. Its potential and promising application to waste remediation may include: treatment of incinerator ashes; metallurgical dusts (especially, electric arc furnace dust); medical wastes; radioactive wastes; and other Resource Conservation and Recovery Act (RCRA) listed hazardous wastes. Many research institutes and vendors have been involved in the development of thermal plasma-based waste treatment technology encouraged by the cleanup programs supported by the Environmental Protection Agency (EPA), the Department of Energy (DoE) and the Department of Defense (DoD). More recently, thermal plasma-based waste treatment technologies (sometimes called plasma-enhanced pyrolysis) are focused more and more on not only just destroying organic wastes but also on how to practically, and economically recover energy contained in the organic waste materials in addition to the recovery of metals in order to offset the high operating costs.

Jan 1, 2003

By Ivan Imris

The iron production has generated many tonnes of very fine residues with high concentration of iron. In addition, during the recycling of galvanised steel scrap in the steel making processes the zinc and lead are largely concentrated in the dust. These kinds of dusts are usually dumped beside the metallurgical plants and cause environmental problems. Therefore the metal recovery from the metallurgical residues has become a major interest not only from the viewpoint of metals recycling but mainly from the viewpoint of environmental land protection. The thermodynamic analyses and laboratory experiments suggested that the metals could be recovered from metallurgical wastes by reduction roasting and by plasma smelting processes. The iron rich pellets with very high metallization may be obtained from metallurgical wastes by the reduction roasting and the inert slag and pig iron could be produced by plasma smelting processes. In both cases the iron rich products are suitable for the steel production. During the reduction roasting or plasma smelting the high volatile zinc and lead metals were removed and enriched as a secondary dust, Zn-Pb concentrate, which is suitable for processing in zinc and lead smelters. Suggested processes are commercially feasible and environmentally friendly without any solid or liquid waste.

Jan 1, 2003

By Nan Zhou, Jixiong Zhang, Qiang Zhang

"Mining activities under hard roof could easily induce rock burst. Based on the geological conditions of widespread hard roof in China, this paper discusses the type, mechanism of occurrence and prevention of rock burst caused by hard roof from energy evolution point of view. It analyzed the interaction between the solid backfilled body and roof under different backfilling ratios. And by establishing and applying the mechanical model, the deformation of hard roof and energy evolution of the panel under different backfilling ratios were determined, revealing the control effect of solid backfilling on disaster-causing energy. As a result, an innovative method using the solid backfilling method was proposed as a solution to the hard-roof-induced rock burst hazards. Moreover, mine trial was conducted in Panel 6304-1 of Jisan Mine. The result shows that the stress concentration factor of the front abutment stress was only 1.44; the coal dusts in drill holes didn’t exceed the limits and microseism of large energy didn’t occur during mining mining, indicating that solid backfilling mining could be applied as an effective method for preventing rock burst caused by hard roof.INTRODUCTIONSHard roof refers to the thick strata above the coal seam or thin immediate roof. It is strong with poor joint development. After mining, instead of immediate caving, it will overhang for a large area in the gob, resulting in high stress in front of the face and difficulty in gas dispersion. As a result, the face spalls, the roof exposes and the gas accumulates in the gob. With the continuing advance of the face and increase in area of overhang, the stress in the hard roof will eventually exceed its ultimate strength and cause a large area of caving, followed by quick release of energy concentrated in the roof and coal seam, which may cause rock bursts and other dynamic disasters in the mine as well as serious equipment damage and casualties. Therefore, the hard roof becomes one of the main factors causing rock bursts at the face.Hard roofs in China varies in conditions. It ranges from dozens of meters to hundreds of meters in thickness. However, coal reserve under hard roofs accounts for about 1/3 of the total reserve; moreover, nearly 40% of the fully-mechanized coal mining panels are those with hard roofs and more than 50% of the mining areas are associated with problems of hard roofs. Aiming at this problem, researchers at home and abroad have proposed many solutions, e.g. coal pillar support, strength weakening and forced caving, to prevent rock bursts caused by hard roof. These solutions have been employed in some cases with good results. However, due to the variability in geological conditions of mining and hard roofs, the application of the above solutions is limited."

Jan 1, 2015

By D. S. Choi

This paper presents a theoretical analysis of the effect of shape and size on strength of geologic materials. The results indicate that the shape effect is caused by the development of confining pressure at the interfaces. The linearization of the obtained formula is of the same form determined by experiments. The size effect is attributed to the fact that the geologic materials contain discontinuities in the form of fractures, bedding planes, and cleats. The maximum reduction factor for the size effect is the one-sixth power of the volume of a cubic test specimen. The results of this work are particularly useful in determining the strength of coal pillars in underground mines.

Jan 1, 1989

By Sharpin P. C

The countercurrent gas-solid heat transfer during the drying of brown coal briquettes in the pilot carbonization plant at Morwell has been analysed and theoretical gas and solid temperature distributions through the drier have been calculated. Although the calculations rest on several simplifying assumptions, the theoretical temperature distributions compare well with those observed in practical operation. Valuable conclusions are reached as to the effects of changes in drier operating conditions on the rate of drying of the briquettes which controls the strength of the char produced. The analysis shows why a limitation was reached in the improvement of char strength in the pilot plant in 1961 due to the performance of the drier and a prediction is made of a way in which the limitation could be overcome.

Jan 1, 1966

By Leonello Sciacca

Deepening of harbours has become a priority, necessary to the ongoing operation of the wharves in the face of deeper draft merchant vessels and cruise ships. It is now standard practice in many areas to provide for harbours to be dredged to significant depths below mean sea level, in the order of 12.00 m (39 ft) for existing berths and 15.00 m (49 ft) for new wharf construction. The Ravenna Port Authority initiated a project to deepen the harbour bottom at selected wharves to a depth of 12.00 m (39 ft). In preference to reconstruction of the wharves with longer and heavier sheet piling or other equally disruptive reconstruction, they identified the structural reinforcement of the existing wharves by means of deep underwater tie rods as a possible alternative cost-effective solution. Having defined the design concept, effort was concentrated on developing the required technology. A technique, already in use for the installation of tie rods by means of robotics, was identified as potentially suitable for underwater use. It was decided to carry out the fine tuning and the evolution of the technology for a marine environment of the robot unit and of the related remote control software that controls the installation of the tie rods. An experimental test site was set up to refine the drilling, installation, grouting, monitoring and testing of underwater tie rods. The purpose was to confirm the feasibility of the proposed solution and the reliability of these tie rods for use in the reinforcement and construction of wharves. The paper also discusses the theoretical and experimental study of underwater tie rods dealing with the theoretical analysis of the interaction between tie rod and soil, aimed at identifying the correlation between the forces of applied traction and the corresponding measured elongations. A series of tests were carried out with positive results, both at the operating load of 300 kN (67 kips) and at the nominal maximum load of 630 kN (142 kips). The tests were carried out on seven tie rods, of which three were installed at a depth of 5.00 m (16 ft), principally to test the reliability of the operating and remote control systems in the presence of a significant hydrostatic pressure, and four were placed at a depth of 8.00 m (26 ft) to check the load bearing capability of the tie rods positioned at the depth called for by the current project.

Jan 1, 2011