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By J. R. Thoenen

The objective of this circular is threefold: First, to describe briefly the various modes of occurrence of sand and gravel. Second, to emphasize the need for adequate prospect¬ ing and exploration prior to the expenditure of funds for development and plant construction. Third, to describe various methods of prospecting and exploration and their application to the several modes of occurrence of sand and gravel. Sand and gravel may be found in nearly every county or township in the United States. Commercial deposits, however, are by no means so widespread. The introduction of concrete and the consequent impetus given to consumption of gravel and sand aggregates has seriously depleted deposits in some congested areas. Increasing re¬ strictions in the specification requirements for marketing sands and gravels have further narrowed the economic areas. On the other hand, the combination of increasing transportation costs and decreasing selling prices has forced the decentralization of gravel production. As a result smaller, intermittently operated, and widely scattered portable or semiportable unit plants have been encroaching on the territory formerly supplied from centrally located pits with large tr.atment plants. Generally speaking, the small portable plant can not produce any great variety of ma¬ terials to as exacting specifications nor as economically as the large permanent plant.

Dec 1, 1932

By K. P. Pavlich

Strategic planning, including the process of developing competitive strategy, is an integral part of all organizational management; from one person operations to multi-national Fortune 100 firms. The structure of that process varies from decisions and direction based upon one person's intuition to the integration of multiple strategic planning groups from each of a firm's many business units. Everyone has heard interesting strategic planning stories such as the railroad industry's long term failure to realize that they were in the transportation business and not the railroad business, the decision to "give away the razors and sell them the blades", Caterpillar's "SOQ NaP" campaign (Sell On Quality, Not On Price), or the tanker industry's eventual realization that by better managing turn-around the firm could control their largest single cost: depreciation. It is important to remember that very few strategic planning decisions are going to become Harvard Business Review case studies. That fact does not, however, diminish the need for understanding the firm's business, and actively planning how it is going to remain in business in the future!

Jan 1, 1989

Retreating Cu-Mo Rougher Tailing by Flotation for Concentration of Copper and Molybdenum

Sep 13, 2010

By P. J. Noakes

Remote and isolated, located in a frigid, hostile environment, the Black Angel mine in Greenland had to create a warm social environment which would help attract and retain a stable work force of miners and support staff. The high cost of personnel turnover plagues many mines and, when the mine is inside the Arctic Circle, accessible by helicopters which are highly vulnerable to unpredictable weather conditions during the long, dark winters, the potential costs of personnel turnover become critical factors in the success or failure of the mining venture. Manpower planning should start from the date the engineers begin the technical design of the new mine. The plan should include provisions not only to ensure an adequate, skilled work force, but also to ensure a stable work force of people who are happy enough in the mining environment to want to remain, take their vacation and return to work at the mine. The skilled work force was assured with training courses of four months, designed to produce highly specialized underground workers from unskilled Danes and Greenlanders supported by trained Swedish and other Scandinavian miners. The stable social unit was assured by plans the primary attribute of which had to be flexibility. The accommodation changed from shared accommodation with communal washroom facilities to single accommodation with private washroom facilities. A recreational director was hired to help the workers make use of elaborate recreational facilities. A closed-circuit TV and radio system was installed to operate as a private broadcasting system using taped programs originally broadcast on European TV networks or developed by the mine personnel themselves. The liquor rules were changed and the mine manager became a licensed innkeeper responsible for the orderly operation of the Black Angel Bar in accordance with the Danish laws governing the services of a public bar. The result is a relatively stable work force. Some 35% of the people have more than two years' service with the company, Greenex A/S, and some 62% complete 10 months of service.

Jan 1, 1978

By E. J. Babcock, W. W. Odell

The Bureau of Mines since its establishment has always taken an active interest in the utilization of lignite and in the development of the lignite dep'osits of the United States. Extensive lignite fields occur in the west central States, notably in North Dakota, Montana, Wyoming, Colorado, and Texas; there are smaller areas in several other States, some of which are widely separated. The total area of the deposits and the total amount of lignite in these several districts are so enormous that the economic value is seldom recognized. To the people of ·the west and west central regions, however, the larger utilization of lignite, in whatever form it may be, is of fundamental importance, and any new methods or uses that promise to open these great lignite fields for more general and more efficient use deserve careful study. Although these lignite deposits underlie areas of thousands of square miles, their development and general utilization has been rather slow. This is no doubt partly because many of the districts are not thickly settled or highly developed in manufacturing industries, but is largely because lignites, from their peculiar physical and chemical characteristics, are low-grade fuels. Most of the lignites in these areas are imperfectly developed coals; many have a more or less woody structure; some belong to the brown-coal type; and others are darker, denser, and more homogeneous, approaching subbituminous coal. The people living in the regions in which these vast deposits occur, especially in the west central part of the United States, are vitally interested in every effort toward bettering lignite as fuel and aiding its wider utilization.

Jan 1, 1923

By R Thomson

The use of uranium metal in non-ferrous metallurgical practice is dis-cussed with reference to its alloying behaviour and chemical activity. It is suggested that the more promising applications are in the treatment of molten metals to combine with impurities. Mines Branch work along these lines is described for copper, zinc, magnesium, aluminum and nickel alloys. It is shown that a cop-per-uranium master alloy (25 per cent U) successfully deoxidizes molten copper without detriment to the electrical or mechanical properties of the product at residual uranium levels of up to 0.8 wt. per cent. Additions of uranium to alpha brass in amounts greater than the lead impurity content were found to remove the deleterious effect of lead on hot-workability. Similar deoxidizing and malleableizing effects were found with uranium additions to nickel. It is thought that uranium forms stable intermetallic compounds with many impurity elements. A significant malleableizing effect can therefore be expected in the presence of other elements besides lead.

Jan 1, 1963

By Luis Martín Tejeda

La simulación numérica es considerada como uno de los mejores métodos de modelamiento y planeamiento en la evaluación de la estabilidad de los taludes en minería superficial. En ese sentido, el presente texto señala que a través del método de tensión-deformación, implementado en programas computacionales basados en el método numérico de elementos finitos, se puede llegar a localizar la probable superficie de ruptura. Asimismo, con los diferentes modelos constitutivos como el elástico perfectamente plástico, estos taludes pueden ser evaluados. Por último, se describe brevemente los mecanismos de ruptura en taludes altos, el cálculo del FS y algunas características del programa de elementos finitos PLAXIS v. 7.2.

Sep 19, 2006

By Fritz J. Klingler

From site demolition, to design, to construction, Detroit's new Tiger Stadium project is required to be completed within a short 2 ½ years from award of the design-build contract. Such extreme schedule requirements together with somewhat difficult ground conditions at the site, resulted in several challenges in the design and construction of the deep foundation system for the stadium. During the geotechnical investigation, an intermittent water bearing sand layer was encountered overlying the hardpan at the site. As a result, some concern developed regarding the potential for collapse of caisson bells within this layer, as well as the potential for flooding of the caissons during drilling. Although sand and/or ground water was encountered within about half of the caissons, standard drilling and belling methods were used, and adverse conditions were controlled in almost all cases through expeditious drilling, inspection and concreting of the caissons. This paper will present a summary of the ground conditions, design and specification requirements, and construction methods used to successfully install the caissons for this project.

Jan 1, 1999

By Ellis S. Hertzog

The data published in this report cover only one phase of a special study of the physical and chemical properties of Alabama coals made by the Bureau of Mines. In addition to determinations of friability, the survey included determinations of grindability, B.t.u. value, end ash-fusion temperature. Assay distillation tests, both for high- and low-temperature carbonization, and proximate and ultimate analyses were made also. However, this preliminary paper is concerned only with the results of friability tests and is issued to expedite the release of this information to the public. The friability test measures the liability of a coal to break into smaller pieces when subjected to repeated handling, as occurs in the mining, preparation, and transportation operations. Friability depends on many physical characteristics of the coal that vary not only between different seams but also in the same seam. The laboratory methods of determining friability have been developed to give a practical means of estimating degradation of size. So far as is known to the authors, no data on the friability of Alabama coals have ever been published. This paper makes available for the first tine fairly comprehensive information on this subject. Because the procedure for the tumbler test for determining the friability of coal is relatively new to the coal operators, the authors have included a complete description of it in this report.

Jan 1, 1938

By D. P. Tao, J. G. Groppo, R. Killmeyer, W. W. Wen, B. K. Parekh

Economical dewatering of ultra-fine (minus 74 m) clean coal slurry produced in column flotation to a 20 percent or lower moisture level will be an important step in successful implementation of the advanced fine coal cleaning processes. The main objective of the present study was to evaluate efficiency and effectiveness of three dewatering techniques, namely, hyperbaric, vacuum and screen bowl centrifuge, in dewatering of ultra-fine (D50 ~ 25 m) clean coal slurry produced by the `Ken-Flote' columns operating at the Powell Mountain Coal Company, St. Charles, Virginia. he hyperbaric filter using 3 bar pressure and 165o cake formation angle, provided a filter cake with 23.6percent moisture with a throughput of 800 Kg/m2-h and air consumption of 868 Nm3/t (460 scfm/t). The vacuum filter with 30 percent submergence provided a filter cake with 27.8 percent moisture with a throughput of 122 Kg/m2-h. The screen bowl centrifuge provided a dewatered product containing 32.9 percent moisture at a feed rate of 450 Kg/hr, however, the solids capture was only65 percent. Addition of 1 Kg/t of a cationic surfactant provided filter cakes with 19.1 percent, 23percent, and 34 percent moisture using hyperbaric, vacuum, and centrifuge, respectively. Similarly, addition of 0.5 Kg/ton of copper chloride lowered filter cake moisture to 20.7 percent and 24.8percent, using hyperbaric and vacuum. With the centrifuge no improvement in filter cake moisture was noted. However, use of 80 Kg/ton of `orimulsion' in the centrifuge provided dewatered product containing 26 percent moisture, and the solids capture increased from 65 to 95 percent. The dewatered product appeared dry and was easily handleable.

Jan 1, 1999

By Johannes Moeljono, Werner Wenzel, Heinrich Wilhelm Gudenhau

As an important mechanism for increasing production of the suction-draft-sinter process, it has been shown that gas permeability through the sinter layer plays an important role. Methods to increase production rates have been indicated and suggestions for carrying out the process have been made to improve the rate of production, reduce the fuel consumption, and at the same time obtain a uniform sinter. Laboratory experiments were conducted at the Institute for Ferrous Metallurgy of the Technical University at Aachen to illustrate these methods. Methods of Increasing Gas Penetration Through Sinter Layers The following are of fundamental importance in determining the process cycle during the sintering of iron ores: 1) Generation of maximum temperature, since its form and range determine sinter quality. 2) Propagation velocity of the temperature maximum which controls the attainable output. 3) The convective heat transfer which influences the velocity of travel of the temperature maximum.

Jan 1, 1974

By Weslei Viana Gabriel

O fluxo simétrico e distribuição de temperatura uniforme são de grande importância no processo de Lingotamento Contínuo de Beam Blank, porém a utilização de duas válvulas para alimentação do molde traz dificuldades operacionais relacionadas ao posicionamento das válvulas e controle de vazão. Neste sentido é interessante trabalhar com apenas uma válvula. Neste trabalho técnicas de modelagem física e matemática foram utilizadas para avaliar o fluxo de fluido no molde, comparando-se o caso em que se empregam duas válvulas tubulares, com aquele em que se utiliza apenas uma válvula. Verificou-se que esta última configuração resultou em uma mudança no comportamento do fluxo, aumento na profundidade de impacto, porém a velocidade na região do menisco não teve variação significativa em comparação com a utilização de duas válvulas tubulares.

Aug 16, 2017

By R. V. Ramani

This volume is the fourth of a four-volume final report on research carried out under a contract from the U.S. Bureau of Mines on the development of a computer simulation model for surface mine reclamation planning. The other volumes are titled as follows: Volume I: Ore Reserve Estimation, Volume II: Dragline Model, and Volume III: Mine Coordinate Generator System. The Open Pit Materials Handling Simulator (OPMHS) was first developed" in 1971 and modified and updated in 1975. The present work is an update of the 1975 version and provides a direct link between the geology and reserves system and the various activities of the mining equipment in a mining system. Also, the modeling techniques in OPMHS/2 have incorporated a flexible method for describing various equipment (shovels, trucks, belts, trains, etc.), locations, their sequence of operations, place changes, and their interactions. These features allow for studying mining equipment selection, mining method analysis and reclamation planning. This report describes the Open Pit Materials Handling Simulator Version 2 (OPMHS/2). The report details the program features, operation, and application. Through an extensive set of appendices, the data input sequence, input variable definitions, sample data listing and program output are presented in detail.

Jan 1, 1985

This paper aims to collate the metallurgical test work undertaken on the Barrytown mineral sands deposit. It is intended to serve as a summary of mineral dressing work undertaken by all interested parties up to the time of writing. Areas requiring further investigation are: in situ grades and recoveries of accessory minerals,the question of 'rank' of ilmenite within the deposit,flow sheet development for the recovery of gold and monazite, andcost analysis to investigate the relative worth of other minerals; notably rutile. Flow sheet development with respect to the Accessory Minerals cannot be accurately defined until the importance of each mineral in terms of grade, recovery and expected revenue is determined. To date, ilmenite and zircon flows are well documented. Further work is needed to quantify recovery's and flows of the other minerals; notably monazite, gold and rutile.

Jan 1, 1989

By David Vergara Segura

Una empresa minera, en condiciones normales, maximiza su operación y minimiza sus pérdidas por tener operativos y equipos ligados a la producción. Por lo que es necesario la integración entre las áreas de la empresa, específicamente entre las de Mantenimiento y Logística. En este sentido, el presente texto señala la importancia del trabajo en equipo entre estas dos áreas, cuyo objetivo común es optimizar la gestión del activo que tiene un impacto significativo y directo en la producción. También se plantea bajo del esquema de una empresa minera ficticia, el desarrollo de estrategias conjuntas, y se define un modelo de gestión logístico, generador de ventaja competitiva, el cual está orientado a la optimización del uso del activo.

Sep 12, 2005

By B. P. Sereda

The properties, characteristics and phase structure of chamotte refractories produced with the usage of mullitecorund chamotte and caoline have been given. The comparison of new refractory C-45 obtained by us and refractory C-43 produced by traditional method has done. The physical-chemical properties of refractories is reviewed. The visual porosity, density and pore characteristics of given refractories was calculated. It is established that C-45 has the less gas permeability then C-45 that gives melting units more stability. The petrographical microstructures of refractories have been done. The main phase structures and their influence on refractories properties have been observed. It is established that refractories with mullitecorund chamotte adition has more advantages then refractories gained by traditional method and can be applied to melting units.

Jan 1, 2010

By Henry Louis

THE work performed by the Royal Commission on Mining Subsidence is likely to prove of permanent value, less perhaps for the conclusions it has reached and for the recommendations it has based upon these than for the admirable exposition which it affords of the law concerning mining subsidence and of the legal status of the person who has suffered damage by reason of such subsidence, as also of him whose working has caused the damage. The Commission was appointed by Royal Warrant in the middle of 1925 and delivered its final report in the middle of 1927. The terms of reference to the Commission were as follows: "To consider the operation of the law relating to the support of the surface of the land, and of buildings or works on or under the surface, by underlying or adjacent minerals; to enquire into the extent and gravity of the damage caused by subsidence owing to the extraction of minerals and the incidence of the resulting liability; and to report what steps should be taken, by legislation or otherwise, to remedy, equitably to all persons concerned, any defects or hardships that may be found to arise in existing conditions."

Jan 1, 1929

By S. Bellec, P. Champagne, J. Châteauneuf, A. Berton, S. Fortier

"The start-up of new plants, extending from the commissioning of equipment to the production ramp-up, is a critical period where the processing circuit operation must be done in a structured and well controlled way to enable the gradual, safe and rapid achievement of production targets. The magnitude of the many risks associated with this pivotal period is accentuated in the actual context of low commodity prices. However, the implementation of a method that analyzes risks associated with a start-up, their probability of occurrence and their impacts leads to the identification of a series of preventive actions that can be applied in order to reduce potential negative impacts.Soutex has been involved in numerous start-ups over the last few years and has developed a structured methodology to assess this crucial period, maximize the pre-start-up preparation, ensure a smoother and safer ramp-up period and minimize the time needed before reaching commercial production.This paper describes a method to identify preventive actions to apply in order to reduce risks related to a plant start-up. Then, the various steps of the method are demonstrated using the industrial case study of the Canadian Malartic gold plant situated in Abitibi, Québec. The specific preventive actions, during start-up, the organisational measures and the ramp-up plan are detailed as they were effectively achieved. Finally, the post start-up actions are presented as well as some key results illustrating the achievement of their prior defined objectives.IntroductionPlanning a new plant or new circuit start-up in a mine installation involves various risks, both at the economical and safety levels. Unprepared staff and equipment can lead to safety issues that could threaten plant staff as well as the environment. Moreover, a poorly prepared start-up could often lead to equipment break-down, production stoppages and delays, leading to important economic impacts, delaying commercial production and therefore affecting directly the profitability of mining projects.It is common in the industry to have structured commissioning procedures for major equipment taken separately. Technical personnel from the equipment manufacturing company would usually come on site in order to perform the pre-operation verification, dry runs and the first hours of operations. This kind of assistance is usually focussed on one piece of equipment and neglects the interactions between the various equipment of the production chain. The commissioning phase is usually maintenance oriented and the information given by the manufacturing representative seldomly flows through the operation staff (in the case of this paper, the denomination “staff” refers to both managing and operating employees). The global process is usually not taken into consideration by the technical personnel sent on-site by the manufacturer during the commissioning phase. Many papers can be found describing the commissioning of new equipment focussing on the technology (Côté and Adante (2009), Wells et al (2007)) but without dealing with its integration process in the complete production chain."

Jan 1, 2016

By K Cameron, S Strohmayr, J Wallace

In 2012, a single module heavy medium cyclone plant (HMP) was installed at the Glencore Zinc’s (then Xstrata Zinc) McArthur River lead zinc mine. The HMP formed the first part of the MRM Phase 3 Project to increase run of mine (ROM) capacity from 2.4 to 5.5 Mt/a.The purpose of the HMP is to remove liberated gangue from the crusher product at minimal loss of valuable mineral. The McArthur ores are very finely disseminated requiring a fine primary grind size prior to rougher flotation. Rejecting waste prior to grinding therefore offers significant power and grinding media savings. The plant was designed to treat only those ores with a reasonable upgrade ratio at the target zinc recovery across the HMP of 95%.On this basis, a 1.8 Mt/a single module plant was built based on 250 t/h feed rate and 82% availability. In contrast to existing base metal heavy medium plants in Australia, the MRM Flow sheet utilised the principles in modern coal heavy medium cyclone plant design. Since commissioning, the plant feed rate has been significantly increased and is now normally operated up to 540 t/h (dry basis).Although this throughput increase is partially due to debottlenecking work, it is also attributable to the conservative design parameters for base metal heavy medium cyclone circuits in comparison to those used in equivalent coal circuits.This paper discusses Flow sheet design and compares traditional base metal design parameters with those achieved at MRM and those of modern coal plants. It provides information on plant capital and operating costs and the net savings realised by its installation. In addition to power and grinding cost savings, the paper also highlights the savings in water through rejection of near dry waste and reduction of tailings pumped to the storage dam.CITATION:Wallace, J, Strohmayr, S and Cameron, K, 2015. McArthur River Mine heavy medium plant – the benefits of applying modern coal plant design principles to base metal heavy medium separation, in Proceedings MetPlant 2015, pp 311–323 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

By B Xiao, J Yang, H Chen

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Tuwu-Yandong Cu deposit, located in the East Tianshan mountains in the eastern section of the Central Asian Orogenic Belt, is the largest and economically most important porphyry Cu deposit in Xinjiang, China. It contains ~3 Mt of copper at an average grade of 0.46 per cent Cu and 0.2 g/t Au, with significant amounts of Mo and Ag. The deposit is mainly hosted in the Carboniferous Qi’eshan Group and plagiogranite porphyry, and is controlled by faults that are east–west-, north-west- and north-east-trending. Ore minerals in the Tuwu-Yandong deposit are dominated by pyrite, chalcopyrite and molybdenite, with minor bornite, chalcocite, magnetite, sphalerite and galena. Gangue minerals are mainly composed of quartz, sericite, chlorite, epidote, anhydrite, gypsum, muscovite, biotite, phosphorite, sphene, dolomite, actinolite, barite, albite and calcite. Based on the megascopic and microscopic textural relationships and mineral assemblages, five stages of hydrothermal alteration and hypogene mineralisation are recognized in the Tuwu-Yandong Cu deposit: the potassic stage, propylitic stage, phyllic stage, late veins stage and supergene stage. Most of the copper was deposited during the phyllic stage, along with less molybdenite.CITATION:Xiao, B, Chen, H, Wang, Y and Yang, J, 2015. Geology, mineralisation and alteration of the Tuwu-Yandong porphyry Cu deposit, north-west China, in Proceedings PACRIM 2015 Congress, pp 641–644 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015