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By Hsun Hu

Based on Kurdjumoiv-Sachs orientation relationship for the fee bee transformation in metals, the jirzal crystal orientation resulting from successive transformations of bee-fee-bee has been analyzed mathematically. There are 528 different variants; many of ther are crystallograpyically equirvalent. Specific examples show that, for equal probability of all the variants, the principal crystallographic axes [100 ], [110], and [111] of the initial bcc crystal can be transformed into vairous axes in the fina1 crystal However, fur each of these principal crystallographic axes, a continuous range of orientation within certain regions of the unit triangle is completely avoided by the finctl Crystals. For uses of higher indices, the final orientations are more uniformly distributed throughout the unit triangle. Results from the PI-esent analysis are in good agreement with preferred Oientations Observed in a zone-meltecl iron bar. THE allotropic forms of iron are characterized by the unusual fact that at both high and low temperatures a bcc structure is stable, whereas at intermediate temperatures (1400" to 910°C) the metal is fcc. Hence, during cooling from its melting temperature, iron undergoes successive phase transformations ofd—? —a with corresponding changes in the crystal structure of bcc — fcc -bcc. while numerous studies have been made in the past of the 1 — a transformation in iron and in various iron-base alloys, no information is available in the literature as to the mechanism of 6 — l transformation and the lattice orientation relationship between these two phases. Experimental difficulties have apparently prevented researchers from undertaking these studies. The laltice orientation relationship between the parent and the new phases of iron resulting from

Jan 1, 1965

By C. Dinis da Gama

In mining, all unit operations are closely interrelated, and the results of blasting are probably the key factor within that sequence. The drilling program prior to blasting is just as dependent upon the desired rock fragmentation as are the loading, hauling, and mechanical crushing operations which are economically and technically influenced by the results of blasting, namely, the size and scatter of the product. What is known today as optimum blasting is the process of designing a blast in order to obtain a certain degree of fragmentation so that overall mining costs are minimized. Applying this criterion often results in a different program than when an individual blasting pattern is chosen only on the basis of the lowest operational cost for that pattern, disregarding what comes before or after the blast. [Fig. 1] shows the characteristic variation of mining unit costs with the degree of fragmentation, or the maximum size of blocks obtained from blasting. From the figure, it can be seen that optimum breakage must correspond to the lowest total costs, but reducing drilling-blasting costs only does not achieve such an optimum solution. Methods of designing surface or underground blasting operations should comply with the optimization criterion, but this compliance is feasible only if a detailed mining system analysis is available. Therefore, predictions of costs of loading, transporting, and mechanical breakage of ore as a function of its size will define a narrow range of variation for drilling and blasting parameters in order to get the minimum total costs.

Jan 1, 1972

By Roy L. Zuber

Identification and analysis of mining hazards involves the correlation of accident, injury and illness information from all segments of the mining industry. It would not be feasible to process the volume of data involved without substantial reliance upon a computerized information system similar to that maintained by the Health and Safety Analysis Center. Numerous statistical programs are applied to the computerized accident-injury-illness data base to identify those mining tasks and associated activities which are responsible for most of the injuries and occupational illnesses. These programs are used to flag those mining tasks or conditions at specific mines or segments of the mining industry where either a significant increase in the injury/illness trend has been reported or where the number of injuries/illnesses related to specific mining tasks or conditions are high. Upon identification of those mining hazards which warrant further analysis, a computerized search of the coded accident data is performed to correlate the predominant categories by cause of injury or illness, source of injury, nature of injury, type of accident, etc. From this correlation, those factors most common to the conditions responsible for the hazard may be identified. Based upon analyses of this form, recommendations are made regarding the appropriate engineering, training, and/or operational improvements necessary to alleviate the hazard. In addition to mining hazard analysis, the computerized data base also has application in the area of optimum resource allocation. Computer programs have been developed to assist management in allocating resources based upon organizational requirements and historical accident - injury trends.

Jan 1, 1983

By F. L. Wilke

A model is presented to minimize the winning costs per shift within the different sections of a potassium mine by liner programming and to simulate the other areas to get all costs in order to comp re different production strategies. he model is based on a a given total layout of the underground mining which is considered to be fix during the planning period. Room-and-pillar mining is assumed to be used. Potassium extraction is done by drilling and blasting. Transportation of the raw material to sectional crushers is done by scoop-trams where it is crushed to coarse-grains which allow further transportation by conveyor belts to the hoisting shaft or to a bunker. When production is stopped, the continuously working factory is supplied by means of this bunker. Starting from a desired composition of the raw material the model has to keep the given total. demand of raw material per shift, to minimize the winning costs, to keep the capacity constraints of the equipment and to determine the planned output of production of the sections per shift. Costs of the areas which follow the extractions are added to extraction costs in order to allow a comparision of costs of several alternatives of production. Optimization in extraction and assignment of scoop-trams to sections is done by linear programming. The other areas of the mine are treated by simulation. The model output is a schedule of the calculated costs broken down into costs of processes, equipment, and kinds of costs. This proceeding enables to compare different ways of production.

Jan 1, 1979

By A Thompson, E Villaescusa

The Western Australian School of Mines (WASM), Kalgoorlie, has been performing dynamic testing of reinforcement systems as part of the Minerals and Energy Research Institute of Western Australia (MERIWA) Projects M349 and M349A sponsored by WASM, the Western Australian State Government and the mining industry. These projects have resulted in the construction and commissioning of the WASM Dynamic Test Facility and a program of reinforcement system testing. The primary purpose of the WASM projects is to evaluate the performance of complete reinforcement systems when subjected to an axial dynamic load. The test procedure, monitoring and associated analysis enable assessments for each component (ie the element, the internal fixing mechanism and the surface hardware) of the reinforcement system. The performance of a reinforcement system is usually defined by a static force-displacement response to axial loading. However, this static response may not be applicable to dynamic loadings associated with violent failure of rock due to overstressing as mines progress to greater depths. It was therefore appropriate that the responses of reinforcement systems subjected to dynamic loading be defined and evaluated. The key findings from the tests on a number of reinforcement systems are presented and recommendations made regarding their application for dynamic loading.

Jan 1, 2008

By I. S. Escobar

Copper, particularly the oxygen-free grade Cu-OFP, is a candidate material for containers for the long-term isolation and disposal of high-level radioactive waste (HLW) in underground repositories. After having been buried for a few hundred years, all oxygen will have been consumed in the repository, and corrosion of the copper will be caused entirely by contact with dissolved sulfides. Chloride is another potential corrodant, but in deep repositories where groundwater is neutral or slightly alkaline, the effect of chlorides can be ignored on thermodynamic grounds. Thus, the corrosion of copper in the presence of sulfide ion and under reducing conditions has been studied using cyclic voltammetry and Tafel slope measurements. It is possible to determine the effect of sulphide ion on copper corrosion resistance which is minimized at low temperature and also at low sulphide concentration. The presence of anions such as HCO3 under environmental conditions produces a beneficial effect because these ions are inhibitors.

Jan 1, 1999

By W. Kauenhowen

The production of petroleum in Germany during 1932 totaled about 1,608,558 bbl., a slight increase over the 1, 602,517 bbl. produced in 1931. A decline, as shown in Table 1, occurred chiefly in the Volkenroda (Thuringia) field. The total production of the other fields (salt domes), however. reached a new record, about 21 per cent above 1931. Table 1.—Oil Production of Germany by Fields and Oil Provinces, 1928-1932 (Barrels of 42 Gallons)" Salt Dome Province __________________________________________________|_________________________________________________________________________________________________________________________ 1928 274,323 322,742 679 46,319 644,021 644,315 1929 310,891 337,582 10,535 67,578 719,901 720,069 1930 586,404 427,539 100,716 72,485 1,186,969 29,806 1,220,296 1931 506,548 403,634 213,549 116,088 1,242,598 360,885 1,602,517 1932 769,405 366,982 230 979 130,711 1,498,077 110,481 1,608,558 " Official figures published in Germany are given in metric tons. For the above conversion into barrels a factor of 1 metric ton equaling 7 barrels has been used. Includes a very small production from Hcide, Holstein. c Includes a very small production from Tegernsee, Bavaria, and Bruchsal, Baden. Nienhagen-Hanigsen Field In 1932 the Nienhagen-Hanigsen yielded about 51 per cent of the production from the four German salt dome fields. During 1932 the productive area was again extended, chiefly towards the northwest in the so-called north district, to which the present drilling activity is confined almost entirely. Since the discovery of the north district in 1928, about 45 wells have been drilled in it, of which only two were

Jan 1, 1933

By Manolete Mena

WC-Co nanocomposite powder is among the first group of materials with a promising potential for nanocrystalline-materials application. A chemical vapor synthesis (CVS) process that has previously been used for preparing the aluminides of titanium and nickel, and other metallic and intermetallic powders has been applied to the preparation of WC-Co nanocomposite powder. This CVS system was designed so that a tungsten precursor (WCl6 powder) and a cobalt precursor (CoCl2 powder) were separately fed into each evaporator in a reactor by means of specially designed powder feeders. The reduction and carburization of the vaporized chlorides by methane-hydrogen mixtures produced nanosized WC and Co composite powder. The product is a very uniform mixture of the constituent powders, which is important to ensure a high quality of the bulk cemented tungsten carbide product after consolidation. In the present work, the effects of reaction temperature, CH4 to WCl6 ratio, CH4 to H2 ratio, residence time, and Co content on the powder composition and particle size were determined. The products were characterized using XRD, carbon analyzer, and TEM.

Jan 1, 2006

By V. Bojarevics, K. Pericleous

"A number of different methods have been developed for noncontact electromagnetic treatment of liquid metal and to investigate the melting/solidification processes. Applying AC magnetic field in terrestrial conditions, along with the buoyancy and thermo-capillary forces, results in turbulent flow. The use of a homogenous DC magnetic field allows damping both of the turbulence and the large scale flow at different rates leading to surprising results at some stages. The dynamic interaction of the turbulent flow with the oscillating interface needs to be accounted if it is required to levitate liquid metal of up to few kilograms without the contact to container walls. At the high values of magnetic field some oscillation modes are damped quickly, while others are modified with a considerable shift of the oscillating droplet frequencies and the damping constants from the non-magnetic case. Numerical models are used to investigate behavior of liquid metal suspended in high DC magnetic fields providing microgravity-like conditions with laminar viscosity and heat transfer to the surroundings.IntroductionSince the early Electro Magnetic (EM) levitation experiments [1] in AC magnetic field it became apparent that the levitated liquid metal is prone to oscillation and instability. The EM and electrostatic levitation experiments with liquid metal droplets show difficulties related to confinement stability and a need for complex correction functions to establish a correlation between the measurements and the droplet material properties [2,3]. Intense internal fluid flow is visually observed, apparently being in the turbulent regime for earthbound conditions."

Jan 1, 2012

By Donald L. Everhart

SOONER or later intelligent exploration for uranium leads to these questions: Where did the metallic ions that formed the orebodies come from? What processes and geologic factors were involved in ore replacement? These matters, of course, make a big difference in how best to look for orebodies. Before these questions are discussed it might be well to point out other factors bearing on the subject. The whole business of uranium exploration is only a little over ten years old, participation by the public is only about six years old, and real interest and activity by more than a few large mining companies has arisen only in the past two or three years. Throughout this short period, uranium exploration has been affected by the unique influences of necessary security measures and by division of the over- all job into individual projects by a large number of specialists in diverse fields. This has meant that a normal interchange of information on the nature of uranium deposits has really only just begun. Com- pared to the vast amount of published studies on iron, copper, lead, zinc, and gold deposits over the past 50 to 75 years, current knowledge of uranium deposits is in its infancy and much of the pertinent information is still scattered about in a number of unpublished sources. The volume of reports on all phases of uranium exploration is now beginning to mount at a remarkable rate, and geologists with widely varying specialized backgrounds in uranium geology are engaging in spirited debates over the origin of uranium and the relative importance of geologic controls of various deposits.

Jan 9, 1954

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 William E. Hubbard

During the last decade the known reserves of petroleum in the United States have increased from about five billion to over thirteen billion barrels. From the standpoint of public welfare the existence of these known reserves presents an undeniably favorable picture, but viewed from the position of many a harassed operator the blessing has not always been considered an unmixed one. Along with this increase in excess reserves, curtailment of production has come into being as a matter of necessity and the principle of proration as a matter of equity. As a practical matter it has been considered necessary to curtail the production of old wells as well as that of new wells in a pool. The right of new pools to produce has been recognized, and the allowable for them has come partly from increased market demand and largely from the allowables already enjoyed by the developed pools. The natural result—a downward trend in daily per-well allowables—has been especially felt by Texas operators. This trend may be illustrated by Table 1, which comprises the five active areas in Texas, and from which may be noted the following: 1. The average daily allowable per well has decreased about 53 per cent in three years. 2. Of the 184,000-bbl. increase in total allowable for the five areas, 29,000 bbl. came from the increase in state demand and 165,000 from the combined allowables of the remaining pools in the state.

Jan 1, 1937

By H. A. Kursell

IN pre-war days, the mining industry of Russia occupied in the industrial life of the Empire a place of ever increasing importance. The peak of produc-tion was reached in 1913 and 1914, the years of greatest prosperity, and a rapid growth of the mineral industry seemed assured, especially as regards base-metal mining. Exceptions were the gold production, for which a gradual decline was anticipated, and the platinum out-put which was expected to remain steady. A greater productivity of labor, corresponding to better working facilities was noticeable, and the economic status of the working classes was constantly improving. The tremendous strain on Russia's economic life caused by the World War did not materially alter the prospects of the mineral industry and the fundamental changes began only with the revolution in the spring of 1917. Their scope and character are illustrated by the figures in Table 1 which compare, for the parts of the Russian Empire under Soviet (R. S. F. S. R.) control, the average mineral production of 1913 and 1914 with that of 1920, 1921 and 1922, as supplied by bolshevik sources.1The latter three years in Russia's history were characterized by the firm establishment in power of the Communist party as a new ruling caste. Silver, lead, zinc, tin, nickel, tungsten, barite, etc., were either produced in negligible quantities, or not at all. However, before the revolution the development of several argentiferous lead-zinc deposits in western Siberia had reached a stage which seemed to assure an appreciable output of the white metals for the near future.

Jan 7, 1923

By hydrometamorphism is meant the alteration of rocks, ores and minerals by atmospheric waters. In its broadest sense, it includes the varied processes of weathering, oxidation, hydration, the leaching of rocks and ores, and the solution, migration and enrichment of metals. Rain water, as it strikes the earth, is practically pure water, except for small quantities of dissolved atmospheric gases; upon coming in contact with ore minerals, especially sulphides, however, it is transformed into solutions of great chemical activity, which attack, transform and rearrange the minerals of ore- bodies, and so effect enrichments of the greatest economic importance. Primary deposits so low in grade as to be without commercial value are frequently thus transformed into deposits of commercial importance. It is necessary in the examination of any orebody, therefore, to determine whether the valuable ore is of primary or of secondary origin; if primary, its value may be expected to continue indefinitely in depth to the zone of primary impoverishment; if secondary, the ore deposition is known to be controlled by surface agencies, and the valuable ore may be expected to continue to such depths only as have been reached by surface waters. The decomposition and weathering of rocks, unlike the changes undergone by orebodies, are accomplished by water carrying as dissolved constituents chiefly atmospheric oxygen and carbon dioxide, together with vegetable acids. The chemical changes wrought are principally hydration, oxidation and the formation of carbonates. The tendency is toward the solution of the more easily dissolved minerals, which is attended by the formation and a surface concentration of the more resistant minerals,

Jan 1, 1932

By Sorokin M. L, Komkov A. A

Flash smelting of nickel sulphide concentrate has been practiced at WMC's Kalgoorlie Nickel Smelter for 20 years. The mineralogy of the concentrate from the original mines was particularly suited to this process. However, taking a strategic view, potential new processing routes should be fully evaluated as possible replacements for the current technology. The Vanyukov process has been under development in Russia for the past 40 years and has been successfully applied on a large scale to the smelting of copper concentrates, at two locations - Norilsk and Balkhash. The potential for the application of the Vanyukov process to the smelting of nickel concentrates offers a number of processing advantages, including smaller reactor and decreased dependence on fuel oil. This paper reports on preliminary investigations into the application of the Vanyukov process to the smelting of nickel concentrates. At this stage the investigations are limited to semi-quantitative comparisons and modelling studies.

Jan 1, 1992

By Huayang Luo, Hui Li, Wei Zhou, Gang Chen, Scott Huang

The beach and offshore gold resources demonstrated at Nome, Alaska are some of the richest found in Alaska. They contain potentially significant resources that may be exploited in the future. Several companies have contributed to the exploration and reserve estimation in Nome offshore gold deposits. More than 3,000 holes were drilled and over 10,000 offshore samples were analyzed in the Nome offshore areas of approximately 40 km2. Those 3,000 plus drill hole logs were converted into digital formats comparable with ArcGIS software. Considerable amounts of mineral resources data were processed and visualized using ArcGIS 8.3 and its geostatistic, 3D analysis, and spatial analysis components. In this study, based on the data processing and visualization results of ArcGIS, a user-friendly website for mineral resource management and utilization is developed using ArcIMS 4.0.1. ArcIMS is a GIS solution to build and deliver maps, data, and tools over the Internet. The Nome offshore mineral resources website presents the geostatistic and GIS analysis information. This site allows clients to access the information and perform ArcGIS analysis, such as interactive data query, and map layers display of the gold resource distribution, average grade, gold reserve, and relative mineral resource estimation via remote computers. With linkage to other related mining web sites, this web site allows users to search for related publications and more flexibly manage the information. A few other appropriate customized tools are also being developed to assist interactions between the server and clients for data analysis and management.

Jan 1, 2005

By Robert B. Parsons

"Finance Minister Paul Martin's first budget disappointed almost everyone. The business sector was disappointed at the some what feeble attempt to grapple with the country's deficit. The mining industry was disappointed by tax proposals regarding mine reclamation that fall short of the industry's needs. Has anybody been happy with a federal budget? Federal Budget DisappointsThe federal government's budget papers that were tabled on February 22, 1994, contained a rather bizarre mixture of unrelated tax proposals. The budget signals an unexpected attack on the tax treatment of debt settlements, on certain types of corporate reorgani2ations, and on income earned by foreign affiliates. This is an old style budget, which proposes a pot pourri of technical changes and policy initiatives. Mine ReclamationEffective February 23, 1994, a taxpayer's contributions to a prescribed mine reclamation trust fund will be deductible as a current expense. The budget papers do not provide a definition of what will constitute a ""prescribed"" trust: this definition will surface in due course. However, the budget papers indicate that:• income earned in such trusts will be subject to tax each year;• all withdrawals from the trust (including income already taxed) will be included in computing the income for tax purposes of the recipient;• reclamation costs will continue to be fully deductible at the time incurred; and • contributions, trust earnings, and withdrawals will not be taken into account for the purposes of determining a taxpayer's resource allowance."

Jan 1, 1994

By J. J. De Witte, J. G. Cazort

The Paranam plant in Surinam (formerly Dutch Guiana) was built during 1939-40 to supply crushed and dried bauxite for the growing U.S. aluminum industry, supplementing production from the Suriname Aluminum Co.'s Moengo works, which began operation in 1922. A subsidiary of Aluminum Company of America, Suralco's total annual production from these two plants averages 2.55 million dry metric tons of various grades of bauxite. Starting in 1941 with bauxite from mines on the west side of the Suriname River, annual production at the Paranam plant has varied from a low of approximately 450,000 tons to more than 1 million tons in 1949. High production rates during World War II and the late 1940's rapidly depleted these reserves, and in 1950 plans were made to mine the known deposits on the east bank of the river, about five miles downstream from the original Paranam plant.

Jan 11, 1960

By Henry Kreisinger

IN evaluating coals as steaming fuel on the basis of chemical and physical properties of the coals, the only properties that can be used are those for which the methods of determination are well established and standardized, and those that affect all methods of burning the coals in the same way. The discussion is written from the standpoint of the coal consumer. The production of steam is the largest field for the use of coal. It includes stations for generating electric power, central heating plants, industrial power plants where steam is used for power generation, factory processes and heating. The field also includes steam locomotives. Small house-heating boilers are not included in this field because such small boilers generally burn specially prepared domestic fuel. The plants using the steam coal are equipped to burn the coal when fired by one of the three general methods: namely, hand, stoker, and pulverized coal. The hand firing is now restricted to small plants and to locomotives. Central stations and larger industrial plants use either stoker or pulverized-coal firing. Some locomotives also use stokers. Pulverized-coal firing has been tried in locomotives but so far its adapta-tion to this use has been handicapped by practical difficulties. The coals used for steaming purposes are generally of the bituminous and semibituminous classes, with volatile matter ranging from 15 to 35 per cent. Coals belonging to these classes are produced in many parts of the United States and form by far the largest part of the total coal production of the country. The value of any coal as fuel for steaming purposes depends on the following factors

Jan 1, 1935

By J. E. Gebhardt, P. E. Richardson

External control of the electrochemical potential of a bed of mineral particles was investigated by the US Bureau of Mines as a method for controlling particle interaction with organic collectors and, thus, flotation response. A cylindrically shaped, 200- to 300-g bed of sulfide mineral particles was used as the working electrode in an electrochemical-flotation cell. In a pH 9.2 sodium tetraborate buffer, chalcocite floated with ethylxanthate at applied potentials [=] - 0.25 V (versus the standard hydrogen electrode) ; pyrite floated at potentials [=] 0.15 V. Differential separation of a chalcocite-pyrite mineral mixture was obtained by controlling the potential, but the flotation response of the mixture did not follow the behavior predicted from measurements on the individual mineral beds. Chalcocite dissolution products had a deleterious effect on chalcocite-pyrite separation by activating pyrite so that it floated below the potential (~ 0.13 V) at which xanthate is oxidized to dixanthogen. A pyrite bed activated with a copper(II) sulfate solution exhibited a flotation response with a potential dependence between that of chalcocite and pyrite. Pyrite dissolution products had no effect on chalcocite flotation.

Jan 1, 1988