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By Chris Plackowski, Bruckard. Warren J., Anh V. Nguyen

"Enargite is a significant penalty mineral in the copper industry and its separation from many copper sulfides by flotation is difficult. The separation may be crudely achieved using selective oxidation techniques or through the use of pulp potential control. This paper summarizes our latest contributions to a better understanding of enargite surface electrochemistry and hydrophobicity. Oxidation, roughness, hydrophobicity and species formation on the surface of natural enargite were examined by a novel experimental approach that combines electrochemical techniques, atomic force microscopy, X-ray photoelectron spectroscopy and droplet evaporation tensiometry. It allows for synchronized electrochemical control and examination of the oxidative surface morphology, speciation and hydrophobicity of enargite at pH 4 and pH 10. At low pH, surface layer formations consisting of metal deficient sulfide and elemental sulfur were identified associated with a limited increase in roughness and heterogeneous distribution of surface species produced by initial rapid dissolution of Cu, followed by diffusion limited surface layer deposition. At high pH, a similar diffusive mechanism associated with oxidation products consisting of copper sulfate and hydroxide and a significant increase in surface roughness were established. Receding contact angle measurements showed no significant difference in the contact angle on a surface oxidized at pH 10 and the freshly polished surface. Contact angle increased from 46° on the polished surface to 59° after oxidation at pH 4. Competing effects of hydrophilic copper oxides and hydroxides, and hydrophobic species of elemental sulfur on the mineral surfaces under oxidizing conditions at pH 4, and the change in surface roughness at pH 10, contribute to the changes in enargite hydrophobicity under electrochemically-controlled oxidation conditions. Most likely, both surface species and surface roughness produced by oxidation are critical to the changes in the wettability of enargite and other sulfide minerals."

Jan 1, 2014

By V. S. Znamensky, R. V. Stewart

This chrysotile asbestos ore body is located near the northern tip of the Province of Quebec, Canada. It is some 1818 km (1130 miles) north of Montreal, 480 km (300 miles) north of the tree line, and is situated within the zone of continuous permafrost. The open pit ore zone is approximately 0.4 km (1% mile) in length, some 61 m (2OO ft) in width and plunges at 25o to 30 o below surface to a vertical depth of at least 610 m (2000 ft). The ore body was originally evaluated by programs of surface mapping, diamond drilling, and bulk sampling. The fiber is semicrude, possesses excellent strength, and good fiber length distribution. GEOLOGICAL SETTING, LOCATION, AND DISCOVERY The chrysotile asbestos mineralization at the Asbestos Hill mine occurs in serpentinized ultrabasic rocks of Precambrian age. These intrusive rocks are found in older volcanic sedimentary rocks known as the Cape Smith-Wakeham Bay belt and are shown in Fig. 1. The rocks comprising this belt overlie older basement rocks composed of granite and granite gneiss. This belt has a width of 32 to 64 km (20 to 40 miles), and trends in a general east- west direction, a distance of about 370 km (230 miles) from Wakeham Bay on the east coast of the Ungava Peninsula to Cape Smith, located on the east side of Hudson Bay. Two sequences of rock have been recognized in this belt. The lower (oldest) rocks are known as the Povungnituk group, and consist principally of massive lavas and sediments. The upper (younger) rocks are known as the Chukotat group, and are composed of pillowed lavas with interbedded sedimentary rocks. Sills of ultrabasic rocks exist in both younger and older rocks, but are more often found in the Povungnituk group. Concentrations of chrysotile asbestos, as well as nickel and copper minerals are found at or near the base of ultrabasic sills, and are most common where a change in dip occurs. The mine is situated about 1818 km (1130 miles) north of Montreal, approximately 1126 km (700 miles) north of the start of continuous permafrost, and about 482 km (300 miles) north of the tree line. The depth of permafrost at the mine site has been calculated to be approximately 549 m (1800 ft). This rich deposit of asbestos was discovered in 1957 during extensive exploration for nickel in the Ungava nickel belt. During that year, traverses conducted by Murray Watts spotted interesting looking ultrabasic rocks, and followup ground examination disclosed rich surface showings of asbestos mineralization near the present open pit. In 1958, a two-man prospecting party returned to the discovery site and a mineral exploration license was granted to Fig. 1. Location map Keewa Quebec Mines Ltd., a wholly owned

Jan 1, 1986

By Dmitri Goljandin, Jaan Kers, Xiangjun Zuo, Lifeng Zhang, Priidu Peetsalu

"In this paper, the mechanical milling of the electronic wastes was carried out. The metal parts and plastic parts were roughly separated. The final plastic powder size could be as small as ~100 µm. Then the pyrometallurgical recycling Printed Circuit Boards (PCB) was executed. The mechanisms of thermal degradation and combustion are investigated using TG/DTA and MS. Some chemical powders, such as Na2CO3, NaHCO3, NaOH and CaCO3 are used to control the exhausted toxic gas such as Br2. Introduction Waste electric and electronic equipment (WEEE), or electronic wastes (E-wastes), has been taken into consideration not only by the government but also by the public due to their hazardous material components [1-3]. From the point of material composition, electronic wastes can be defined as a mixture of various metals, particularly copper, aluminum, and steel, attached to, covered with, or mixed with various types of plastics and ceramics [4]. Precious metals have a wide application in the manufacture of electronic appliances, serving as contact materials due to their high chemical stability and their good conducting properties. Platinum group metals are used among other things in switching contacts (relays, switches) or as sensors to ascertain the electrical measurand as a function of the temperature [5]. Table 1 [6] gives examples of the metal composition of different electronic scraps from literatures. Additionally, non-ferrous metals and precious metals content have gradually decreased in concentration in scraps. The value distributions for different electronic scrap samples are shown in Table 2 [6], where the metal price data are from London Metal Exchange (LME) (Octoebr 2007). It can be seen that for cell phones, calculators, and printed circuit board scraps, the precious metals make up more than 70% of the value, for TV boards and the DVD player they still contribute to about 40%. This indicates that the major economic driver for recycling of electronic waste in industry is from the recovery of precious metals. Behind the precious metals come copper and zinc, while Al, Pb, and Fe are less value. Recycling of electronic waste is an important subject not only from the point of waste treatment but also from the recovery aspect of valuable materials."

Jan 1, 2008

By K Orth

The volcanic successions that host massive sulphide deposits are diverse in composition, facies types and facies relationships. They also show a variety of spatial and temporal relationships to mineralisation. In many examples, such as the Koongie Park Formation in Western Australia, the host succession includes more or less conformable syn-volcanic sills with peperitic contacts. Such sills can be an important source of heat for fluid circulation, influencing patterns of hydrothermal alteration and the location of co-eval and later mineralisation. The impact of syn-volcanic sills on the host succession depends in part on the initial porosity and permeability of the enclosing facies. The special properties of glassy pumice û being highly porous, permeable, and reactive û allow pumice-rich facies to preferentially focus hydrothermal fluid flow. However, the same properties promote early alteration and porosity reduction. Hence, the diagenetic and compaction history of pumiceous facies strongly influences their potential to host massive sulphide mineralisation. In contrast to pumice, dense glass has relatively low porosity, at least initially, and does not compact. Non-vesicular glass is a major component of submarine lavas, syn-volcanic intrusions and some volcaniclastic facies. However, especially in submarine settings, dense glass is commonly intensely perlitically fractured soon after eruption. The fractures greatly increase the porosity and permeability, locally accelerating diagenetic and hydrothermal alteration. In addition to false pyroclastic textures, altered perlite may exhibit false porphyritic textures. Silica- or feldspar-altered perlite kernels surrounded by intensely altered phyllosilicate domains can resemble phenocrysts in a fine grained groundmass.

Jan 1, 1999

By C. S. Simons

This paper presents a review of the extractive processes used in the production of nickel, with emphasis on developments since the beginning of the Second World War. Attention is given to the factors, many outside the nickel industry itself, which determined the direction of process research and strongly influenced the ultimate commitments to industrialize the resulting developments. An example of such a factor is the sudden surge in demand, far exceeding the then available nickel production capacity, that was caused by the advent of World War II; the result was the first serious consideration ever given to low- grade laterites as a viable source of primary nickel. Other factors discussed include such items as process development in the extraction of other metals - particularly copper; the availability of increasingly sophisticated materials of const- ruction; the advent of the "environmentalist" and related political developments; the massive escalation in the price of energy - particularly oil. The paper concludes with an attempt to forecast the nature of the most effective nickel process of the future, based on extrapolation from the economic and political situation that exists today.

Jan 1, 1988

By Kostas Fytas

A computer package has been developed which is capable of evaluating alternative production schedules (long and short range) of an open pit mine once the ultimate pit limits have been defined. The model user can choose the best alternative according to cash flow considerations and the particular mining conditions. The package involves a combination of simulation for long range production scheduling and linear programming for short range scheduling. The simulation model based on an iterative technique, maximizes the profits within each long scheduling period (eg. year or sixth month period), and at the same time defers stripping as long as possible. A minimum exposed ore quantity is kept at the beginning of each mining period. The final long range schedule satisfies a set of constraints for each period, mainly ore quality and quantity constraints for ore and waste. An interactive smoothing procedure at the end of each period results in a schedule that is feasible in terms of mining practice. Finally a cash flow analysis model carries out cash flow calculations so that the user can select the best alternative. The linear programming model, based on a certain number of shovel regions, defined interactively by the model user, calculates the optimum production schedule for each short period under consideration, so that a set of constraints is satisfied.

Jan 1, 1986

By W. Holding

Since the 1975 International Mine Ventilation Congress in Johannesburg there has been a trend in South Africa towards making the mine ventilation departments responsible for monitoring the total environment. This includes the taking of noise and illumination measurements and there is in fact a debate taking place as to whether the departmental title should be changed to 'Environmental Control Department'. The organisers of the 2nd international Mine Ventilation Congress have decided that noise and illumination will not be included as Congress subjects and 'Total Environment' includes only those facets which are open to debate at the Congress. The choice of mine is significant in that while most Congress papers from South Africa will be devoted either to coal mining or to the somewhat unique deep level gold mines, Prieska Copper Mine is a mine which can easily be identified with similar mines in many other parts of the world. The mine is situated some 750 km south west of Johannesburg and about 600 km north east of Cape Town. Current production (ore and waste) is about 340 000 tons per month and the total underground labour force is just over 2 000. The ore body is a massive sulphide, the main minerals being copper and zinc and the method of mining is sub-level open stoping. Daily average surface temperature conditions range from 85°F (29.5°C) dry bulb and 69.8°F (21°C) wet bulb in mid-summer to 42°F (5.5°C) dry bulb and 36.5°F (2.5°C) wet bulb in mid winter. The information presented in-this paper is limited to what can be gathered by mine ventilation staff as part of an on-going exercise and is obviously not as comprehensive as would be the case if a fully equipped research establishment were to become involved. The paper will be divided into three sections 1) Gases 2) Dust 3) Heat In each section statutory and/or other standards will be set down followed by a discussion of assessment and in some cases control methods.

Jan 1, 1980

By John Henry Harden

THIS shaft, located in the northern anthracite coal-field about 2300 feet southwest from the court-house at Wilkes-Barre, in the County of Luzerne, Pa., is the property of the Lehigh & Wilkes¬Barre Coal Company. The sinking and cribbing to the solid rock (see isometrical view on Plate IX) was conducted by Mr. W. W. Kenrick. Dimensions of the earthwork to the foundation of the cribbing, 51' 1/2" long, 17' 4" wide, 31' deep. Total amount of excavation in cubic yards, 998.5. Dimensions within the permanent cribbing, 45' 4" long, 11' 16" wide, 31' deep, divided into six parts by buttons 8" x 12", each division, 7' x 11’ 16". Permanent cribbing 12" x 12"; temporary cribbing 8" x 10"; backing, 3" thick ; clay puddle to ex¬clude surface water, 12" thick; conductors, 8" x 5"; lining, 1" thick from top to bottom of the shaft. In the latter part of the year 1871, Mr. H. Murray & Son contracted with the company for the continuation of the work at the rate of four hundred dollars per yard in depth, to a point 100 feet below the Hillman seam of coal ; for the succeeding 100 feet the price to be increased twenty-five dollars per yard, and so on until the bottom rock of the Baltimore seam of coal was found. The size of the shaft within the cribbing timbers is 45 feet 4 inches by 11 feet 6 inches, having six divisions of equal dimensions, 7 feet by 11 feet 6 inches, giving room for what is known as the" standard diamond" car, whose capacity when level full is 100 cubic feet, but when loaded by the miner 4 inches above the top contains 112 cubic feet.* Two divisions of this shaft are intended for hoisting coal from the Hillman seam, two from the Baltimore seam, one for ventilation, and one for pumps. The works were planned for two pairs of direct-acting, high-pres¬sure engines, twenty-four boilers, and for an estimated output of 2500 tons of coal per day from the two seams. * Size of the "standard diamond" car, 8' 10” x 4' 3" x 2’ 8” = 100.1.4; loaded 4 inches above the top, 8' 10” x 4’ 3” x 3’ “0"= 112.7.6.

Jan 1, 1877

As fulfillment of the requirements of Contract H0387019 for the United States Department of the Interior, Bureau of Mines, a complete field kit, for performing on-site determinations of individual employee Time Weighted Average (TWA) exposures to nitrogen dioxide (NO2) and nitric oxide (NO), has been developed by MDA Scientific, Inc. This report provides background information and experimental data validating the use of this kit with confidence to ? 10 percent accuracy.

Jan 1, 1981

By J. Parke Channing

IT IS most appropriate for mining engineers and in fact for all engineers to perfect themselves in leader-ship, because in the last ten years there has been a growing realization on the part of capital that there is no man who by capacity and training is better fitted to manage industrial production than the engineer. In high places the engineer and particularly the mining engineer is coming into his own. We have Mr. Hoover as Secretary of Commerce, Mr. Hammond as the head of the Federal Fact-finding Coal Commission, and Prince Caetani as Royal Italian Ambassador, all mining engineers. More and more in all industries is the manager more likely to be an engineer than he was five, ten, fifteen or twenty years ago, and the feeling is that the man who has had a technical training, whether from going to a school or from burning the midnight oil, makes a better manager than the man who has not. We find in mining that the best man for a manager is one who has had engineering, training. The manager who comes up from the office, from the purchasing department or from the transportation department may make a fairly good manager but he is never so good as the man who has had a technical training. He cannot speak the language of his staff.

Jan 5, 1923

By M. Zanini, D. Wong

ABSTRACT: Metals market improvements in 2005 drove the desire to increase nickel throughput and the production of nickel oxide sinter at the Vale Ltd. Copper Cliff smelter. Significant difficulties were encountered due to the unreliable quality of Bessemer matte being produced. Concentrate feed changes and the loss of technical and operational expertise during the previous market downturn contributed to the challenge of making the required improvements. Significant progress has been made in the converter aisle by focusing on employee engagement and standardizing best operating practices for a new generation of skimmers. This paper documents these initiatives and seeks to balance the art and science of converting.

Jan 1, 2012

By C. D. King

The key to maximum production of ingots for the war effort is maximum production of pig iron. For any given furnace and ore, the most important single influence on blast-furnace production is the quality of the furnace coke. It is generally recognized that undoubtedly deterioration of Pittsburgh coking coals will be accelerated by the depletion of some of the better grades of coal; the extension of mine mechanization, with attendant degradation of coal quality; and the opening of new coal fields, some of which are known to be fairly high in sulphur. All of these factors, contributing as they do to higher ash and sulphur, and not infrequently to inferior quality of coke, made it desirable that an extensive study be undertaken to determine the effect of washing some coals that closely approximate the average chemical composition of coking coals to be expected in the future by the subsidiaries of the United States Steel Corporation in the Pittsburgh district. It was deemed advisable to study the improvement obtained by washing such coals and to determine the need for supplementing the existing coal washery at Clairton to assure continued maximum production of pig iron from presently available furnace stacks. The existence of the coal washer at Clairton made it possible to conduct tests on coals used in raw form and on similar coals after washing. This study covers an investigation of the quality of furnace coke as affected by washing coking coals, and is confined to the use of 100 per cent high-volatile Pittsburgh seam coals from Fayette and Greene Counties in the manufacture of furnace coke. It covers the improvement in chemical and physical properties as well as the degree of uniformity in coke obtained by washing these coals, and includes the effect on blast-furnace production and practice. The test period involved is four months; the plants, Clairton by-product coke plant, and the Carrie No. 1 and No. 2 blast furnaces at Rankin, Pa., Carnegie-Illinois Steel Corporation. Clairton By-product Coke Plant and Coal Washer The Clairton by-product coke plant carbonizes 30,800 net tons of coal daily in 22 batteries containing 1482 ovens. Three oven sizes are used, commonly known as wide, medium, and narrow types, recognizing the difference in oven width, These ovens also differ in height and length. The present coal washer has a daily capacity of approximately 14,000 tons, leaving 16,800 tans to be carbonized in raw form. Washed coal is used on all the narrow ovens and on three of the six batteries with ovens of medium width, raw coals being used on all the remaining ovens. The customary arrangement is

Jan 1, 1944

By A. S. Odeh

ABSTRACT A simplified model was employed to develop mathematically equations that describe the unsteady-state behavior of naturally fractured reservoirs. The analysis resulted in an equation of flow of radial symmetry whose solution, for the infinite case, is identical in form and function to that describing the unsteady-state behavior of homogeneous reservoirs. Accepting the assumed model, for all practical purposes one cannot distinguish between fractured and homogeneous reservoirs fram pressure build-up and/or drawdown plots. INTRODUCTION The bulk of reservoir engineering research and techniques has been directed toward homogeneous reservoirs, whose physical characteristics, such as porosity and permeability, are considered, on the average, to be constant. However, many prolific reservoirs, especially in the Middle East, are naturally fractured. These reservoirs consist of two distinct elements, namely fractures and matrix, each of which contains its characteristic porosity and permeability. Because of this, the extension of conventional methods of reservoir engineering analysis to fractured reservoirs without mathematical justification could lead to results of uncertain value. The early reported work on artificially and naturally fractured reservoirs consists mainly of papers by Pollard,l Freeman and Natanson,2 and Samara.3 The most familiar method is that of Pollard. A more recent paper by Warren and Root showed how the Pollard method could lead to erroneous results,4 Warren and Root analyzed a plausible two-dimensional model of fractured reservoirs. They concluded that a Horner-type pressure build-up plot of a well producing from a fractured reservoir may be characterized by two parallel linear segments. These segments form the early and the late portions of the build-up plot and are connected by a transitional curve. In our analysis of pressure build-up and drawdown data obtained on several wells from various fractured reservoirs, two parallel straight lines were not observed. In fact, the build-up and drawdown plots were similar in shape to those obtained on homogeneous reservoirs. Fractured reservoirs, due to their complexity, could be represented by various mathematical models, none of which may be completely descriptive and satisfactory for all systems. This is so because the fractures and matrix blocks can be diverse in pattern, size, and geometry not only between one reservoir and another but also within a single reservoir. Therefore, one mathematical model may lead to a satisfactory solution in one case and fail in another. TO understand the behavior of the pressure buildup and drawdown data that were studied, and to explain the shape of the resulting plots, a fractured reservoir model was employed and analyzed mathematically. The model is based on the following assumptions: 1. The matrix blocks act like sources which feed the fractures with fluid; 2. The net fluid movement toward the wellbore obtains only in the fractures; and 3. The fractures' flow capacity and the degree of fracturing of the reservoir are uniform. By the degree of fracturing is meant the fractures' bulk volume per unit reservoir bulk volume. Assumption 3 does not stipulate that either the fractures or the matrix blocks should possess certain size, uniformity, geometric pattern, spacing, or direction. Moreover, this assumption of uniform flow capacity and degree of fracturing should be taken in the same general sense as one accepts uniform permeability and porosity assumptions in a homogeneous reservoir when deriving the unsteady -state fluid flow equation. Thus, the assumption may not be unreasonable, especially if one considers the evidence obtained from examining samples of fractured outcrops and reservoirs. Such samples show that the matrix usually consists of numerous blocks, all of which are small compared to the reservoir dimensions and well spacings. Therefore, the model could be described to represent a "homogeneously" fractured reservoir. la this paper, the fundamental equation of flow

Jan 1, 1966

By Guan-zhou Qiu, Shui-shi Liu, Yu-feng Guo, Tao Jiang

"The preparation of high-quality synthetic ruitle from electric furnace titanium slag was systematically investigated by activation roasting followed by acid leaching process. The results showed that impurities such as Ca and Mg in titanium slag can be effectively removed and TiO2 grade of the product was markedly improved by the process. High-quality synthetic rutile containing 88.54% TiO2, 0.42% (CaO+MgO) was obtained under the conditions that roasted with 7.5%(wt) H3PO4 at 1000 oC for 2h, followed by two-stage leaching in boiling dilute sulfuric acid for 2h. Mechanism studies showed that anosovite solid solution and silicate minerals were reacted with phosphoric acid in the roasting process. As a result, titanium components in titanium slag turned into rutile (TiO2) and impurities were transformed into acid-soluble phosphate and quartz.IntroductionWith the gradual depletion of natural rutile and the rapid development of titanium industry in China, the natural rutile reserves cannot satisfy the requirement for production of titanium pigment and titanium sponge. Ilmenite is, therefore, becoming main raw material for titanium industry. However, because of its low TiO2 grade, it generally requires preconcentration to titanium-rich material such as titanium slag or synthetic rutile [1-3].Ilmenite resources are extremely rich in Pan-xi area of China, which account for 90.54% of total ilmenite reserves in China [4]. The titanium slag produced by electric smelting of ilmenite concentrate has high contents of Ca and Mg, and is not suitable as a raw material for chloride process and titanium sponge production. Therefore, upgrading titanium slag to prepare raw material suitable for chloride process and titanium sponge production has important significance for the development of China's titanium industry."

Jan 1, 2011

By A. E. Dwight

Lattice parameters were determined for eighteen equiatornic alloys of the CsCl-type structure, ten of which were previously un-reported. It was found that fomation of the CsCl-type structure in binary alloys of the transition elements is largely dependent on position of the elements in the periodic table. The relative size of the two elements was not found to be a controlling factor. A recent paper by Beck, Darby, and Arora1 corre-lates the occurrence of CsC1-type ordered structures with the position of the constituent elements in the periodic table for the first long period. It was also suggested that a definite increase in relative bond strength between unlike atoms occurred when, in binary alloys of iron-group elements, the other component is changed from a chromium-group element, to a vanadium-group element, to titanium. A later paper by Philip and Beck2 noted that the lattice contraction increased in the order CrFe, VFe, and TiFe. It was also noted by Philip and Beck2 that the lattice contractions of CsC1-type alloys decreased in the order: TiFe, TiCo, and TiNi, which is an apparent reversal of the contractions expected from the position in the periodic table. It was suggested that the increasing lattice contraction is an indication of increased stability, i.e., greater A-Bbond strength. The present investigation was carried out to determine whether the relation of the position in the periodic table to the formation of the CsC1-type structure was also correct for alloys involving the second and third long-period elements. A systematic search was made for CsC1-type structures among equiatomic alloys and for those found, the lattice contraction was determined. EXPERIMENTAL TECHNIQUE The elements Y, Gd, Ti, Zr, Hf, V, and Cb are designated the A group and the elements Mn, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, and Au are designated the B group. Equiatomic alloys were prepared for 57 AB combinations. The alloys were arc melted in a multicrucible furnace3 in buttons ranging from 5 to 20 g. Chemical analyses were not made, as the charge weights agreed closely with those of the buttons after melting. The alloy buttons were homogenized at 800° to 900°C. Metal log raphic and X-ray specimens were prepared and heat treated at temperatures from 600° to 1200°C. Specimens for X-ray diffraction were usually ground to a powder in an agate mortar; however, needle-shaped solid specimens were used when the alloy was sufficiently ductile to permit their preparation. Diffraction patterns were taken with a Straumanistype Debye-Scherrer camera using filtered Cu or Co radiation. The lattice parameters were obtained in A by plotting the calculated a0 values against the cos29/sin 0 + cos2?/? function and extrapolating linearly to ?= 900. Metallographic control specimens were polished on cloth wheels with diamond paste and etched with various phosphoric and nitric acid reagents. RESULTS The eighteen equiatomic alloys listed in Table I gave evidence of a cubic structure with two atoms in the unit cell, although two of these cubic structures exist only at elevated temperatures and transform to a tetragonal structure on quenching. Nine of these eighteen alloys gave diffraction patterns with super-lattice lines showing that the structure is of the CsC1-type. The lack of superlattice lines in patterns of the other nine alloys may be attributed to the small difference in atomic scattering power of the components. Metallographic study indicates the occurrence of nine narrow single-phase fields at the AB composition. Any or all of these nine may also have a CsC1-type structure. The VFe alloy was found to have a CsCl-type structure by Philip and Beck2 through the use of CrKa radiation (for which the scattering factor of V is anomalously low), whereas the Cu radiation used

Jan 1, 1960

By Kenneth S. Johnson

Oklahoma is a region of complex geology where a mobile belt of Paleozoic geosynclines and uplifts on the south abuts against the margin of the North American craton to the north. The state contains many classic areas where fundamental concepts of sedimentation, stratigraphy, structural geology, historical geology, mineral investigation, and petroleum exploration have been formulated through the years. In the southern Oklahoma mountain belts, there are exposed a great variety of igneous and sedimentary rock units seen at few other places in the Midcontinent area. Major geologic provinces of Oklahoma (Fig. 1) include: (1) the cratonic and relatively stable northern shelf areas, including the Ozark uplift; (2) the Ouachita geosyncline (now the Ouachita Mountain belt) and associated Arkoma basin in the southeast; and (3) the southern Oklahoma aulacogen (geosyncline), comprising the area of Anadarko, Ardmore, Marietta, and Hollis basins, as well as the Arbuckle and Wichita Mountain uplifts. The three principal fold belts, the Ouachitas, Arbuckles, and Wichitas, all originated from a series of Pennsylvanian orogenies (about 300 million years ago) in the two Paleozoic geosynclines.

Jan 1, 1999

By Huaiyang Zhou

It has been long known that manganese nodules occur more or less in some part of marginal seas in West Pacific Ocean. On the other hand, it is difficult to understand their distribution and the genesis as those nodule samples were collected mostly by dredge from the deep basins generally has much higher sedimentation rate than the open ocean. For example, the sedimentation rate in the South China Sea is about three orders of magnitudes than that in region of the Clarion-Clipperton Fracture Zone. In June of 2013, a small seamount (named as Jiaolong Seamount), consisting of southern part and northern part with a distance of about 3 km each other, was visited by DSV Jiaolong/RV XiangYangHong 9. It is discovered that abundant manganese nodules exist only on the surface sediment in the southern part with a water depth of about 3800 m to 3300m, on the platforms nearby an obvious crater where volcanic rocks exposed on the wall. There are no any nodules be observed on the sediment in the northern part of the seamount (about 100 m deeper than the southern part) and surrounding deep basin (approximately 4000 m in water depth). It is speculated that a source of core for manganese nodule and a dynamic sedimentation environment, are two major governors for the growth and distribution of manganese nodule in the marginal seas.

Sep 14, 2011

By Rashkovski GB

Until recently amalgamation has been the main process forextracting large gold particles from gravity concentrates obtainedduring the dressing of ores and placer gold deposits.Development of new technology for treating the gravityconcentrates was necessary because of the harmful effect ofmercury on subsequent production processes and theenvironment. The harmful effect of mercury is particularlyevident in the resin-in-pulp process that is widely applied inRussia.

Jan 1, 1993

The President was authorized to appoint. a liaison committee to cooperate with the American Mining Congress in respect to the establishment of a Secretary of Mines and Mining in the President's Cabinet. He appointed Edwin Ludlow, Chairman; Mark L. Requa, and J. E. Johnson, Jr. It was resolved to accept the invitation from the Chicago Section to hold the. 120th meeting of the Institute in Chicago during the week of Sept. 15, 1919. The action of the Executive Committee in appointing Past President E. Gybbon Spilsbury as representative of this Institute to visit France upon the invitation of the Société des Ingénieurs Civils de France was approved. The final budget for 1918 was approved. Tile President was authorized to appoint a committee, of three members, on the Development of Activities of the Institute. The committee was requested to report at the February meeting of the Institute, and the Secretary was requested to invite each local section to have a member present to discuss the subject. The President appointed J. W. Richards, Chairman; P. N. Moore, and Allen H. Rogers. Thirty-six members, ten associates, and five junior associates were elected; one change of status from associate to member was granted; two members were reinstated; and eight resignations were accepted. An extension of time was granted to nine members. The dues of eight members were suspended on account of their being in active service.

Jan 2, 1919

By T. T. Natarajan, Nagy EI-Kaddah

"Numerical simulation of electromagnetic confinement systems generally requires large CPU time due to the strong coupling between the electromagnetic and the free boundary problems. The present paper examines the accuracy and the computational efficiency of the most common numerical schemes used in modeling such systems. Levitation melting was taken as a test case. In this study, a comparison was made between the finite element and surface integral methods for electromagnetic field calculations. The computational efficiency of Lagrange and the modified Hestenes methods for solving the free boundary problem were investigated. The convergence of the Lagrange method was found to be much faster than the modified Hestenes method. It was also found that finite element method not only gives accurate solutions, but faster convergence to the final equilibrium shape than the surface integral method. The applications and the limitations of these techniques in modeling electromagnetic confinement systems will be discussed.IntroductionIn recent years there has been a growing interest in the use of electromagnetic forces for confinement of molten metals as a means to eliminate molten metal contamination during melting and to improve surface quality of cast products. Continuous casting of metal without contact of a mold is now a reality, and is being commercially applied for casting of aluminum slabs /1/, and copper rods /2/. New applications of electromagnetic confinement in melting and casting include containerless melting (Magnetic Suspension Melting) /3/, edge containment in twin roll casting, and meniscus shape control in continuous casting of steel /4/.Modeling of confinement systems involves the determination of the electromagnetic field and the equilibrium shape. These two problems are strongly coupled due to the dependence of the field on the shape of the melt. While significant advances have been made in computational electromagnetics /5/, the application of developed computational techniques to electromagnetic confinement problems is not a simple task. The principal difficulty in using these methods is that the solution domain is not known a priori. due to coupling between the electromagnetic field and the free boundary problems. These two problems have to be solved simultaneously, leading to an iterative solution procedure. As a result, numerical simulation of electromagnetic confinement systems are computationally intensive with computational time at least an order of magnitude larger than the fixed domain problems."

Jan 1, 1994