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By B Davis, M Wallace, J Stewart, C F Burrett, J B. Cannell

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Sepon district in Lao PDR contains 1.8 Mt of JORC (2012) compliant contained Cu resources in addition to >4.5 Moz of Carlin-like Au in a Palaeozoic sedimentary package. The Cu deposits are proximal to an EW lineament of Permian rhyodacite porphyry (RDP) intrusive centres that are characterised by intense barren quartz stockworks. The Khanong deposit (42 Mt at 3.0 per cent Cu mineral inventory) is a carbonate replacement intermediate sulfidation deposit verging on a high sulfidation environment, where abundant pyrite, copper sulfides (chalcopyrite, bornite, trace enargite), copper sulfosalts (including tennantite – tetrahedrite, colusite), and base metal sulfides (sphalerite and galena) have replaced low dipping dolomite and limestone layers, forming a manto-style orebody fed by steep dipping intensely silica-pyrite altered structures. The Thengkham deposits (54 Mt at 1.5 per cent Cu) are composed of prograde skarns (garnet, clinopyroxene) and mineralised retrograde skarns (chlorite, magnetite, hematite, epidote, sericite, talc, serpentine, carbonates, sulfides) which are irregularly and semi-continuously distributed around an elongate 4 km long intrusive centre. Thengkham and Khanong have been strongly supergene enriched, forming secondary chalcocite breccias and exotic malachite zones.The Carlin-like Au deposits display a range of stratigraphic and structural controls and lie outboard of the Cu deposits. Similar structural controls, alteration assemblages and trace mineralogies suggest that gold and copper mineralisation are temporally and genetically related. It is hypothesised that the differences in style of Cu and Au deposits across the Sepon district are related primarily to palaeodepth and proximity to the intrusive centres.CITATION:Cannell, J B, Stewart, J, Williams, P, Wallace, M, Burrett, C F and Davis, B, 2015. The Sepon copper deposits (Laos) and their relation to Carlin-like gold mineralisation, in Proceedings PACRIM 2015 Congress, pp 399–408 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By John Ward Smith

Dawsonite-bearing oil shale of Colorado's Green River formation offers a unique and vast (more than 5.9 Gt of A120 j) resource of easily extractable alumina. The processing methods required by the thermal reactions of dawsonite and its oil-shale carrier also require production of shale oil, soda ash, and nahcolite as marketable coproducts. These production methods are presented. The alumina production process is contrasted with the Bayer process to describe technical advantages of extraction of alumina from oil shale which may offset the problems associated with processing a relatively lean ore. While alumina production from oil shale requires development of new technology, the technical problems appear solvable. Only the political problems arising from the now onerous and completely unnecessary federal oil-shale withdrawal appear less solvable.

Jan 1, 1982

Reduce permanent hearing losses to bulldozer operators. Approach Two types of noise control packages have been developed, that can be readily fabricated and installed into bulldozers by mine personnel. How It Works Both of the noise control packages reduce the noise exposure of the operator by two techniques, blocking the noise paths or absorbing the sound before it reaches the operator. Both airborne noise paths and noise paths through the machine are blocked. One noise control package is designed for bulldozers having ROPS (Roll Over Protection System), but no cab. The other package is designed for bulldozers having ROPS

Jan 1, 1981

By Michel C. Frippel

This section of the Minerals Yearbook reviews the minerals industries of 29 countries: the 12 nations of the European Community (Belgium, France, the Federal Republic of Germany (FRG), Italy, Greece, the Netherlands, Denmark/Greenland, Spain, Portugal, Luxembourg, The United Kingdom, and Ireland); 6 of the 7 nations of the European Free Trade Association (Sweden, Norway, Finland, Iceland, Austria, and Switzerland); Malta; the 8 Centrally Planned Economies of Eastern Europe (the German Democratic Republic (GDR), Poland, Yugoslavia, Albania, Hungary, Czechoslovakia, Romania, and Bulgaria); and the U.S.S.R. Western Europe Western Europe [loosely defined to include the 12 nations of the European Com-munity (EC) and the 7 nations of the European Free Trade Association (EFTA)] is the single largest trading area and consumer of raw materials in the world. If Western Europe was at one time an important mining sector, it has now increasingly relegated the role of supplying minerals for its minerals processing industry to its ex-colonies in North and South America, Africa, and Australia. In this regard, Western Europe is the most important determinant of raw materials consumption (and thus, indirectly, raw materials production). There is an important reason for this since Western Europe lies somewhere between Japan at one extreme and the United States and the U.S.S.R. at the other extreme as regards the availability of natural resources.

Jan 1, 1992

By Richard L. Sayrs

The Eve Mills deposit is in Monroe County, Tenn., near the southeastern corner of the State. The deposit was examined in February 1943 by a Bureau of Mines engineer, and drilling the property was recommended to increase the on: reserves enough to justify mining should war needs require it. The deposits were explored, by 32 diamond-drill holes totaling 11,649 feet during the periods from July 1943 to November 7, 1945, and from April 1944 to August 17, 1944. The drilling campaign disclosed a large area of mineralization. The ore, however, is apparently confined to long, narrow sheets. The indicated grade of the ore bodies blocked cut by the Bureau of Mines is 4.o8 percent zinc and 2.10 percent iron.

Jan 1, 1949

By Javier Baladron, Mijail Villar, Brandt Henriksson

"In this presentation an overview will be given of what has been observed by the authors in the copper concentration industry, with a large diversity of tailing thickeners operating under different conditions, although many of them are located in the same neighborhood. A closer look will be taken at the reported performance from different sites and from different thickener designs, either conventional or high rate, including those that were retrofitted, regardless of the thickener brand. An analysis is also made of the generic correlation of the size of the thickener and the performance in terms of solids loading (or unit area) and % solids. The paper envisions a technology development route, makes a brief analysis of the economic impact of the suggested route and points out the need for development in technologies around tailings thickeners, such as automation, yield stress measurement, slurry pumping and construction methods."

Jan 1, 2014

By M. M. Fine

This report describes a Bureau of Mines technical feasibility study of simultaneous reduction and induration of pelletized iron ore to make a product with superior qualities as blast-furnace feed. Highly reduced, physically competent pellets can be made from magnetite and specularite concentrates that contain small additions of bentonite as binder. In batch tests, pellets were dried, surrounded with solid fuel in crucibles, and heated to the reducing temperature. Total iron content of the best products was higher than 80 percent and crushing strength of 1/2-inch metallized pellets ranged up to 600 pounds or more. Comparative tests of several commercial oxide pellets showed a wide range in crushing strengths, but most values were less than 350 pounds. Continuous tests in a rotary kiln resulted in the same degree of reduction, but the pellets had lower crushing strengths because of the limitations in the maximum operating temperature of the small kiln.

Jan 1, 1962

By Donald A. Dahlstrom

The selection and sizing of filters depends on the characteristics of the type of filter and the feed slurry. In addition, the rate functions of cake formation, cake washing and cake dewatering must be determined in order to design the filter station on the basis of desired performance. This chapter discusses the applied theory used to determine the rate functions and illustrates how to incorporate these into the filter cycle to obtain the required objectives. This also permits the sizing of the filter and auxiliaries as well as the selection of the proper type of filter.

Jan 1, 1978

By P Valenzuela

Joint mapping is a fundamental input for rock mass characterisation and slope stability analysis. The usual way to do it is using a compass in the field or digitising structures on a screen, with a software package.In this paper a method to identify and map joints automatically along a rock face is presented; it is called the Concentric Shells (CS) algorithm. The method scans a point cloud sequentially, tests if selected points are ‘true pivots’ within an inner shell, and then it searches for points inside a wider sphere (outer shell).The algorithm, developed by the author, was applied in real data. It reproduces the main features obtained from conventional (compass) and digital mapping (software package). Execution times are approximately 45 seconds for two point sets holding of 3.1 million points. Obtaining the same results via digital mapping takes approximately 3–4 working days.Key advantages of this method are: significant time reductions; elimination of mapping bias; and the ability to manage very large data sets (>2 million points) without the need of scanning the cloud on the screen. These advantages make this method an attractive tool for engineers and geologists wanting to increase productivity.CITATION:Valenzuela, P, 2017. Automated joint mapping using the concentric shells algorithm, in Proceedings Tenth International Mining Geology Conference 2017, pp 257–262 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

Recognizing the fact that the problems of the committee named by the Board to prepare the "official ticket" for officers and Directors of the Institute are various and difficult; and desiring to assist this committee by setting forth some of the principles that should guide the committee and some of the qualifications that should be required of candidates, the following instructions are formulated and the Secretary is directed to publish them in MINING AND METALLURGY concurrently with the publication of the names of each newly appointed Nominating Committee and to send a copy to each member of the Committee.

Jan 1, 1946

By Peter (Yunqing) Zhang

Longwall recovery under weak roof conditions could have considerable delay if the immediate roof is weak and deteriorates during screening. A pre-driven longwall recovery room is a feasible solution to minimize the impact of longwall move on production. In this longwall recovery project, a 16-ft recovery room was pre-driven to cover screening, and the shearer cut another 16 ft outby to reach the final recovery line. The pre-driven recovery room was carefully monitored as the face was approaching it. The longwall face operated very well as it cut into the recovery room. The recovery process took about 13 days, and considerable time was saved compared with the previous panel. The support in pre-driven recovery room was designed to handle both front abutment pressure and weak immediate roof conditions. Pumpable standing support was used to support the cantilevered roof as the fender pillar narrowed and collapsed when the face cut into the recovery room. To ensure the stability of the recovery room, 3-D computer modeling was used to evaluate the support system. Abutment pressure, critical fender pillar width, bolting system, pumpable cribs and shield support were considered in the model. The recovery room was carefully monitored during longwall recovery. Roof-to-floor convergence and crib convergence were recorded every shift as the longwall face was approaching the recovery room. Roof, floor and pillar activities and crib performance were also observed as the face cut into the recovery room. This paper presents the support design for the recovery room, evaluation of the support system through computer modeling, and details of the monitoring results.

Jan 1, 2006

By N. J. Grant, H. Brunner

This paber is concerned with the determination of equations relating elongation to the amount of shear taking place both along grain boundaries and in slip planes of poly crystalline aggregates during creep. Certain discrepancies with previously used equations are pointed out. Grain boundaries were observed to become serrated during creep, but it is shown that this does not necessarily prevent further grain boundary sliding. Direct obser-vations of subgrain boundary ingration lead to the conclusion that this migration facilitates sliding along serrated grain boundaries. It is bointed out that the state of stress at triple boints is still unknown. MOST of the mechanisms of deformation contributing to elongation are shear processes, such as slip, kinking, grain boundary sliding, and twinning. For quantitative investigations of individual deformation mechanism it is necessary to know the equation which permits the calculation of speci-tnen elongation from measured amounts of shear. This calculated elongation must then be compared with the observed total elongation. The authors' special interest concerned grain boundary sliding during creep. Although this subject has already been investigated quantitatively by McLean,' Rachinger,' and Fazan, Sherby, and Dorn, calculations indicated that none of the equations used thus far to relate shear with elongation were sufficiently well founded. A basic study of this relationship was thus made and the results of this study (which do not entirely agree with those previously used) are presented. Most of the ideas set forth apply not only to grain boundary sliding but to other mechanisms of shear as well. THE SPEAR-ELONGATION RELATIONSHIP Basic Models—The relationship between shear and elongation is trivial in the simplest case of shear, which is shown in Fig. l(a). The vector A; designates the displacement across the shear interface, and Au, and Aut are its components parallel and normal to the tensile direction, respectively. It is evident that the specimen elongation due to shear is equal to the longitudinal component of the shear vector, and it should be noted that the normal component does not contribute to the elongation of the specimen (there are, of course, two normal components in a three-dimensional model). The model shown in Fig. l(b) may be applied to mechanical twinning and to subgrain boundary tnigration. In this case the width (h) of an already existing shear band increases by the migration of an interface, but the shear angle y (angle of mis-orientation in the case of a subgrain boundary) remains constant. The geometrical relationships indicated in Fig. l(b) permit this case to be reduced to the one shown in Fig. l(a). For the resulting elongation A6 we find: where AV/V = fraction of the volume of the specimen swept by migrating interfaces , and 1 = length of specimen. Thus, assuming for example that the angle of mis-orientation is 1 deg, and that P = 45 deg, we find that the specimen elongates 0.87 pct of its length if the entire volume of the specimen is swept once by such a subgrain boundary. An example of deformation by migration of subgrain boundaries is shown in Fig. 2. The specimen shown was repolished after 9.8 pct creep strain and the test then continued for another \ pct. Since the shear vector has, in general, a component normal to the surface, subgrain boundary migration results in the formation of an inclined band delineating the region swept by the subgrain boundary. These inclined bands become clearly visible when observed with oblique illumina-

Jan 1, 1960

By H. Clare Horwood

"Two structures, a fracture zone and a shear zone, contained the two orebodies that yielded all the ore mined at the Gold Eagle mine. The orebodies are known as the Gold Eagle vein and the No. 1 shear zone. Both structures occur close to contacts between Timiskaming sediments, Algoman diorite, and later Algoman granite-granodiorite. The structures were produced by compressive forces from a south direction acting in the southern part of the McKenzie-Gold Eagle stock and in a cylindrically shaped inclusion of Timiskaming sediments.The mine, which exhausted its ore reserves and ceased operations in September of 1941, is on the east side of Mackenzie island, in the centre of Dome township in the Red Lake area.The Gold Eagle vein was located during the summer of 1933 by a surface exploration programme carried out under the direction of Alex Gillies. Sub-· sequent diamond drilling and underground exploration led to the installation of a mill, which came into production in October of 1937. The No. 1 shear zone was discovered and explored later from a drive on the 500-foot level. The mine produced a total of 40,204 oz. gold and 19,157 oz. silver from 223,628 tons of ore hoisted (180,095 tons milled) during its 4 years of mill operation.GENERAL GEOLOGYThe ore-bearing structures trend S.61°E. across Timiskaming greywacke, Algoman diorite, and later Algoman granite-granodiorite. The greywacke is a large, cylindrically shaped mass that is separated from the mai~ mass by the later intrusives. It is a massive, light-coloured, quartzose variety that has been recrystallized by the enclosing granite. The diorite and the granite-granodiorite are early and late components of the McKenzie-Gold Eagle stock. The diorite, which is a porphyritic rock containing large crystals of andesine-labradorite surrounded by hornblende, was injected early in the Algoman period. It was intruded and in large measure surrounded by the later granite-granodiorite. This rock varies from a granodiorite near the mine to a granite in the centre of the stock. All three intrusions are massive and homogeneous."

Jan 1, 1954

By E. Dadzie

This paper will review some methods used to manage geotechnical risk at Damang Pit Cutback. The pit depth is designed up to 250m with push back on the eastern and western walls of the existed and depleted Railway Cutback (RCB) pit. The geotechnical design was presented by SRK Perth, focussing on the optimisation of the bench face angle which finally evolved with ?steep slope strategy?; 24m at 800 and 24m at 750 on the eastern and western walls respectively. The east wall was designed strategically to optimise the proximity of the tailings dam to the final pit crest of the push back. The pit has experienced failure in the weathered profile transgressing through the transitional material into the fresh rock at different location of the east wall since development in July 2005. To ensure stability and to minimise ore loss, the east wall has been redesigned using 700 batter angles and reduced berm width of 4m compared to 800 and 8.5 berm width of 24m bench height. The paper will also discuss how slope failures to the east wall had been sustained, managed and monitored to enhance production. Emphasis is placed on slope management at Damang which includes the principles of wall control blast, visual inspection, slope depressurisation and the state-of-the art of slope monitoring using Autoslope automated prism monitoring. Future slope monitoring is considering the use of 3D Laser and Radar to provide early warning so that evacuation could be effected. The intension is to provide mine personnel the means to identify risk areas during mining activities.

Jan 1, 2008

By Gordon Miner

GENERAL DESCRIPTION At the Star mine, Hecla Mining Co., located in Burke, Shoshone County, ID, the mining method is horizontal slicing (timbered or untimbered) cut-and-fill using hydraulic sand backfill. Back stoping as well as breast stoping is used; see Fig. 1. The annual produc¬tion from all cut-and-fill mining is 259 816 t (286,400 st). The average depth ranges from 366 to 2408 m (1200 to 7900 ft). A majority of the tonnage comes from an average depth of 2240 m (7350 ft). Average travel time to the stope is 1 hr. GENERAL ORE BODY REQUIREMENTS AND LIMITATIONS Size and Ground Conditions The ore body is 610 to 1219 m (2000 to 4000 ft) along the strike and 2408 m (7900 ft) on the dip, with an average vein width of 2.6 m (8.5 ft). The dip is essentially vertical. The ore body is heavily sheared and broken on the main fault structures; it is more competent on the wall veins but everywhere subject to rock bursting at depth. The hanging and footwalls are strongly fractured on the main fault structures, again more competent but still fractured on the wall veins. All host rock is Revett quartzite. Value and Production Requirements The ore value is $56 per ton. Production require¬ments are 1089 t/ d (1200 stpd), five days per week. Why Cut-and-Fill? The slusher extraction method is the most satisfac¬tory and practical for narrow vertical veins with sheared walls. The method must be quite selective to be com¬mercial. The veins are too narrow for rubber-tired ex¬traction and the grade is not high enough to make resuing practical. DETAILED DESCRIPTION Development Access to the main shaft is by the 3.2-km (2-mile) main haulage tunnel. The level intervals in the vertical timbered shafts are 61 m (200 ft). Vein development is by crosscut and laterals located 30.5 m (100 ft) into the vein wall. Vein crosscuts are on ±61 m (200 ft) centers. Access to the vein is by raises carried up with the stope. The raises are equipped with four wood¬cribbed chutes (two orepasses reinforced with angle irons, one manway, and one timber slide, Figs. 2-6). The initial cut is located 6.7 m (22 ft) above the main level (Fig. 1). Stoping Cycle Detail Sampling: Grab samples are taken from the mine cars. Channel sampling of the faces and backs is done when necessary. Drilling: For stope drilling, Ingersoll-Rand 300M percussion drills are used, with Ingersoll-Rand 300M and Gardner-Denver RB83M stopers, used for back stoping. Breasting down is done with Gardner-Denver S83FM jacklegs. The back stoping rounds are 0.9 to 1.8 m (3 to 6 ft) and the breast stoping rounds 1.5 to 3m (5 to 10 ft). Blasting: For stope blasting DuPont Tovex 100 watergel with fuses and igniter cord is used primarily. Approximately 60% of the blasting is done with am¬monium nitrate-fuel oil (ANFO). For development headings and shaft sinking, DuPont Drivex watergel with Ensign Bickford Nonel Primadet primers is is used. Mucking: Broken ore is removed entirely by slusher in the stopes. These are mostly 3.7-7.5-kW (5-10-hp) Ingersoll-Rand air-powered or 7.5-37.3-kW (10-50-hp) Ingersoll-Rand electric-powered. In the horizontal de¬velopment headings Eimco 12B and 21 and Atlas Copco LM-56 overshot mucking machines and a 0.76 (1 cu yd) hydroelectric Wagner HST-1 LHD (load-haul-dump) unit are used. Rockway for Extraction: The cribbed chutes (Fig. 7) are nearly vertical and hexagonal in shape and are made of spaced 152 x 203-mm (6 x 8-in.) timber, reinforced with varying weights and sizes of angle iron, depending on wear requirements. Rectangular cribbed chutes are used where ground pressure is not a problem. Cribbing is added in 2.4 or 3-m (8 or 10-ft) extensions accord¬ing to the floor height (whether timbered or untimbered). See Figs. 8 and 9. Backfilling: Backfilling is done with hydraulic sand consisting of classified mill tailings at 65% solids. The fill contains approximately 20% 325-mesh fines. The tailings are pumped 3353 m (11,000 ft) at 50-55% solids 22.7 dry t/h (25 dry stph) with a duplex piston pump. Cycloning increases the tailings density to 65% solids. Fill storage is in a 998-dry-t (1100 dry st) agi

Jan 1, 1982

By Walter Fuchs

IT is now generally conceded that coal is the product of deposition and transformation of debris of forests and swamps.29 Ample data are available to illustrate the metamorphosis of biochemical substances through biological action; other data show the progressive regional metamorphism existing in coal beds ;25 and numerous examples of change effected by intrusion of igneous dikes into coal deposits have been established.23 However, often the relative importance of the biological and the geological factor in determining the character of the various natural coals is a debatable question. Since both biological and geological factors are ever present in nature, the problem, at first glance, would appear to resemble certain probability problems: specifically the simultaneous toss of two coins, with the biological factor as heads and the geological as tails. The probability is 2 : I for the combined effect of both factors, as compared to the exclusive effect of either one, if the a priori probability is the same for each factor. This condition can be analyzed by a thermodynamic treatment of data, which may be obtained from a consideration of pertinent biological, chemical, geophysical and geological facts. SYNOPSIS OF BIOLOGICAL AND CHEMICAL FACTS The biosphere is not sterile; i.e., microorganisms are always present. Microorganisms have been established in the ocean deep, under the ice of the polar regions, in the sand of the deserts, and in swamps far below the surface. The various biological media may be acid, neutral, or alkaline, and they may or may not be readily accessible to air. Microorganisms are encountered almost everywhere, except where the temperature is not within the range tolerable by microbial life. Of course, with changing conditions, the type of microorganisms will change. All chemical products of life-proteins, fats, carbohydrates, lignins, waxes, resins may serve as a habitat of microorganisms. In the decomposition of a medium. some microorganisms macerate organic matter mechanically and remove certain constituents for their own nutrition; others decompose a large part of the organic matter but may leave certain constituents undecomposed. Some attack only certain specific ingredients of the organic matter. All of them build up cell substance. The nitrogen content of the medium largely determines the degree of decomposition. Below 1.7 per cent nitrogen, growth of microorganisms and hence decomposition of organic material is retarded; consequently organic material will accumulate.17, 32 Such accumulations of organic material may give coal eventually. Coals differ in type and rank. The nature of the original vegetation and the conditions attending the transformation of the accumulated debris determine the type of coal such as bright, splint, cannel, and algal or boghead coals. Chemical analysis of representative samples of a given type of

Jan 1, 1941

By C. W. Chao, M. Melashvili, F. Hilário

The processing of a bulk concentrate containing copper as chalcocite, enargite, bornite and chalcopyrite along with pyrite and precious metals of silver and gold was studied. A leaching study was undertaken to examine the application of the atmospheric acid leaching process to a bulk copper concentrate for copper recovery followed by cyanidation or thiosulfate leaching for gold and silver recovery. The extraction of copper exceeded 90% under some conditions and the recovery of gold and silver reached a maximum of 44 and 45%, respectively. A sample of bulk concentrate was roasted in air to oxidize the sulfides with release of sulfur dioxide followed by acid leaching of the roaster calcine and cyanidation of the acid leach solution. The copper extraction reached over 92% and the gold extraction exceeded 88%. The sulfur dioxide may be captured for acid production. INTRODUCTION The processing of a large primary copper deposit in Indonesia is under investigation. One of the possible routes for processing involves flotation of a bulk copper-gold concentrate followed by treatment by an atmospheric leach/SX-EW process for copper recovery. The atmospheric leach residue would then be leached for recovery of gold and silver. A second route involves roasting of the concentrate followed by acid leaching and SX-EW for copper recovery. The leach residue from the roaster calcine would then be leached for recovery of gold and silver. The roaster off-gases could be used for sulfuric acid manufacture, enabling the production of a valuable by-product. The Cobre Las Cruces (CLC) process (Munoz, Garcia, & Delgado, 2017) was designed to treat a resource of copper discovered close to Seville, Spain. The process was developed by Outotec with MK Gold (original project owner). INMET Mining subsequently purchased the deposit from MK Gold and built the copper processing facility. The CLC process is similar to the Mt. Gordon Copper process; except that OKTOP reactors have been installed instead of a low temperature, low pressure autoclave process. The plant was designed to treat 1.3 mtpa of ore at a grade of 6.2% Cu to produce 72,000 tpa of cathode copper over a 15 year project life. The main gangue mineral at Cobre Las Cruces was pyrite. The Cobre Las Cruces ore is therefore similar to a rougher flotation concentrate containing copper minerals and pyrite. The roasting of a rougher flotation concentrate can be designed to produce hematite, basic copper oxides and sulfur dioxide off gas. The acid leaching of the basic copper oxides may produce soluble copper for SX-EW recovery of copper. The sulfur dioxide off-gas may be used to make sulfuric acid.

Jan 1, 2019

By Shan He, Qiang Wang, Xuling Chen, Min Gan, Lishun Yuan, Xiaohui Fan

"The sintering properties of vanadium-titanium magnetite concentrate(VTC) was studied in this paper. Through the optimizing the sintering process of VTC, the suitable granulation moisture and coke proportion were determined. The sintering velocity decreased from 23.05 mm/min to 18.22 mm/min. With the increase of VTC proportion from 0 to 46%, the specific productivity and tumbler index were respectively decreased from 1.55 t/(m2·h) to 1.21 t/(m2·h), and 62.93% to 57.73%. The temperature of liquid phase formations of mixtures increased, the amount of liquid lowered, and the content and sharp of sintering mineral gradually changed with the increase of VTC ,these lead that sinter quality became worse.IntroductionIn recent years, the steel industry of China is developing rapidly. And the steel production was 627 million tons in 2010. At present, the resources of vanadium-titanium magnetite concentrate(VTC) was about 14.4% of the total national iron reserves of China[1]. VTC has been used as sintering material by Magang, Chenggang and Pangang. The amount of VTC in Pangang is maximum. However, there exist many problems in VTC sintering, which involve in high specific productivity, bad sintering tumbler strength and high energy consumption[2~5]. That’s why the proportion of VTC is limited in sintering.The high quality of iron ore resources is worse in China. Therefore, it’s necessary to study the properties of VTC sintering, and to find out the reason how the VTC ratio affect the sinter performance. Purpose and significance of the research is to get high-quality sinter with the proportion of VTC greatly raised."

Jan 1, 2012

By B. K. Larkin, H. K. van Poollen, H. C. Bixel

A detailed treatment is given of the transient pressure behavior of a well located near a linear discontinuity. On either side of the discontinuity, the values of permeability, viscosity, compressibility, and porosity are uniform, but may be different from those on the other side of the discontinuity. These results generalize previously published works which assumed the permeability ratio for media on different sides of the discontinuity was zero, one, or infinity. One application of this material would be to facilitate detection of facies changes or fluid-fluid contacts by transient testing. Solutions, presented graphically, show pressure decline for constant rate fluid production. The range of variables examined includes dimensionless time from 0.1 to 100, rnohility ratio from 0.001 to 1000 and specific compressibility ratio from 0.001 to 1000. For dimensionless tinze less than 0.4, the pressure behavior is essentially that of a well in an infinite reservoir. Thus, reservoir properties near the well may be estimated in the usual manner. Using an overlay technique to match an experimental curve with one of the theoretical curves, it is possible to estimate the distance to a discontinuity by substituting the actual time t and the corresponding dimensionless time , at which a match occurs into the equation where is the diffusivity near the well, and may be estimated from data taken at early time. Because of both the complexity of the solutions and limited computer facilities, well interference problems were not examined extensively. However, it was found that well interference may be masked by the discontinuity in some cases. By superposition of the results of constant rate fluid production, the problenz of pressure buildup may be treated. Such results show that for early shut-in times correct values for the transnzissibility are obtained from conventional semilog plotting. However, erroneous values of the static reservoir pressure are obtained unless data at large shut-in times are taken. INTRODUCTION Transient well testing has yielded estimates of such reservoir parameters as static reservoir pressure, permeability. porosity, and well bore effects. In most tests, it was assumed that the reservoirs were homogeneous and iso-tropic. Anisotropic media' and radial discontinuities were considered.'.' Various studies have been made on multiple-layer reservoirs." ' Linear discontinuities have been described for problems of one-dimensional flow.' In the present paper, a mathematical treatment is given for a well located near a linear discontinuity in an otherwise infinite medium (see Fig. 1). An actual reservoir analogy would be a well in a relatively thin reservoir near a fluid-fluid contact, or a well located in a reservoir exhibiting a sudden change in rock and formation characteristics, such as thickness, porosity, or permeability. A sudden change in porosity or permeability may be caused by clay fill or other types of facies changes. Sudden thickness changes niay be the result of such geological formations as buried shore lines and channel deposits. In otherwise uniform formations, a linear discontinuity may be caused by fluid-fluid interfaces such as oil-water contacts. 3s-oil contacts, or gas-water contacts.

By W. H. Young

THE BITUMINOUS coal and lignite industry increased substantially in 1962, compared with the 1961 figures. The major items of production, consumption, exports, and productivity increased. However, certain key items declined. The steady upward trend in mechanization failed to materialize for the third year; the percentage of total tonnage mechanically loaded remained the same as in the 2 previous years; and the tonnage mechanically cleaned was smaller than in the previous year. The percentage of total production mined by stripping and by augers increased slightly. Most significant was the continued decline in average value and employment. Production.-The output of bituminous coal and lignite in the United States in 1962-422 million tons-was 5 percent greater than the 403 million tons produced in 1961. Production was greater in 1962, owing largely to expanded consumption by the electric utilities and to more exports.

Jan 1, 1963