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By M. A. Mahtab, T. M. Yegulalp

This paper presents the development and application of an approach for clustering fracture orientation data. Data are projected on the surface of the unit upper hemisphere and the clustering approach is applied in three steps: (1) randomness test and identification of dense clusters, (2) estimation of cluster statistics, using Bingham distribution, and (3) rejection of extremal data based on Chauvenet's criterion.

Jan 1, 1982

By Charles F. Johnson

A pulse technique is described for the measurement of bar velocity. A low frequency sine wave pulse is used which allows the wave-length to become much larger than the lateral dimensions of the test specimen. The low frequency pulse method has been tested and compared with the resonant frequency method and the results show that both methods give, on the average, equivalent velocities.

Jan 1, 1971

By John C. F. Randolph

This establishment being now in full working order, it has seemed of considerable professional interest to collect together, in a concise form, the various points as to its plan, method of dressing, and equipment. The data contained in this paper have been largely drawn from the able paper of E. Kutscher, constrnoting engineer of the works, contained in the Zeitschrift fur Berg-HÜtten-und Salinenwesen im Preussischen Staate, 1873, supplemented by some personal memoranda made while the works were under construction and by memoranda on the works appearing in various German technical papers from their completion up to date. This is probably the largest dressing works in the world devoted to the beneficiation of argentiferous lead ores, and it is doubtful if any establishment for the concentration of mineral of any description can compare with it in size. As showing the final practice adopted in an old and very conservative mining region, in which the concentration of ores has been a matter of constant practice and experiment for a very long period, these works are of peculiar interest. The fact that the Clausthal ores strongly resemble a very large and abundant class of ores found in the United States has always attracted the attention of American mining engineers and mine owners to the methods employed in dressing and smelting them. The study of their methods of concentration of ores has, however, always been full of difficulty,

Jan 1, 1879

By Shiou-Chuan Sun

THE fact that coals of different ranks and even of the same rank differ greatly in their amenability to froth flotation is well known. In recognition of the need for an explanation of this phenomenon, two hypotheses have been suggested. Wilkins1 reported that the floatability of coals increased with an increase of the carbon content or rank. This postulate is handicapped by the fact that bituminous coals that possess moderate carbon contents are actually more floatable than anthracite coals that have high carbon contents, as shown in columns 6 and 9 of Table I. Taggart and his associates' implied that the difference of floatability between bituminous and anthracite coal was caused by the variation of carbon-hydrogen ratio. This is not applicable to the relative floatability of other coals and carbons. For example, column 11 of Table I shows that the carbon-hydrogen ratios of low-floating lignitic coal and non-floating animal charcoal are not only smaller than the moderate-floating anthracite coal, but are also similar to the high-floating bituminous coal. Furthermore, according to this hypothesis, high temperature coke-A (464), Ceylon graphite (1238), and lamp-black (357), all possessing extremely high carbon-hydrogen ratios, should be less floatable than other substances having much lower carbon- hydrogen ratios such as high volatile-B bituminous coal (11.9 to 22), anthracite coal (35.7 to 60.5), lignitic coal (15.6 to 33.6), and charcoal (13 to 26.2). However the former group is actually more floatable than the latter group.

Jan 1, 1954

By Margaret Dienes, Karl L. Fetters

IT is recognized that ingot structure is important in determining the quality of finished steel. Such elements of ingot structure as the size, shape and distribution of primary crystals; the size, shape and distribution of shrinkage cavities; the degree and kind of segregation (both macro and micro); the distribution of nonmetallic impurities and gas cavities are each the result of solidification phenomena. These structural features vary with variations in ingot practice: Their control requires a knowledge of their correlation with the variables of ingot practice. The structures of full-sized commercial steel ingots have been studied extensively by the Steel Ingots Committee of the Iron and Steel Institute.1 This work has contributed much to our knowledge of ingot structure and the factors that control it. These investigations of necessity have been limited in scope because of their costliness and the great amount of time required. Studies of the structure of small steel ingots have not been very satisfactory because of the rapid rate of freezing of the ingots. Their structures are thus difficult to resolve and to interpret. Medium sizes of steel ingots in the ranges of 150 to 500 lb. do offer opportunity for study, but their cost also becomes greater and their use less expeditious. Experimental models for the study of steel-ingot structure have been made of nonferrous metals. Gathmann2 used lead-tin alloys and reported that they were satisfactory for determination of the location of the major shrinkage cavities and the "planes of weakness" resulting from the pattern of crystallization. Certain features of mold design have been illustrated by these results. Bezdenezhnihk3 has used copper and aluminum ingots similarly and has shown the effect of mold-wall thickness on the depth of columnar grains. These studies of nonferrous models have been useful, but their results have been limited because the analogy with steel ingots obviously is not a close one. Model wax ingots have also been useful in pointing out important features of mold design. Gathmann4 watched the solidification of wax ingots, through a glass-walled mold, and has reported the effects of mold type on the location of the shrinkage cavities. Segregation was simulated by using a mixture of paraffin and stearine and adding a red dye that on freezing segregated preferentially to the stearine. Brearley5 also used wax models to determine .the effects of some of the principal features of mold design. Carlsson and Hultgren6 used stearic acid to show that the columnar crystals of ingots tend to slope upward progressively from the mold wall toward the center of the ingot. As with the nonferrous ingots, the wax ingots have

Jan 1, 1943

By J. Lyndon Rosenblad

The strength of a jointed-rock mass is not well-understood. It is believed, however, that the behavior of a rock mass is governed by both the intact rock properties and the properties of the discontinuities. Rock research in the past has been concentrated on the determination of intact rock properties. Several studies are presently underway which should provide more insight into the properties of the discontinuities. Few research programs, however, have been undertaken with the intent of studying the composite rock mass behavior where either the intact rock strength or the properties of the discontinuities may control failure. There are three approaches available for studying the behavior of a rock mass, namely, field studies, mathematical models (finite element), and geomechanical models. A geomechanical model has been developed in this study where the strength and failure modes of a model rock mass are studied as a function of intact block geometry, joint orientation, joint properties, and confining pressure. The objective of this study is to gain some insight into the parameters that govern the behavior of a rock mass, which parameters are most important, and when these parameters control. This chapter describes only one phase of the study, the development of equipment for use with the rock-blocks model. The models being tested are approximately 22 x 22 x 6-in. The size varies slightly depending upon the joint orientation used. The equipment developed includes model material molds, reaction frames, loading apparatus, measuring and recording instrumentation, and other accessory equipment pertinent to the operation of a successful study. The usual problems in equipment development, such as uniformity of load application, loading capabilities, and reaction capacities are all

Jan 1, 1970

By R. T. C. Rasmussen, L. H. Banning, W. E. Anable

In the rapidly growing industry of elemental-phosphorus production from western phosphates, most of the vanadium and chromium contained in the phosphate rock collect in the byproduct ferro-phosphorus. Results are presented of a completed laboratory project, which developed a tristage crystallization and hydrolysis process for recovering strategic vanadium and chromium, as well as a valuable phosphorus product, after extracting these elements from the ferro-phosphorus by roasting and leaching. THE Phosphoria formation in Idaho, Montana, Wyoming, and Utah contains the Nation's largest reserve of phosphate rock. A unique feature of the Phosphoria beds is their content of a fraction of a percentage each of vanadium, chromium, nickel, and molybdenum. Vanadium is the most important as to quantity and value. Small-scale tests by the Bureau of Mines at Albany, Oregon, in 1947, indicated that most of the vanadium in the phosphate rock collects in the ferrophosphorus product of smelting. Subsequent electric smelting operations to produce elemental phosphorus from western phosphate rock (experimentally by TVA and industrially at Pocatello, Idaho) have shown that the vanadium and other metals in the rock are to a large extent recovered in concentrated form in the ferrophosphorus byproduct. This paper reports the results of completed laboratory research on the recovery of vanadium from ferrophosphorus, which was undertaken by the Bureau of Mines at Albany in 1948 as the first phase of a project entitled, "Vanadium and Fluorine from Western Phosphates." The various vanadium-recovery methods investigated, including the roast-leach method that showed most promise and was studied in greatest detail, are discussed in an earlier publication.' Subsequent systematic study of the roast-leach method of extracting vanadium from western ferrophosphorus developed the more effi- cient tristage crystallization process, which is the subject of this paper. Process Development The investigations were made on ferrophosphorus produced in the electric smelting of elemental phosphorus from western phosphate rock. The TVA provided two sample lots of ferrophosphorus produced in pilot plant smelting of phosphatic shale from the Fort Hall Indian Reservation in Idaho. The Westvaco Chemical Div. of the Food Machinery & Chemical Corp. supplied two sample lots of ferrophosphorus produced by its phosphorus smelter at Pocatello, Idaho. The analyses of all four lots are shown in Table I. Westvaco lot B was the starting material for the more recent tests. The roast-leach process for recovering vanadium from western ferrophosphorus, as originally developed, employed the following principal steps: Roasting of a mixture of pulverized ferrophosphorus, soda ash, and salt; extraction of the water-soluble vanadium, phosphorus, and chromium compounds from the calcine by leaching, settling, and decanta-tion of the pregnant solution; primary crystallization of trisodium phosphate from the pregnant solution; purification of the trisodium phosphate crystals by dissolution in water and secondary crystallization; purification of the pregnant vanadium solution from the primary crystallization step by adding calcium chloride to precipitate calcium phosphate; and hydrolysis of vanadium red cake from the puri-

Jan 1, 1954

By A. L. Blomfield

THE Golden Cycle Mining and Reduction Co. operates its custom mill at Colorado Springs on Cripple Creek ores exclusively. These ores are straight sulpho-tellurides, with practically no base metals such as Pb, Cu, Zn, As, or Sb. Upon entering the mill, the ore all passes through the sampler to storage bins, where beds of 5000 tons each are made to insure uniformity in roasting. CLASSIFICATION OF ORES For efficiency, it has been found advisable to separate the ores into two classes according to their line content. Other constituents have their effect, such as alumina and magnesia, but, speaking generally, these are roughly proportional to the line, which, as CaO, is used as the indicator. Class A contains not more than 2 per cent. CaO and comprises about 66 per cent. of the ore treated. Class B contains over 2 per cent. CaO, and comprises 34 per cent. of the ore treated. Typical analyses of both classes are as follows: Class A Class B Insol 56.70 75.90 Al203 2.30 3.40 Fe 3.26 3.48 CaO 1.57 5.12 S 1.79 1.80 Mg0 0.21 1.08 Ignition loss 3.20 6.50 99.03 97.28 The beds of each class of ore are made as large as possible with the available ore as it comes in, to avoid changing from one bed to the other any oftener than necessary. Each roaster will handle 50 percent. more of class A ore than of class B, with practically the same results. This necessitates changing the rate of feed for each new bed and tends toward a poor roast and loss of tonnage at each change.

Jan 8, 1918

By G. Rowan, M. W. Clegg

The basic equations for the flow of gases, compressible liquids and incompressible liquids are derived and the full implications of linearising then discussed. Approximate solutions of these equations are obtained by introducing the concept of a disturbed zone around the well, which expands outwards into the reservoir as fluid is produced. Many important and well-established results are deduced in terms of simple functions rather than the infinite series, or numerical solutions normally associated with these problems. The wide range of application of this approach to transient radial flow problems is illustrated with many examples including: gravity drainage of depletion-type reservoirs; multiple well systems; well interference. INTRODUCTION A large number of problems concerning the flow of fluids in oil reservoirs have been solved by both analytical and numerical methods but in almost all cases these solutions have some disadvantages — the analytical ones usually involve rather complex functions (infinite series or infinite integrals) which are difficult to handle, and the numerical ones tend to mask the physical principles underlying the problem. It would seem appropriate, therefore, to try to find approximate analytical solutions to these problems without introducing any further appreciable errors, so that the physical nature of the problem is retained and solutions of comparable accuracy are obtained. One class of problems will be considered in this paper, namely, transient radial flow problems, and it will be shown that approximate analytical solutions of the equations governing radial flow can be obtained, and that these solutions yield comparable results to those calculated numerically and those obtained from "exact" solutions. It will also be shown that the restrictions imposed upon the dependent variable (pressure) are just those which have to be assumed in deriving the usual diffusion-type equations. The method was originally suggested by Guseinov,1 who (a) postulated a disturbed zone in the reservoir, the radius of which increases with time, and (b) replaced the time derivatives in the basic differential equation by its mean value in the disturbed zone. In this paper it is proposed to review the basic theory leading to the equations governing the flow of homogeneous fluids in porous media and to consider the full implications of the approximation introduced in linearising them. The Guseinov-type approximation will then be applied to these equations and the solutions for the flow of compressible and incompressible fluids, and gases in bounded and infinite reservoirs obtained. As an example of the application of this type of approximation, solutions to such problems as production from stratified reservoirs, radial permeability discontinuities; multiple-well systems, and well interference will be given. These solutions agree with many other published results, and in some cases they may be extended to more complex problems without the computational difficulties experienced by other authors. THEORY In order to review the basic theory from a fairly general standpoint it is proposed to limit the idealising assumptions to the minimum necessary for analytical convenience. The assumptions to be made are the following: 1. That the flow is irrotational. 2. That the formation is of constant thickness. 3. Darcy's Law is valid. 4. The formation is saturated with a single homogeneous fluid.

By M. E. Kukura, L. G. Stevens

As described in a previous presentation and in various patents, the Minerals Sciences Div. of UOP, Inc., has developed a modified reduction roast ammonia leach process for nickel laterites. This process gave considerable improvement in extraction over the conventional Caron approach as practiced in Cuba, Australia, and the Philippines. This greatly improved response was obtained with a wide variety of ores. This paper describes the pilot plant flowsheet and reviews the design features unique to the UOP process. Operating results from pilot plant campaigns are compared with bench scale results. Operating problems and their solutions are also discussed.

Jan 1, 1976

By V. Rajaram, I. P. Nielsen, H. D. Raymond

The Parachute Creek member of the Green River formation in the Piceance Basin, Colorado, contains vast reserves of oil shale, nahcolite, dawsonite, and other accessory minerals. The dry alkali process of sulfur dioxide removal using nahcolite (naturally occurring sodium bicarbonate) has great potential A room and pillar mining scheme has been designed to extract a nahcolite zone occurring at a depth of 472 m, from the lease application area of the Yankee Gulch joint venture. Geotechnical parameters affecting mine design will be discussed. A preliminary development plan for mining at the rate of 1000 t/d will be described in detail.

Jan 1, 1980

By V. Rajaram, I. P. Nielsen, H. D. Raymond

The Parachute Creek member of the Green River formation in the Piceance Basin, Colorado, contains vast reserves of oil shale, nahcolite, dawsonite, and other accessory minerals. The dry alkali process of sulfur dioxide removal using nahcolite (naturally occurring sodium bicarbonate) has great potential. A room and pillar mining scheme has been designed to extract a nahcolite zone occurring at a depth of 472 m, from the lease application area of the Yankee Gulch joint venture. Geotechnical parameters affecting mine design will be discussed. A preliminary development plan for mining at the rate of 1000 t/d will be described in detail.

Jan 12, 1979

By Thiann R. Yu, William J. Quesnel

At Kidd Creek, the annual production of 4.5 million tonnes of ore has been achieved primarily with sublevel blasthole stoping. This mining method has allowed underground operations to meet the designed production capacity while maintaining an outstanding safety record. To achieve this goal, rock mechanics principles have been integrated into each facet of mining in the planning stage, in the production stage, and in various stages of ground support. This paper evaluates the two adopted mining sequences based on ground stress patterns, blasting control, ground reinforcement, backfill support, and numerical modelling for stope stability at the mines.

Jan 1, 1984

By D. L. Archer, W. W. Owens

Conventional waterflooding often is uneconomic in highly fractured reservoirs because of the gross bypassing of the reservoir oil by injected water. Imbibition and pressure pulse flooding have been used in at least one fractured reservoir in an attempt to achieve better oil recovery performance. This paper presents the results of laboratory flow tests conducted on large cores to evaluate the possible applicability of these methods (particularly pressure pulse flooding) to different types of reservoir systems. Test data were obtained on both water-wet and oil-wet systems, and on systems having two widely different levels of compressibility and flow capacity. Results indicate that pressure pulse recoveries from fractured reservoirs will likely not exceed 5 to 10 per cent pore space with maximum response achieved during the first pulse cycle. Improved recovery by this method is possible from both oil-wet and water-wet reservoirs. Comparable saturation distributions during imbibition and pressure pulse production suggest that an initial pressure pulse cycle to speed production response would not interfere with subsequent imbibition flooding in water-wet reservoirs. INTRODUCTION There is a steady increase in the number of fluid injection projects being initiated each year to improve oil and gas recovery over that obtained by primary production mechanisms. Experience gained in different geographical areas and with different recovery methods is teaching that reservoir anatomy is one of the more important factors controlling the success or failure of such projects. Fractured formations appear to be the rule rather than the exception, especially in carbonate reservoirs. Conventional methods of fluid injection, whether it is waterflooding, gas injection or miscible flooding, have limited applicability to highly fractured reservoirs because of the severe bypassing of reservoir fluids. The result is early breakthrough of the injected fluid and rapidly increasing ratios of injected to in-place fluid with an undesirable effect on return on investment. Thus, innovations to conventional methods must be developed if recovery from fractured reservoirs is to be optimized. One new method proposed for application to highly fractured reservoirs is pressure pulse waterflooding. Although pressure pulsing with gas has been suggested' and rested in at least one reservoir; the Sohio Oil Co. is generally credited with the development and testing of pressure pulsing in conjunction with waterflooding. Publications" of Sohio's waterflood operations in the Spra-berry Trend indicate that the idea for pressure pulse flooding evolved from a critical analysis of the disappointing early performance of their flood initiated in a portion of the trend in April, 1961. This flood was planned to take advtantage of imbibiltion and high pressure gradients across the reservoir matrix blocks (unfractured Mocks of the reservoir rock which are visualized to be generally surrounded 'by the fracture system) evaluated in pilot tests by the Atlantic Richfield Co.5 and Humble Oil & Refining Co.' However, the early recovery and pressure performance of this flood indicalted that high pressure gradients induced between the fracture system and the centers of the matrix blocks were forcing water into the periphery of the blocks and temporarily interfering with the counter-current flow of oil due to imbibition. Fill-up in the blocks was occurring with re-solution of the free gas phase as pressures climbed above the original reservoir bubble point. It appeared that cessation of water injection to permit the capillary forces to become dominant and that expansion of the rock and its contained fluids during pressure reduction might aid in expulsion of oil from the rock matrix into the fractures. Subsequent production performance. aflter cessation of injection, proved this hypotheslis correct. Thus, pressure pulse waterflooding was born. Pressure pulse flooding appears to have several advan'tages over imbibition type flooding in highly fractured reservoirs. First, all wells may be used for water injection which should hasten fill-up and achieve a more rapid increase in reservoir pressure. Second, because of increased injection pressures and rates, flooding gradients will force water into the reservoir matrix more rapidly than would be achieved by imbibition alone. Third, during the pressure depletion cycle of the flood, the compressibility of the system, which has been increased by resolution of the free gas phase, provides energy for the displacement of oil at a rate greater than would correspond to countercurrent flow during imbibition. Fourth, during depletion all wells may be put on production, thus contributing to higher oil withdrawal rates on a reservoir-wide basis. One possible disadvantage of pressure pulse flooding as compared to imbibition floodling, however, is that the outer periphery of each matrix block is flooded to a residual or near residual oil saturation during the Water lnjection stage. This zone of reduced permeability to oil m'ay offer greater restriction to the production of

Jan 1, 1967

By R. B. Tippin, J. S. Browning

The feasibility of multistage heavy liquid cyclone beneficiation of spodumene was successfully demonstrated in this investigation. The indicated recovery for the multistage circuits was mathematically estimated as continuous test runs would be necessary to determine the true influence of a middlings recycle. In the three-stage circuit, both the concentrate analysis and spodumene recovery exceeded 90%. The two-stage circuits were unable to simultaneously yield an acceptable produce with a satisfactory recovery. With the Nation's growing industrial mineral requirements, the U.S. Bureau of Mines has undertaken the task of investigating new mineral dressing techniques and improving the existing concentrating methods of ore beneficiation. One such project is the gravity concentration of minerals using heavy liquid separation (HLS).1-3 Heavy liquid separation is based on the simple principle that a material, whose specific gravity is less than the density of a solution, will float on top of the liquid and a material with a greater specific gravity will sink. Heavy liquid separation techniques were developed in the laboratory over half a century ago but the process has yet to be commercially adopted. In the past, commercial operations have failed because of numerous problems.4 Industrial interest has recently been reactivated because of engineering advances. The number and quality of the heavy liquids suitable for mineral processing has increased while the cost has sharply dropped. New and improved liquid recovery systems5,6 are under consideration with present emphasis on 1) solvent extraction, 2) thermo-evaporation, and 3) water washing. The toxicity of the heavy liquids7 presents a problem, but throughout the chemical and mining industries, many similar hazardous materials are safely handled. A distinct advantage of using heavy liquids is its ability to provide a near perfect separation of fine-sized mineral particles even when the specific gravities are close. Effective separations have been made on minerals down to 200 mesh and with a density

Jan 1, 1968

By Kiyoshi Sugasawa

At Sumitomo Metal Industries, technologies for manufacturing metallurgical coke have been developed, under the names of Sumicoal System and DKS formed coke processes. Sumicoal System is the process utilizing approximately 70% conventional fine coal, 30% briquettes charge, and 2-3% caking substance. This technology was industrialized in 1975, and now the blending ratio of non-coking coal has reached up to 20%. On the other hand, a large scale demonstration plant using the DKS process was constructed and operated over one year. As the result of that test, it is thought that the DKS process has also reached the stage of industrialization. This paper will describe these new coking technologies.

Jan 1, 1977

By T. W. Atkins

ATHOUGH the magnesium industry in this country is about thirty years old, not until American industry began to amaze the rest of the world and confound our enemies with the extent and variety of our war production did the industry begin to come into its own. At the outset of the war, only three companies were producing and fabricating magnesium in this country. Today, about sixty companies are producing, casting, forging, extruding, rolling, and stamping this lightweight champion of metals. Experience in alloying, processing. and fabricating the metal gained during the war years is now being translated into hundreds of civilian peacetime applications. In no sense should magnesium be considered as a substitute for other metals. It has come into popular favor because If many unique properties in addition to is being the lightest known structural metal. These attributes are toughness, igidity, corrosion-resistance, and the ease with which it can be machined and worked. Magnesium is the third most abundant element in nature. Sea water, magnesite,

Jan 1, 1946

By S. Terry, J. G. Munro

A unique feature of the recently dedicated pelletizing complex of Hamersley Iron Pty. Ltd. is the dry grinding circuit for the iron ore fines. This facility, located at Dampier, some 800 miles north of Perth, Western Australia, has a rated annual capacity of 2 million tpy of iron ore pellets. The Mt. Tom Price orebody, which supplies the pelletizing plant, is a massive deposit of high-grade hematite containing an estimated 500 million tons of ore averaging 64% iron. The main impurities are ferruginous shales that occur in bands of varying widths in the orebody. An average analysis shows 4.4% SiO2, 2.0% A12O3, 0.05% P and 1.8% LOI.

Jan 5, 1968

By K. Hanumantha Rao, A. Nayak, . K. S. Narasimhan, S. N. Mahapatra

Selective flocculation studies carried out with iron ore tailings generated at Kudremukh iron ore plant indicate that a concentrate containing 63% iron can be obtained from the tailings containing 34% iron with around 60% recovery. This opens up the possibility of recovering most of the iron lost in the tailings generated at 2 kt/h (2200 stph) while processing 22 Mt (24 million st) ore per year. This would mean that the productivity could increase by around 50%. In these studies, it has been established that caustic degraded tapioca starch is a most effective agent for selective flocculation. While potato starch after caustic degradation can also be used, neither the parent starch nor the amylopectin compound is as effective.

Jan 1, 1986

By Harry Bapty

LONGHOLE drilling with a heavy type percussion Leyner drill, jointed steel rods, and a tungsten carbide insert bit was investigated while drilling and working a quartz barite brecciated rock. Procedure and practice were developed and its suitability for tackling pillar and sill recovery proven and extended to regular stoping at Torbrit. Torbrit, as the name implies, is a contraction of the Toric property and the Britannia Mining & Smelting Co. Ltd., the former owners. This silver property, with minor amounts of lead, zinc, and rarer sulphides of little or no economic value, was discovered in 1916 from an outcrop in the Kitsault River, 18 miles north of Alice Arm Post Office, in the Portland Canal Mining District, B. C.

Jan 11, 1954