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By Marshall, L. K. Oliver

The use of model studies for the development of invasion patterns for cycling is .illustrated by model studies obtained with a recently developed apparatus in the solution of actual cycling problems. Introduction Depletion of a gas reservoir by cycling under pressure maintenance may be divided into three general phases. In the first phase, injection of dry gas is used to move all possible wet gas to producing wells prior to breakthrough of appreciable quantities of dry gas into producing wells. In the second phase, injection moves additional wet gas to producing wells while moderate quantities of dry gas are being produced. The third phase consists of production without injection to deplete the commercial gas reserve which remains after the cycling operation. Thus, in the first phase, a portion of the reservoir is invaded by dry gas, and the dry gas usually displaces something less than 100 pct of the wet gas from the invaded portions of the reservoir. The second phase enlarges the invaded portion of the reservoir and, at the same time, increases recovery from that zone invaded by dry gas in the first phase of the cycling operation. The result is an early yield of a substantial quantity of the liquefiable hydrocarbons in the reservoir with a minimum of the retrograde losses which occur in some reservoirs. The overall recovery from such an operation is usually high. The summation of the paths taken by dry gas in a cycling operation can be termed an invasion pattern. The use of electrical models to predict invasion patterns has been the subject of several contributions to the literature.1-3 The results of such model studies as applied to actual cases has been discussed by Kelton4 and Miller and Lents.= Recently, an improved apparatus for conducting potentiometric model studies has been developed, as described by Lee.V he purpose of this paper is to present model studies or invasion patterns obtained with this instrument in the solution of actual cycling problems. The percentage of displacement of wet gas within the invaded portion of the reservoir in cycling, increase in recoveries of wet gas by continuing cycling after dry gas breakthrough, recoveries of wet and dry gas by production after cycling, or economic factors in cycling are beyond the scope of this paper. Discussions which follow will be limited entirely to the development of suitable invasion patterns for cycling under pressure maintenance and the use of model studies therein. Discussion OF Results In using model studies to predict invasion patterns in cycling, some factors which influence the results are the following:

Jan 1, 1948

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 B. H. Sage

IN recent years there has been an increase of interest in the flow of gases at relatively high pressures. Hydrodynamic calculation of the energy losses in the flow of gases in conduits, as well as through the porous solid materials constituting natural petroleum reservoirs, requires a knowledge of the viscosity of the fluid at the pressure and temperature involved. Although there are numerous publications concerning the absolute viscosity? of hydrocarbon gases at atmospheric pressure, there appears to be little information available relating to the effect of pressure upon the viscosity of these gases. Vogel28 determined the viscosity of methane at 32° F. and atmospheric pressure. His measurements at 32° F. were later substantiated by the measurements of Rankine and Smith17 at 63° and 212° F. Ishida12 also reported values for the viscosity of methane at atmospheric pressure. Trautz and Kurz26 measured the viscosity of propane at atmospheric pressure, from 83° to 530° F., by the use of a short capillary tube. Rap-penecker18 determined the viscosity of gaseous isopentane at elevated temperatures. Day' made an accurate investigation of the effect of pressure upon the viscosity of n-pentane and isopentane at pressures from 2 lb. per sq. in. ? to the vapor pressure at 77° F. (approximately 9.8 and 13.3 lb. per sq. in., respectively). Earhart5 reported data upon the viscosity of several natural gases measured by the long capillary-tube method. The viscosity of air, at atmospheric pressure and 73.4° F., was measured by Harrington7 by the rotating-cylinder method. Kellstrom13 has recently made an elaborate investigation of the viscosity of air at atmospheric pressure. The latter work is perhaps the most accurate investigation of the viscosity of a gas that has been made. .

Jan 1, 1937

By F. E. Poulson

The discovery of two new fields, Van, in East Texas, and Darst Creek, in the Balcones fault zone, is the outstanding development in 1929. The first six months was one of the most inactive periods in the history of East Texas. Five of the interior salt domes, which had been so eagerly sought as a result of the Humble Oil & Refining Co.'s strike on the Boggy Creek dome in 1927, were drilled with discouraging results, and the Boggy Creek field itself had fallen far short of expectations. Kelsey, a structure of considerable magnitude and extent in Upshur County, was equally disappointing; the Amerada Petroleum Corpn.'s initial test on this structure was dry. The situation improved in the latter half of the year. On Oct. 13, 1929, the Pure Oil Co. discovered the Van field. This gained for East Texas a permanent place in point of future potential production. There was a similar reaction in the Balcones fault zone. The Salt Flats (Bruner) field, the important discovery of 1928, proved its rating as a second Luling, but on account of repeated failures to extend the productive zone, wildcatting during the first half of 1929 in the Luling district was dilatory. In July, however, Darst Creek, a third fault-line field of majori mportance producing from Edwards limestone (Lower Cretaceous), was discovered. Retarded as development in this field has been by various attempts at proration, interest in the Balcones fault zone fields centered on Darst Creek as the year 1929 drew to a close. Development in East Texas Fields Discovered during 1929 Van.—The discovery well, Jarman No. 1 of the Pure Oil Co., is near the town of Van in the southeastern part of Van Zandt County, Texas. It is 55 miles northeast of the Powell field in Navarro County and 45 miles west of north from the Boggy Creek field in Cherokee and Anderson counties. Early in 1927, the Van area was submitted to seismographic exploration and outlined as a large anticline, the apex of which seemed to be

Jan 1, 1930

(Under this heading will be published notes sent to the Secretary of the Institute by members or other persons introduced by members.) Mining Engineer. Graduate of Colorado School of Mines, 1912, experienced in coal, lead manganese and limestone mining, wishes execu¬tive position. A-2146. Graduate Mining Engineer.-Discharged, reserve officer, age 32, single, 7 years' experience holding responsible executive positions, in iron, copper, and talc mining. Well recommended. A-4913. Mine Manager, Superintendent or Engineer. Age 41, graduate of Michigan College of Mines; 20 years' experience in responsible positions in connection with large operations; in iron, copper, pyrites, lead and zinc mines; successful in finding and developing orebodies, increasing production, and reducing costs. Desires a position with a future. A-4081. Mining Engineer.-Graduate from Polytechnicum, Stockholm; 14 years' practical experience in Sweden, United States, Belgium, and Spain, in iron-ore development, mining, and milling; thorough knowledge of English, French and Spanish; desires position as superintendent or assistant manager. Good references; member; now in Sweden. A-4914. Research Engineer. Now in Chile on the erection of a 50-ton mill with modern machinery for the treatment of Chilean nitrate. Desires connection from the first of next year; with firm operating in South or Central America. A-4915. Metallurgical Engineer. Junior member, age 26, single, graduate Columbia School of Mines; recently discharged as lieutenant in the heavy artillery. A-4916. General Superintendent. Technical graduate, age 35, desires position over a group of four or five mines or as assistant general superintendent for a large. company. Has had experience in superintending mines, construction work, opening new and abandoned mines, safety and effi-ciency engineering and handling organized labor. At present employed by a coal company in the middle West. A-4917.

Jan 11, 1919

EUROPE continued to be unsettled, financially, commercially and socially. October opened with Germany in a state of turmoil following the Government's cessation of passive resistance to the French and Belgians. In many places there were riots with much bloodshed. In Bavaria a military dictator-ship was set up in order to keep peace. In the meanwhile France continued in an uncom-promising position.. Great Britain, having been diplo-matically discredited, disappeared from any prominence in the international picture. Under the constraint of circumstances the policy of deflation in Great. Britain was temporarily abandoned. Perhaps no other course was open, for with declining trade and heavily reduced revenue, and no chance for cutting expenses propor-tionately, a check to deflation comes of its own accord. The effects of this should become manifest in the course of a few months and should appear in the form of an improved margin between the prices for commodities and the wage costs in producing them. About Oct. 20 an effort was made to set up the Rheinland as a separate republic. On Oct. 26 were published communications from Lord Curzon to Secre-tary Hughes and the latter's reply. In these Lord Curzon drew attention to the gravity of the situation in Europe and expressed the hope that France might listen to renewed suggestions for a general inquiry. Secretary Hughes promised American cooperation, in this, with the reservation that the question of inter-national debts should not enter into the situation. In the latter part of October there were military mutinies and disorders in Greece, which resulted in the reestablishment of martial law by order of Col. Plas-tiras, who is virtually the dictator of Greece. The incipient revolt was promptly crushed.

Jan 10, 1923

By R. A. Wood, R. I. Jaffee, H. R. Ogden, D. N. Williams

The tensile properties, creep resistance. and thermal stability of highly alloyed Ti-Al-Zr alloys were examined. On the basis of these studies, the Ti-7Al-1ZZr composition was selected for more complete evaluation. The alloy was found to be weldable and free from excessive directionality. In addition, it developed maximum properties without requiring heat treatment other than an annealing operation in the alpha field. The alloy was recommended for scale up and is presently being investigated on a production-level basis. One of the more attractive properties of titanium alloys is their ability to withstand stress at moderately high temperatures, and a considerable amount of effort has been devoted to increasing the maximum service temperature of titanium alloys. This work has suggested that the optimum alloys for high-temperature service will be single-phase a (close-packed hexagonal) alloys containing significant amounts of aluminum. However, the maximum amount of aluminum which can be alloyed with titanium is between 6 and 8 pct,l since at high-aluminum contents an embrittlement reaction occurs in the anticipated service temperature range, 800" to 1100°F. It has been shown that the embrittlement reaction involves decomposition of the high-aluminum a phase to one or more new phases.' Since this reaction does not occur at intermediate or low-aluminum contents, it was felt that intermediate Ti-A1 alloys might be strengthened by a-soluble ternary additions without inducing the embrittlement reaction. The first alloying addition considered was tin, which shows extensive solubility in a titanium and has moderate strengthening tendencies. Unfortunately, it was soon apparent that tin also promoted the embrittlement reaction, and that to obtain a stable alloy, the aluminum content had to be reduced as the tin content was increased. The second alloying addition considered was zirconium, which is similar to tin in its effects on titanium. This element did not contribute to the embrittlement reaction and, in fact, appeared to increase the maximum amount of aluminum which could be alloyed with titanium without inducing instability. This paper describes an investigation of the Ti-A1-Zr a alloy region. Alloys containing from 4 to 12 pct A1 and from 6 to 15 pct Zr were examined. The properties of these alloys are described and the bases for selecting an optimum composition is outlined. This composition, Ti-7A1-12Zr, is presently being scaled up in tonnage quantities, and is being evaluated extensively throughout the industry. In addition to presenting the basis for its selection, this paper presents a description of the properties developed in laboratory material as determined during the alloy investigation. These properties suggest that this alloy can fill an important position in applications requiring light weight, fabrica-bility, weldability, and strength to 1000oF or higher. EXPERIMENTAL PROCEDURES Titanium alloy ingots were prepared by inert electrode arc melting under an argon atmosphere. Alloying elements used were 110 Bhn titanium sponge, high-purity aluminum, and reactor-grade zirconium. Pancake-shaped ingots were prepared weighing approximately 300 g. The composition of the ingots was checked by weight measurements before and after melting. The pancake ingots were forged at 2000°F to approximately half their original thickness to give a flat plate roughly 1/2 in. thick. This plate was then rolled at 1800' to 1600°F to 0.250 in. thick. All of the alloys examined fabricated well. However, alloys containing 15 pct Zr tended to overheat due to exothermic oxidation, and scaling was excessive. As might be anticipated from its effect in decreasing the ß transus, increased zirconium appeared to improve fabricability somewhat, especially during rolling at lower temperatures. Except for a limited study of heat-treatment response, all alloys were examined in the a-annealed condition. Prior to heat treatment the a and ß tran-sus temperatures were determined by metallo-graphic examination of samples quenched after annealing at 50-deg intervals in the transformation region. These data are shown in Fig. 1. Recrystal-lization appeared to occur in about 1 hr in the range 1300º to 1500ºF. Therefore, alloys were annealed for 1 hr at 1550ºF (4 and 5 pct Al), 1600ºF (6 through 7-1/2 pct Al), or 1650°F (8 or more pct Al). This produced an equiaxed a grain structure. In most alloys, a "ghost" structure was visible after the a-annealing treatment, as shown in Fig. 2. This structure apparently resulted from the acicular

Jan 1, 1963

By C. Michael Dickinson

In support of the DNA Deep Basing Program, SRI International has been performing scale model experiments on protective structures since 1973. The SRI program includes field and laboratory tests of mini- structure models with surrounding natural or simulated geology. This paper contains a synopsis of some of the results of this research.

Jan 1, 1984

By Alfred Weiss

Approximately 850 delegates from 24 countries met in Tokyo, Japan, May 24-27, for the second MMIJ-AIME Joint Meeting in 55 years, to exchange technical knowledge and experience in the fields of exploration, mining, metallurgy and petroleum engineering. The first such meeting was held in 1917 in Kyoto, Japan. Although the Mining and Metallurgical Institute of Japan was the sponsor, the entire meeting (machinery exposition, technical program, and tours) was a joint effort of the two institutes.

Jan 7, 1972

By Arthur F. Taggart, Nathaniel Arbiter

The fact that the floatability of minerals with fatty-acid collectors changes as the pH of a pulp varies was utilized in the early days of flotation, when sulphuric acid was used with oleic acid to float sphalerite and galena. from gangues which themselves float with fatty acids in alkaline pulps. Gaudin1 showed that this difference in floatability is a regular function of the extent of the change in pH. The present paper offers an explanation of the phenomenon, and on the basis thereof sets up recommendations for control of soap-flotation operations. Experimental Parallelism between floatability of a mineral in a given environment and its contact angle in that environment is so well established,2 and the contact angle is so readily and rapidly measurable, that contact angles have been used throughout the experimental work to indicate relative floatability. Experiments comprised contact-angle measurements on a number of representative minerals and metals, and a variety of subsidiary tests designed to check and to amplify the contact-angle indications. Contact-angle measurements were made by the method described in detail by del Giudice.3 Sequence of procedure for determination of the points of Fig. I was: I. Polish specimen. Most specimens yielded zero contact angle after polishing; a few showed a slight "cling." Cling is characteristic of specimens that pit on polishing; it is due to a residue of organic contamination, originally on the particle surface, which persists in the pits. The cling did not change total contact angle after conditioning, and is not, therefore, additive in the upper part of the curves of Fig. I. It may have broadened the bases of the curves for the affected minerals slightly. 2. The specimen was next conditioned in soap solution for 5 minutes. 3. The conditioned particle was transferred, under conditions that precluded surface drying, to an aqueous solution of the pH desired and contact angle determined. 4. The particle was thereupon transferred, again without surface drying, to water. The confirmatory tests will be described at the places pertinent in the argument. Discussion of Results Gaudin and Vincent4 have shown that contact angles with heptoic acid as a collector decrease for a given specimen when the concentration of collector present falls below a certain value. A similar reduction in angle occurs with collector-conditioned particles that are visibly slime-coated, and varies roughly with the extent of coating. Since in the last case the reduction in angle is certainly due to reduction in the proportion of total conditioned mineral surface presented to the bubble, the authors believe that the same condition prevails in the first case cited, and that similar reduction in angle and floatability will occur whenever starvation quantities of collector are present, whether by design or by reason of excessive consumption.

Jan 1, 1943

By Nathaniel Arbiter, Arthur F. Taggart

The fact that the floatability of minerals with fatty-acid collectors changes as the pH of a pulp varies was utilized in the early days of flotation, when sulphuric acid was used with oleic acid to float sphalerite and galena. from gangues which themselves float with fatty acids in alkaline pulps. Gaudin1 showed that this difference in floatability is a regular function of the extent of the change in pH. The present paper offers an explanation of the phenomenon, and on the basis thereof sets up recommendations for control of soap-flotation operations. Experimental Parallelism between floatability of a mineral in a given environment and its contact angle in that environment is so well established,2 and the contact angle is so readily and rapidly measurable, that contact angles have been used throughout the experimental work to indicate relative floatability. Experiments comprised contact-angle measurements on a number of representative minerals and metals, and a variety of subsidiary tests designed to check and to amplify the contact-angle indications. Contact-angle measurements were made by the method described in detail by del Giudice.3 Sequence of procedure for determination of the points of Fig. I was: I. Polish specimen. Most specimens yielded zero contact angle after polishing; a few showed a slight "cling." Cling is characteristic of specimens that pit on polishing; it is due to a residue of organic contamination, originally on the particle surface, which persists in the pits. The cling did not change total contact angle after conditioning, and is not, therefore, additive in the upper part of the curves of Fig. I. It may have broadened the bases of the curves for the affected minerals slightly. 2. The specimen was next conditioned in soap solution for 5 minutes. 3. The conditioned particle was transferred, under conditions that precluded surface drying, to an aqueous solution of the pH desired and contact angle determined. 4. The particle was thereupon transferred, again without surface drying, to water. The confirmatory tests will be described at the places pertinent in the argument. Discussion of Results Gaudin and Vincent4 have shown that contact angles with heptoic acid as a collector decrease for a given specimen when the concentration of collector present falls below a certain value. A similar reduction in angle occurs with collector-conditioned particles that are visibly slime-coated, and varies roughly with the extent of coating. Since in the last case the reduction in angle is certainly due to reduction in the proportion of total conditioned mineral surface presented to the bubble, the authors believe that the same condition prevails in the first case cited, and that similar reduction in angle and floatability will occur whenever starvation quantities of collector are present, whether by design or by reason of excessive consumption.

Jan 1, 1943

By Pete Turcic, Wade E. Cooper

Many factors influence radon-222 influx and radon-daughter concentrations in underground uranium mines. A brief review of some of these factors is presented. Current radon-222 and radon-daughter control principles and practices for U.S. underground uranium mine atmospheres are discussed and a brief review of the applicability of other possible control methods such as rock sealants, radon-222 removal, and radon-daughter removal is given.

Jan 1, 1982

By T. W. Doe, J. Noorishad

The problem of fluid flow from a well into a horizontal fracture has been studied using a nonlinear coupled hydromechanical finite element model. Such an approach is required due to the strong nonlinearity and anisotropy of deformation and fluid flow moduli introduced by the presence of the fracture. The resulting nonuniform total stress field invalidates the application of the conventional fluid flow techniques to the problem. Stable convergent solution from the above analysis are verified by a coupled steady state algorithm.

Jan 1, 1982

By P. Barnes

The sums given in the accompanying table are those actually paid for material and labor up to about August, 1875; but, as some parts of the machinery were not wholly completed at the starting of the works in September, 1875, the statement cannot be taken as an absolutely correct note of the total cost. A complete description, with engravings of the building and machinery, was given in Engineering, April 26th, 1878, in a paper by Messrs. A. L. Holley and Lenox Smith, to which convenient reference may be made. A detailed list of the construction accounts has been given in a paper, by the present writer, in vol. vi, Transactions of the Institute. A summary is given in the table of the items in each class which enter into the total cost, and also a note of the proportion which each of these items forms of the whole. A concise view may thus he obtained of the facts embodied in the statement as a whole, even though it cannot lay claim to completeness in showing the entire or final cost. An urgent suggestion has reached the writer from a distant country that such statements of cost to be really most serviceable should give the details in days of labor, in weight of iron, and in number of brick, and to this an assent is most cordially yielded. It is true, however, that the mere labor of copying arid compiling these details to such a degree of minuteness, would be very great, and, in any event, the probable difference between the plans of an existing establishment and one projected, would be so wide as to render even so complete a statement of cost of little more real service than the approximate notes given herewith.

Jan 1, 1879

By P. Barnes

THE sums given in the accompanying table are those actually paid for material and labor up to about August, 1875; but, as some parts of the machinery were not wholly completed at the starting of the works in September, 1875, the statement cannot be taken as an absolutely correct note of the total cost. A complete description, with engravings of the building and machinery, was given in Engineering, April 26th, 1878, in a paper by Messrs. A. L. Holley and Lenox Smith, to which convenient reference may be made. A detailed list of the construction accounts has been given in a paper, by the present writer, in vol. vi, Transactions of the Institute. A summary is given in the table of the items in each class which enter into the total cost, and also a note of the proportion which each of these items forms of the whole. A concise view may thus be obtained of the facts embodied in the statement, as a whole, even though it cannot lay claim to completeness in showing the entire or final cost. An urgent suggestion has reached the writer from a distant country that such statements of cost to be really most serviceable should give the details in days of labor, in weight of iron, and in number of brick, and to this an assent is most cordially yielded. It is true, however, that the mere labor of copying and compiling these details to such a degree of minuteness, would be very great, and, in any event, the probable difference between the plans of an existing establishment and one projected, would be so wide as to render even so complete a statement of cost of little more real service than the approximate notes given herewith.

Jan 1, 1879

Jan 1, 1885

By Walter E. Heinrichs

Since World War II exploration geophysics has derived its scope from the following factors: first, the usual post-war interest in exploration to rebuild war-depleted reserves; second, the impetus supplied by the uranium prospecting boom; third, increased demand for natural resources due to the Korean War; fourth, the discovery of substantial metallic ore by geophysical means in Canada, the U. S., and other countries; and, finally, continuing discoveries of commercial oil by geophysical methods throughout the world. The past year's national business slump has severely curtailed mining exploration in general and correspondingly has brought about even greater reductions in applied geophysics in mining. Petroleum exploration, conceived and executed on a broader statistical basis than mining, has kept up its geophysical programs relatively well, although domestic work has been substantially reduced.

Jan 7, 1959

By J. J. McKetta, O. L. Culberson

A preliminary investigation was made to determine the time required to attain equilibrium within the equilibrium cell for this system. Experimental and smoothed data are presented for the solubility of ethane in water for temperatures of 100°, 160°, 220°, 280" and 340 °F at pressures to 10.000 psia. The minimum solubility phenomenon disappears at 10,000 psia within this temperature range. INTRODUCTION .is a continuation of the investigation of the behavior of hydrocarbon-water systems, the experimental data on the solubility of ethane in water have been extended to 10,000 psia. The experimental apparatus, technique, materials, and analytical methods are essentially the same as previously reported.' TIME-CONCENTRATION STUDY Prior to the initial determinations of solubility in the ethane-water system. it was desired to establish the time

Jan 1, 1950

"With a total value to date of well over $200,000,000.00 for its ore production, the Tintic mining district, which is about 100 miles southwest of Salt Lake City, ranks as one of the three main ore producing areas of Utah. In it are located the biggest silver mines of the country, silver having been the chief metal produced in the camp since its start. Tintic's silver production to date has a total value of over $ 100,000,000, approximately half of the value of the camp's ore production, the balance being roughly divided among lead, gold and copper.Discovery of the camp was made in the late sixties. Lack of transportation and ore reduction facilities delayed extensive development of the area for nearly a decade.In recent years Tintic's ore production has ranged from 350,000 to 400,000 tons annually. In 1 924 the camp produced one-eighth of the silver produced in the nation with an output of 7,729,700 ounces. Its lead production was 77,765,000 pounds and its gold production 26,285 ounces.The known mineralized area of the district is found in a broad syncline striking north and south. The west limb plunges sharply and extends for a distance on its dip of approximately one and a half miles to the trough. The east limb raises gently through a distance of about two miles to the east limit of known mineralization. This general structure is broken by local faulting throughout the district, the local structural conditions playing an important part in the ore deposition. The north end of the fold is obscured by a rhyolite flow and the south end stops against a monzonite stock."

Jan 1, 1925

By F. G. Miller, J. M. Podgursky

Laboratory and pilot plant work on tabling of 14-mesh X 0 hydrocyclone under flow are summarized. Included are: operating principles of hydrocyclones and tables; performance of these two devices, separately as well as in combination; comparison of the combination hydrocyclone-table system with other fine-coal processing systems; and application of the hydrocyclone-table system in fine-coal circuits. The data show that the table actually compensates for the shortcomings of hydrocyclone and makes a combination table-hydrocyclone system attractive, particularly in those cases where fine pyrite is one of the major contaminants.

Jan 1, 1973