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By R. E. Cech, T. D. Tiemann

It has been shown that hydrogen may be made to serve as a rapid and eflicient reducing agent for Cu, Ni, Co, and Fe sulfides if a scavenging agent for hydrogen sulfide is intimately mixed with the sulfide particles being reduced. Accelerated reduction kinetics are demonstrated for nickel sulfide. Copper, nickel, and cobalt sulfides, when treated at certain temperatures in a combined reducing agent-scavenging agent system, are converted to voluminous masses of fibrous metal product. Studies have been carried out to determine the conditions which lead, on the one hand, to irregular poly crystalline fibers and, on the other, to long single crystal filaments a few microns in diameter. A mechanism is proposed to account for the formation of single crystal filuments. The sulfide minerals of Cu, Ni, Co, and Fe are an important source of these metals yet there has been comparatively little scientific effort devoted towards understanding reduction mechanisms of these minerals. This may be, in part, due to the fact that the most convenient reducing agents for carrying out such studies, viz., hydrogen and carbon, do not react appreciably with sulfides. We have found that the reaction of hydrogen with metal sulfides can be markedly accelerated by placing a scavenging agent for hydrogen sulfide in close proximity to the metal sulfide. A brief series of experiments demonstrating relative reduction rates is reported in this paper to illustrate the effect. With the reduction process thus accelerated we have observed an unusual type of reduction behavior on some of the sulfides investigated. Under certain conditions the metallic product of the reduction reaction takes the form of filaments growing outward from the sulfide particles. The present paper deals largely with efforts to classify the various types of growth forms observed. This study has shown that filamentary growths from sulfides take a much greater variety of forms than has heretofore been reported by Ercker,1 Hardy,2 and Nabarro and Jackson3 in their reviews of metallic growths from copper and silver sulfides. THERMODYNAMIC CONSIDERATIONS The thermodynamics for hydrogen reduction of metal sulfides is quite unfavorable. For the sulfides considered here equilibrium constants typically range from 10-3 to 10-5. These low equilibrium constants impose severe kinetic limitations on reduction since hydrogen sulfide must be transported out of the system at concentrations of only a few hundred ppm. Unless extremely high gas flow rates are employed the atmosphere surrounding any sulfide particle will always be essentially in equilibrium with the sulfide. If, however, one places an efficient scavenging agent for hydrogen sulfide in close proximity to the metal sulfide particles the concentration of H2S near the metal sulfide will be held to a very low value. This would permit the reduction reaction to proceed with little or no inhibition from a buildup of reaction product gas. It is well known that calcium oxide is capable of removing hydrogen sulfide from a hydrogen gas stream of low dew point.4 If a sufficient quantity of calcium oxide is mixed with the metal sulfide particles the reaction: CaO+H2S=CaS+ H2O [l] will substitute moisture in place of hydrogen sulfide in the gas stream and this will not affect, in a direct manner, the reaction: MeS +H2=Me + H2S [2] A convenient method of considering the thermodynamics of the combined reducing agent-scavenging agent system is to consider the atmosphere when the partial pressure of hydrogen sulfide is the same over both the metal sulfide and the scavenging agent, i.e., pH2S (1) =pH2S (2). As a consequence: pH2O (1) pH2(2) =K1K2 The chemical driving force for reduction will depend inversely upon the moisture content of the gas and will be 0 when, in the system, pH2O = pH2.K1K2. Table I lists values of the equilibrium constants for reduction and H2S scavenging reactions for a number of sulfides at several temperatures. Data are taken from Rosenqvist4,5 and Kelly.6 The equilibrium constant products calculated from this data show that the limiting level of gaseous reaction product has been increased by a factor of 10' to l04 as a result of substituting a reducing agent-scavenging agent system for a simple reducing agent system. One possible side effect which must be considered is the possibility that the moisture evolved in the scavenging reaction might cause the atmosphere in the system to be sufficiently oxidizing to favor the formation of oxide rather than metal. This possibility was examined by comparing the equilibrium constant products listed in Table I with equilibrium constants for hydrogen reduction of the respective metal oxides. It was found that for copper, nickel, and cobalt the combined reduction-scavenging reactions could not develop a sufficiently high oxidizing potential in the

Jan 1, 1970

By Edmund J. Korber, Donald E. Raab, Frank A. Burns

During the early 1960s, the advent of self- advancing longwall roof supports triggered serious consideration by Bethlehem management to introduce the technique of longwall mining at one of our central Pennsylvania coal mines. Although longwall mining was initially justified as a means to cope with the severe roof conditions at our Mine 32 (Watson, B., 1971), the result of the endeavor has been a consistent and reliable level of coal production, first from Mine 32 and then later from Mine 33, over a period of fifteen years. Longwall production from the Cambria Division has been the mainstay of the low volatile coal required by Bethlehem Steel for steel production. Let us review the events that led to this accomplishment, as well as where we stand today.

Jan 1, 1981

Edward A. UehlinG, New York City (communication to the Secretary*):—Mr. Baker's paper is one that brings up a subject of great importance, and if full statistics could be collectecl of the number of furnace-linings ruined by reason of bad distribution by skip-hoists, it would be found an astonishing array. Unfortunately a universal remedy has not yet been found. The fact that Mr. Baker has apparently succeeded in overcoming the trouble at Sydney, is no guarantee that the same remedy applied at another plant, where very different or even slightly different conditions prevail, mould cure the trouble. That it requires but a slight continuous difference of penetrability in the column of the descending stock of one section, over another, to produce channeling, is clearly demonstrated by Mr. Baker's experiments, by which he reversed the channeling from front to rear instead of remedying the trouble. Every change in the physical make-up of the charge necessarily requires a specific adjustment; even supposing this feasible, the regular working of the furnace is by no means assured, because with the high pressures now customary, the tendency of the ascending gases to plow their way through in a direct course, prevails, and having once opened up a passage, they will persist and cause trouble. Homogeneous filling-, hard driving and regularity of working are incompatible. The higher the furnace, the greater the

Jan 1, 1905

Mining and Metallurgy of Lead and Zinc, AIME Vol. 121, edited by Dr. C. R. Hayward in 1936, remains a document of importance today even though 34 years have passed in the meantime. Since nothing in this world seems to be permanent, however, and progress brings new and better ways to do things, a two-volume set has just been published to bring the state of the art of 1936 up to date. This two-volume set, Mining and Concentrating of Lead and Zinc and Extractive Metallurgy of Lead and zinc, incorporates the papers to be presented during the Proceedings of the 1970 World Symposium on the Mining and Metallurgy of Lead and Zinc. The Symposium is being held October 20-24, 1970, in St. Louis, a site near to the famous Lead Belt of southeast Missouri. Some eighty papers are bound in these two volumes covering exploration, geology, mining, concentrating, roasting, smelting, electrolytic processing, residue fuming, refining, etc. All of this is laced with data on tonnages, processes, assays and efficiencies obtained, and the man-hours and equipment needed to achieve these performances.

Jan 1, 1970

By James E. Adler, Timothy C. Richmond

The Stillwater District is located in south central Montana approximately 75 miles southwest of Billings, the state's largest city. It lies along the northeast front of the Beartooth Mountains and is within the boundaries of the Custer and Galatin National Forests. The first white visitors in the district were the early trappers, who were soon followed by the prospectors. These early prospectors were drawn to the area by gold and silver discoveries at Cooke City in 1870 as well as by the large gossan formation in Verdigris Creek near the west bank of the Stillwater River and by several scattered smaller gossan exposures throughout the area. The first patented mining claims were recorded in September, 1886.

Jan 3, 1974

By Reno Sales

INTRODUCTION. THE geology of Butte possesses especial interest on account of the magnitude of the ore deposits, their extraordinary richness and persistence in depth. Since its discovery in the early 60's the district .has yielded, in round numbers, 6,000,000,000 lb. of copper, 260,000,000 oz. of silver, 1,250,000 oz. of gold, and a large but not definitely known number of pounds of zinc. This enormous metal production has been derived from an ore tonnage estimated roughly at 65,000,000 tons. At the present day, most of the important mine shafts have reached a depth of. 2,400 ft., while several are more than 3,000 ft., deep. At these-great depths rich bodies of copper ore are being exploited, showing no diminution in metal content as compared with the ores of the higher levels. The present (1913) daily rate of production is approximately 14,000 tons, of which 13,250 tons may be regarded as copper ore, although a small percentage of this is minable only because of the presence of

Jan 8, 1913

By A. Werenfels

No PETROLEUM, in commercial quantities, is found in France except the small production of the Pechelbronn field (Fig. 1) in Alsace, which produced 75,000 tons in 1923; therefore the test of the petroleum prospects of the Limagne is most interesting. Under the superintendence of M. Termier, chief engineer of the French mines, a well near Crouelle (Fig. 2) was drilled in 1921 to a depth of 856.3 m. (2808 ft.); at different depths favorable showings were encountered. The well, however, was abandoned because of drilling difficulties. A second one is now being drilled near the same place.

Jan 1, 1925

By L. Bombardieri, H. F. Mills

IRON KING mine, producing gold-silver-lead-zinc ore, is 10 miles east of Prescott, Ariz. At present the 1806 level is being developed. The echelon pattern of ore deposit continues at depth but is less pronounced, and the orebody is now more or less continuous over 2600 ft of strike length. with widths 5 ft to as high as 26 ft where overlapping of lenses occurs in one section of the mine. Better continuity of ore at depth has encouraged systematic mining and improved plant facilities to offset higher operating costs. With favorable persistence of ore at depth. the three-compartment No. 6 hoisting shaft appeared inadequate to handle increased tonnage from greater depths, and in 1952, a four-compartment steel and concrete shaft was started. This is now at a depth of 1906 ft, and shaft pockets and loading cartridges are being installed on the 1806 level. Ore from the new shaft, hoisted in 51/2 -ton Jeto bottom dump skips, is dumped into a 500-ton shaft bin, from which it is fed to a 16x30-in. gyratory crusher and conveyed 415 ft through an undersurface concrete gallery to the secondary crusher and conveying system supplying the 900-ton mill. Lead, zinc, and pyrite concentrates are floated, and the flotation tailings are cyanided after desliming. Waste from the new shaft is dumped into a 250-ton surge bin, fed from this bin to a 24-in. conveyor, and discharged into the glory hole above the block cave. The new shaft is served by a double-drum 400-hp hoist used for ore and waste; the No. 6 shaft conveys men and material To secure a cheap source of waste fill for stoping operations, a block cave area was undercut In the hanging wall near the north end of the mine above the 600 level. Waste from the block cave is drawn from any of three large drawpoints on the 600 level, and a series of hanging wall transfer raises with controls and bypasses on each level provide a fast low-cost material for fill. The block cave is worked vertically through to surface in the form of a steep-sided hole 350x250 ft and several hundred feet deep, the sides of which cave and provide fill material without any blasting. Fill is a mixture of caliche-cemented surface gravel and small particles of hanging wall schist. Level Development: An orebody 300 times as long as it is wide requires a lot of development work. Former practice consisted of driving a haulage drift about 30 ft from the ore in an andesitic footwall, a drift on the ore, and crosscuts from the haulage drift at 100-ft intervals. Crosscuts are about 90 ft long. At present, only the odd numbered levels are so developed, and on the even numbered levels only the haulage drift and crosscuts are driven. Little or no timber is used for this development. This change resulted in 20 pct reduction of development costs and 50 pet reduction of square set stoping required for removal of floor pillars. Elimination of ore drifts on alternate levels leaves

Jan 1, 1957

By R. A. Garling

INTRODUCTION Since the infancy of in situ uranium mining, a growing number of hydrometallurgical processes have been incorporated into pilot and commercial scale flowsheets. Although initial design efforts were geared toward maximizing uranium recovery and minimizing plant and wellfield flow circuit maintenance, recent emphasis has shifted to improved means of water conservation and aquifer restoration. As mining units approached depletion, evaporation ponds reached minimum freeboard, and state and federal agencies demanded proof of groundwater restoration, processes including mixed bed and conventional ion exchange, reverse osmosis and electrodialysis were adopted by the industry. These units served the additional function of reducing process bleed flows during mining in states where the deep disposal well permitting ice remains unbroken. This report concerns the use of electrodialysis as an alternative to the more conventional processes used in in situ mining. In addition to a brief history and description of the process, a comparison to reverse osmosis and operational data derived from testing an Ionics, Inc. 1.31 x 10-3 m /s (30,000 gallon/day) unit at the Teton-Nedco Leuenberger Research and Development pilot will be presented. HISTORY Commercially practicable electrodialysis was contingent upon the development of synthetic ion exchange membranes in 1940's. In 1952, Ionics Inc. demonstrated that the process was amenable to the treatment of salt and brackish water and, in 1954, made their first commercial sale. The following decade saw several major electrodialysis unit sales which were generally targeted for use on private or municipal potable water treatment. Major increases in membrane desalting unit capacities, facilitated by technological advances in the reserve osmosis industry, were noted during the 1970's. The development of polarity reversing electrodialysis equipment which reduced feed pretreatment requirements, increased water recovery rates, and simplified unit operation, kept Ionics Inc. competetive in the water treatment industry. Engineering advances which incorporated automated equipment, non-corrosive construction materials, and improved ion exchange membranes allowed the electrodialysis process to compete in industrial waste treatment among other commercial markets. PROCESS AND APPARATUS DESCRIPTION The electrodialysis process utilizes direct electrical current passed across a stack of alternating cation and anion selective membranes in order to achieve an electrochemical separation of ionized materials in an aqueous solution. The membrane stack has the appearance of a plate and frame filter press and auxilliary equipment includes solution pumps, electrically actuated valves, filters, piping and a direct current power source. The ion separation membranes are thin sheets of synthetic cation or anion selective resins. Attaching sulfonate or quaternary ammonium groups to the cross linked copolymer structure determines the ion selectivity of the membrane. The membranes are separated from each other in the stack by non-conductive spacers that house flow channels which route the flow tortuously and parallel to the membranes. Direct electrical current passing perpendicularly to the membranes and solution passages attracts cations toward the cathode and anions toward the anode (Figure 1). As the ions from the feed stream pass through the ion selective membranes, they become concentrated in the adjacent brine channel and are retained there by the combined attractive force of the electrode and the repelling force of the next membrane toward the electrode. Limiting factors on the degree of demineralization possible include chemical solubilities in the brine flow and the current density that will produce an unacceptable degree of polarization (Figure 1). Feed or brine solution treatment with complexing agents or acids has been successfully applied to prevent membrane scaling. Polarization can occur when sufficient current density is applied to dissociate water in the ion depleted region of the diluting compartments near the membrane surfaces. Significant polarization is evidenced by large electrical resistances across cell pairs and notable pH differences between diluting and concentrating streams. Limiting current densities have been increased in U.S. manufactured equipment by utilizing tortuous flow paths of relatively high linear velocities thereby promoting continous solution mixing. Energy consumption is due to separating electrolytes and solutions, oxidation and reduction reactions occurring in electrode compartments, overcoming electrical resistance, conversion from AC to DC power, solution pumping and auxiliary equipment actuation. A major improvement to the basic electrodialysis process was applied in 1970 which resulted in frequent, automatic cleaning and descaling of membrane surfaces. The process, polarity reversal, incorporates alternating the cathode and anode on a periodic basis while exchanging product and brine flow channels via electrically actuated values. The reversal reduces the potential of stack plugging with CaCO3 (calcite), CaSO4 (gypsum), and colloidal materials and, in most waters, eliminates feed pre-treatment requirements. For approximately two minutes during and following the reversal, off spec. water is flushed to waste or reintroduced to the feed supply. The usual feed treatment on polarity reversing electro-

Jan 1, 1982

By J. W. Ristori, V. R. Garfias

ONE of the most serious problems now confronting Gel- many-and one that will affect Italy even more seriously if she goes to war against England and France -is that of supplying her navy, mechanized army, and air force as well as her industrial and other needs with the necessary and related products. This problem, serious even now, will become vital should hostilities on a large scale develop.

Jan 1, 1939

By J. E. Korski

Quebec Cartier Mining Co. operates a low-grade iron ore deposit at Lac Jeannine, Que., which is located at the extreme southwestern end of the Quebec-Labrador Trough (Fig. 1). The facilities there include one of the world's largest concentrators, a hydroelectric plant of 60,000 hp, and the modern town of Gagnon. A 191-mile railway connects the mine to the seaport situated at Port Cartier on the St. Lawrence River. The harbor in Port Cartier can accommodate both lake and large ocean- going vessels and is also the site of a major grain terminal. The concentrator in Lac Jeannine is designed to produce some 8 million tpy (tons per year) of specular hematite concentrate, containing 66% Fe, from approximately 20 million tons of crude ore. An annual stripping program of 5 to 8 million cu yd of waste rock uncovers the required ore. Approximately 100,000 tons of ore and waste are removed daily on a year-round, 24-hr-per-day basis. The open pit covers an area with maximum dimensions of 8,000 x 2,600 ft (Fig. 2). Present mining plans call for an ultimate depth of approximately 1,000 ft below original ground level. The rocks in the pit area are typical of this portion of the Grenville geological province. They consist largely of marble, quartz rock, pegmatite, iron formation, and stratigraphically older gneisses. The iron-ore formation consists of medium to coarse-grained specular hematite in a quartz host rock. The formation occurs locally in a plunging, anticlinal form. The topography in the vicinity of the mine is rolling, with maximum variations in elevation of about 400 ft. The hills are thickly wooded with birch, black spruce, and some tamarack. Lakes and muskeg areas are plentiful. Precipitation and temperature records have been kept since 1959. The annual rainfall has ranged between a low of 23 in. and a high of 42 in.

Jan 1, 1969

By A. R. Troiano, W. J. Barnett

The existence of a grain size stabilization effect on martensitic type reactions as shown by Scheill in an iron-29 pct nickel alloy and by Troiano and Tokich2 in cobalt prompted a review of other martensitic reactions to determine if this stabilization effect is characteristic of all martensite type reactions. Preliminary work has shown this effect to be present both in the gamma —+ epsilon transformation in an iron-20 pct manganese alloy and the martensite transformation of SAE 4140 and 3 pct Cr-O.40 pct steels. No appreciable effect was found in an SAE 2340 steel. The M, temperature for the gamma —+ epsilon transformation was lowered from 380°F to about room temperature by varying the annealing treatment following cold work as shown in Table I. The effect of austenitic grain size on the M, of three steels is shown in Table 2. M, was deter- mined by the conventional quench-temper method of Greninger and Troiano. In a single crystal the change in external shape concomitant with the homogeneous shear mechanism of the martensite transformation can take place unhindered. In a polycrystalline specimen a restraint of these changes must occur at the grain boundaries. Therefore, the smaller the grain size the greater the shear strain energy necessary for the formation of a martensite crystal. The degree of lowering of M, due to the reduction of grain size is much greater when the change in crystal structure involves only a small energy change, such as face-centered cubic —+ close packed hexagonal (that is, CO and Fe-20 pct manganese alloy). The maximum lowering of M, observed in the steels investigated was 50°F with a change in the ASTM austenitic grain size of 1-2 to 8-9. In comparison, the crystal structure change face-centered cubic —+ body-centered tetragonal involves a considerable energy change. There is little doubt that with much finer grain sizes the increased grain boundary restraint would greatly enhance this stabilization effect. The implications of this phenomenon are multifold. Undoubtedly. under certain conditions it offers a method of stabilizing high temperature phases for room temperature

Jan 1, 1949

By M. R. Tek

General equations relating the pressure drop necessary to sustain the flow of a fluid through a porous matrix at a given rate have been developed. The results indicate that at high values of flow rate the pressure-flow behavior may not necessarily satisfy the usual Darcy equation. The mathematical analysis, carried through the micro-pore geometry and extended through the macro-reservoir scale, indicate that Darcy's law, of limited applicability to certain ranges of Reynolds numbers, can be generalized through the inclusion of some additional parameters. The "generalized Darcy equation" has also been formulated in dimen-sionless form permitting the evaluation of its predictive accuracy with regard to literature data. A comparison between predicted and experimental values indicates that the generalized Darcy equation predicts the pressure drops with good agreement over all possible ranges of Reynolds numbers. INTRODUCTION The limits and the nature of validity of Darcy's law' has been a subject of every-day interest to the industry for many years. It is well known that as the Reynolds number, characteristic of the fluid flow through porous media, becomes large, Darcy's law gradually loses its predictive accuracy and ultimately becomes completely void. For the last 20 years much has been said and written on this subject. Unfortunately little has been accomplished to bring about a satisfactory agreement, at least on the nature of the threshold of validity of Darcy.'s law. Fluid dynamists, geo-physicists, and engineers all had their individual views, explanations, interpretations and concepts on the subject. To some, a mechanistic analogy with pipe-flow proved a satisfactory explanation.' To others,' turbulence, in its random character, was incompatible with the geometric structure of consolidated porous systems. To some,4 turbulence merely represented a factor influencing the permeability measurements and again to others5,6,7 em-pirical or semi-empirical correlations proved satisfactory from an engineering viewpoint. Deviations from Darcy's law at high flow rates have been studied by systematic experiments by Fancher, Lewis, and Barnes.' In an article on the flow of gases through porous metals, Green and Duwezs conclude that the onset of turbulence within the pores appears unsatisfactory to explain deviations from Darcy's law. This view is held by many others. While the subject remained controversial for many years, the development of vast natural gas reserves throughout recent years further justified considerable interest on this problem from the standpoint of gas reservoir behavior. As large amounts of field data became available from the operation of many gas fields, it became evident that the steady-state behavior of gas wells was not, in general, in agreement or compatible with Darcy's law. This suggested a careful reconsideration of all mechanisms which may account for pressure drops in addition to viscous shear. In a series of articles9,10 . Hou-peurt indicated that deviations from Darcy's law may be explained on the basis of kinetic energy variations and jetting effects without resorting to assumptions on turbulent flow conditions. Another article by Schneebeli11 indicates that special experiments by Lindquist clearly demonstrated that the onset of turbulence does not necessarily coincide with conditions of deviation from Darcy's law. This view is also held by M. King Hubbert.12 Starting with the basic pressure-flow relations suggested by Houpeurt, the derivation, development and extension of analytical expressions to -supplement and generalize Darcy's law has been the objective of this work. MATHEMATICAL ANALYSIS Derivation of Dimensionless Pressure-drop, Flow-rate Relations In considering the flow of a fluid through a porous matrix geometrically represented by a succession of capillary passages in the shape of truncated cones,810 an approximate expression may be derived relating viscous and inertial, i.e., total pressure drop to the physical properties of the fluid, geometric properties of the rock matrix and the rate of flow: ?P/?r = µ/k V [ 1 + c(m4 - 1) p V/16n" mµ w] ..........(1) Let us formally set: c (m4 - 1) / 16n" m = a d ......(2) Such a representation is equivalent to assert that the term [c(m4 — 1)/ 16n"m], variable with various porous media and probably highly variable within a given porous medium, may be macroscopically defined as equal to a lithology factor times the aver-age grain diameter d. In view of the usual grain and pore size distribu-

Jan 1, 1958

By AIME AIME

OUR new Director from the 15th District is Robert W. Thomas; of Ray, Ariz., general manager of the Ray Mines division, Kennecott Copper Corp. In electing him to this office his fellow engineers pay tribute to his ability as an engineer and express appreciation for his service to the A.I.M.E. and its Arizona Section. ?Bob? Thomas was born April 1, 1886 at St. James Minn. received his early education in the public schools of Topeka Kans. and was graduted from Topeka High School in 1905. Already he had decided upon mining engineering as a profession. so he entered the mining school of the University of Kanas from which he was graduated with the degree of B.S. in hlining enginrering. While in college he became a Student Associate of the A.I.M.E. After graduation, lution and isolated mining camps wel-e not the most desirable places in w

Jan 1, 1944

By Henry M. Rowe

Professor Ruff's most illuminating paper' describing his extremely valuable investigation of the carbon-iron equilibrium diagram assigns definite temperatures to certain very important lines in the diagram, viz.: the eutectic temperature EB (Fig. 1) and the " near-eutectic " temperature E'B', but without indicating clearly enough the reasoning which warrants these assignments. These temperatures are of such primary importance that it is well to indicate the apparent gaps in the reasoning, in the hope that they may be filled in. In his diagram, Fig. 1, the point X and the liues B'D'lII represent the experimental results reached by Ruff and Goecke;a AB, AEB, and SE represent the liquidus, the solidus, and the solubility of the carbon in solid austenite in the absence of graphite according to Gutowsky,3 AB being also in accordance with Spiecker's data; S'E' the solubility of carbon in solid austenite in the presence of graphite according to Ruer and Iljin;5 GS the line A3 after Ooerens and Meyer; 6 and EBC the true eutectic line as inferred by Prof. Ruff from Gutowsky's data. B'D' is the carbon content found in cast-iron which had apparently saturated itself with carbon in the presence of the graphite of the enclosing graphite crucibles in which the determinations were made. From its straightiiess and its sharp inflection near 6.67 per cent. of carbon, the carbon content of

Jan 1, 1913

By H. H. Stoek, G. W. Harries

The term " Anthracite Coal-Field " is generally used to refer to a comparatively small territory lying in the eastern-central part of Pennsylvania. This territory includes about 3,300 sq. miles of area, located chiefly in five counties in which anthracite-mining is the dominant industry. Although an area of 3,300 sq. miles is embraced in the region, less than one-fifth of this area, or only 484 sq. miles, is underlain by workable coal-seams. Moreover, this prorluctive portion is not a continuous area, but consists of a number of detached basins. These are known as the Northern, containing 176 sq. miles; Eastern-Middle, containing 133 sq. miles; Southern, containing 181 sq. miles; and western-Middle,containing 194 sq. miles. From the standpoint of business and trade, the region is divided into three districts, known as (1) the Wyoming, which includes the Northern field and the small Bernice basin; (2) the Lehigh region, which includes all of the Eastern Middle field and that part of the Southern field east of Tamaqua; and (3) the Schuylkill region, which includes the WesL ern-Middle field and that part of the Southern field west of Tamaqua. The relative commercial importance of these districts at the present time is shown by the coal-shipments as given in the following table :

Jan 1, 1904

By W. J. Schuster

Safety in coal mines depends largely upon adequate training of the foreman. Although management must provide modern and safe equipment and at all times keep mines in first class condition from a safety viewpoint, final results will be determined by the quality of supervision. HANNA COAL CO., Division of Pittsburgh Consolidation Coal Co., operates three large underground mines in eastern Ohio. The section of Pittsburgh No. 8 coal seam in which these mines are located varies in thickness from 52 to 64 in. It is immediately overlain by a stratum of shaly material 12 to 15 in. thick locally known as draw slate, which is structurally very weak and which disintegrates rapidly upon exposure to atmosphere. Immediately above the draw slate as it is normally found is a band of extremely high ash material 6 to 12 in. thick known as roof coal or rooster coal, and above this is a stratum of conglomerate material varying from 4 to 10 ft in depth. Overlying the conglomerate is a relatively thick stratum of limestone, the first stable material above the Pittsburgh coal seam in eastern Ohio. With the method of full-seam mining that has been adopted, draw slate is shot down, loaded with the coal, and removed in the preparation plants. The roof coal then becomes the permanent roof. The major problem in mining the No. 8 seam in eastern Ohio is control of the roof. Since the strata above the draw slate contains no material with a structure firm enough to provide self-support, the roof begins to sag in a relatively short time after the coal and draw slate have been removed. The problem thus becomes one of getting temporary safety posts under this roof as quickly as possible to prevent a break or separation from occurring either in the roof coal or in the conglomerate above it. Haulage System The Pittsburgh No. 8 seam in eastern Ohio is relatively level, with only minor local dips. Throughout the Hanna Coal Co. mines, entries are generally 12 ft wide. Rooms are driven on a 60" angle on 30-ft centers and are 22 ft wide. No attempt is made to extract the 8-ft pillars between. The entire length of main line haulage is gunited in one mine, and a major portion in another. Two of the mines have single-track main haulage roads with passways. The third, a new mine, is double-tracked, and the roof is supported by steel crossbars, 60 lb or heavier, spaced on 4-ft centers and lagged. In recent years timbering on main line and secondary haulage roads has been accomplished by one of two methods: 1—crossbars are supported on a small section of post set in a hitch hole in the rib, or 2—or a hole is drilled in the rib about 12 in. below the roof, of sufficient depth to fasten securely a short length of 40-lb rail, the bottom of the rail facing the roof, on which a short post is set directly under the crossbar. At present the hitch-hole timbering method is favored. At two of the mines the main line haulage locomotives are 26-ton, 8-wheel units. These locomotives are of the axleless type, each wheel being individually mounted on the frame. The motorman's compartment is encircled by 3-in. armor plate for the protection of the occupants. At the third underground mine conventional 15-ton locomotives are being used. However, these locomotives have been completely rebuilt in the company's shops. Equipment has been streamlined and quarters have been provided for two people, who are protected by heavy steel plate in much the same way described above. This modernization program has been completed on all secondary haulage locomotives at the three mines, and the company is well on the way to similar equipment of the 6-ton section locomotives. The following additional features have been included in their modernization: 1—additional support for the motors to prevent their falling to the middle of the track and derailing the locomotives should a break occur in the suspension bar support; 2—installation of additional bracing to prevent brake rigging from becoming displaced and causing derailments; 3—enclosure of all electric wiring in conduit or raceway; 4—provision of an enclosed compartment for the storage of re-railers, jacks, and other equipment, so that they need not be carried on the outside of the motor; and 5—redesign of the end of the locomotive opposite the operator's compartment to prevent anyone's mounting from that direction. It is interesting to note that some

Jan 1, 1955

By G. A. Beiswenger

The application of the law of supply and demand to the sale of crude oil is generally conceded, but the motives underlying the buyer's (refiner's) demands are not always obvious to the seller (producer). In some cases this obscurity has led to the conclusion that the refiner may be unnecessarily particular when he selects one crude and rejects another. This preference, however, is very largely the reflection of the refiner's product demands and the quality of the stocks obtainable from the selected crude. The purpose of this paper is to point out critical characteristies of the major classes of refined products and to show how crudes vary in their suitability for such products. With relatively few exceptions, available processing methods and addition agents make it theoretically possible to produce any type of refined product from any crude source, although it may not be economically sound to do so. The widespread application of thermal cracking for converting higher boiling stocks into gasoline is well known. More recently cracking and refining in the presence of catalysts9 have been developed, as well as various processes for polymerizing lighter hydrocarbons into gasolines having desirable characteristics.6 For several years, selective solvents have been applied commercially to refining inferior quality kerosene, Diesel fuel and lubricating oil distillates.3 Improved methods for refining lubricating oils from crude residual4 formerly suitable only for fuel, are now in use and a number of special solvent processes are available for dewaxing lubricating oils to low pour point.5 These improved refining methods have been developed not only to meet the demand for improved product quality but also to enable the refiner to obtain quality products from crude sources that would not yield such products by the older refining methods. In many cases, the utilization of these modern refining tools necessitates an appreciable expenditure for equipment as well as added manufacturing costs, and their application therefore must be justified economically. Despite the availability of such tools, the added processing costs involved and yields obtainable may render their application entirely impractical. To illustrate this point, inspections of typical cuts from various crudes

Jan 1, 1940

By E. L. Anders

The Mile Six pool is located on the La Brea-Parinas Cullcession of International Petroleum Co., Ltd., in northwestern Peru on the west coast of South America. The reservoir pressure in this pool has been maintained within 200 psi of its initial value throughout its history, and gravity drainage has played an important role in the production behavior. It has now produced 95 per cent of its estimated ultimate recovery. It is estimated that this interesting oil pool will ultimately produce 67 per cent of the initial oil in place and that the resulting residual oil saturation may be as low as 19 per cent of the pore volume (29 per cent of the hydrocarbon pore volume). An evaluation of reservoir rock and fluid characteristics and ultimate oil recovery is presented. INTRODUCTION This study of Mile Six pool was made to evaluate its performance according to latest available information. The production performance of this pool has been discussed in various articles in the past. and the reported behavior has been used as an example for application of computation procedures for gravity drainage depletion' and as an illustration of field behavior under gravity drainage or expanding gas cap drive. There have been wide variations in reported values of initial oil in place, reservoir oil volume factor. connate-water sauration, volume of effective sand, and ultimate recovery because of the paucity of reliable basic data. These various factors have been determined as accurately as practicable with the latest available information, and this evaluation is presented herein. The production history of Mile Six is an excellent example of gravity drainage depleion with effective pressure maintenance by gar injection. GENERAL Mile Six pool was discovered by cable-tool drilling in November. 1927. when well 1996 was completed in the Parinas sand. After slow development with cable tools and sporadic production. the pool was opened to continuous pro(iuction in November. 1933. and develpment was completed with rotary rigs. Pressure maintenance was started in December, 1933. by returning gas to upstructure wells. Most of the development was 'completed by 1937, but some additional wells were drilled in the period 1939-1947. and several old wells were deepened. A total of 46 oil and gas wells and 4 dry holes were drilled on approximately 7-acre spacing. Of the producers. 21 are now flowing. 2 are pumping. 44 are gas input wells. 3 are abandoned. I is a gas well shut in. and 15 are shut in because of non-commercial production or high gas-oil ratio. The locations of all wells are shown on the map of Fig. I. Total oil production on Dec. 31. 1952, was 30,867,373 bbl: cumulative gas production was 22,023,777 Mcf; and 26,410,946 Mcf of gas had been returned to the reservoir. These figures do not include oil and gas lost ill a blowout in January. 1940. GEOLOGICAL DESCRIPTION Mile Six pool is located on the northern end of a structural spur projecting from the La Brea-Negritos uplift.' The spur is probably a reflection of a basement structure. It plunges gently to the north, i broken into a complex series of fault blocks. and contain.; the Verdun Alto. Section Sixteen. and Mile Six pools. The Parinas handstone (lower Eocene!. which is the producing formation in Mile Six. occurs at an average depth of 2,200 ft in the pool and dips north and east at from 15' to 20". The pool covers an area of approximately 350 acres. Mile Six is downfaulted about 600 ft from Section Sixteen pool to the soutb. and a major fault forms its western boundarv. The north and east boundaries are formed by the intersection of the sand top with the water-oil contact which occurs at approximately 2.440 ft subsea. An original gas-oil contact probably existed at about 1.875 ft subsea. Fig. 1 presents the latest structural interpretation of the pool. and Fig. 2 is an isopach map showing thickness of the total Parinas formation above the original water-oil contact. The heavy lints of Fig. 1 are contours on the sand top, and the fine lines are contours on the fault planes. This type of straight-line structural map was developed 1)) International's geologists to reflect structural conditions where the bedding planes dip and have no curvature. 'The La Brea-Parinas Concession is highly faulted by normal fault.. The beds are flat wherever exposed. The Parinas formation is approximately 635 ft thick. and it is etimated that 62 percent II the formation is effective sand. The original oil zone was about 565 ft thick. Fig. 211 presents an electric log showing typical Parinas sand development ill Mile Six pool. The Parinas band in Mile Six i. a well-sorted. medium- to-coal-se-grained. cross-bedded sand with minor lenses of shale and small lenses and pockets of pebble conglomerate. The sand grains are subangular to rounded and consist chiefly of quartz with feldspars. biotite hornblende, and augite as accessory minerals. Because of faulting of the Parinas- formation to the east and north of the pool. there is probably l possibility of a significant, natural water drive in Mile six. The faults within the pool. as indicated in Figs. 1 and 2. are of smaller disI,laceInent and seem to act only , partial barriers to fluid movement within the reservoir. RESERVOIR CHARACTERISTICS Core analysis data are available from five wells. The data were obtained from three wells (Nos. 3401. 3586 and 3719) at the time of their completion and from well 1996 when the original liner was sidetracked and the well was deepened ill 1946. Data from well 2779 were obtained in 1943 from old cores taken when the well was deepened in 1934. From these core analyses. the average porosity was estimated to be 22.6 per cent. and the average permeability to dry ail. was estimated to be 780 and Measured productility indices varied from 3.1 to 71.4 B/D per psi differential. Specific productivity indices varied approximately from 0.1 to 0.3 B./D per psi per ft of sand.

Jan 1, 1953

By CHRIS A. HARTNAGEL

For the second consecutive year, the production of crude petroleum in New York has fallen below the 5,000,000-bbl. Mark that had prevailed previously since 1937. In 1945, the output totaled 4,658,000 bbl., a decrease of slightly more, than one per cent from the 1944 production. This total represents 2 per cent of the stripper-well production of the United States, which in turn is I 3 per cent of the total annual yield of the nation's petroleum.

Jan 1, 1946