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By Nicholas J. Grant, John Chipman

A full understanding of the behavior of sulphur in the basic open-hearth process has been delayed by lack of dependable data covering a wide range of slag conditions in the absence of other complicating factors that are likely to be present under operating conditions. It has been generally accepted that strongly basic slags will dissolve more sulphur than will those in which the acidic and basic constituents are more nearly balanced. It has been known that both slag and metal would absorb sulphur from the flame when the sulphur content of the fuel is high. It has been generally believed that manganese assists in the transfer of sulphur from metal to slag. Almost nothing has been known of the effect of temperature upon desulphurization;the data have been conflicting and there has been a tendency to depend rather heavily upon analogy with the better understood desulphurizing reaction of the blast furnace. Many attempts have been made to build up from open-hearth data a satisfactory theory of the chemical reactions involved in the process. That this has been an extremely difficult task is owing to two reasons that have been very generally recognized. The first is the parallel and simultaneous reaction of sulphur transfer between flame and bath. The second is the difficulty of distinguishing between the factors that ultimately limit the transfer from metal to slag—i.e., equilibrium conditions—and those whose influence is only upon the rate of transfer. It has been the object of the work here recounted to study the equilibrium distribution of sulphur between slag and metal in the absence of these complicating factors, with the hope that a better understanding of the equilibria involved would lead to a better control of the over-all process in the open-hearth furnace. A review of the literature on steelmaking reveals almost complete agreement with respect to the paramount importance of lime in promoting desulphurization. In expressing this effect in quantitative terms, however, and in formulating the relationships between the concentrations of other slag components and the desulphurizing power, there is little agreement. For instance, the "basicity" or basic strength of the slag is commonly measured by some kind of ratio of concentration of basic to acidic oxides. Of these, the following have been reviewed by Schenck:20 V radio = % CaO/%SiO, Körber and Oelsen's _ % CaO'. 100/% CaO + % SiO2 where (%CaO') = % CaO- 1.18% P2O5. Herty's B ratio = % CaO - (0.93 . % SO2) - (1.18% P205) Among others there appear the following: 20 References are at the end of the paper.

Jan 1, 1947

By W. M. Hirthe, E. H. Greener, D. R. McCann

It has been proposed1'2 that, at low temperatures, point defects are a strengthening factor in inter-metallic compounds whereas, at high temperatures, the deformation is diffusion-controlled and, therefore, an increase in the concentration of point defects tends to soften or increase the plasticity of a compound. More recent investigations, including those of Bloem and Kroger' on PbS, Kramers and smith4 on TiO, and Nadeau5 on LiF, have extended this concept to ionic crystals. Rutile (TiO2) is a tetragonal transition metal oxide which has a defect structure over at least the compositional range. The defect in near-stoichiometric rutile is either an oxygen ion vacancys or a titanium ion interstitial.' This investigation does not contribute to resolving the defect question but either defect would satisfy the results obtained. Six specimens having the same orientation, see Fig., 1, utilized in an independent investigation1' were cut with a diamond saw from a single-crystal boule purchased from the Linde Co. Three specimens were annealed in air at 1200°C for 4 hr and slowly cooled to room temperature in a period of 12 hr. The remaining specimens were reduced in a vacuum of l0 mm Hg at 1200°C for 4 hr and cooled at the same rate in vacuum. The reduced specimens were weighed before and after reduction and, assuming the weight loss to be oxygen, the corresponding oxygen-to-metal ratio is 1.998. All specimens were chemically polished and etched utilizing the techniques described by Hirthe, Adsit, and Brittain." The specimens were embedded in acrylic resin and mounted on a leveling vise in a Kentron micro-hardness tester. A 200-g load was applied to a Knoop indenter with a descent time of 18 sec and a dwell time of 20 sec. Eight indentations were made on a near (171) surface, approximately 3 deg from the (lii) plane, for each orientation of the major axis of the indenter relative to the crystal structure. The dependence of microhardness on orienta-

Jan 1, 1963

By E. H. Fahmy, L. C. Uren

During recent years, oil producers have observed with interest the practical success which has attended the application of water as a medium for displacement of oil from its reservoir sands in the Bradford field of northern Pennsylvania and southern New York. Here, according to various authorities, additional recoveries of frorn 2,000 to 12,000 bhl. of oil per acre have heen secured by this method, after ordinary flowing and pumping. rnethods of production had practically reached the lower limit of economic operation. Notwithstanding the success which has attended the practical use of the flooding process in the Bradford field, oil producers in other regions are skeptical of its value when applied under physical conditions differing markedly from those which characterizc the Bradford field. Its usc would probably he construed as illegal in most of the oil-producing states. This general relnctance on the part of oil producers in other regions to accept the flooding process is due in large part to lack of infor-n~ation regarding the factors that influence its operation and efficiency. With the purpose of clarifying to some extent the issues involved, and of determining when the flooding proccess may or may not beeffee-tivcly ernployed, the writers have conducted a serics of laboratory exper-imentments under carefully controlled conditions, designed to indicate, the influence of various physical, chemical arid lithologic factors. These experments have not been conducted under conditions identical with those which exist at depths far below the earth's surface, so that direct quantitative comparisons with field results are not justified, hut it is believed that the experimental results at least warrant qualitative inter-pretations that may he applied to field conditions. The methods employed in the conduct of these experiments are briefly explained, and the results, together with the conclusions based thereon, arc presented. FactoRs Influencing Displacement of Oil froM SaNdS by WAteR- flooding Before presenting the experimental data, it, will he desirable to con-sider the manner in which the residual oil is retained within the oil sand

Jan 1, 1928

By Philip E. LaMoreaux

Fluoride, generally less than 0.5 ppm, is present in ground water from rocks of Paleozoic age and older, in northern and eastern Alabama. Some of the water-bearing formations in the Coastal Plain area of the State yield water with as much as 6.8 ppm fluoride.

Jan 8, 1950

By James Johnston

Synopsis.—A description of the working of the mills of this company and the metallurgical practice in vogue, by which a remarkably complex silver ore, averaging 54 oz. of silver per ton (run-of-mine ore), is treated to give a 95.66 per cent. extraction. The main features of the processes are: The cyanide amalgamation of the high-grade ore. The cyanide treatment of the low-grade ore, after extremely fine grinding and close classification, in a caustic soda solution. The use of a wet desulphurizing process to break up refractory silver minerals. The substitution of aluminum dust for zinc dust as a precipitant. The recovery and shipment of over 13,000,000 oz. of silver in bullion at 997 to 999 fine since this metallurgy was inaugurated, about 2.5 years ago. On the completion and successful operation of the mill to treat their high-grade ore,' the Nipissing Mining Co., under the general management of R. B. Watson, started a series of investigations of the possible treatment of the low-grade ore by the cyanide process, so that they would be in a position to market only silver bullion. These tests were run in July, 1911, on a large scale, by G. H. Clevenger, on an average mixture of Nipissing ore. The results obtained by a partiai amalgamation followed by cyanide treatment gave an extraction varying from 90 to 93 per cent. and were sufficiently encouraging to warrant Charles Butters, the company's Consulting Metallurgist, in recommending that the new low-grade ore mill under contemplation should be a cyanide mill, instead of a concentrator. The cost of such a mill, capable of treating 200 tons per day, to obtain a 90 per cent. extraction at a working cost of $3 per ton of ore treated, was estimated at $250,000. In coming to a decision as to which type of mill should be erected, the concentrator, with the subsequent shipping of concentrates to a smeltery,

Jan 1, 1915

By H. O. Jahns

This paper describes the application of regression analysis for obtaining a two-dimensional areal description of heterogeneous reservoirs from short-term pressure-time data such as that obtained in interference tests. The method replaces the time-consuming trial-and-error procedure commonly used to match field data on an electric analyzer or digital computer with a systematic search which is programmed for a computer. The computer program adjusts the properties of a reservoir model automatically until a least-squares fit is obtained between observed and calculated pressure data. The reservoir is simulated by a single-phase, compressible, two-dimensional model. It is divided into a number of homogeneous blocks whose transmissibility (kh/F) and storage (Fch) values are varied to obtain the least-squares fit. The reliability of these values is determined from their standard deviations and correlation coefficients. Although the method is rigorously applicable to single-phase flow only, multiphase flow can be handled provided saturation changes are small during the test. Possibly the method can also be used to obtain a reservoir description from pressure-production history, but this application is outside the scope of this work. The paper includes, in addition to a description of the numerical procedure, a discussion of some of the problems associated with the method. Rules are given to help in selecting the number of homogeneous blocks and deciding upon their arrangement. The uniqueness of a reservoir description is considered. Finally, the use of the method is illustrated by the interpretation of field data from two interference tests. INTRODUCTION Pressure data from short-term transient tests, such as single-well and interference tests, are widely used to obtain reservoir properties. These tests are usually analyzed by assuming a simple reservoir model; very often, a homogeneous one is used. As a result, analysis of the transient data from each well frequently gives different values for reservoir properties. The problem then arises to combine all these differing results into a more detailed picture of the reservoir. One technique is to simulate the reservoir with a digital computer or with an electrical analyzer and to adjust the reservoir parameters by trial and error until the simulated pressure data are in reasonable agreement with the observed pressure data for all wells. Although this method has been used for both transient tests and pressure-history data, it is time-consuming and subjective. A second technique uses regression analysis to replace the trial-and-error procedure with a systematic search that can be programmed for a digital computer. Use of regression analysis in reservoir description was proposed recently by Jacquard and Jain.1 They divided the reservoir into a number of homogeneous blocks whose properties are varied until a least-squares fit is obtained between observed and calculated pressures. However, they did not consider their technique to be operational, mainly because of ".. .(I) the lack of experience in using the method .. . notably for the improvement of convergence; and (2) limitations imposed by the insufficiency of available computers". 1 While the analysis presented in this paper applies the same general principle used by Jacquard and Jain, the specific method is significantly different. Some differences are (1) the regression problem is solved in a different way which requires less computer time in most cases; (2) a stepwise solution, in which the detail in the reservoir description is increased from step to step, is used to improve convergence; and (3) the reliability of the estimated reservoir .properties.. as measured by their standard deviation and correlation coefficient, is estimated'

Jan 1, 1967

By A. E. Wheeler, H. Y. Eagle

The copper industry in the Province of Katanga, in the Belgian Congo, which is now controlled and operated by the Union Minére du Haut Katanga, had its inception many years ago in the vision of a Scotsman, Robert Williams, now Sir Robert Williams, Baronet. He it was who personally negotiated the mineral concession with King Leopold of Belgium, sent in the prospecting parties who located most of the present mines of the company, later arranged for the Belgian participation from which the present company was formed, and has been its active mentor ever since. The idea back of his efforts was the establishment of an industry on the Congo-Zambezi divide, of sufficient importance to draw up to it the head of the Cape to Cairo Railroad, the dream of Sir Cecil Rhodes, and the consummation of which he had left as a legacy to Mr. Williams, his successor. The reports of the prospecting expeditions showed that copper in profitable quantity was there, but many difficulties lay in the way of the establishment of the infant industry. The isolated location of the mines, various tribal wars, the Boer War, and many other factors contributed to making progress very slow. However, in spite of these difficulties the railroad was finally built and a blast-furnace plant erected at Lubumbashi, near Elisabethville, the capital of the Province. Operations of this plant were started in 1911, treating high-grade oxidized ores and producing pig copper by a reducing smelting. Production has been continuous since that time and the company has grown so that at present it ranks as the largest individual copper producer in the industry. It is a fitting monument to the foresight, optimism and driving force of its founder, and the progressive policies of his Belgian colleagues. In January, 1914, the Union Miniere du Haut Katanga engaged as its consulting engineer, Archer E. Wheeler, metallurgical engineer, at that time general superintendent of the Great Falls plant of the Anaconda Copper Mining Co. Mr. Wheeler was commissioned by the Board of Directors to proceed into Katanga, and make all necessary investigations to enable him to report on a comprehensive development program, and to recommend a scheme of treatment particularly for their low grade

Jan 1, 1934

By Frank F. Aplan

In looking into the crystal-ball scene of minerals beneficiation for 1970 and beyond, an impartial observer becomes con- fused as to what has been done and what is possible in the way of improvements. The mining official must balance the burden which is being shouldered by the mineral industry for maintaining our environment in its pristine state on one hand, with the solid advancements made in technology and cost savings on the other hand. Then the official wonders if this is really the criterion for judging overall performance today. As a prospective engineer, Dave Bolles sees it this way: "Specialization has caused many engineers to subordinate everything to doing their job the cheapest and fastest way. In the future this won't be enough. The engineer in the mineral industry will be responsible not only for mining, concentrating and smelting, but also for the resultant wastes- the mine dumps, the tailing dams and the slag piles." (See Drift on page 63).

Jan 1, 1971

By G. H. Clevenger

THE reagents now used in flotation consist of various acids or salts, which may be either electrolytes or non-electrolytes, dissolved in water and some substance or combination of substances which function as collecting or frothing agents. At times the only dissolved salts present are those naturally occurring in the water used. The general effect of the electrolyte is to greatly sharpen the separation between the gangue and the concentrate. Examples of this are: The use of sulphuric acid with zinc ores; and of sodium carbonate or calcium oxide (line) with silver-gold ores. Crude pyroligneous acid is also sometimes used when available. Various oxidizing agents, such as permanganates, bichromates, etc., are added in the selective flotation of lead-zinc ores. Many other reagents for performing certain specific functions, either real or imaginary, have been proposed, and a number of them have been tried upon a working scale. The wild orgy of experimentation which is now going on in flotation exceeds even that which followed the introduction of the Washoe process for the treatment of Comstock ores, when, among other things, sage-brush tea and tobacco juice were reagents added to the pans. Out of all this will, of course, eventually come a more or less standard practice for the treatment of each class of ore. Omitting a discussion of the functions of frothing and collecting agents, the reagents used in flotation for this purpose may be classified under five general heads: (1) Essential oils; (2) fixed or fatty oils;. (3) alcohols and their combinations with organic acids; (4) coal tar and its refined products; (5) petroleum and its refined products. A flotative agent of some kind is required in flotation as now practiced. A single reagent, as, for example, certain. of the essential oils, may perform the dual function of frothing and collecting agent, or a mixture of substances may be required.

Jan 9, 1916

By B. A. Cheadle, C. E. Ells

The ovienlalion of hexagonal a-zirconium crystals in cold-drawn Zircaloy-2 tubes and in both as-extruded and heat-treated Zr-2.5 wt pcl ND tubes has been rrleasured using the inverse Pole - figure technique. Uniaxial tensile tests hare shown the Zil-caloy-2 lubes to hare highly anisotropic delovmation behavior whereas heat-treated Zr-2.5 wt pet Nb tubes are nearly isotropic. The differences in deformation behavior are esbloilred from the observed textures of the tubes and the deformation systems known to oberate in Zircnloy,-3. Tlze vcsults lead to an explanation of the high effective strain observed fov the Zircaloy-2 tubes as colrzpared to heat-treated Zr-2.5 wt pet Nb tubes in restrained end burst tests at 280° to 300°C. THE Zr-2.5 wt pct Nb alloy. when heat-treated by quenching from temperatures slightly below the (a + p)/P phase boundary and subsequently aged at 500°C, has tensile strengths about 50 pct greater than those of 20 pct cold-worked Zircaloy-2.1 There is. therefore, considerable economic incentive to replace Zircaloy-2 with the heat-treated alloy in some in-reactor applications. notably for pressure tubes, where strength is a prime consideration. However, when tubes of Zr-2.5 wt pct Nb fabricated by extrusion and drawing prior to heat treatment were subjected to restrained end-burst tests at 300 °C. the circumferential expansion at failure1 was only 10 pct that of cold-drawn Zircaloy-2 tubes in similar tests,2 Table I. This result was not predicted from uniaxial tensile tests in which the ductilities of the two materials were quite similar.' The detailed requirement for ductility in pressure vessels has not yet been worked out. and comparison of the relative merits of cold-worked Zircaloy-2 and heat-treated Zr-2.5 wt pct Nb is further complicated by the irradiation-induced loss of ductility and hydrogen pickup each will undergo from reactor operation.1,2 Nevertheless. the lower circumferential expansion of the Zr-2.5 wt pct Nb tubes raised serious doubts on the advisability of their use as pressure vessels. For this reason, an investigation to determine the cause for different ductilities of the two types of tubes was initiated. From a study of uniaxial tensile properties and crystallographic orientation it has been found that the fracture ductilities observed in the burst tests can be related directly to the crystallographic ori-

Jan 1, 1965

By B. W. Gandrud

WET-PROCESS coal-washing tables as we know them today have been in use in this country for approximately 25 years. The literature records only a few table installations worthy of note prior to adoption of the present-day differential-motion table. According to Phillips,' six Campbell bumping tables were being operated by the St. Bernard Coal Co., Earlington, Ky., in 1893. As late as 1923, according to Richardson, 72 such tables were in operation in the Rosedale washery of the Cambria Steel Co., at Johnstown, Pa. Bumping tables probably were not used to any considerable extent except in the plant at Earlington, and at two or three plants in Pennsylvania, but they may be considered as forerunners of the present-day coal-washing table. The transition from bumping tables to the type of tables now in use signalized a revolutionary change iii table design. The advantages of the new design over the old were so outstanding as to make its adoption inevitable. BUMPING TABLES Bumping tables, as the name implies, utilized a bumping action for conveying the refuse and discharging it over the refuse end. The tables were hung from rods attached to overhead supporting beams. A shaft and cam arrangement at one end of the table served as ,the actuating mechanism and imparted to the table an endwise, back-and-forth, swinging motion. A bumping block was fixed in the proper position at the shaft end, so that the table would strike against it at the end of each backward swing. The hanger rods or stirrups were so adjusted as to give the table a slight uphill slope toward the refuse end; that is, the end next to the driving mechanism. The feed box was near the upper end of the table and designed to spread the mixture of coal and water over the width of the table. Wash water was added a short distance below the feed box. With the table in motion and coal mixed with water being fed to it through the feed box, a certain amount of stratification took place, depositing heavy refuse at the bottom of the bed in contact with the surface of the table. Constant bumping and a certain amount of

Jan 1, 1943

By R. S. Wagner, W. G. Pfann

If an electric field is applied to a conducting liquid solution, changes in concentration usually occur because of differences in ionic mobilities. A variety of ways of utilizing this effect in conjunction with the freezing process are discussed in principle. For example, if a column of binary eutectic liquid is maintained a few degrees above the melting point and a field is applied, the component solid solutions will crystallize at opposite ends of the column until the liquid is consumed. An expression for the effective distribution coefficient, k, is derived for the case of a direct current Passing through a solid-liquid interface. It is shown that k can be varied It is well known that solute distributions in crystalline substances can be controlled by careful freezing from melt or solution. It is also well known that an electric field can produce substantial changes of concentration in liquid solutions by virtue of differences over a wide range, including values outside the usual range between ko (the equilibrium value) and unity. Hence, for many systems: the efficiency of zone refining can be increased; a ko of unity can be made greater or less than unity; solutes that lower or raise the fretzing point can be concentrated at the same end of the ingot by zone refining; be made equal to unity; and the tendency toward constitutional supercooling can be reduced. The methods of field-freezing are applicable to a wide range of materials including metals, semiconductors, and ionic conductors. in ionic mobility. In this paper we discuss, in principle, some methods that combine these techniques in useful way's. The methods are designated by the general term, field-freezing. Topics discussed include separation of the components of a eutectic, crystal growth, and controlling the value of the effective distribution coefficient. The methods are applicable to a broad range of materials, including alloys, semiconductors, fused salts, and other liquid electrolytes.

Jan 1, 1962

By Oscar T. Marzke

Four alloys that precipitate the alpha phase from the beta of the copper-zinc system were heat-treated in various ways to develop as many forms of the segregate as possible. It was found that the precipitate may have the form either of plates or of needles. Plates usually result when precipitation occurs at low temperatures and needles when precipitation takes place at high temperatures. The needles tend to align themselves along certain planes in the matrix and to coalesce into plnte-like structures. The two phases were found to be related so that a (111) plane and [Oil] direction of the precipitate are parallel to a 10111 plane and 11111 direction of the matrix. DISCUSSION (E. A. Anderson presiding) D. W. Smith, Pittsburgh, Pa. (Written discussion).—Tllis report by Dr. Marzke covers completely all possible heat treatinents over a considerable range of compositiol~s in which a1pha precipitates from beta brass, and may be said to complete the Inctallographic part of this problern The lining up of ncedles of segregate to form plates, espeeially as shown in Fig. 5, appears to he regular, although the author's frequency plot in Fig. 11 makes it appear rather irregular. Has the author attempted anY correlation between some of the major dircetions and the oricntntaion of the parent grain as determined by X-ray analysis? Also, in Figs. 4, 5 and 6 the cross-sections of the needles appear to be straightsided and regular. Have these directions been correlated with the matrix latttice? Dr. Mnrzkr 's method of interpretation of the orientation rclationships between the alpha. and beta phases is a bit uncertain and seems to wed more explanation. If this relationship, as staited is such that :L (1111 plane and a [I 10] direction of that plane in the precipitate is parallel to a. {110} p1ane and a [111] direction of that, plane in the matrix, there mill be a maximum of 24 possible orientations of the alpha phase within a. single grain of the beta phasc. This relationship is expressed strercographical1y in Fig. 13, ill which the locations of a11 of the alpha {111} poles for the 24 orientations of alpha me given. Fig. 12 chccks fairly closely with this thcoretical plot,. with a few exeeptions which may be due to the inaceuracy inherent in the method used by the anthor in determining the orientations of the segregates. The method might have been refined somewhat had corrections been made for the displacement of the slip p1ancs upon deformation.

Jan 1, 1933

By R. D. Pehlke, W. M. Small

The effect of added alloying elements on the solubility of nitrogen in a liquid alloy of 74 wt pct Fe. 18 wt pct Cr, and 8 wt pct Ni has been studied. At 1600°C and 1 atm nitrogen pressure, aluminum, chromium, columbium, manganese, molybdenum, tantalum, and vanadium increase the solubility of nitrogen in the liquid 18 Cr-8 Ni alloy, whereas additions of cobalt, copper, nickel, silicon, tin, and tungsten decrease the solubility. Interaction parameters based on a constant ratio of iron, chromium , and nickel have been used to quantitatively define the changes in nitrogen solubility. INVESTIGATIONS on the solubility of nitrogen in liquid iron have usually treated the pure metal, and often the influence of a single added element. Pehlke and Elliott1 carried out a comprehensive study on the influence of alloying elements on nitrogen solubility in liquid iron, and compared their results with previous studies. Turnock and pehlke2 have recently reported a study on the solubility of nitrogen in multicomponent liquid iron alloys. The original interaction parameter proposed by wagner3 was successfully employed in these studies. The need for obtaining information on the gas solubility in more complex alloys is indicated by the increasingly significant role played by dissolved gases in the processing of iron-based materials. The commercial stainless steels, for example, represent an area where data on nitrogen solubilities are required as a function of composition, temperature, and gas pressure. The nitrogen solubility in liquid Fe-Cr-Ni alloys has been studied by Humbert and Elliott.4 Their investigation covered the entire ternary system, and attempted to use data from binary alloys to predict nitrogen contents in liquid ternary alloys. Langenberg,5 using a method developed by Morris and buehl,6 calculated the nitrogen solubilities in multicomponent iron alloys from data available on binary iron alloys at 1600°C. Nelson,7 using a regular-solution model, extended this prediction to include the effect of temperature. Chipman and corrigan8 and Turnock and pehlke2 also employed empirical methods to calculate nitrogen solubilities in liquid multicomponent iron alloys. In order to provide a basis for predicting nitrogen solubility in liquid stainless steels, and to extend the data available for thermochemically modeling systems of this type, the following investigation was carried out. The study involved measupements of nitrogen solubility in a nondilute alloy and examination of the influence of a small addition of an alloying element on the nitrogen solubility. The study was focused on a very narrow range Of composition in the vicinity of 18 wt pct Cr-8 wt pct Ni (herein referred to as 18-8) with special emphasis on the change of.nitrogen solubility with the addition of a fourth metallic element. EXPERIMENTAL PROCEDURE A Sieverts' apparatus, described previously,1,2 was used in this investigation. The charge materials were contained in a recrystallized alumina crucible and inductively melted. Additions were dropped from a glass side-arm. All materials were hydrogen-refined and vacuum-treated to eliminate or minimize the oxygen content. The source and purity of materials is given in Table I. The initial metallic charge was heated to approximately 1000°C and held under vacuum for 30 to 45 min as a means for removing hydrogen and adsorbed gases. Argon was used as the calibrating gas to determine the "hot volume". The average hot volume of the system was approximately 50 cu cm STP and a few experimental runs were made using a reaction bulb with a hot volume of 80 cu cm. The temperature range studied was from 1550° to 1700°C and the temperature was measured optically. THEORETICAL PRINCIPLES General Discussion. Nitrogen dissolves in liquid iron alloys according to the reaction: 1/2N2(g) = N (wt pct in solution) [l] The equilibrium constant, K1, for this reaction is written as:

Jan 1, 1969

By Gloyd M. Wilkes

The eastern section of the Park City district is drained to an elevation of 6300 ft, by means of the Ontario drain tunnel owned and maintained by Park Utah Consolidated Mines Co. This elevation represents a depth of 920 ft, in Park City Consolidated Mines Company's property. When development below the 900-ft. level was commenced, sinking was attempted through an incline winze in the fissure. The intensely fractured quartzite forming the walls of the vein could not be held after water was encountered, so it was decided that further sinking should be done in a vertical winze far enough in the foot-wall to be in the more solid quartzite outside the fractured zone containing the vein. Progress was good until a depth of 200 ft. below water table was reached, where the flow of water became serious. Sinking progressed 300 ft., to the 1200-ft. level, and there approximately 750 gal. of water per minute was being pumped. The last 20 ft. of sinking cost more than $200 per foot direct charges, whereas the over-all cost for the 300 ft. was $100 per foot. This high last cost was caused by excessive lost time in pumping. Crosscutting to the vein disclosed the fact that the 1050-ft. level had been developed only after drainage had been effected from the 1200-ft. level, but that the 1200-ft. level could not be opened because of the great amount of water encountered when the fractured zone was intersected. The ground in the fractured zone is so finely crushed that it precludes any possibility of economic support when it is wet. Furthermore, mining costs were found to be prohibitive after caving of vein walls had taken place as a result of an attempt to drive drifts before complete drainage had been effected. More than 3000 gal. per minute was pumped from the 1200-ft. level and the water table remained 75 ft. above this plane even after five crosscuts were driven to the fractured zone at 50-ft. intervals along the strike of the fissure from a footwall drainage drift. It was evident, therefore, that complete drainage must be effected before the fractured zone could be opened in any future development. After extensive investigations in this connection, a well-drilling campaign was decided upon to effect drainage of the fissure in advance of sinking and level development, so that all mining operations would be carried on in dry ground. Drilling Procedure A crosscut was driven through the hanging wall of the fissure on the 1050-ft. level, which was the deepest dry level at the time, to a predetermined location from which a vertical hole should reach the fractured zone at about 400 ft. below this level. A drill station was made and a raise was driven over the location for the hole, to act in lieu of a derrick or drill tower. This raise

Jan 1, 1943

By Gloyd M. Wilkes

The eastern section of the Park City district is drained to an elevation of 6300 ft, by means of the Ontario drain tunnel owned and maintained by Park Utah Consolidated Mines Co. This elevation represents a depth of 920 ft, in Park City Consolidated Mines Company's property. When development below the 900-ft. level was commenced, sinking was attempted through an incline winze in the fissure. The intensely fractured quartzite forming the walls of the vein could not be held after water was encountered, so it was decided that further sinking should be done in a vertical winze far enough in the foot-wall to be in the more solid quartzite outside the fractured zone containing the vein. Progress was good until a depth of 200 ft. below water table was reached, where the flow of water became serious. Sinking progressed 300 ft., to the 1200-ft. level, and there approximately 750 gal. of water per minute was being pumped. The last 20 ft. of sinking cost more than $200 per foot direct charges, whereas the over-all cost for the 300 ft. was $100 per foot. This high last cost was caused by excessive lost time in pumping. Crosscutting to the vein disclosed the fact that the 1050-ft. level had been developed only after drainage had been effected from the 1200-ft. level, but that the 1200-ft. level could not be opened because of the great amount of water encountered when the fractured zone was intersected. The ground in the fractured zone is so finely crushed that it precludes any possibility of economic support when it is wet. Furthermore, mining costs were found to be prohibitive after caving of vein walls had taken place as a result of an attempt to drive drifts before complete drainage had been effected. More than 3000 gal. per minute was pumped from the 1200-ft. level and the water table remained 75 ft. above this plane even after five crosscuts were driven to the fractured zone at 50-ft. intervals along the strike of the fissure from a footwall drainage drift. It was evident, therefore, that complete drainage must be effected before the fractured zone could be opened in any future development. After extensive investigations in this connection, a well-drilling campaign was decided upon to effect drainage of the fissure in advance of sinking and level development, so that all mining operations would be carried on in dry ground. Drilling Procedure A crosscut was driven through the hanging wall of the fissure on the 1050-ft. level, which was the deepest dry level at the time, to a predetermined location from which a vertical hole should reach the fractured zone at about 400 ft. below this level. A drill station was made and a raise was driven over the location for the hole, to act in lieu of a derrick or drill tower. This raise

Jan 1, 1943

By William Kelly

THE objeet of this paper is to describe the electric equipment at the iron-ore mines of Penn Iron Mining Co., Vulcan, Mich. and of Republic Iron Co., Republic, Mich.; to give the result's of tests; and to discuss the methods in use from an operating as well as from an efficiency standpoint. Electricity was introduced at the Penn mines for pumping, hoisting, and compressing air in the spring of 1907, upon the completion of a hydro-electric plant built by that company on the Menominee river about 4 miles from the mines. This plant was described in a paper1 presented before the Lake Superior Mining Institute. A paper2 presented at a meeting of the same Institute describes some of the operating features, and the safety devices of the electric hoist at the Curry shaft were briefly described in the Proceedings of the First Co-operative Safety Congress held under the auspices of the Association of Iron and Steel Electrical Engineers at Milwaukee, Wis., Sept. 30 to Oct. 5, 1912.

Jan 2, 1914

By L. N. Brown

The use of sheet and strip metal has increascd rapidly during the last few years and manufacturers have been called upon for an ever-increasing tonnage, better drawing quality, and better surface. The automobile industry is probably the most insistent in striving for a better product and a desire to reduce costs. Confronted by these demands, the mills have directed their efforts toward the delivery of material. Their personnel has been occupied largely with the problems incident to production, as any increase forced the use of new sources of raw material with their problems. These problems, combined with those met in the daily routine, have demanded immediate attention, with the result that the standardizing of heat treatments, quality, or temper, etc., have been neglected. Considerable work in standardizing has been done by many companies, but no acceptable method has been developed. The following method, therefore, is given with the hope that some method that can be accepted by the manufacturers and users may be developed. The problem of selecting a material with such properties that the losses in processing are a minimum is interesting and difficult. A description of the properties required is likewise difficult, largely because of loose terms. Another handicap is the number of methods of testing which have not been standardized and concerning which little information is available. In the selection of drawing or forming stock, it is advisable to eliminate as many variables as possible; consequently the method of testing the material is of the utmost importance. The method should be rapid and comparatively easy of application, as it is more important that a large percentage of the stock be tested with reasonable accuracy than that

Jan 1, 1923

By L. N. Brown

The use of sheet and strip metal has increascd rapidly during the last few years and manufacturers have been called upon for an ever-increasing tonnage, better drawing quality, and better surface. The automobile industry is probably the most insistent in striving for a better product and a desire to reduce costs. Confronted by these demands, the mills have directed their efforts toward the delivery of material. Their personnel has been occupied largely with the problems incident to production, as any increase forced the use of new sources of raw material with their problems. These problems, combined with those met in the daily routine, have demanded immediate attention, with the result that the standardizing of heat treatments, quality, or temper, etc., have been neglected. Considerable work in standardizing has been done by many companies, but no acceptable method has been developed. The following method, therefore, is given with the hope that some method that can be accepted by the manufacturers and users may be developed. The problem of selecting a material with such properties that the losses in processing are a minimum is interesting and difficult. A description of the properties required is likewise difficult, largely because of loose terms. Another handicap is the number of methods of testing which have not been standardized and concerning which little information is available. In the selection of drawing or forming stock, it is advisable to eliminate as many variables as possible; consequently the method of testing the material is of the utmost importance. The method should be rapid and comparatively easy of application, as it is more important that a large percentage of the stock be tested with reasonable accuracy than that

Jan 1, 1923

By George Frederick Kunz

The manifold inconveniences resulting from the absence of a uniform standard of mass for determining the weight of precious stones have long been obvious. This lack has been keenly felt in commercial transactions, and those who have devoted time and research to the study of historic diamonds and precious stones have had frequent occasion to deplore the absence of such a standard in the past. In a paper read in Chicago in 1893, before the International Congress of Weights and Measures, held in connection with the World's Columbian Exposition, the writer suggested dividing the carat into 100 parts, and constituting a standard international carat of 200 mg.; that is, 5 diamond carats or 20 pearl grains to a French gram, making 5,000 carats or 20,000 pearl grains to a ki1ogram. He also called attention to the fact that while this would depreciate the present diamoiid carat or pearl grain only about 2.5 per cent., it would abolish the troublesome discrepancies between the various carat-weights now in use, and could be easily explained and understood everywhere.' The subject of the various diamond carats, their incongruity, and the resulting confusion as to the correct weights of historic gems when definite records of them are searched for, has been fully treated by me in an extensive study of this subject in The Book of the Pearl2 To the earnest and unremitting efforts of C. E. Guillaume, Director of the Bureau Internationale des Poids et Mesures at Sévres, is largely due the eventual success of this eminently desirable reform, which he has constantly urged both by articles on the subject and by addresses delivered in Paris before the International Committee for Weights and Measures.3 The general adoption of a uniform standard for dealings in pre-

Jan 1, 1914