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By JOHN JANNEY

STABILIZATION of the adjustment of normal consumption to normal production of world commodities is quite different from reducing production until visible surpluses are consumed. The first means restoration and maintenance of prosperity, the second means merely a temporary alleviation of a condition with the prime cause remaining uncorrected. Overproduction of foodstuffs in some sections of the world while millions starve in other sections represents not so much overproduction of foodstuffs as mal-distribution of foodstuffs. The flour mills of Washington and Oregon normally ship quantities of flour to China. Now, the wheat that would make this flour goes East instead of West. Is this overproduction, or is there something wrong that calls for study, analysis and correction? Can the plan used by the ostrich of hiding its head in. the sand get us by this present world tragedy, or must the challenge to solve this problem be met, constructively? Can we not make out of this breakdown in the world's economic system an opportunity? And use it as the stimulus for remedying the basic cause of the trouble and not content ourselves with devising temporary expedients that aim at remedying this or that of the obvious conditions, in themselves not causes at all but rather the evidence of causes, or that are the symptoms of the real trouble.

Jan 1, 1931

By J. F. Myers, F. M. Lewis

C. G. McLACHLAN*-I have read this paper with considerable interest and wish to congratulate the authors on the care with which they carried out their experiments and for the detailed sizing data they have presented. 011 the other hand I do not feel that these data establish their contention that "with other factors the same, the work accomplished in a fine crushing rod mill is directly proportional to the rotating speed." My reason for making this statement is that their conclusion is based on the percentage of minus 65 mesh material produced at each of the speeds at which their tests were run. The rod mill is, however, not a fine grinding machine and therefore figures based on minus 65 mesh production are figures outside the range at which it operates to best advantage. Further, if rod mill performance is to be judged on the production of such material it should have been established that a rod mill will produce it as effectively as a ball mill. To check this last point I have gone over some of the rod and ball mill grind-ing figures for our Waite-Atnulet operation and find that the ball mill at that property produces more minus 65 mesh material per horsepower than the rod mill. Moreover, this comparison is even more favorable to the ball mill if it is limited to minus 100 mesh production. It therefore seems to me that the most satisfactory basis on which to try to com-pare the performance of the rod mill in the present case is by taking a weighted average of all the new surface produced per horsepower. W. H. Coghill3 has published data which can be applied to the sizing figures presented by the authors, and if this is done the units of new surface per horsepower produced in the Tennessee tests are as follows: Admittedly the increment of increase in new surface per horsepower shown in the foregoing figures is not great, but its trend is nevertheless definitely in favor of slower speed operation, for the conditions under which these particular tests were run. I also feel that some information regarding liner contour should have been given as I think it will be found that a mill which is equipped with liners which lift the rod load can be run at a slower speed than a mill in which the liners are comparatively smooth. J. F. MYERS and F. M. LEWIS (authors' reply)—The position taken by Mr. McLachlan is to be respected even though we are all aware of the faults of surface considerations. As he points out. the increment of increase is very small. It is so small in fact that for all practical purposes it does not conflict with the conclusions of the paper. The authors appreciate Mr. McLachlan's comprehensive study of the data.

Jan 1, 1950

By H. R. Drullard

TO obtain the best results from hammer drills, close attention must be paid to two factors in drill maintenance, which are of equal importance; one is lubrication, the other is the shank. With the exception of stoping drills, most modern rock drills require both oil and grease. The oil ports are in the lubricator, on or behind the hammer cylinder; the grease port for the lubrication of the chuck sleeve and rotating mechanism is on the chuck end. Ordinary machine oil is not adapted to rock drills; a heavier more gelatinous oil such as castor machine oil or liquid grease should be used. The lubricators should be filled once for every 12 or 14 ft. (3.5 to 4 m.) of hole drilled. Grease guns should be used to fill the port in the chuck end once a shift; a medium (No. 3) grease is well adapted to this purpose. Hard grease must not be put into the lubricators, as it will not flow through that part. Contrary to the popular belief, oiling a machine once or twice a shift does not provide sufficient lubrication; the drills should be oiled once for every 12 or 14 ft. of hole drilled. The rotating handle of a stoping drill is an oil reservoir and is provided with a port for oiling. The rotating handle is packed with wick-ing, or similar material, which causes the oil to feed slowly from the handle to the other parts of the machine. Stoping drills require oil at least twice a shift; lighter oils than castor, such as Arctic Ammonia, may be used. Drills used in shaft sinking can be oiled satisfactorily by placing a good-sized, drop, sight lubricator on the station above the sinking operations and connecting it with the air-line supplying the sinking drills. If this lubricator is properly filled and adjusted, a uniform oiling of the sinking machines will be effected without the necessity of oiling the drills individually. The grease end should be filled at the station or surface before each drilling period. The shift boss should see that the machines are greased and also that the lubricators at the station function properly. The life of the air-drill hose is somewhat shortened by this method, as oil attacks the inner tube; but as some oil is always present in the compressed air, this is not a serious objection to the method.

Jan 1, 1922

By E. J. Whittenberger

OVER the past two decades, the Cr-Ni stainless steels, popularly termed 18-8 steels, have been used in ever increasing amounts in the aircraft, automotive, chemical, transportation, and building industries.' The contribution of nickel to these steels is associated with its strong austenite forming tendencies which assure good hot and cold forming characteristics, and with its beneficial influence upon corrosion resistance, especially in oxidizing acids. The adjustment of the chromium and nickel contents has been used advantageously in controlling the rollability and the response of the mechanical properties of these steels to cold reduction. With the advent of the jet age and the government stockpiling of nickel, considerable emphasis has been placed upon the development of satisfactory low nickel or nickel-free substitute austenitic stainless steels, especially for nonmilitary applications.2 Fer-ritic 17 pct Cr (AISI Type 430) stainless steel has been effectively substituted for the austenitic grades in applications with mildly corrosive exposure. However, the limited formability and ferromagnetic behavior of this grade do not permit its satisfactory use for many applications. To achieve better formability in a nenmagnetic steel and conserve nickel, a number of low nickel substitute austenitic grades of stainless steel have been developed in recent years. In most of these steels, manganese and nitrogen have been substituted for a portion of the nickel content, for example, 17 pct Cr-4 pct Ni-6 pct Mn (AISI Type 201), 18 pct Cr-5 pct Ni-8 pct Mn (AISI Type 202), and 16 pct Cr-1 pct Ni-17 pct Mn, all of which contain approximately 0.15 pct N.1 The precipitation of ferrite when large ingots of these Cr-Ni-Mn-N steels are heated to temperatures high enough for conversion to slabs on conventional universal slabbing mills has seriously affected the hot workability of these steels. This has been especially true in the case of the 16 pct Cr-1 pct Ni-17 pct Mn (sometimes referred to as 15 pct Cr-1 pct Ni-15 pct Mn) composition." Because it is possible that little, if any, nickel will be available for nonmilitary stainless steel applications in the event of a national emergency, a need has existed for a nickel-free austenitic stainless steel containing hot and cold forming characteristics similar to 18-8 steels and corrosion resistance at least comparable to the 17 pct Cr ferritic steel. The aforementioned deleterious effect of ferrite upon the hot working characteristics of the 16 pct Cr-1 pct Ni-17 pct Mn, steel indicates the importance of establishing the austenite-austenite plus ferrite phase boundaries as the first step in the development of nickel-free or low nickel substitute steels. This paper presents the data collected in an elevated temperature constitutional study of the Cr-Ni-Mn-N system at the South Works of the United States Steel Corp. Experimental Procedure The 300 compositions used in the investigation were melted in a 26 Ib induction furnace and cast in 3 14 in. diam by 18 in tall hot-tcpped ingot mo1ds.

Jan 1, 1958

By J. D. Edwards, C. S. Taylor, A. S. Russell

Solubilities and densities are reported for alumina hydrates in NaOH solutions under the conditions of the Bayer process employed to purify alumina for aluminum production. The equilibrium constants for reactions to form A102- accurately correlate the effects of NaOH concentration on the solubilities; the temperature coefficients of the equilibria lead to heats of solution of 7.34, 4.76, and 5.24 kcal for the a trihydrate, a monohydrate, and ß trihydrate, respectively. Moderate calcination does not change the solubility of the a trihydrate but increases that of the a monohydrate. At solution temperatures above 100°C, the trihydrates transform rapidly to a monohydrate. Hydro-thermally produced a monohydrate is the stable phase above 20°C. CORNERSTONE of the aluminum industry, the Bayer process for alumina production is based on the difference in solubility of hydrated alumina in NaOH solutions between 170" and 40°C. Solubilities and densities in this system were determined thirty years ago by M. Tosterudl under the direction of J. D. Edwards and C. S. Taylor. The solubility data, which still appear more concordant than those in the literature, are employed to sort out the complex equilibria in this system. The nomenclature for the alumina hydrates is that presented in The Aluminum Industry' and more recently summarized in Alumina Properties.3 a trihydrate is the purified phase analogous to gibbsite, a monohydrate is similarly akin to boehmite, and ß trihydrate is sometimes known as bayerite. Literature Goudriaan4 reviewed the early literature on alumina in NaOH solutions and presented data on the solubility at 30°C of several forms. The gel precipitated from aluminum sulphate or chloride with ammonia and dried at 130" to 140°C had the highest solubility but was unstable, its solubility being cut to one-tenth on standing in NaOH. The solubility of the gel was decreased one-third on calcination at 300" to 400°C, while that of the gel transformed in NaOH at room temperature to a crystalline trihydrate was unchanged on calcination. The preparation produced by slow hydrolysis of sodium aluminate solution with CO, in the air gave solubilities in rough agreement with later values for a trihydrate. The solubility of this form was increased slightly by the calcination. Fricke and Jucaitis5 extended the work to 30" and 60°C with a trihydrate. They also gave solubilities for ß trihydrate (bayerite b), although the residue belonging to the left branch of the solubility curve corresponded to a trihydrate. The residues at high NaOH concentrations were mono and trisodium aluminates, the latter being 3Na2O . AL2O3 • 6H2O. Solubilities of a trihydrate at 95°C and of a monohydrate at 150" and 200 °C come from the work of Magarchak.6 a trihydrate transformed to a monohydrate above 95°C. A few measurements on the solubility at 25°C of an alumina trihydrate prepared by slow hydrolysis of NaAIO, solutions were presented by Sprauer and pearce.? Their analyses showed the monosodium aluminate to have the composition Na2O.Al2O3-2.5H2O.

Jan 1, 1956

By A. R. Elsea, C. C. McBride

HIGH-TEMPERATURE alloys, that is, alloys that are strong at high temperatures, have become increasingly important with the development of modern aircraft engines. Many alloys of this type are available. However, metallurgists do not have a clear understanding of the phases or structures which are responsible for these high-temperature properties. If these basic factors were understood, it might be possible to make better or cheaper alloys for service at high temperatures. For this reason, an investigation of the fundamental factors promoting high-temperature strength in alloys was started at Battelle Memorial Institute. This was to have included a study of the relationship between the structure and properties of cobalt-chromium base alloys of the vitallium type. It soon became clear that the structure of vitallium is quite complex and that the equilibrium diagrams which should explain these structures were unreliable. As a result, the cobalt-chromium binary diagram was determined as the first phase of this investigation1. This diagram is shown in fig. 1. During the study of the cobalt-chromium binary system, it was learned that these alloys may pick up considerable nitrogen when melted and heat treated in air. The extent to which nitrogen affects the various reactions in cobalt-chromium base alloys was not known, but there were indications that this impurity might be responsible for some of the erratic test results obtained for vitallium. Consequently, nitrogen was the first ternary addition studied. Thereafter the work was extended to ternary additions of iron and of nickel. This paper describes the investigation of the effects of nitrogen, iron, and nickel upon the reactions in cobalt-chromium alloys with 80:20 and 68:32 cobalt-chromium ratios. Experimental Work Alloy Preparation: A series of cobalt-chromium base alloys containing various amounts of the third element being studied were made for both the 80:20 and the 68:32 cobalt-chromium ratios. Electrolytic chromium, cobalt, and iron, and reagent-grade nickel powder were used as melting stock. Table I contains the chemical analyses of these materials. The charges were melted in alun-dum thimble crucibles which absorbed chromium oxide and effectively deoxidized the melts. These crucibles were supported by close-fitting graphite sleeves so that if they cracked during melting the metal would not be lost. Carbon increases, during

Jan 1, 1951

By L. O. Bacon

IN the spring of 1952 Calumet and Hecla Inc. began a geophysical program near Shullsburg, Wis., in the Wisconsin-Illinois lead-zinc district, to assist the geological and drilling exploration programs. Sphalerite, the ore mineral in this area, occurs with a considerable amount of marcasite. In general the higher the percentage of sphalerite in the ore, the higher the percentage of marcasite; however, there may be mineralized zones high in marcasite but low in sphalerite. Orebodies in general are relatively narrow and elongated. Reconnaissance exploration of virgin areas consisted of drilling along lines at 500 to 1000-ft intervals. Whenever a mineralized zone was intersected additional drilling was done to determine whether or not the zone carried zinc percentages of ore grade and, if so, to delineate the body. Calumet and Hecla Inc. was interested particularly in a method that would show the direction and position in which to drill from the original discovery hole. This suggested a method of contacting the orebody, which occurs at depths ranging from 100 to 200 ft, with one electrode. After a number of procedures had been considered it was decided to use equipotential line methods. Instrumentation and Field Procedure: The power source used was a 400-cycle Signal Corps motor-generator having a rated output of 1200 w at 115 v. The detection unit consisted of test probes, a two-stage amplifier, and &apos;head phones for determining the equipotential line by audio null. Field procedure consisted of contacting the sulfide body in the hole by a specially built spring-loaded expanding electrode which would be lowered into the hole, in the closed. position, until it reached the mineralized zone. At that point the mechanism was released so that the arms would make contact with the walls of the hole in the same manner that a well-bore caliper does. This electrode was then connected to the generator, the other terminal of which was connected to the surface electrode. The surface electrode was either a point, a straight line, or a circular line electrode. The point surface electrode was placed at a considerable distance from the hole, that is, 2500 to 5000 ft, depending somewhat upon the depth to the sulfide zone and the distance from the hole containing the subsurface electrode to which exploration was considered. A higher voltage output from the power source would have been desirable, although no difficulty was encountered in determining null points to a distance of 500 ft. Straight line electrodes used were approximately 1000 ft in length at a distance of approximately 1000 ft from the hole containing the subsurface electrode. The circular line electrode used consisted of 4400 ft of bare No. 10 copper wire, which provided a circle of 700-ft radius. All line electrodes were fastened to the ground at 20-ft intervals with copper staples 4 in. long. Equipotential points were determined at 25 to 100-ft intervals. Location of the points was made by plane table and stadia. In open country with a three-man crew, the points were plotted as they were determined. With a two-man crew, pegs were placed at equal potential points and surveyed in after several equipotential lines were determined. Although interpretation of results given in this paper is qualitative, the paper as a whole would not be complete without a discussion of the theoretical distribution of potential due to a circular line electrode. The theoretical distribution would be required if a quantitative interpretation of the measured potential distribution were to be made. The theoretical potential distribution due to a circular line electrode can be obtained by means of Legendre polynomials. Using the method as developed by Weber,&apos; the potential for a circular line electrode in a semi-infinite, homogeneous, isotropic medium can be expressed, using the spherical coordinate system, as: V(r,n) = pi/2pR[S(r/R)nPn(cos?)Pn(cosa)]r<R [1] er V(r,a) =pI/2pr[S(r/R)Pn(cos?) Pn(cosa)]r>R [2] where: 0 is the angle at the origin, taken on the axis of the circular electrode between the axis and the line drawn to the circumference of the circular electrode. a is the angle between the axis and the radius, r.

Jan 1, 1957

By C. W. Davis, R. S. Dean

AMONG naturally occurring inorganic compounds, magnetite has many unusual and interesting properties, and it is the purpose of this paper to call attention to these properties and review possible uses of magnetite that might be based on them; in other words, to see what uses may be found for magnetite as a physical rather than as a chemical entity, as a mineral rather than as an iron ore. The Mineral Physics Studies initiated in the Metallurgical Division of the U. S. Bureau of Mines a few years ago gathered together much information on mineral properties, and they are therefore the principal source of material for this paper. Magnetic Properties Of Magnetite And Possible Uses As A Magnetic Material Magnetite is unique among minerals for its great magnetic susceptibility, approximately one-third that of soft iron, and some magnetites are permanent magnets, or lodestones. The literature contains many measurements of magnetic properties of individual magnetite crystals, but no systematic survey of the effect of mechanical preparation and heat-treatment was available until the recent investigations of the Bureau of which included not only susceptibility but coercive force and remanence as well. For the purpose of orientation, Table 1 gives the magnetic properties of several samples of magnetite and of a few other substances3. This table indicates that when ordinary magnetite is powdered it decreases in susceptibility and increases in coercive force and remanence, approaching the properties of lodestone. The properties of lodestone are in fact probably due to the development of very large internal surface on fine grain size4.

Jan 1, 1937

By J. W. Downey, M. V. Nevitt

MUELLER and Knott&apos; have reported that Ti2Cu has the Si2Mo-type (Cllb) structure. The lattice parameters of Ti2Cu and the positions of the titanium and copper atoms are given by them as follows: ao = 2.944A; co = 10.786A 6 atoms per unit cell: 2 Cu (a) 000; 1/2: 1/2, 1/2 4 Ti (e) 002; 1/2, 1/2, 1/2 + z 00 -2 ; 1/2. 1/2. 1/2- z where z = 0.341 We have found eight other binary compounds which appear to be isostructural with Ti2Cu. All of them involve the combination of a titanium group element with a copper group element or a titanium group element with palladium. The compounds and their lattice parameters are given in Table I. The alloy samples were prepared by arc melting metals having a purity of 99.9 pct or better. They were homogenized for 72 hr at 900°C in evacuated capsules and quenched in tap water. Filings were prepared, and these were reannealed for 4 hr at 700°C, also in evacuated tubes. The lattice parameters were determined by a least squares Bnalysis of the back reflection lines of patterns made with cobalt radiation. It was not possible to make a precise determination of the lattice parameters of Zr2Au because the filings underwent rapid oxidation at room temperature. The evidence supporting the large tetragonal cell containing 6 atoms involves the presence of the reflections 002, 101, 004, 112, 114, 202, and other reflections with higher indices for which I = 3n. Three or more reflections corresponding to these indices, which cannot be indexed on the basis of a small body-centered tetragonal cell containing 2 atoms, are observed in the patterns of all of the compounds listed in Table I. They are strongest and most numerous when the components have large differences in their atomic scattering factors, as is the case in Ti2Pd, Zr2Cu, and Hf2Cu. The values of the z parameter should be regarded as approximate They were selected on the basis of the best agreement between the observed intensities of two pairs of closely spaced powder pattern lines (004): (112) and (114): (202) and the corresponding intensities calculated for several values of z. An ordering scheme was assumed in which titanium, zirconium, or hafnium atoms occupy the titanium positions of Ti2Cu, and copper, silver, palladium, or gold atoms occupy the copper positions. Calculated and observed intensities of the aforementioned lines and the other lines of the patterns are in satisfactory agreement, but a refinement of the z parameters and a final confirmation of the ordering arrangement must await a more detailed study. It is interesting to note that in transition metal systems at A2B stoichiometry the Si2Mo-type structure competes for stability with two other fre-

Jan 1, 1962

By J. E. Warren

To clarify the specific questions raised by J. E. Warren&apos;s discussion, the following remarks are offered. 1. It is correct that stratification is assumed in the application of the statistical zonation technique, but this does not constitute a limitation. If, in fact, the reservoir is not stratified the zonation technique will show it. The reservoir is then considered as one zone with a particular distribution of permeabilities. 2. The statistical zonation technique was intended as wells may not be an adequate measure of the lateral permeability changes; e.g., if the data presented in Table A-4 of the subject paper are evaluated on the basis of two crossed classifications with interaction, the variation between zones is significant with a probability greater than .99; however, the variation betwen wells is also significant with a probability greater than .87. It is apparent that the technique suggested by the author can be generalized to provide a powerful method for describing petroleum reservoirs. This generalization can be achieved by treating the core data as a two-way classification to determine the between-zones and the between-wells variations; then, the build-up permeabilities can be analyzed, perhaps on at least-squares basis, to establish the probable distribution of the permeabilities within the zones associated with the individual wells. an additional tool for the reservoir engineer to use together with other techniques and all available information. If pressure build-up permeabilities are available, they should certainly be included. Pressure build-up tests were not available for the reservoir considered in the paper. 3. The proposed correlation of zones between adjacent wells was the best of the techniques that I examined. It is not so much a "measure" as an indication of lateral permeability changes, regardless of whether they are seemingly random or form an obvious trend.

By J. D. Rice, H. H. Rachford, G. H. Bruce, D. W. Peaceman

The problem of unsteady-state gas flow through porous media leads to a second-order non-linear partial differential equation for which no analytical solution has been found. In this paper a stable numerical procedure is developed for solving the equation for production of gas at constant rate from linear and radial systems. An electronic digital computer is used to perform the numerical integration using an implicit form of an approximating difference equation. Solutions are presented in graphical form for various values of dimension-less parameters. The solutions are compared with the laboratory study of gas depletion in a linear system. INTRODUCTION Production of fluids from porous rock reservoirs is essentially a transient process. Transient gradients develop as soon as production begins, and further withdrawals continue to cause disturbances which propagate throughout the reservoir, each adding in some way to the prior ones. A correct mathematical analysis of this behavior is complicated by the fact that the transient or unsteady-state flow of compressible fluids must be described by difficult second-order partial differential equations. As a practical matter, three distinctly different cases arise: 1. Flow of single-phase liquid 2. Flow of gases 3. Multiphase flow The first of these has been found to give a linear second-order equation similar to the well-known heat flow equation. where 7 is fluid density, 8 is time, and a a constant for the system, provided d 7 = r cdp, where the compressibility, c, is constant over the range of pressure, p, considered. Solutions of Equation (1) for both linear and radial flow are available in several forms.2&apos;3&apos; On the other hand. the second case, which is the flow of gas, gives a non-linear second-order equation, the solution of which is not known. Although a number of approximate solutions have been proposed, each is limited in value by the associated simplifying assumptions. Inasmuch as the analysis of transient flow is limited to liquid systems, a solution of the second case is necessary if further progress is to be made in studying underground fluid movement. For this reason a solution of Equation (2) was undertaken by means of numerical integration of approximating difference equations. BASIC DIFFERENTIAL EQUATION Equation (2; is derived by combining the equation of continuity, the perfect gas law, and Darcy&apos;s law to give the basic differential equation Strictly speaking, the fluids present in a gas reservoir are not perfect gases. Furthermore, there are indications that over certain velocity ranges, Darcy&apos;s law is not applicable. It would not be practicable. however, to attempt to obtain numerical solutions which would take into account all the possible variations from these laws which could occur in actual systems. The

Jan 1, 1953

By John E. Conley

THE slate industry of the United States has shown a marked decline in value of products made annually since the peak year 1925, although there has been moderate improvement over the lean years 1932 to 1934. In 1940, the value of all slate products sold was approximately 5 ¾ million dollars for a total output of 473,450 short tons. The quantity sold was a little less and the value a great deal lower than the annual averages for the past two decades. Enormous quantities of waste materials result from the quarrying, splitting and milling of slate. Obviously, utilization of such waste material is desirable, not only from the viewpoint of economical operation but also for the purpose of conserving natural resources. One possible use is to produce expanded or puffed lightweight aggregate for use in concretes. Such concretes are strong enough for specific uses, and the advantage of lightness could be obtained in such structures as the walls and roofs of buildings, suspension-bridge roadways and various other applications where weight is a factor. Conceivably, these uses could consume an appreciable annual tonnage. USE OF WASTE SLATES FOR MAKING AGGREGATES The lightweight-aggregate industry has been discussed elsewhere4.5 and need not be covered in detail in this paper. The materials commonly utilized are naturally occurring aggregates such as volcanic cinder, tuff and pumice; by-product materials, such as ordinary cinders and air-cooled slags; and the specially manufactured products, including Haydite, Pottsco, Gravelite, Cel-seal, Superock and Waylite. Slates, however, have not been given the consideration they merit, especially in the United States. In the British Isles, some work has been done3 on certain Welsh slates by the Building Research Station to stimulate the use of these wastes. REQUIREMENTS FOR RAW MATERIALS As pointed out by Hughes,4 the light-weight-aggregate industry is segregated in regions adjacent to large cities in order to localize the market and avoid the necessity of long freight haulage. Waste slate from the deposits of eastern Pennsylvania, northern Maryland, and Virginia would meet the basic requirement of any low-priced structural raw material. One apparent advantage is attained when slate waste, normally discarded, is utilized in the manufacture of a by-product. Mining or quarrying costs usually have been assessed against the main product. Some additional grinding might be desirable, but this operation would be relatively cheap, as most slates grind easily. It is believed that virtually all slates, when properly heated, will expand to some degree. However, types that will expand from 3 to 7 times their original volume are preferred. Fig. I illustrates the expansion of a Pennsylvania slate. The cube originally

Jan 1, 1942

By William Hilliard

IN any manufacturing business, it is of vital importance that the management should know the exact cost of the units of production. Without such knowledge, a company can sell blindly in the open market, obtaining the best prices it can in competition with other firms, and manage perhaps to continue in business for a time; but at any moment, and especially in a period of falling prices, such a firm is at a loss to know exactly at what point it can sell at a profit and exactly how much it is losing per unit if it sells below that point. Furthermore, it is necessary not simply to know the exact total cost per unit, but to know definitely all the different-factors which enter into that cost. A firm manufacturing pocket knives had been doing a profitable business for many years when it began to earn smaller and smaller profits, until there was scarcely any profit at all being realized. Being unable to determine exactly what its future policy should be, it called in experts who studied the past records carefully and followed out for a period a better cost, system. Investigation then showed that on several different kinds of knives in common use, a small profit per unit was being made. On a number of special kinds of knives, of which the firm was very proud, it had been forced to cut prices under the pressure of outside competition and had believed that a small profit per unit was still being made on that product, while a detailed cost analysis showed that a loss was being incurred on each knife of that kind produced. It then became clear that the company must either give up the special line and concentrate wholly on the cheaper knives and extend their sales to territory not yet developed; or expand its plant and produce more of the higher grade knives and thus lower the cost per unit enough to make money on the higher grade knives also, if conditions warranted such expansion. Investigation revealed that the market for large quantities of the high-grade -knives was decidedly uncertain and that the most promising move would be to manufacture only the less expensive knives on a larger scale. That plan was carried out and the concern began again to make a better profit.

Jan 1, 1932

By R. W. Kewish

The preparation of massive uranium metal containing very low concentrations of a number of light elements by bomb reduction of UF4, with calcium is described. Details of procedures are given for preparing high-purity ingredients for the bomb reduction. The as-reduced uranium metal contained, on the average, less than the following amounts of light element impurities, in ppm: Li, 0.1; Be, 0.1; B, 0.1; C, 25; 0, 70; Na, 1; Mg, 3; Al, 2; and Si, 7. Other impurities for which the metal was examined averaged, in ppm: Ca, < 10; V, < 10; Cr, 2; Mn, 6; Fe, 50; Co, < 5; Ni, 8; and Cu, 1. THE preparation of very high-purity uranium metal in massive form for research purposes is of great importance. Recently the kilogram-scale preparation of uranium metal containing less than 70 ppm of detected impurities was accomplished by Blumen-thal and coworkers by vacuum remelting of high-purity crystals of uranium obtained by fused salt electrolysis.1"3 Albert and coworkers4 have reported successful experiments in lowering the concentrations of certain impurity elements in uranium, notably iron, to a few ppm by the zone-melting method. The present paper describes the preparation of high-purity massive uranium metal by the bomb reduction of UF4, with calcium. Early in 1951 a program was undertaken at the Los Alamos Scientific Laboratory to prepare uranium metal of very high purity with respect to a number of the light elements. The methods considered for this purpose were 1) bomb reduction of a uranium halide with calcium, 2) electrolysis of fused salts, and 3) hot wire decomposition of UI4, The first of these processes had been used extensively at Los Alamos since 1943 (and still is used) for the production of uranium metal.5 In considering the three processes it was evident that either of the last two would require an extensive development program with no certainty of success. On the other hand, a study of available data showed that uranium metal of very high purity with respect to some light elements had occasionally been made in routine processing by the first method. It was therefore decided that an intensive study of the bomb-reduction process would be made to see if it could be improved to yield uranium metal with very low concentrations of light elements. DEVELOPMENT OF PROCEDURES The bomb-reduction process used at Los Alamos consists of reducing UF4 with calcium, using iodine as a booster. The reaction is carried out in a magnesium-oxide crucible enclosed in a steel bomb. Argon is used in the bomb to avoid objectionable side reactions which would occur in the presence of air. All ingredients for this bomb-reduction process were examined as possible sources of light elements. It was known that high-purity UF4 was required. The calcium used in the reductions was a source of carbon and magnesium. The magnesium-oxide crucibles were sources of boron, silicon, and magnesium. The iodine did not appear to be a source of any impurities. Pure UF4- The UF4 for bomb reduction is prepared from U3O3 , by successive reduction to UO2, with hydrogen and hydrofluorination of the UO2, with anhydrous HF. Since it was known that no impurities were normally introduced during the gas-solid reactions, effort was directed toward the preparation of high-purity U3O3. Of the many possible procedures for the purification of uranium solutions the following were investigated: 1) Precipitation of uranium peroxide. (Two procedures were tried. The first consisted of simultaneously adding hydrogen-peroxide and ammonium-hydroxide solutions to a uranyl-nitrate solution, containing citric and malonic acids, at such relative rates that precipitation was carried out at a constant pH of 1.5 The second consisted of simultaneously adding uranyl-nitrate, ammonium-hydroxide, and hydrogen-peroxide solutions to an aqueous solution

Jan 1, 1960

By M. A. Roche

AST fall over half a million tons of ore and rock were broken in one blast at the open pit of the Hudson Bay Mining & Smelting Company&apos;s operation, at Flin Flon, Manitoba. The following particulars of the blast, and details of the preparatory work, indicate how an operation of this scope is carried out. The data given, in essentially the present form, were first published by The Canadian Mining Journal. The area blasted was 150 ft. wide and about 700 ft. long. A total of 123 tons of 50 per cent forcite gelatin, in 5 by 16-in. cartridges, was used for the charge. Drilling for the blast was started on May 29, and was completed late in August, requiring 1297 machine shifts for drilling only. Total footage drilled for the shot was over 5 miles of 6-in. hole. The main blast consisted of 232 holes spaced on 17.5-ft.

Jan 1, 1934

By PAUL M. Tyier

NOW that analytical chemistry has gone so far to debunk early misconceptions about minerals, the fact that the light of exact knowledge still fails to illuminate many dark corners is often overlooked. By combining the skills of the physicist with those of a chemist, the identification of minerals has become an exact science and the presence of even minute traces of impurities and extraneous elements is readily revealed by spectrographic means, Granted that we can learn all there is to know about the composition of a substance and even about its physical propertied (which latter assumption is somewhat far-reaching) it still does not follow that we clearly understood its commercial designation or utility.

Jan 1, 1941

By Sanai Nakabe

Japanese wartime economy demanded domestic cobalt production. This paper describes a process operated for two years at the Besshi mine and smelter on extremely low grade (0.1 pct Co) pyrite concentrates obtained from copper ore. &apos;The steps in the process were roasting, leaching, precipitation, reduction fusion to crude cobalt, and finally refining by electrolysis to 99+ pct. COBALT ore deposits in Japan are all small and of poor grade. In the past, a small amount of cobalt has been produced from the best portions of a few of these deposits, and very little production is expected in the future. In addition to these lean cobalt ores, cobalt is present in the cupriferous pyrite which is fairly abundant although of low grade, as is shown in Table I. Considerable cobalt is expected from these deposits because of their extent. Cobalt cannot be exclusively recovered economically from ore of this type; however, if means could be devised to recover it as a byproduct of copper production, a fairly large production at reasonable cost could be expected from Japanese sources. It was along this line that the research work was done. Selection of Suitable Process The process for extracting cobalt differs from ore to ore according to their composition. The difficulty in cobalt metallurgy arises from the fact that chemically cobalt resembles many such common metals as Mn, Fe, Ni, Cu, and Zn, associated with it in the ores. In the present case the most serious difficulties were: 1—Extremely low grade ore, 0.1 pct Co. 2—The large proportion of iron accompanying cobalt and its close similarity in chemical behavior. 3—The fairly large proportion of zinc and manganese and their chemical similarity to cobalt. The recovery of cobalt oxide as a byproduct of the hydrometallurgy of copper had been attempted in Japan but was stopped after a short period because it proved uneconomical. The literature disclosed no method for the recovery of cobalt from cobaltiferous copper pyrite and it was therefore necessary to devise a new process. The following basic principles were considered in selecting the process: 1—A major alteration in copper production methods should not be necessary. 2—The first step should be the extraction of cobalt leaving the large quantity of iron unaffected. For this purpose wet metallurgy would be preferred.

Jan 1, 1952

THE Institute of Metals Division opened its series of meetings by a session* on lead, R. S. Dean be-ing in the chair and G. 0. Hiers acting as vice-chairman. A large and representative audience listened to the papers in the abstract and contributed an inter-esting and fruitful discussion. The main points of these papers and discussion are given below: In the absence of Carl E. Swartz, the summary and conclusions of his paper, "A Study of the Lead-Tin-Cadmium System with Reference to Their Use as Solders," were read. Swartz investigated a number of alloys in the lead-tin-cadmium system and prepared a diagram representing the solidification ranges of these alloys. He also made tensile strength tests of joints made with these alloys, and compared these with joints made with ordinary lead-tin solder. The tests showed solders containing cadmium were equally strong as the lead-tin series and that the cadmium alloys were suit-able in other respects for use as solders. In general, solders of the composition near to the ternary lead-tin-cadmium eutectic appeared to be the best for most soldering work although compositions widely differing are desirable for special purposes. The lead-tin-cad-mium solders are finding a market particularly in the fields requiring lower solidification temperatures than common solders. Mr. Darby opened the discussion and asked whether it was a fact that the lead-tin-cadmium solders were more useful than ordinary solders on galvanized and tin-plated sheet. C. Smith said he thought it to be a fact that galvanized sheet was more easily soldered by the lead-tin-cadmium solders than common lead-tin-solder. Continuing, Mr. Smith showed lantern slides of his own investigation of the thermal diagram and recommended the 70 per cent lead, 20 per cent cadmium, and 10 per cent tin for general employment. He thought the author did not differentiate between wetting and alloying and pointed out that wetting was more a ques-tion of the flux than the metal. In some cases a definite alloy was formed by soldering and in some no evidences of alloying were found. Illustrating the former case he showed slides and demonstrated that failures always took place longitudinal with the brittle compound alloy and transversely across the solder itself.

Jan 3, 1928

By Robert K. Warner

When a new mine is opened, and often when an operating mine must adapt itself to physical or economic changes, a mining system must be selected in complete detail. In the past the plan chosen was usually the product of the local staff alone, however limited the training and experience of that staff might be, which often resulted in the introduction of methods that were familiar to the staff, but not so well suited to the conditions as others unknown to the local men. A new management, noting the difficulties with the existing layout, might make modifications or complete changes, so that many mines in their history have seen a whole series of mining systems, each somewhat laboriously grafted on to its predecessor. This should not be interpreted as a condemnation of the older staffs for sticking to the tried systems, such as open square-sets in the early days at the Homestake, because they knew it would work after a fashion, nor does the statement apply to the technically trained, and usually broadly experienced staffs of most present-day properties. The older miners did not have the variety of tools and methods, nor the present freedom of transfer of information as to what the other man is doing, and so did the best they could under the circumstances. Finally, the higher grade of the ores made the choice less vital. The ever-increasing need to mine low-grade orebodies, with a fixed or even lower price for the metal produced, has caused an increasing need for low-cost mining. In most new mines this has simplified the problem of selection by eliminating from consideration all of the high-cost systems, but it has also complicated the choice by the necessity for refinement in detail and a close adjustment of the plan selected to all the conditions at the property. In these low-cost problems any textbook division of mining systems as applied to "beds, veins or masses" avails little as a guide. It should be realized at the outset that to be successful under modern competitive conditions a system of mining must be worked out with elaborate detail, with careful time scheduling and control of the various elemental operations, and that after it is introduced it must be run with a large amount of technical direction.

Jan 1, 1934

By M. E. Lombardi

THE Coalinga oil field is located on the west side of the San Joaquin Valley, California. The structure is in general a monocline, the edges of the oil horizon resting on the foot hills and dipping gently toward the east. One prominent anticline occurs plunging southeast. The earlier drilling was done in the foot hills comparatively near the outcrop and the wells were shallow. The sands were followed eastward and, in the case of the anticline, along the plunge, the wells becoming deeper and deeper until the depth of 4,000 ft. was reached and passed. There is nothing to show that the oil will not be found in quantity at still greater depth. In fact, some of the best producers have tapped the sand at close to 4,000 ft. The recovery of oil still farther to the east, and therefore at greater depth, seems to be mainly a question of drilling. In this territory the formations drilled through are chiefly sands and shales; they will not "stand up" in an open drilling hole; the casing has to be carried close to the bit, and it is always difficult to keep the casing free for any considerable distance. Ability to carry casing of comparatively large diameter without conductor pipes for distances of 2,000 or 3,000 ft. or over is desirable in such territory chiefly for two reasons. It makes it possible to enter the oil sand with a pipe of ample diameter; it eliminates one or more expensive strings of casing which act only as conductors for the water string, and furthermore, in territory where waters are encountered which corrode steel rapidly, it makes possible the construction of a rust- and alkali-resisting water string. It is always desirable to shut off top waters, which may lie within 100 ft. or less of the oil sand, with 10-in. pipe. Where the depth is so great that a practical weight of 10-in. pipe will not withstand the probable collapsing pressures, 8 ¼ in. at least is desirable. About the limit of rotary drilling to date in California seems to be the setting of the 10-in. string at 3,200 ft., although the rapid advance in rotary work during the past year seems to indicate that this depth may soon be increased. It is my purpose now, however, to treat only of cable-tool drilling.

Jan 2, 1915