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By N. Pessall, A. D. McQuillan

The phase relalionsllips in an isothernzal section of the Ti-Zr-H system at 750°Chave been investigated by measurement of hydrogen equilibrium pressures. The resulting diagram indicates that the hydride phase has an anomalously wide range of homogencity extending from 66.6 to 30 at. pct H in alloys containing about 15 al. pet Zr. Measurement of the heat of solution of hydrogen as a function of alloy composition in ß-phase alloys indicates no anomalous behavior in the region of 15 at. pet Zr, and suggests that the extensive range of homogeneity in the hydride phase at about this composition must he attributed to an enhanced stability of the, hydride phase. THE manner in which titanium and zirconium react with hydrogen and the constitutional diagrams of the two metal-hydrogen systems are qualitatively very similar,'-6 as can be seen from Fig. 1 which shows the constitutional diagrams of the two systems. Quantitatively, however, there are some differences. For example, the exothermic heat of solution of hydrogen in ß titanium is smaller than that in ß zirconium, and consequently the equilibrium hydrogen pressure of a Ti-H alloy is higher than a Zr-H alloy at the same temperature and hydrogen concentration. Other differences manifest themselves in the hydride phases which exist at high hydrogen concentrations. In the Ti-H system, above room temperature, there exists only a single hydride phase in which the metal atoms are arranged on a fee lattice, but in the zirconium system there are two hydrides, and whereas the hydride of lower hydrogen concentration has a fee structure, the higher hydride has a face-centered tetragonal structure. The tetragonal hydride retains its stability up to temperatures in excess of 450oC.7 From the foregoing, it would be expected that the constitutional diagram of the ternary Ti-Zr-H system would have a very simple form, especially as titanium and zirconium are completely miscible in both the a and ß forms.8 The present work, which consists of a study of an isothermal section of the ternary system, was carried out in order to check the assumption frequently made that the electronic structure of the two metals and the mechanism by which hydrogen is held in solution in the metals is the same for each. Although this proved largely to be true, certain inter esting and unexpected features of the ternary system emerged which must be explained before we can really say that the reactions of titanium and zirconium with hydrogen are fully understood. EXPERIMENTAL PROCEDURE The most convenient method of studying hydrogen-metal systems is by the measurement of the hydrogen pressure in equilibrium with the hydrogen dissolved in the metal as a function of hydrogen concentration and temperature. In binary systems, the results are easily interpreted in terms of alloy constitution, since two-phase regions can be recognized by the fact that the hydrogen pressure at constant temperature does not vary with the hydrogen concentration in the alloy when it is in the two-phase condition. This criterion does not apply in ternary systems, but there is usually a marked change of slope in the isothermal pressure-composition curves when a phase boundary is crossed, and with care, and a knowledge of the limiting binary systems, the phase structure of the alloys can usually be deduced. In the

Jan 1, 1962

By H. S. Kalish, F. J. Dunkerley

INTRODUCTION AND PREVIOUS WORK THE determination of the low temperature tensile properties of tin and tin-lead alloys was initiated as part of an extensive research program on the phasial equilibria of tin binary systems below 13.2°C and the property changes associated therewith. A survey of the literature revealed that, although some room temperature tensile data were available for tin and a few tin-lead alloys, there existed no survey report of the low temperature tensile properties of these alloys. Accordingly, the tensile data for tin and a series of pure tin alloys containing from 0.01 to 50 pct lead were measured at eleven temperatures from -196 to +20°C and are presented here in survey form. In addition to the importance of these tensile data as a preliminary to certain fundamental research, this information promises also to be of commercial importance because of the 'extensive use now being made of tin-lead solders in refrigeration and gas liquefaction equipment. Occasional failures of the solders in low temperature service have been attributed by some metallurgists to low temperature mbrittlement, while others hold that failure results from the transformation of the tin-rich phase of the solder from the solid white (beta) to the powdered gray (alpha) form. From the data previously available in the literature, neither of these explanations can be completely corroborated. Cohen and van Lieshout1 have established the beta to alpha tin transformation at 13.2°C and have shown that strain accelerates the transformation. Further, they showed that although I pct lead retarded the transformation, it was not eliminated. It will be pertinent, then, to note whether the beta to alpha transformation of the tin-rich phase will occur in a short-time tensile test. Polanyi and Schmid2 studied the tensile . properties of tin single crystals at -185°C and report that tin is brittle at-this temperature. In 1946, Kostenets3 reported that pure tin was brittle at -196 and -253°C, while lead remained ductile at both these temperatures. He also studied the tensile properties of tin-lead alloys containing from 10 to 75 pct lead at -253, -196 and +17°C. The ultimate tensile strength increased more than two times in going from room temperature to -196°C and about three times that value on further cooling to -253°C. All the alloys were brittle at -6°C except those containing more than 75 pct lead. Even at -253°C, the 75 pct lead alloy retained 36 pct elonga¬tion in a 30 mm-ga. length. Creep is also an important phenomenon

Jan 1, 1948

By William Hamilton Merritt

A brief paper on this subject (which might readily be made to, fill a volume) is suggested at this time by several considerations, among which may he named the meeting of the Institute on the borders of Ontario, not far from some of the mining undertakings which are hereafter mentioned ; the mineral developments made in the Province quite recently ; the highly creditable collection of most of the minerals of Ontario, for the first time got together, and exhibited this year at Cincinnati, in the Centennial Exhibition of the Ohio Valley ; and, finally, the recent appointment, by the Government of Ontario, of a Commiesion to inquire into, and report upon the mineral resources of the Province, and the best means to be adopted for their development. The Province of Ontario has no Department of Mines or official geologist, to take note, and keep record, of mining and mineralogical development and discovery. Within the last few years some valuable statistics have been collected by Mr. A. Blue, the Deputy Minister of Agriculture; but recently a desire has risen on the part of the people to obtain further knowledge of these subjects, and the government has appointed a Commission, the report of which is expected to be issued in part, if not in completed form, this winter.

Jan 1, 1889

By J. S. Kirkaldy, W. V. Youdelis

THE occurrence of concentration distributions in rapidly cooled castings with gradients of opposite sign to those expected on the basis of the constitution diagram and diffusion controlled kinetics, has long interested metallurgists. The work on inverse segregation to 1937 has been adequately reviewed by Vaughan, and to 1949 by ell-walpole. The general conclusion for unidirectional solidification, that the enrichment of the initially solidifying regions with lower melting point compositions is due to the flow-back along interdendritic channels of normally segregated residual liquid, has a very sound experimental basis. Perhaps the best experimental work and the most complete qualitative description of the process has been given by Adams.3 The authors accordingly assume the reader's understanding of the content of this paper. It appears that one of the principal deterrents to the complete understanding of the process has been the lack of an analytical description. Although a number of workers including Masing,4-6 Sauerwald,7 and Adams3 have attempted quantitative predictions,

Jan 1, 1959

NEW MEMBERS The following list comprises the names of those persons who became members during the period of June 10, 1917, to July 10, 1917. BANKS, LEON MAXWELL Agent 3. Supt., Grant Leasing Co. Metcalf Ariz. BEAUCHAMP, HENRY CLAY : Mine Operator, Sisson, Siskiyou Co., Cal. BOCKING, CHARLES, Asst. Mgr., Butte & Superior ,Mining Co., Rialto Bldg., Butte, Mont. BEYER, HERMAN E., Chief Engr., Condenser Dept., Ingersoll-Rand Co., 11 Broadway, New York, N. Y. BLACK, HERBERT F 1512 Oliver Bldg., Pittsburgh, Pa. BRENNAN, PATRICK J., Gen'l. Supt., Elkhorn Division, Consolidation Coal Co., Jenkins, Ky. BUTNER, DANIEL W., Chem. & Supt., Underground Min., Spanish American Iron Co., Daiquiri, Santiago de Cuba, Cuba. CARLTON, DAVE P Nevada-Douglas Cons. Copper Co., Ludwig, Nev. DE AROZENA, JOE Min. Engr., 321 Preusser St., San Angelo, Texas. DICKIE, CHARLES HERBERT, Pres., Georgia River Min. Co., Duncan, Vancouver Island, B. C., Canada. DOBBINS, WALTER Mill Foreman, Chino Copper Co., Hurley, New Mexico. DRURY, CHARLES W., Asst. Professor of Met., Queen's University, Kingston Out. Canada.

Jan 8, 1917

By C. P. Miller

In order to determine the usefulness of geochemical and biogeochemical prospecting for nickel, ten localities representing several types of nickel occurrences were selected as sites from which to collect plant and soil samples. This report covers the investigations in two of the areas. After a brief geologic description of the areas, the author presents details of the experimental tests and resulting data. Conclusions drawn from the studies led to several general guides for further prospecting. In a study of the usefulness of geochemical and biogeochemical prospecting for nickel made about three years ago, approximately ten localities, representing several different types of nickel occurrences, were sampled and about 1500 samples of plant and soil were collected. This report will cover briefly the data and results for two areas, and a summary of guides for prospecting. DESCRIPTION OF AREAS SAMPLED One locality is the Red Flats nickel prospect in Curry County, Ore., about six miles southeast of Goldbeach, and the other is the Little Rocky Creek prospect in Stillwater County, southcentral Montana, just southeast of the Benbow chromite mine. The Oregon area is a lateritic-type nickel deposit formed on a nickel-rich serpentinite peridotite complex, similar to the Josephine intrusion in southwestern Oregon. The Montana area is a nickel prospect in norite, peridotite, and related rocks of the Stillwater igneous complex. The Stillwater complex is a series of layered basic and ultrabasic rocks, with a layer of norite-gabbro at the base and a series of peridotites and gabbros above. The nickel in the Oregon deposit occurs in both the peridotite and the overlying soil. A deep lateritic soil is developed locally on the peridotite and serpentinite and constitutes the ore. The average nickel content of the lateritic soil is less than 1 pct, whereas the nickel content of the weathered peridotite is about 1 to 1.5 pct. The nickel occurs as garnierite (Mg, Fe, Ni, Mn)3 (OH)4 (SiA1)2O5 in the soil and in the olivine and pyroxene in the peridotite where it probably substitutes for Fe2+ or Mg2+ in the silicate lattices. Nickel is found in three distinct ways in the Still-water rocks: 1) it is in the olivine and pyroxene minerals in norite, harzburgite, etc.; 2) it occurs as widely disseminated grains of pentlandite-pyr-rhotite, which tend to be concentrated in the lower norite band; and 3) it occurs as discrete bodies of pentlandite-pyrrhotite and chalcopyrite which are localized in the norite zone, close to the contact with the underlying rocks. The nickel content of the norite is probably less than 1 pct, and the nickel content of the pods and lenses within the norite is about 1 pct. PROSPECTING APPROACH Although the areas are different geologically, the approach in prospecting them is fundamentally the same. The procedure is twofold: 1) a rapid reconnaissance survey to outline an area of high nickel content, and 2) a more detailed survey to outline zones of possible ore grade within the area of high nickel. The possible ore at Red Flats is concentrated in the lateritic soil, whereas at Little Rocky Creek it is in the sulfide pods. Both types are surrounded by an area of relatively high nickel content. CHEMICAL ANALYSIS Chemical analyses of nickel were made by a di-methylglyoxime colorimetric test, similar to the standard test for nickel, utilizing concentrated sul-furic acid for extraction. The lower limit of detection for nickel in soil by the method used was about 10 ppm and for nickel in plants about 5 ppm. The relative deviation was about 25 pct. SOIL PROSPECTING General Statements: A summary of the approximate average parts per million of nickel in soil, as compiled from the literature and from my study, is given in Table I. Selected references are given at the end of the paper. Few of the investigators reported the type of extraction or analysis, so the data given may not be strictly comparable to mine, which were made with a sulfuric acid extraction. Any nickel concentration greater than these average values might be considered anomalous, although each area must be studied in relation to the surrounding rocks. Method of Soil Sampling: The soil samples were taken in a zone from 1 in. to 1 ft below the humus layer, and within a 15-ft radius around a station.

Jan 1, 1961

By R. A. Kinzie

THE major operating costs in a cement plant are labor, power, and fuel. The opportunities and methods of savings in labor and power parallel other industries. Because our industry's use of fuel is large and its method of use is unique, the devices adapted for saving fuel are of interest. In normal practice the raw material in the form of a dry powder or a mud is fed to a rotating inclined cylinder where it is dried, calcined, and clinkered. In a Lepol kiln the raw material is rolled up into little balls with water in the nodulizer, fed to a traveling grate on which it is dried and partially calcined and tben to a short kiln where the process is finished. The more usual methods of saving heat have been the use of long kilns with chains in wet process plants and the use of waste heat boilers in dry plants (fig. 1). At the Santa Cruz plant we have used a Lepol system kiln and achieved a fuel 'economy of 4.7 gal per bbl of clinker or about 704,-000 Btu per bbl. This can be compared with our old kilns using the same fuel and raw material which consume 7.8 gal per bbl or 1,130,000 Btu per bbl. These are gross Btu and not the net figures usually used in reports of foreign companies. Our average consumption for 1948 was 708,000 Btu per bbl of Lepol clinker, based on cement sold, and oil purchased. The overall fuel consumption for 1948 was 6.61 gal per bbl. The Lepol system consists of a nodulizer, a grate, and a kiln. There is the usual accessory equipment which is similar to that used in other cement plants. The following description covers the equipment in operation at our plant. The nodulizer is a cylinder 8 ft 10 in. in diam by 18 ft long set on a slope of 1/2 in. per ft, and rotated at about 10 rpm. It is driven by a 50 hp wound rotor motor drawing about 9 kw. The inside of the shell is cleaned by a continuously operating scraper which draws 0.1 kw. The dry raw material is fed to the nodulizer where, being sprayed with water, it rolls into small spheres about 90 pct being between 1/2 and 1 in. in diam and containing about 15 pct water. The nodules fall on the traveling grate where the hot gas from the kiln is pulled down through the

Jan 1, 1951

By R. A. Kinzie

THE major operating costs in a cement plant are labor, power, and fuel. The opportunities and methods of savings in labor and power parallel other industries. Because our industry's use of fuel is large and its method of use is unique, the devices adapted for saving fuel are of interest. In normal practice the raw material in the form of a dry powder or a mud is fed to a rotating inclined cylinder where it is dried, calcined, and clinkered. In a Lepol kiln the raw material is rolled up into little balls with water in the nodulizer, fed to a traveling grate on which it is dried and partially calcined and tben to a short kiln where the process is finished. The more usual methods of saving heat have been the use of long kilns with chains in wet process plants and the use of waste heat boilers in dry plants (fig. 1). At the Santa Cruz plant we have used a Lepol system kiln and achieved a fuel 'economy of 4.7 gal per bbl of clinker or about 704,-000 Btu per bbl. This can be compared with our old kilns using the same fuel and raw material which consume 7.8 gal per bbl or 1,130,000 Btu per bbl. These are gross Btu and not the net figures usually used in reports of foreign companies. Our average consumption for 1948 was 708,000 Btu per bbl of Lepol clinker, based on cement sold, and oil purchased. The overall fuel consumption for 1948 was 6.61 gal per bbl. The Lepol system consists of a nodulizer, a grate, and a kiln. There is the usual accessory equipment which is similar to that used in other cement plants. The following description covers the equipment in operation at our plant. The nodulizer is a cylinder 8 ft 10 in. in diam by 18 ft long set on a slope of 1/2 in. per ft, and rotated at about 10 rpm. It is driven by a 50 hp wound rotor motor drawing about 9 kw. The inside of the shell is cleaned by a continuously operating scraper which draws 0.1 kw. The dry raw material is fed to the nodulizer where, being sprayed with water, it rolls into small spheres about 90 pct being between 1/2 and 1 in. in diam and containing about 15 pct water. The nodules fall on the traveling grate where the hot gas from the kiln is pulled down through the

Jan 1, 1951

[A Editor's Note: Annual Reviews of various subjects and areas are found in February issues of Mining and Metallurgy and Mining Engineering. These Annual Reviews are not listed per se in the Index. Abating Stream Pollution in Anthracite Coal Fields. ME Mar 50 Abbadia San Salvatore mine, Italy. T178, 297 Abbott, C.E.: Limestone Mine in the Birmingham District. With Discussion. T129, 62 ABC Typifies Trend to Mechanized Mining and Coal Preparation. ME Dec 50 Abel, J.F.: Statistical Analysis of Tunnel Supporting Loads. T235, 288 Sulzbach, J. F., and Walker, D.K.: Ice Tunneling in Greenland. ME Jun 59 Aberfoyle tin mines, sphalerite, chalcopyrite, stannite, as intergrowths. T214, 1147 Abnormal Behavior of Some Ore Constituents and Their Effect on Blast Furnace Operation, The. T241, 1 Abrams, C.J.: Industry's Responsibility in Postwar Economy. M&M Mar 45 and Haley, D.F.: History of Crushing and Milling at Climax. M&M Jun 46]

Jan 1, 1972

By G. W. Tracy, R. D. Carter

Numerical calculations were made to determine the behavior of reservoirs with high-pressure drawdown and wide well spacing where the initial productivity is low and the wells are completed by hydraulic fracturing. The two-phase flow equations were solved for the flow into a single well. This well was assumed to be producing from a reservoir with hydraulically created horizontal fractures (four different systems with fractures were studied). For comparison purposes, additional two-phase flow calculations were made assuming a reservoir with uniform rock properties. The two-phase flow results were also compared with the conventional calculation methods, which do not include the effect of saturation gradients resulting from a simultaneous flow of oil and gas which are normal to this type reservoir. It was found that the conventional methods predict (1) a high and too optimistic value of ultimate recovery, (2) a high producing rate and a high reservoir pressure at a given oil recovery and (3) a low trend of gas-oil ratio with oil recovery. Included in the two-phase flow calculations were provisions to control the oil production rate by an allowable rate and, also, by a gas-oil ratio penalty rule. For the systems with hydraulic fractures, the producing rate was controlled by the gas-oil ratio penalty rule for most of the life. This is in contrast to the system with uniform rock properties which went "on decline" almost immediately. An unexpected characteristic of the systems which included fractures was the early rise in producing gas-oil ratio from 730 cu ft/bbl to approximately 1,200 cu ft/bbl, followed by a "leveling off" before the normally expected gas-oil ratio rise began. Additional features which are a result of hydraulic fracturing are (I) greater ultimate recovery, (2) higher average producing rates and (3) a lower average reservoir pressure at a given oil recovery. INTRODUCTION Some oil fields discovered during the past few years are producing from certain volumetric ally controlled reservoirs (often referred to as solution or internal gas- drive reservoirs) which are characterized by high-pressure drawdown at the wells. Since the available pressure drawdown at a well is limited by the static reservoir pressure and the producing rate is controlled by the available drawdown, wells completed in this type of reservoir usually produce at a rate less than the allowable from the time of completion. Because of this, this type of reservoir is referred to as a low productivity reservoir. Economic considerations require the use of wide well spacing and well stimulation by hydraulic fracturing to make commercial wells in this type of reservoir. Performance predictions for volumetrically controlled reservoirs have been made using a combination of two standard equations. 1. The "Schilthuis" or "Muskat" type material balance equation is used to relate the average reservoir pressure and the cumulative oil recovery. 2. The results from the material balance equation and the productivity factor as described by Pirson' are used to relate the cumulative recovery with producing rate and time. The material balance equation assumed uniform pressure and liquid saturation conditions throughout a reservoir. The steady-state radial flow formula allows for a pressure gradient toward a well but assumes uniform liquid saturation. These calculation methods are adequate for application to reservoirs wherein the drawdown at the well to realize satisfactory producing rates is small compared to the total pressure. In low productivity, volumetrically controlled reservoirs, the pressure drawdown at the well is large cornpared to the total pressure. Although a precise number cannot be given for the magnitude of a large pressure drawdown, values in excess of 1,000 psi would definitely be included. For practical considerations, this usually occurs when the formation flow capacity is less than about 100 md-ft. However, this limit of formation flow capacity will vary with the well producing rate. The low pressure in the neighborhood of the well which results from a high drawdown causes evolution of large volumes of gas. This causes the gas saturation to be higher near the well than at a greater distance—-hence, a non-uniform gas saturation. Also, the relationship between the relative permeability to oil (K/K) and gas saturation is nonlinear but decreases approximately in an exponential way with increases in gas saturation. Because of this, the following chain reaction is established.

By Jack Haptonstall

INTRODUCTION The mines of western central Mexico historically contributed a profusion of gold and silver for the treasury of Spain and later provided sources for financing the Mexican War for Independence and the Mexican Revolution. The western coastal and barranca (cliff) tribes were hunters and extremely hostile, and the Spaniards were not able to penetrate many of the rich districts of their rugged homeland until the mid-1700's. This was more than 200 years after Cortez began the Inquisition by defeating the Aztecs and their allies in a decisive battle in the great city of Tenochtitlan (present day Mexico City). The Spaniards had a voracious appetite for silver and gold, and it was inevitable that they would finally subdue the natives and commence mining activities. Described in this paper are some of the precious metal mining activities in the southern half of the State of Sinaloa and the western half of the State of Durango (Figure l), and specifically those mining activities in the area controlled by the company with which the author was associated for 14 years, Minas de San Luis, S. A. de C. V., the parent company of which is now Industrias Luis Min, S. A. GENERAL DESCRIPTION Geography, Logistics and Climate The most spectacular of the physiographic provinces, the western Sierra Madre Occidental is the cliff or "barranca" province, the

Jan 1, 1983

By A. E. Nehrenberg

R. A. Schmucker, Jr.—The writer wishes to point out that an acicular growth of austenite, similar to that described in the author's paper, was recently observed in an alloy steel of only 0.06 C content. This steel, which represents an 0.07 max C, 1.35 Cr, 0.55 Ni, 0.20 Mo analysis, combines the characteristics of minimum hardness in the annealed condition with maximum hardenability and is therefore suited primarily for cold-hobbing applications. The acicular austenite formation in this steel was observed accidentally during a determination of its Ac1 temperature. The samples used in this investigation represented as-forged bar stock which had been given a preliminary temper at 1300°F. The critical (Ac1) temperature was finally established at 1400 °F. Fig. 15 represents the microstructure of the sample which had been heated at 1450°F for ½ hr, water quenched, and tempered at 600°F for ½ hr (for the purpose of darkening the martensite). It will be observed from the distribution of the darkened areas of martensite that the parent austenite grains formed at 1450°F had grown in an acicular manner and still occupied only a small percentage of the total area. The remainder of the area contains the original equiaxed ferrite grains in which new austenite had as yet scarcely formed. However, the tiny isolated martensitic patches at several points where three or more ferrite grains intersect indicate that small austenite grains had formed and started to grow in an apparently equiaxed fashion. Fig. 16 represents the prior microstructure of an original sample in the as-forged and tempered condition, before it was heated -above the critical temperature. It is probable that there are two kinds of ferrite in this structure: (1) The equiaxed proeutectoid ferrite grains which separated from the austenite when the steel was cooled from the forging temperature, and (2) the acicular ferrite associated with the aggregate of fine carbide which is represented by the patches of

Jan 1, 1951

By Smith, George Otis

THE matter that I have on my mind this evening is engineering's need of an open forum. Our fathers of three centuries ago were pro-testanta for freedom of speech and thought in matters religious; later, our fathers were revolutionists for freedom of speech in matters political; until today freedom of speech has become so universal throughout the land that even in the sanctuary of our homes, at times, we have to turn off the loud-speaker. Talk is not always a condition of progress, but light is everywhere necessary to growth, whether the growing thing is a blade of grass, a baby chick, or a young idea, and we must regret anything that tends to shut out the light from the operations of business and industry. Of course, I realize there is little that is novel in what I am saying. Indeed, I have found that Dr. James Douglas-a name we love to honor in our Institute-as long ago as 1907, gave an address at the Toronto meeting that any of us would be proud to be author of twenty-one years after. Dr. Douglas at that time spoke on secrecy in the arts and the text then taken by this leader in metallurgical technique and in the constructive management of big business was "the dangerous temptation to adopt secretive methods by very large corporations." In both thought and language Dr. Douglas was direct and vigorous and he needs no internreter. He advocated the wide open door for ideas on two counts: advancement of technical knowledge and education of public opinion. A few sentences will serve not only to prove the vision of James Douglas, but also, I hope, tempt you to hunt up his address in the Institute's TRANSACTIONS, and thus get his whole thought first hand.

Jan 1, 1928

By Mason K. Banks

A process has been developed which produces spodumene concentrates assaying 6.0 pct Li2O and 0.45 pct Fe2O3, with 70 to 75 pct recovery of spodumene. Two flotation separations are required: the simultaneous removal of mica, feldspar, and quartz as a froth product using a cationic collector, and the subsequent removal of iron-bearing minerals as a froth product while spodumene is depressed as a tailing. SINCE the close of World War II there have been numerous developments resulting in the increased use of lithium by industry. Notable among these has been the development of an industrial lubricant, based on lithium stearate, which is fluid at low temperatures, stable at high temperature, and insoluble in water. A new bleaching agent, lithium hypo-chlorite, has also been developed recently.' Other well-known uses are listed below: 1—Lithium oxide in ceramics reduces firing time, lowers melting temperatures, lowers thermal expansion, raises refractive index, and improves chemical resistivity. 2—Lithium carbonate and lithium strontium nitrate are used in pyrotechnics for their brilliant red color.' 3—Lithium chlorides and fluorides are used as fluxes for welding aluminum and magnesium.' 4—The affinity of lithium for nitrogen is the basis for a process used in purifying helium." 5— Lithium chlorides and bromides are used in air conditioning for their powers to absorb organic amines, ammonia, and smoke.6-—Lithium hydride has been used as a source of hydrogen to inflate life rafts and balloons used by the Air Forces and Navy.' 7— Lithium metal and lithium hydride are useful in the atomic energy program in connection with the production of the isotopes of hydrogen." During the 1942-45 period of World War 11, Solvay Process Co. operated a flotation plant with a daily capacity of 300 tons of ore for the production of spodumene concentrate near Kings Mountain, North Carolina. The operation was shut down upon reduction of wartime demand for lithium chemicals, and until recently there has been no production from the Carolinas. In April 1950 an investigation of the problem of spodumene flotation from North Carolina ores was begun at North Carolina State College Minerals Research Laboratory at Asheville, N. C. This laboratory, operating under the combined auspices of North Carolina State College, North Carolina Department of Conservation and Development, and the Tennessee Valley Authority, undertook the spodumene project at the request of Foote Mineral Co. of Philadelphia. The work, involving a period of 15 months of intensive batch and pilot plant investigation, was completed in June 1951 and resulted in development of a process for concentration of spodumene by flotation which has been hereto unrecorded in the literature. A similar approach has been used before on iron, ilmenite, and other minerals, but the literature shows no record of its having been applied to spodumene. Parts of the process are now being used on a commercial scale at the Foote Mineral Co. plant near Kings Mountain, N. C., which has been in production since July 1951. It is the purpose of this paper to describe some of the results of the investigation. The Orebodies Spodumene-bearing pegmatites occur in a narrow belt 24.5 miles long and 1.8 miles wide extending southwestward from Lincolnton to Grover, N. C. According to statements judged to be conservative, the tin-spodumene belt of the Carolinas contains an estimated 4,300,000 tons of pegmatite ore averaging 15 pct spodumene. This amounts to "a reserve of at least 650,000 tons of spodumene (more than 20,000 tons of metallic lithium) to a depth of 100 ft."' This figure includes only bodies having an average thickness of 35 ft and length of 550 ft. There are hundreds of pegmatites in the belt, many of which are less than 10 ft wide. The largest pegmatite in the area has a maximum thickness of 395 ft and maximum length of 3250 ft.' These larger pegmatites are composed principally

Jan 1, 1954

By John Henry Harden

THIS shaft, located in the northern anthracite coal-field about 2300 feet southwest from the court-house at Wilkes-Barre, in the County of Luzerne, Pa., is the property of the Lehigh & Wilkes¬Barre Coal Company. The sinking and cribbing to the solid rock (see isometrical view on Plate IX) was conducted by Mr. W. W. Kenrick. Dimensions of the earthwork to the foundation of the cribbing, 51' 1/2" long, 17' 4" wide, 31' deep. Total amount of excavation in cubic yards, 998.5. Dimensions within the permanent cribbing, 45' 4" long, 11' 16" wide, 31' deep, divided into six parts by buttons 8" x 12", each division, 7' x 11’ 16". Permanent cribbing 12" x 12"; temporary cribbing 8" x 10"; backing, 3" thick ; clay puddle to ex¬clude surface water, 12" thick; conductors, 8" x 5"; lining, 1" thick from top to bottom of the shaft. In the latter part of the year 1871, Mr. H. Murray & Son contracted with the company for the continuation of the work at the rate of four hundred dollars per yard in depth, to a point 100 feet below the Hillman seam of coal ; for the succeeding 100 feet the price to be increased twenty-five dollars per yard, and so on until the bottom rock of the Baltimore seam of coal was found. The size of the shaft within the cribbing timbers is 45 feet 4 inches by 11 feet 6 inches, having six divisions of equal dimensions, 7 feet by 11 feet 6 inches, giving room for what is known as the" standard diamond" car, whose capacity when level full is 100 cubic feet, but when loaded by the miner 4 inches above the top contains 112 cubic feet.* Two divisions of this shaft are intended for hoisting coal from the Hillman seam, two from the Baltimore seam, one for ventilation, and one for pumps. The works were planned for two pairs of direct-acting, high-pres¬sure engines, twenty-four boilers, and for an estimated output of 2500 tons of coal per day from the two seams. * Size of the "standard diamond" car, 8' 10” x 4' 3" x 2’ 8” = 100.1.4; loaded 4 inches above the top, 8' 10” x 4’ 3” x 3’ “0"= 112.7.6.

Jan 1, 1877

By George A. Jr. Dornin

A TRULY sound ingot can be made only from steel that is completely deoxidized. Given this condition, there is one further basic requirement-the steel in the ingot must solidify progressively from the bottom to the top. Any method of making the ingot that produces this type of solidification will yield sound products. Since a big-end-down ingot will not satisfy this condition, all sound steel today is produced in big-end-up ingots, the standard tool being the big-end-up mold fitted with some sort of refractory hot top. No one uses hot tops from choice, be cause of the bother and expense involved and because of the low yield resulting from their use-they are used because there has been no alternative where sound steel was required.

Jan 1, 1947

By H. P. Rassbach, E. R. Saunders

MUCH progress has been made in recent years in the theory and practice of making stainless steel. By effective utilization of oxygen for decar-burization and more suitable alloying agents, it has been possible to attain consistent production of very low-carbon stainless steel. In order to facilitate economical production of stainless steels, the Electro Metallurgical Co. has carried out an extended experimental program that has clarified some of the complex interrelations of temperature and composition under decarburizing and reducing conditions. These results'-:' have been founded in large part on small experimental heats, and in order to confirm their validity and significance under commercial conditions, a survey of stainless steel melting practice has been made with the cooperation of stainless steel producers. Conditions required for decarburization and associated oxidation of chromium, manganese, and iron have been fairly well established in relation to the beneficial effect of the highest practicable temperature. The recovery of chromium and manganese from highly oxidized slags by reduction with silicon has been indicated with somewhat less precision and this study has shown significant deviation in large commercial heats from the small experimental heats. In spite of an unsatisfactory degree of accuracy in estimating the conditions affecting reduction of metallic values, it has been possible to calculate a slag weight in reasonably good agreement with the results observed in large heats. While there still is much to be learned about both the qualitative and quantitative aspects of stainless steel melting, this survey has indicated the manner by which the efficiency of the production process may be measured. Oxidation Period In order to establish practices for the recovery of chromium and manganese from the slag the amounts of these metals oxidized should be known. Moreover, since reduction of oxidized chromium and manganese must necessarily be accompanied by similar reduction of iron, knowledge of the total quantity of metallics oxidized is essential. The relations between carbon, chromium, and temperature under oxidizing conditions were developed by Hilty in 1948.' While it had been realized previously that retention of chromium in the metal during carbon oxidation is favored by high temperatures, the Hilty relation provided quantitative information useful for evaluating melting procedures. For example, it was shown that decarburization to moderate carbon levels can be achieved while retaining substantial amounts of chromium. However, in decarburizing to the low-carbon level necessary for producing 0.03 pct maximum carbon stainless steel, very little chromium remains in the bath at the temperatures generally employed. For this reason, Hilty, Healy, and Crafts' later projected an extension of the chromium-carbon relation to the low-chromium region. Although this chromium-carbon-temperature relation defined the composition of a chromium steel bath at the end of the oxidizing period, it did not provide a direct means for estimating the total amount of metallic oxidation occurring during decarburization of a stainless steel heat. This subject was investigated by Crafts and Rassbach³ and, later, by Hilty, Healy, and Crafts" who demonstrated that metallic oxidation is a function of the chromium content of the initial furnace charge, the minimum carbon content attained, and the temperature. It was further demonstrated from data on 1-ton heats that an empirical relationship exists between the ratio of chromium plus manganese to iron in the slag (S) to the corresponding ratio of these components present in the metal bath. The following expression was derived to permit the calculation of the amount of metallics oxidized during decarburization of a given charge: W-2000 (Cr1 + Mn1)-(Cr2 + Mn2) 1 100s/s+1-(Cr3 + Mn2) where W is the pounds of chromium, manganese, and iron oxidized per ton of charge; Cr1, the percentage of chromium in the charge; Mn1, the percentage of manganese in the charge; Cr2, the percentage of chromium in the bath after oxidation; Mn2, the percentage of manganese in the bath after % Cr + % Mn oxidation; and S =%cr+ % Mn/%Fe in the slag after %Fe oxidation. In order to establish whether the slag ratios of commercial heats are consistent with those found in the experimental heats, the slag and metal analyses shown in Table I were evaluated. These data represent samples taken after the oxidation of two 1-ton and seven 15 to 25-ton heats of types 303, 304, and 304L stainless steel made in chromite, acid, and basic hearths. Fig. 1 illustrates that the results for the commercial heats correlate reasonably well with the relationship originally established for experimental 1-ton heats. It will be noted that in the range of metal composition of these heats, the slag values generally lie above the line. As was suggested by

Jan 1, 1954

J. J. RUTLEDGE,* McAlester, Okla. (written discussiont).-Research work has often a more immediate and practical application to the in-dustries than even the investigators themselves realize, but coal mining has not attracted the investigator, except in so far as the mine-accident prevention work and fuel investigations are concerned. In future, the coal geologist will study the subsurface geology of the various coal seams as the petroleum geologist now studies the oil sands, and from the results of these studies the coal operator will be able to locate his shafts to the best possible advantage and to avoid faults that would interfere with underground work. There would have been many thousands of dollars saved, and perhaps some reputations, if a good stratigrapher. had been called into consultation in the southern part of Somerset County, Pa., where a local seam of coal, quite thick, was mistaken for the Pittsburgh seam, which, if ever present at that point, had long since been eroded. Why will the Quemanhoming coal carry more sulfur without injuring the grate bars than George's Creek Big Vein? Only the investigator can answer and yet the fact that the above is true means a greater price for the thinner coal. The owner of the land in Oklahoma receives one-fourth of the cotton crop produced by the tenant who farms his land and one-third of the

Jan 11, 1919

By G. Ferrara

The reserves of lead and zinc ores in the metalliferous district of Iglesias in south-western Sardinia are today estimated at about 30 million tons, grading from 4 to 10% Pb + Zn. Of these reserves, about 40% are in the mines owned by AMMI Sarda S.p.A. The working of these resources goes back to ancient times. Not infrequently, traces of old Roman workings and remains of ancient implements are come upon in the higher parts of some of the ore bodies. Exploitation of these mines on larger scale, however, dates from the middle of the 18th century. Initially, the more accessible zones of the ore bodies and the richer ores were worked - the galena and the rich oxidized ores (calamine* with 25-35% Zn), which were often found in large masses, the enormous empty cavities of which still remain. The poorer grade deposits have been gradually rendered workable by the development of technology - the perfecting of the

Jan 1, 1970

and would also contribute to the post-war employment. -As far as the future is concerned, I doubt whether any of the present geophysical methods will ever be developed to directly indicate ore. However, the geochemical methods and certain combinations between chemical and geological methods now used might be the answer to our prayers for direct and more definite methods of determining the quality of the ore or its relative metal content. Geochemical and spectrochemical analysis of minute content in ground waters, in soil or in plants and trees, living or dead, will be extremely important and I would venture to predict that in the very near future each mining or exploration company and each assay oflice will have its own spectroscope equipped for accurate chemical analysis, not only to guide the daily work in the mine, but also for identifying ores as well as for guiding exploration, geological mapping and the evaluation of geophysical indications. These methods, although they are still in their infancy, promise very much for the future. Radioactivity methods could also be helpful when sufficient facilities for radioactivity determination can be made available. They have already been used to a great extent in oil exploration and experiments have shomn great promise for ore exploration also. As for future surveys of large areas, the exploration for physical contrasts will be made from the air, using aeroplanes, helicopters, etc. Already electrical and magnetic methods have been designed whereby the instruments are carried in the aircraft and by automatic recording the location of anomalies is made in a simple enough manner. It should be possible in this way to cover, say, a square mile in an hour. Later Discussion Replies to Dr Lundberg. J. B. Macelwane.*—Someone has said that if a person knows his subject well enough he can explain it in words of one syllable. The point is well taken and I think the converse is also true. If a person cannot explain a subject clearly in simple words, it is either because he has not sufficient command of the language, or he is not master of his subject. Now it is obvious, it seems to me, that the remedy for both of these unfortunate conditions lies not in less education, but in more. If Dr. Lundberg has met geophysicists who confused and discouraged prospective clients by their inability to talk the language of the mine owner or of the mining engineer or geologist, the fault most probably lay in the geophysicist's lack of sufficient training; but it may also have been the want of ordinary common sense, which no amount of education can supply. It is hard to understand the position taken by Dr. Lundberg. Does he regret his own extensive training? noes he wish to say that he would have had greater success in geophysics if he had been only a mine hand with an instrument and a rule of thumb? As a matter of fact, I find it rather difficult to account for his presentation before this Committee on Geophysics of an emotionally distorted picture of the Report of the Committee on Geophysical Education, after the lapse of an entire year since the Report was read and discussed in its proper place, unless he honestly thinks he is handicapped by his knowledge and training and wishes to warn the whole profession against a similar fate. I regret that I am obliged to disagree so emphatically with Dr. Lundberg's thesis— but I believe it would be dangerous if left unchallenged, both because of the inaccurate statements it contains concerning the recommendations made in the Report and because of the ultimate discredit that would be bound to fall upon genuine geophysics if Dr. Lundberg's recommendations were extensively followed out. S. F. Kelly.*-—The argument that a science and its practitioners can be improved by debasing the standard of educational preparation is indeed a strange argument to come from the pen of a man with the education of Dr. Hans Lundberg. In criticising the Committee report, moreover, he has to a certain extent set up a straw man to belabor. The statement that the Committee report recommends that

Jan 1, 1946