Search Documents

By C. Perez-Rosales

A simplified method for evaluating specific surface of porous media is described. The theory takes as its point of departure a previous statistical method. Due to its simplicity, it is considered that the proposed method has certain advantages over methods currently used. By making some simplifications, the procedure for estimating specific surface is reduced to superposing, on an enlarged reproduction of a section of the sample to be analyzed, an evenly spaced grid and counting the number of intersections of the grid lines with the perimeter of pores. An indirect test of the theory is presented and the advantages of the method are discussed. INTRODUCTION The specific surface of a porous medium, defined as the surface area of the pores per unit bulk volume, is an important parameter with regard to flow of fluids through porous materials. In particular, it has long been recognized that specific surface is closely related to permeability. Since the internal surface of any porous material is extremely complex, the measurement of specific surface can only be accomplished by indirect means. It is considered that the best method' in current use for determining specific surface is the statistical method of Chalkley, Cornfield and Parka who originally applied it for estimating volume-surface ratios of morphologic components, such as cells or nuclei. This method will be outlined later. A method which has been used extensively in determining specific surface is based on the adsorption of a vapor by the internal surface of porous media. However, this method does not yield the surface pertinent to fluid flow, since it includes the tiny molecular interstices which do not influence the permeability of the porous material.' This method has been employed by Brooks and Purcell measure internal surface area of sedimentary rocks. The Kozeny equation, which relates the specific surface to the permeability of a porous medium, has found wide use in determination of specific surface. However, the KOzeny equation is not strictly correct. Large discrepancies have been found between theory and experiments.' Consequently. the specific surface estimated by this method is subject to serious uncertainties. Finally, there are other methods for specific surface measurements which are based upon a variety of physical and chemical properties: the heat conduction by a gas, ionic adsorption phenomena and direct chemical reactions of the surface with other substances. This paper describes a simplified statistical method for determining specific surface of porous materials. It is considered that, due to its simplicity, it has certain advantages over the methods presently used. For its validity, it is required that the porous structure of the material under study be of a spatially random nature. This is not a serious limitation since the naturally occurring porous media have this characteristic. THEORY The method proposed in this paper takes as its point of departure the interesting result obtained by Chalkley et al The method shows that if a line of length r is dropped repeatedly at random over a section of a porous medium, and counts are made of the number of times the two end points fall within pore areas (denoted by h for "hits") and the number of times the line intersects the perimeter of pores (denoted by c for "cuts"), then in a very large number of throws where S is the internal surface of the sample (surface of pores) and V, the volume of the pores (Fig. 1). Since the specific surface S, and the porosity 4 are given, respectively, by S. = Sl V, and 4 = V,l V,, where V, is the total volume of the sample, it follows from Eq. 1

By Paul Billingsley

THE mining districts of the first and second order1 of the western United States (and borders) are those named on Fig. 1. These fall into four groups: (1) in the eastern outliers of the Rocky Mountain system; (2) in the Rocky Mountain system itself; (3) in the Great Basin; and (4) in the Sierras and Coast ranges. Of these four groups, the first three are almost entirely of Tertiary age and are within a belt of Tertiary compres-sive folding which we shall call the Rocky Mountain-Great Basin thrust arc. The backbone of this belt is shown by the line BAC. The position of the ore districts in this belt indicates a conformance to linear elements of the continental pattern. These are additional to the peripheral elements emphasized by Butler.2 NATURE OF THE THRUST ARC The thrust arc separates regions of contrasted kinds. To the east of it are flat-lying plateaus interrupted by earlier mountain folds; to the west, sunken basins, in which block-faulted ranges lie like an anchored fleet in a sea of desert wash or lava. The cross-sections are as shown in Fig. 2.

Jan 1, 1933

By John H. Schemel

Large Zircaloy-2 hammer or press forged bars did not exhibit the uniform excellent corrosion resistance to steam normally expected of the alloy in wrought form. Weight gains of coupons cut from forged bars were 40 to 60 mg per sq dm compared to the 28 mg per sq dm obtained on hot rolled sheet and strip. The mechanism of this corrosion and its relation to microstructure is discussed. After these observations, a solution heat treatment followed by rapid cooling was tried on coupons from eight heats of forged bars. The basket-weave structure resulting from the quench did not show agglomeration of intermetallic compounds. These coupons showed uniformly good corrosion resistance with weight gains very close to the 28 mg per sq dm expected of Zircaloy-2 after the 14-day steam test. A large forging was solution heat-treated and tested for structure, mechanical properties, and corrosion resistance. Corrosion resistance was excellent and uniform throughout the section. The normally anisotropic mechanical properties were changed to completely iso-tropic. Strength levels were raised while there was a small loss in ductility at the service temperature. Tempering of the quenched structure below the ß transus did not improve the ductility at the test temperature of 600°F. ZIRCALOY-2 end caps for nuclear fuel elements Zircaloy-2 is an alloy of 1.5 pct Sn, 0.1 pct Fe, 0.1 pct Cr, and 0.05 pct Ni, balance hafnium-free zirconium patented by Westing-house Electric Co. used in pressurized water reactors are machined from large hammer-finished forged bars. The bars forged for this application range from 3 1/2 in. to 7 1/2 in. squares. One of the tests used to evaluate Zircaloy-2 for this service is a 14-day exposure to very high-purity steam at 75oF and 1500 psi pressure. Normally wrought products will exhibit a black lustrous film of zirconium oxide after the test and show a weight gain of approximately 28 mg per sq dm. Coupons representing the forged bars exhibited a wide variety of corrosion results ranging from acceptable black coupons to some covered with white crystals of zirconium oxide that had weight gains of nearly 100 mg per sq dm. One of the most common effects was a white corrosion product that looked like a stain to some observers and the outline of massive metal grains to others. Very careful specimen preparation prior to the corrosion test did not affect the result and metallographic examination did not reveal a structural feature of a size and shape that would correlate with the corrosion product. In addition to the relatively poor corrosion resistance, the forged product was not as ductile as desired. The problem of obtaining uniform and more acceptable properties in these heavy-forged sections seemed to be a function of the microstructure of the metal and, in particular, the distribution of the intermetallic compounds. None of the four alloying elements however are appreciably soluble in a zirconium and are present as compounds which usually appear scattered randomly throughout the structure. Moudryl showed that the distribution of these intermetallic compounds in Zircaloy could be related to a ostringero corrosion failure. Grozier et al. discussed another structural defect that causes a similar corrosion effect. In this case, an elongated gas-void was determined to be the cause. M. L. Picklesimer held in his discussion of the Grozier paper that at least a part of the observed =stringersn were caused by the distribution of the intermetallic compounds. He proposed a

Jan 1, 1962

By P. Chiotti, E. R. Stevens

The electromotive force between pure magnesium and Mg-Zn alloys in a fused KC1-LiCl-MgC12 cell was measured over the temperature range 360° to 730°C and for alloy compositions of 0.052 to 0.635 atom fraction magnesium. The calculated activity coefficients of magnesium in the liquid alloys may he represented by the relation These data and the phase diagram were employed in calculating the standard free energy of formation for the compounds MgZn, MgZn2, and MgZn2, In the temperature range from 25° to 590°C the relation ZINC-rich magnesium alloys have been shown to be very effective in reducing various solute chlorides or oxides from fused salts such as KC1-LiC1 eutectic. Such reactions are of interest in the developinent of pyrometallurgical methods for reprocessing nuclear reactor fuels.' As the conceniration of the magnesium is increased beyond 5 to 10 wt pct the extent to which solutes, such as yttrium, lanthanum, cerium, and other rare earths, can be reduced or removed from the salt decreases. This effect is due to the resulting change in the activity of the solutes in the Zn-Mg alloy as well as the change in the activity of both the zinc and mag- nesium. The purpose of the present investigation was to determine the thermodynamic properties of the Zn-Mg system which, in addition to yielding information on the alloying behavior of these two elements, would permit a more quantitative understanding of the above reactions. Since this investigation was initiated several publications have appeared in the literature giving results on the thermodynamic properties for the liquid alloys of this system. 2-4 Kozuka, Moriyama, and Kushima3 measured the vapor pressure of zinc over four different alloy compositions by a carrier-gas technique. Eremenko and Tukashenko2 and Terpilowski4 measured the electromotive force between pure magnesium and various alloys in a fused salt cell. Earlier work has been summarized by Hultgren, Orr, Anderson, and Kelley.5 In the present investigation electromotive-force measurements were made on a cell of the type The temperature range covered for the lower-melting alloys was roughly 375° to 730°C. These data were employed in calculating the thermodynamic properties for the liquid alloys and in conjunction with the phase diagram,' reproduced in Fig. 1, were used in calculating the standard free energy of formation of the compounds MgZn, MgZn2, and Mg2 Zn11. The results obtained are compared with available data from the literature. MATERIALS AND EXPERIMENTAL PROCEDURES Materials employed were: Bunker Hill slab zinc, 99.99 pct pure; Ames Laboratory magnesium containing 13 ppm N, 195 ppm C, and trace amounts of calcium, copper, nickel, and silicon; reagent grade KC1, LiC1; and high-purity MgC12 obtained from Dow Chemical Co. The electrolyte consisting of KC1-LiCl eutectic (44.4 wt pct LiC1) to which was added 15 wt pct MgCl2, was dried in a quartz tube by heating to 340° C under vacuum for a period of 4 to 5 hr, and then passing HC1 through the salt as the temperature was slowly raised to above the melting point of the salt. After about 3 hr the HC1 was shut off and the system flushed with argon and then vacuum applied for 1 hr. The salt was finally siphoned through a sintered glass filter and cast into a Pyrex container which was sealed and

Jan 1, 1965

By N. Mohan, A. K. Biswas, V. Y. Sampat Kumar

At low sodium-oleate concentration, calcite flotation is substantially improved by the use of CO2 instead of air. Electrophoretic mobility measurements indicate that carbonation results in the accumulation o f positive charge on the calcite particles. This heightens adsorption of oleate anion, an effect confirmed by tracer-technique measurements. Fundamental insight is obtained as to how CO2 serves better as an activator than some mineral and organic acids, how oxalic acid acts as a depressor, and why the influence of Ca++ ions, liberated during carbonation, on flotation behavior of calcite is insignificant and sometimes adverse.

Jan 1, 1972

By E. Ryba, D. J. Michel

SAMPLES of REZn2 (RE = rare earth) intermetallic compounds prepared by a variety of techniques have been shown to exhibit an extensively twinned micro-structure.1-4 We have recently conducted compression tests at room temperature on specimens of HoZn2 prepared by a powder metallurgy technique.' The microstructures of specimens before and after testing are shown in Fig. 1. The "before" specimen, Fig. l(a), shows the basic twin structure of this material. Fig. l(b) shows the microstructure of the "after" specimen just below the fracture surface and reveals considerable cross-twinning as well as additional

Jan 1, 1970

By Shosei Serata

Serious floor heave of up to 2.4 m in a 2.4-m high mine entry was eliminated by applying the stress control method of mining, as a last resort, at the No. 5 coal mine of Jim Walter Resources, Inc., in the Black Warrior coal basin near Birmingham, Alabama. Underground observation of the first 3-room entry created using the stress control method is discussed here. The behavior of the test entry, which eliminated the heave problem, is analyzed in relation to similar studies conducted in a salt mine under similar ground conditions by utilizing finite element analysis.

Jan 1, 1984

By W. Rosotoker

Using an expression for the free energy of a homogeneous phase as a function of composition, a relationship is derived which interrelates the phase boundaries extending from the allotropic transformation of the solvent metal. Comparisons between observed and calculated phase boundaries in the systems Fe-Ni, Fe-Mn, Fe-W, Ti-Mo, and Ti-Cb are presented. IT is the purpose of this paper to illustrate how the general free energy equations for two phases in equilibrium may be used to derive an expression which interrelates the phase boundaries extending from the allotropic transformation of the solvent metal. The free energy per gram atom of a disordered solid solution may, for many purposes, be represented by the equation:' F = ½NZ [C-V,, + (1-C) VbB + 2C (l-C)V] + K(T) +RT[C-lnC+ (l-C)ln(l-C) ] [1] where N is Avogadro's number; Z, the coordination number; C, the concentration of the solute element in atomic percent; the subscripts refer to concentrations at phase mixture boundaries; VAA, VBB, and V,, are the bond energies between like and unlike adjacent atoms, respectively, at the interatomic spacing characteristic of the phase. The bond energies are usually assumed to be independent of small changes in the lattice parameter occasioned by solute additions and variations in temperature; V = VAB ---------------—— ; K(T) is the sum of the heat con- tent and heat entropy; R, the molar gas constant; and T, the temperature in degrees Kelvin. The free energy of a homogeneous phase is there- fore the sum of an internal energy, a specific heat, and a configurational entropy term, respectively. The compositions of two phases in equilibrium at a given temperature are governed by the minimum total free energy principle. Graphically, this is represented by the points of tangency of the tangent common to the free energy vs. concentration curves of the two phases. Analytically, this may be expressed as: ( df) = (df) [2] dc dc Expanding both sides using eq 1, the following equation is obtained after convenient readjustment of the terms: RT In[(ca)(1-c)]-½N (Vaa-Vbb)(Za-Zb) +NV [Za(l-2Ca)-Z,(l-2C,)] [3] The following assumptions have been made at this point: 1—The specific heats of the two phases are independent of composition variations within the range under consideration. Accordingly, the K(T) terms disappear on differentiation. 2— (Vaa)o = (VAA); (VBB). = (VBB); Va = V, Theyjustification for these assumptions can lie only in the successful application of the resultant equation. It may be noted that Zener2 has used assumption 1 in the calculation of the boundaries limiting the (a+j3) phase mixture in the Cu-Zn system.

Jan 1, 1952

LIST OF THE MEETINGS OF THE INSTITUTE AND THEIR LOCALITIES FROM ITS ORGANIZATION Transactions Number Place Date Vol Page 1 Wilkes-Barre, Pa May, ?71 1 3 2 Bethlehem, Pa August, ?71 1 10 3 Troy, N Y November, ?71 1 13 4 Philadelphia, Pa February, ?72 1 17 5 New York, N Y May, ?72 1 20 6 Pittsburg, Pa October, ?72 1 25 7 Boston, Mass February, ?73 1 28 8 Philadelphia, Pa May, ?73 2 3 9 Easton, Pa October, ?73 2 7 10 New York, N Y February, ?74 211 11 St Louis, Mo May, ?74 3 3 12 Hazleton, Pa October, ?74 3 8 13 New Haven, Conn February, ?75 3 15 14 Dover, N J May, ?75 4 3 15 Cleveland, 0 October, ?75 4 9 16 Washington, D C February, ?76 4 18 17 Philadelphia, Pat June, ?76, 5 3 18 Philadelphia, Pa October, ?76 5 9 19 New York, N Y February, ?77 5 27 20 Wilkes-Barre, Pa May, ?77 6 3 21 Amenia, N Y October, ?77 6 10 22 Philadelphia, Pa. May, ?78 6 18

Jan 1, 1923

By Cyril Wells, Robert F. Mehl

The two earlier papers in this series1,2 presented data on the rate of diffusion of carbon and of manganese in gamma iron. Apart from their scientific interest, these data are needed chiefly in order to treat data on carburization, on rate of formation of pearlite, and on rate of austenit-izing in a quantitative way.1'2'9'10 In the present investigation rates of diffusion of nickel in ?-Fe over wide temperature and concentration ranges have been determined, and the effects of carbon, of im- purities, and of grain size on these rates have been studied. Claussen,3 using the data of Fry,4 has calculated the diffusion coefficient of nickel in y-Fe as 9.2 X 10-11 sq. cm. per sec. at 1200ºC., but had no data from which to calculate the variation of D with concentration, temperature, and percentage of carbon. Method and Materials Method.—Nickel was diffused along the axis of a cylindrical specimen across a concentration gradient, concentration-penetration curves were determined and D values calculated from Grube or Matano solutions.5 Details of the method are given

Jan 1, 1941

By Cyril Wells, Robert F. Mehl

The two earlier papers in this series1,2 presented data on the rate of diffusion of carbon and of manganese in gamma iron. Apart from their scientific interest, these data are needed chiefly in order to treat data on carburization, on rate of formation of pearlite, and on rate of austenit-izing in a quantitative way.1'2'9'10 In the present investigation rates of diffusion of nickel in ?-Fe over wide temperature and concentration ranges have been determined, and the effects of carbon, of im- purities, and of grain size on these rates have been studied. Claussen,3 using the data of Fry,4 has calculated the diffusion coefficient of nickel in y-Fe as 9.2 X 10-11 sq. cm. per sec. at 1200ºC., but had no data from which to calculate the variation of D with concentration, temperature, and percentage of carbon. Method and Materials Method.—Nickel was diffused along the axis of a cylindrical specimen across a concentration gradient, concentration-penetration curves were determined and D values calculated from Grube or Matano solutions.5 Details of the method are given

Jan 1, 1941

By Peter R. Drummond

THE final casting of refined copper has been re-J- stricted for generations by the following sequence of operations: Filling the reverberatory furnace, melting, skimming, blowing or flapping, and poling. The hoped-for 24 hr cycle, producing 300 tons or more, has been taken up largely with the necessary bat time-consuming tasks of cleaning the bath, sulphur elimination, and in turn removal of excess oxygen to produce tough-pitch copper. Incidental to comparatively slow melting under combustion gases, copper oxides react with the furnace lining, and the slag so-formed must be completely recycled. The three-phase arc furnace has eliminated some of the cycle stages, and telescoped the remainder into a continuous operation. Electrical energy, supplied to graphite electrodes enclosed in high grade refractories, rapidly melts copper cathodes and sustains a stream of metal, containing approximately 0.01 pct oxygen, without contamination from fuel. The arc was struck on the first large electric furnace for melting copper in the United States on April 13, 1949. The earliest use of this type of furnace was at Copper Cliff, Ont., in 1936, and an admirable description of their installation has been published? Copper, melted in the Baltimore furnace, is used to cast billets, and the installation differs somewhat from the Canadian, as will be described. The arc furnace is a heavy-duty, three-phase furnace, holding 50 tons, the general outline of which appears on Fig. 1. The steel shell is 15 ft ID with a bottom radius of 14 ft 2 in. The roof, separate and distinct from the body, consists of a 15-ft water-cooled, cast-steel ring of the same outside diameter as the furnace. The center line of the furnace lies 9 ft 6 in. from that of the trunnions, permitting a 5" backward tilt for skimming, and a 40" maximum nose tilt forward for complete draining. Normally, the furnace overflows by displacement, and the use of the forward tilt arrangement is restricted to covering charging delays. The charging slot, 3 ft 8 in. x 5 in., lies on the north center line, the tap hole on the south, and the 30x30 in. skim door 45" to the west of the slot. The original 20-in. graphite electrodes were replaced with 14 in. in December 1949. Three conventional direct current winch drives, governed by electrical controls, position each electrode which has individual mast supports and counterweights. An independent circulation supplies cooling water for the electrode glands, the roof ring, charge slot, and the skim door frame. Arc Furnace Refractories Hearth: Fused-in monolithic bottoms had been used in copper arc furnaces, installed prior to April 1949. These consisted of thin layers of periclase, successively fused in place over preliminary brick courses. Heat was obtained from the arc, using a T-like arrangement of broken electrodes resting directly on the periclase to be fused. The operation, taking weeks to perform, was very expensive. The chemically-bonded magnesite-brick bottom, installed at Baltimore, was the first of its kind and a radical departure from previous practice. It consists of a 1 to 6-in. layer of castable refractory laid on the steel shell, modifying it to a 12 ft 2 in. bottom radius. Two courses of 9x2 % -in. fireclay straights and keys follow. The third course is made of 9-in. magnesite blocks of special shape to form circles of an inverted arch. It was started by a four piece keystone with skew-backs forming the outer course. The fourth course also started on a central keystone, or button, of four 90" segments, 12 in. diam x 13 Vz in. deep, and continued with 13%-in. blocks. Skewbacks at the shell completed the course to produce a horizontal surface for the side walls with a single course of No. 2 arch fireclay against the steel. Dry chrome-magnesite cement was brushed over each course after laying, and a 1-in. expansion space between the brick and the shell was filled with the same mixture. The total bottom thickness, excluding the castable material, was 5 in. of clay plus 22% in. of chemically-bonded magnesite. Tap Hole: A 5-in. OD and 3-in. ID silicon-carbide tube constitutes the tap hole and is set tangential to the upper course of the furnace bottom. Molten metal fills the tube when the furnace is level and filled to capacity. Side Walls: The lining, against the shell, consists of a 9x4Y2x3 in. soldier course of fireclay, using straights and No. 1 arches to turn the circles. A second soldier course of 9x4'/2x2'/2-in. fireclay was laid in a somewhat similar fashion. Three courses of 13Y2x6x3 in. and 9x6~3 in. of final magnesite, laid flat, completed the lining, using Nos. 1 and 2 keys to turn the circles. Cardboard spacers were placed between every two bricks in horizontal courses, and a thin coat of chrome-magnesite cement filled the joints between the firebrick and magnesite. A sprung-arch spanned the skim door with jambs of suitable magnesite shapes. Charge Slot: The slot is 3 ft 8 in. wide x 5 in. high. A silicon-carbide sill of special shapes has a 30" slope to allow cathodes to slide easily into the bath. The original arch was flat, and composed of Nos. 1 and 2 wedge magnesite with a 6-ft radius. It projected 5 in. over the sill, and, being a flat arch, gave an 18 15/16-in. opening between the inner edge and the metal line. The whole assembly was later raised 9 in., and the flat arch replaced with an arch, the lower edge of which maintained the 5-in, width from the outer to inner edges as shown in Fig. 2. A water-cooled, cast-copper jacket protects the steel shell behind the slot.

Jan 1, 1952

By S. R. B. Cooke, W. Philippoff, Donald E. Cadwell

[THE importance of contact angles in flotation has long been recognized, but little has been done to get quantitative relationships between the surface coverage of the mineral by the reagent, the length of the hydrocarbon chain, and the contact angle. It is well known that for a complete monolayer on the surface of a mineral the contact angle ? is determined only by the reagent&apos; and principally by the chain length of the hydrocarbon radical. Although for flotation the monolayer usually is regarded as being complete, early experiments of Wark and Cox2 showed that at very small concentrations of potassium ethyl xanthate the contact angle on galena changed in a continuous way from 0° to the equilibrium value of 60°. Further, Gaudin and Vincent&apos; showed a similar continuity using heptylic acid and sphalerite. This shows that with probably incomplete monolayers, ? varies with the degree of surface coverage. At the time these experiments were made it was impossible to measure the actual amount of surface coverage, especially since the decrease of the collector concentration in the liquor could be influenced by chemical side reactions. Through the use of the radioactive tracer method for the measurement of the amount of collector adsorbed on the surface of the mineral, Gaudin and Bloecher4 were able to determine accurately the actual surface coverage of dodecylamine acetate on quartz, but they did not measure any contact angles. It is believed that the relationship between the surface coverage and the contact angle is extremely important in flotation, especially as Gaudin and Bloecher showed that a 95 pct recovery is possible with a coverage of only 5 pct. Theoretical Considerations The work of adhesion W is the energy bound (in ergs per sq cm) when an interface is formed. It is determined by, the difference of the free surface energies (surface tensions) of the respective phases ?1 and ? 2 before contact and the interfacial free surface energy ?12 after contact. The definition of the contact angle permits the elimination of the unknown surface energy of the solid and hence the calculation5 of W from the surface tension of the liquid ? and the contact angle ?: [W = y (1 + cos ?)[1]] Consider a surface consisting of two components, identified as 2 and 3, 1 being the liquid. The amount of 2 in the composite surface is x, where 0 < x < 1. The respective contact angles with 1 and air are ? and ?3. The total work of adhesion of such a surface is the sum of the values of the components multiplied by their respective areas. A formal relation can be written: [W,,,=x•W2+ (1-x).WR[2] .] in which Wm is the work of adhesion of the composite surface. Eq 1 can be introduced into W2 and W3 but in the case of Wm some discussion is needed. If the two components are segregated, each component forming an integral part of the composite surface there is no physical meaning for a contact angle ?m, calculated from Wm, by using eq 1. If, on the other hand, the area of each patch of the components is small in comparison with, say, the diameter of the bubble used in measuring, it could be expected that ?m would have aphysical significance, because of the action of the surface tension of the liquid-gas interface tending to smooth out sharp corners. How small these patches would have to be is difficult to predict, but by using composite surfaces with microscopically]

Jan 1, 1952

By J. L. Workman

The Putnam Coal Mine, at design capacity, will be the third largest underground bituminous coal mine in the world and will feature the world&apos;s longest single flight belt conveyor. Construction is now in process; initial mining will commence in early 1969 and design capacity will be reached in 1971. The Putman Coal Mine reserves are located in south-central West Virginia and contain approximately 27,000 acres of prime Pittsburgh No. 8 coal; reserves are sufficient to support a 3.5 million tpy operation for over 30 years. The mine portal area is located some six miles inland from the Kanawha River. The river loading facility is located approximately 156 miles by way of river from the market.

Jan 1, 1969

Belting worth thousands of dollars can be ruined in a few minutes because of careless maintenance or lack of maintenance. Proper belt conveyor maintenance means having a clean conveyor system at all times. The belt line should be visually inspected during each shift. Equipped with proper maintenance instructions, one belt man can patrol a belt line of 2 to 3 km (1.5 to 2 miles). His duties would be to lubricate drives and idlers (except sealed-for- life type), maintain belt and conveyor frame alignment, detect sticking idlers, and maintain an unobstructed right-of-way.

Jan 3, 1978

By H. R. Peterson, G. J. Lipovetz, W. F. McDermott

One of the major improvements in ore grinding economics in North America has been the introduction of autogenous grinding. Pickands Mather & Co. has been active in the development of autogenous grinding since 1957. This early work led to the application of autogenous grinding to the Wabush mines ore in 1965, with the installation of six 24 ft diam by 8 ft long, 1750-hp mills. Development work recently completed in 1971 on another ore has led to the decision to install five 36 x 15-ft, 12,000-hp mills when this project goes ahead. Between these two decisions lies a tremendous amount of research, development and application of autogenous grinding to a variety of ores. The Pickands Mather Metallurgical and Research Laboratory in Hibbing, Minn., has tested ores from 9 different deposits in its pi- lot plant facility. Some of these deposits have as much difference within their own ore types as there is between the various deposits. Therefore, it is safe to say that over twenty different ore types have been tested and flowsheets developed for commercial applications. Of the nine projects, three are in operation. These are Wabush mines in Labrador, Canada,&apos; Savage River mines in Tasmania,&apos; and The Griffith mine in Red Lake, Ont., Canada.&apos;

Jan 11, 1972

By Sheldon P. Wimpfen

RESEARCH is undertaken to find out what must be done when what we are doing now is no longer adequate. To accomplish this end, researchers apply the truths of nature to industrial evolution. A survey conducted with the co-operation of 58 universities and colleges offering degrees in mineral engineering was the basis for the table accompanying this article. This survey was undertaken with the object of presenting to faculties and student bodies, as well as to industry, all available information on what action the educational institutions of the country have taken to provide the properly trained researchers so vitally needed. A hoped for result is that the great variety of opportunities available will encourage some undergraduate students to continue in their field beyond attainment of a B.S. degree.

Jan 1, 1947

NEW MEMBERS The following list comprises the names of those persons who became members during the period Nov. 10, 1916 to Dec.10, 1916. BARNSDALL, THEODORE N., Treas. & Mgr., Highland Gas Co., 24 West Corydon. St., Bradford, Pa. BEASLEY, FRED E., Asst. Supt., Copper Refinery, Consolidated Mining & Smelting Co., Trail, B. C., Canada., BREWSTER, THOMAS T., Vice Pres., Gen. Mgr., Mt. Olive & Staunton Coal CO., 1012 Federal Reserve Bldg.,-St. Louis, Mo. BRINDLE ARTHUR ST. C.... Mining Recorder&apos;s Office, Trout Lake, B. C., Canada. BULLOCK, Harry E., Pres Kentucky-Jewel Coal Co., Lothair, Ky. BUTLER, PERCY BENNETT, Mine Operator :..P. 0. Box 335, Joplin, Mo. BUTLER, ROBERT S Supt., Three Johns Mining CO., ,Joplin,.Mo. CABOT, Godfrey, L., Carbon Black Maker, Gas Engr., 940 Old South Building Boston Mass.

Jan 1, 1917

NEW MEMBERS The following list comprises the names of those persons who became members during the period Mar. 10, 1916 to Apr. 10, 1916. ALLEN, P. R., Pres., McAlester Coal & Coke Co., Knight Templar Bldg., McAlester, Okla. BERNARD, CLINTON PERCIVAL, Min. Engr., Care Forminiere Mission Kasai, Tschikapa, Congo Belge, W. Africa. CARPENTER, GEORGE 0., Vice-Pres National Lead Co. St. Louis Mo. CLARK, WILLIAM ANDREWS, JR., Min. Engr., Pres., Elm Orlu Mining Co., Butte, Mont. CLAYTON, CHARLES YANCEY, Asst. PrOf. of Metallurgy and Ore Dressing, Missouri School of Mines, Rolla, Mo. COHEN, JULIUS MILTON, Mgr. Croesus Gold Mines, Ltd., Matheson, Ont., Canada. CRAMER, WILLIAM BRONSON, Met. at Concentrator, Old Dominion Copper Min. & Smelt. Co., Globe, Ariz. DAHL, SIMEON H., Mill Supt., Messina Transvaal Dev. Co., Messina, Transvaal S. Africa.

Jan 5, 1916

By William F. Haddon, Phillip J. Maddex

Marco Polo brought the first borax to Europe late in the 13th century. It was especially treasured then for one of its many qualities-that of working with gold as a soldering flux. Georgius Agricola in 1556 gave it the name chrysocolla (which the Moors called borax)-literally, "gold glue." Deposits of borax have been elusive and widely scattered-first found only in Tibet and Italy, and, in 1836, at Iquiqui, Chile. Dr. John Veatch made the first California discovery in 1856 while examining a mineral spring east of Red Bluff. This "Borax Lake" soon supplied 90% of U.S. demand, but flooding and other production problems caused the scene to shift from Borax Lake to Little Borax Lake and then to Nevada in 1871. Early transportation was by "Twenty-Mule Teams."

Jan 1, 1971