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By Clement K. Chase

ION exchange recovery of uranium has been proved successful in many operating plants in various parts of the world. First used in column plants processing clear liquors, ion exchange has more recently been applied in basket resin-in-pulp systems. A logical further development is the application of truly continuous processing techniques to the ion exchange recovery of metals, since previous systems have been semicontinuous at best. Column ion exchange is a valuable technique and has been used extensively in South Africa and elsewhere. However, it requires clear liquors. To produce these clear liquors, considerable investment in filter plant and clarification equipment is necessary. In the cases where it is very difficult or impossible to produce clarified liquors, column ion exchange is not so useful. Moreover, some liquors suffer from post-precipitation after clarification, which can become a serious problem.

Jan 9, 1957

By George L. Lyle

WITH the advent of World War II, the need for agricultural products rose phenomenally and caused a similar increase in demand for plant foods of which phosphate rock is one of the more important raw materials. By the close of the war or shortly thereafter, all of the operating companies were expanding their production facilities. Many companies installed modern bulk material handling facilities. Designs varied, but were generally of the overhead trestle type of storing conveyors. American Cyanamid studied these various installations but was not satisfied with the conventional system because of high initial cost, increased maintenance problems in the way of painting structural steel that might be submerged in stored materials, and because of slightly increased operating costs. As a consequence of these economic analyses, conferences were held with the various conveyor manufacturers to develop a better method of storing and reclaiming. After considerable engineering study, one conveyor manufacturer suggested the unique system which was installed in 1950.

Jan 8, 1954

By P. W. Harben

Jan 1, 1985

By H. E. Lee, P. C. Feddersen

Blast-fuRnace operation at the Bunker Hill smelter deviates somewhat from common practice. Under existing conditions it is economical to operate the furnaces at "forced" capacity. The furnace feed consists chiefly of sinter and averages close to 50 per cent lead. Experience in smelting such material favors a low charge column attended by smaller proportions of coke and a low blast pressure. Under such conditions the gain in furnace tonnage greatly overbalances the somewhat higher slag losses and increased percentage of material fumed Furnace Charge The ingredients for the blast-furnace feed are stored in a group of 24 charge bins (3600 cu. ft. capacity). Each bin has two discharge chutes. Beneath each chute is a steel weighing hopper, suspended from a Fairbanks scale. The several hoppers are kept filled with the exact amount of material required to complete a furnace charge. The weighed material is discharged into a standard-gauge, bottom-dump charge car containing two compartments, each of which holds a complete charge (approximately 1½ tons). It is hauled to the blast furnace by a 44011 electric trolley locomotive. The proportionate parts of the various constituents of a representative blast-furnace charge are shown in Table 1. Table 1.—Representative Blast-furnace Charge at Bunker Hill Smelter Material Pounds Sinter.................................................. 2500 Limerock............................................... 0- 50 Coke................................................. 250-300 Scrap iron.............................................. 0-25 Settler skulls.......................................... 75 Undried zinc-plant residue................................ 0-200 Siliceous ore............................................ 25 Baghouse dust.......................................... 0-50 By-product slag......................................... 100 A variable stock tonnage of zinc-plant residue and return by-products results in fluctuations in the percentages of these materials in the blastfurnace feed. Accompanying such variations are corresponding increases or decreases in the amounts of coke, limerock and scrap iron necessary to obtain good furnace operation and adequate reduction.

Jan 1, 1937

By M. F. Williams, L. G. Hendrickson

In classification of pulps bearing magnetized ferro-magnetic particles, depolarizing is of great importance. If size separation is to be effective, particles must be individual rather than in flocs. Depolarizing is also practiced in heavy medium separations in which ferrosilicon or magnetite is the medium. When particles of ferromagnetic material have been removed from a magnetic field, residual magnetism causes agglomeration. The term depolarizing refers to the operation of reducing or eliminating this residual magnetism and may thus be considered magnetic deflocculation. The terms demagnetizing and randomizing are also used.

Feb 1, 1956

By R. A. Vandermeer, J. C. Ogle

The preferred crystallographic orientations (texture) developed in randomly oriented, poly crystalline niobium during rolling were studied by means of X-ray diflraction techniques. The evolution of texture at both the surface and center regions of the rolled strip was carefully examined as a function of increasing defamation throughout the range 43 to 99.5 pct reduction in thickness. Certain aspects of the center texture development in niobium are in agreement with the predictions of a theory by Dillamore and Roberts, but others cannot be explained by the theory in its present form. Above 87 pct reduction by rolling, a distinctly different texture appeared in the surface layers which was unlike the center texture. The present results are compared with previous results obtained from other bcc metals and alloys. RANDOMLY oriented, poly crystalline metal aggregates when plastically deformed to a sufficiently large extent develop preferred orientations or textures. In a recent review article, Dillamore and Roberts1 pointed out that the nature of the developed texture may be influenced by a large number of variables. These include both material variables such as crystal structure and composition and treatment variables such as stress system, amount of deformation, deformation temperature, strain rate, prior thermal-mechanical history, and so forth. From a practical point of view, the control of preferred orientation may often be important for the successful fabrication of metals into usable components. During the past few decades many experiments have been devoted to the study of deformation textures. This work, however, has been confined in large part to metals and alloys that have an fcc crystal lattice. By comparison, bcc metals and alloys have received much less attention, and consequently our understanding of preferred orientations in these materials is only shallow. This state of affairs worsens when it is realized that almost all of our present howledge about this class of materials derives from studies on irons and steels.' The bcc refractory metals, which are relative newcomers to the industrial world, have, on the other hand, been given at best only passing glances in the area of texture development. Our understanding of the evolution of preferred orientations in bcc metals can only remain fairly limited until systematic studies of metals and alloys other than the irons and steels have been carried out and the influence of the many variables has been determined. To that end a program was initiated to investigate in detail texture development in niobium. The present paper reports some of the results of this study. Textures were determined at both the center and surface of strips rolled variously to as much as 99.5 pct reduction in thickness at subzero temperatures. Emphasis in this paper is on texture description and on texture evolution during rolling to progressively heavier deformation. EXPERIMENTAL PROCEDURE The niobium was purchased from the Wah Chang Corp. as a 3-in.-diam electron-beam-melted billet. Chemical analysis indicated the impurities to be less than 300 ppm Ta, 40 ppm C, 10 ppm H, 170 ppm 0, and 110 ppm N. All other impurities were below the limits of detection by spectrochemical analysis. This large-grained billet was fabricated into specimen stock so that a fine-grained randomly oriented grain structure resulted. This was accomplished in three deformation steps alternated with recrystalli-zation anneals of 1 hr at 1200°C in a vacuum of low 10"6 Torr range after each deformation step. The first step was to alternately compress the billet 10 to 20 pct in each of three orthogonal directions. The second step was to compress in only two directions 90 deg apart to produce a 2-in.-sq bar. The final step was to roll this bar 50 pct to give a 1-in. by 2-in. cross section. After the final anneal, metallo-graphic examination showed the material to have an average grain size equivalent to ASTM No. 5 at 100 times (i.e., 0.065 in. diam). Specimens cut from the center and edges of this bar gave no indication of detectable preferred orientation when examined by X-ray diffraction. Samples 1.5 in. long, either 0.625 or 0.750 in. wide, and approximately 0.400 in. thick were machined from this fabricated ingot. The surfaces corresponding to the rolling planes were ground so as to be parallel. The samples were chemically polished in a solution of 60 pct nitric acid and 40 pct hydrofluoric acid (48 pct solution) prior to rolling to remove any cold work introduced in the machining operations. Rolling was accomplished with a 2-high hand-operated laboratory rolling mill that had 2.72-in.-diam rolls. Prior to operation, the rolls were polished with 600 grit paper, cleaned with acetone, and then soaked in a container of liquid nitrogen for several hours. The samples were also soaked in liquid nitrogen prior to rolling and were recooled between each pass. While some slight heating of the samples occurred during rolling, this procedure maintained the sample temperature well below 0°C at all times. The samples were rolled unidirectionally, and the rolling plane surfaces were not inverted during any phase of the operation. The draft per pass averaged between 0.010 to 0.012 in. After 96 or 97 pct reduction the draft was reduced to 0.001 to 0.002 in. per pass. Samples were rolled to various reductions in thickness between 43 and 99.5 pct.

Jan 1, 1969

By R. N. Kust, J. C. Agarwal, H. E. Barner, N. Beecher, D. S. Davies

Kennecott Copper Corp. has developed a new hydro-metallurgical process for extracting nickel, copper, cobalt and molybdenum from manganese nodules. This process (KCC Cuprion Process) utilizes a reduction leach operating at atmospheric pressure in the temperature range of 45°C to 50°C and has been successfully demonstrated in a continuous Pilot plant processing 350 kg/d of nodule ore. The chemistry, basic flowsheet and operating characteristics are presented and discussed.

Jan 12, 1979

By G. H. K. Schenck, H. W. Robinson

Private weather forecasting services available on a contract basis can significantly reduce the uncertainty associated with weather-induced changes in mineral production and demand. Such services offer the mineral producer the opportunity for tactical and strategic response to weather conditions. There are at least 50 private meteorological consulting services as well as numerous individual meteorology consultants. Fees for services range from $150-$600 per day for one man to over $20,000 per month where a complex forecasting or modification program is undertaken.

Jan 1, 1971

By D. M. Deason, R. M. Chhatre, G. Y. Onoda

INTRODUCTION The treatment of colloidal suspensions is a subject of increasing interest in mining and benefication (1). Colloidal suspensions are not readily operated upon by mechanical and physical methods useful with coarse suspensions, such as filtration, thickening, and flotation. This is because colloids are strongly affected by interfacial and interparticle forces that may be large compared with, and resistant to, external forces. The degree and type of interactions between colloids can be modified by small additions of reagents such as coagulants, flocculants, dispersants, and immiscible liquids. These alterations in turn change the properties of the suspension and provide possible opportunities for transforming suspensions to a more favorable condition for a given processing operation. Phosphate slimes are an example of a colloidal system of interest today. In the mining and beneficiation of phosphate rock in Florida, slimes are a waste product. The phosphate ore (called matrix in the industry) is slurrified hydraulically and pumped to a beneficiation plant, where the -150 mesh material is removed by cycloning from the coarser phosphate rock and silica. The resulting -150 mesh slurry, called phosphate slime, is pumped to large impoundments. The solid content of the slime entering the impoundment is around four weight percent, and over 80% of the solids is less than one micron in size. The immediate problems with phosphate slime relate to their disposal (2, 3). The disposal problem is associated with the very large volumes and the poor dewatering characteristics of the slimes. To have sufficient impoundment volume, large earthen dams are built around the mined areas. The volume above ground level approaches and

Jan 1, 1980

By High Archbald

It is possible to construct a simple diagram of the earnings, or the production, of the men employed at a coal mine that will show not only if the conditions tend toward contentment among the men, but if the operating distribution of the work is correct. As earnings are the greatest cause of discontent, even exceeding all the other causes, if contentment exists in the matter of earnings, the likelihood of other discontents flaring up is greatly lessened. The basis of such a diagram would be the Gaussian curve of the normal variation in human ability. Such a curve has long been recognized. H. L. Moore,' in discussing the quantitative relation between wages and ability says: "It has been pointed out that industrial efficiency is dependent upon physical, mental, and moral qualities, and these qualities . . . there is good reason for regarding as being distributed according to the Gaussian law.

Jan 1, 1925

By Philip L. Collyer

A technique for evaluating the similarity of ore deposits is presented. A Q-mode cluster analysis is performed using information on tungsten mines in North America. This is a method of grouping several samples according to their similarity based on a simple matching coefficient. Tungsten mines are grouped or clustered on the basis of geologic variables. It is possible to interpret and evaluate different ore environments according to age, mineralogy, and other variables. It is well known that variable geologic conditions influence the occurrence of certain types of minerals. If one variable is responsible and identified, that variable can be searched for in exploration. If several interrelated variables are responsible for forming a favorable environment, then recognition and identification may be more difficult or completely masked. Therefore it is helpful in exporation to isolate and identify multiple interrelated variables which control the localization of mineral deposits. Cluster analysis is useful in mineral exploration where considerable amounts of data are available for analysis. Subtle relationships that might be overlooked because the data are voluminous can be isolated using this technique. Cluster analysis can be used to establish exploration prioriy in unknown areas on the basis of similarities to known metallogenetic provinces.

Jan 1, 1976

FRIENDS of the late Charles F. Rand presented in 1930 a sum of money from which the income is available to support various phases of the work of the Institute in which Mr. Rand was so deeply interested. At present the fund amounts to $10,000. The specific terms of the deed of gift are as follows: "The fund collected to establish a memorial to the late Charles F. Rand shall be placed in the custody of the Board of Directors of the American Institute of Mining and Metallurgical Engineers, to be set up as a trust to be known as the `Charles F. Rand Foundation,' the income of which shall each year be applied to a distinct purpose to be decided upon in that year by vote of the Board of Directors. This purpose shall be such as to promote the general welfare of the Institute and to constitute a permanent memorial of the usefulness of Mr. Rand, who for many years gave unstintingly of his time and talents in its service.

Jan 1, 1946

By H. W. Dow

Quite early in the beginning of the present century, hoisting equipment underwent a radical change, when electric motors were applied to furnish the power in place of steam engines. Naturally, in the beginning, motors were not employed for large hoists: most of them were small single-drum hoists for which the motor ran continuously and the drum was clutched in for hoisting by various methods, and the down-going trips were made on the brake. In 1911 the Nordberg Manufacturing Co. of Milwaukee built for the first time a double-drum hoist powered with a first-motion direct-current motor (Fig. I). This hoist embodied many of the features that are used on larger hoists today. In the early development of motor-driven hoists a more or less natural mis- take was generally made, which only recently is being corrected. Because the electric motor has a higher speed than the steam engine, mining people in general accepted, without question, the use of small-diameter drums and the resultant finding of the rope in multiple layers, which was not at that time, the general practice on first-motion steam hoists. Small-diameter drums can usually be driven by a motor through a single reduction of gears even with relatively high motor speed, therefore the complete equipment could be obtained with a lower first cost.

Jan 1, 1946

By Fred C. Bond

DISCUSSION Milton C. Shaw and Donald R. Walker (Massachusetts Institute of Technology)—For many years the two empirical rules of comminution bearing the names of Rittinger and Kick have been applied to grinding processes to account for the energy required to crush brittle materials. The basis for Rittinger's rule was the thought that the energy to grind a substance went largely into supplying the additional energy associated with the new free surface, while Kick's law was prompted by the concept of dimensional similarity and is a special statement of the concept of constancy of strain energy to cause rupture. According to Rittinger the energy to grind a given volume varies as the change in the square of the mean particle size, v - A (D2), while according to Kick this energy varies

Jan 1, 1953

By Fred C. Bond

DISCUSSION Milton C. Shaw and Donald R. Walker (Massachusetts Institute of Technology)—For many years the two empirical rules of comminution bearing the names of Rittinger and Kick have been applied to grinding processes to account for the energy required to crush brittle materials. The basis for Rittinger's rule was the thought that the energy to grind a substance went largely into supplying the additional energy associated with the new free surface, while Kick's law was prompted by the concept of dimensional similarity and is a special statement of the concept of constancy of strain energy to cause rupture. According to Rittinger the energy to grind a given volume varies as the change in the square of the mean particle size, v - A (D2), while according to Kick this energy varies

Jan 1, 1953

By R. B. Kelly, Paul Martin

Central Texas added 76 producing oil and gas wells during the year, abandoned 378 wells in the same period, and produced 10,359,905 bbl. of oil in the 12 months under consideration. The oil production represents a decline of only 3 per cent as compared to 1934, but it must be remembered that much new production was added during the year. The activity in new work centered in Frio, Bexar, Williamson and Cald-well counties, with development in the Pearsall, Von Ormy and Byersville fields taking first importance. New discoveries in 1935 were confined to Pearsall area of Frio County and an extension to the Darst Creek field in Guadalupe County. The Red Lake field, in eastern Freestone County, proved itself of importance from the standpoint of a gas reserve but no oil production has yet been obtained. In Bexar County, the Von Ormy field, in which the discovery well was drilled early in 1934, completed 22 oil producers during the year. (A map of Central Texas showing location of oil and gas fields was published in Volume 114 of the A.I.M.E. Transactions.) New Fields Pearsal1.—The Amerada Petroleum Corporation, in developing its 60,000-acre block in Frio County, has definitely proved the existence of commercial oil production in four separate horizons; namely, the Navarro, the Austin Chalk, the Buda and the Georgetown. The discovery well, a two million cubic foot gas well, was tompleted in 1934. A test of the Trinity sand at 10,050 ft. found salt water but later was plugged back and finished as an oil well in the Navarro sand. Most recent of their discoveries has been in the Austin Chalk at a depth of 5666 ft., where a 24-hr. gage through 1-in. choke showed 2640 bbl. of pipe line oil. The oil has a gravity of 28.0" A.P.I. and is brownish in color. Because of lack of pipe lines in the area, the wells are produced only for short periods of time, and it is predicted that development will be slow until the district is entered by pipe line purchasing companies. Von Ormy.—In March, 1934, Umbren et al. completed their Wentz

Jan 1, 1936

By Paul Martin, R. B. Kelly

Central Texas added 76 producing oil and gas wells during the year, abandoned 378 wells in the same period, and produced 10,359,905 bbl. of oil in the 12 months under consideration. The oil production represents a decline of only 3 per cent as compared to 1934, but it must be remembered that much new production was added during the year. The activity in new work centered in Frio, Bexar, Williamson and Cald-well counties, with development in the Pearsall, Von Ormy and Byersville fields taking first importance. New discoveries in 1935 were confined to Pearsall area of Frio County and an extension to the Darst Creek field in Guadalupe County. The Red Lake field, in eastern Freestone County, proved itself of importance from the standpoint of a gas reserve but no oil production has yet been obtained. In Bexar County, the Von Ormy field, in which the discovery well was drilled early in 1934, completed 22 oil producers during the year. (A map of Central Texas showing location of oil and gas fields was published in Volume 114 of the A.I.M.E. Transactions.) New Fields Pearsal1.—The Amerada Petroleum Corporation, in developing its 60,000-acre block in Frio County, has definitely proved the existence of commercial oil production in four separate horizons; namely, the Navarro, the Austin Chalk, the Buda and the Georgetown. The discovery well, a two million cubic foot gas well, was tompleted in 1934. A test of the Trinity sand at 10,050 ft. found salt water but later was plugged back and finished as an oil well in the Navarro sand. Most recent of their discoveries has been in the Austin Chalk at a depth of 5666 ft., where a 24-hr. gage through 1-in. choke showed 2640 bbl. of pipe line oil. The oil has a gravity of 28.0" A.P.I. and is brownish in color. Because of lack of pipe lines in the area, the wells are produced only for short periods of time, and it is predicted that development will be slow until the district is entered by pipe line purchasing companies. Von Ormy.—In March, 1934, Umbren et al. completed their Wentz

Jan 1, 1936

By L. B. Ticknor, M. B. Bever

An isothermal calorimeter suitable for measurements of heats of solution in liquid tin as solvent is described. Measurements of the heats of solution of gold, silver, copper, and a gold-silver alloy are reported. The heat of formation of this gold-silver alloy is also reported. HEATS of solution in liquids can be determined directly, but few such data have been published for metals as solvents. Knowledge of heats of solution is desirable because it contributes to the general understanding of energy relations in metallic solutions. Thermochemical measurements of this type also furnish answers to specific problems: For example, from the heats of solution of an alloy and of a mixture of its constituent elements in a given solvent, the heat of formation of the alloy may be found. Similarly, differences in the energy content of samples of the same metal in two different states, such as the annealed and cold worked states, may be determined. In the work reported here, gold, silver, and an alloy of gold and silver were dissolved in liquid tin at 240°C and gold, silver, and copper were dissolved in tin at 300 °C. The experiments yielded the heats of solution of these metals in tin. The heat of formation of the gold-silver alloy was also determined. The same calorimetric method is being used to measure the energy stored in metals during cold working and preliminary results have been published.' Equipment and Experimental Procedure The isothermal calorimeter used in this work, Fig. 1, consisted of a Dewar flask completely immersed in a constant-temperature salt bath. A long neck provided space for thermocouple leads and a stirrer shaft and permitted the injection of solute samples. The metal bath in the calorimeter flask was stirred at about 100 rpm by a small glass impeller driven by a constant-speed motor. The shaft of the stirrer passed through a Wilson vacuum seal.2 All measurements were made under vacuum in order to eliminate temperature disturbances resulting from gas convection and to prevent the oxidation of tin. The calorimeter flask was joined by an all-glass connecting line to a gas-control system which made possible the use of a protective atmosphere of deoxidized and dried hydrogen. At the operating temperature of the calorimeter tin oxide was not reduced by hydrogen, presumably because the reaction rate was too slow. Part of the closed system was a removable side tube through which the solute sample could be introduced and in which it was held at a temperature of 0°C prior to injection into the metal bath. The salt bath containing a mixture of sodium, lithium, and potassium nitrates was similar to that described by Beattie3 and was equipped with a stir-

Jan 1, 1953

By R. A. Wood, R. I. Jaffee, H. R. Ogden, D. N. Williams

Dispersion-containing titanium-copper alloys were prepared having mean free paths varying from 1.0 to 9.7 P. Tensile studies at room temperature and at 1000°F showed that little or no strengthening occurred when the mean free path exceeded 3 p. However, at lower values of mean free path appreczable strengthening was observed. A considerable amount of strengthening also resulted from copper in solid solution. DURING the past several years, an increasing amount of study has been devoted to dispersion hardening, an alloying process in which increased strength is obtained through the addition of a ran-

Jan 1, 1961

By Robert H. Richards

Very little has been published recently on this subject in the mining journals or proceedings of societies. The attention of experts has been diverted perhaps by the demands for pan amalgamation of refractory ores. Yet free milling ores occur in many localities, and it may be interesting to have on record some data as to details of running a small test-mill, especially as details of results do not seem to be accessible to stndents and investigators. Küstel, in 1863, under battery amalgamation, dismisses the subject by stating that "amalgamation on copper-plated platforms, troughs, and other copper fixings" is " very imperfect, and mostly abandoned." J. Arthur Phillips says, in 1867, under placer mining : " A well-amalgamated copper plate is considered as effective for

Jan 1, 1880