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By Don Masson

MUCH has been written and many prophecies made on the subject of plastics as a replacement for metal, and the extent to which these materials will compete with each other for peace- time markets. (Metal is used in a broad sense to include all types.) But although certain synthetic resin materials have made considerable headway in war production, this change to plastics can hardly be regarded as a serious threat to the mining and metallurgical industries. Even today, the total yearly tonnage of plastic materials is approximately only 1 per cent of that of steel, and only a small fraction of this might be considered as actually replacing steel. However, these figures must not be taken as indicating that the importance of plastics in fields hitherto considered exclusively the territory of metals is negligible-far from it. Considering the comparatively minute tonnage of plastics now being produced in comparison to the output of metals, the number of applications where plastics have augmented or aided the sale of metals is considerable.

Jan 1, 1944

THE Institute of Metals Division of the A. I. M. E. has joined with the American Society for Steel Treating and the American Welding Society in support of National Metal Week in Philadelphia, Oct. 8 to 12. Individual and joint technical sessions, plant inspection trips, and a general exposition to be held in Commercial Museum have all been arranged. With the coming of the Institute of Metals Division into the circle, the scope of the exposition has been broadened to cover non-ferrous metals, and exhibits of much interest are promised. Headquarters for the Institute of Metals and the American Society for Steel Treating will be at the Benjamin Franklin Hotel, and for the American Welding Society at the Bellevue-Stratford. The American Society for Steel Treating and the Welding Society will hold technical sessions each forenoon at their hotel headquarters. The Institute of Metals Division will hold sessions Tuesday morning and Wednesday and Thursday afternoons; that for Wednesday being a joint session with the American Society for Steel Treating. The latter society will hold independent afternoon sessions on Thursday and Friday. Registration and information desks will be open at the hotels throughout the week, and an attractive program of entertainments has been arranged.

Jan 1, 1928

By Wm. A. Haven

As soon as the likelihood of American participation in the war was established, and in spite of the fact that we can produce almost as much as all other countries combined, the demand for prompt deliveries of iron and steel products from American factories began to exceed their utmost capacity, and, after fifteen months of practically full operation, has continued to do so. Therefore, it would seem worth while to review some of the aspects of the supply and demand for steel as well as the efforts that are being made to bring them into balance. It is still being debated as to whether the situation should be defined as a real shortage that will persist through the emergency period or as a temporary one than can be relieved by less drastic measures than a Government-sponsored program of expanding existing plants and building new ones.

Jan 1, 1942

By Donald C. Myntti

INTRODUCTION A major segment in a successful heavy equipment maintenance and repair program is the provision of well-laid out and well-equipped shop and service facilities The facilities described here will be those required for a large, high tonnage hard rock open pit mine utilizing rotary drills, shovels, haulage trucks, support equipment, and service trucks. The term support equipment covers the equipment required to support the drill, shovel, and truck operations, these are crawler tractors, road graders, front-end loaders, water trucks, rollers, rubber-tired tractors, etc. Service trucks are the automotive type consisting of rubber-tired over-the- road equipment. The primary structures generally involved in the total maintenance effort are as follows. (1) the main shop with an attached warehouse (the structure could also house the tire and lube shops plus the equipment cleaning stalls), (2) a service station with bulk petroleum product storage tanks, (3) a heating plant, (4) a security station (lf this is a corporate requirement), (5) operating department and employee assembly buildings, and (6) an electrical substation. Under certain conditions, many of these facilities with the exception of the substation could be combined In one or several structures. This arrangement could have a great advantage especially in areas where the heating of the structures is extremely critical.

Jan 1, 1979

By AIME AIME

PRACTICALLY all the Section delegates as well as a sprinkling of Institute officers and mere members were on hand for the annual business meeting of the Institute on Monday afternoon of the Annual Meeting. President McAuliffe presided, with C. H. Mathewson as associate chairman. Americo Albala was first called on to discuss the work of the Pan American Institute of Mining Engineering and Geology. C. Will Wright said that the need for such an organization was evident, and a resolution was passed asking the incoming President to appoint a committee to investigate cooperation with that body, of which Mr. Albala is executive secretary.

Jan 1, 1943

By J. H. Brophy, S. J. Michalik

A constitution diagram for the system Mo-Ir has been determined. The maximum solubility of iridium in molybdenum is 16 at. pct at 2110ºC and decreases to less than 5 at. pct at 1500°C. The solubility of molybdenum in iridium is 22 at. pct. Three intermediate phases appear in the system: 8 MoJr, having the p-tungsten structure; a phase, a cornplex tetragonal structure; and the hcp ? phase. Metallography, melting point determinations, X-ray diffraction and fluorescence, and electron micro-probe unalyses were employed in establishing the diagram. PREVIOUS to the present investigation, the intermediate phases in the Mo-Ir system were identified, but no detailed account of the phase diagram has been reported in the literature. Raub1 investigated alloys of Mo-Ir over an extensive range of composition between the temperatures of 800º and 1600°C. The in-termetallic compound MosIr was found to exist with nearly pure molybdenum, as the solubility of iridium in molybdenum was not detectable parametrically in this temperature range. MO3Ir was found to be iso-morphic with a ß-tungsten type structure, having a parameter of 4.959Å. An intermediate hcp phase, designated as the ? phase, ranged in composition from 52 to 78.5 at. pct at 800ºC, and from 41 to 78.5 at. pct Ir at 1200°C. Parameters noted for the ? phase were as follows: at 42.7 at. pct Ir, a = 2.771i0, c = 4.4366, c/a = 1.601; at 78.5 at. pct Ir, a = 2.736A, c = 4.378A, c/a = 1.600. Molybdenum was found to be soluble in iridium up to 16.5 at. pct Mo (83.5 at. pct Irj, with the parameter of iridium increasing to 3.845A at the solubility limit. Knapton,2 who investigated alloys between 15 and 85 at. pct Ir, essentially agreed with Raub's data, but, in addition, found a a phase in as-melted alloys near 25 at. pcto Ir. The oaphase lattice parameters were a = 9.64Å, c = 4.96Å, c/a = 0.515. The a phase was replaced by the 8 -tungsten phase on annealing at 1600°C. Knapton concluded that the a was stable only at elevated temperatures, and placed the composition of the a phase at approximately 30 at. pct Ir. The intermetallic compound Mo3Ir, with a lattice parameter of 4.965A, was included among the 8-tungsten structures reported by ~eller.' Matthias and Corenzwit,4 and Bucke15 studied the superconducting nature of MosIr, and reported a superconducting transition temperature of 8.$K. The present investigation describes the phase relationships in the Mo-Ir alloy system determined by melting point measurements, X-ray diffraction and fluorescence, and metallography. EXPERIMENTAL PROCEDURES Alloys for the determination of the phase diagram were prepared from powders. Commercial 99.9 pct Mo from Fansteel Metallurgical Corp. and 99.9 pct Ir powder from J. Bishop and Co. Platinum Works were used. The powders were weighed to nominal compositions, mixed, and then pressed, without binder, into compacts weighing 4 to 6 g. These were presintered in uacuo between 1200' and 1400°C for 1 hr, to reduce the degree of spattering during subsequent arc-melting. The compacts were arc-melted in a nonconsumable tungsten electrode furnace six times on alternate sides on a water-cooled copper hearth in an atmosphere of zirconium-getter ed argon at 500 mm of mercury pressure. In almost all cases, this procedure yielded buttons of satisfactory homogeneity. The composition of all melted buttons were confirmed by X-ray fluorescent analysis using the experimentally determined ratio of the iridium La1 line intensity to that of the molybdenum Ka1 line as a function of composition. In this determination four alloys analyzed by wet chemical methods were used as standards. An uncertainty range of ±1 at. pct has been attributed to all indicated compositions. All heat treatments and solidus measurements were carried out in tantalum resistance heating elements in vacuum conditions of 10-4 to 10-5 mm of mercury. A detailed account of this procedure has been reported by Schwarzkopf and Brophy.8 In the heat treatment and solidus measurements of iridium-rich alloys (50 at. pct Ir or greater), a tungsten lining was inserted into the tantalum resistance heating element because of a eutectic reaction which occurs between iridium and tantalum at 1948ºc.7 Heat treatments and solidus measurements carried out at compositions less than 40 at. pct Ir both with and without tungsten linings within the resistance

Jan 1, 1963

By T. I. Moore, L. A. Painter

THE electrolytic zinc plant of the American Zinc Co. of Illinois was described by Davidson' in 1944. Since then, improvements as well as expansion of the plant facilities have been made. In order to increase the production of high grade zinc which was needed for war purposes, an expansion program designed to double the slab zinc capacity was started in 1942 and completed in March 1943. This expansion was propagated by a contract between the American Zinc Co. of Ill. and the Defense Plant Corp. The contract included the facilities of the Fairmont City, Ill., property of the American Zinc Co., where a suspension-type roaster with contact acid plant, cadmium distillation furnace, Waelz oxide and densifying plant, and horizontal retort furnaces were installed. The expanded Monsanto, Ill., plant and the additional facilities of' the Fairmont plant were designed to integrate the metallurgical treatment of zinc concentrates for the production of special high grade zinc at Monsanto with the production of acid, cadmium, high grade zinc from furnace skimmings and the Waelz treatment of leach residue at Fairmont. In general, the original flowsheet was not changed, except for the addition of the filtering, drying and reclaiming of leach residue, and the treatment of purification cake for the recovery of copper, cadmium sponge, and zinc. Fig. 1 is a flow diagram of present operations. The original plant facilities, desi-gned for 50 tons daily production of slab zinc, had some units which were more than adequate. Therefore, in expanding the facilities to 100 tons per day, it was not necessary to double all operating components. Table I gives the comparison of the changes made in the unit operating components for the original facilities, 1941, the 1943 expansion, and the 1951 facilities. During the past 11 years a number of improvenients have been made resulting in: 1—an increase in slab production, 2—higher recoveries on the calcine treated, 3—better quality of slab zinc produced, 4—higher current efficiencies, and 5—less man hours Table I. Changes in Operating Facilities Operating Unit 1941 1943 1951 Calcine unloading (pneumatic), 10 tons per hr 12 calcine unloading track hpr. and elev., 60 tons per hr 1 Calcine storage, tons 1,000 2,000 2,000 Leach tanks, 35 vol. tons. No. 3 5 6 slurry mixing 6x6 ft stainless tank, No. 1 Ball mill. 4.5 rt x 16 in. conical. No. 1 CLassifier duplex, No. 1 1 Thickeners. 50 it diam. No. 2 9 2 Filter thickeners, sq ft '-- Moore filters, sq ft 5.760 11,520 Drum filters, 10 ft diam x 16 ft, No. 3 3 Rotary arlers, No. 1 2 1st stage Cu-As purificatlon tank. 90 vol. tons, No. 3 Solution heaters, No. 3 Filter press, 30x30 bronze, No. 4 Zinc dust purification tanks, 45 vol tons. No. 3 5 4 Filter press, 36x36 bronze, No. 3 5 3 Cadmium recovery plant: Process tank. No. 5 2 Cake roaster, 20 ft diam x 4 hearth. No. 1 Filter press, 24x24, No. 4 1 Sponge wash box, 4x6 ft, No. 1 Evaporative cooling unit (vacuum), No. 1 Purified storage tank, vol. tons 400 400 400 Cell acid storage, vol. tons 400 400 400 Electrolytic cells, No. 180 372 372 Cell room ventilation, cu ft per min 35,000 125,000 125,000 Cell cooling water. gal per min 1,500 2,300 2,300 Deep well 16 in. x 95 ft, 1500 gal per min, No. 2 3 3 Melting and casting furnace, 130 ton. No. I Furnace fume scrubber unit, No. 1 Dross drums, No. 2 Dross roaster, 8 ft diam x 8 hearth, No. 1 Electrolysis power conversion, kw 6,250 23,750 23,750 Power transformers, 13,800/440, kva 1,000 1,500 2,000 Steam boilers fire tube, 15 psi, lb per hr 12,000 18,000 18,000 Steam boilers water tube. 125 psi, Ib per hr 30,000 Air compressor, 2 stage. 300 cu ft per min. 100 psi, No. 1 2 Air compressor, 1 stage, 300 cu ft per min, 20 psi, No. 1 Vacuum pumps, 18x7, 720 cu ft per day, No. - - . Vacuum pumps, 24x11, 1.633 cu ft per day, No. 3 3 Building area, sq ft 60,854 113,568 115,000 per ton of metal produced. In the summer of 1944, the "reverse" leaching process was placed in operation and since it has been described,' no further description will be given. Other facilities and changes which have contributed to the process improvements were the scrubbing of fume from the melting and

Jan 1, 1953

By W. S. Reid

In March, 1938, E. P. Fleming, metallurgist for the American Smelting and Refining Co. inaugurated an investigation into the possibilities of recirculating the gases from Dwight-Lloyd sintering machines operating on lead charge, with the twofold object of concentration of the SO2 content and reduction in volume of total gas produced. The possibility of recovering a commercial grade of SO2 gas from D & L machines operating on lead charge had previously been considered by several investigators. Early History of Recirculation The Selby Smelter Commission Report, published by the Bureau of Mines in 1914, contains a chapter by A. E. Wells regarding results obtained at Selby, wherein some of the richer gas was recirculated through a hood over the pallets. Oldright and Miller of the U. S. Bureau of Mines had also made tests at Trail, B.C., and at Kellogg, Idaho. R. C. Rutherford, while at the Chihuahua, Mexico, Smelter of the American Smelting and Refining Co., in May, 1937, proposed recirculation of D & L gases to decrease the volume of gas handled by the baghouse. At none of these plants, however, was the operation commercialized. In July, 1938, Mr. Fleming, in correspondence with the Selby Plant, inquired regarding the possibility of obtaining 6 pct SO2 gas from the Selby D & L machines. At that time, the writer advised that there was slight possibility of obtaining 6 pct SO2 gas without re- circulation, but believed that it was possible with recirculation, and that experimental work toward that end should be tried at some plant where spare D & L machines were available. The foregoing statement was based on the following information then available— 1. Tests on Selby first-over machines showed 2.28 pct SO2 from first windbox and 1.03 pct SO2 from second windbox, and corresponding figures for second-over charge of 0.81 pct SO2 for first windbox and 0.08 pct SO2 for second windbox. 2. Oldright and Miller (US. Bureau of Mines) in 1932 at Bunker Hill, on 42 in. X 22 ft machines found: a. First-over charge—Maximum SO2 concentration (leaving cake) of 9.5 pct. b. First-over charge—SO2 concentration of over 8 pct from the 4 ft to the 12 ft points beyond the front dead-plate and that the concentration then dropped rapidly. c. That approximately 80 pct of the total sulphur eliminated on the second-over machines occurred during the travel of the pallets from the 1 ft to the 6 ft distances from the dead-plate. d. That approximately 94 pct of the total sulphur eliminated on the second-over machines occurred over the first windox. 3. Oldright and Miller (US. Bureau of Mines) in 1932, at Trail, on 42 in. X 50 ft machines found: a. First-over charge—SO2 varied from 2.0 pct to 5.5 pct (leaving cake) from the 12 ft to 28 ft points from the deadplate. b. That the average SO2 increased from 1.0 pct at 7 ft from dead-plate to maximum of 3.3 pct at 20 ft, then dropped to 1.5 pct at 40 ft. c. That on a 22 ft, second-over machine with an 11 in. bed the SO2 varied from 4.5 pct to 6.5 pct from the 2 ft to the 8 ft points from the dead-plate. d. That on the final roast, the SO2 concentration also varied across the pallets; that is, 2 1/2 pct at the side, increasing to 6.0 pct, 5 in. in, and to 7.0 pct at 10 in. to 20 in. in, then decreased vice versa at the opposite side. e. Concluded that most of the sulphur on a 22 ft machine was removed over the first 7 ft of the first windbox; therefore, they partitioned the first windbox so that the exit gas from the second 4 ft section was returned to the surface of the pallets over the fist 7 ft section, and during a seven-day trial the gas from the 4 ft section averaged 2.4 pct SO2, while the recirculated gas from the first 7 ft section only increased to 3.8 pct SO2. (Excess suction over the 7 ft section to prevent escape of SO2 laden gas from the 4 ft section caused dilution by air.)

Jan 1, 1950

By Irving Cadoff, Kurt Komarek, Edward Miller

Barium can be purified by equilibration with titanium. The melting point of barium was found to be 726.2° i 0.5 °C. The room-temperature lattice parameters of BaTe and Bask are 7.004 * 0.002A and 6.600 * 0.002A. Melting points for BaTe and Base were found to be 1510° * 30°C and 1830° ± 50°C, respectively. HIGH-purity barium and its compounds are difficult to prepare because of the reactivity of barium with the atmosphere and the large heats of formation of the compounds. Purification of barium by vacuum distillation,' and the preparation and properties of barium oxide2 and barium sulfide3 have been reported. However, little has been done on the homologous compounds barium selenide and telluride. PURIFICATION OF BARIUM Distilled barium obtained from King Laboratories was used as the starting material. The analysis supplied with the metal showed the presence of: 0.4 wt pct Sr, 0.001 pct Mg, 0.02 pct F, 0.003 pct Cu, 0.005 pct Na and less than 5 x 10-3 wt pct of any other metallic impurity. Analyses for oxygen and nitrogen were not available. Since there is evidence4 that any barium nitride present in the starting material may decompose on distillation producing nitrogen which can contaminate the distillate, further purification was performed. At elevated temperatures, any nitrogen and oxygen present in barium should be removed by reaction with titanium. Assuming that the solubility of oxygen in liquid barium is negligible near the melting point of barium, any oxygen present will be in the form of BaO. Removal of oxygen from molten barium is expressed by the equation: BaO(S)+ TixOy(S) = Ba(l)+ TixO(y+1)(s) where Ti,Oy and TixO(y+1) are solid solutions of oxygen in titanium. At 1000°C, the change in free energy for this reaction is negative for (y+1)/x +y+1) x (100) 17.5 at. pct O.5 Since reaction with commercially pure titanium (containing 0.07 wt pct oxygen) results in a free energy change for the reaction of -19 kcal per g-atom, slight solubility of oxygen in barium would not hinder the oxygen removal. Since comparable thermodynamic data are not available to permit calculation of the partition of nitrogen between liquid barium and titanium, a similar quantitative relationship cannot be obtained. However, on the basis of work by Kubaschewski and Dench,5 complete removal of nitrogen from liquid barium can be expected. Since the melting point of barium is depressed markedly by small additions of nitrogen,' the change in melting point during reaction of barium with titanium was used to follow the purification reaction. MELTING POINT OF BARIUM A 50-g sample of barium was sealed by arc welding under argon into an all titanium crucible provided with a thermocouple well. The melting point of the sample was determined by thermal analysis, using a Pt/Pt-10 pct Rh thermocouple which was calibrated according to National Bureau of Standards specification6. The crucible was then heated for 48 hr at 950°C in vacuum and the melting point redetermined. This procedure was repeated until three successive thermal analyses agreed within ±0.5oC, the limits of error of the analysis. The melting point increased from an initial value of 720.0°C to a final value of 726.2°C. Analysis on samples quenched from 950°C gave a solubility value of 0.004 wt. pct Ti. Assuming that the titanium-barium phase diagram is similar to those of titanium-magnesium7 and titanium-calcium,8 the solubility of titanium in liquid barium decreases with decreasing temperature. Therefore, the solubility of titanium in liquid barium should be less than 0.004 wt. pctat the melting point (726oC), and the effect of dissolved titanium on the melting point would be negligible. Addition of up to 3 wt pct Sr does not significantly change the melting point of barium,7 so that the effect of the 0.4 wt pct Sr in the starting material will also be negligible. The value of 726.2" ± 0.5C obtained for the melting point of barium can be compared .with a determination carried out by Keller and coworkers in low-carbon steel crucibles,' who obtained a value of 725± 1C, using barium purified by fractional distillation. The higher value obtained in the present investigation is indicative of the effectiveness of titanium in removing traces of nitrogen. PREPARATION OF BaTe AND Base The compounds were prepared by direct reaction

Jan 1, 1961

By F. Wald, A. J. Rosenberg

The general features of the constitution of the B-Pt system were determined using standard rnetal-lograph~c, thermoanalytic, and X-ray diffraction techniques. Three compound were found. Two of these, Pt3B and Pt,B, are formed by peritectic reactions at 523° and 890°C, respectively. The third, Pt3B,, is congruently melting with a flat maximum at 940°C but decomposes eutectoidally in to Pt,B ant1 boron nt - 600° to 650°C. THE low-temperature allomorph of boron (red, simple rhombohedra1 a boron) is of scientific and technological interest as an elemental semiconductor.' However, the studies of this material have been hampered by its reported instability above 1200"~ which precludes crystal growth from the melt (mp - 2200°C). Crystallization from platinum solutions has been suggested as an alternative crystal-growth technique, but has met with only limited success.' The technique depends upon the existence of a significant difference between the eutectic temperature and the transformation temperature of boron. In order to clarify the conditions for further crystal-growth experiments, we found it desirable to redetermine the main features of the B-Pt phase diagram since previous reports on the system1'5'6'7 are in marked disagreement. EXPERIMENTAL The experimental methods used were thermal analysis, metallography, X-ray analysis, and, to a lesser extent, measurements of microhardness. Most of the alloys were prepared from spectrograph-ically standardized boron obtained from Johnson-Matthey &Co., Ltd. (212 ppm impurities, exclusive of carbon and oxygen) and platinum powder obtained from F. Bishop & Co. (200 ppm impurities, mainly of other platinum group metals). Some alloys were also prepared with very high-purity, float-zone refined boron (99.9999 pct obtained from "Wacker Chemie" and extrahigh-purity platinum (99.999 pct) obtained from Johnson-Matthey & Co., Ltd. The reported results did not depend on the choices of these starting materials. Five-gram alloy specimens containing 10, 20, 25, 27.5, 30, 33.3, 34, 35, 37, 37.5, 38, 39, 40, 41, 42, 43, 45, 50, 55, 60, 70, and 80 at. pct B were made by melting the elements together in boron nitride crucibles using rf heating of a graphite susceptor, either in vacuum or under high-purity argon. All alloys were heated to at least 1800°C for -5 to 15 min. Most of the alloys did not wet the crucibles when the latter were outgassed by preheating under vacuum. In any event, no weight loss was detected after melting, and the nominal composition was assumed for all specimens. Thermal analysis on 2.5-g samples were carried out in boron-nitride crucibles under a vacuum of 5 x X torr. The apparatus was heated in a "Kan-thal A 1" wound furnace, which limited the maximum temperature to about 1100°C. The output of the indicator thermocouple was fed to a dc recorder with a 1-mv full-scale span and an adjustable zero. The apparatus was calibrated repeatedly, using the freezing points of high-purity aluminum, silver, and gold. The results justified the use of the NBS voltage vs temperature tables for Pt/Pt 10 pct Rh thermocouples. All thermal analyses were run at least twice and both the heating and cooling effects were recorded. Most of the alloys had a very strong tendency to supercool. However, the use of mechanical vibration permitted reproducibility within *5°C for all alloys, except in the region around 40 at. pct B. Only the cooling effects are plotted in Fig. 2, since they appear to be more reliable. For metallography, the alloys were cut with a diamond cutting wheel, cast in a polymethacrylate resin, ground and polished with diamond paste, and etched with dilute aqua regia, a common etch for platinum alloys. Both copper and molybdenum radiation were employed to obtain X-ray diffraction data using Debye-Scherrer cameras and a "Norelco" diffractometer Diffractometry with high scanning speeds (1 deg per min) using nickel filtered CuK, radiation was used to identify the main regions of the diagram. However, molybdenum radiation was used for the detection of boron, since the latter showed very strong absorption and fluorescence effects with CuK, radiation. RESULTS AND DISCUSSION Three intermediate compounds, corresponding to the compositions Pt3B, Pt2B, and Pt3B2, were found in the system. Fig. 1 reproduces their X-ray diffraction spectra, together with those of pure boron and pure platinum. As can be seen from the thermal-analysis data in Fig. 2, Pt3B and Pt2B are formed by

Jan 1, 1965

By James V. Thompson

ENGINEERS from industrialized countries are frequently called upon to examine mining operations in primitive areas and make recommendations regarding mechanization and modernization. They often set forth with self-confidence, knowing full well that all that is needed is their experience and several shiploads of mining machinery, and at times they mentally provide the answers before the problems have been clearly stated. In primitive areas it is absolutely essential that the examining engineer spend enough time at the site to acquire a thorough understanding of what is being done now and why it is done the way it is. The objective here is to state in simple terms some of the problems that may be encountered, in- as much as solutions, if they can be found at all, will differ with each experience.

Jan 8, 1958

By W. W. Wen, S. C. Sun

The objective of this investigation was to study the electrokinetic behavior of oxidized coals to indicate the feasibility of separating oxidized coals from ash materials and pyrite by an amine flotation process. The effects of soluble inorganic electrolyte products from coal oxidation were also examined. The electro-kinetic behavior of coals of different rank and degree of oxidation were studied by an electro-phoreses technique. Generally, increasing the oxidation increases the negative value of the zeta-potential and decreases the isoelectric point (IEP). Flotation results indicate that the flotation recovery increases with decreasing pH values, and that with ferrous sulfate at pH 6.5 the flotation recovery is optimum while the pyrite is depressed. Comparing the flotation results with the electokinetic results verified that in the presence of ferrous sulfate, the maximum hydro-phobicity of oxidized coal with dodecylamine and frother is near its IEP, which is around pH 6.5 to 7.0.

Jan 1, 1978

By William E. Ford, Edward Salisbury Dana

1. Normal Class (1) Galena Type 2. Pyritohedral Class (2) Pyrite Type 3. Tetrahedral Class (3) Tetrahedrite Type 4. Plagiohedral Class (4) Cuprite Type 5. Tetartohedral Class (5) Ullmannite Type Mathematical Relations of the Isometric System 50. THE ISOMETRIC SYSTEM embraces all the forms which are referred to three axes of equal lengths and at right angles to each other. Since these axes are mutually interchangeable it is customary to designate them all by the letter a. When properly orientated (i.e. placed in the commonly accepted position for study) one of these axes has a vertical position and of the two which lie in the horizontal plane, one is perpendicular and the other parallel to the observer. The order in which the axes are referred to in giving the relations of any face to them is indicated in Fig. 85 by lettering them a,, a2 and a3. The positive and negative ends of each axis are also shown.

Jan 1, 1922

By Hugh Marriott

MANGANESE and its ores have been recently dealt with in comprehensive papers to the Iron and Steel Institute by Sir Robert Hadfield, and in a series of papers read before the A. I. M. E. at the Cleveland meeting. I have taken the opportunity of adding this mineral, to my records of the "World's Mineral Production and Consumption," as recently pub-lished in the Economist ?. The tables bring out the following significant facts: The world's production has increased by 10 per cent since 1913. India's production has increased by 3 per cent since 1.913, the supply from this source now being 31.1 per cent of the world's output. Russia is now producing at about half its pre-war rate and yields 19 per cent of the world's production. West Africa supplies 12.5 per cent of the world's total output. Brazil's present output is 2.5 times that of the pre-war period, being 11.3 per cent of the world's output.

Jan 9, 1927

US 4,152,143-Continuous precipitation of cement copper from an aqueous ore leach solution mixed with pieces of iron as the precipitant Copper depositing on the pieces of iron is loosened and removed therefrom by means of constant but regulated oscillating movement of the pieces of iron in a horizontal elongated chamber, and the loosened copper is separated and collected from the mixture E Kausel and R Nissen, assigned to Klockner-Humboldt-Deutz A G May 1, 1979 8 pp (75-100) Filed 1-12-78 (868,981) (Drawings below) [ ] US 4,156,711-Removal of metal impurities from an acidic zinc or cadmium solution prior to electrolysis. Impurities such as manganese, cobalt, nickel, and thallium are selectively precipitated by contacting the solution with persulfuric acid or an ammonium or alkali metal salt thereof while maintaining a pH value of from 1 5 to 4 5 This patent is a continuation-in-

Jan 1, 1980

By J. R. Ross, J. B. Rosenbaum

Bureau of Mines research has resulted in the development of fluid- bed ion-exchange columns for recovering uranium from slime pulps. In pilot plant tests, slime slurries containing up to 6 percent solids were processed at flow rates of 10 gallons per square foot per minute with high uranium recoveries and efficient resin loadings. Uranium was effectively eluted in a laboratory fluid-bed elution column at eluate-to-resin ratios of less than 5:1 and eluate flow rates of 3 gallons per square foot per minute. Construction costs of mills using these improved ion exchange techniques are estimated to be 25 percent less than for mills using solvent extraction of clear solutions. For mills having a capacity of 2,000 to 2,500 tons of ore per day, the saving would be in the range of $2.5 million. In addition, a saving of about $0.80 per ton of ore in total operating costs is indicated.

Jan 1, 1973

Single orders 2.5 c. Pamphlets 10. c. each in lots of three or more. Pamphlets 5 c. each in lots of fifty or more. These prices prevail for orders for pamphlet, of the same or different titles. The pamphlets listed on the following sheets are advance copies printed to facilitate discussion at the meetings of the Institute. They are offered for sale at the reduced prices given above as long as the supply, lasts. This list is published in the Bulletin in order that members may have the first opportunity to secure pamphlets, which sometimes are in such great demand that the supply is exhausted before the wants of members can be supplied. The following list includes only a fraction of the pamphlets that have been published by the Institute. Any other paper published by the Institute may be obtained for the price of $1, except those published in Volume XXXI, which are rare.

Jan 5, 1917

By J. S. Browning

The pegmatites of the Kings Mountain-Lincolnton, N. C., area constitute the largest known domestic reserve of beryl and spodumene. The reserve is estimated to contain 90 million tons of pegmatic material with 1,280,000 tons of recoverable Li2O (lithia) as spodumene.1 The pegmatites also contain 0.4 to 0.5 pct beryl disseminated throughout the orebodies. The pegmatites may contain a potential reserve of 240,000 tons beryl, equivalent to approximately 34,000 tons of BeO. Different flotation methods for separating beryl from feldspar or quartz, or both, have been developed by various investigators.2,3,4,5,6,7 On the other hand, published information is limited on concentration of spodumene-beryl ores. As the response of beryl and spodumene to flotation is essentially the same, a successful separation of the two minerals depends upon use of a selective depressant or a selective collector for one of the minerals.

Jan 7, 1961

"The mountains of Utah contain one of the largest deposits of high grade bituminous coal in the world. According to the United States Geological Survey, there are 13,130 square miles of land known to contain workable coal, and these extensive fields contain 196,000,000,000 tons of coal. More remarkable than the extent of the coal fields is the thickness of the coal beds. Over three-fourths of the output of coal in Utah is recovered from beds ranging from 8 to 17 feet in thickness, as compared to one-eighth of the output of the entire country from such beds. In 1917, Utah mined one-third of its coal from seams at least 16 feet thick, compared to one-half of one per cent of the total bituminous output of the country from like seams.Coal at Wales, in Sanpete County, and in the vicinity of Coalville, Utah, was, it is reported, the first discovered by white men in the state. Wales claims the distinction of having produced the first coal mined in Utah. Two men, who had been coal miners in Wales, learned of the coal from an old Indian chief who called it ""rock that would burn."" In 1857, the town of Wales was founded and coal mined, and in 1858 some coke was manufactured and hauled by ox team to Salt Lake City. South of Wales is Castle Valley, in Wasatch Plateau field. From 50 to 60 miles of the Old Spanish Trail from Santa Fe, New Mexico, to Monterey, California, lies in Castle Valley. The coal in this field may or may not have been known at the time the trail was used extensively. The first published reference to this coal, however, was made by a party of the Corps of Topographic Engineers in their journal for October 11, 1853.After the completion of the Union Pacific railroad in 1869, mining on a commercial scale was attempted. In 1876 the Utah and Pleasant Valley railroad commenced operations between Scofield, in Carbon county, and Springville, Utah county, and following the year 1878, when the Rio Grande Western railway began construction through the Carbon county field, development increased until in 1900, when large smelters commenced operations in Salt Lake valley and gave coal mining in Utah an impetus that first carried it to an annual output of a million tons. During the past fifteen years many new mines have been opened, and with the construction of the Utah railway, an exclusive coal road, from the properties of the United States Fuel company in Carbon and Emery counties to connect with the Union Pacific system at Provo, the state reached a maximum production of 6,005, l 99 tons in 1920."

Jan 1, 1925

We did install one 100% brick bottom in our #33 furnace which is basically the same design as Inland's furnace. We had previously embarked on a program of replacing all bottoms in our 300 ton furnaces every 2nd campaign which would be about every 2000 - 2300 heats. This had been necessitated by the effect of our rather high oxygen blowing rates and our desire to maintain a minimum bottom interval level. This meant that we were able to compare bottom performance of various types of materials on a realistic bas is. Since furnace availability is critical to our operation, we are organized to employ every piece of equipment and all the necessary man power to complete a rebuild in the shortest possible time. A 300 ton furnace requires 7.5 days to rebuild. If a new bottom is to be installed an additional 2.5 days is added - 24 hours for tear out and 36 hours for bricklaying - making a total of 10 days.

Jan 1, 1972