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By J. E. Elliott, K. O. Miller

Solubility studies were carried out to establish the phase distributions for various Fe-Ni-Pb-C alloys at temperatures where the metallic components exist as liquid solutions. Temperature us composition diagrams for the Ni-Pb, Fe-Pb, Fe-Ni-Pb, and Ni-Pb-C systems are derived by employing various approximations in conjunction with the data. Results are summarized for 1550°C in a quaternary phase diagram of the Fe-Ni-Pb-C system. BECAUSE surprisingly little information has been published on the phase diagrams of the Ni-Pb, Fe-Pb, Fe-Pb-Ni, and Fe-Ni-Pb-C systems, a study of these systems was undertaken to ascertain the important phase relationships in the temperature range of 1300" to 1550°C. Measurements were also made on the carbon-saturated systems in the hope that they would assist in the interpretation of the systems without carbon. This paper reports the results obtained from the simple equilibration of the various liquid and solid phases. EXPERIMENTAL PROCEDURE The experimental technique involved holding appropriati quantities of the metals in an alumina crucible, or in a graphite crucible when saturation of the melt with carbon was desired, for sufficient time at the desired temperature to ensure equilibrium. Then a sample of each liquid phase presen was drawn into a small-bore silica tube. This sample was withdrawn quickly from the furnace, cooled, and sent to the chemical laboratory for analysis. The cell assembly used is shown in Fig. 1. Durin the work on the Fe-Pb-Ni system, it was placed in a furnace wound with 20 pct Rh-80 pct Pt wire. This furnace eventually failed and subsequent studies were carried out between 1350" and 1475°C in a tube furnace heated by silicon-carbide resistance elements. A protective atmosphere of argon with approximately 10 pct hydrogen was supplied to the cell assembly at a gage pressure of 1 in. of water. Hydrogen was passed over palladized alumina and then anhydrous calcium chloride for purification. Argon was purified of oxygen and water vapor by passing it over copper gauze at 550°C and then through a calcium chloride drying column. The gases were mixed and redried before they entered the equilibration cell. Temperature was measured by calibrated Pt/Pt-10 pct Rh thermocouples and a Rubicon Type B potentiometer. The thermocouples were standardized against the melting points of pure nickel

Jan 1, 1961

By J. R. Dunn

Planning quarry operations and control of the quality of rock materials at Hudson Cement Co. at East Kingston, N. Y., are special problems because of multiple uses for the stone and the great structural complexity of the rocks. Problems have been largely solved by detailed geologic work. These geologic studies have paid dividends in long and short range planning, in assessment of reserves, in vastly reduced cost of chemical analyses, and in reduced drilling costs. Limestones of the Hudson Valley outcrop along the Hudson River from Albany to Kingston. Old established cement companies are located just south of Catskill and just east and southeast of Hudson, N. Y. The new Atlantic Cement plant is being constructed at Ravena. Hudson Cement located at East Kingston, is a newcomer and is closest to the New York metropolitan area (Plate I).

Jan 11, 1961

By PDF

C. 0. FAIRCHILD, Washington, D. C. (written discussion*).-Referring to the paragraph entitled "Effect of change in temperature of absorbing glass on its transmission," Dr. Foote and the writer have been using, since

Jan 11, 1919

By J. O. Brittain, E. P. Lautenschlager, F. Felberbauer

This investigation was undertaken to evaluate the effect of a dispersed phase in a iron upon the strain hardening and the stress dependency of dislocation velocity as inferred from the strain-rate sensitivitv. Experiments were made in a-iron specimens with controlled amounts of carbon and/or A12O3. They were tested at various temperatures between 195' and 373 'K under a variety of conditions oj-concentration, strain rate, and quench aging. The resulting yield strength, flow strength, and strain hardening increased with addition of Al2O3. The parameter m, measured from changes in strain rate, was xsed to describe the stress dependency of the dislocation velocity. m was found to increase with additions of A12O3, increasing carbon in solution, and with increasing temperature. When applied to a recent model for yielding based upon dislocation multiplication and velocity characteristics, the values of m alone did not successfully predict yielding for the materials of this investigalion, but had to be adjusted with a consideration of the number of unlocked dislocations nucleated heterogeneously at discontinuities or inclusions. The change of yield strength with Al2O3 Interpar-ticle spacing appeared to obey a theory of Orowan. EVER since the concept of dislocations has been introduced to explain plastic deformation in crystalline materials, the origin of dislocations and the source of the number of dislocations required to account for plastic deformation have been persistent questions. Ruling out the possibility of homogeneous nucleation,' Gilman2 drew attention to the various cases of heterogeneous nucleation as the source of dislocations, whereas Frank and Read3 introduced the Frank-Read source. However, Gil-man found that the Frank-Read sources did not play a dominant role in the deformation of LiF crystals, but that small precipitates are often, if not always, associated with the nucleation of dislocations. In LiF crystals, however, most of the dislocations arose through the multiplication of moving dislocations in a mechanism described by Koehler4 and Orowan,5 Thus, relatively few precipitates could account for a large number of dislocations. A similar observation of dislocation nucleation at inclusions of precipitates was made by Stein and LOW' on Si-Fe crystals. Their crystals contained

Jan 1, 1964

By L. E. PORTNER

INCREASING military demands on the petroleum industry have brought into bold relief the crude-oil reserves now available to meet combined military and civilian demands, emphasizing the necessity for a greater efficiency in recovery from what has been discovered than ever before, particularly in light of the absence of new discoveries. This situation-and the fact that the industry, as well as members of the Government charged with governing oil production, desire to meet all crude-oil demands made of the industry with the least loss in tangible reserves through production practices-paves the way for increasing application of sound principles of production engineering and conservation.

Jan 1, 1944

By Alexander Knoll, Dwight L. Baker

THIS paper is a report on work undertaken to investigate the results and conclusions of Ravitz and Porter1,2. that galena freed of surface oxidation products and lead carbonate ("clean" galena) is water-repellent, and that the action of xanthates in flotation is the action of a cleansing agent, enabling oxidized galena particles to expose a pure lead sulphide, water-repellent surface. The apparatus, in construction and use, was essentially that of Ravitz and Porter. The only significant modification introduced by the present authors was the substitution of a three-necked flask for the flotation cell as the "reaction vessel." Our procedure was to place 50 grams of freshly ground, minus 200-mesh galena in the reaction vessel, sweep out all molecular oxygen from the system with oxygen-free nitrogen, and proceed to wash the galena surface free of its oxidation products with repeated small portions of (I) ammonium acetate (500 c.c. of water, 200 grams of ammonium acetate) or (2) ammonium chloride, hydrochloric acid (2 liters containing 200 grams of ammonium chloride and 25 c.c. of 1.18 sp. gr. hydro chloric acid). The galena was next washed with many 100-c.c. portions of oxygen-free, distilled water. The galena was finally considered free of soluble salts when wash water that had been in contact with the mineral for at least 48 hr.* gave negative tests for: (I) lead ion with sulphide; (2) chloride with silver ion; (3) acetate with cuprous chloride, sodium chloride; and (4) ammonium ion with Nessler's reagent. Next 500 c.c. of potassium ethyl xanthate solution, free of dissolved oxygen, was run onto the "clean" galena particles. For this system there were determined: I. The wetting properties of the clean galena particles by shaking the reaction flask and noting the degree of mineral collection at the liquid-air interface. This was, of course, simply a qualitative test, but it proved adequate for our purpose. 2. The removal of xanthate ion from the potassium xanthate solution on being shaken with the "cleansed" mineral. Xanthate concentrations were determined by iodine titration according to the methods of Taylor and Knoll.3 3. The pH of the xanthate solution after having been shaken with the "cleansed" galena. The pH was determined colorimetrically.4 The results of five experiments of the type mentioned above are given in Table I.

Jan 1, 1941

By H. H. Otto

COMPARED with 1939, the year 1940 has seen no material change in the production of anthracite. Many factors seem to indicate a stabilized anthracite production of approximately 50 million tons per year. The present war has stimulated demand in the Cana¬dian and New England markets, which were formerly furnished with a portion of their needs from Great Britain and other European countries. Neither has there been any material change in the "bootleg coal" situation. This problem is more serious in the Southern anthracite field than in the Hazleton, Wilkes-Barre, and Scranton areas. One reason for this is the nearness of the Southern field to the large anthracite markets in Philadelphia, Washington, Baltimore, and Harrisburg. During the past year no new large

Jan 1, 1941

By L. Zwell, H. A. Wriedt

In describing their procedure for measuring the lattice parameters of solid solutions, Abrahamson and Lopata report (p. 77) the final heat treatment of their alloy specimens as "700°C for 100 hr, followed by a furnace cool". The isothermal part of this treatment may be expected to precipitate solute in excess of the stable a solid-solution limit at 700°C; the subsequent slow cooling is likely to reduce the dissolved solute still further. Fig. 1 (upper) presents the data for titanium alloys so he;rt-treated and shows the lattice parameters of solid solutions containing up to 3.5 at. pct Ti; Fig. 17 (lower) shows 2 at. pct Ti as the solubility limit in a iron at 700°C. Figs. 1 and 17 are thus incompatible. The paper contains comparable incon~patibilities for zirconium alloys, for niobium alloys, and for tantalum alloys. The final heat treatment at 700°C may also be responsible for the anomalous "knee" in the lattice-parameter data for nickel alloys, Fig. 3. The "knee" composition is located near the 700°C limit of the stable a solid-solution field;37 alloys of the experimental composition range with more nickel than the "knee" composition are two-phase at 700 C and prolonged heat treatment of them at 700°C would tend to produce inhomogeneity rather than homogeneity. In Figs. 4 and 7, the composition ranges of the zirconium, hafnium, and niobium alloys examined terminate at alloy concentrations of 0.1 to 0.2 at. pct. These metals form very stable oxides and their partial removal from solid solution in iron by impurity oxygen may be expected. We believe that the authors should have reported the procedure by which they distinguished the amounts of alloying elements in solution and in oxide. The diagrams pertaining to copper in Figs. 3 and 18 (lower) are almost certainly incorrect. Three recent investigations of this system38-40 all substantially agree on the solubility of copper in a iron, finding it to be much larger than that reported by Abrahamson and Lopata. The change of the lattice parameter with composition reported by Abrahamson and Lopata is too large by a factor of three to five, as seen by comparison with the findings of other investigators.41738 Moreover, the authors violate, in Fig. 18, the accepted Fe-Cu constitution diagram37 by ignoring the eutectoid at about 850°C.

Jan 1, 1967

By V. V. Clark

WHEN a district is more or less primitive, and a trained mining engineer attempts single- handed to prospect it according to old standards, he generally fails. He has not the ability to live out in the open alone for months at a time and carry on with enthusiasm and determination like the old-time prospector. But the same engineer, placed in an organized group where modern prospecting methods are employed, is immediately put on his mettle and his chances of winning are greatly increased. Marsman Investments, Ltd., with headquarters in Manila, has at the present time, Sept. 4, 1937, six prospecting parties in the Netherland East Indies. Three of these groups are combing their assignments for lode mines, studying structures, developing and reaching out into veins and zones with diamond drills. The other three are searching for placer mines with pans, pits, and Empire drills. I am in charge of one group seeking commercial gold placers on the Island of

Jan 1, 1937

By R. W., Ludt

THE use of froth flotation for the separation of minerals has become one of the most important of ore dressing processes. Its particular adaptability to the enrichment of low grade ores has made the process an important factor in the national economy. The methods have been extended to the recovery of a great number of minerals. Among the few minerals which have resisted efforts toward industrial flotation is chrysocolla, a hydrated partly colloidal copper silicate. Chrysocolla, being a product of natural oxidation, has been found to occur in small quantities with many ores which are recovered by flotation methods. In present practice, these small quantities of copper silicate pass off with the tailings and are lost. The advantages to be gained by a satisfactory process for the recovery of chrysocolla is apparent. Any application of principles which points a way toward the satisfactory industrial flotation process for copper silicate would be of advantage. This paper presents an attack on this problem.

Jan 1, 1949

By C. K. Leith

THE interdependence of nations in regard to mineral supplies has grown apace with the expanded needs of industry, with depletion of reserves, and with advances in technology. This increased mutual dependence raises many questions of foreign economic policy of special importance in our postwar planning. Realization of the urgent need for the development of a general mineral policy broadly based on national requirements led to discussions of the problem between officials of the Department of State and myself, as a result of which it was suggested that I make an informal and unofficial canvass of the views of mineral specialists of the country on foreign mineral policy.

Jan 1, 1946

By E. C. Houston

The phosphate ores mined in middle Tennessee typically consist of granular rock phosphate particles disseminated in a clayey matrix. In the TVA plant near Columbia, Tenn., the phosphate ore is mined, made into a slurry with the addition of a small amount of sodium hydroxide as dispersant, and treated in a hydroseparator to remove minus 10 micron material. The hydro-separator underflow, comprising a rough concentrate, is transported by pipeline to the plant; the hydro-separator overflow, comprising a tailing, is flocculated by addition of calcium sulphate and is discharged to settling ponds at a rate of about 1400 gpm. Sedimentation in the ponds produces a clarified effluent, which may be recycled for use as process water or discharged to surface drainage. This method of tailing treatment is not entirely satisfactory since poor sedimentation characteristics of the tailing result in poor ultimate utilization of pond storage volume.

Jan 1, 1949

By A. Lee Barrett

AN accelerated trend toward mechanical mining was noted in 1940, calling for improvements in and better performance of transportation, hoisting, and ventilating equipment. One of the most interesting experi¬ments in transportation is the track shuttle-car operation first put into use by the Princeton Mining Co. in Indiana and later at the Montour 4 mine of the Pittsburgh Coal Co. This system is based on the use of 10-ton drop-bottom mine cars operating on track and han¬dled by an ordinary gathering loco¬motive. These mine cars are loaded and taken in trips of two to a central dumping station which serves four or less loading machines. The dumping station consists of two standard chain-and-flight room conveyors, approximately 50 ft. long placed side by side approximately 4 ft. below the track from which the drop-bottom cars are dumped. These conveyors are operated at low speed and discharge into two similar elevating conveyors which operate at a higher speed and convey the coal to a trip of standard mine cars. A dumping station is usually located so that approximately 500,000 tons of coal may be handled through it before a move is required. This plan appears to have considerable possibilities for the mine equipped with small mine cars and standard locomotives since the advantages of large mine cars can be secured at a fraction of the cost required to install such cars throughout the mine. It appears logical that the future will see a much wider use of this modification in transportation.

Jan 1, 1941

By Christopher J. Bise

Introduction In August 1977, the federal Surface Mining Control and Reclamation Act was signed into law. It stated that: "The Congress finds and declares that because of the diversity in terrain . . . and other physical conditions in areas subject to mining operations, the primary governmental responsibility for developing. authorizing, issuing, and enforcing regulations for surface mining and reclamation operations subject to the Act should rest with the States." Section 516 of Title V (Control of the Environmental Impacts of Surface Coal Mining) of the Act deals with the surface effects of underground coal mining operations. "Each permit issued under any approved State or Federal program pursuant to this Act and relating to underground coal mining shall require the operator to adopt measures consistent with known technology in order to prevent subsidence. causing material damage, to the extent technologically and economically feasible, maximize mine stability, and maintain the value and reasonable foreseeable use of such surface lands, except in those instances where the mining technology used requires planned subsidence in a predictable and controlled manner: Provided, that nothing in this subsection shall be construed to prohibit the standard method of room and pillar mining." This section raises many questions. Precisely what is the "reasonably foreseeable" future as far as land use is concerned? And what is the "standard method of room and pillar mining"? The first part of the paragraph seems to rule out longwall mining, but isn't longwalling a "predictable" manner of "planned subsidence"? Does the Act take into account variations among mining methods in differing regions or coal seams? With these questions and the need to comply with the Act's provisions in mind, many states may turn to the Pennsylvania Bituminous Mine Subsidence Act of 1966- the only comprehensive subsidence act passed by any state-as a model for their own programs. Thus, it is very important to evaluate Pennsylvania's Act to see whether its basic assumptions can accommodate national application. This paper will note the Subsidence Act's provisions and guidelines, briefly analyze the current state-of-the-art in subsidence damage prevention and control, and list several recommendations for altering the Act's application guidelines for different mining areas.

Jan 1, 1982

By AIME AIME

THE 129th meeting of the American Institute of Mining and Metallurgical Engineers convened at New York City, in the Engineering Societies Building, Feb. 18-20, 1924. On February 21 an excursion was made to the Bethlehem Steel Co., at Bethlehem, where about 200 members and guests were splendidly entertained. An illustrated description of the Bethlehem Plant will be published next month. The meeting and excursion were largely attended; the registration at New York totalled 1276 versus 1201 in 1923. William Kelly, long identified with the iron-mining industry of the Lake Superior district, was elected President of the A. I. M. E. for the coming year, at ,the annual business meeting, Feb. 19, succeeding E. P. Mathewson. The following Directors were also elected (the date signifies year of termination of office; the final figure indicates the "District" the Director represents).

Jan 1, 1924

By Blair R. Benner

This paper describes the installation and operation of a Texas Nuclear on-line silica analyzer (NOLA) coupled with a Leeds and Northrup Microtrac particle-size monitor (Microtrac) at U.S. Steel's Minntac taconite concentrator. An automatic sampling system provides the NOLA with samples of final concentrate. After the sample is analyzed for silica by the NOLA, it is pumped to the Microtrac for size and surface area measurement. A sample is analyzed every six minutes, providing the control room with the silica concentration, the percent passing 270, 400, and 500 mesh, and an equivalent Blaine surface area number. When fed a slurry of final concentrate containing between 20 and 70% solids and 5 to 6% silica, the NOLA analysis is within ±0.2% of the wet chemistry silica. The agreement between the Microtrac output and standard screen analyses is ±1.2% at 270 mesh; ±1.5% at 400 mesh, and ±2% at 500 mesh. The poorer disagreement at the finer sizes is mainly due to inaccuracies in screening at 400 and 500 mesh. The agreement between Microtrac surface area a d laboratory Blaine surface area is about 9 ±80 cm 2/g. These instruments provide rapid and reliable feedback information to the concentrator and feed forward information to the agglomerator.

Jan 1, 1984

By A. L. Titchener, M. B. Bever

FROM their investigation of the martensitic transformation in Cu-Zn alloys, Greninger and Mooradian' concluded that there was no critical temperature at which martensite formation began in this system. Recent unpublished work by Gen-evray With two compositions of brass revealed the existence of a critical temperature, which is a function of composition and stress. In the work reported here the temperature range of the martensitic reaction was studied as a function of composition in high purity Cu-Zn alloys. The specimens were about 4 in. long with a diameter of 1/16 in.; their compositions are given in Table I. They were heated under vacuum for 5 min at 5" to 10°C below the temperature of incipient melting, and quenched into brine at about — 10°C. Specimens of alloys C, D, E and F were obtained with little or no precipitated a phase. Many attempts yielded only three usable specimens of alloy B, and even these contained appreciable amounts of a. All efforts failed to preserve metastable p in alloy A (containing 38.02 pct Zn and 0.002 pct each of Pb and Fe). The transformation was studied by measuring the electrical resistance during continuous cooling and heating of each specimen at similar rates. The cooling media were alcohol with dry ice from room temperature to — 78°C and a bath of petroleum ether and methyl cyclohexane (75:25), cooled by liquid nitrogen, from —78" to about —150°C. Readings were also taken at —195 °C in liquid nitrogen. Fig. 1 illustrates a typical experiment. The relative resistance is obtained by assuming the known

Jan 1, 1955

By Alexander Knoll, Dwight L. Baker

THIS paper is a report on work undertaken to investigate the results and conclusions of Ravitz and Porter1,2 that galena freed of surface oxidation products and lead carbonate ("clean" galena) is waterrepellent, and that the action of xanthates in flotation is the action of a cleansing agent, enabling oxidized galena particles to expose a pure lead sulphide, water-repellent surface. The apparatus, in construction and use, was essentially that of Ravitz and Porter. The only significant modification introduced by the present authors was the substitution of a three-necked flask for the flotation cell as the "reaction vessel." Our procedure was to place 50 grams of freshly ground, minus 200-mesh galena in the reaction vessel, sweep out all molecular oxygen from the system with oxygen-free nitrogen, and proceed to wash the galena surface free of its oxidation products with repeated small portions of (I) ammonium acetate (500 c.c. of water, 200 grams of ammonium acetate) or (2) ammonium chloride, hydrochloric acid (2 liters containing 200 grams of ammonium chloride and 25 c.c. Of 1.18 sp. gr hydrochloric acid). The galena was next washed with many 100-c.c. portions of oxygen-free, distilled water. The galena was finally considered free of soluble salts when wash water that had been in contact with the mineral for at least 48 hr.* gave negative tests for: (x) lead ion with sulphide; (2) chloride with silver ion; (3) acetate with cuprous chloride, sodium chloride; and (4) ammonium ion with Nessler's reagent. Next 500 c.c. of potassium ethyl xanthate solution, free of dissolved oxygen, was run onto the "clean" galena particles. For this system there were determined: I. The wetting properties of the clean galena particles by shaking the reaction flask and noting the degree of mineral collection at the liquid-air interface. This was, of course, simply a qualitative test, but it proved adequate for our purpose. 2. The removal of xanthate ion from the potassium xanthate solution on being shaken with the "cleansed" mineral. Xanthate concentrations were determined by iodine titration according to the methods of Taylor and Knoll.3 3. The pH of the xanthate solution after having been shaken with the "cleansed" galena. The pH was determined colorimetrically.4 The results of five experiments of the type mentioned above are given in Table x.

Jan 1, 1941

By AIME AIME

AN unusual interest in the question of orienting the young college man in the mineral industry was shown in a well-attended session* of the Engineering Education Committee on Monday afternoon. About seventy-five employers and educators of mining engineers were present and took part in the discussions.

Jan 1, 1929

By R. V. Horrigan

High purity ZrC14 (25 to 200 ppm of metallic impurities) can be readily prepared in simple apparatus by thermal decomposition of alkali chlorozirconate fused salts at 500° to 600°C and at atmospheric pressure. Suggested phase diagrams for the systems NaCI-ZrC14 and KCI-ZrCI, are presented. ALKALI chlorozirconate compositions — anhydrous fused mixtures of ZrCl4, NaC1, and KC1— are manufactured commercially and are used by the magnesium industry to introduce zirconium into magnesium alloys. Zirconium refines the grain size and improves the physical properties of many important magnesium alloys. In the course of working with chlorozirconate compositions of high ZrCl4 content, it was noticed that these salts decomposed progressively itwaswith increasing temperature to yield considerable amounts of a ZrCl4 sublimate of high purity together with a solid chlorozirconate residue. Further research led to: 1—improvements in the

Jan 1, 1956