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By Mark E. Smith

To allow recovery of gold values from ore which cannot be economically processed by the mill, Pinson Mining Company has developed a run-of-mine heap leaching facility. In order to estimate production scale recovery rates, reagent consumption and percolation problems, a series of pilot scale tests were performed. These tests typically consisted of 3,630 metric tons (mt) (4,000 tons) leach ore at a grade of .94 to 1.56 grams Au per metric ton (g/mt) (.03 to .05 oz. Au/ton). Test heaps were loader stacked to approximately 4.3 meters (14 feet) high. Information from these pilot scale tests was employed in the design and construction of the production scale facility. Parameters such as spray rate, leach cycle, sprinkler placement, and barren solution chemistry were determined by the pilot tests.

Jan 1, 1984

By J. Gordon Parr, L. P. Srivastava

DUWEZ1 has shown that pure titanium and pure zirconium transform martensitically during rapid cooling at temperatures about 30° and 15°C re spectively below their To temperatures. Holden et al.2 determined M, temperatures of Ti-Cu alloys by a metallographic technique applied to isothermally treated samples. Their results, superposed on the McQuillan3 version of the partial Ti-Cu diagram are shown in Fig. 1. Sources of metals were: Titanium: Iodide bar; Foote Mineral Co. Ltd. Zirconium: Iodide bar; Foote Mineral Co. LM. Copper: Spectrographic Standard; Johnson Matthey and Co. Ltd. Alloys were prepared by levitation melting under argon to the following nominal compositions:* 0.5, Quenching, at rates to about 8000°C per sec, was performed by cooling in a stream of helium (99.999 pct pure) a 3/64 in. cube of material previously heated by a tungsten coil in a system operating at. 10-5 mm Hg. Cooling rates below 200°C per sec w were obtained by controlling the current to the heater coil. The specimen was supported on a 32 gage Pt, Pt-Rh thermocouple attached through a DC amplifier to an Edin magnetic oscillograph (Model 8082) with a maximum chart speed of 250 mm per sec. Transformation temperatures were read off the oscillograph charts at the location of the beginning of the thermal arrest. The same specimen was quenched several times, and all runs were repeated on new samples. Regular calibrations of the oscillograph against a potentiometer were made between quenching experiments. The criterion of martensite formation was the effect of surface rumpling. Previously polished samples that showed a rumpled surface after transformation are assumed to have undergone martens itic transformation: transformations of a diffusion type produce no surface disturbance, Figs. 2 and 3. Electrochemical measurements were made in a cell described elsewhere4 whose electrodes were the martensitic and the diffusion-transformed materials in the following electrolytes:

Jan 1, 1962

By Anthony Folger, Charles E. Straub

Kansas produced 38,150,878 bbl. of oil in 1928 and 40,658,170 bbl. in 1929, thereby retaining its rank as fourth among the oil-producing states of this country. Production for 1928 was less than that for 1927 (Fig. 1) because of a decrease in the number of completions, but the average initial production per well (Table 1) shows an increase due to the completion of wells of comparatively large capacity in the new Valley Center pool of Sedgwick County. This increase in average initial production per well was further augmented during 1929 by completion of additional wells of comparatively large capacity in the Valley Center pool and the new Greenwich pool of Sedgwick County. Production for 1929 exceeded that for 1928 and threatened to exceed all records except that of 1918, however, production was prorated in

Jan 1, 1930

By C. S. Barrett

W. Hofmann, J. Ziegler, and H. Hanemann—Having dealt with the same alloys in the winter 1941 to 1942, we want to give a short report on the generating of the hexagonal kappa phase by deforming the supersaturated alpha phase, which we then observed. This work was delivered as a Doctor of Engineering dissertation to the Technical University of Berlin by J. Ziegler in 1942. It still exists in two copies, somewhat damaged, a brief publication of it having been issued in Fiat-Review. Our work was started from the alloy Tombasil with 4.5 to 5 pct Si, 14.5 to 14 pct Zn, the rest Cu. Torpedo propellers were die cast from this alloy in Germany during the war. In order to improve this alloy, annealing was tried. By this treatment the alloy became at the same time harder and more brittle. A further research of this process was made in the Got-tingen University30 and the "Institut fÜr Metallkunde" of the Technical University of Berlin. It soon was apparent that the Cu-Si diagram at our disposal15,31,32 would not fit the observations. For this reason the pith of the matter became from then on the Cu-Si system. At that time we did not know of Smith's* and Andersen'sm latest diagrams. We first knew of them from Dr. Barrett's publication. Twenty-two alloys containing 2 to 11 pct Si were melted in a nitrogen atmosphere and generally homogenized for 2 to 4 hr at 800 °C. Part of the samples were then annealed at 700°, 600° and 500°. Annealing was followed by quenching in water. The phases corresponding to the various temperatures were identified by X-ray and microscopy. The Debye-Scherrer photographs generally were made of filings. The latter were produced after the last anneal of the samples, then equally annealed another 30 min in evacuated glass tubes and quenched in water. In the region of concentrations examined, the Cu-Si phases already known to us were observed: alpha, kappa (then called beta by us), gamma. By hot exposing an alloy of 7.69 pct Si at 800" and 750°,

Jan 1, 1951

By G. A. Reinhardt, H. J. Cutler

ThE Youngstown Sheet & Tube Co. has produced a large tonnage of 0.35 to 0.45 carbon forging steel, the acceptance of which was based on the physical properties of test specimens obtained by forging the original 5 3/4-in. (14.5 cm.) square bloom to a 3/4-in. (1.9 cm.) round. Annealed and tempered specimens were required. The test bars were annealed by heating from 900" to 950' C. and cooling slowly in mica. The test bars were tempered by heating to 825' to 875" C., quenching in water, and drawing to 515" to 535" C. Immediately after heat treatment, the test pieces were machined to a diameter of 0.534 in. (1.38 cm.) and tested. Very good physical properties were obtained and no difficulty was experienced in meeting the specifications called for. UlTimate Strength.. Elongation, Lb. pER Sq. In. PEE Cent.. in 4 In. Not LeEs Than Annealed specimens.............. 78,230 to 92,450. 18 Tempered...................... 120,000 to 149,350 9 After experience on this material, production of slightly higher carbon forging steel was started. The method of testing this material required that test blooms be either normalized or annealed. The normalizing consisted in heating to 850" to 900" C. and cooling in still air; the annealing, in heating to 850" to 900" C. and cooling in the furnace or in mica. From the treated bloom, the test pieces were taken either by core drilling or by sawing from points midway between the edges and the intersection of the diagonals. The cores or blocks were turned to a standard 2-in. test piece with a diameter of 0.564 in. and tested without further treatment. The physical requirements of the test pieces were: yield point, pounds per square inch minimum, 44,800; ultimate strength, pounds per square inch, 89,600 to 112,000; elongation, per cent. in 2 in. not less than 17. Difficulty was encountered as soon as work on this material was started. Many precautions and refinements were instituted but it was found very difficult to secure the required elongation.

Jan 1, 1920

By W. M. Lehrer

RECENT development of high-temperature brazing alloys has required information regarding the eutec-tic temperature and composition of the Pd-rich section of the Pd-B system.. Literature on this subject was found to be scanty with no complete system yet determined. Buddery and welch1 report an inter-metallic compound occurring in the Pd-B system at 6.33 wt pct B (PdsBz). Another source, Sieverts and Bruning,2 indicates that after annealing at 700°C, a 1.6 and a 2.0 wt pct B alloy were two phase whereas a 0.75 pct B alloy was single phase. Recent work3 using a hot-stage microscope has proposed a eutectic temperature of 743OC. This method utilized the observation of the onset of incipient melting at grain boundaries. The eutectic composition, however, was not determined. METHODS AND PR0CEDURES Five alloys were prepared by triple inert arc-melting high-purity palladium (95.98 pct) with additions of 2 to 6 pct purified amorphous boron. The alloys were crushed within a hardened steel mortar with a steel pestle. The 2 pct alloy, however, was too tough to be crushed in the above manner so was crushed by successive reductions through a rolling mill. Approximately 17 to 18 g of the crushed alloy was used in the thermal analysis. The alloys were melted in pure quartz crucibles. The thermocouple protection tubes were also of quartz and fused along the inside wall of crucibles to prevent floating of the thermocouple. This was an expediency as centering of the thermocouple in the melt would have been preferable. Melting was done in a tube furnace with a slow flow of tank helium maintained as a protective atmosphere. Heating and cooling rates were maintained at 3.5OC per min through the critical temperature ranges by means of a synchronous motor hook-up to a furnace controller. All specimens were heated to 100°C over the indicated liquidus on heating prior to reversing to the cooling cycle. Specimens emerged from the furnace with mirrorlike brightness attesting to the protective quality of the helium atmosphere. Thermal arrests were detected by the differential thermocouple technique using chrome l-alumel couples and nickel as the reference specimen. Arrests were recorded on a Leeds-Northrup automatic X-Y recorder. The specimen temperature and temperature difference were read to + 7.5OC and ± 1.5OC, respectively. These readings were well within the sensitivity of the instrument amplifier. Chromel-alumel couples were used in lieu of Pt-Rh as very few arrests were contemplated in excess of 1200" to 1300°C, the approach of instability. No standardization was performed on these thermocouples subsequent to their use. RESULTS The thermal arrest temperatures obtained are plotted in Fig. 1 as a function of wt pct B. The composition function was obtained by chemical analysis of portions of the specimens after the thermal analysis was completed. The 2 to 6 pct nominal alloys were found to have 1.80, 2.35, 3.65, 4.18 and 5.90

Jan 1, 1960

By J. A. Reeves

The unit-train for moving mineral raw materials is considered by many railroad men as the most significant contribution toward reducing rail freight costs since the introduction of the diesel locomotive. The idea, which involves assigning railroad equipment to only one haul and keeping the equipment rolling, results in the maximum utilization of equipment. For example, before the unit train was placed in service on coal hauled to one of Mid-Continent Coal and Coke Company's customers, about 900 cars and 9 locomotives were needed to move its coal requirements, compared with 250 cars and 6 locomotives currently used. If unit-train economics are to be achieved, coal companies cannot use railroad cars as small storage bins on wheels to accumulate their coal in train-load shipments, instead, these companies must build large bins which incorporate facilities for the rapid loading of railroad cars in a minimum length of time.

Jan 1, 1970

WALLACE E. PRATT, Wichita Falls, Tex. (written discussion *).-The age of the oil in the southern Oklahoma fields, Mr. Powers concludes, is Pennsylvanian, or in part, possibly, pre-Pennsylvanian. In a later paper,1 he recognizes the Ordovician age of the small production from the Bullhead A. Daney, No. 14, in the Healdton field. But nowhere does Mr. Powers admit the possibility of oil of Permian age in southern Oklahoma. Yet shallow oil in the adjacent north Texas fields. (Electra, Burkburnett, and Petrolia), which are generally conceded to be closely related to the fields of southern Oklahoma in geological aspect, may very well be of Permian age. Dr. Udden has already discussed this question,2 noting the organic nature of the limestone, outcropping near Electra, together with other evidence that organic material was present if not abundant, originally, in Permian rocks: The Permian rocks in north

Jan 3, 1918

By J. L. Wyatt

THE strain sensitivity, K, a property of metals defined as the unit change in electrical resistance per unit strain, was measured for commercial purity titanium wire to determine its usefulness as a strain gage material. A Kelvin double bridge, accurate to 0.000001 ohm, was used to make measurements from 0 to 1 pct total strain. A positive value of 0.17 for K was found. This compares with 2.15 for constantan and 3.5 for cold-worked invar, two of the more common strain gage materials. The effect of temperature also was determined. It was found that a change in temperature of 30°F caused the same resistance change as 1 pct strain. It is therefore concluded that titanium would have utility as a strain gage only if the thermal fluctuations in the specimen could be controlled to a high degree and in applications of very large total strain.

Jan 1, 1953

Department of Forestry and Geological Development, 435 State Capitol, Atlanta, Ga. S W. McCalhe, State Geologist. A complete list of Bulletins of the Geological Survey of Georgia will be sent upon request. Forty-five Bulletins have been issued, most of which deal with the mineral deposits of the state and are still available; they may be had on payment of postage. The subject matter of those bulletins of most interest is indicated in the following list, with the year of issue and the mailing weight. Bulletin 1, Marbles (1894), 3 lb , 8, Road building materials (1901), 3 lb , 9, Granites and gneisses (1902), 2 lb ; 10, Iron ores (1900), 2 lb , 11, Bauxite (1904), 2 lb.; 12, Coal deposits (1904), 2 lb ; 13, Ocher deposits (1906), 2 lb.; 14, Manganese deposits (1908), 2 lb ; 17, Fossil iron ore (1908), 2 lb.; 18, Clay deposits

Jan 1, 1933

A SERIES of awards for men and women in indus-try who by their inventions, heroisms, vision, and powers of mediation are contributing daily to the life and well-being of America in a substantial way, will be given by the Harmon Foundation. The series, to be known as "Awards to Honor Men in Industry," consists of two cash prizes, $1,000 and $500 each, accompanied by a gold and silver medal respectively, and 100 bronze medals. No one above the rank of foreman will be eligible. Because of the diversity of .American indus-try, the Foundation is planning to confine its awards during the first year to the following branches of man-ufacturing: automotive, building, electrical, metal and textiles, including clothing. The Harmon Foundation invites the general public, newspapers, organizations and employees to bring to its attention such persons as they may deem worthy of the award.

Jan 3, 1928

By D. W. Fuerstenau

The United States is rapidly approaching an acute shortage of minerals. According to some observers, this situation may even be more severe than the energy crisis because the US consumes nearly 30% of the world's mineral production. With the mounting competition for world mineral supplies, we can no longer take for granted that foreign mineral products will be available to the US as abundantly as in the past. In 1973, US consumption of mineral raw materials was $35 billion. Of this, $7 billion consisted of imports. Without a drastic reorientation towards the mining of domestic mineral resources, the 1973 $7 billion deficit might mushroom to $100 billion by the year 2000. Thus, a return to domestic sources of raw materials will become absolutely necessary-and will be bucking the trend of the past 25 years, characterized by capital investment for growth in multinational overseas mining operations.

Jan 11, 1975

By Rafael Errazuriz

About eighty miles north of the city of Antofagasta, Chile, located just below the Tropic of Capricorn, there spreads a wide desert area where copper oxide outcrops can be seen with the naked eye. Numerous old mining works and dump heaps with the green of atacamite and chrisocolla shining in the blazing sun, attest to the work done by miners in the beginning of this century. The dry desert air preserves the footstep marks, paths and trails of old cartwheels from years back. The mining area known as Michilla and Panizos Blancos, is located on the high plateau at 3000 ft above sea level. Around 1920 a Bleichert ropeway was built, which carried ores from the best known mine to a wharf at the Michilla bay. High grade silicious ores were shipped to the Gatico Smelter further north or to smelters in the United States or Japan.

Jan 8, 1973

PROGRESS IN DRILLING tungsten-carbide bits, lighter pneumatic drills, bonus plans, and alloy steels are discussed at northwestern gathering.

Jan 3, 1951

Schedule of Events

Jan 8, 1950

By V. F. Zackay, J. F. Carlson

CURRENT experimental work on the development of gas turbine engines in the automobile industry has emphasized the need for a relatively low cost nonstrategic castable alloy for service in the 1200" to 1400°F temperature range. Ferritic steels

Jan 1, 1956

By A. J. Zinkl

A two-year test led to adoption of carbide insert bits at the Iron King mine. Results: greater production, lower costs, and happier miners.

Jan 4, 1951

Jan 1, 1967

By Eugene J. Schreiber, F. Newton Parks

Booz-Allen & Hamilton management consultants has recently completed a comprehensive study of Brazil's minerals and metals sectors for 40 leading international and Brazilian companies. The 220-page study describes the activities and Investments under way in 25 key commodities and assesses the current state of Brazil's economy, the impact on domestic minerals and metals industries, and government minerals policies.

Jan 12, 1977

By R. C. Jensen

Jan 1, 1985