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By Terry R. Neumann

In 1989, the Bureau of Mines conducted a mineral resource investigation of the 52,350-acre Jersey Jack study area, located in the Clearwater Mountains of north-central Idaho. Twenty-eight mines and prospects were examined, and 483 rock, placer, and petrographic samples were collected during the field study. Two properties contain gold resources; mining company data show the Robinson Dike mine contains an estimated 940,000 tons of "drill proven and probable reserves" averaging 0.041 oz/ton gold, and the Bureau of Mines investigation showed the Blacksand placer mine contains an estimated 64,000 cubic yards of identified placer resources averaging $8.13 in gold per cubic yard. Sample analyses from other properties indicate that gold resources are likely to exist; however the low tonnage, narrow, fissure-vein type deposits would require mining by relatively high-cost underground methods and would be subeconomic at a gold price of $400/oz.

Jan 1, 1991

By W. C. Hagel, H. J. Beattle

DURING an earlier examination of high-temperature alloy, A-286, the presence of an unknown intermetallic compound was verified by X-ray diffraction. Owing to its prominent appearance at grain boundaries, the arbitrary name of G phase was assigned.' Low-silicon, vacuum-melted heats were found to contain no G phase, and this investigation was initiated to determine the influence of silicon on G-phase formation; additional work was undertaken to extend existing data on other intermetallic compounds and the aging reactions in this group of alloys. Taylor and Floyd2-4 observed that the Ni3Al phase (y') and the Ni8Ti phase (7)) are the only equilibrium intermetailic compounds in nickel ternary alloys containing up to 25 pct Cr and 10 pct Ti or Al. They found that y' can dissolve considerable nickel, chromium, and titanium, although the stoichio-metric composition of 7 remains fixed. Nordheim and Grant5 confirmed that age hardening of 80 pct Ni-20 pct Cr alloys of the Nimonic-80 type is due to precipitation of y', where aluminum is partially replaced by titanium. They suggest that optimum hardness and ductility result from increasing the titanium to aluminum ratio toward the end of the y' solubility range and from increasing total titanium and aluminum content to the maximum limit permitted by processing. Such information is necessary for those seeking to improve the service-temperature range and long-time structural stability of high-temperature components. Experimental Methods Compositions of materiais studied. are listed in Table I. Alloys D, E, and F possess representative A-286 analyses; silicon increases from less than 0.02 to 1.75 pct in alloys A to H; in alloys I to K, titanium decreases from 2.24 to 0.39 pct, and aluminum increases from 0.1 6 to 240 pct. Alloys A and D were solution heat treated for 4 hr at 1700°F, oil quenched and aged for 0.5, 2, 6, 12, 30, 70, 200, and 1000 hr at 1200°, 1300°, 1400°, and 1500°F. Therefore, a total of 33 specimens was required for each

Jan 1, 1958

By A. F. Colombo, R. T. Sorensen, D. W. Frommer

The Bureau of Mines developed a flotation method for concentrating spiral tailing produced from pilot plant tests on the Champion mine ore fines . The feed material contained about 49 percent Fe and 15 percent SiO2 and was posed mostly of specular hematite , muscovite , and chlorite . Bench- scale , batch flotation research developed a reagent suite composed of tall oil - fatty acid , fuel oil , sulfuric acid , sodium fluoride , and sodium silicate for recovery of iron minerals in the froth product . Concentrate made with the reagent suite contained 87.3 percent of the iron and analyzed 65.6 percent Fe and 1.9 percent SiO2 . Continuous flotation tests were made with a nominal feed rate of 400 lb /hr , but without middling recirculation . Using nearly the same amount and complement of reagents as in the batch tests , three similar continuous tests gave concentrates averaging 63.9 percent Fe and 3.1 percent Sio while recovering about 86 percent of the iron .

Jan 1, 1964

By F. A. Penning

An experimental and analytical investigation was conducted on a recoverable pit bottom buffer. Work was conducted at the Colorado School of Mines using the U.S. Bureau of Mine-s free fall test tower. The four-sided butter, one of several designs by Cable Belt Ltd., was constructed of reinforced rubber slabs. The kinetic energy of falling weights, 1670 to 6000 lb, was absorbed by the flexure of rubber slabs loaded along their edge. A series of constant energy, 3000 ft-lb and maximum design velocity, 600 fpm tests were conducted. Static testing of the buffer established the load-deformation behavior. A large hysteresis loop plotted above and below the data published by the manufacturer. Creep was evident during; the loading Lend unloading cycle. Electronic instrumentation measured deceleration using your accelerometers; overall and intermediate movement was found from four displacement transducers; bending strains were recorded at four locations; and base reactions were measured by using four load cells. Data were recorded on tape and played back on a recording oscillograph. High speed movies were taken of all the tests. Symmetry of response and rebounds, when they occurred, were noted. From the displacement-time and load-time data, maximum decelerations were calculated by four methods and different assumptions. Good agreement was found from these approaches. Impact loads ranged from a low of 0.7 to a high of 6.1 gs. A dynamic computer model was written for the response of the buffer. Displacement-time, and acceleration-time plots show close correspondence with experimental data for the ten experiments. Data from accelerometers, displacement transducers, strain gages, and load cells are included. The computer program listing, and displacement-time acceleration-time plots are also presented.

Jan 1, 1980

By D. Goossens

Quality control is a system which should guarantee that quality is achieved. It is the execution and verification of a project in an organised way, in order to obtain the maximum of certainty that the results meet the requirements. This concerns all stages of the project, from the soil investigation, over the design, to the execution. Quality control can and has been successfully realised for important projects by means of a quality plan. A quality plan is based on a number of general considerations, but should certainly be focussed on the particularities of a specific project. Practical examples of quality plans, which have been realised on sites in Belgium, are developed and the advantage of the system is shown by concrete case studies.

Jan 1, 1996

By M. L. Fenger

This report describes a study of the factors which affect medium voltage (661 - 1000 volts) and high voltage (1001 - 7500 volts) trailing cable couplers for use in underground coal mines to connect trailing rabies. Improvements in quality, dependability, and safety of medium and high voltage couplers are presented in the form of requirements for couplers. The results of an investigation of high voltage trailing cable coupler design and of whether trailing cable couplers must have a metallic shell as required by CFR 30 part 75.805 are presented. Conclusions and recommended research programs are included that describe the present situation and future development approaches.

Jan 1, 1978

By M. Tomono

Harima Works is operating as the zinc and lead simultaneous smelter utilizing the imperial Smelting Process. The smelter commenced its operation in 1966 with designed capacities of 3500 t/M of zinc and 1500 t/M of lead. After that, owing to the results of progressive developments and improvements in operating efficiency and equipments, it has doubled its production figure. This report reviews our recent developments carried out from 1983 to 1985. Firstly, the furnace bottom design was modified for the purpose of reducing carbon consumption ratio. As a result, shaft operating condition has been satisfactory and carbon consumption ratio was improved by 2%, in addition, furnace zinc production was increased by about 8%. Secondly, the oxygen enriched operation at sintering machine was tested from July 1984 to June 1985, in order to increase the sinter productivity, and to solve the capacity imbalance between sinter plant and ISF. As the test result, it was found out that sulfur elimination rate was increased by approx 10% with the oxygen enrichment of 500 Nm3/hr.

Jan 1, 1986

By J. P. Powell

Systematic waterflooding was first tried in Washington County, Okla., in 1937, when a 40-acre project was begun in secs. 24, 29, 32, and 33, T. 27 N., R. 13 E., jointly by the Keener Oil Co. and the Phillips Petroleum Co. The property later was sold to Lee Morrison. A second project was begun in 1941 in sec. 14, T. 6 N., R. 12 E., by the Oklahoma Oil Corp. Both projects were abandoned by the end of 1942. A third project was begun in 1945 and the fourth in 1948, but 1949 actually was the beginning of intensive waterflooding development in Washington County. The results of previous waterflooding projects are described in Bureau of Mines Reports of Investigations.2 3 4/ Oil production in the county followed a similar trend, dropping to a low of 990,000 barrels in 1945, then steadily increasing until 1956, when more than 4 mil-lion barrels of oil was produced. Most of the increase in oil production is directly attributable to water injection.

Jan 1, 1957

By P. N. Anyalebechi

The effects of solidification rate (0.4-26.1 K/s) and alloying elements on the cast microstructures of aluminum alloy 5182 have been investigated with directionally cooled laboratory-size ingots. The alloying elements examined included Mg (3.6-4.7 wt.%), Mn (0.35-0.75 wt.%), Fe (0.11- 0.42 wt.%), Cu (0.03-0.25 wt.%), and Si (0.11-0.28 wt.%). These reflect the chemical compositions of AA 5182 end stocks with high recycled used beverage container (UBC) content. For a given chemical composition, the average dendrite cell and constituent phase particle size decreased with increase in average solidification rate. In general, within the level investigated, Mg did not have a significant effect on the types, volume fractions, and average sizes of the constituent phase particles. However, increase in Mn, Si, Fe, and Cu increased average sizes and volume fractions of the constituent phase particles.

Jan 1, 2010

By Kent W. Hawley

An improved visibility system was developed for use on the large (100 ton+) haulage trucks typically operated in open pit and surface mines. The improved visibility system provides the truck driver' with a means of viewing hazardous situations that occur in the extensive blind areas adjacent to his true. The cost effective, reliable, visibility system consists of a closed-circuit television three unique fresnel viewers, and two improved mirrors. This report describes the visibility problems of Large trucks in the surface mining environment, shows the performance of existing mirrors, substantiates concept selection, and describes the prototype improved visibility system.

Jan 1, 1978

By R. Mensah-Biney

The adsorption of gold-thiourea complex onto a cation exchange resin, Amberlite 252, has been evaluated in a batch stirred reactor. The observed non equilibrium saturation capacity was 3.20 meg Au/g dry resin (620 kg/t) whereas the equilibrium ion exchange capacity was only 0.53 meq/g (103 kg/t). The enthalpy of adsorption was 4 -25 kJ/mole under equilibrium conditions and increased to 20-200 kJ/mole under non equilibrium conditions. Under non equilibrium conditions, the adsorption capacity of the resin decreased with increasing temperature and increasing thiourea concentration and increased with increasing gold concentration. This dependence of adsorption capacity on thiourea concentration and temperature may be a useful tool for elution of gold from the loaded resin. Scanning electron microscopy revealed evidence of deposition of elemental gold on the loaded resin under non equilibrium conditions. The proposed mechanism for "adsorption" of gold-thiourea complex onto this cation exchange resin consists of an ion exchange reaction followed by a reduction of the exchanged gold complex to elemental gold on the surface of the resin.

Jan 1, 1997

By S Colak, M Tunc, C Celik, M. M. Kocakerim

The most important parameters affecting the solubility of ulexite (sodium calcium borate) in H2SO4 were found to be reaction temperature and solid:liquid ratio, in that order. Dissolution increased with increase in temperature and stirring speed and with decrease in solid:liquid ratio, particle size and acid concentration, the last effect as a result of decreased precipitation of CaSO4 on unreacted particles. Optimum conditions, in which around 99.5% of the ulexite could be dissolved, were a reaction temperature of 60 degrees C, a solid:liquid ratio of 1:8 g/ml, an acid concentration of 8 mol/l, particle size smaller than 425 micrometres, a stirring speed of 52.33/s, a reaction time of 1 800 s, a calcining time of 3 600 s and a calcining temperature of 170 degrees C. These conditions, determined by the Taguchi method, are reproducible in a commercial production environment

Jun 21, 1905

By R. H. Lien

The Bureau of Mines has conducted research on a flue gas desulfurization (FGD) process as part of its goal of minimizing the undesirable environmental impacts associated with sulfur dioxide (S02)-bearing waste gases. This FGD process, referred to as the modified citrate process, involves absorption of S02 in a buffered citric acid solution. The absorbed S02 is subsequently stripped from the solution using steam, which regenerates the solution and produces a wet S02 product. This product can be further processed to make sulfuric acid or liquid S02. Economic evaluations showed the process to be expensive when the stripper was operated at or near ambient pressures because of the large amounts of steam required for solution regeneration. Research was directed at reducing steam consumption in the stripper. The effect of stripper pressure on steam consumption was investigated. A process research unit (PRU) was operated with the stripper pressurized in the range of 5 to 150 psig. Test results showed that steam consumption decreased with increased stripper pressure. For example, when operating the PRU stripper at 150 psig, 4.1 grams of steam per gram of S02 was required to remove 90 pct of the S02 from a 1.0-vol-pct-S02 gas. This compares to 7.1 grams of steam per gram of S02 required for 90-pct S02 recovery at 5 psig.

Jan 1, 1982

By E. A. Mevissen

With the ever increasing consumption of mineral commodities, the vital question is not whether sufficient mineral quantities will be available, but rather can the known existing low grade resources be mined economically. Conventional conveyor systems are being used in some open pit mines to decrease haulage costs. n an effort, to take this concept one stop further, this contract study examines the use of a high angle conveying system in an open pit mine. It identifies available high angle conveying equipment and examines the haulage and crushing costs associated with both a conventional truck and shovel mining operation and a high angle conveyor operation. These costs analyses were performed on a hypothetical copper, taconite and phosphate mine. Information was gathered from a series of high angle conveying equipment and open pit mining operations in the U.S. Volume I includes a detailed review of the state-of-the-art in high angle conveying concepts, the, hypothetical mine development, and the cost analyses. Volume II includes the appendices.

Jan 1, 1981

By Gary A. Kingston

Low-cost hydroelectric energy in the Pacific Nortnwest has been an important factor in the development of a ferroalloy industry. Eleven companies, employing approximately 1,000 persons, produce about 116,000 tons (1954-58 average) annually of ferrosilicon, ferrochromium, ferromanganese, ferrophosphorus, silicomanganese, and ferronickel. About 7,500 tons (1954-58 average) of these ferroalloys is consumed in the Pacific Northwest States of Washington and Oregon; the rest is used principally in other western and mid-western markets. In 1959, the Bureau of Mines began a study to determine the current status and to evaluate the potential of the ferroalloy industry in the Pacific Northwest. The Bureau gathered information from operating alloy plants in Oregon, Washington, Idaho, and Montana; from published materials; and from consumers of ferroalloys.

Jan 1, 1962

By Lauricella P. F, Hendri D

In the Mesel sediment-hosted disseminated gold deposit, the spatial distribution of hydrothermal alteration is controlled by steeply dipping faults and shallowly dipping lithologies. Hydrothermal alteration of carbonate rock is characterised by decalcification, dolomitisation and silicification. Intense argillic alteration occurs in a laccolithic andesite intrusion adjacent to decalcified and silicified carbonate units. Sulphide minerals (pyrite, realgar, orpiment, stibnite and cinnabar) accompany hydrothermal alteration and precious metal mineralisation. The trace elements Ag, As, Sb and Hg are zoned spatially throughout the deposit. Mesel contains a mineable gold reserve of 7.8 million tonnes at 7.3 g/t Au. Gold mineralisation is preferentially localised in carbonate rocks adjacent to and beneath the andesite intrusion. The ore body consists of a central, near-vertical, high grade "feeder" system flanked by tabular, inward dipping, moderate grade "ouflow" zones. Mineralisation is controlled predominantly by two steeply dipping faults with high grade (>10 g/t) gold zones centred about structural intersections and fault splays. Gold is submicron size and locked in very fine grained (

Jan 1, 1995

By M. Labrie, H. L. Gibson, G. Doiron, J. J. Watkins, D. H. Watkinson

The Corbet deposit is one of 17 proximal Cu-Zn massive sulfide deposits located. within the Noranda Cauldron which occurs within the core of the Noranda Volcanic Complex. The deposit is located at the top of the Havrian Formation, the lowermost formation of the 3000 m thick Mine Sequence; the deposit has Yielded 2.75 M tonnes of ore grading 3% Cu, 0.96% Zn, 2.06 g/t Ag and 1.0 g/t Au. The multi-lens Corbet deposit formed within a 250 m wide crater that occurs within a localized breccia pile. The Corbet breccia pile was constructed by explosive magmatic and hydrovolcanic eruptions localized along the south flank of a larger andesitic shield volcano that formed during the waning stages of Havrian volcanism. The breccia footwall of the deposit allowed unfocused and widespread hydrothermal discharge that resulted in the development of a large area of chlorite and fringing sericite alteration that exceeds, by six times, the size of the sulfide lenses and represents a significant exploration target.

Jan 1, 1993

By Robert T. MacMillan

An essentially chemical technique has been developed on a small scale for the efficient utilization of certain domestic titaniferous iron ores. Three main steps are involved: (1) Sintering the ore at 1,050° C. with carbon and soda ash to reduce the iron to metal powder, retaining the titania in the slag, (2) separating the powdered iron from the slag, after wet grinding, by magnetic or gravity methods, and (3) sulfuric-acid decomposition of the titania fraction to produce pigment and certain byproducts. The technique was first applied to the tailings from the Bureau of Mines bauxite-concentrating plant at Bauxite, Ark. A good grade of powdered iron was produced from this material. Subsequently, the work was diverted to the study of the titaniferous magnetite from the MacIntyre Mine at Tahawus, N.Y., because of the potentially higher recoveries of iron, titanium and vanadium. Ninety percent of the iron in this ore has been recovered as an iron powder analyzing 90 percent metallic iron and containing 2 to 3 percent TiO2. The remaining titania was found in the slag and was recovered as pigment-grade TiO2 by application of a suitable technique. The vanadium was distributed between the TiO2 fraction and the alkaline liquor resulting from the wet-grinding and magnetic-separation operations, with only a minor proportion retained by the metallic iron.

Jan 1, 1950

By L. M. Irwin

This Bureau of Mines investigation relates the physical properties of copper reverberatory furnace slags to changes in composition, The smelting of upper Michigan copper ore presents some problems that probably differ from those of other copper smelting areas. The study of these problems has, however, provided important data regarding slags in general and therefore will be of value to other operations as well. Conclusions reached from this study were: (1) Slag fluidity and refractive indices varied directly with the iron content and inversely with silica, lime, and alumina, and (2) there was no apparent correlation between slag fluidity and its copper content.

Jan 1, 1962

By G. R. Hopkins

One of the largest items in the expense of operating a refinery is the cost of the fuel used in distillation and for miscellaneous purposes such as in the heating of buildings and in the generation of electricity, On a B. t. u. basis, the average refinery consumes approximately one-tenth as much fuel as it produces. Theoretically, the fuel consumption at refineries should be much smaller than this, but furnaces can riot be designed to be 100 per cent efficient' and, in addition, a large part of the waste heat is low-temperature heat which would not pay for the expense of recovering it. Annual surveys of fuel consumption at refineries have been made by the United States Bureau of Mines, beginning with 1925. During the 5-year period, 1925-1929, the refineries made steady progress in fuel economy. This is evidenced by the Computed figures of heat requirement Per barrel of crude oil refined, which show a decline from 829,000 B. t. u. in 1925 to 639,000 B. t. u. in 1929 (see fig. 1). In 1930, however, the trend in fuel economy was reversed and the quantity of heat utilized in refining the average barrel of crude oil rose to 672,000 B. t. u. There were undoubtedly a number of reasons for the apparent decrease in fuel economy at refineries in 1930, chief of which were the tendency to carry the distillation farther instead of merely topping the crude and a gain in the consumption of waste oils, such as acid sludge, which in actual practice yield less heat per unit consumed than has been theoretically assigned to oil. The consumption of natural as fuel at refineries has declined since 1927, but this has been more than compensated by a rapid increase in the use of refinery or still gas. The total consumption of oil as refinery fuel in 1930 was not much below the 1925 total, but the consumption of coal has declined rapidly, so that in 1930 liquid and solid fuels contributed only 56 per cent of the total heat units- utilized at refineries as compared with 77 per cent in 1925 (see fig. 2).

Jan 1, 1931