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By Deborah A. Spotts

Researchers at the Bureau of Mines have developed a technique for re- generating chromic acid-sulfuric acid etching solutions used in metal surface treatment operations. The technique utilizes a diaphragm cell equipped with a cation-selective membrane to oxidize cr3+ to cr6+ at the anode and to remove copper, the major metallic contaminant, at the cathode. Normally, spent etchant is discarded after approximately 3 days of use. Using the electrolytic cell, the etchant can be used for a year without replacement, From data obtained from industrial-scale cells, the installation of a regeneration cell with a 1,000-gal catholyte- holding tank has been estimated to save at least $240 per day, The payback period for the investment is estimated to be about 10 mo or less. Because the magnitude of these cost savings will vary at different locations, several graphs are presented to aid in calculating payback for a specific site. Using these graphs and the capital costs presented in this study, the payback period can be determined for installing a regeneration cell with a 500- or a 1,000-gal catholyte-holding tank in an existing surface treatment plant.

Jan 1, 1983

By Donald J. Barnes

The Glacier View RARE Ii further planning area contains no identified mineral deposits, other than stone, which cannot compete favorably with similar deposits closer to major markets. Pierce County mining claim records show six coal claims were located in the study area between 190b and 1907; however, no coal was found at the described locations. Two coal prospects, the H.O. Lamming and Floyd Rice, are within 0.5 mi (0.8 km) of the area's west boundary (fig. 1). At these prospects, impure bituminous coal beds strike approximately north and dip east toward the study area. Analyses of samples 1/ indicated an average heating value of 2,767 BTU 2/ per pound (6,436 joules per kg). Because of the low heat value, this coal is subeconomic. Intense folding and faulting which disrupted the beds would limit the use of conventional coal mining equipment, making future economic development even less likely. Trinity Resources of Houston, Texas has leased approximately 1,404 acres (568 ha) inside the study area and an additional 1,020 acres (413 ha) adjacent to the study area for oil and gas exploration. However, no oil or gas wells are known to have been drilled in or around the study area.

Jan 1, 1983

By J. W. Walkiewicz

The Bureau of Mines investigated alloys containing lanthanum (La), praseodymium (Pr), neodymium (Nd), cobalt (Co), copper (Cu), iron (Fe), and magnesium (4g) as possible components of a permanent magnet mate¬rial utilizing a cerium-free synthetic mischmetal (M) as a substitute for scarce samarium (Sm) metal. Magnets containing M-Co-Cu-Mg and M-Co-Cu-Fe-Mg were fabricated by powder metallurgy techniques and evaluated. A synthetic mischmetal (M20) containing 20 pct La, 60 Pr, and 20 Nd yielded the best overall magnetic properties. The M20-Co-Cu-Mg alloys had energy products as high as 13.2 MGOe, remanences as high as 7.89 kG, normal coercivities as high as 6.26 kOe, and intrinsic coercivities as high as 13.4 kOe. The best value of intrinsic coercivity, 22.9 kOe, was obtained with an M-Co-Cu-Mg magnet in which the synthetic misch¬metal contained 30 pct La, 50 Pr, and 20 Nd. These values compare favorably with those of the Sm-Co magnets fabricated and measured at the Bureau's Reno Research Center, which had energy product of 15.1 MGOe, remanence of 7.8 kG, normal coercivity of 7.5 kOe, and intrinsic coercivity of 27.4 kOe. Iron substitution for part of the cobalt resulted in a decrease of magnetic properties, although several percent iron can be added before a drastic loss of magnetic properties occurs.

Jan 1, 1983

By P. J. Dallimore

The Bureau of Mines has calculated general time-dependent solutions for radon diffusion from cylindrical and slab rock samples containing uniform radium distribution. Results have been obtained for several sets of boundary conditions. The method is suitable for determining the effective diffusion coefficient and the effective porosity for radon.

Jan 1, 1983

By P. A. Rey

Water recycle is an important part of the coal preparation process. This study was directed toward: (1) a survey of current practice and an evaluation of both the solid and liquid components of blackwater, (2) an experimental study of blackwater flocculation, and (3) a fundamental analysis of the flocculation process. The solids contained in the blackwater discharge to the fine refuse thickener of a coal preparation plant were found to contain, on average, 56% coal and 44% mineral matter. The mineral matter was largely illitic clay, while the water phase contained relatively large amounts of S04 and Ca++. Detailed studies were made of both natural and synthetic flocculants and the influence of polymer type and pH on the settling rate, turbidity of the supernatent liquid and sludge volume of the settled solids. More tundamental studies were made that clearly indicate the need for controlled mixing of polymer into the suspension to be flocculated, and the need to evaluate, more closely, the structure of the flocs formed during the process. Research recommendations are given.

Jan 1, 1983

By E. Chin

The only economically significant mineral exploited in Banglades - during 1981 was natural gas. Nitrogenous fertilizer production was important to the agricultural sector and was totally dependent on the natural gas for fuel and raw material. Domestic cement plants were also fu pled by natural gas. The flat river-delta terrain for most of Bangladesh makes the potential for discovering major mineral deposits poor. No large deposits of metal ores have been found and only in the small hilly southeastern section of the country is there even much chance of finding any. Heavy mineral sand deposits may eventually be exploited along the Chittagong coastline. There is a good potential for crude oil discoveries. The Bangladesh economy has been heavi¬ly subsidized by billions of dollars of foreign aid since the country's inception. A World Bank report recommended total aid needs of over $2.6 billion in fiscal year (FY) 1980-81. It received commitments for barely over one-half that amount.

Jan 1, 1983

By Stephen R. Iverson

Mineral deposits examined in and near the Raywood Flats RARE II area have low potential for development. The Mill Creek Mine (fig. 1), has produced about 14,000 tons (13,000 t) of marble, and another 5.5 million tons (5.0 million t) of marginal marble reserves suitable for lime, chemicals, and cement production are estimated to remain at this deposit. However, nearly all the marble is outside the study area. The deposit is marginal because alternate sources of marble are closer to markets. A tungsten occurrence in the marble is too small and low grade to be considered a resource. Ten tons (9.1 t) of uranium- and thorium-bearing material have been mined from a pegmatite dike at the St. Patrick Mine. However, this occurrence also is too small and low grade to be considered a resource. More than 400 lode and placer claims have been located in or near the study area. There are no current claims or mineral, oil and gas or geothermal leases.

Jan 1, 1983

By D. C. Fleck

The Bureau of Mines, in a cooperative research program with four lead companies, has investigated ferric chloride leaching of galena to prepare lead chloride for molten-salt electrowinning to produce lead metal. The hydrometallurgical-electrolytic process is an alternative to the sintering-smelting-refining process currently used to produce lead metal and avoids the environmental problems associated with a conventional smelter. During investigations on the electrowinning aspects of the work, it was noted that certain cations, moisture, and sulfate in the electrolyte affect lead metal purity, cell voltage, current efficiency, and viscosity of the electrolyte. Results of bench-scale tests are re-ported on the effects of CaCI2, CuCI2, FeCI2, MgCI2, NaCI, ZnCI2, PbS04, and moisture on electrolysis. As impurities increased in the electrolyte, current efficiency decreased. CaCI2, CuCI2, and FeC12 decreased current efficiency by 12 to 47 pct. ZnCl2 gave a small voltage increase, while CaCI2 addition equivalent to 4.9 pct Ca caused a 50-pet increase in voltage. The lead metal was contaminated in direct proportion to the CuCI2 buildup in the electrolyte, Anode corrosion was observed with MgCI2 and MgC12?6H20. Viscosity increased appreciably with the buildup of NaCI, CaCI2, and sulfate. Electrolyte foaming occurred with ZnC12, MgC12?6H20, MgC12, FeC12?2H20, and FeCI2. Moisture inhibited the coalescence of the lead metal.

Jan 1, 1983

By Lawrence L. Davis

This chapter includes tables for 1981 that were not available in time for publication of the 1981 Minerals Yearbook, but does not include corresponding tables for 1982. The value of raw nonfuel minerals produced in the United States during 1982 was estimated at about $20 billion, a decrease of $5 billion compared with that of 1981. The decline in value is the first since 1971 and is the largest percentage drop since 1938. Although the domestic mining industry continued to be troubled by difficulties in attracting capital and by import competition from countries with lower overall production costs, the principal cause of the decline was sharply decreased demand brought on by the worldwide economic slowdown. Metal commodities were impacted most severely with only 4 of 21 metals registering production value gains and only 3 of 21 showing production quantity increases. Overall metal production value decreased 37% from that of 1981, a reflection of the domestic slowdown in the automobile and construction industries, which are major metal users, Overall production value of nonmetals decreased 12% compared with that of 1981, with only 14 out of 44 nonmetals showing increases. Nonmetal production quantities increased over 1981 for only 6 of the 44 nonmetals.

Jan 1, 1983

By Paul C. Hyndman

No minerals have been produced from the McGraw Creek RARE II area. During the 1982 U.S. Bureau of Mines study, there were no active mines in the area. Limestone occurrences (fig. 1, no. 2), four copper prospects (fig. 1, no. 1, 4, 5, 6), and a prospect with no significant mineral values (fig. 1, no. 3) were examined. A moderate potential for high-calcium limestone resources was estimated between ocurrences within the study area near McGraw and Spring Creeks (fig. 1, no. 2). There is low potential for copper resources at the Argenta Prospect (fig. 1., no. 1) in the study area, and the McDougall Prospect adjacent to the area.

Jan 1, 1983

By Harry W. Campbell

U.S. Bureau of Mines investigation; identified no mineral resources or evidence of mining activity in the Sheep Divide RARE II area. A deposit 10 mi (16 km) southwest of the area contains copper and silver minerals in the Triassic Wild Sheep Creek Formation which probably underlies basalt lava flows covering the study area. Abundant basalt in the area can be crushed and used as aggregate, but suitable deposits closer to markets are widely available No sand, gravel, coal, oil, gas, or geothermal resource, were Identified. INTRODUCTION Location and Access The Sheep Divide RARE II area [10 mi (16 km) west of the Snake River] encompasses 7,100 acres (2,800 ha) of the Hells Canyon National Recreation Area in the Wallowa-Whitman National Forest. Enterprise, Oregon, is located 23 air mi (37 (m) west of the area. Peripheral access is provided by the highway from Joseph to the community of Imnaha, Oregon, then south to the study area by the graveled Upper Imnaha Road (fig. 1).

Jan 1, 1983

By Laurel A. Powers

The Bureau of Mines process for recovering Ni and Co from low-grade domestic laterites uses a reduction roast followed by an ammonia, ammo-nium sulfate leach. This investigation examined the waste streams of the process for their potential environmental impact and focused on the laterite residue produced. The U.S. Environmental Protection Agency's extraction procedure (EP) toxicity tests and column leaching showed that leachable metal concentrations would be low enough so that the residue would not be considered a hazardous waste under present definitions. Under nonacid leaching conditions, about the same amount of metal was extracted from laterites as from their residues, and the leachates were similar to water samples from an undisturbed laterite deposit. Washing tests on the laterite residue showed that ammonia and ammonium sulfate concentrations were reduced according to equilibrium stage calculations, resulting in residues that would be acceptable for revegetation. With water washing only, the residue would not be considered a hazardous waste even though significant amounts of Ni and Co were absorbed from entrained leach solution onto the residue. Washing first with fresh leach solution and then with water prevented this absorption and thus improved the overall metal recovery.

Jan 1, 1983

By Jeffrey H. Welsh

The Bureau of Mines studied the use of computerized, continuous, remote monitoring systems for safety from power system faults in underground coal mines. In this report the need to improve protection against power system faults is documented, and types of faults are identified. The relationship between mine safety regulations and computerized, continuous, remote monitoring is analyzed.

Jan 1, 1983

By James D. Eklund

Towards the goal of improving safety, economy and efficiency of scaling in underground metal/nonmetal mines, Battelle developed a combination prying/hammering scaling tool. A prototype was subjected to limited testing 1) to verify its operational functions and 2) to assess its potential capability in future underground testing.

Jan 1, 1983

By Bruce D. Hanson

The Bureau of Mines conducted a series of ignition tests with two types of conical bits (plumb bob and pencil) used on continuous mining machines, to determine their ignition potential at various bit speeds, cut depths, and wear conditions. The tests were conducted using single bits mounted on a 34-in-diam drum in a Bureau ignition test facility. The bits impacted blocks of Berea sandstone in a 6.5 pet methane atmosphere at various bit speeds and cut depths. In a new condition, the plumb bob bits were considerably more incendive than the pencil bits, causing ignitions in 32 of 35 tests at 60 rpm, compared with ignitiolls in 2 of 22 tests for the pencil bits. The results from new bit testing also show that reduction of bit tip velocity to 180 fpm does not eliminate ignition potential. When subjected to progressive wear, bits of both types were more incendive when they were locked in place, unable to rotate, than when they were free to rotate.

Jan 1, 1983

By Robert J. Timko

Because of leakage through and around permanent stoppings in underground mines, more air must be forced into a mine than would otherwise be required for ventilation. As power costs increase, costs resulting from air leakage add increasingly to the operating costs of mining. The Bureau of Mines evaluated four different stopping construction techniques based on the ideas that (1) airtightness could be enhanced by brushing rather than troweling on mortar sealant and that (2) modified mortars (mortars containing glass fibers and other additives for increased strength and adhesion) would improve sealing performance. Air leakage tests comparing conventional to modified stoppings were done when the stoppings were built, after 6 months, after 1 yr, and following simple maintenance. It was found that stoppings can be built and maintained better if-- The area where a stopping is to be built is properly prepared. Stoppings are constructed using the techniques devised by the Bureau. Stoppings are periodically examined for leaks. Stoppings found to be leaking, especially at the perimeters, are resealed.

Jan 1, 1983

By W. R. Byrnes

This project was initiated on October 1, 1980 and will be completed on December 31, 1983. The project was Initially approved and funded by the Office of Surface Mining and subsequently was moved to the jurisdiction of the Bureau of Mines. It was administered through the Indiana Mining and Mineral Resources Research Institute. The research was done to assess reforestation success and ultimate productivity for areas reclaimed under the Surface Mining Control and Reclamation Act of 1977 (P.L. 95-87). The Permanent Regulatory Program for implementation of P.L. 95-87 Includes provisions for revegetation that require seeding of ground cover plants to control erosion until permanent vegetation such as tree species Is established, and restoration of mined land to its original or better productivity. Much of the land to be surface-mined presently supports forest cover and it is anticipated that reconstructed minesoils will exhibit high productive potential for hardwood tree species. Hence, information was needed on compatibility of ground cover and tree seedlings when established concurrently as well as on revegetation success under postmining versus premining conditions.

Jan 1, 1983

By Frank E. Chase

Kettlebottoms are columnar masses of rock--the preserved casts of ancient tree stumps--embedded in coal mine roof strata (of which they are a part). Because unsupported kettlebottoms can detach from a mine roof without warning, they are a hazard to miners. The primary objectives of this investigation were (1) to better define and describe kettlebottoms and (2) to evaluate kettlebottom support techniques in terms of safety and effectiveness. A telephone survey of mine operators, interviews with Mine Safety and Health Administration (MSHA) personnel, and underground mine visits were conducted in Pennsylvania, West Virginia, and Kentucky. Information gathered during this investigation indicates that the size and frequency of kettlebottoms in mine roof are dependent upon past geologic events and biological processes active during the deposition of roof sediments. To ensure the safety of mine personnel, all undermined kettlebottoms should be supported. The roof should be bolted next to kettlebottoms less than 3 ft in diameter, close enough to allow a portion of a wood or steel header to be extended beneath each kettlebottom for support. Two bolts and a wood plank or steel strap should be employed to support kettlebottoms over 3 ft in diameter.

Jan 1, 1983

By W. W. Simpson

The Bureau of Mines conducted research to determine the effects of potassium trithiocarbonate (KTTC), a degradation product of potassium ethylxanthate (KEX), on flotation of chalcopyrite and molybdenite. Small amounts of KTTC were identified in fresh and aged solutions of KEX using thin-layer chromotography. Hallimond tube flotation tests on pure minerals showed that KTTC acts as a weak collector for chalcopyrite. Both KEX and KTTC tend to depress molybdenite, but the depression effect is easily overcome by addition of a small quantity of fuel oil. The results of the Hallimond tube tests were confirmed in batch flotation tests using a porphyry copper ore.

Jan 1, 1983

Lower noise exposure levels for operators and cleanup personnel working in portable nonmetallic mineral crushing and screening plants.

Jan 1, 1983