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By Arden D. Fugate

This work was conducted to determine a feasible process for converting siliceous fluoride offgases to a commercially usable product. The offgases were generated by pyrohydrolytic defluorination of low-grade fluorspar in a gas-fired rotary kiln, and fluorine was collected as a hydrofluoric-fluosilicic acid. A silicon-free fluoride solution for further processing was then produced by neutralizing the acidic scrubber solution with anhydrous ammonia, silicon being separated as orthosilicic acid. Ninety to ninety-nine percent of the fluorine originally present remained in solution as ammonium fluoride. Silicon was also separated from synthetic fluosilicic acids, having F-to-Si weight ratios ranging from 3.50 to 14.3. The solutions below a ratio of 4.06, the F-to-Si ratio of H2SiF6, containing dissolved silicon were desiliconized as completely as those containing less than the stoichiometric quantity of silicon. An electrolytic-grade cryolite was recovered from the ammonium fluoride solution by reacting with either sodium aluminate or alumina trihydrate and sodium hydroxide. A product containing 97 to 100 percent of the fluorine, represented by Na3A1F6, was recovered, and 94 to 99 percent of the theoretical yield was realized.

Jan 1, 1963

By A. R. T. Denues

"INTRODUCTION The orienting phases of the current investigation of cushioned blasting in the Explosives Division of the Bureau of Mines were indicated in a previous publication (5) 3/. Pertinent literature reviewed therein indicated a highly controversial field. This emphasized the need for experimental studies of many factors that affect the health and safety of miners and the efficiency of mining operations. Results of some orienting tests showed marked effects on practical hazards. Further, they emphasized the necessity and importance of the contemplated investigation. The scope and general plan of these practical inquiries into the safety of cushioned blasting were indicated.This investigation of cushioned blasting relates to the various means employed to reduce the intensity of application of energy from explosive actions in boreholes. It has been suggested (from p. 19 of reference that the divisions of this work would correspond to the salient hazards affected by cushioned blasting. These include the ignition hazard, hazards from poisonous gases, and other practical hazards in the blasting technique. The ignition hazard was resolved into two components of approximately equal weight. These include studies of effects upon (1) the incendivity of blown-out shots and upon (2) the occurrence of such shots. Experimental studies of effects on the incendivity of blown-out shots were first undertaken. Questions of the best procedure for making these evaluations have been adduced, and the interpre-tation and utilization of the results of gallery testing seemed to require detailed attention; some preliminary general considerations of such testing were therefore necessary."

Jan 1, 1943

By Paul T. Allsman

This paper gives the cost and describes the mining of 55 tons of nickel-bearing rock by hand methods from a prospect in southern Nevada, June 15, 1937, by the Mining Division of the Bureau of Mines. The geology, mineralogy, and problems related to future development also are discussed briefly. The main object was to obtain a 55-ton sample within the limited period during which funds were available; little time was available to make a first-hand detailed study of the possibility of commercial ore deposits being found. The sample was desired by the Metallurgical Division of the Bureau for experimental purposes at the Electro-Metallurgical Station at Boulder City, Nev. The term "ore" is used loosely in the following discussion to designate dike material containing nickel and copper, without consideration of its commercial value. ACKNOLEDGMENTS Material concerning the geology and mineralogy of the prospect and district as obtained from Geological Survey publications by Bancroft3/and Longwell4/.

Jan 1, 1938

By P. G. Clites

The Bureau of Mines developed techniques for induction melting of titanium in a split, water-cooled copper crucible. Calcium fluoride, which was used as an inert slag cover during melting, formed an insulating layer of solid slag between the ingot and the crucible wall. This thin layer of slag effectively insulated the ingot from the crucible and prevented the molten metal from shorting across the slits between adjacent segments of the crucible. The technique provides a means of melting loose titanium sponge and scrap and eliminates the need for fabricating a consumable electrode. This report describes the equipment developed and compares ingots produced from two varieties of titanium sponge, from titanium scrap, and from previously melted titanium with ingots prepared by vacuum-arc melting and electroslag melting. A melting scheme was also proposed and evaluated whereby loose titanium sponge was consolidated into a first-melt ingot for vacuum-arc remelting.

Jan 1, 1969

By D. S. Colby

Statistics on the volume of natural gas produced in the United States were first collected for 1906. A summary of those statistics covering 1906-35 was incorporated in the 1937 Minerals Yearbook. This summary, covering 1936-50 presents, by States, a number of the more important statistics that have appeared in the natural-gas chapter of the Minerals Yearbooks. The period covered has been one of rapid expansion, especially of long-distance transmission lines. Natural gas was made available to some States for the first time; in other States the degree of dependence upon supplies transported from outside their boundaries changed rapidly. Thus, an isolated series of statistics cannot be studied without considering other regional influences that reflect in the overall operations of the industry. These tables accordingly have been designed to show for each State the simultaneous changes taking place in the various sectors surveyed. The tables show production data in the upper portion and consumption data in the lower portion. They are arranged alphabetically, by States. A copy of the 1906-35 production summary from the 1937 Minerals Yearbook has been included.

Jan 1, 1952

By William F. Jahn

Because of the' situation in Europe during the summer of 1939, with the possibility of war and consequent curtailment or loss of supplies of tin to the United States, the Bureau of Mines undertook an investigation of domestic tin resources. This was permitted by the Strategic Minerals Act of 1939, which authorized investigation of possible domestic resources of strategic minerals necessary in a national emergency. The minerals selected were in short supply, and the United States depended almost entirely on imports to meet normal requirements. The Black Hills of South Dakota were selected for investigation as one possible source of tin because of the occurrence of the mineral there has been known since 1876, although production had never been important. The Tinton area, in the northern part of the Hills, had received the most attention and contained some minor indicated and inferred tin deposits.

Jan 1, 1949

By Raghoottma S. Pandurangi, Mohindar S. Seehra, Pedro Bolsait, Bronwyn L. Razzaboni

"Surface IR (infrared) modes of crystalline and fumed (amorphous) silica particles, calcined at temperatures up to 1095°C, have been studied by Fourier transform infrared spectroscopy. The ability of these same particles to lyse cells has been measured by a hemolysis protocol. The untreated crystalline and amorphous materials differ by a factor of 40 in specific surface area, and the intensity per unit mass of the sharp surface silanol band near 3745 cm-1 in the amorphous material is an order of magnitude larger than in the crystalline material. A similar difference is observed in the lysing potential of the two materials. The intensity of the silanol band increases after calcination for both materials, reaching peak values near 500°C, followed by a dramatic drop at higher calcination temperatures, and reaching negligible values for materials calcined near 1100°C. The lysing potential data follow essentially the same pattern for both crystalline and fumed silica. These results are consistent with the hypothesis that the surface silanol groups are involved in cell lysis. Further experiments are suggested to evaluate the relationship between the surface structure of ailica particles and their potential cytotoxicity. IntroductionThe characterization of the surface structure of various allotropic forms of silica is of interest because the cytotoxicity of silica particles of respirable size has been commonly related to the chemical interaction of functional groups on the surface of such particles with the lipoproteins contained in cell membranes (1-3). It has been found that the cytotoxic potential of silica particles varies greatly with their crystalline structure (4,5), particle size (6-8), surface composition (9), and molecular surface configuration (1,10). Studies of the infrared (IR) modes of various forms of silica have been reported by a number of researchers (3 ,11-19). Several books and reviews (20-24) have dealt with the identification of functional groups on silica surfaces and the effect of heat treatment on the surface structure. The nature of the surface is said to be critical in determining the biological activity of silica dusts (3).Fourier transform infrared (FTIR) spectroscopy is a highly sensitive ·technique for identifying IR surface modes of tine particulates, and it was deemed of interest to examine the surface structure and its relation to lysing potential of two widely different types of respirable silica dust. The lysing potential of respirable dust particles has been considered a first-level test for potential cytotoxicity."

Jan 1, 1990

By J. L. Wiley

[NOTE. - P before the number indicates that the ab tract appears in patent section. Abstract numbers without. P appear in literature section. A Abietic acid, hydrogenolysis - 404 Acetone, recovery - P-4024 Acetylacetonate catalyst - P-3352, P-3664, P-6067 Acetylene, production - P-2556, P-3169, P-4064, P-4221, P-4222, P-5002 Acid catalyst - P-4584 Salts - P-4555 See also Specific acid. Acid treatment. See Procedure. Adsorption. See Hydrogen, adsorption. Agitation. See Equipment, agitators; Procedure. Alcohols: Decomposition -1128 Hydrogenation - P-3288, P-4743 In motor fuel - 1486]

Jan 1, 1952

By Brian G. White

The Coeur d'Alene Mining District of northern Idaho is remarkable for its number of large ore bodies and for the amount of its historical production of lead, zinc and silver (Fig. 1). Since veins were first discovered in 1884, more than 127 Mt (140 million st) of ore have been produced from narrow, high-grade veins. Mining continues at the Lucky Friday, Galena and Sunshine mines (Fig. 2). All have been in production for decades. At these mines, more efficient mining and exploration techniques have reduced costs while adding significant new reserves. Even the old Bunker Hill Mine, where ore was first found in 1875, continues operation on a limited basis, partly involving production of world-class pyromorphite specimens. Until recently, the Coeur Mine was also a profitable silver producer. Other large producers have included the Star-Morning, Hecla, Page, Standard-Mammoth, Hercules and Gold Hunter mines (Fig. 2). The first deposits were discovered by prospectors who spilled over from the Murray gold mining district, 24 km (15 miles) to the north. The Bunker Hill Mine was founded the year after the first veins were discovered. Bunker Hill has now operated for more than 100 years. Production includes 2.3 Mt (2.6 million st) of lead, 1.1 Mt (1.2 million st) of zinc and 4.1 kt (132 million oz) of silver. Total district production through 1996 (Springer, 1997) amounted to 7.3 Mt (8.1 million st) of lead, 3 Mt (3.3 million st) of zinc, and 34.5 kt (1.109 billion oz) of silver. This record establishes the district as the largest recorded producer of silver in the world, while also yielding major quantities of lead and zinc. Only Potosi, Bolivia, may have produced more silver, although records are unclear. Despite the district's longevity, historic production and current activity, the published literature on the district lags behind with regard to recent concepts of district geology. The most recent comprehensive US Geological Survey (USGS) bulletins (Hobbs et al., 1965; Fryklund, 1964) are dated. Much research in the last half century has been short-lived or geographically restricted because the district is large and its geology is complex - and even this research tends to remain unpublished. Thus, it has been difficult for in- [ ]

By R. C. Corey

Anticipating the need for convenient, economical, and safe means for disposing of combustible wastes contaminated with low-level activity, in connection with private and institutional uses of radioisotopes, the Atomic Energy Commission (AEC) has provided the Bureau of Mines with funds to develop an incinerator for this purpose. A prototype incinerator, designated hereafter as BOMAEC-30, was designed, constructed, and tested, based on fundamental and applied research investigations of the combustion characteristics of rubbish and sawdust, which will comprise the bulk of contaminated wastes. No radioisotopes were used in the tests; the objective was to remove as much particulate matter from the products of combustion as possible. The prototype unit was designed to burn 30 pounds per hour, using 100 percent over fire air admitted tangentially in an all-metal, cylindrical combustion chamber. The gas-cleaning system consisted of special fabric bags and absolute filters.

Jan 1, 1962

By T. H. Miller

This piper is a continuation of a series of yearly review articles started in 1925 by Thomas Varley. The development of flotation has been rapid, and better understanding of the functions o' flotation reagents has resulted in many changes in the kinds and quantities o reagents used. It is the purpose of this report to present the information in such a manner as to be of value to the milling industry as well as to the manufacturer of flotation reagents. These data have been compiled from a. survey of approximately 250 flotation plants of all classes within the United States. Many of these plants made complete reports of their operations, out others were apparently unable to supply this information in sufficient detail to meet the requirements of this investigation. Although it is realized that the data obtained in this survey are not as full as they should be to render the greatest service possible to the milling industry, it is hoped that succeeding articles will include complete information regarding milling; conditions and recoveries. As in the past, every effort has been made to conceal individual plant operations. RESULTS OF INVESTIGATION Table 1 gives the tons of ore treated by gravity and flotation methods and the concentrates produced as reported by 208 plants. The totals of 77,043,535 tons of ore and 4, 596,640 tons of concentrates from this table compare with totals of 78,973,012 tons and 4,683,972 tons respectively (furnished by the Bureau of Mines, Division of Mineral Statistics), indicating that the milling survey is about 98 per cant complete.

Jan 1, 1930

By A. H. Roberson, F. S. Wartman

For many years , it has been the common practice at most copper mines to recover copper in solution in effluent mine water by precipitating the copper with scrap iron.4/ The technique employed varies from simply throwing scrap iron or tin cans into the waste ditches to passing the water through elaborate launder systems containing detinned scrap and baled cans . In general , a considerable amount of low - cost copper has been recovered that otherwise would have been lost . Iron consumption usually varies from 1 to 1-1/2 pounds of iron for each pound of copper recovered . The grade of the precipitate may be as much as 90 percent copper.4/ ,5/ Where the consumption of iron is materially greater , its cost is likely to be the determining factor of profit . In times of emergency, when the demand for scrap iron for remelting increases the cost of the iron sharply, and the supply of tin cans is not large enough to meet requirements , recovery of the copper might not be economical . The three principal reactions that take place when an acid mine water containing iron and copper salts in solution is brought into contact with metallic iron are : (1 ) Copper is precipitated and an equivalent amount of iron is dissolved , CuSO4 + Fe Cu + FeSO4 ; ( 2) ferric salts are reduced to ferrous salts , Fe2 (SO4 ) 3 + Fe = 3FeSO4 ; and (3) the free acid in the solution reacts. with metallic iron to produce ferrous sulfate , H2SO4 + Fe = H2 + FeSO4 . = Because of the reported high.consumption of iron (5 to 6 pounds per pound of copper precipitated ), when copper in water from the Hornet mine of the Mountain Copper Co. ( California ) was precipitated upon scrap iron , a series of tests was made to determine . the . optimum treatment, time , and consumption of iron .

Feb 1, 1944

By C. P. Bowie, George L. Gates

"INTRODUCTION Experience in drilling oil and gas wells has shown that the voidance of blow-outs, twist-offs, fishing jobs, loss of circulation, and heaving and caving of shale formations into the drill hole depends largely on how well the drilling-mud fluid serves its purpose. A possible method for the control of the drilling fluids may be seen from a study of the relation between the particle-size distribution and some of the important drilling-fluid properties, such as the ability to build quickly a relatively impervious mud sheath on the wall of the hole in the porous formations penetrated by the bit during drilling operations. In a wartime economy, which urgently requires conservation of steel, proper functioning of the drilling fluid is particularly important because, as Parks 4/ has stated, intelligent use of good drilling fluids makes possible drilling of wells for thousands of feet in open holes without the necessity of setting protective strings of casing to control the movement of salt water, gas, and troublesome formations into the borehole; consequently, especially in deep wells, of proper drilling fluids materially reduces the need for casing and lowers the cost of drilling and completing the wells."

May 1, 1942

By L. H. Johnson

"INTRODUCTION The Pennsylvania anthracite industry produced 53 million net tons of anthracite during 1945. Fifty-one million tons was prepared for the commercial market (3), 3/ and 2 million tons (consisting of fine sizes) was used for colliery power consumption. Of the number of tons prepared for market, 17 million tons (33 1/3 percent) was prepared by the use of acid mine water treated with lime.Mine water from underground workings is pumped, drained, and stored in huge quantities. The mine-drainage systems in the anthracite region handle over 200 billion gallons of water annually, of which 150 billion gallons is pumped to the surface. More than 69 billion gallons of water is impounded in underground pools (1). Much of this water is employed for breaker use, dust-control installations; hydraulic backfilling, combatting mine fires; and aiding in the transportation of anthracite in gently dipping places where sheet iron is used Roos(4) estimates that 1,100 gallons of mine water is utilized in the preparation of anthracite mined."

Nov 1, 1946

By B. W. Jong

The Bureau of Mines studied reinforcement of sulfur concretes using glass, polyester, and aramid fibers. The objective of this research was to determine the feasibility of fiber-reinforcing the sulfur concrete to enhance the flexural properties. Optimum fiber sulfur concrete compositions were formulated with a cement-to-fiber ratio of 9.0:1 for glass-fiber and polyester-fiber sulfur concretes and 12.1:1 for aramid-fiber sulfur concretes. Test samples were prepared using techniques developed by the Bureau of Mines. Flexural strength values of up to 50 pct of compressive strength values were achieved with fiber additions. With non-fiber-reinforced sulfur concrete, the values ranged up to 20 pct. The impact strength and fracture toughness of sulfur concretes were increased sig-nificantly by reinforcement with glass or with aramid fiber and were adversely affected by use of polyester fiber. Strain tolerance was doubled and failure mode was shifted from catastrophic to noncatastrophic type by adding glass fiber. The glass-fiber and aramid-fiber sulfur concretes are resistant to acid corrosion and have proved durable in freeze-thaw cycles. This laboratory and field evaluation has shown that fiber reinforcement of sulfur concrete is feasible and that it enhances the flexural properties.

Jan 1, 1985

By David M. Gullikson

Since publication of the paper on the composition of California oilfield waters by Jensen (6)3/ in 1934 the only other information on the subject was published recently by Chave (4). To supply needed information on the composition of California waters in areas of current drilling activity, the Federal Bureau of Mines collected formation water samples for analysis. Thirty-eight samples from oil-and gas-producing formations in 12 fields located in Ventura, Kern, Glenn, and Colusa counties were analysed by the Bureau's San Francisco Petroleum Research Laboratory. The samples were selected particularly from fields where the water composition was not well known or where interpretation of electrical logs has been difficult and the interpretation may be affected by unusual composition of the water. These samples were obtained from rocks ranging in geologic age from Cretaceous to Upper Pliocene. Fifteen constituents of these waters were determined including sodium, potassium, calcium, magnesium, strontium, barium, lithium, chloride, iodide, bromide, carbonate, bicarbonate, sulfate, borate, and residual acidity. These analyses are the first to be published on California oilfield waters in which determinations for potassium, strontium, bromide, iodide, boron) and naphthenates were made on a significant number of samples. The electrical resistivities of tae samples were determined at 75° F. and 175° F.

Jan 1, 1961

By D. R. Mathews

Electrorefined vanadium was evaluated with respect to tensile properties and the effects of interstitial contaminants in the temperature range of 77° to 273° K. The yield strength of 18,500 psi and hardness of 63 diamond pyra-mid hardness (DPH) of electrorefined vanadium are approximately equal to that of iodide crystal bar vanadium. The ductile-brittle transition temperature was found to be below 77° K, but with 0.175 weight-percent oxygen or 0.10 weight-percent nitrogen, it increased to between 123° and 190° K. With carbon content up to 0.11 weight-percent, the transition temperature remained below 77° K. The yield strength of the interstitial-containing alloys can be expressed by: au = 7.5 + 480 (pct N) + 290 (pct 0) + 280 (pct C), where au is the upper yield stress in 1,000 psi at 273° K. Profuse deformation twinning occurred in the alloys tested at 77° K. However, twinning could be suppressed by dissolved oxygen or nitrogen in excess of 0.15 and 0.086 weight-percent, respectively. Carbon, even though present in excess of the solubility limit, did not affect twinning.

Jan 1, 1965

By John H. Soulé

"INTRODUCTION The Mining Branch of the Bureau of Mines has used the wagon drill to sample mineral deposits in New Mexico. This method of sampling was successful and con¬stituted an important phase of the work on five exploratory projects undertaken in 1943, 1944, and 1945. The deposits varied in topographic features, geology, mineral content, and in the physical characteristics of the rocks drilled. The altitudes ranged from 630 to 7,800 feet. Three hundred and seventeen holes totaling 6,852 feet were drilled. The deepest hole was 66 feet; the average depth was a little less than 22 feet.The results of the above-mentioned work form the basis of this report. Special attention is given to the later and more improved techniques used. This report was written with the expectation that the procedures might prove advantageous to others in the exploration and sampling of near-surface mineral de¬posits, and that a more extended use of the technique might result.AcknowledgmentsAcknowledgment is due Charles H. Johnson, chief of the Rolla Division, Mining Branch, for helpful suggestions in starting this work, and to J. H. Hedges, chief of the Tucson Division, Mining Branch, W. R. Storms, engineer-in-charge of the Silver City, N. Mex., Field Office, and Donald H. Mullen, mining engineer attached to that office, for assistance in preparing and editing this report."

May 1, 1947

By E. C. Perkins, R. S. Lang, D. M. Taylor, H. Dolezal

The amenability of titaniferous slags and domestic mineral concentrates to chlorination was determined in a 6 - inch diameter fluidized bed chlorinator . Ilmenites from Valley County , Idaho ; Aiken , S.C ,; Trail Ridge , Fla .; and MacIntyre , N.Y .; and a titaniferous magnetite from Iron Mountain , Wyo . , were used in preparing the slags . The domestic minerals tested were an ilmenite concentrate from Valley County , Idaho , and a rutile concentrate from Magnet Cove , Ark . A high - grade Australian rutile was used as a standard for comparison . The impurity content of the slags and minerals tested , which was the most critical factor affecting their performance , was dependent on the geographical source of the material . All of the materials tested were amenable to chlorination in a fluidized bed although some required special operating conditions . Titanium extractions and chlorine utilization were over 90 percent for most of the slags and the Australian rutile . The Valley County , Idaho , ilmenite performed well in the reactor despite its 34 percent iron content .

Jan 1, 1963

By Kenneth E. Hay

The Bureau of Mines collected coal and coal waste aggregate material from two different mine sites to determine their strength characteristics for use in concrete. The concrete would be placed underground as support walls for ground control in adverse conditions or unique mining applications. A standard mix design was established for a "wet" mix using a water-to-cement (w/c) ratio of 1.0 to facilitate pumping into place. Later, material was collected from four more mine sites and used to make 2-by 2-by 2-ft test blocks with the same w/c ratio. A pull-out cone device and borehole shear tester were used to determine the in situ material strength of the test blocks. These techniques will provide a simple and quick way of determining support wall strength in an underground environment. Test results from the pullout cone de-vice showed a good correlation of 0.98 to test cylinder compressive strengths of the same mix. Results of the borehole shear tester were inconclusive.

Jan 1, 1986