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By William J. Campbell

The columbite-tantalite mineral series was studied by various instrumental techniques to establish the relationship of density to composition. The samples used were carefully selected to obtain a mineralogical purity of at least 98 percent. Impurities were determined by optical microscopy, X-ray diffraction, and optical and X-ray spectroscopy. Each sample was analyzed by fluorescent X-ray spectroscopy for iron, manganese, columbium (niobium), and tantalum. The existence of a unique relationship in this isomorphous series permits a simple correlation of the intensity of a spectral line with the concentration of the analytical element.

Jan 1, 1955

By LeRoy R. Curwick

This Bureau of Mines report presents the results of a study conducted to assess the domestic availability of chromium from superalloy and cast heat- and corrosion-resistant alloy scrap material. Six alloy classes included in this survey were investment cast, hardfacing, and wrought nickel- and cobalt-base alloys, wrought nickel-iron-base alloys, and heat- and corrosion-resistant alloy castings. Data were collected for 1976 on metallic scrap generation, use patterns, and production practices for these alloy producing and using industries. A model was developed that allowed an assessment of the materials flow circuits within the industries that produce these alloys. The types, amounts, sources, secondary products, and ultimate destinations of chromium- containing metallic scrap for the six alloy classes were determined. Regarding the overall recycling efficiency of these alloy producing and using industries, of the 580.9 million pounds of scrap generated from these six alloy classes in 1976, about 72 percent (416.8 million pounds) was remelted by the same alloy-producing industries, about 18 percent (104.9 million pounds) was downgraded into stainless and low-alloy steels, about 3 percent (19.7 million pounds) was exported, and about 7 percent (39.5 million pounds) was lost through landfill or other disposal or service wastage. The lost material is primarily contaminated oxides for which recovery is currently uneconomic. However, the 124.6 million pounds of scrap material downgraded or exported in 197b contained potentially recoverable critical strategic elements. The amount of scrap material lost to the six alloy-producing industries in this manner contained 22.1 million pounds of chromium, 53.4 million pounds of nickel, 5.9 million pounds of cobalt, 35.9 million pounds of iron, and 7.3 million pounds of other alloying elements.

Jan 1, 1980

By G. L. Oldright

In the previous study that has been made by the authors on smelting in the lead blast furnace,4 the furnace examined was one that operated under conditions that have been considered as more or less normal up to the present time. That is, although the furnace had in its charge a large portion of sinter, it also handled considerable quantities of naturally oxidized direct-smelting ore. Other ingredients, such as the limestone, were also added as fairly coarse material. The charges contained only about 24 per cent of lead. Until the changes incident to modern flotation began to take effect, many lead plants doing semicustom smelting in districts where competition was keen and much of the bonanza ore was exhausted were faced with the difficulty of obtaining enough lead to get a sufficient "lead fall" in the blast furnaces to clean the slag thoroughly and to separate it from the lead. A charge containing 24 per cent of lead would have been considered a very rich one by such smelters.

Jan 1, 1931

By G. L. Oldright

In the previous study that has been made by the authors on smelting in the lead blast furnace, the furnace examined was one that operated under conditions that have been considered as more or less normal up to the present time. That is although the furnace had in its charge a large portion of sinter, it also handled considerable quantities of naturally oxidized direct-smelting ore. Other ingredients, such as the limestone, were also added as fairly coarse material. The charges contained only about 24 per cent of lead. Until the changes incident to modern flotation began to take effect, many lead plants doing semicustom smelting in districts where competition was keen and much of the bonanza ore was exhausted were faced with the difficulty of obtaining enough lead to get a sufficient "lead fall" in the blast furnaces to clean the slag thoroughly and to separate it from the lead. A charge containing 24 per cent of lead would have been considered a very rich one by such smelters.

Jan 1, 1931

By M. M. Wong, J. E. Klosterman

Scrap beryllium chips ( nominally 96 to 97 percent Be ) were electrore fined in a prototype cell with 408 lb of electrolyte composed of 52.4 mole - percent LiCl , 36.3 mole - percent KC1 , and 11.3 mole - percent BeCl2 . The cell temperature was 500 ° C. In a typical 10-3 /4 - hour deposition cycle , 0.415 pound of metal was produced ; the metal contained impurities in parts per million as follows : C , 700 ; 0 , 610 ; Al , 34 ; Ca , 32 ; Cu , 20 ; Fe , 25 ; Mg , 9 ; and Mn , 23 . Operation of the prototype cell for 2 years demonstrated that adapting the electrorefining process to an enlarged scale of operation presented few difficulties in mechanical functions , maintenance of optimum operating conditions , and control of product purity . After the spent anode feed was leached in a 5 - percent nitric acid solution and the fine - sized particles were removed , it was recycled in some tests . The metal produced was somewhat higher in impurities than metal from the fresh scrap chips .

Jan 1, 1964

By J. E. Schiller

The Bureau of Mines is investigating methods to treat waste water that contains cyanide. This report describes a new method that removes heavy metals and all forms of cyanide. In the first step, hydrogen peroxide and sodium thiosulfate are added at pH 7 to 9 in a 1:2 molar ratio to convert free and weakly complexed cyanide to nontoxic thiocyanate. Then steryldimethylbenzylammonium chloride is added to precipitate ferro-cyanide, and finally, ferric sulfate is added as a sweep floc and sequestrant for heavy metals. After the suspended solids settle, the water is polished by filtering. The water initially contained 1 to 5 mg/L Fe, 1 to 5 mg/L Cu, and 10 to 30 mg/L total cyanide; the level of each of these constituents was reduced to less than 0.02 mg/L.

Jan 1, 1983

By F. P. Haver

Because State and Federal agencies have limited the amount of sulfur oxides that can be discharged to the atmosphere, most copper smelters plan to convert the S02 in offgases to sulfuric acid. In some cases, however, it might be preferable to use a nonsmelting method to fix the sulfur in the form of a discardable product. Research by the Federal Bureau of Mines has shown that sulfur in copper concentrate can be converted into insoluble anhydrite (CaS04) by roasting the concentrate with lime (CaO). After leaching the calcine to recover metal values, the residue may be discarded without harm to the environment. The process can use a rougher flotation product, thus reducing separation costs and saving valuable minerals (for example, molybdenite) that are now lost in making cleaner concentrate. In tests, rougher concentrate was pelletized with the theoretical amount of lime and roasted for 1 hour in a 6-1/2-inch-ID by 11-foot-long rotary kiln at 700° C. Sulfur retention was about 97 percent. Leaching the calcine with 20 percent RCI extracted approximately 99 percent of the copper, 73 percent of the iron, and 91 percent of the molybdenum. After the molybdenum was removed from the leach solution by adsorption on activated carbon, copper with a purity in excess of 99 percent was obtained by cementation on sponge iron. The strip solution then could be spray-roasted at 500° C to recover the RCI for recycle and obtain F2O3 as a byproduct.

Jan 1, 1975

By Brinton C. Brown

This paper describes the methods and equipment developed at the Bureau's Experimental Oil-Shale mine near Rifle, Colo., for placing men in position to scale loose rock from the walls, pillars, and roofs of high stopes or rooms. The equipment developed at Rifle has application not only in oil-shale mining but in most of the country's underground limestone mines and in the exploitation of other mineral deposits mined in high stopes by room-and-pillar methods. Equipment in use at Rifle includes: 1. A boom-type scaling rig with a self-leveling platform constructed on a small "cat"-mounted crane. Men working from the platform on this machine can efficiently scale mine walls and roofs 27 feet above the floor. 2. A conventional fork-lift truck modified to provide a remotely controlled working platform from which men can scale to heights 27 feet above the mine floor. The platform on this unit is larger than on the boom-type rig and allows the men to inspect larger areas of the mine wall from a single setting of the machine. 3. A third rig, consisting essentially of a platform mounted on a tele-scoping tower, designed and built to elevate men 65 feet above the mine floor. Versatility of this machine permits men to work from the platform at heights of 5 to 65 feet. In the operating position, the unit requires a minimum clearance of 25 feet. In the nonoperating position the tower of the machine folds to an over-all height of 15 feet 10 inches to permit travel through haulageways. 4. An industrial gun, lightweight scaling bars, and mechanical scalers, which have been tried for removing loose rock from the mine walls with varying degrees of success.

Jan 1, 1950

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 D. W. Bridges, L. Crocker, R. O. Dannenberg

About 95 pct of the beryllium was dissolved from most ore samples by agitation leaching with 600 lb of H2SO4 per ton of ore for 24 hours at 65 ° C and 35 pct solids . Leach slurries generally were viscous , and the limiting pulp density for thorough mixing was about 35 pct solids . Settling of the leached pulp required 0.6 to 0.8 lb of a polyacrylic flocculant per ton of ore leached with 600 lb of H2SO4 per ton , whereas ore leached with 800 lb of H2SO4 per ton required only 0.2 to 0.3 lb of flocculant per ton . Terminal densities of the settled pulps were about 28 and 35 pct solids , respectively , from leaches using 600 and 800 lb of H2SO4 per ton . Vacuum filtration of settled pulps at 15 in . Hg resulted in a filter cake containing 50 to 59 pct solids . Roasting the ore at 500 ° C before leaching increased the limiting pulp density for effective mixing to 50 pct solids . Acid requirements , however , were not diminished , although leaching roasted ore with 600 lb of H2SO4 per ton resulted in densification of settled pulps to about 40 pct solids . Filter cake from leaching preroasted ore contained about 20 pct less water than that from unroasted ore .

Jan 1, 1963

By A. Wahab Khair

"This paper presents an analysis of fracture mechanisms in coal subjected to bi-axial state of stresses, indentation of laterally confined coal specimen. Coal specimens were loaded to failure by the straight wedge indenters at various lateral confinement pressures. Strain distribution and acoustic emission characteristics of coal specimens under stress were recorded. The influence lines of vertical forces acting on the horizontal straight boundary of the coal specimen for each type of wedge indenter have been established using holographic interferometry technique. The effects of wedge indenter angle, confinement pressure, and coal anisotropy on fracture types, failure modes, and post-failure conditions were studied. The results indicated that combined application of holographic interferometry and acoustic emission monitoring techniques is not only suitable ·for studying deformability of heterogeneous and microscopically discontinuous material under stress but it also enhances the mode of fracture during the post failure stage. INTRODUCTIONOne of the relevant processes in the coal cutting technology is the application of indentation theories. Since most cutting tools in the coal industry are wedge shaped most of the indentation research is found for a wedge shaped tool.A wide range of behavior is found in different rocks subjected to the wedge penetration. A rock which is elastic brittle at standard pressure might become elastic plastic at high confining pressure (Gnirk and Cheatham, 1963). It was also observed that some rocks will merely be crushed and indented by a wedge whereas others will crack and form chips, furthermore the existence or non-existence of chips depends mostly on the geometry of the indenter, type of rock and the depth of penetration (Evans and Murrel, 1958). However, coal cutting technology is mostly explained by models which use rigid wedge to penetrate into a brittle material in which both crushing and chipping will occur (Evans and Murrel, 1958, 1962)."

Jan 1, 1988

By J. L. Eakin

A method was developed by the Bureau of Mines in the laboratory and in the field to relieve capillary waterblocks in gas wells. Impaired gas permeability was improved by this inexpensive chemical treatment which lowers the surface tension of the water held in the capillaries of the formation. Effectiveness of the alcohol-surfactant treatment was tested with a variety of chemicals and with sandstone cores cut from rocks having relatively low permeability. Field tests on 20 gas-producing and storage wells demonstrated the effectiveness and limitations of the method. The productive capacity of some wells was doubled by the treatment. The final test was evaluated by the neutron logging technique for measuring changes in apparent liquid saturation. Maximum apparent liquid saturation was reduced by 52 percent; gas production rate increased from 2.3 to 3.5 MMcfd (million cubic feet per day).

Jan 1, 1965

By William S. Roberts

The Bureau of Mines has initiated a program to determine the availability of land for mineral exploration and development in Alaska. Researchers involved in this pro-gram are comparing land availability, based on ownership and government policies and regulations, to the distribution of known mineral deposits and terranes. This report on southeastern Alaska presents the findings of the first of six regional studies that will cover the State. The study consisted largely of data compilation and analysis using various mapping techniques. Summary land availability data are presented on copies of U.S. Geological Survey (USGS) quadrangles at a scale of 1:500,000. Five categories of land availability were identified: open to mineral exploration and development (approximately 9.4 million acres, or 38% of the 24.8-million-acre study area), open but with possible use restrictions (4.2 million acres, or 17%), selected (0.5 million acres, or 2%), patented (0.74 million acres, or 3%), and formally closed to mineral exploration and development (10 million acres, or 40%). Of the 1,187 known mineral deposits in the study area, approximately 38% are on land in the open category. Mineral terranes comprise approximately 6.7 million acres, or 27% of southeastern Alaska. Approximately 34% of these terranes are on open land.

Jan 1, 1985

By N. H. Darton

In mining coal in the anthracite region of Pennsylvania the general custom has been to leave a large percentage of the coal in place as pillars to support the roof. Evidently any practice that involves partial waste of an important mineral resource is bound to be discarded. It is well recognized that one method of obviating probable waste is to fill the workings with cheap or worthless materials, a process extensively employed in the anthracite and some European mines. At present many of the collieries in the anthracite region of Pennsylvania are utilizing refuse from the old culm banks, which formerly were prominent features in the landscape, and are flushing the fine waste underground so that pillars may be reduced in size or removed. As a result the banks are now disappearing and soon will be gone. The fine culm from the breakers and rock from the mines will continue to be available, but the volume of these materials is insufficient to replace any considerable proportion of the coal removed. The next stage of progress suggested is the use of sand. Fortunately there are available large deposits of this material, much of which can be handled by dredges and pumps. This report is issued by the Bureau of Mines in the interest of safer and more efficient mining methods. I ts purpose is to describe the sand deposits in the northern anthracite coal field in Luzerne and Lackawanna Counties, Pa, Much of the information available is presented in the map, Plate I. Field studies, mostly preliminary, were made in the summer of 1911 to determine the distribution, amount, and character of the larger deposits. It was not thought desirable to make a detailed examination of the region because when the coal companies decide to utilize the sand their engineers will make precise surveys and drill test holes. In preparing the map the various coal companies were consulted; they contributed a large number of facts, especially as to the deposits in the buried valley of the Susquehanna between Pittston and Nan- ticoke, where nearly 1,000 test holes have been bored. The results of these borings were placed at the author's disposal, and have been utilized in drawing the boundaries given in the wide valley area and its extensions up Lackawanna River and NewportCreek. Wyoming Valley contains deposits of sand that are 100 feet thick over a wide area, 200 feet thick in places, and over 300 feet thick in the deep old channel south of Plymouth.

Jan 1, 1913

By Matthew N. Rubin

This report summarizes the work performed under USBM Contract No. H0155155, "Demonstrating the Noise Control of a Coal Preparation Plant." A Consolidation Coal Company coal preparation plant (the Georgetown Plant) was selected for demonstration of various noise control techniques and materials in a commercially operating plant. At the start of the project, the 1650 tons per hour (tph) plant was surveyed to document the existing sound levels and worker noise exposures. On the basis of the survey, individual noise sources were characterized and assigned priorities for treatment. Four categories of noise control treatments were installed in this plant: ? Resilient impact pads ? Curtains ? Chute liners ? Resilient screen decks. Currently (1977) available resilient impact pads and curtains were found to be suit-able for general use in coal preparation plants; in the Georgetown Plant, they provided significant noise reduction [6 to 10 dB(A)]. The overall performance of the chute liners which also provided useful noise reduction, was strongly dependent on the specific installation. Although the resilient screen decks have the potential for 7 to 9 dB(A) of coal/screen impact noise reduction, blinding and delamination (in composite decks) en-countered at the Georgetown Plant represented major design problems for these products. This program achieved noise reductions of up to 10 dB in various areas of the Georgetown Plant (within the restrictions imposed by the plant's operation) resulting in significant reduction in worker noise exposures.

Jan 1, 1977

By K. K. Kelley

Despite the wide interest in titanium and its compounds, no heat and free-energy-of-formation values for titanates (that is, compounds formed from titania and other metal oxides) have been available heretofore except for ilmenite (FeTi03). Such data are needed for understanding and developing processes for producing titania and titanium tetrachloride from ores (and possibly slags) and in connection with ceramic usage of titania. This paper reports experimental measurements of the heats of formation at ordinary temperature of 11 titanates-ilmenite, perovskite, barium metatinate, strontium metatitanate, barium-strontium metatitanate, barium orthotitanate, strontium orthotitanate, barium-strontium othotitanate, geikielite, magnesium-titanium spinel, and magnesium dititanate. The experimental method was solution calorimetry. The solution calorimeter was operated at 73.7°C. and used a strong hydrofluoric-hydrochloric acid mixture as the calorimetric fluid and reaction medium.

Jan 1, 1954

By Loren R. Anderson

This Volume documents the use of the Cone Penetrometer data analysis computer programs VERT and HORZ. The programs are interactive in that they prompt the user for input data and allow correction and modification to be made. The programs read data from the results of cone penetrometer soundings and convert the data to values of tan ø. Mean, standard deviation, skew, kurtosis, linear trends and autocorralation are computed by the programs.

Jan 1, 1982

By W. A. Grosh

The Piquette Mining and Milling Co, operates a zinc mine and concentrating mill in the Upper Mississippi Valley zinc-lead district near Tennyson, Wis. The principal ore mineral is zinc sulfide, which occurs in limestones and dolomites of the Decorah formation. Exploration in the district is by churn drilling from the surface. An adit at the base of the ore zone provides access to the mine. A room-and- pillar mining method with irregular pillars is used. Drilling is done with Jumbo-mounted drills. The broken ore is loaded by crawler-mounted front-end loaders into diesel-powered trucks for haulage direct to the mill.

Jan 1, 1959

By G. Richards Gwinn

Vermiculites are secondary minerals formed by the: alteration of biotite and philogopite mica and are associated with basic rocks such as dunites, serpentines, and pyroxenites. Vermiculite was first described by T. H. Webb in 1824. It remained a mineralogical curiosity until 1913, when the first commercial deposit was discovered in the Turrett mining district of Colorado. Expanded or exfoliated vermiculite was first marketed in 1915 from a deposit in this district 5 miles southeast of Hecla, Colo. This activity was brief, but successful and continuous commercial development began in 1921 in Montana. 'Deposits in other States have been found and developed, but Montana is by far the largest producer. Vermiculite has also been found in South Africa, Western

Jan 1, 1944

By S. J. Broderick

"INTRODUCTION Dark soils are commonly believed to be better for agricultural purposes than light-color soils. Much of this feeling may be purely psychological, as many persons have unconsciously acquired the habit of associating richness of soil with color light soils, however, may be just as rich in humus and plant foods as the best of the dark soils. A dis-cussion of the manifold attributes that play an important role in soil technology is beyond the scope of this paper, but the color factor will be considered, as it has a particular bearing on some field experiments using coal-mine waste as a darkening medium.It has been established that dark soils absorb more of the sun's radiation, consequently are maintained at a higher temperature than light soils. This physical principle is applied in our daily lives in the choice of clothing. White clotnes in summer are cooler than dark ones. Conversely, dark clothes in winter are warmer than light-color clothing. A decided advantage of dark soils over light soils is the higher average temperature of the former, resulting in an earlier maturing crop. This advance of the maturing season may range from a few days to a month, depending on such factors as climate, crop, and degree of color of the soil. It has been reported that in parts of Russia where the growing season is short, perhaps comparable to that in Pennsylvania and. New York, cotton has been grown successfully on soils originally of light color, but darkened with coal, dusts. The growth of cotton is, accordingly, speeded up a full month. 3/"

May 1, 1940