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By H. Kenworthy

Small batches of fluorspar flotation concentrates were made into nodules and pellets on a laboratory scale. Several of these were rated acceptable by laboratory evaluation methods. The most satisfactory pellets were produced by mixing fluorspar with about 12.5 percent of water, by weight, and 4 percent of organic binders. These binders) for the most part) originated from petroleum and wood-pulp industries. They were generally difficult to handle and were not easily incorporated with the fluorspars tested. Most of them seemed to have an aversion for damp fluorspar and had to be forcibly mixed with the fluorspar; which was then formed into pellets by pressure. Substitution of fuel oil in varying amounts in the binders enhanced the mixing and penetrating qualities of these binders but at the same tire tended to make the pellets more porous. Tall oils performed the same function to a lesser degree and usually decreased the water absorbency of the finished pellets. Heat-treating temperatures to set up these binders were moderate -about 5000 F. for 30 to 50 minutes was usually enough for both drying and heat treating. Nodules made with 1-1/2 to 2 percent of bentonite as a binder were easily mixed and formed. They required a high degree of heat (about 1,500° F.) to develop their strength and were quite water-absorbent when finished. Two fluorspars were examined for weight and fluorite loss after heat treatment at similar temperatures. Both showed a definite wej.ght and analytical loss of fluorite. Bentonite was used also as a binder to successfully nodulize finely ground oxides of iron, manganese, and nickel.

Jan 1, 1951

Surface mining and reclamation of a southeastern Ohio site with sandstone-shale overburden resulted in (as compared to premining levels): 1) runoff volumes and peak rates that increased by a factor of from 2 to 10 during mining and after reclamation, 2) destruction of the "aquifer" perched on the underclay of the mined coal bed and gradual, but, as yet incomplete redevelopment of this aquifer after reclamation, 3) no immediate effect on another, lower perched "aquifer", 4) up to 100 times greater sediment concentrations in runoff. Results were influenced by increasing annual precipitation amounts through the period of record; 1978, 1979, and 1980 (postreclamation years) experienced precipitation amounts approaching or exceeding long-term normalcy for the area. Part of the reason that the site produced more runoff after reclamation than before mining is that the premine condition was one of an open, porous soil under woodland, while the postreclamation condition was one of a compacted, bulldozed soil. Sediment concentration results were influenced by failure of the postreclamation erosion control system and by a series of detention reservoirs above the stream monitoring station.

Jan 1, 1983

This summary of State laws on explosives was compiled primarily to ascertain what subjects relating to their control have been acted upon by each State legislature and, in general, how they have been treated. It does not include any legislation passed after 1942, or any proclamations, regulations, or administrative orders. It does not purport or attempt to be authoritative. If any problem arises involving interpretation of the statutes of any particular State, the original source must be consulted for the exact words used by the legislature. This summary, however, will be useful in determining whether relevant statutes exist and in locating them quickly, with a minimum of effort. It will be of value also in comparing statutes in one State with similar statutes in other States to determine what construction has been placed upon them by the courts of those jurisdictions or to contrast the varying provisions of many States upon a single subject. To make these comparisons easier, the statutory provisions for each State have been grouped under several major topics in outline form. Although

Jan 1, 1943

By H. F. Yancey

One of the important duties of the Bureau of Mines is to sample and analyze coals and to publish the results of such analyses for the information of producers, consumers, and the general public. Numerous publications containing such analyses have been Issued from time to time. Although the chemical properties of a coal as revealed by its proximate and/or ultimate analysis and heating value aid one considerably in visualizing its probable behavior and in determining its usefulness and value for a specific purpose, they do not furnish complete information. The physical properties of a coal, such as its ability to retain its original form without undue breakage or degradation in size under the various conditions of storage and usage, are also of importance in determining its suitability, technically or economically, for a given purpose.

Jan 1, 1932

By Mark Sheppard

[Considerable research work hi been done on secondary crushing and coarse and fine grinding, and the literature on the general subject of Crushing contains many references to the work of investigators on the laws governing end the factors entering into the economical production of fine materials. However, little information on primary crushing in available The literature deals mainly with problems and practices in ore dressing, end in this field the engineer or investigator is concerned largely with the production of fine material and the unlocking of minerals in the ore. Under such conditions close control of screen sizes of primary-crusher products is a secondary consideration and has received very little attention.]

Jan 1, 1938

By Felix duBreuil

The present sampling procedure for evaluating the rock dusting conditions in a coal mine is time consuming. This study considers means by which this procedure could be simplified. Surveys were conducted in six coal mines in Pennsylvania to determine the in¬combustible content of the deposited dust. Some 2,000 samples were analyzed and statistically evaluated. It is suggested that the mean incombustible content could be obtained with fewer samples and smaller samples without greatly increasing the sampling error.

Jan 1, 1972

By J. A. Woolf, E. S. Leaver, N. K. Karchmer

"In the cyanidation of silver ore, the need of oxygen is well recognized. Various methods have been introduced for supplying the oxygen. In usual practice, air is the source of oxygen and the methods of application are mechanical.This article gives the results of touts made to show the rate of dissolution of silver from each of the common silver minerals in cyanide solution, under conditions similar to those used in the practical recovery of silver from its ores. The effect of oxygen in aiding the dissolution of the silver from each mineral is also shown by a comparison of the methods of supplying the oxygen. Oxidation by preliminary roasting (500°C.) of each mineral sample gives the maximum extraction of the silver by treatment with cyanide.Each silver mineral5 used in these experiments was as pure as could be obtained from the mineral dealer. In their natural occurrence, silver minerals are not usually free from mineral impurities. They are usually closely associated with other minerals often forming, a complex mixture. The form of crystallization, the proportions, and properties of the diluent that incases or has been dispersed with the silver mineral may decidedly affect the dissolution rate of the silver from each mineral. While the following results should aid in the cyanidation of silver ores, each ore should be studied from the basis of the form and condition of the silver that is to be recovered.All the tests reported in this article were made on synthetic samples, prepared by mixing the particular silver mineral with clean sea sand. Each mineral was ground in an agate mortar to pass 100-mesh before mixing with the sand which had previously been ground in a porcelain pebble mill to 100-mesh. Such proportions of each mineral and the sand were used as to give a head assay of approximately 20 ounces of silver per ton to the synthetic sample.Agitation was carried on in stoppered bottles approximately one-third full of pulp, method apparently supplied all the atmospheric oxygen that would be taken up by the solution under usual conditions, because tests conducted in open bottles did not show increased recovery,"

Jan 1, 1931

By John P. Powell

The increasing demands for petroleum and its products and the steadily increasing cost of discovering and developing new oil fields are factors that emphasize the importance of increasing the recovery of oil from known petroleum reserves. Water flooding is a valuable conservation measure, not only preventing premature abandonment of stripper leases but also reviving interest in many areas previously abandoned. The use of water flooding as a means for recovering additional oil from partly depleted oil-bearing formations was first tried in Oklahoma in 1931. Early water-flooding operations were confined to the area of shallow Bartlesville-sand formations in Nowata and Rogers Counties, where many of the projects were outstandingly successful. The results of these operations stimulated activities in other pools in Oklahoma, and by the end of 1949 water flooding had been tried in 25 of the 49 oil-producing counties in the State (fig. 1). Approximately 33 million barrels of oil, or 1,806 barrels per acre, had been recovered by December 31, 1949, from 18,221 productive acres included in the 162 active and abandoned projects in Oklahoma by injection of approximately 449 million barrels of water.

Jan 1, 1952

By Kenneth P. V. Lei

The Bureau of Mines investigated a silver-catalyzed oxidative procedure for leaching an arsenical copper sulfide concentrate containing 10 pct As and 32 pct Cu_ Currently, there are no environmentally safe means to treat arsenical copper concentrates in the United States. Leaching was conducted in a 2-L autoclave reactor. The effects of catalyst concentration, O2 pressure, temperature, and H2S04, Cu, As, and Fe concentrations in the leaching solution on extractions of metals from the concentrate were determined. The best leaching conditions for extracting 95 pet eu and As and less than 21 pct Fe were 260 g/L concentrate, 0.007 mol/L (1.0 g/L) AgCI, 3.0 mol/L (294 gIL) H2S04, 1000 C, 60 psig 02, and 6 h. Copper as CuS04-5H20 was recovered by crystallization from the pregnant solution. Arsenic, as AS203, was recovered from the copper mother liquor by solvent extraction, with tributyl phosphate, S02 reduction of As5+ to As3+ in the strip solution, and crystallization of the As3+. The silver catalyst was recovered by contacting the leached residue with a brine solution. A conceptual scheme is proposed for treating arsenical copper sulfide concentrates.

Jan 1, 1987

By A. A. Berk

The Bureau of Mines devised a test nipple for the field study of corrosion in the condensate-return lines of Federal heating plants. Corrosion surveys, made with this device, showed that the deterioration of the piping was caused principally by carbonic acid in the steam condensate. Corrosion problems were brought under control when the carbonic acid concentration in the condensate was decreased. In many instances, this was effected by decreasing the total carbon dioxide content of the feedwater; in others, the condensate acidity was neutralized with volatile, alkaline chemicals. Filming treatment with octadecylamine, reported successful in controlling return-line corrosion in industry, was much less effective in Federal area-heating plants. Laboratory study by the Bureau disclosed that octadecylamine is unstable in heating systems. Analytical methods were developed for this chemical and its degradation products in heating-plant condensate. Field surveys, in using these methods, confirmed the instability of the filming material. Laboratory tests showed that the degradation products are not useful film formers. Since filming treatment has little effect on condensate corrosivity, the piping was corroded where it was not coated by the treatment chemical.

Jan 1, 1962

By Leland E. Paulson

This investigation examined the feasibility of altering the inorganic component of North Dakota lignite by ion exchange. Lignite of specific size consist was washed with various ionic solutions and examined for evidence of exchange. Ions of higher valance substituted preferentially at equivalent concentrations. Results indicate that a major portion of the inorganic material associated with lignite is combined in exchangeable form with the organic component. Particle size of the treated coal is a critical factor in determining the rate of exchange. The data indicate that monovalent ions are easily replaced by divalent and trivalent ions, and the presence of ionic material in slurries containing finely divided lignite significantly increases filtration rates.

Jan 1, 1968

By C. M. Mason

The methods currently used by the Bureau of Mines to evaluate the sensitivity, strength, incendivity, gaseous products, and physical properties of explosives and hazardous chemicals are described. Included are the tests used to evaluate explosives which arc certified as permissible for use in underground coal mines.

Jan 1, 1972

By Ludwig Schmidt

This report, the second of a series, presents the results of laboratory corrosion studies which were made in connection with a one-year test on aluminum lease tanks conducted by the United States Bureau of Mines. Part I of the report contains the results of the field teats.5 The studies were made on an oil lease in a so-called "sour district," near Borger, Tag., where free hydrogen sulphide accompanied the production of oil, gas, and salt water. Steel tanks previously used on the lease had suffered severe corrosion, because steel is inherently susceptible to attack by hydrogen sulphide. Because of the high resistivity of aluminum to the action of hydrogen sulphide, it Was believed that this metal had promising possibilities as a material for the construction of lease tanks in "sour districts." The results of the one-year field teat proved that aluminum lease tanks will withstand corrosion by hydrogen sulphide, but it was found that aluminum was susceptible to attack by salt water, which was invariably present in certain portions of the tanks, and that hydrogen sulphide accelerated this salt-water corrosion in an indirect manner, as will be explained hereinafter. In order to study corrosion conditions encountered in the tanks during the test period, a laboratory was maintained at the site of the aluminum lease tanks.

Jan 1, 1931

This report, the second in an annual series, summarizes information on latest technological developments and advances, and identifies trends in mining and metallurgy based on a review of activities in the minerals industry in 1971. Exploration and mining data obtained from an annual canvass are presented for 1971 and are compared with similar data obtained over the past decade.

Jan 1, 1973

By Mah Alla D.

Previously existing heat-of-formation values for the oxides of vanadium were rudimentary. They were subject to uncertainties of 1 to 5 kilocalories per gram-atom of contained oxygen. This fact has been the only adverse influence on the accuracy of thermodynamic calculations involving these substances, as the requisite entropy and high-temperature heat-content data are known with reasonable accuracy. This report presents new heat-of-formation data for four oxides of vanadium (VO, V203, V02, and V205), obtained by combustion calorimetry. It is believed that the uncertainties have been reduced to 0.1 to 0.3 kilocalorie per gram-atom of contained oxygen. The new heat-of-formation data were combined with existing entropy and high-temperature heat-content values to obtain free energies of formation of the four oxides at temperatures up to 2,000° K.

Jan 1, 1961

By G. V. Sullivan

This report summarizes the results of metallurgical investigations by the Federal Bureau of Mines of manganese oxide ore, averaging 23 to 25 percent manganese, stockpiled at the Butte-Philipsburg depot of General Services Administration (GSA). The oxide ores were stockpiled in two general classifications, straight oxide ore and mixed oxide-carbonate ore. Continuous-circuit flotation tests at the Albany (Oreg.) Metallurgy Research Center of the Bureau of Mines showed that each of these ore types could be concentrated by an oil-emulsion scheme to produce a concentrate that could be sintered to meet program specifications. About 88 percent of the manganese was recovered in the concentrate from the straight oxide sample, with the sintered concentrate containing 48 percent Mn. The sintered concentrate from the mixed oxide-carbonate sample contained 41 percent Mn with a recovery in the concentrate of 95 percent.

Jan 1, 1961

By Henry H. Ginsberg

The effectiveness of 0.01 pct. molybdenum, as ammonium molybdate impregnated on coal, on the hydrogenation of a high-volatile bituminous C coal at 8,000 p.s.i.g. and 460° to 480° C. has been studied in a pilot plant by the Federal Bureau of Mines. Under these conditions, the Bureau obtained 98 to 99 pct. conversion5/ of coal to liquids and gases at throughputs of 29 to 101 lb. of m.a.f. coal per cubic foot of reaction space per hour. At 460° C. the indicated yield of oil ranged from 63 pct. (based on m.a.f. coal) at a throughput of 35 lb./c.f.h. (pounds per cubic foot per hour) to 68.5 pct. at a throughput of 58 lb./c.f.h., and the yield of gaseous hydro-carbons ranged from 25.5 to 19 pct. at the same throughputs. The maximum measured yield of oil boiling under 325° C. was 47 pct.

Jan 1, 1960

By J. W. Paul

A superintendent is one who has the oversight and charge of some organiza- tion or enterprise, with porer of direction. The superintendent of a coal mine is the official who is in general charge of conducting the operation of the nine for the purpose of producing coal; he is accountable to his superiors for all matters that relate to the cost of production and safety in operation, ed under him are all the underground officials and other personnel making up the mine organization. The responsibility of the superintendent covers all the principal phases of mining, purchases of materials, issuance of supplies, accounting, and upkeep of the property and equipriont. In a broad sense, the superintendent must view his job as embraced under four gneral heads: (1) Construction, (2) instruction, (3) supervision; and (4) discipline. The degree of efficiency with which each of these phases of his work is conducted is a measure of the safety factor which the superintendent injects into his job. Injury to workmen and damage to property may be due to neglect of one of these general headings; as for example in the collapse of a scaffold there has been faulty construction which may be found upon investigation to have been the result of faulty instruction or lack of instruction. It may be that the condition of the scaffold was not ascertained in advance of its collapse through faulty supervision, or the discipline of the workmen had been neglected.

Sep 1, 1930

By D. E. Wolfson

This report describes the carbonizing properties of the principal coal beds of Allegheny County, Pa., which rank low in the high-volatile A bituminous classification. Seven coal samples from 3 coal beds were selected for study, as follows: 2 each from the Redstone and Pittsburgh beds and 3 from the Upper Freeport bed. Selection was based on estimated reserves. The samples of Upper Freeport and Pittsburgh coals were satisfactory chemically for producing metallurgical coke. The ash contents of the samples of Redstone coal were moderately high. One of the samples of Redstone coal was high in sulfur content, and it would be difficult to upgrade to meet present metallurgical standards.

Jan 1, 1959

By J. M. Davidson

The potassium mineral polyhalite (K2SO4.MgSO4.2CaSO4.2H2O) found in large deposits in western Texas and southeastern New Mexico is associated with varying amounts of halite (sodium, chloride, NaCl) and anhydrite (calcium sulphate, CaSO4). Although the anhydrite, because of its low solubility and slow rate of solution, is relatively inert, the halite is dissolved immediately in any process solution with which the polyhalite comes in contact. Limited quantities of sodium chloride in the liquors used for the hot extraction of polyhalite materially improve the results obtained, but only a very small sodium chloride content may be desired in the entering polyhalite in other procedures, such as Bureau of Mines process. In all of the processes suggested for the recovery-of potassium sulphate from polyhalite the control of the sodium chloride content will be desirable, if not absolutely essential to efficient operation.

Jan 1, 1934