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By Dale W. Richardson

Ductile hafnium was not obtained consistently by the conventional Kroll process. The bimetal reduction modification produced a more ductile hafnium by lowering the impurities, especially oxygen, in the sponge metal. Hafnium oxide was chlorinated in the presence of carbon to form anhydrous hafnium tetrachloride, which was reduced by sodium and magnesium in an inert atmosphere to produce sponge hafnium metal. After vacuum distillation to remove the byproducts, the sponge was arc-melted into ingot and rolled into strip. Metallic impurities were decreased by evaporating the hafnium tetrachloride from a fused salt. An excessive amount (over 1,200 parts per million (p.p.m.)) of aluminum was contained in some of the hafnium oxide, much of which remained as aluminum chloride in the hafnium tetrachloride during chlorination. Evaporation of the hafnium tetrachloride from a fused NaCI-KCI mixture during the Mg-Na reduction greatly lowered its aluminum content, as most of the aluminum and some of the other metallic impurities were retained by the fused salt.

Jan 1, 1961

By D. L. Pitt

This paper, describing the milling methods at the concentrator of the Premier Gold Mining Co., Ltd., Premier, B. C., Canada, is one of a series being prepared by the United States Bureau of Mines on milling methods and costs in the various mining districts throughout the United States and Canada. ACKNOWLEDGMENTS The authors wish to acknowledge the assistance and suggestions given during the preparation of this paper by the engineering staff and accounting department of the Premier Gold Mining Co., Ltd., all of whom have assisted materially in gathering the data used.

Jan 1, 1933

By Jingcheng Li

Currently many underground coal mines worldwide have installed or been planning to install a tracking system to trace miners mainly for their safety. Although many systems have been reported functional, a lack of sophisticated and systematic error correction methods apparently is still an issue for them; often it results in a low system resolution. To improve the system resolutions, this paper introduces two position adjustment methods for mine tracking systems. The first is an entry-matching method that optimally adjusts an off-course tracking device to the closest tunnel (entry). The second is a distance measurement adjustment method that accurately adjusts the position of a tracking device along an entry according to a measured distance from the device to a reference point. The coplanar node-path network mine model is used as the foundation for the development of these two methods.

Jan 1, 2009

By M. R. Yenchek

The Bureau of Mines conducted research to determine the relationship between cur-rent load and temperature rises in coal mine trailing cables. Six low-voltage, unshielded, portable power cables were continuously and intermittently loaded with direct current of various magnitudes. Temperature rises within and on the cables were measured with thermocouples, and the data were recorded with a computer. Thermal time constants were calculated, which fixed the periods of the duty-cycle tests. Relationships between average temperature at the conductor-insulation interface and current load were established. The steady-state and intermittent currents that produce a 90° C average conductor-insulation temperature were then determined. Comparisons with Insulated Cable Engineers Association (ICE A) steady-state ratings revealed that 10 to 25 pct more current than recommended ICEA ampacities is required to reach rated insulation temperature. Examination of the maximum intermittent temperatures attained showed that autoignition of coal dust and burn injuries to personnel handling the cable would not be concerns if the temperature at the conductor-insulation interface averaged 90° C.

Jan 1, 1988

By Guy B. Taylor, Horace C. Porter, E. C. White

When the Federal investigation of coal - dust explosions in mines was begun in 1908 , following a series of mine explosion disasters in 1907 , mining men generally questioned whether coal dust in air is explosive unless " gas " or methane is present , though perhaps in small amounts not detectable by a safety lamp . The experimental tests beginning in 1909 at the Pittsburgh testing gallery, and after 1911 , at the Experimental mine , demonstrated to the mining public the explosibility of coal dust in itself . There followed much controversy , both among practical mining men and scientists , as to whether the coal-dust particles uni te directly with the oxygen of the air, or whether gas is instantaneously distilled from the dust prior to explosive combustion , the gas enveloping each particle and propagating the flame from one to another . In considering methods of preventing explosions , this question made no difference for practical purposes , but it did have bearing in determining the relative inflammability of dusts of different coals . This led to the experiments by Guy B. Taylor and Horace C. Porter , on the momentary heating of the inflammable coal dusts , reported in this paper . Meanwhile , experiments on the inflammability of coal dust conducted in the Experimental mine , under my direction , and in the laboratory by J. C. W. Frazer and later by J. K. Clement and J. N. Lawrence , showed that different kinds of coal dust differ markedly in inflammability , thus confirming experiments made by Messrs . Taffanel and Durr at the Lievin Testing Station , France , and by various investigators in Great Britain . Both the French and British investigators concluded that their experiments demonstrated the distillation of volatile matter preceding inflammation .

Jan 1, 1922

By H. R. Shell

The work on synthetic mica and related subjects is being reported in a series of technical articles (see Supplementary Bibliography), each of which describes some special aspect of the subject. This is the final report on chemical analysis of the fluoride-containing silicates. A condensation of this report has been published (26).3/ Chemical analysis affords one of the best means of ascertaining the final com-position of either a heterogeneous mass or a single pure crystal, particularly where some constituents may be volatile. The analysis of fluoride-containing silicates was not so well known or understood that highly accurate results were commonplace. For example, on synthetic mica a university laboratory reported 11.6 and 9.2 percent fluoride when at least 13.3 and 11.3 percent were present, respectively; a commercial testing laboratory reported 9.14 percent as compared to 12.6 percent; and a glass company reported 7.0 percent as compared to 9.0 percent present. No intimation is made that these analysts could not have done better, but the point to be stressed is that the methods in use were long, tedious, and generally required a certain familiarity for best results.

Jan 1, 1956

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Jan 1, 2008

By D. E. Pollock, Andrew B. Cecala

It has long been known that ventilation is a cost-effective method to lower respirable dust concentrations in all types of mining applications. The National Institute for Occupational Safety and Health has been working on a number of different research techniques that use ventilation as a critical component to lower respirable dust levels at surface and metal/nonmetal operations in the United States. This article presents five such research efforts. The first research area discusses how improving the ventilation flow patterns in an iron ore mill facility lowered respirable dust concentrations by 31 pct throughout the primary grinding area. The second research area examines how respirable dust levels were lowered at a dimensional stone shop by using air cleaning units suspended from the ceiling. A third area discusses how improvements in ventilation at underground limestone mines lowered respirable dust concentrations. The fourth area examines how improvements in dust filtration and pressurization systems significantly impacted the air quality in enclosed cabs of surface mining equipment. The last area presents a newly developed clothes cleaning technique. This technique uses an air spray manifold to blow dust from a worker’s clothing in an enclosed booth, which confines the dust for capture and removal by a baghouse dust collector. These research areas represent an array of different control technologies to lower respirable dust concentrations. Ventilation is an integral part of these control technologies.

By N. Fragen, H. H. Stroch

"INTRODUCTION A previous paper by H. H. Storch 4 described. three processes for the production of potassium sulphate from polyhalite (K2S01.MgSO1.2CaS04.2H2o), Since these processes depended upon calcination of polyhalite followed by leaching with water at 100°C., the fundamental reactions occurring in these steps were discussed in detail. This paper, which describes processes producing syngenite (K2S04.CaSO4.H2O) and potassium sulphate and gives data concerning the production of by-product magnesia, presents the results of work performed at the Non metallic Minerals Experiment Station of the U. S. Bureau of Mines, maintained at New Brunswick, N. J., in cooperation with Rutgers University.A study of the solubility relationships of the system 5 Ca++ -Mg++ -K+-SO4 = H20 at 25ºC. shows that syngenite is stable in the presence of a concentrated MgSO4 solution, the K2SO : equilibrium concentration being comparatively low (2.6 per cent), The processes described below, which involve the conversion of calcined polyhalite to syngenite, are based on the 25°C. equilibria. It has further been found that syngenite can be decomposed by water at 100ºC, yielding a 9 to 10 per cent K250 solution, the solid phase being potassium calcium pentasulphate (K2SO, 3CaSO.H2O, hereafter referred to as ""pentasulphate""). This latter compound is unstable in the presence of water at 25°C., its decomposition resulting in a solution containing about 3 per cent of K2SO4 and a solid phase consisting of gypsum. This behaviour of syngenite with water at 100°C. and of pentasulphate with water at 25ºC. constitutes the basis of processes for the production of K2SO4 by way of the conversion of calcined polyhalite to syngenite,Syngenite is a product which may be used as a fertilizer per se. As produced in the process to be described, it contains about 50 per cent of K2SO1, and will readily give up its potash content on treatment with water, although the limiting concentration at ordinary temperatures is approximately 3 per cent. This definite but limited solubility should make this product more desirable as a fertilizer then the more concentrated forms of potash salts which have higher solubilities and hence involve the danger or plant injury due to a high local concentration of potash."

Sep 1, 1931

By A. B. Cecala

It has long been known that ventilation is a cost-effective method to lower respirable dust concentrations in all types of mining applications. The National Institute for Occupational Safety and Health has been working on a number of different research techniques that use ventilation as a critical component to lower respirable dust levels at surface and metal/nonmetal operations in the United States. This article presents five such research efforts. The first research area discusses how improving the ventilation flow patterns in an iron ore mill facility lowered respirable dust concentrations by 31 pct throughout the primary grinding area. The second research area examines how respirable dust levels were lowered at a dimensional stone shop by using air cleaning units suspended from the ceiling. A third area discusses how improvements in ventilation at underground limestone mines lowered respirable dust concentrations. The fourth area examines how improvements in dust filtration and pressurization systems significantly impacted the air quality in enclosed cabs of surface mining equipment. The last area presents a newly developed clothes cleaning technique. This technique uses an air spray manifold to blow dust from a worker?s clothing in an enclosed booth, which confines the dust for capture and removal by a baghouse dust collector. These research areas represent an array of different control technologies to lower respirable dust concentrations. Ventilation is an integral part of these control technologies.

Jan 1, 2006

By T. M. Garland

A nomographical approach is proposed as a fast, easy-to-use, and reason- ably accurate method for estimating expected discounted cash flow (DCF) rate of return and payout time for onshore development drilling and oil production. All costs pertaining to drilling, completing, and equipping development wells, annual expenses of operation, maintenance, and taxes incurred in producing properties, and crude oil prices were considered in developing the nomographs. This report briefly outlines the origin, derivation, and use of the nomographs.

Jan 1, 1973

By B. E. Blair

"This report presents the physical properties and related geological and petrographic data of some 84 rock types from operating mines, quarries, or blasting research test sites. These fundamental rock data were collected as a quantitative approach to underground mining problems, blasting research, or other related studies; however, the data are equally applicable to any problem wherein rock characteristics are important factors. Stress-strain curves are given where available, and the standardized procedure for determining elastic constants from static tension tests is described. Computed (laboratory) and measured (field) free-medium velocities are compared in those instances where such data are available. A chart is given showing both the optimum and minimum number of test specimens for the various core sizes employed in the Bureau of Mines standardized physical-property tests. Rock-type, geographical, and geological indexes are included to aid the reader in locating physical-property data in this and previously published Bureau of Mines physical-property reports.INTROD'OCTI ONThis report presents the physical properties of 84 rock types tested from 16 different projects (sections 37-52). Two previous physical-property reports 2-3 / (hereinafter referred to as parts I and II) presented data on 160 rock types from 36 different projects (part I, sections 1-25 and part II, sections 26-36).The physical-property data were originally obtained to supplement structural mining problems, seismic studies, or related investigations; however, they should be equally applicable in all fields of studies where the strength, hardness, or other properties of rock are important factors. The properties, determined from laboratory tests performed on diamond-drill core, include the following:"

Jun 1, 1955

By G. L. Oldright

The Metallurgical Branch of the Bureau of Mines, as a part of its duties under the Organic Act, works to prevent wastes in industry and to disuse inmate information on the fundamentals of metallurgical processes. During the war, the necessity of large production was increasingly emphasized. Such duties necessitate from time to time the study of units of full commercial size, the operation of which is beyond the facilities of the Branch. When developments have reached this stage; work has been continued in cooperative agreements with operating companies that have been willing to contribute the use of their plants and staffs and to allow the publication of the results obtained for the common good of the industry.

Jan 1, 1948

By S. L. May

Procedures for separating columbium and tantalum have been developed by the Bureau of Mines as part of a broad research program on the utilization of low-grade ores of columbium and tantalum, Columbium and tantalum compounds of greater than 99 percent purity have been obtained by application of the solvent extraction separation system: Hydrofluoric acid-sulfuric acid-methyl iso-butyl ketone. This system is unique in that it not only separates columbium from tantalum, but also separates these two metals from other metallic impurities. The system is effective for separating the metals irrespective of the tantalum and columbium ratio of the starting materials. Investigations in which the spent feed obtained from the initial coextraction step was recycled to the system indicated that efficiency was increased, and cost was reduced without impairing product purity. Continuous tests demonstrated that this solvent extraction system could be used in large-scale equipment without loss in efficiency or in purity of products. The separation of columbium and tantalum has been difficult because of the similarity in their chemical bahavior. Many methods have been proposed for separating these two elements, but most methods either did not achieve satisfactory separation or were tedious and time consuming. The Marignac process (3, 4)4 developed in 1866 was the only method used commercially until recently. This separation procedure is based on the difference in solubility in aqueous solution of potassium tantalum fluoride and potassium columbium oxyfluoride. Current commercial practice appears to favor solvent extraction as a method for separating tantalum from columbium (1). Several efficient methods for separating columbium from tantalum by solvent extraction (2, 9, 8) were reported earlier from this laboratory.

Jan 1, 1961

By Allen McComas, Frank Chase, Phyllip Worley

Longwall mining has gained the reputation as being the safest extraction method in underground coal mines. However, one of the most difficult tasks associated with longwall mining is moving the face once a panel is completed. Based on Mine Safety and Health Administration (MSHA) fatality reports since 1996, longwall face recovery operations have claimed the lives of 5 U.S. miners and have resulted in numerous injuries. Recovery operations can be hazardous because they involve moving large pieces of equipment in very confined spaces. They are also conducted in highly stressed ground conditions due to front abutment loads generated by panel extraction. Shield removal is the most hazardous operation during face recovery because miners are constantly exposed to the unpredictable gob edge. To protect the miners, one or more walking shields, cribbing and/or other supplemental roof and standing supports are typically employed as breaker line supports as each shield is removed. At the Harris No. 1 Mine in southern WV, mobile roof supports (MRS’s) have been used in lieu of traditional walking shields on 17 face moves since 1997. MRS’s are shield-like support units mounted on crawler tracks and are commonly used during room-and-pillar retreat mining operations. For longwall recovery, the two biggest advantages that MRS’s have over traditional walking shields are that they are remotely controlled and are highly maneuverable. MRS’s have contributed to safer shield recovery and shorter move times at the Harris No. 1 Mine. This paper will address both the safety and the operational issues associated with MRS usage during shield recovery. It will also discuss new developments, including the use of the inherently safer battery powered MRS’s, which have been recently certified by the Mine Safety and Health Administration.

By Gordon E. Fletcher

This Bureau of Mines report outlines the atomic absorption analysis of oilfield brines for barium, calcium, copper, iron, lead lithium, magnesium, manganese, potassium, sodium, strontium, and zinc, using the method of additions. The advantages of using atomic absorption are discussed. The method of additions was chosen to overcome large matrix interferences usually found in brines; techniques of overcoming chemical, ionization, and background interferences are also described. The method was used to analyze several hundred oilfield brines and found to be rapid and reasonably accurate. A solvent extraction method was used to concentrate lead, copper, zinc, and iron in low-level samples.

Jan 1, 1974

By R. C. Buehl

Pilot-plant tests have been in progress at the Bureau of Mines, Pittsburgh, Pa., on the recovery of manganese from open-hearth slag.3/4/5/ In the process, 1 the slag is first reduced in a blast furnace to make a high-phosphorus spiegeleisen containing 12 to 22 percent manganese. A slag containing 55 to 60 percent manganese is made from this spiegel by oxidation in a basic-lined converter. The metal from this blowing operation contains about 3 percent phosphorus, 1 percent manganese, and less than 1 percent carbon. Economic efficiency in the manganese-recovery process requires that this metal be converted into steel. Because of its high phosphorus content the metal is suitable for blowing in a basic-lined converter. In most of the tests described in this report, metal of this composition was used as the starting material in a 1-ton, side-blown, basic-lined converter. Although basic-lined converters are not used for steel production in the United states, in Europe a considerable portion of the steel is made in them. Open hearths largely have replaced converters for steelmaking in the United States; mainly because open-hearth steels have better physical properties than converter steels because of lower nitrogen and phosphorus contents. However, by improving converter design and operating technique during the past 15 years, metallurgists have found that low-nitrogen steels with physical properties equal to open-hearth steels can be produced in converters.6/ Tests at Jones & Laughlin steel Corp. with side-blown, acid-lined converters of 3 and 22 tons capacity showed that steel with a low nitrogen content comparable to that of open hearths operating on scrap charges could be made by surface blowing.7/

Jan 1, 1955

By R. H. Storch

"A preliminary examination of the Bi-Metallic molybdenum prospect was made in October 1944, as a result of which it was recommended that a trench exploration project be undertaken on the property. This report presents the information obtained from project work done during June 1945.In its program of exploration of mineral deposits, the Bureau of Lanes has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to the national security and. economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director.With respect to this report, special acknowledgment is due S. H. Lorain, chief, Albany Division, Mining Branch, for aid in preparing the report.The property is situated in the NW1/4, sec. 26, T. 39 N., R. 29 E. about 21 miles northeast of Tonasket. Tonasket (population 643), the nearest town, is a way point on a branch line of the Great Northern Railway. The prospect is reached by a good gravel road through Havillah to Vincent's ranch, about 3 miles northeast of Havillah. From the ranch, an abandoned dirt road extends to the portal of the Moly alit, about 1 mile distant. The mine road could be kept open without difficulty if properly graded and surfaced."

Aug 1, 1946

By Roy J. Greenfield

The overall purpose of this research was to improve the understanding of how the post disaster seismic location system works, what determines the signal size, what is the character of the seismic noise, how well the system can detect blows from a trapped miner, and how well the source of the blows can be located. Based on an improved understanding of the system, improvements were suggested in the seismic subarray configuration, and in the system deployment procedures. An important part of this research was to become familiar with the seismic system operation and to work with the Westinghouse Electric Corporation and MSHA personnel to modify and improve the system. To accomplish this we participated in the planning, execution, and data analysis for a number of seismic field tests. Several in-mine field tests were conducted. From these tests the capabilities of an in-mine seismic system were analyzed and specifications were made for designing an operational in-mine system. Several portions of the work done on this grant were covered in previous reports. In particular the capabilities or the presently operational surface based seismic location system has been thoroughly documented by Durkin and Greenfield (1981). Portions of the location procedures and effects of mine openings on seismic signals have also previously been published. These portions or the work will only be summarized in this final report.

Jan 1, 1982

By J. R. Soule

"The fluorspar deposits in the Gallinas Mining District, Lincoln County, New Mexico, were examined early in February and again in April 1943 by the Bureau of Mines because of the possible importance of newly discovered deposits and of old mine workings showing fluorite-bearing material. There &re many of these deposits spread over a considerable area, and it appeared that exploration might indicate sufficient reserves to support a local mill that could contribute to the supply of fluorspar needed for war purposes. Accordingly, the Bureau initiated an exploratory program in June 1943, which was completed in August 1944.H. E. Rothrock, Roy Earhart, R. G. Smalley, and V. C. Kelly, geologists of the Federal Geological Survey, began mapping and studying the district in May 1943 and continued this work throughout the Bureau's exploration.David J. Stauffer, district ranger, U. S. Forest Service, and several claim owners assisted in the examinations and subsequent exploration.The fluorspar deposits in the Gallinas Mountains are reached by an unpaved forest road, which, leaves U. S. Highway 54 half a mile south of Gallinas station. The road runs due west for 3 miles, then turns due north just beyond the first cattleguard. This north branch is followed for 2 miles to a second cattleguard. There a left branch extends northwest up Red Cloud Canyon to the Red Cloud, and. All. American deposits; the right branch continues north for 2.miles past the Wade Porter ranch, to another left branch, which goes almost 2 miles west to the Hoosier Group deposits. The remaining deposits are reached by trail from either the Hoosier Group or, more easily, from the Red Cloud claim (fig. 1).The Hoosier Group is in sec. l9,, T.. 1S.,1 R. 12 E.; all of the other known ore occurrences are in secs. 13, 14, and 23 to 27, inclusive, T. IS., R. 11 E. All of the deposits are in the Lincoln National Forest and within the limits of a State game refuge. The nearest railroad loading point is Gallinas, Station on the Southern Pacific Railroad. Corona, the next station north of Gallinas, is a Mile or two farther from the deposits.Minor supplied, telegraph, telephone, freight, and express service, and limited living accommodations, Are, obtainable at Corona, 10 to 15 miles from the deposits of Carrizozo, N. Mex., 50 miles south."

Apr 1, 1946