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By Richard D. Miller

This publication contains routine analyses and related source data for 350 natural gas samples from 19 States collected during calendar year 1362 as part of a continuous survey of the United States for occurrences of helium in natural gas. This survey has been conducted by the Helium Activity of the Bureau of Mines since 1917. The analyses published herein were made by mass spectrometer and a special helium analysis apparatus. Four previous publications have been made to present the results of 5,648 gas analyses made by the Bureau of Mines, Helium Activity, prior to 1962. The first, Bulletin 486, 3/ contains analyses and data on 2,195 gas samples collected during the period 1917-47. Bulletin 576, 4/ the second publication, includes data and analyses for 1,575 samples collected from 1947 through May 1956. The third bulletin contains 1,444 analyses and source data of samples obtained from May 1956 to January 1, 1961.

Jan 1, 1964

By Richard A. Allwes

The Bureau of Mines conducted an in-mine case study on two consecutive three-entry gate road systems designed in accordance with the stiff-yield pillar design concept. This Bureau study was conducted in order to further develop technology that will improve the health and safety aspects of longwall mining. Support loading and strata activity were monitored to determine the effects of retreat longwall mining on the gate road ground control system. Analyses of pillar stress and roof bolt loading histories revealed that headgate roof support elements ex-perienced cumulative loading throughout the life of the longwall panel. Tailgate pillar loadings had significantly different histories from the loading histories of the headgate pillars. Stress relief occurred in the tailgate pillars following the passage of the longwall face. More-over, the stiff-yield pillar design, with the abutment pillar placed adjacent to the working panel when part of the headgate system, provided effective ground control in that no major roof falls or roof problems were experienced in the headgate or tailgate systems during longwall mining.

Jan 1, 1985

By NEHA PANDEY, V.K. REDDY KALLAM, SUNIL KUMAR TRIPATHY, ARIJIT BISWAS

This work discusses the sulfur dioxide (SO2) leaching of low-grade ferruginous manganese ores to selectively recover manganese (Mn) as manganese sulfate (MnSO4), followed by electrowinning of the purified MnSO4 to produce electrolytic manganese dioxide (EMD). The effects of the leaching process parameters on Mn recovery were studied, and the leaching duration and SO2 flow rate were found to have significant effects. Under the optimum conditions derived for grade 1 ore (with total Mn content of approximately 17.16 percent), the specific SO2 requirement (SSR) — that is, the SO2 flow rate per gram of Mn in the leach slurry — was calculated to be 0.014 L/min. At the SO2 flow rate calculated using SSR for grade 2 ore (with total Mn content of approximately 26.29 percent), a Mn recovery rate of 94 percent was realized. Electrowinning of the purified MnSO4 generated after leaching resulted in EMD with 88.01 percent purity and a γ structure.

Sep 1, 2022

The panic bars (and associated linkages and electrical circuitry) that are defined in this document are a machine operator-actuated control for the emergency deenergization of the tram motors on self-propelled, electric and diesel face equipment; including haulage equipment such as shuttle cars. There are nine basic types of panic bars (and several variations) that are recommended in this document, but all of the panic bars are characteristically of the ?fire door? type that is frequently encountered on outside exit doors of many public and some commercial buildings. It is also the intent of the following panic bar designs that, when emergency brakes are added to the face equipment machinery for which they are required, that they be designed and hooked up so that actuation of the panic bar will result in automatic application of the emergency brakes (immediately following the deenergization of the tram motors). The following panic bar design requirements are a restatement of the proposed requirements defined in the Federal Register, requirements cited in "Guidelines for the Design and Installation of Devices for Deenergization of Self -Propelled Electric Face Equipment/Automatic Emergency Brake s II by C. E. Lester and J. D. Greenhalgh of MESA, and Bendix recommendations that were formulated as a result of discussions with personnel at the various machine manufacturers and underground coal mines that we surveyed, discussions with G. L. Judy (our consultant), etc:

Jan 1, 1974

By H. L. Burmeister

This report describes the mining and milling practices used by the Eastern Magnesia Talc Co. at its Johnson, Vt., operation. The report also contains a description of the local geology and all available information on cost and performance data. Since 1925 the mine has produced continuously at an average annual rate of 54,000 tons, and the ratio of ore hoisted to finished product is roughly 2 to 1. Ore is stoped by a combination of shrinkage and sublevel methods. In any 24-hour period the mill produces an average total of 14 grades of finished talc product, 9 by dry grinding and air classification and 5 by wet grinding and flotation methods. The mine operates one shift per day, 5 days per week and the mill operates on a 3-shift, 5-1/2-day-per-week basis. Operating costs for 1958, on a percentage basis, were mining, 22.34; milling, 54.77; ore haulage, 2.89; and all other, 20.00 percent.

Jan 1, 1963

By Juan Camus

To understand why some companies excel in creating value, Jim Collins (2001) and a group of postgraduate business students engaged in a comprehensive, five-year research project. They examined 1,435 U.S. companies for more than 40 years, seeking those that made significant improvements in their financial performance over time. The distinctive pattern sought was: ?Fifteen-year cumulative stock returns at or below the general stock market, punctuated by a transition point, then cumulative returns at least three times the market over the next 15 years. ?The search identified 11 outperforming companies, all in different industries, that were called the ?good to great? companies. To contrast these companies with similar peers within the same industry, the search also selected a group of comparison companies that failed to make the leap from good to great. Collins then set out to examine the transition point. What distinguishing features did the good-to-great companies have that their industry counterparts did not? At the heart of the findings about these outstanding companies is what Collins refers to as the ?hedgehog concept? ? how to find the one big thing that the company must focus on. According to Collins, those who built the good-to-great companies were, to one degree or another, hedgehogs. Those who led the comparison companies tended to be foxes, never gaining the clarifying advantage of a hedgehog concept, being instead scattered, diffused and inconsistent. This insight is complemented by Peter Drucker (2004), an influential management guru, who asserts that the first question an effective executive should ask is: ?what needs to be done?? Asking this question and taking it seriously, he asserts, is crucial for managerial success; and that the answer almost always has more than one urgent task, but the effective leader only concentrates on one task. In this last respect, Drucker emphasizes: ?If they [executives] are among the sizeable minority who work best with a change of pace in the working day, they pick two tasks. I have never encountered an executive who is effective while tackling more than two tasks at a time.?

Jan 1, 2011

By H. B. Zhou

The process of bioleaching marmatite using moderately thermophilic bacteria has been studied in this research by comparing marmatite leaching performance of mesophilic bacteria and moderately thermophilic bacteria and valuating the effect of venting capacity on marmatite leaching performance of moderately thermophilic bacteria and the effect of pulp densities on marmatite leaching performance of moderately thermophilic bacteria. The results show that moderately thermophilic bacteria have more advantages over mesophilic bacteria in bioleaching marmatite. Aeration agitation can improve the transfer of O2 and CO2 in solution and promote the growth of bacteria and therefore, enhance the leaching efficiency. With the increase of pulp density, the total leaching amount of valuable metals increased, however, the extraction efficiency decreased due to many rea-sons, like increasing shear force that results in poorly growth condition for bacteria, etc.

Jan 1, 2014

By Richard D. Mehring

A refined ad improved self-sealing brattice for use in coal mine rescue and recovery operations for directing the flow of air has been developed and tested by Goodyear Aerospace Corporation for the U.S. Bureau of Mines. The brattice is made from a lightweight, low cost material that meets MSHA flammability requirements. The units can be erected using pins, spade or lightweight extensible poles. Tests here conducted to determine leakage rate from minimal to a maximum of 1.5" H20. The ability to handle reverse flows was demonstrated and a non-flammable foam was used as an auxiliary sealing agent.

Jan 1, 1978

By P. A. C. De Ruiter

The Lower Cretaceous salt deposits of the Gabon Basin and Congo Basin were said down on ton of an Burly Cretaceous Lato Jurassic, continental graben fill that represent!) the rifting phase of the Afro-American continent. The salt 13 characterized by high percentages of potash and magnesium salts and the scarcity of sulphates and carbonates. The salt probably originated from a brine that was already enriched in high-soluble salts before entering the Gabon Congo basins. Their low-solubility equivalents are found in the Cuanza Basin of Angola. Commercial mining of the potash salt is only possible in those onshore areas where it is essentially undisturbed, shallow and of the right chemical composition. These conditions are net in Congo where the Holle mine produces from rich sylvinite deposits.

Jan 1, 1978

By Q. Cao, A. Pitts, L. Nastac

Accurate prediction of the desulfurization behavior of steel is of great importance for process control during ladle metallurgical furnace (LMF) steel refining. A CFD model capable of simulating multiphase flow with bulk and free surface turbulence phenomena and desulfurization behavior in the gas-stirred ladle has been developed. The fluid flow behavior shows that slag and metal try to entrap each other, forming a two-phase mixing zone. The resulting substantial contact area between the two phases will provide very favorable kinetic conditions for chemical reactions. For reaction kinetics model, the reactions at the metal/slag bath interface as well as the entrapped droplet surface are included. Predicted results show that the sulfur content changing with time in the ladle agrees well with the industrial-scale experimental measurements.

Mar 1, 2017

By N. A. C. Smith, E. W. Dean, W. A. Jacobs, H. H. Hill

Fractional distillation is the most important process in the commercial refining of petroleum. The same procedure, conducted on a small scale, is the basis of a number of analytical methods of wide application in the petroleum laboratory. The Bureau of Mines has studied apparatus and procedure for the distillation analysis of petroleum, and this report is presented as a record of developments up to the present time. The work is incomplete, but the extensive information that has been obtained to date is made available as a guide in handling laboratory distillation problems. The analytical distillation of petroleum is commonly made to determine range of boiling points or to separate the oil. into fractions for detailed examination, or both. When only one of these two ends is sought the procedure involved is notably simpler than when, as is more common, information is required regarding both boiling range and properties of fractions. Moreover the degree of minuteness of measurement and the accuracy of the data required from analytical distillations differ considerably. Often the simplest sort of comparative figures are satisfactory; other tests require complicated and highly tedious procedure. No one distillation method is universally applicable, and it is impossible for anyone group of investigators to foresee all the different kinds of requirements that may occur in the industry.

Jan 1, 1922

By Katerina Adam

During wet grinding the electrochemical interactions between grinding media and pyrrhotite not only accelerate the media wear but also adversely affect the flotation response of the sulfide mineral. A possibility of remedying the adverse effect on its floatability by applying electric potentials to grinding media was examined. Flotation tests, Auger electron spectroscopy and x-ray photoelectron spectroscopy were used to study the surface properties of pyrrhotite. Although anodic polarization of the steels increased the metal loss by corrosion, the flotation recovery of pyrrhotite was increased. In the case of cathodic polarization, the flotation recovery improved in a narrow range of overpotentials. At higher cathodic overpotentials, however, the floatability of the mineral was progressively lowered although the corrosive wear of grinding media might be reduced.

Jan 1, 1984

By John B. Hastings

THE reconnaissance of the Goldfield mining-district, described in this paper, was made in May and June, 1905, and, though this time was too short for a complete report, the work accomplished may serve as a basis for more thorough future research. Dr. Berkey has examined the rocks collected by myself, and I am using his classifications. As a result of further field-work, and Dr. Berkey's examination of the rocks, this paper is an elaboration and correction of my views expressed in the Gold-field Sun, May 12, 1905. The sketch-map, Fig. 1, illustrates the geology of the Goldfield mining-district. Goldfield is an eruptive complex, consisting of alaskite (binary granite), hornblende-andesite, hornblende-dacite, rhyolite, pyroxene-andesite, pyroxene-dacite (sometimes containing, a small quantity of olivine), quartz-felsite, olivine-pyroxene-ande¬site, and basalt. Considering this list to be arranged in the order of eruption, the age-sequence of the rocks conforms to Richthofen's law, formulated in 1868. From his observations in Europe and America, propylite, andesite, trachyte, rhyolite and basalt, occurring together, succeed one another. In a general way, the medium and more acidic rocks precede the most asic-a result supposed by some to have arisen from their relative position beneath the surface, and due to a rude stratification by gravity in the original cooling magma during the older history of the earth, or to the same differentiation occurring during a quiescent (molten ?) period preceding eruption, being aided by the ease with which acidic rocks, mixed with water vapors, become fusible. In effect, the more basic and less re-

Mar 1, 1906

By Frank A. Peters

This Bureau of Mines report is the second of a series of process evaluations planned to determine the relative processing costs of producing metallurgical-grade alumina from low-grade aluminous materials. Included in these evaluations are recommendations for additional research and development to improve the processes and to lower their costs. The design for each process is based on published work. The processes considered in this report are designed to extract alumina as aluminum chloride from calcined clay with 20 percent hydrochloric acid and to remove the silica residue by filtration. Iron is removed by one of the following processes: Isopropyl ether extraction, in which iron chloride is extracted before decomposing the aluminum chloride; gas precipitation, in which the aluminum chloride is precipitated with hydrogen chloride while leaving the iron chloride in solution; gas precipitation-isopropyl ether extraction, in which the aluminum chloride from precipitation is extracted with isopropyl ether, if necessary; caustic purification, in which a crude alumina is produced and then purified by a modified Bayer operation; or sinter purification, in which a crude alumina is produced and then purified by a lime-soda sinter operation. For plants producing 1,000 tons of alumina a day the estimated operating costs per ton of alumina are: [Isopropyl ether extraction process $ 65.09 Gas precipitation process 89.04 Gas precipitation-isopropyl ether extraction process 119.65 Caustic purification process 73.79 Sinter purification process 80.47] The estimated fixed capital costs per annual ton for these plants on a Marshall and Stevens chemical equipment basis of 240.0 are: [Isopropyl ether extraction process $229.03 Gas precipitation process 287.16 Gas precipitation-isopropyl ether extraction process 356.59 Caustic purification process 266.48 Sinter purification process 279.13]

Jan 1, 1962

By P. S. Haury

"INTRODUCTION Many ore deposits were discovered in the Wallapai Mining District, which covers the Cerbat Range in Mohave County, Ariz., during the early period of mining there from about 1865 to the 1890's. A considerable amount of production was obtained from shallow lead carbonate ores that carried considerable gold and silver.Mining was revived in 1906 and again during the First World War, and soma of the mines were deepened into the underlying sulfide zone. Substantial quantities of metal were recovered from two mines, the Golconda and the Tennessee-Schuylkill, that were, developed to depths of 1,600 and 1,400 feet, respectively. The Golconda is credited with $6,500,000 gross productions. 2/ This mine was not operated after 1917. The Tennessee-Schuylkill is still operating after a yield of about 300,000 tons of ore that averaged 4.33 percent lead and 7.74 percent zinc and contained an appreciable amount of gold and silver.Many of the old mines were reopened in 1942 or 1943 under the stimulus of premium prices for lead and zinc. A large proportion of this work was finished with loans from the Reconstruction Finance Corporation. It was believed that a good deal of lead and zinc could be recovered from the mines if a custom mill for concentration of the ores was available locally."

Aug 1, 1947

By Edmund S. Leaver

The selection of a process for treating a gold ore is governed primarily by the characteristics of the ore under consideration. The form in which the gold occurs, its mode of association with other minerals, and the size and surface condition of the gold particles are important factors which influence materially the choice of procedure for recovering gold. A knowledge of these characteristics may be obtained by microscopic and chemical methods combined with experimental testing. Cyanidation and amalgamation, either alone or in conjunction with flotation and gravity methods, are peculiarly adapted to the treatment of gold ores, especially those of relatively low grade. Gold alloys readily with mercury provided both present clean surfaces. The presence of oils and grease, antimony and arsenic minerals, or soluble sulphides have a harmful effect. Very small, flaky particles of gold frequently are lost in amalgamation because of noncontact with the mercury. Fine gold in pyrite, or gold having rusty or contaminated surfaces, is often lost for the same reason. Grinding or some form of abrasion sometimes removes surface films of iron oxide or substances of a similar nature, and alkalies or other chemicals are used to remove grease. Gold is readily soluble in cyanide solution, and this method of treatment is particularly effective in the recovery of gold from the tailings resulting from other types of concen¬tration procedure. Cyanide solutions must contact the gold to insure recovery, and the porosity of the ore treated and the fineness of grinding required are important governing factors. The use of lime in cyanidation is necessary to protect the cyanide, to precipitate undesirable substances, and to settle slimes. Certain substances in ores are harmful in cyanidation; chief among them are those that combine with cyanide, forming cyanides, and carbon which precipitates gold from solution. Arsenic and antimony are also harmful if present in sufficient quantity. These and other difficulties encountered in cyaniding certain ores often are overcome by roasting prior to leaching. Zinc dust is used almost universally for precipitating precious metals from cyanide solutions. The refining and melting of the product may be accomplished by oxidizing the zinc before melting it in graphite pots with fluxes, although sulphuric acid is now used largely to remove the zinc before melting. Straight cyanidaticn practice is being replaced by flotation as a major process, followed by cyanide leaching of the tailings, but amalgamation is still needed as a primary process for the recovery of coarse gold before either flotation or cyanidation.

Jan 1, 1935

By Edmund S. Leaver

The selection of a process for treating a gold ore is governed primarily by the characteristics of the ore under consideration. The form in which the gold occurs, its mode of association with other minerals, and the size and surface condition of the gold particles are important factors which influence materially the choice of procedure for recovering gold. A knowledge of these characteristics may be obtained by microscopic and chemical methods combined with experimental testing. Cyanidation and amalgamation, either alone or in conjunction with flotation and gravity methods, are peculiarly adapted to the treatment of gold ores, especially those of relatively low grade. Gold alloys readily with mercury provided both present clean surfaces. The presence of oils and grease, antimony and arsenic minerals, or soluble sulphides have a harmful effect. Very small, flaky particles of gold frequently are lost in amalgamation because of noncontact with the mercury. Fine gold in pyrite, or gold having rusty or contaminated surfaces, is often lost for the same reason. Grinding or some form of abrasion sometimes removes surface films of iron oxide or substances of a similar nature, and alkalies or other chemicals are used to remove grease. Gold is readily soluble in cyanide solution, and this method of treatment is particularly effective in the recovery of gold from the tailings resulting from other types of concentration procedure. Cyanide solutions must contact the gold to insure recovery, and the porosity of the ore treated and the fineness of grinding required are important governing factors. The use of lime in cyanidation is necessary to protect the cyanide, to precipitate undesirable substances, and to settle slimes. Certain substances in ores are harmful in cyanidation; chief among them are those that combine with cyanide, forming cyanides, and carbon which precipitates gold from solution. Arsenic and antimony are also harmful if present in sufficient quantity. These and other difficulties encountered in cyaniding certain ores often are overcome by roasting prior to leaching. Zinc dust is used almost universally for precipitating precious metals from cyanide solutions. The refining and melting of the product may be accomplished by oxidizing the zinc before melting it in graphite pots with fluxes, although sulphuric acid is now used largely to remove the zinc before melting. Straight cyanidation practice is being replaced by flotation as a major process, followed by cyanide leaching of the tailings, but amalgamation is still needed as a primary process for the recovery of coarse gold before either flotation or cyanidation.

Jan 1, 1935

By B. S. Ignasiak, Dennis Carson

"Laboratory study of the behaviour• of binary coal blends shows that coke strength is more closely dependent on the distribution of ""reactive"" oxygen in the parent coals than on their proximate, elemental or petrographic compositions, and it also appears possible to qualitatively predict coke strength from information about reactive oxygen. Proceeding from this recognition, experiments were carried out to test the possibility of preparing metallurgical cokes from binary blends in which non-caking hvb coal was substantially freed of reactive oxygen by prior heat t1•eatment under controlled conditions. The results indicate that such blends can yield surprisingly strong cokes and that coke strength may be amenable to further improvements by modifying the size distribution of the pre-heated component and the rate at which it is charred."

Jan 1, 1976

By Aline Tatom

This paper presents numerical and experimen¬tal results dealing with the application of ferric ion oxidation of uranium in acidic media. Conclusions are derived from matching numerical results to experimental data taken on one-dimensional laboratory leaches using ore from a South Texas Coastal plain deposit. Since the numerical results can be made quite general, we are able to extract and quantify the effects of oxidant concentration, flow velocity, mass transfer, chemical kinetics, and competitive oxidant consumers (pyrite and molybdenite) on the experimental results. Our results suggest that the leaching of uranium is a mass transfer controlled while that of pyrite is kinetically controlled.

Jan 1, 1981

By S Hall

Mining schools around the world, many unfortunately now closed, were often established to teach the techniques of narrow vein mining and associated processing to students studying part-time while working in the industry. This arrangement ensured graduates (or æassociatesÆ) had a mix of skills and knowledge invaluable to the industry.It is argued that there is still a need to educate students in these narrow vein techniques and that there will be a growing demand for such graduates with a high level appreciation of this type of mining. There is also a need for innovation in narrow vein mining and processing to develop specific technologies and allow the use of techniques applied in æbulk miningÆ to achieve improvements in productivity, safety and economic performance.This paper aims to review the situation with regard to education and innovation in narrow vein mining.CITATION:Hall, S, 2012. Narrow vein education - back to the future?, in Proceedings Narrow Vein Mining 2012 , pp 23-26 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012