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By James E. Norman

[The flotation of mica is mentioned frequently in the literature, but must of the references have dealt with the recovery of mica by the old anionic collectors. The first use of the new cationic reagents indicated their superiority- as collectors in the flotation and a. agglomerate tabling of micas, feldspars, quartz, clay, and other acidic mineral, but the separation n of these minerals from each other necessitated study of the flotation of each mineral.]

Jan 1, 1941

By James E. Norman

[The flotation of mica is mentioned frequently in the literature, but most of the references have dealt with the recovery of mica by the old anionic collectors. The first use of the new cationic reagents indicated their superiority as collectors in the flotation and agglomerate tabling of micas, feldspars, guartz, clay, and other acidic minerals, but the separation of these minerals from each other necessitated of the study of the flotation of each mineral.]

Jan 1, 1941

By C. J. H. Brest van Kempen

The objective of this contract was to provide thrust and torque control and visual output torque readout systems to an existing mine roof bolting machine and to test the consistency of torques obtained under actual field conditions. A Lee Norse TD1 roof bolter was modified by adding a simple torque sensing device to the drill rotation mechanism and a pneumatic logic control circuit that measures torque and controls the hydraulic circuit to the rotation motor. The modification controls and indicates the final installation torque of mine roof bolts. A total of over 5,000 mechanical roof bolts were installed in an operating coal mine. The installed torque of these bolts were within an error band (standard deviation) of 8%.

Jan 1, 1978

By E. P. Youngman

This paper presents one of a series of digests of foreign mining legis- ation and court decisions that is being prepared in advance of a generel report elative to the rights of American citizens to explore for minerals and to own nd operate mines in various foreign countries. This interpretation of the laws of Demark and her possessions, has been prepared entirely from answers made by Ernest L. Ives, American charge d'effaires, Copenhagen, to a questionnaire ini- isted by the United States Bureau of Mines and transmitted through the courtesy of the Department of State.

Jun 1, 1932

By E. A. Ziemba

The modified in-situ process is one of the methods being considered for extracting oil from oil shale. One of the questions to be answered for this approach is the environmental consequence of underground retort abandonment. This report outlines a study which addresses the question in terms of a grouting solution. It covers the development of a spent shale ash based grout which will fulfill the environmental requirements in terms of strength, stability, and impermeability. In addition, it will allow the reinjection of up to 50 percent of material mined and surface retorted as part of this process.

Jan 1, 1982

Exposure to airborne respirable crystalline silica dust can lead to silicosis, a debilitating lung disease. On surface coal mining and construction sites, blast hole drills are notorious sources of airborne respirable dust that may contain significant amounts of silica. The drill operator and drill helper usually receive the greatest silica exposure compared with other occupations. As a result, many drilling operations have been, and still are, on more stringent dust standards. Drilling through various rock formations naturally presents a strong potential for silica dust generation for several reasons. First, drilling is a pulverizing process that generates large amounts of very small dust particles. Second, the bailing air used to flush cuttings from the hole leaves the hole at a very high velocity and can be difficult to contain. Third, many fixed shrouds used to enclose the area beneath the drill deck have a significant amount of leakage due to 1) gaps between the shroud and ground created by raising/leveling the drill, 2) gaps in the corner seams, and 3) tom deck shrouds. CONTROLS A dry dust collection system is typically connected to the drill deck to collect dust as the bailing airflow transports the cuttings (and significant amounts of airborne respirable dust) out of the drill hole. Deck shrouds are installed in an attempt to enclose the volume around the drill steel and prevent dust escaping. However, most deck shrouds are rectangular and constructed of four separate pieces of rubber belting attached to the deck. Because of this design, there is usually a significant amount of dust escaping from the open seams as well as the open area between the shroud and the ground. This dust can be a significant source of silica exposure to drill operators as well as other personnel downwind of the drill.

By Sabri Ergun

NEW theoretical data are presented for the intensity of X-rays diffracted from randomly oriented aromatic and alicyclic molecules and diamondlike structures such as are found in coals, cokes, and carbonaceous materials. Data have been computed using the Debye interference function. Computations for the smaller molecules have been made with the Univac 1204 computer: those for large structures, with either the IBM 704 or Bendix G-20 computer. A brief theoretical introduction of the Dobye interference function is given, and an outline is made of the treatment of experimental data so that the experimental interference function can be obtained.

Jan 1, 1965

6784. Barnes, V. L., and Romberg, Frederick. Gravity and Magnetic Observations on Iron Mountain Magnetite Deposit, Llano County, Tex. Geophysics, Menasha, Wis., vol. 8, No. 1, 1943, pp. 32-45. An outcrop of magnetite in the Central Mineral region of Texas is explored experimentally with a dip needle and a gravity meter. Two anomalies are observed, one due to the outcropping body and one probably due to a previously unknown body close to the outcrop. The possible attitudes of the bodies are discussed, and their masses and probable dimensions are computed from the gravitational observations. - Author's abstract.

Jan 1, 1943

By Charles M. Keenan

THIS PUELICATION lists and provides brief accounts of the major disasters not classified as explosions of gas or dust that have occurred in the cod mines of the United States from the earliest times to the present. Together with an earlier publication of the Bureau2 it provides information on all the known major coal-he disasters (disasters causing five or more deaths) in this Nation's history. Sources of each account are given individually. In each account the actual words of the original publication are used unchanged, but sentences or paragraphs referring to details that are not significant have been omitted. In those few cases where conflicting data were reported in different publications the selected version is the one that appears most logical and which in general is in agreement with most of the other accounts.

Jan 1, 1963

By Francis C. Lincoln

"INTRODUCTION As part of a general investigation of the zinc-producing area of southwestern Wisconsin, the Bureau of Mines undertook a limited amount of exploratory drilling in the immediate vicinity of the New Dale Rundell mine, in the Mifflin District of Iowa County, Wisc.The work was carried out during the early part of 1945, at a time when all effort was being directed toward increasing production of metals important to the Nation's war program. Bureau of Mines engineers decided to conduct exploration at the New Dale Rundell mine after a preliminary study of available data showed a reasonable possibility of indicating an important deposit. Before the Bureau of Mines investigation, 50 holes had been drilled in the vicinity. Of this number, 18 encountered ore of minable grade. Subsequently the mine was developed and operated for a brief period; however, work was stopped before all of the ore disclosed by drilling had been mined. There appeared to be a correlation between the ore shown by the drilling in the New Dale Rundell mine and another disclosure some 1,500 feet to the northwest. The Bureau of Mines exploration was pinned to explore this possible correlation. Of the 7 holes drilled by the Bureau of Mines, 3 disclosed minable ore beyond the limits of previous drilling."

Aug 1, 1946

By Benjamin W. Haynes

This Bureau of Mines publication comprises a compilation of the state of the science in Pacific Ocean manganese nodule mineralogy and elermental composition. The report is divided into three sections: morphology, mineralogy and elemental composition. The nodule morphology section defines what is considered a nodule for the study, and details the external characteristics and internal structure. Nodule mineralogy is discussed in three sections: manganese minerals, iron oxide minerals, and accessory minerals. The major manganese minerals discussed are todorokite, birnessite, and vernadite. The iron oxide minerals are less well known and include feroxyhyte, goethite, and lepidocrocite. Accessory minerals present include quartz, clays, and other silicates and nonsilicates. A discussion on moisture content is also included. The elemental composition section presents data on 74 elements occurring as cations or anions. Summary data, histograms, and interelement correlation coefficients are presented. The elements are grouped as follows: major and minor elements of potential economic interest (8), other major and minor elements (9), elements of environmental interest (8), rare-earth elements (15), precious-metal-group elements (6), radioactive elements (3), other trace elements (17), and anion-forming elements (8). Cross sectional determinations of Ni, Cu, Zn, Co, Pb, Fe, Ce, and Ba are given for a single nodule to show the general tendency of different growth patterns within a nodule because of different element associations and composition.

Jan 1, 1982

By G. Stecklein

This report summarizes the results of research into the areas of the fragmentation and entrainment of Airborne Respirable Dust (ARD). The objectives of this program were four-fold: first, to review the present state of knowledge regarding ARD; second, to expand this state of knowledge through the identification of hypothetical microscopic mechanisms by which the coal is fragmented and the dust becomes entrained; third, to specify the informational requirements to verify or nullify these hypotheses; and fourth, to relate experimental techniques that will produce that required information. Additionally, insights are provided regarding potential methods of extraction and/or treatment which may reduce the concentration of ARD.

Jan 1, 1982

By Leonard Obert

THE CRACKING AND POPPING of rock, often heard by men working underground, for years has been interpreted as a warning of danger and unstable ground. However, not until 1939 was it discovered that rock under stress generates subaudible and sometimes audible seismic disturbances (referred to as "micro-seismims" 4), which can be detected with the use of a suitable seismic apparatus. Since that date laboratory and field investigations have been in progress to ascertain to what extent this phenomenon can be utilized to detect, localize, and determine the magnitude of areas of instability in and around mine openings and to predict if and when failure will occur. These investigations have included a determination of the types of problems to which the method is applicable and the effect of rock type, geological defects, such as joints, fractures, faults, and other uncontrollable factors, on the reliability of results. Six reports have been prepared covering the investigations conducted between 1940 and 1952 (4-9). 5 These reports describe some of the characteristics of micro-seismims, as determined from both laboratory and field tests; the equipment used to pick up and record micro-seismims; the general test procedure and method of analyzing results; and applications of the method to specific mining problems.

Jan 1, 1957

By M. C. Malamphy

A general description of the activities and results of bauxite investigation by the Bureau of Mines at its bauxite project in Saline and Pulaski Counties, Ark., has been given in Report of Investigations 4251. The factual data obtained during the project are reported in a series of Reports of Investigation beginning with No. 4251, of which this is the ninth. The data are accompanied by maps showing the location of holes drilled and the deposits developed. Each area upon which work was done is reported by half townships. Each bauxite deposit investigated was assigned a name and a number for ready reference and identification, and its location and name are shown on the appropriate half-township map. The description of each half township is followed by a description of each deposit developed in that half township map. The 14 half-township maps and 77 detail maps of the bauxite deposits in this series of reports give the locations and numbers of all the holes drilled on the project except the deep holes drilled to test the geophysical anomalies. The locations of those holes show on figure 13 in volume 1. The descriptions of the deposits developed are followed by complete detailed logs of the drill holes. Many of the widely spaced exploratory holes did not discover bauxite of minable thickness and grade. The pertinent information obtained from the widely spaced exploratory drill holes has been summarized and tabulated, and a table for each half township is given with the discussion covering that area.

Jan 1, 1948

By Daniel E. Sullivan

This Bureau of Mines publication examines the potential impact on minerals of the tariff and nontariff agreements that resulted from the Tokyo Round of the Multilateral Trade Negotiations, which were conducted under the auspices of the General Agreement on Tariffs and Trade. These agreements will affect minerals by reducing tariff levels and by changing rules by which they are traded internationally.

Jan 1, 1981

By H. W. C. Prommel

The increase in the price of gold in 1933 was the cause of starting many activities in gold prospecting and mining; it led to investigations of many of the so-called desert placers in the Southwest, which heretofore had not been deemed of commercial importance. Among these, attention was called to some of the gravel beds in the vicinity of the Randsburg-Atolia mining districts of Kern and San Bernardino Counties, Calif., in which gold and scheelite, (calcium tungstate, CaW04) were said to be present. Following a partial sampling and testing of the gravel, large-scale operations were begun in 1935. During the same year more detailed sampling and testing of the gravel beds were done by the author. During 147 days, 1,239 test holes 28 inches in diameter were drilled; their total depth amounted to 16,705 feet. These test holes furnished 2,495 samples of an average volume of 1.0583 cubic yards bank run each; all of the material was run through a sample mill constructed on the property. Original and rather unusual sampling and testing methods had to be used; milling and mining methods for large-scale operations also offered difficulties. The primary purpose of this drilling and sampling campaign was to determine, over a large area, the amounts of gold and scheelite recovered by placer methods such as were already in use on the property. This paper describes sampling and testing methods employed by the author during the 1935 drilling campaign. LOCATION The gold and scheelite placer deposit is in the Atolia tungsten mining district about one-half mile west of the small mining town of Atolia and about 5 miles south of Randsburg in the Randsburg gold-mining district. The deposit lies near the foot of the Rand Hills, in the Mojave desert. The territory is served by hard-surfaced roads from the north and south; Los Angeles is 150 miles to the southwest. A branch of the Southern Pacific Railroad passes within 5 miles of Randsburg.

Jan 1, 1937

By S. J. Aresco

The Bureau of Mines has been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the ash-softening temperature, the free-swelling index, and the Hardgrove grindability index. Under most of these specification contracts the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions4/ issued by the Bureau of Mines; the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor and, if it is not, a price adjustment is made. Analyses of the delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous .sampling of coal as delivered is a check on the practical results obtained in burning the coal.

Jan 1, 1958

By E. P. Youngman

The mining law of British North Borneo is entitled " The Mining Ordinance , 1927. 113 The only mining regulation or rule available is " Rules 313 , 114 passed in accordance with article 26 of the ordinance of 1927. Before the passage of this legislation , the country had no specific law governing the granting of mineral rights , although the land law contained provisions relating to mining lands . The land ordinance of 19135 still controls in a few details . All references in this paper , unless otherwise specifically designated , are to the mining ordinance .

Mar 1, 1933

By Michael S. Miller

In 1985 and 1986, at the request of the U.S. Forest Service, the U.S. Bureau of Mines studied the 17,000-acre Pyramid Peak planning area in order to evaluate its identified mineral resources. The planning area is located in Riverside County, CA, 15 miles south of Palm Springs. The planning area contains marginally economic resources of marble and mica, subeconomic resources of garnet and occurrences of gold and tungsten. The area is underlain by marble, quartzite, schist, migmatite, intrusive rock, and a wide zone of intensely sheared rock. Quaternary stream, landslide, talus, and colluvial material overlie the older rocks. Ten claims for marble in or overlapping the southwest and southeast parts of the planning area are current (1986). Many other current claims are outside the planning area, adjacent to or within 2 miles of the southwest and southeast corners. Hundreds of millions of tons of inferred, marginally economic marble in and near the planning area may be mined for cement or lime after other developed resources near markets are depleted or if large-scale construction or other markets develop nearby.

Jan 1, 1987

By Don M. Coulter

"INTRODUCTION Bauxite, in Appalachian Alabama, occurs in the Rock Run and Goshen Valley districts in Cherokee County; in Nences Creek Valley near Jacksonville; near Anniston in Calhoun County; north of Fort Payne in DeKalb County; near Ashville in St. Clair County; and near Talladega in Talladega County.In February 1942, Preston E. Cloud, Jr., assistant geologist, Federal Geological Survey, began a study of these bauxite deposits and the geology relating thereto.The Bureau of Mines established field headquarters at Piedmont, Calhoun County, in July 1942. Mineral agreements covering a total of 11,097 acres were executed with 15 landowners in the Rock Run district; 38 in the Goshen Valley district, covering 7,575.5 acres; and 3 in the Nances Creek Valley district, covering 988.5 acres. Drilling was done on the properties of 9 land¬owners in the Rock Run district, and on the property of 1 landowner each in the Goshen Valley and the Nances Creek districts. Drilling began October 26, 1942, and ceased on May 17, 1943.Power drilling was supplemented by a labor crew that drilled hand-auger holes in shallow deposits and sampled .old shafts, mines, and mine dumps.In all, 222 holes for a total of 13,250 feet were drilled. Of these holes, 88 penetrated bauxite but too low in grade to constitute ore."

Mar 1, 1948