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By R. B. Ladoo

"Present Situation:At the beginning of 1920 a general feeling of optimism was noted in many talc-producing districts. The industry seems to have recovered from the temporary depression of the first half of 1919 and many mills are running at capacity production with their entire output for 1920 contracted for. The imports of talc for 1919 were only slightly larger than in 1918 by weight and probably no more by value. Thus foreign competition has not begun to be seriously felt. Several new companies in this country have been organized, some to operate new deposits and others to continue the work done by others.An interesting phase of the present situation is the possibility of increased use of talc in paint. There is a shortage of barium sulfate used as a paint filler. Since, for some uses, talc is considered second only to BaSo4 as a filler for paint, it is possible that part of the shortage could be relieved by an increased use of talc.A series of physical tests upon all pigment materials used in the manufacture of paints is being conducted for the Paint Manufacturers Association of the United States. It is important that all types of talc be represented in these tests. Producers of finely ground talc, 200 mesh and finer, are urged to submit samples of at least two pounds each of these grades that are available to paint makers with trade name and quality data, to the Institute of Industrial Research, 19th & B Streets, N. W., Washington, D. C., where the tests are being conducted."

Jan 1, 1920

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 McHenry Mosier

The Bell mine operated by the Warner Co. at Bellefonte, Pa., has an annual production of about 600,000 short tons of high-grade limestone. Since 1924, shrinkage stoping has been the mining method. Horizontal, long-hole diamond-drilling for production in stopes was started with one machine in July 1946. It is now standard practice. The burden on the holes is 10 feet. Diamond bits are noncoring EX-size in both concave and pilot types. The two types have little difference in drilling speed at the Bell mine. The diamond drills are mounted on 3-inch single-screw columns. Diamond drilling shows a marked increase in efficiency at the Bell mine, compared to percussion drilling, with respect to tons broken per drill shift, tons broken per foot of hole, and tons broken per pound of explosive. The advantages of diamond-drilling blast-holes also include (a) improved safety, greater footage per drill shift, (c) better frag- mentation of the broken, stone, and (d) reduction in amount of barring down required in stopes because the working places are limited to slots which have a relatively small area.

Feb 1, 1948

As a part of its overall wealth in fuel resources, the United States possesses large reserves of coal of ignite rank. According to recent estimates of the Federal Geological Survey (3, 5),l/ the assured lignite reserves of this country amount in total to over 463 billion tons, equivalent to 24 percent of our total national coal reserve on a tonnage basis and 15 percent on a heating-value basis. Distribution and relative amounts of United States coal and lignite reserves are indicated in figure 1. By far the largest proportion of our lignite reserves, over 95 percent is found in North Central States, principally in North Dakota, South Dakota, and Montana, in the vast coal-bearing structural grouping designated as the Fort Union formation. Of the remaining United States reserves, all but a fraction of 1 percent are found in a series of relatively scattered deposits in Texas.

Jan 1, 1954

By Grant Buma

Groundwater restoration is an uranium leaching. Information on the technology, costs, and the current permitting regulations is of vital operators and to firms considering in important aspect of in situ effectiveness of the current state and federal government importance to in situ leach situ leaching. This study, funded by the U. S. Bureau of Mines, describes: (1) all recent restoration attempts at commercial in situ leach operations, (2) restoration costs reported by the industry, (3) empirical equations that predict the amount of groundwater flushing required to meet the current restoration criteria, and (4) in situ uranium permit requirements for the states of Texas, Wyoming, New Mexico, Utah, Montana, Colorado and South Dakota, and Federal requirements.

Jan 1, 1981

By C. H. Riggs

THIS REPORT give's the results of a study of the central and south parts of the Cushing oilfield, including a description of the geology, a review of the production history, and estimates of oil reserves available by secondary-recovery methods. Each of the major producing zones of the field is treated separately. The report, which is one of a long series of field studies the Bureau of Mines has conducted over the past 40 years, was prepared to aid operators to increase oil recovery and to help prevent underground waste in the Cushing field, in the State of Oklahoma, and in the United States. The geology and production history are presented not as a review of past behavior of the Cushing field but rather to interpret the possibilities for increased oil recovery by future development of this and similar areas. The field, which is in the northwest corner of Creek County, Okla., was discovered in 1912 and developed during 1913 and 1914. For several years it, was one of the most important areas producing high-grade crude oil in Oklahoma. Although some oil has been recovered from each of 10 separate reservoirs, nearly 98 percent of the total recovery of oil in the area studied was from 4 major producing formations (table 1). Of these, only the Bartlesville [ ]

Jan 1, 1958

The research described in this report was conducted under a cooperative research agreement between the U.S Bureau of Mines Twin Cities Research Center (TCRC), Cleveland-Cliffs Inc. (CCI), and three operations in Northern Michigan managed by CCI: the Empire and Tilden surface taconite mining operations, and the Central Shops maintenance facility. All of these operations are in or near Ishpeming, MI. The Human Factors Research Group at TCRC is responsible for designing, planning, and conducting the research, and reporting on the findings. This project was carried out in order to investigate the high prevalence of back injuries being experienced by workers employed at the three CCI Northern Michigan sites, In an analysis of Company accident records for workers employed at these sites, it was determined that back injury problems confronting the CCI sites mirror those confronting the entire mining industry.

Jan 1, 1994

Endless lines at service station gasoline pumps, limited travel at reduced speeds, thermostats set at an uncozy sixty-eight degrees in the dead of winter-these are but a few of the inconveniences and discomforts that awakened Americans to a realization that our domestic minerals resources, traditionally taken for granted, are not boundless. We begin to accept and practice principles of conservation, yet we are aware that this alone cannot appreciably forestall the inevitable depletion of our minerals, metals, and fossil fuels-resources critical to our Nation's economy. The key to warding off shortages is the development of technology that will insure a continuing, adequate supply of minerals and energy from reliable sources at the lowest possible costs to society and the environment. The mission of the Bureau of Mines is to develop this improved technology. Established in 1910, the Bureau of Mines of the Department of the Interior is the Federal Government's primary research arm in the minerals and fossil fuels fields. In addition to its research role, the Bureau keeps the Government informed of the Nation's mineral posture. The Bureau also seeks to stimulate private industry, through the awarding of grants and contracts, to produce minerals and fuels at a rate compatible with the country's increasing demands.

Jan 1, 1974

By K. B. Bengtson

This task report provides the process technology, preliminary design, capital and operating costs for a 25 TPD pilot plant to produce cell-grade alumina using a clay/hydrochloric acid extraction - HCI gas induced crystallization process. The report consists of six volumes: I - Process Technology and Costs; II and III - Equipment Lists, Specifications and Quotations; IV and V - General Specifications; VI - Drawings. The process was selected by the Bureau of Mines as the more promising method to produce cell-grade alumina from clay based on the results of the two previous task reports under this contract: Task I - Comparison of Six Processes (alunite, anorthosite-lime sinter, clay/sulfurous acid, clay/nitric acid, clay/hydrochloric acid evaporative and gas-induced crystallization) and Task 2 - Comparison of Two Processes (clay/nitric acid and clay/hydrochloric acid - gas induced (crystallization). The pilot plant process utilizes a unique dual crystallization process to produce aluminum-chloride-hexahydrate crystals having sufficient purity when decomposed to meet stringent alumina product specifications. The size of the 25 TPD pilot plant has been selected to permit scale-up to commercial size plants of equipment, technical and economic parameters. The capital cost estimate for the pilot plant, exclusive of fee and escalation, for a southeastern U.S. location is $52,311,000 expressed in 1979 dollars. The total time required to construct the pilot plant including engineering and procurement is 32 months. The operating cost to produce the estimated 9,000 tons of alumina required for testing in Hall cells is $40,91[0],190 expressed in 1979 dollars.

Jan 1, 1979

The mineral Industry, following the economy as a whole, experienced little growth in 1992. However, with modernized plants, efficient workforces, and lower operating costs, the industry is well positioned to take advantage of possible improvement in the national economy during 1993. In addition to the significant 1992 events highlighted below, important events, trends, and issues within individual mineral industries are addressed in the commodity sections that follow. The value of processed materials of mineral origin is estimated to have been about $310 billion in 1992. The value of U.S. raw nonfuel minerals production in 1992 is estimated at approximately $32 billion, a 3% increase over 1991. The value of domestic minerals production has increased in all but 4 of the last 32 years.

Jan 1, 1993

By David A. Summers

Coal is increasingly viewed as one of the major fuel resources of this country for the remainder of this century. The need to extract a greater percentage of the coal in a given seam, together with advantages of improved safety, indicates that longwall mining will become more widely used within this time frame. A novel method of mining coal on a longwall face, utilizing high pressure water jets, is herein described. The mining machine proposed will exploit the stress conditions which exist on a longwall panel in order to achieve the required productivity while at the same time reducing respirable dust and methane ignition hazards. The water jets will excavate only the boundary of the extracted seam section, and thus the energy requirement of the machine will be minimized. The action of the machine is similar to that of an existing coal plow, except in that the wedge teeth of the plow are replaced by oscillating high pressure water jets. The machine can, therefore, cut to the depth and at the speed of existing shearer units at equivalent power levels. The removal of impact stresses from the machine will reduce downtime required for maintenance and replacement of picks and lower the load on the haulage motor of the system. The ability of the machine to increase the depth of cut without an increase in horsepower will further improve productivity when transportation systems to remove the greater production are in operation.

Jan 1, 1974

By Charles J. Haas

The objective of this research was to investigate the interaction phenomena of rock and types of rock bolts to develop design principals for using grouted roof bolts. The investigation was to determine the effectiveness of grouted bolts in resisting lateral displacement and axial separation along fracture planes, and also to determine if grouted bolts eliminate the axial tensile stress near the anchor and the resulting rock fracture. The first year's effort involved defining the post-tensioning response of grouted bars and determining the amount of shear resistance generated by conventional and resin-grouted bolts. A finite-element analysis showed that if the rock and resin grout behave in an elastic manner, the post tensioning of a grouted bar will affect mine roof stability only if movement occurs near the collar. An experimental shear test program revealed that both conventional bolts and resin-grouted reinforcing bars significantly increase shear resistance along fracture or bedding plane when the average normal compressive stress on that plane is low (in the order of 25 psi) and when the bolt is oriented so that the shear displacement tends to lengthen the bolt. An increase in shear resistance is also noted at the higher normal pressure of 250 psi; however, the increase is small compared to the corresponding shear resistance without a bolt. Conventional bolts oriented so that they tended to loosen with shear displacement added no significant shear resistance.

Jan 1, 1974

By Arthur C. McFarlan

There are two distinct coal fields in Kentucky-the Eastern field constituting a part of the Appalachian coal region and the Western field constituting the southern part of the Eastern Interior region. The outcrop pattern of the State is dominated by the Cincinnati arch. Coal-bearing Pennsylvanian strata occupy a low structural position on either flank, preserved thereby from erosion, which in the past has removed these same beds, though a much thinner succession, from the crest of the arch. General geological relationships are shown in figures 1 and 2. On April 13, 1750, Dr. Thomas Walker discovered the first coal recorded in Kentucky. He entered the State through Cumberland Gap (Cave Gap) and found coal a few miles north.

Jan 1, 1944

By M. H. Stanczyk

Bench-scale laboratory tests were made by the Bureau of Mines of a segregation-flotation concentrate, assaying 20.43 percent copper, to investigate the influence of various ratios and concentrations of ammonia and carbon dioxide on copper extraction. Leaching the concentrate with a solution containing 900 pounds of ammonia and 360 pounds of carbon dioxide per ton of feed, followed by washing the leach residue with 1.75 tons of a 10-percent solution of ammonium carbonate and about 1 ton of water (as steam) per ton of solids, resulted in a copper recovery of 96.3 percent. Resegregation and flotation tests of the washed residues revealed that 85 percent of the copper in the residue could be recovered. Steam distillation tests of a typical ammoniacal leach liquor, assaying 39 grams copper, 105 grams ammonia, and 77 grams carbon dioxide per liter, recovered over 99 percent of the copper as a mixed oxide-carbonate precipitate. The ammonia losses in leaching, filtering, washing, and distillation were 0.12 pound per pound of copper recovered in the precipitate. Calcination and subsequent hydrogen reduction of the precipitate yielded a metallic copper powder assaying 98 percent Cu, 0.87 percent Si02, 0.10 percent MgO, 0.54 percent CaO, and 0.41 percent R203.

Jan 1, 1961

By J. B. Zadra

During the investigations of the occurrence of manganese in the western United States, the Bureau of Mines received a 100-pound sample of manganese ore from the Doyle-Smith property, Yuma County, Ariz. Laboratory tests were made to determine the amenability of this ore to standard ore-dressing methods of concentration to produce a marketable-grade product. The Doyle-Smith claims are in northern Yuma County, within 15 miles of the Artillery Peak deposit. The lot of ore used in the test work was taken from the outcrop of a large, massive, irregular bed of oxide manganese ore found on the claims.

Jan 1, 1952

By A. C. Johnson

The Ellington manganese deposit in Reynolds County J Mo., had been known for some time; and limited exploration, consisting of test pitting and sinking a shaft 54 feet deep on the property, had been done by private interests. Late in 1941, the Bureau of Mines cleaned, deepened, and sampled many of the existing pits and dug and sampled 27 new ones. The shaft was unwatered and sampled, and several pockets of manganese ore were trenched to determine their extent. Samples were analyzed and beneficiation tests on 1 ton of the ore were made at the Rolla, Mo., station of the Bureau of 'Mines. Results of the investigation indicated that the deposit was small and low in manganese content.

Jan 1, 1948

By Kyei-Sing Kwong

The U.S. Bureau of Mines investigated the synthesis of advanced ceramics (SiC+AlN, SiAlON, SiC+A1203, and Si3N4+AlN) from natural clays (kaolin, halloysite, or montmorillonite) by an intercalation and heat treatment method. This process includes the steps of refining a clay, intercalating organic chemicals into its layered structure, drying the intercalated mixture, firing the treated structure at certain temperature ranges in controlled atmospheres to form desired compounds, and grinding the loosely agglomerated structure. Focus of this research is to economically process advanced ceramic structures from abundant natural resources. The advanced ceramic phases produced in this simple treatment are homogeneously distributed at the nanostructure level, and may potentially lead to cost effective manufacturing processes. The intercalation of clay was confirmed by X-ray and BET analyses. The evolution of chemical compositions during carbonization reactions and carbothermal reduction was investigated. The characteristics of refined clays and synthesized powders were studied. Advanced ceramic composites/solid solution have been produced from intercalated clays, without the presence of other compounds.

Jan 1, 2010

By Thomas E. Green

A gas volumetric method was developed for determining metallic aluminum at the 0.01-to 0.3-percent level in 100-gram samples of recycled glass. The method is based on the measurement of the change in gas volume produced by the reaction 2 Al + 2 NaOH + 2 H2O ? 2 NaAl02 + 3 H2 using a simple apparatus assembled from readily available glassware. Apart from sampling errors, the precision of the method is within ±5 percent. A minor modification of the apparatus would extend the method to larger samples or samples of higher metallic aluminum content. Metallic iron and metallic zinc do not interfere at the concentrations found in recycled glass recovered from incinerator residues.

Jan 1, 1971

By Dorsey A. Lyon

"The ceramic industry of the United States has a total yearly manufactured product of nearly half a billion dollars, despite large foreign importation.After careful investigation of the industry by the Bureau of Mines, it is the belief of those in charge that the usefulness of the industry can be greatly enlarged and the importations greatly lessened through the development of processes that will lead to a greater and better development of the ceramic resources of the United States. This will result in a greater industry with more men employed than ever before, and perhaps a world's supremacy in ceramic trade matters.Investigations in behalf of the ceramic industry are being made at the Bureau of Mines experiment ceramic station at Columbus, Ohio, under the supervision of R. T. Stall, superintendent, who reports a number of instances of practical, beneficial cooperation between the industry and the station during the last fiscal year.Graphite to Crucibles:Prior to 1914, practically all graphite crucibles manufactured in the United States were made from Ceylon graphite bonded with German Klingenberg clay. It was the general belief among graphite crucible manufacturers and users that good crucibles could not be made from American bond clays and graphites.Graphite crucibles were essential for melting certain alloys and special steels urgently needed for the manufacture of war materials. The demand for such metals was so great that it created an unprecedented demand for graphite crucibles.After the European war began no Klingenberg clay could be shipped out of Germany. However, it was fortunate for the cyucibly makers that they had large stocks of Klingenberg clay on hand. When the stock of Klingenberg clay became exhausted, it was necessary for the credible makers to turn their attention to American clays. There were no data or other information available to guide the crucible makers in the selection of good bond clays for their crucibles. It was necessary for them to select their clays more or less by ""guess"", which resulted in the period of service or life of graphite crucibles being shortened 15 to as much as 60 per cent."

Feb 1, 1921

By L. F. Willmott

Pulverized high-volatile A bituminous coal was gasified with oxygen and superheated steam in a pressure-gasification pilot plant equipped for slurry feeding. The minimum ratio of water to pulverized coal that could be pumped satisfactorily as a slurry was about 1 to 1. Heating this slurry produced a suspension of coal in superheated steam having a steam-to-coal ratio greater than the 0.3 to 1 proportion that is considered optimum for pressure gasification of pulverized coal. A steam separator removed enough steam to provide ratios down to about 0.5 to 1, but a 0.3 to 1 ratio was not achieved. Gasification of Sewickley coal produced a synthesis gas containing about 36 percent H2, 46 percent CO, and 13 percent CO2, Gas output, gas composition, and coal and oxygen requirements were Virtually the same as for a pilot plant equipped for fluidized-coal feeding. Typical results from the slurry-fed plant at 300 psig were carbon gasified, 95 percent; coal requirement, 34 lb/M (thousand) std cu ft CO + H2 produced; oxygen requirement, 365 std cu ft/M std cu ft CO + H2 produced. The results showed that the two feeding methods are equally satisfactory from the standpoint of gasification. A choice between a fluidized-coal gasification process or a slurry gasification process depends on considerations relating to the coal-feeding phase itself, including capital and operating costs, manpower requirements, safety, and flexibility of operation.

Jan 1, 1962