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By J. A. Holmes, EDWARD C. FRANKLIN, RALPH A. GOULD

The commission may be permitted to express its earnest hope that the litigation which comes to an end with the findings and recom- mendations herein set forth will be considered by both parties to the action as definitely and equitably decided. The commission trusts that its work will show the value of the commission form of settlement and that its work will serve as a prece- dent to be followed in disputes relative to technical subjects. If the work of the commission is productive of a tendency on the part of technical litigants to avoid the use of the courts for the settlement of disputes it will not have been done in vain. Such tendency will surely grow and ultimately such differences will be arbitrated by technically trained men without recourse to the courts of law. Appended to the report of the findings of the commission are to be found the detailed reports covering the several lines of inquiry and investigation carried on by the commission and upon which its findings are based, and also a detailed statement of the fiscal affairs of the commission. A word of explanation is necessary in regard to the fiscal statement. While each party to the litigation has agreed to bear one-half of the expense of the investigations of the commission, it will be noted that the Selby Smelting & Lead Co. is credited with $21,000, while Solano County is credited with but $6,000. In order that the investigations of the commission might go forward without interruption the Selby Smelting & Lead Co. has generously supplied funds at the times they were needed. This assistance has been

Jan 1, 1915

By Henry M. Harris

Low-carbon shales from 65 deposits and 11 sources of coal-mine waste in western Oregon and Washington were tested in a rotary kiln for their suitability as raw material for expanded aggregate. Shales from 41 sources bloated enough to produce crushed, expanded aggregates, weighing less than 65 pounds per cubic foot in the preliminary tests. The samples were judged on the basis of processing qualities, physical properties, and size and uniformity of the source. Nine low-carbon shale deposits and three coal-mine waste sources were selected for more extensive bloating tests and for examination of the expanded aggregates in concrete shapes. Composite samples from these 12 sources and from 2 commercial operations, when processed for testing in concrete shapes, had bulk densities ranging from 37.S to 72.9 pounds per cubic foot. Damp-cured concrete shapes made with these aggregates had bulk densities ranging from S6 to 119 pounds per cubic foot, and all but three of the lightweight concretes had crushing strengths ranging from 3,270 to 6,810 p.s.i. Properties of the lightweight concretes were compared with those of concrete shapes made with commercial aggregates, and with sand and gravel.

Jan 1, 1962

By D. Pennington

Ground-water levels and subsidence have been monitored over a longwall panel of a deep coal mining operation located in western Pennsylvania. The monitoring network includes eleven ground-water monitoring wells completed to measure water level changes in separate shallow and deep aquifer zone-, and 50-foot surveyed subsidence stations parallel and perpendicular to the panel centerline. Monthly monitoring data were collected during the premining, mining, and postmining tine periods. Aquifer testing and borehole geophysical logging were conducted during premining, and post-mining conditions to document any changes in aquifer properties and ground-water flow patterns. Results indicate ground-water declines were located with respect to the mining face and mined longwall panel. Dewatering of the deep aquifer zone caused a significant water level decline in deep wells; however, the shallow aquifer zone was isolated fro major impacts by an aquitardal layer during, the, one-year period. Transmissivity data were greatly impacted by fracturing, in the highly anisotropic aquifer system. Borehole geophysical logging indicated changes in ground-water flow patterns and zones of increased fracturing from subsidence.

Jan 1, 1984

By Kenneth G. Skinner

Diatomite, also known as diatomaceous earth, diatomaceous silica, kieselguhr, and moler, has been used extensively for many years, but only during the past two decades has it become an important industrial mineral. United States sales for 1.936-38 totaled almost 280,010 tons,7 but relatively little (with the exception of that sold by an Oregon company affiliated with a larger California company) was sold by Pacific Northwest producers. In attempting to develop some of the many Pacific Northwest diatomite deposits, these producers have been handicapped by lack of published technical information regarding processing methods and the suitability of different deposits for specific uses. To determine some of the physical and chemical properties of known Pacific Northwest diatomites, the present investigation was started in 1938 by the Bureau of Mines in cooperation with the College of Mines, University of Washington. Figure 1 shows the location of deposits sampled. Because most relatively pure diatomites can be used as concrete admixtures or as inert fillers in rubber, paints, and plastics, this investigation concentrated upon determining some filter-aid characteristics and their relationship to other physical properties. A filter-aid is a powdered material that, when added to solutions to be filtered, improves flow rate, filtrate clarity, or both. Some chemical analyses also were made.

Jan 1, 1944

By C. H. Riggs

This report describes the geology and reviews the oil-production history of the Dutcher sands of Pennsylvania age in the Muskogee oilfield. The geology and production history are presented not alone as a review of the past behavior of the field but also to interpret the possibilities for future production of oil from semidepleted sands in this and similar areas. The Muskogee field, one of the oldest oil-producing areas in Oklahoma, yields paraffin-base oil of 40° API gravity -a gravity higher than that of most Oklahoma oils. Oil was discovered in the townsite of Muskogee in 1894 but was not produced in commercial quantities until 1904. A peak yearly rate of 1,340,000 barrels of oil was attained in 1910 (see table 1).

Jan 1, 1959

By Albert L. Toenges

EARLY in 1949, the Economic Cooperation Administration requested the Bureau of Mines to assign a coal-mining engineer to study milling conditions in Greek lignite mines; to make recommendations for the introduction of methods and practices that should increase production and decrease the cost of mining; and, from the results of a geological reconnaissance by geologists of the United States Geological Survey, to suggest plans for the development of mines to supply fuel for a thermal power plant, Albert L. Toenges was assigned to this investigation and arrived in Athens, Greece, March 15, 1949. The study of mining operations and the geological reconnaissance (which was made by W. G. Pierce and X. M. Denson, geologists, United States Geological Survey) Were conducted concurrently. The Geological Survey will publish the results of its investigation separately. Washability studies of lignites from Aliveri and Kimi were made at the Central Experiment Station of the Bureau of -Mines, Pittsburgh, Pa. The lignite fields mentioned in this bulletin are shown in figure 1.

Jan 1, 1951

By R. Karl Zipf, Francois E. Heuze

Stress analysis programs such as MULSIM/NL, LAMODEL, MinSim 2000, and EXAMINETAB are used in the mining industry to analyze stresses and displacements in coal mines, platinum mines, gold reefs, and tabular-type deposits. These relatively simple numerical models can efficiently simulate yielding and failure of a rock mass near a mine opening and subsequent stress transfer. The main input parameters for these models are a family of nonlinear stress-strain curves for the in-seam material. For many applications of these models, such as in coal mining, extensive field measurements and observations exist from which to estimate these stress-strain curves and calibrate the numerical models; however, such measurements are lacking for other types of mines. A three-step method is presented to determine nonlinear stress-strain curves for boundary-element (BE) programs used in many mining applications. The method requires a suite of laboratory-scale strength tests at various confining pressures. Note that this analysis uses laboratory-measured strength and modulus properties of alluvium. The dependency of the mechanical properties of alluvium on scale has not been established, although more tests are being planned. However, it is believed that the relative comparisons performed are valuable regardless of scale effects. First, the FLAC2D computer program is used to model the laboratory tests and determine cohesion (c) and friction angle () for a Mohr-Coulomb material model. Second, another FLAC2D model uses the c and values to calculate vertical stress and strain around a single opening in the rock mass. This model calculates the stress-strain path of points at various distances from the opening boundary. Finally, based on these stress-strain paths, the stress-strain curves needed for a BE analysis are derived. This three-step method was demonstrated in a large, flat-lying underground test facility in very weak rock. The BE analyses agreed well with observations of failure at the test facility and provided a basis for evaluating the behavior of alternative layouts.

By A. T. Iannacchione

The Bureau of Mines established geologic factors affecting the mining of the Lower Kittanning coalbed to aid in coalbed minability studies and examined the occurrence of "wants" (places where coal is missing) and types of unstable roof rock strata. Trends established from mapping, including prediction of areas of high methane emissions, were extrapolated to unmined areas. 'Wants' in the coalbed are of two types: Erosional and depositional. Erosional features occur where north-south-trending sand-filled channels cut into the coalbed. Variations in depositional environments have caused the coalbed to "split" into several thinner units. Slickensides, commonly indicative of unstable roof, are adjacent to and on the underside of sandstone channels; they were caused by differential compaction and by soft sediment sliding along the contact between the sandstone and adjacent shale. The frequency of unstable roof also increases where the interval between the Middle and Lower Kittanning coalbed is less than 30 feet. The zones of weakness at the contacts above and below the Middle Kittanning coalbed are the controlling factors for unstable roof in these strata. Methane emissions from the coalbed are controlled primarily by depth, fracture permeability, and rank of coal. Local geologic factors are coalbed thickness, associated rock strata, structure, and proximity to outcrop.

Jan 1, 1979

By G. W. Jones

[One of the mJor c~ctivities of the Bureau ~f l;ine;: is the j.a-onotion of sdetp in mining a.nJ other inclus tries. 13 cor'ncc tlcn td t~l tiiene activities the 3~.sccu r:e termine? t'le cwl.os:lon ha~arls 95 n,o;r.?xs tibla Tases, vzpor s, aid scli3s aqi iavestig~ ter rnrI.?ns of controlling s-~fi. prevpri ting eqlosians.]

Jan 1, 1941

By G. W. Jones

[One of the mJor c~ctivities of the Bureau ~f l;ine;: is the j.a-onotion of sdetp in mining a.nJ other inclus tries. 13 cor'ncc tlcn td t~l tiiene activities the 3~.sccu r:e termine? t'le cwl.os:lon ha~arls 95 n,o;r.?xs tibla Tases, vzpor s, aid scli3s aqi iavestig~ ter rnrI.?ns of controlling s-~fi. prevpri ting eqlosians.]

Jan 1, 1941

By Irving Hartmann

Falls of roof in coal mines and means of preventing them have been subjects of study for many years, and ran extensive literature has resulted, Usually each individual paper has placed 'emphasis on one phase of the subject, such as fatalities, nature and extent of nonfatal injuries, methods of tembering (particularly in rooms or other wide places), safety along retreating rib lines, and methods of causing falls in abandoned areas. It is only in recent years that there has been persistent question as to why

Jan 1, 1941

By Ben E. Lindsly

The recovery or partial recovery of the oil remaining in oil sands after the usual methods of production have become unprofitable is perhaps the greatest problem in the petroleum industry today. The amount of this oil remaining in the sand is variously estimated by those familiar with the subject to be 25 to 90 per cent of the original content.2 Lewis3 states, "The estimate of 80 to 90 per cent of the oil left underground does not seem incredible."

Jan 1, 1926

By Irving Hartmann

Falls of roof in coal mines and means of preventing them have been subjects of study for many years, and an extensive literature has resulted. Usually each individual paper has placed emphasis on one phase of the subject, such as fatalities, nature and extent of nonfatal injuries, methods of tembering (particularly in rooms or other wide places), safety along retreating rib lines, and methods of causing falls in abandoned areas. It is only in recent years that there has been persistent question as to why

Jan 1, 1941

By G. L. Oldright

"The various districts in the United States where complex lead-zinc ores occur are too well known to require description, there being hardly a mining State with any large amount of ores of either metal that is free from this problem. This paper briefly presents developments in the volatilization process, as applied to the treatment of such ores, since the data in Bureau of Mines Bulletin 211** were published. In that bulletin, among the many types of ore treated, examples are given of the treatment of lead-zinc ores by the chloride volatilization process for the separation of lead. An outline of the general process, with views of the rotary kiln, ore feeder, firing system (these three features resemble closely those of cement-kiln practice), dust chambers, and a Cottrell precipitator to remove the fume from the gas, are also shown in that bulletin, to which the reader is referred for the results obtained, and for practical details of operation. The small initial cost of a volatilization plant, and its adaptability for use in isolated districts were emphasized.In general, it was found that when an intensely oxidizing atmosphere was maintained in the furnace, a good lead-zinc separation could be made. Therefore, a heavy sulphide ore would have to be preroasted, and enough air would have to be admitted to obtain complete combustion of whatever fuel might be used.The work done by private companies and the bureau since the data for Bulletin 211 were obtained, indicates that the ores most immediately amenable to treatment by volatilization are of two types. The first is an oxidzed lead. silrer ore whose variable lime content makes it impractical to chloridize the ore for acidulated brine leaching, and whose base metal content makes treatment by cyanidattion unfeasible, The second type is the lead-zinc ore mentioned above, and is the one on which data are available for publication at present. This article Chows what ores of this latter type are amenable to treatment by volatilization, by giving briefly some of the more important physical and chemical properties an ore should preferably possess. Several examples are given from both laboratory experimental work, and from practice in the field, showing various phases of the volatilization process."

Nov 1, 1923

By S. E. Burton

The White Rock area of the Boiling Springs manganese-iron deposits comprises about 3,200 acres of land in Monroe Township, Cumberland County, Pa. (See fig. 1.) This property was brought to the: attention of the Bureau of Mines by Pennsylvania Geological Survey Bulletin 128, entitled "Manganese Ores of Pennsylvania" by R. M. Foose. It was examined by an engineer of the Bureau of Mines in August 1942 and was further investigated by the Bureau by churn drilling and underground development during the period December 1942 to February 1944. Beneficiation tests were made on samples of the ore. This report describes the work done during the investigation and presents the results obtained.

Jan 1, 1949

By Thomas Fraser

WHEN the Bureau of Mines initiated the program of large-scale research and development in the field of synthetic liquid fuels authorized in the Synthetic Liquid Fuels Act of April 5, 1044, the Coal Preparation Section was assigned the task of obtaining data on the preparation characteristics of the coal in large reserves that might be adaptable to use in this new industry. It is natural that, as the rapidly developing general research program brought about new concepts of raw-material quality, preferred geographical location, and the like, the orientation of coal-preparation investigations should have undergone some change. The first major assignment was the sampling and testing of a series of typical American coals deemed to he suitable for hydrogenation based on early research work conducted by the Bureau of Mines. This first series of tests has been completed and is reported in this paper.

Jan 1, 1950

By D. Bienstock

In connection with air-pollution studies, the Bureau of Mines is cooperating with the U.S. Public Health Service in investigating the use of solids for removing sulfur dioxide in concentrations of less than 0.5 percent from combustion and waste gases. Removal of sulfur dioxide at flue-gas tempera¬tures would no longer result in the cooling of scrubbed gas, which is inherent to liquid scrubbing processes used exclusively in industry today. Results are reported of extensive investigation, using metallic oxides as absorbents, adsorbents, and oxidation catalysts at 130° and 330° C. (temperatures at which flue gas may be treated in powerplant practice). The most active absorbents tested were the oxides of manganese, cobalt, copper, and alkalized alumina; 23 to 33 grams of sulfur dioxidn were removed by 100 grams of absorbent at 130° C., while scrubbing more than 90 percent of the sulfur dioxide from a simulated flue gas, and 19 to 61 grams of sulfur dioxide were removed at 330° C. A more detailed study is reported on absorption and regeneration, using manganese oxides and alkalized alumina. Adsorption of sulfur dioxide on activated carbons and molecular sieves at elevated temperatures is considerably less efficient than removal by absorption--a maximum of 7 to 8 grams of sulfur dioxide could be removed with 100 grams of adsorbent at 130° C. A potash-promoted vanadium pentoxide is effective in converting sulfur dioxide to trioxide; complete conversion in a simulated flue gas containing 0.35 percent sulfur dioxide was obtained at 365° C. Pilot-plant and cost studies are being made by the Bureau to determine the economic feasibility of removing on an industrial scale the sulfur dioxide present in gases in low concentrations.

Jan 1, 1961

By R. R. Sayers

The increasing use of hydrogen fluoride (annual consumption now exceeds 500,000 pounds (1)4/) directly and its occurrence as a byproduct of the utilization of fluorine compounds in the mineral industries, especially in metallurgical processes and in the refining of petroleum products, has aroused interest in its toxicity, and a brief review of the literature, with special reference to the hazard of poisoning in the mineral industries, seems to be opportune. Recently, residents in the vicinity of aluminum plants have been complaining of injury to livestock and vegetation as well as to their own health from the gases discharged into the air during operation of the plants, hydrofluoric acid gas apparently being the offender. The comparatively recent utilization of hydrofluoric acid in the alkylation process for the production of high-octane gasoline has raised the question of the hazard of poisoning in the petroleum Industry. In addition, the use of fluorine-containing refrigerants has extended the potential al exposure outside of industry (2).

Jan 1, 1945

Major producers posted 25¢-per-pound increases on cadmium, raising their domestic quotes to $2.75 per pound. COBALT: Cobalt consumption in February, exclusive of salts and driers, increased by 21 percent compared with consumption in January. Significant increases in consumption occurred in cutting and wear resistant materials, welding and alloy hard-facing rods and materials, magnetic alloys, and other alloys. The major sales agency for cobalt in New York reportedly announced price increases, effective April 15, 1976, for cobalt metal, powders, and oxide. The new price for 250 kilo (551 lb.) drums of cobalt metal (granules or electrolytic cathodes), f.o.b. Port of New York, was quoted at $4.40 per pound. This is the first cobalt price increase since January 23, 1975, and is the result of a price increase by Sozacom, the official Zairian sales agent. Other cobalt producers are expected to raise their prices in line with the new quote.

Jan 1, 1976

A maximum acceptable level of 2 mg/m3 of respirable coal mine dust in active mine workings was established, effective January 1, 1973, under the Federal Coal Mine Health and Safety Act of 1969. It is generally agreed that, as a result, coal mines in the United States are significantly less dusty than they were a decade ago. For example, operators of underground mining machines were exposed to between 3.9 and 6.5 mg/m3 of respirable coal mine dust during 1968-69; now they are exposed to between 1.3 and 1.8 mg/m3. Also, the incidence of underground sections cited for exceeding acceptable levels of respirable coal mine dust decreased during 1976-78, and the vast majority of all working sections are now in compliance. This improvement is very substantial by world standards. It must be regarded as a creditable accomplishment by the coal mine operators, federal agencies, and mine workers involved. Most of the improvement has been brought about by the use of existing technology to control, suppress, and collect respirable coal mine dust. Research and development by the Bureau of Mines has contributed significantly to the accomplishment by improving the methods for sampling, control, suppression, and collection.

Jan 1, 1980