Search Documents

By D. B. Dow

The study of oil production methods with reference to the amount of oil originally pressent in the oil-bearing, formations has developed the fact that-ordinary methods-of production remove only a part of the oil actually present. In fact, it is generally realized that when a field is abandoned more oil remains in the sand than has ever been removed. As a consequence of this realization, the petroleum engineer has devoted considerable tine in recent years in devising methods for increasing the percentage of recovery. His studies have indicated that in most cases the total production of a field is dependent upon the available gas rather than upon the available oil. Mien the gas in the sand is exhausted, oil production ceases even though there may be enormous quantities of oil remaining unrecovered. Consequently, any method of conserving the gas or increasing the supply of gas will increase the ultimate recovery from a field. The practice of producing oil under vacuum increases the effectiveness of the gas remaining in the sand, as well as furnishing more gas by evaporating the light fractions of the crude. Pumping ' compressed gas or air down selected wells of a lease has been found to increase the production of oil from the surrounding wells. Studies of oil and gas ratios have indicated that much of the available gas has been wasted as far as its effectiveness on oil production is concerned. his has led to the development of "stop cocking"3 and the practice of producing under back pressure3, which methods aim, to obtain more effective work from the gas with reference to the amount of oil delivered to the well.

Jan 1, 1926

By Walter E. Pittman

This Bureau of Mines study surveys the current state of technology and the various research efforts that have been undertaken to dewater the dilute phosphatic clays generated in the production of phosphate rock. The research described includes early dewatering experiments, fundamental studies of clays and of flocculation, and minor dewatering techniques such as freeze-thaw methods, the ANDCO process, moving screens, sand wick, crust development, and overburden pumping. Some methods that are currently being evaluated are described. They include the Estech sand-clay mix process using the Enviro-Clear thickener, sand-clay sandwiching, dredge mix, dredge process, and the sand-spray process. Developing technology for dewatering phosphatic clays also is described, including the Bureau of Mines rotary trommel method and the Gardinier process.

Jan 1, 1984

By Robert M. Becker

A multistage probability model for assessing the reliability of mineral samples following any number of stages of sample reduction is presented. Sample reduction is the process of alternately crushing or grinding and sampling mineral particles prior to assaying. The final multistage model developed accurately describes the ideal sample reduction practice. This model is based on previously developed and experimentally tested models for a single stage of sampling. The problem is approached through the probability distributions for the various stages of sampling. The probability distribution, moments, and moment relationships for a single stage of sampling are first reviewed, and the useful concept of unit moments is defined. In presenting the models for two stages of sampling, emphasis is placed on the physical description of the sample reduction process which leads quite naturally to its mathematical representation. In this representation, crushing or particle-size reduction between the stages of sampling is viewed as a random process with respect to the number and proportion of particles of the various kinds produced. The physical and mathematical description is extended to more than two stages of sample reduction, and the first three moments for any number of stages are developed. In common sample reduction practice the effects of a finite population (finite amount of material) at each stage of sampling appear to be important in describing the variance contribution of each stage. This is also true for the third moment about the mean. An example is cited in which the skewness increases by more than an order of magnitude when several stages of sampling are considered. This is largely due to the dependence of the multistage third moment about the mean on the variance. In general the model and results should be useful in helping to understand, control, and reduce the random errors that arise in the sample reduction process.

Jan 1, 1968

By Andrew B. Cecala

The Bureau of Mines conducted laboratory and in-mine tests on the Racal airstream helmet (Model #AR21) to evaluate its protection efficiency. Laboratory tests indicated that as ambient air velocity increased, the protection offered by the helmet decreased. In tests conducted at several coal mine long-wall sections with face velocities under 400 fpm, the helmet was 84 pct effective at reducing respirable dust in the miner's breathing zone. However, at a high-velocity section, 1,200 fpm, the efficiency of the helmet was significantly reduced, confirming our laboratory results.

Jan 1, 1981

By J. Roger Loebenstein

Small amounts of arsenic trioxide were shipped in 1988 from remaining stocks at ASARCO Incorporated's closed plant at Tacoma, WA. Imports of arsenic trioxide were at about the same level in 1988 as in the previous year. Legislation and Government Programs The Occupational Safety and Health Administration (OSHA) levied a $1.6 million fine against Asarco for exposing its workers at its East Helena lead smelter in Helena, MT, to unacceptably high levels of lead and arsenic. The bulk of the fine was for violations of a respiratory protection program. The same smelter and its environs has been listed as a Superfund toxic-waste site by the Environmental Protection Agency (EPA). Tests had shown high levels of lead, cadmium, and arsenic in the soil near the smelter. EPA planned to extend the cleanup to areas within the town of East Helena because high levels of arsenic had been found in shallow test wells outside the smelter site. Federal and State health officials have warned residents living in the vicinity of East Helena to avoid eating certain home-grown vegetables because of high concentrations of heavy metals.2

Jan 1, 1990

By P. D. Laverty

The U.S. Bureau of Mines treated mixed and contaminated super alloy scrap by pyrometallurgical and hydrometallurgical methods to separate and recover metal values. Best results were obtained by leaching Zn-treated or atomized scrap with HCI-02 at 9SO C and 50 psig 02' This resulted in dissolving approxi-mately 98 pet of the AI, Co, Cr, Cu, Fe, Mn, Ni, and Zn while rejecting over 98 pct of the Mo, Nb, Ta, Ti, W, and Zr as an insoluble refractory residue. Chlorine was successfully substituted for HCI to leach Zn-treated scrap but was unsuccessful for leaching atomized scrap. The leaching solution was treated by pH adjustment and hydrothermal precipitation at 2000 C for 4 h to remove AI, Cr, Fe, and other contaminants as a filterable precipitate. Recovery of Co and Ni would be accomplished by solvent extraction and e1ectrowinning. Chromium recovery as a ferroalloy was demonstrated.

Jan 1, 1989

By Oliver Bowles

"The manufacture of asbestos paper began commercially about 40 years age but its principal development has taken place during the past twenty-five years. The asbestos used by the ancients, termed amiantus by Pliny was used for winding sheets, tablecloths and other fabrics. It was probably chrysotile fiber and was a woven and not a felted product, and there¬fore is not to be confused with asbestos paper. There are, however, some early references to paper manufacture that are of interest. Pontoppidian, Bishop of Bergen, in his Natural History of Norway, published in 1750, refers to paper made from asbestos found in the parish of Waldens. He states that this paper did not burn when thrown in the fire, but the writing on it totally disappeared. This indicates that the primary ob¬ject was to obtain an indestructible writing paper. About 100 years later, further efforts were made with the same object in view. In 1853, a patent was issued for a process of making paper from a mixture of asbestos and alum. Many experiments were made to manufacture suitable asbestos printing paper. Some such papers contained only about one-third asbestos, the remainder being of combustible material. Such papers would burn, but would leave a white residue which retained its shape and preserved the written characters. On account of the difficulty of obtaining a smooth and even surface, and the tendency for the material to absorb ink like blotting paper, asbestos paper is not well adapted for writing or printing purposes. Other early uses of asbestos paper were for ornamental wall-paper and carpet linings. None of the uses mentioned above have developed to anything of importance in a practical way, but the manufacture of asbestos paper has become a very important industry, and it has found extensive uses in ways that were never dreamed of by the early investigators.It is recorded that the first sheet of asbestos paper made in America was manufactured in 1876 by John Roberts & Son Company, in a mill near Waltham, Mass. The material first used was a long-fibered amphibole asbestos from Italy. About three years later, Canadian fiber was introduced and proved to be very satisfactory. The shorter grades of fiber which would otherwise be wasted were used for the manufacture of paper and board. For several years, the product of this mill was sold through Rice Kendall of Boston, Mass. From 1881 to 1900, the H. W. Johns Company, of New York, took the entire product which was 30C to 700 tons per year. The latter company built their own asbestos paper mill at Brooklyn in 1900. Keasbey & Mattison Company, of Ambler, Pennsylvania, began to manufacture in 1897. Other early manufacturers were: the Asbestos Paper Company, at Baldwinsville, Mass„ and Mr. B. S. Binney, at Shirley, Mass. The number of manufacturers gradually increased until at present asbestos paper is manufactured by the following ten companies:"

Nov 1, 1919

By G. B. Shea

The accident experience of the California petroleum industry for 1927 was characterized by a decrease it .the number of fatalities. The year closed with a total of 41 fatal accidents, as compared with a total of 54 for the preceding year. 3 In percentage, the figure for 1927 represents a decrease of 24 per cent from that of 1926 and evidences the promising results of organized safety work, in which the industry in California has taken an absorbing interest. The percentage of decrease for 1927 is the largest recorded in any one year since the compilation of the fatality record in the California petroleum industry was begun. Although good progress has been made during the past few years, much remains to be done to reduce still further the human and economic waste caused by accidents. This review is intended to show the employee, as well as the employer, the proximate and contributing cause of accidents. To increase the value of the report, preventive measures in various instances are suggested, on the theory that accidents of a similar nature will occur unless remedial action in taken to remove the cause.

Jan 1, 1928

By H. Billmayer

This report covers the period from June 17, 1974 to February 20, 1975, and describes the work performed in compliance with the requirements of Contract No. H0346102 and Modification No. 1 thereto. The purpose of the contract was to design protective canopies for an Elkhorn Scoop, a Lee Norse Miner, a Wilcox Miner and a Wilcox Bolter; to construct mockups of the canopies; and to obtain machine operator evaluations of the canopy designs by assessing the mockups while installed on their machines in the mines. The overall program objective was to achieve protective canopy designs for the four machines which would be acceptable to the operators.

Jan 1, 1975

By John P. Powell, J. L. Eakin

"INTRODUCTION AND SUMMARYNowata County, in the northeast corner of Oklahoma, is one of the principal oil-producing counties of this stripper area. Many fields in the county were opened and much oil was produced before statehood. The location of the major fields, as defined by the Oklahoma Corporation Commission, 2/ the outline of the areas of water-flooding activity, and the location of the several projects described in detail in this report are shown in figure 1.There was some drilling in the county earlier; but it was not until after 1904, when the Secretary of the Interior confirmed as valid the leases granted by the Cherokee Nation, that the major drilling activity began. Initial development in this part of Oklahoma was in the Chelsea field in Rogers County, which adjoins Novata County on the south. The activity spread rapidly northward to the Alluwe and Coody's Bluff fields, and then to the Nowata-Claggett field. Continued exploration resulted in discovery of the Delaware-Childers field, where some wells having an initial production of 1,000 barrels daily were completed. Fields discovered and developed during the next few years included the Lenepah (Elliott), Adair, California Creek, Curl Creek, Woody, and South Coffeyville. The oil-production history of Nowata County is shown in figure 2. In assembling the data for a production curve, it was found that the combined production records for Nowata and Rogers Counties were available for 1914 to 1951, inclusive, and that records for the individual counties were available only from 1926 to 1951, inclusive. The early production figures for the counties from 1905 to 1914, inclusive, except for 1909, were calculated from the initial production statistics of the Federal Geological Survey mineral resources bulletins and production data assembled by C. H. Beal. 3/ The production values for 1905 to 1926 for Nowata County were obtained by dividing the total production for the two counties by a percentage factor derived from known facts regarding the oil industry in the area. Production figures for the individual counties from 1926 to 1933, inclusive, were obtained from the files of the Oil and Gas Journal, and the figures from 1933 through 1951 were obtained from monthly reports of the Oklahoma Corporation Commission."

Jun 1, 1952

Although the Stamler feeder/breaker has been used for coal crushing in underground mines for many years, it has only recently been applied to other crushing operations. Two companies presently using Stamler feeder/breakers for rock crushing were contacted regarding their experiences with the units in actual field use. In both cases information was obtained directly from the individuals responsible for field operation and maintenance of the units. White Pine Copper Co. has been using Stamler feeder/breakers for over two years to crush copper ore. They now have fourteen 450-ton-per-hour units on line. The ore has a compressive strength of from 18,000 to 28,000 psi and is extremely abrasive. Maintenance is performed on a tonnage basis. The breaker shaft is replaced every 250,000 tons (requiring about 4 hrs) and picks are replaced about every 1500 tons by the operator (requiring about 2 min per pick). Very little unscheduled maintenance has been required. Crushing costs are fairly high (estimated at 13 to 15t per ton including maintenance and operation) because of tale extreme abrasiveness of the material. A new Stamler feeder/breaker with Ultramet wear surfaces was put or line in June 1976. Ultramet was found to increase the life of belt transfer station surfaces by up to 400 percent and it is hoped that it will do the same for the feeder/breaker. At this time it is still too early to evaluate the performance of the Ultramet unit. If it does improve abrasion resistance, crushing costs could be greatly reduced. White Pine is very pleased with the units and the service provided by Stamler.

Jan 1, 1976

By Foster Fraas

In this Bureau of Mines report, use of the photoemission of electrons to produce electric charges for the electrostatic separation of sonic dispersed minerals, which had previously been ground to pass a 43µ-opening sieve, is demonstrated. It appears that many of the oxides, carbonates, sulfides, and arsenides will respond to photoemission. Minerals least responsive are the oxides of silicon, the oxides of aluminum, and minerals that have a high concentration of these oxides. Although several synthetic ore mixtures did not yield to complete separation in a one-stage operation, it is probable that preliminary neutralization of the initial electric charges produced by powder dispersion will provide complete separation. That the separation can be carried out in air and without the use of reagents or heating, which are required in the present practice of electrostatically separating coarse granular feeds, is of special significance.

Jan 1, 1972

By Dhaval Patel, Kim Witte, Charles Vaught, Michael T. Stephenson, Steve Booth-Butterfield, Cynthia Zuckerman, Brian L. Quick

This longitudinal field study was designed to encourage Appalachian coal miners in West Virginia and Pennsylvania to engage in hearing-protection behaviors. Method: Participants were mailed postcards that featured either a positive, negative, or neutral message on the outside of the postcard and a message encouraging hearing protection behaviors on the inside. The first posttest measurement of the effectiveness of the persuasive messages was conducted about a week after the postcards were mailed. The delayed posttest measurement was conducted six weeks later. Results: Responses from 307 coal miners revealed that the positive or neutral messages generated significantly more self-reported hearing protection behaviors than the negative message. Identical results were obtained in a delayed posttest assessment of miners' self-reported hearing protection behaviors. The positive message was also more effective than either the neutral or negative message in preventing defensive mechanisms from emerging over time. Impact on Industry: Positive and neutral messages were convincingly more than negative messages in facilitating self-reported hearing protection behaviors among coal miners. Similarly, the positive messages kept defensive processes at bay. Keywords: Hearing protection; Hearing loss; Coal miners; Campaign; Messages

By T. E. Gray

This report describes the preparation characteristics of the significant coalbeds in Boone County, W. Va., as determined by the Bureau of Mines. It is one of a series describing the coals suitable for producing metallurgical coke, either as mined or after beneficiation. Over 6.3 million tons of coal was produced in Boone County, W. Va., in 1959, of which almost 5.5 million tons was mechanically cleaned in eight preparation plants. On December 31, 1959, it was estimated that almost 8 billion tons of coal remained in the county in beds 24 inches or more in thickness. Thirteen samples were collected from nine coalbeds and washability tests were made on these samples.

Jan 1, 1961

Estimate costs for projected uranium in-situ mining operations. Approach Develop a computer model and an associated data base which will allow users to supply data applicable to a specific mining site in order to estimate total capital and operating costs for a potential in-situ mining operation at the site. How the Model Works The model requires a minimal amount of input from the user. The data input must be known or estimated information about a potential in-situ mining operation. The user can also supply any additional project specifications. The computer model uses a process-engineering approach and determines through a discounted cash flow analysis the total capital and operating costs for the life of the project. This time-span measures from the start of the pilot-scale operation through to the site's restoration and reclamation. The model will determine the production cost per pound of material mined subject to the rate of return identified by the user. Conversely, it will also solve for the rate of return realized for the specific sales price per pound. [ ] Currently the model's data base can tai ns costs, rates, and specifications for Texas and Wyoming, the only states where commercial uranium in-situ mining is being conducted. However, this model can be used by anyone who is conducting in-situ leaching or who plans to leach uranium in-situ. At least part of any uranium deposit has a potential for in-situ mining.

Jan 1, 1982

By David C. McHuron

The U. S. Bureau of Mines in their continuing research into sealants, selected MBAssociates to design, build, and test equipment and evaluate sealant as to its effectiveness is shale degradation. There were 20,050 sq.ft. of coal mine roof sprayed with a mine sealant and as a result, it has been estimated that the sealant coated roof has from 50% to 95% less roof falls than that roof which was not coated with sealant.

Jan 1, 1980

By Oliver Bowles

The term "stone" in its broader sense includes not only the well-known limestone, marble, granite, sandstone, and slate but also precious and semi precious stones and many minerals and rocks not included in the principal groups. Stones have long been used for structural and ornamental purposes. To be so used, they must be cut to various shapes and sizes, and some must be polished to bring out their inherent attractiveness.

Jan 1, 1958

By A. J. Farstad, R. F. Kehrman

Characteristics of metal/non metal mines were evaluated to determine the suitability of applying the U.S. Bureau of Mines electromagnetic location system to the problem of locating trapped driers in metal/non metal mines. Statistical distributions of mine depths and overburden conductivities show that the existing USBM EM system is inadequate for most metal/non metal mines. Alternate approaches to trapped miner location in deep mines were identified and subsequent field tests were conducted at six (6) mines to evaluate their feasibility. The approach considered to be the most promising is one which utilizes the existing manpack transmitting system, modified slightly for a dual frequency output, in conjunction with a sophisticated signal processing receiver on the surface. The main advantage of staying with a "through the earth" approach is that the underground equipment can be kept simple, easily maintained, light- weight and inexpensive.

Jan 1, 1979

By Jack C. White

As part of an investigation of the production of alumina by the nitric acid leaching of kaolinitic clay, the Bureau of Mines designed, built, and tested a fluidized-bed system for the calcination of aluminum nitrate nonahydrate to alumina, while recovering nitric acid. The calciner consisted of an 8-in-square by 36-in-tall vessel containing 18 in of fluidized solids. Molten aluminum nitrate, sprayed directly into the fluidized solids, formed sandy, granular alumina by growth of successive layers on fluidized particles. Solids were fluidized in a dense bed at temperatures of 250° to 500° C with steam, air, or mixtures thereof. Decomposition of nitrate ranged from 4 to 10 pet during single-pass steam or air fluidization, respectively. Alumina dust losses and low throughput are significant unsolved problem areas.

Jan 1, 1982

By Howard C. Turnage, Dana T. Updyke, Wayne C. Muhler

The objective of this project was to develop technical data and evaluate performance and utility of leaky feeder communications systems currently used in North American underground mines. The desired information was obtained principally through on-site surveys. Altogether, six of the seven mining companies known to be using leaky feeder communications were visited. This report covers the findings of these surveys. In addition, the report provides a brief background summary of mine communications, a technical discussion of leaky feeder systems, and conclusions and recommendations based on the results of the survey.

Jan 6, 1980