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By V. F. Parry, John P. Goodman

"INTRODUCTION Review of Previous Work Many investigators and certain commercial interests have recognized that the briquetting process is a practical method to convert much of what is now considered undesirable fuel into a usable form of domestic fuel.The art of improving the form of solid fuels is ancient, as early records indicate that the Chinese employed crude hand briquetting of combustible materials long before coal was known in Europe and America.According to Franke, 4/ the earliest description of a briquetting proce¬dure employed in the Occident is contained in an English patent dated in 1773. Following this in rapid sequence, many methods and procedures wore developed in this country and in Europe. Stillman/ states that the first attempt to briquet coal in the United States was made by Loiseau 6/ at Fort Richmond Piers, Philadelphia, in 1872. The American briquetting processes outlined by Stillman comprise an imposing compilation of successes and partial and outright failures."

Jun 1, 1943

By Nicholas P. Callas

This report presents research results obtained in the investigation of deviation control of boreholes in the rotary drilling process. The approach taken in this research is the passive method of placing stabilizers in the bottom-hole assembly to control deviation. Extensive use was made of the drill string mechanics theories of Lubinski and Woods. Analog, digital and hybrid solutions to variety of boundary value problems were investigated in order to determine the best models for bottom-hole assemblies. Field drilling data was analyzed and the results obtained from various models were compared to the actual drilling results. Various accomplishments of this work have been published in open energy industry literature, with more publications to follow.

Jan 1, 1981

By E. C. Yeager, E. O. Wagner, A. W. Koth, V. F. Parry, J. B. Goodman, D. G. Gernes, W. L. Patty

"In July 1943, the Bureau of Nines received an appropriation to investigate the beneficiation of Minnesota iron ores through the use of lignite. The broad objective was to find a way to link the large deposits of lignite in North Dakota with the low-grade iron ores of Minnesota. It was proposed that sponge iron might be made through new methods of processing, and one of the objectives was to determine the possibilities of gaseous reduction of fine ore. The problem of obtaining high-hydrogen reducing gases from lignite was assigned to the Subbituminous Coal and Lignite Section of the Bureau of Mines in August 1943.Through the advice of technical consultants and men familiar with the mineral resources of Minnesota and North Dakota, a tentative program of development was outlined. The first proposal was to study the gasification of lignite briquets in a standard water-gas machine. Previous experience with gasification of lignite indicated that the raw fuel would not be suitable for use in the conventional water-gas process on account of degradation, but gasification of lignite briquets appeared possible. Through the cooperation of the Northern State Power Co„ a series of tests was made at the company's plant in Grand Forks, N. Dak., on lignite-char briquets made by the Lehigh Briquetting Co. at Dickinson, Dak. These briquets are made by the Lurgi process, and they have been used satisfactorily as a domestic fuel. The object of the tests was to compare gasification properties of lignite-char briquets with those of gas. coke made from Kentucky coal, normally used in the Grand Forks plant. The tests revealed that the lignite-char briquets were not suitable for gasification, in the standard water-gas process because of disinte-gration and low efficiency caused by loss of fine carbon.While these investigations were underway, a joint Minnesota-North Dakota Development Commission was formed to aid in planning investigations on development of mineral resources of the two States. Some members of this commission were technical men, who with consulting engineers on the Bureau's staff made up an unofficial technical committee, and assisted in solving certain problems connected with gasification of lignite and beneficiation of iron ores. This committee has been of 'real assistance in guiding the investigation.A technical meeting was held in Minneapolis on November 10 and 11, 1943, for further discussion of objectives and certain technical problems. Results of tests on lignite briquets were presented, and several reports analyzing other methods of gasification were discussed. The Reyerson-Gernes process for the continuous gasification of lignite in an externally heated retort was considered from several angles. This process differs from others in that the natural moisture in the coal is utilized to help gasify the coal, and the volatile matter is largely decomposed. Although this process had been carried out successfully in a small steel retort, no definite design for a commercial-scale retort had .been developed. It was first proposed that the process might be carried out in a Glover-West retort. However, it was brought out that a Glover-West retort would require modification to simulate the process correctly, and that good results might not be obtained even then owing to the leakage of gas through the refractory walls and to an anticipated low rate of heat transfer at the gasification temperature suitable for lignite. Further, the probable leakage of inert furnace gas into the water-gas would be adverse to the Objective to obtain a gas that could be purified to 96 percent hydrogen."

Jun 1, 1946

By H. W. Gillett, E. L. Mack

Prior to 1911 the literature on melting brass by electricity consisted entirely-save for some suggestions made in patent literature but not actually worked out-of a few observations by farseeing men ' on the theoretical advantages of melting brass and other nonferrous alloys in electric furnaces. Roeber was the first to see and clearly state the possible advantages of the electric furnace in brass melting. The same factors tha.t make it desirable to manufacture special steels in the electric furnace rather than in crucibles, he declared, apply to brass as well. He pointed out the possibility of using larger melting units, of eliminating crucible cost, of readily controlling the purity of the product. and of nearly eliminating the loss of zinc. "The replacement of the • old crucible process is sure to come," he said; "perhaps it will come in two years, but it will, necessarily, in ten years .... The inevitable advance along this industrial line will have great influence in the metal world and will also provide, in large cities, a new kind of load for the central station." The years 1905 to 1910 may be termed the purely theoretical period of the development of the electric brass furnace, though the Conley furnace was tried out e:xperimenta.lly about 1910 and a few heats were made in an induction furnace. 2 In December, 1911, the American Chemical Society held a symposium on mineral wastes, at which Bassett s discussed the zinc· losses that attend making brass in fuel-fired furnaces.

Jan 1, 1922

By W. W. Adams

Every man-hour of work performed in and about the coal mines of the United States had a 2-percent heavier death load from accidents in 1938 than in 1937. This is an unorthodox way of stating that the death rate per million man-hours of exposure or employment was 2 percent higher in 1938 than in 1937, increasing from 1.74 to 1.78. Thus the average miner had a 2-percent greater chance of being killed in 1938 than he had in 1937. The average quantity of coal resulting from 1 man-hour of work increased 3.6 percent -from 0.615 ton in 1937 to 0.637 ton in 1938. The production of the average ton of coal was accompanied by a slightly smaller loss of life in 1938 than in 1937, the accident rate being 2.793 per million tons in 1938 compared with 2.833 in 1937.

Jan 1, 1941

This report presents the results of a study for the Bureau of Mines to compare loan terms for non-fuel mineral projects in developing countries, from various International Financial Institutions (IFIs), and from private sector commercial sources. The study compares IFI and commercial loan terms for seven mineral projects in developing countries. The International Financial Institutions represented are: ? International Bank for Reconstruction and Development (World Bank) ? International Finance Corporation (IFC) ? Inter-American Development Bank (IDB) ? Asian Development Bank (ADB) ? International Monetary Fund (IMF) In addition, the costs of financing for these mineral projects were compared with the costs of long-term debt to the five largest U.S. mineral producers.

Jan 1, 1986

By Ronald S. Conti

A new U.S. Bureau of Mines 6.8-L ignitability furnace was used to study the thermal autoignitability of dust clouds. This furnace has a quartz window to allow observation of the early stages of the ignition process and to allow measurement of the dust explosion temperature. Thermal ignitability data were obtained for various carbonaceous and metal dust clouds, with particular emphasis on various ranks of coal dusts. One of the reasons for the construction of the new 6.8-L furnace was to evaluate the effect of chamber volume on the measured autoignition temperatures. Therefore, data from the 6.8-L furnace were compared with data measured earlier in a 1.2-L furnace. The conclusion is that the autoignition temperatures measured in the 6.8-L furnace were only slightly lower on average than those from the 1.2-L furnace. These data on the minimum autoignition temperatures of various materials will be useful in analyzing the thermal ignition hazards of dust clouds in the mining industry and other industries that manufacture, process, or use combustible dusts.

Jan 1, 2010

By W. W. Adams

The accident-prevention record of the coal-mining industry in the United States was more favorable in 1936 than in 1935, both from the standpoint of the relative safety of the individual miner on the job and of the price in life and limb that the Nation paid for its year's supply of coal. The increase in relative safety of the individual miner was indicated by a lower death rate and a lower injury rate than in the preceding year per million man-hours of exposure to the hazards of mining; that is, per million hours of work performed by the employees. (See table 1.) A reduction in the price in life and limb that the Nation paid for a year's supply of coal was indicated by a smaller death rate and a smaller injury rate per million tons of coal produced. Thus the individual miner was a better insurance risk, as far as accidents were concerned, in 1936 than in 1935, and a ton of coal used in the homes and industries of the country represented less human suffering than in 1935. The two points of view are distinct, and both should be kept in mind when considering accidents and safety in coal mining or in other industries. More men were employed in 1936 than in 1935, and more workdays were available for the individual miner. Large gains were also made in the total number of man-shifts and man-hours worked in the industry as a whole. In number of tons of coal mined, 1936 showed large gains over 1935. Moreover, the average output of coal per man-hour worked was higher in 1936 than in 1935. All of these gains were made without lengthening the average number of hours of work per man per day.

Jan 1, 1939

By Branch of Editorial Services

"The Bureau of Mines was established in the public interest to conduct inquiries and scientific and technologic investigations concerning mining and the preparation, treatment, and utilization of mineral substances; to promote health and safety in the mineral industries; to conserve material resources and prevent their waste; to further economic development; to increase efficiency in the mining, metallurgical, quarrying, and other mineral industries; and to inquire into the economic conditions affecting those industries. The organic act of the Bureau, as amended by Congress and approved February 25, 1913, made it the province and duty of the Bureau of Mines to ""disseminate information concerning these subjects in such manner as will best carry out the purposes of this Act.""In accordance with this directive, the Bureau reports the findings of its research and investigations in its own series of publications and also in articles that appear in scientific, technical, and trade journals; in proceedings of conventions and seminars; in reference books; and in other non-Bureau publications. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make the kind of list and index presented in this special publication both necessary and valuable. This issue of the Bureau of Mines List of Publications and Articles describes reports and articles published during the period January 1, 1980, to December 31, 1984. It supplements the 50-year list of Bureau publications issued from July 1, 1910, to January 1, 1960;1 the 50-year list of articles by Bureau authors published outside the Bureau from July 1, 1910, to January 1, 1960;2 the 5-year lists of publications and articles from January 1, 1960, to December 31, 1964,3 from January 1, 1965, to December 31, 1969,4 from January 1, 1970, to December 31, 1974,5 and from January 1, 1975, to December 31, 1979;6 and the annual lists of Bureau publications and articles from January 1 to December 31, 1980,7 from January 1 to December 31, 1981,8 from January 1 to December 31, 1982,9 and from January 1 to December 31, 1983. 10"

Jan 1, 1985

The United States Bureau of Mines is establishing a computerized mineral inventory system to help the Federal Government appraise its mineral position and prepare programs insuring against critical shortages of materials. This system, called the Minerals Availability System (MAS), is a component of the Bureau's minerals intelligence function designed to conduct and maintain an inventory of minerals important to the Nation. The MAS defines the physical and commercial availability of the mineral resources. Known resources are evaluated and classified by deposit for entry into a computer storage and retrieval system. An integral concern of these evaluations is the cost of mining and beneficiating the ore contained in specific deposits. To meet this concern, a cost handbook was developed as an aid to preparing feasibility-type estimates for capital and operating costs of mining and primary beneficiation of various types of mineral occurrences. Cost data, obtained from U.S. and Canadian companies, were used as the basis of this handbook. The handbook presents cost curves and equations for each component of the mining and beneficiation process. Factors for each cost component are also given, thereby allowing the updating of cost for time, geographic location, labor rates, and mining and milling conditions. Included in the latter conditions are items such as the length of haul, need for rock bolts, and a rock work index for ores and rocks of various hardnesses. 1.2. USE OF THE HANDBOOK Using the handbook a feasibility-type estimate falling within 25% of expected actual cost is obtainable by summarizing cost components. This handbook should not be used to determine the cost of any single component of a mining or beneficiation system, as any single component may not fall within the 257 limit. It must be understood that anyone who uses the handbook must have a comprehensive knowledge of mining and processing technology and cost estimating procedures. The handbook was intended to be used internally by the Minerals Availability System. Because

Jan 1, 2012

By D. Harrington

The mining industry of the United States has-long been severely criticized because of its high rate of accident occurrence, net only as compared with other major industries-in the United States but also with the mining industries of other countries particularly Europe. Statistics (often not of strictly comparable nature) indicate that the accident-frequency rate in all mining is currently about three times and the accident-severity rate is about seven times as great as the average for general industrial work in the United States. These figures are by no means comforting to humanitarian mining men, irrespective of their status in. the industry, and they constitute a challenge that certainly cannot continue to be ignored much longer. This picture becomes much darker when the above statistics are augmented with data indicating that. on an exposure basis our mines (more particularly our coal mines) have accident rates two, three, or even more times as great as more or less similar types of mines in Europe, particularly England and Wales, Belgium, France, and Germany. However, these foreign accident statistics should be carefully analyzed before we become very mush concerned about them, because they are clot strictly comparable owing to several considerations, not the least of which is the fact that foreign methods of compiling or recording accident statistics often differ materially from ours. Moreover, foreign mining and other conditions axe definitely dissimilar to ours in many if not most phases, and numerous ether factors affect the comparability of foreign mine-accident statistics with ours. Unquestionably it should also be taken into consideration that the accident rate of the 130,000,000 or more constituting the populace of the United. States as a whole is much higher than that of any other major country in the world and is two, throe, or more times the rate of the European countries that have more favorable mine-accident rates than those of the United States. Moreover, it is significant that the mine-accident-severity- rate of British mines is about six times the average accident-severity rate of the major industries of the British Isles, or but little mere, favorable than the comparable figures in the United States, namely, that mining-has an accident-severity rate about seven times that of the average of about 30 of the major industries of this country.

Jan 1, 1941

By Hugh M. Wolfin

This Information Circular is an abstract of a manuscript which was completed in June 1933, by Mr. Hugh M. Wolflin, formerly of the U. S. Bur eau of Mines. This abstract has been prepared by Charles Will Wright for presentation at the February meeting of the American Institute of Mining and Metallurgical Engineers in New York. It has been necessary to omit many of the details and most of the cost data and tables, as well as the illustrations in the original manuscript. As the use of airplanes in mining developments is making such progress and as a publication on this subject to be of greatest value should include the most recent information, it is unfortunate that, due to a lack of printing funds, it has not been possible to publish this manuscript. The purposes of Mr. Wolflin's paper are: (1) To describe briefly what has been accomplished in some outstanding examples by the use of aircraft in the mining and petroleum industries, (2) To record costs, (3) To present available information and suggestions to assist in solving future air-transportation problems in the industries under consideration.

Jan 1, 1934

By Theron A. Klinefelter, Sidney Speil, Sidney Gottlied

"INTRODUCTION The investigation of domestic talcs by the United States Department of the Interior Bureau of Mines, was initiated in December 1941 at the request Gen. Charles Hines of the United States Army. The urgency for such study was expressed by General Hines as follows:The radio-manufacturing industry has recently been expanded by the Army to provide sufficient, capacity for defense needs, and considerable concern has been expressed by the supply Arms and Services over maintaining continued availability of supplies of the necessary raw material. These ceramic products are used by the Signal Cores in all Army radio equipment, and to a greater degree in the new special ultra-high-frequency equipment. The Air Corps has recently become a user large amounts of radio-grade ceramics for aircraft spark-plug covers required for high-altitude operations. In addition, the use of this material is essential to the proper functioning of the radio-navigation aids of the Civil Aeronautics Board.Progress in the Bureau of Mines studies on talc was made available to representatives of the Army and Navy through frequent interim reports. Through the efforts of the several war agencies concerned with raw-materials supply and the domestic talc producers, the condition of scarcity that developed in 1942 passed to one of ease in 1943, and has so continued to date. Tentative estimate of reserves delineated indicates a supply of high-grade steatite sufficient to meet military war requirements for at least 4 or 5 years."

Apr 1, 1945

By Rita D. Sylvester

"This compilation lists and summarizes publications by Bureau authors published in the regular Bureau of Mines series, in scientific, technical, or trade journals, or in other media; those available from the Bureau of Mines are indicated. Patents issued to Bureau personnel are also listed, and instructions are given on how to apply for permission to use them. One of the outstanding features of this Special Publication is an exhausive subject and author index. IntroductionThe Bureau of Mines was established in the public interest to conduct inquiries and scientific and technologic investigations concerning mining and the preparation, treatment and utilization of mineral substances; to promote health and safety in the mineral industries; to conserve material resources and present their waste; to further economic development; to increase efficiency in the mining, metallurgical, quarrying, and other mineral industries; and to inquire into the economic conditions affecting those industries, The organic act of the Bureau, as amended by Congress and approved February 25, 1913, made it the province and duty of the Bureau to ""disseminate information concerning these subjects in such manner as will best carry out the purposes of this Act.""In accordance with this directive, the Bureau reports the findings of its research and investigations in its own series of publications and also in articles that appear in scientific, technical, and trade journals; in proceedings of conventions and seminar's; in reference books; and in other non-Bureau publications. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make the kind of list and index presented in this special publication both necessary and valuable. This issue describes reports and articles published during the period January 1, 1970, to December 31, 1974. It supplements the 50-year list of Bureau publications issued from July 1, 1910, to January 1, 1960;2 the 50-year list of articles by Bureau authors published outside the Bureau from July 1, 1910, to January 1, 1960;3 and the 5-year lists of Bureau publications and articles from January I, 1960, to December 31, 1964,4 and from January I, 1965, to December 31, 1969.5 It includes all the material in the four annual lists of Bureau publications and articles from January 1, 1970, to December 31, 1973."

Jan 1, 1975

"M bed, Matanuska valley, Alaska, coal carbonizingproperties B 510M spectral lines, low-energy, study RI 5538Mab shaft, Leadvile district, Colo., investigation RI .1518Maberry process, for aluminum chloride TP 321"

Jan 1, 1960

By R. K. Guthrie, H. B. Hill

"INTRODUCTION The Rodessa oil field in Marion and Cass Counties, Tex., Miller County, Ark., and Caddo Parish, La., was discovered in August 1930, when a well drilled to a depth of 5,506 feet in Caddo Parish, close to the surface trace of the Rodessa fault, produced gas in commercial quantities. During the next 5 years 21 gas wells were drilled, and a large reserve of natural gas was developed in the high part of the Rodessa structure underlying the Massive Anhydrite member of the Glen Rose formation.In July 1935 oil was discovered on the flank of the structure when a well drilled to 6,048 feet also in Caddo Parish, was completed as an oil well. The discovery of oil in the Rodessa structure initiated art intensive development program of more than usual interest to geologists, engineers, and operators in the petroleum and natural-gas industry. The complex nature of the different reservoirs, the large volume of ""free"" gas under high pressures and temperatures in the upper part of the reservoirs, and the high gas:oil ratios of some of the wells during the early production of oil presented many problems the solution of which taxed the ingenuity of those responsible for the development and exploitation of the Rodessa field.Early waste of gas and resultant dissipation of reservoir energy led to State intervention, which brought about effective regulation of the quantity of gas blown to the air. Oil production from wells producing more than 2.000 cubic feet of gas per barrel of oil was restricted, and oil allowables generally were based equally upon acreage and upon reservoir pressures. Consequently, oil-production statistics of the field are closely associated with gas:oil ratios and reservoir pressures.The primary object of this report is to present factual and statistical data on well performance in the Rodessa field and to show established trends under certain operating methods and practices in high-pressure gaseous reservoirs, which have been carefully developed and outlined by modern technique and exploited under close engineering supervision.The large size of the Rodessa field, it’s fairly well defined gas caps, and a somewhat definite water table in a part- of the oil- and gas-producing region are of special interest and importance in a study of the fluid and energy relationships in reservoirs. Consequently, the results of much of the authors' work in collecting and compiling date are presented in the form of tables, maps and cross sections to show the relative thicknesses of the different oil-and gas-producing members and their permeability and porosity relationships, and, when possible, the variations in stratigraphy are exhibited in cross sections. Results of a detailed analysis of cores from a number of wells also are presented in tabular and graphic form."

Aug 1, 1943

By J. D. Bardill

"The Stoddard mine, Cheshire County, N. H., was explored by the Bureau of Mines in 1944 as a source of the strategic fluorite. It was reported that the vein persisted in the bottom of old workings and the geology of the immediate area indicated the possibility of finding additional lenses.In its program of exploration of mineral deposits, the Bureau of Nines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts pre¬liminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director.Special acknowledgment is expressed for the cooperation and assistance given by Robert F. Sherwood of the United Feldspar & Minerals Corp.; by McHenry Mosier, chief, College Park Division, Mining Branch, who aided in re¬vising this report; and by J. B. Zadra, chief, College Park Division, Metallurgical Branch, and others of his staff, who assisted in performing the beneficiation tests and analyzing samples. The field work was under the direction of Harry P. Hermance.The property lies on the southern boundary of the town of Westmoreland, Cheshire County, N. H., at approximately 72° 39’ west longitude, 42° 27’ north latitude, in the Keene, N. H. (G.S.) quadrangle.Good gravel roads lead from paved State Highway 63 to the property. A dirt road in fair condition suitable for truck leads to the nine.Dwight H. Smith, Putney, Vt., is the owner and has leased the property to the United Feldspar & Minerals Corp., 10 East 40th Street, New York 16, N. Y.Property titles were not investigated.The fluorite deposits of Cheshire Count', H. H., have been known for many years, being reported by Jackson, (Geology and Mineralogy of New Hampshire, by Charles T, Jackson, 1844) and by Hitchcock, in1878 (Geology of Now Hampshire, vol. 3, 1878, by Charles H. Hitchcock). A large pit on the largest or east vein was mined by Lovat Frazer from about 1908 to 1917, This operation is reported to have produced approximately 3,500 tons of fluorspar. In 1917, the American Steel & Wire Co, took over the mine end is said to have produced 3,500 tons of fluorspar before relinquishing the lease in 1923.From 1935 to 1937 the New Hampshire Fluorspar Cc. operated the Stoddard mine, working chiefly on the most westerly of the three known veins on the property, as well as doing some preliminary work on the small central vein. In 1938, the United Feldspar 6 Minerals Corp. leased the mine, and less than 100 tons of fluorspar was produced from exploration and development work, No mining has been done since that time."

Sep 1, 1946

By Charles Enzian, Donald F. MacDonald

It is a far cry from the small and uncertain mining efforts of 50 years ago to the splendidly equipped and solidly financed organiza- tions that now handle thousands of tons of ore per day. The old mining was largely speculative; the new is practically on a manu- facturing basis. In the old days of mining the aim was, chiefly, to find comparatively rich ore; modern practice looks more toward efficiency in mining and milling, so that vast tonnages of low-grade material may be worked at a profit. The old operators had faith and hoped for good returns; the new ascertain with a fair degree of precision what the available tonnage is, what the cost of mining and treating the ore will be, the time necessary to exhaust the deposit, the capital required, and the net profits to be made. The old mining was financed on a highly speculative basis, and the value of mining stock was largely controlled by the imaginations of the promoters and of the individual holders. In the new régime the financing of mines is often as conservative as the financing of manufactures or railroads, and the value of stock, quoted on the leading exchanges, is controlled by the carefully estimated profits in sight. Of course, with every legitimate industrial enterprise go certain business risks, and mining is not exempted from these. Then, too, valueless mining as well as valueless industrial stocks are sometimes offered for sale by the intentionally dishonest, or the ignorant. However, the prospective purchaser of a mine nowadays, if he is willing to pay for the services of reputable mining engineers, can obtain information on which to base an opinion as to the quality of his investment. The relatively recent development of cheap and efficient methods of mining and of ore dressing has given value to low-grade ore bodies that a few years ago were almost valueless. The iron mines of northern Minnesota have been fruitful in developing efficiency in mining methods, notably the open-cut methods in which steam shovels strip off the overburden and then load the ore directly into railroad trains for transport to the furnace. In 1907 open-cut mining was applied to the low-grade copper ores of Bingham, Utah, with splendid results, and since then it has won a most important place in the min- ing of large masses of low-grade ores in several other mining regions, especially at Santa Rita, N. Mex.

Jan 1, 1916

By L. D. Tracy

Many bituminous coal-mining companies have inaugurated extensive safety programs, but the failure to have approved or permissible equipment or safe practice in only one part of a mine has resulted in disaster. The necessity of using only equipment bearing the U. S. Bureau of Mines approval plate is emphasized by the fact that many accidents are the direct result of carelessness on the part of trusted employees using non-permissible equipment. A concrete example is found in the case of an explosion on October 26, 1926, in a mine in the Pittsburgh district, Pennsylvania. Story of the Explosion At about 10 o'clock on the night of the explosion an examination was made in No. 2 butt left and parallel off No. 14 north, and was found to be clear of dangerous accumulations of gas. (See figure). Several hours later a crew of two men brought a self-propelling rock-dusting machine within 50 feet of the face of No. 2 butt parallel before they examined for gas. The machine operator found an accumulation of explosive gas about 13 inches from the roof. He began to wave his arms thoroughly mixing the gas and air. Undoubtedly a highly explosive mixture was created, and as the men attempted to run the machine back to fresh air as explosion occurred.

Jan 1, 1927

By R. Van A. Mills

Rapid deterioration and destruction of metal equipment in oil and gas fields cause waste of resources and financial losses that must be lessened or eliminated if operations in many important fields are to continue profitable. The magnitude of this destruction is proved by the huge consumption of iron and steel pipe, tubing, casing, pump valves, and sucker rods to replace worn-out equipment, and by the amount of such equipment that is left in wells or junked. (See PI. I, A and B, and PI. II, A and B, and Fig. 14, p. 61.) This destruction of equipment constitu~es in itself a serious waste, but contingent production troubles, such as underground leakage of oil through defective tubing and pumps, and the consequent loss of oil and gas because of damage to pay sands by infiltrating water and silt, frequent and costly repairs with necessary suspension of production, and the ultimate injury to or loss of valuable wells, often cancel all operating profits. Many of these troubles result from rapid destruction of metal equipment by corrosive waters. The strata penetrated by the wells usually contain saline waters. Certain types of these waters, with their associated gases, are intensely corrosive; they attack well casing or tubing so vigorously as to riddle it with holes, rendering it useless in a few years or even a few months or weeks after it is installed. Pump plungers, working barrels, balls and seats of valves, and screen pipe, as well as lead lines and other surface equipment, are ruined with equal rapidity. The development and application of practical methods to retard or prevent this corrosion are among the most urgent problems of the oil and gas industry. Although much progress has been made in preventing the corrosion of metals, the need for reducing the damage from corrosion in oil and gas fields is still imperative. This is especially true of underground corrosion in the wells, because underground conditions favor corrosion and are difficult to study; hence they have not been thoroughly understood. In efforts to stop ~amage to oil and gas field equipment by corrosion, numerous methods have been proposed or tried with varying success. Some of these methods are cheap and effective. However, it is surprising that in many important fields the damage by corrosion is accepted as necessary or unavoidable, although cheap and effective methods that have been developed and successfully tried elsewhere might greatly reduce the trouble or eliminate it. This bulletin describes common causes and effects of oil and gas field corrosion and outlines methods of abating the damage. In order to accomplish this purpose best, the writer has avoided taking sides in controversies between the advocates of different metals for oil-field use; instead he describes the methods of combating corrosion in the various fields and suggests experiments that may yield valuable results. Throughout the paper he has freely used information from published reports of other investigators.

Jan 1, 1925