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By Walter E. Lewis

This circular presents the method of making tests and apparent results of comparing performance of tungsten carbide insert bits and steel detachable bits by the Cleveland-Cliffs Iron Co. at the company's mines on the Marquette iron range of Michigan. The mines are at Ishpeming and Negaunee, Mich., and include the Cliffs Chaft, Mather "A", Cambria-Jackson, and Mather "B". There are four general characteristic types of high-grade iron ore on the Marquette range. B. H. Boyum2/ classifies the Cliffs Shaft as "hard-ore" and the Cambria-Jackson and Mather "A" as "soft-ore" types of deposit. Shaft sinking through Jasper, slate, and graywacke was in progress at this writing at the Mather "B", with completion at 3,100-foot depth in August 1949. The many different kinds of rock and ore at the mines of the Cleveland- Cliffs Iron Co. and the experimental work being carried on with carbide in- sert bits make it possible to compare, generally, the carbide insert and steel detachable bit. The type of "hard ore" at the Cliffs Shaft mine re- quired close study of the possible use of the insert tit, and their records are more complete than those of the "soft-ore" mines. History and development of tungsten carbide tips inserted in rock drill bits have been covered by R. W. Adamson, C. H. Vivian, R. C. Sullivan,5/ and others. Tungsten carbide insert rock bits have only recently been introduced to the domestic mining industry. Although unusual performance records are being reported at operations employing the insert bits, the general adaptability of the tool to all rock types and the advantages to be gained by using carbide insert tits remains to be demonstrated. Insert-bit performance is being observed at numerous mines and quarries throughout the United States The several mining operations at the Cleveland-Cliffs Iron Co. at Ishpeming, Mich., is one site where exhaustive comparative tests of insert and conventional steel detachable bits are currently in progress. Results to date are sufficiently impressive to be of general interest to the mining

Mar 1, 1950

By E. D. Gardner

"The Bureau of Mines receives many inquiries concerning favorable areas in which to prospect for gold, procedure to be followed, equipment required, and allied subjects. This circular has been prepared for use in reply to these inquiries.Interest in gold mining and prospecting for gold remains steady. From time to time many people take to the field to search for new gold deposits. A large percentage of them have had no previous experience in prospecting for lode gold; this paper has been written with the hope that it might assist these newcomers.A majority of the metal mines in the United States have been discovered by qualified prospectors who were searching for valuable minerals at the time. Chance, however, always has played a large part in finding mineral deposits. Some of the discoveries of the past were made by men on other errands, such as rounding up burros or hunting game. Accidental discoveries of ore bodies have been made in building roads and trails and in excavating for mine struc¬tures. Evidence of ore has been brought to the surface by burrowing animals and by ants; gold found in the craws of fowl has led to discoveries of deposits. Important discoveries have been made by men who had no knowledge of rocks or minerals; on the other hand, many ore bodies have been found by experienced prospectors, sometimes after hundreds of untrained men had already passed over the ground.The prospector who carries on his work diligently and intelligently is of course more likely to be rewarded for his efforts than the lazy or unintelligent worker; nevertheless, it is obvious that if valuable deposits are not present at the place being prospected none will be found. Conscientious and painstaking efforts to trace gold to its source usually disclose nothing more valuable than some narrow, unworkable seams; however, many deposits that were developed into profitable mines were found by this method of prospecting. Although some prospectors have made several lucky strikes, many others have spent their working lives searching for gold without finding anything worth while. Probably only one prospector out of several thousand ever finds anything worth developing. Moreover, only 1 out of every 300 or 400 properties developed becomes a profitable mine.Prospecting was begun in the Western States in the fifties as the miners looked for the source of gold found in placers. The search for gold has been continuous since that time; the number of prospectors in the field at any one time, however, has varied greatly. Except in some desert regions, practicallyall of the placer fields now being worked were discovered by old timers; more-over, most of the important gold districts were found by early prospectors. Important discoveries of lode mines, however, have been made from time to time. Most of the area in the mining regions of the West has been searched many times by prospectors, and nearly all of the easily found deposits have been located, but it is reasonable to expect that new gold mines will continue to be found. Most of the future discoveries undoubtedly will be of deposits that do not outcrop. Prospecting for such deposits requires considerable digging.Several important discoveries were made in 1934. One of these, the Rogers-Gentry gold mine at the edge of Antelope Valley in Los Angeles County, Calif., was found by an experienced prospector on an old patented homestead a number of miles from the nearest producing mine. The initial discovery at this mine was an iron-stained, decomposed, silicous limestone outcrop, with no vein structure evident at the surface, near a small, barren quartz outcrop and a water seep. Another discovery, the Silver Queen gold mine, in the same general region and near Mojave, Calif., was found by an experienced miner on an open fraction 400 by 1,400 feet in size between two old properties that were thought to have been worked out years ago. The Silver Queen discovery was made as the result of finding a"

Feb 1, 1950

By R. W. Stahl, H. E. Sanford, J. B. Benson

Immediately following the capitulation of Germany in World War II, the German State was occupied by various allied forces, who supervised all indus- trial activities in the area. Coal production is vital to the industrial life of Germany, and most of the coal is mined in the American- and British- occupied zones of western Germany. The British-occupied zones include the Aachen and Ruhr districts, from which approximately 90 percent of the coal is obtained. Figure 1 is a map of the Ruhr district. Because of the magni- tude of the task of insuring an adequate supply of coal and the necessity for united action, it was deemed best to reorganize the coal-producing facilities in the British zone undor the joint supervision of American and British authorities. As a result, the UK/US Coal Control Group was established accord- ing to the organization plan indicated in figure 2. Headquarters for the group was established at Essen, in Villa Huegol, the prewar home of the Krupp family (fig. 3). One of the many problems recognized immediately by the UK/US Coal Control Group was the necessity of preventing disasters and reducing accidents to work- men in mines undor military-governmont control. Consequently, the United States Bureau of Mines was requested to furnish the services of qualified men to search for the hazards incident to coal mining and to prepare comprehensive reports on the results of their investigations. The authors, who wore selected for this task, spont about a year in Germany and visited all except a few of the smaller mince. Whereas their principal purpose was to investi- gate safety conditions, somo of the operating conditions and practices also wore studied. The results of the studies and investigations are embodied in this circular with the hope that some useful information will be disseminated to the mining industry of the United States, including supervisory officials, safety directors, engineers, and mine workmon.

Feb 1, 1950

By Glenn C. Reed

This report is one of a series based upon investigations made and being made within the Missouri River Basin in Montana by engineers of the Bureau of Mines , Albany Branch , Mining Division . These investigations are made primarily to provide preliminary information to the Department of Interior agencies and to others concerned with planning the proposed Federal power development within the Missouri River Basin . The present report has been designed to permit public distribution of factual data obtained . The field investigations were made during the late fall of 1947 and the summer of 1948. Information on mineral occurrences in several areas in Sweet Grass County also are included in this report because of their close proximity to Park County . Practically all known metallic mineral deposits within Park County were investigated ; some nonmetallic mineral deposits also were investigated. The investigations of the metallic mineral deposits in Park County cannot be considered complete ; some long inactive mines and prospects on which little or no information is of record may have been missed . Many of the underground openings , especially at the long inactive properties , no longer are accessible ; consequently , much of the information regarding history their and development necessarily has been obtained from available Federal and State publications .

Feb 1, 1950

By Paul M. Tyler

According to Lindgren , the economic importance of pegmatites stems from the fact that they represent the principal natural storehouse of two classes of mineral products : (1 ) common minerals in exceptional size and purity and ( 2 ) several of the rarest minerals , which are not commercially available from other types of deposits . Most pegmatites can be described simply as coarse- to very coarsegrained granites . Pegmatite includes coarse -textured igneous rocks of any composition , such as syenitic , alkali syenitic , dioritic , or gabbroitic ; but basic pegmatites are far less common than those that are associated with acid rocks and correspond approximately to the mineral composition of ordinary granite . Moreover , only a very few basic pegmatites can be considered as economic sources of useful minerals . Whereas , in ordinary granitic rocks the individual minerals usually measure 1/8 to 1/4 inch across , in pegmatites they are characteristically over 1 inch and often more than 12 inches in diameter . Although some of the constituents of the pegmatite may be only a fraction of an inch in length , single crystals more than 10 feet long are by no means unusual , and some crystals are enormous . A whole quarry was operated in the Urals within a single crystal of feldspar . Huge quartz crystals are quite common although usually imperfect . Muscovite plates 10 feet in diameter have been mined in India , and the Purdy mica mine in Canada contained a mica crystal measuring 6.5 by 9.5 feet and weighing nearly 7 tons , which supplied more than $20,000 worth of trimmed mica sheet . A loglike crystal of spodumene in the Etta mine in the Black Hills of South Dakota was 42 feet long . Giant crystals of beryl weighing several tons apiece have been mined from several properties . Because so many rare minerals are found in substantial concentration only in pegmatites , it is a common fallacy to suppose that pegmatites are always enriched in rare elements . Traces of most of these elements , of course , are found in almost all igneous rocks , and they reappear in the sediments derived from igneous rocks . It does not follow , however , that all or even most pegmatites contain higher percentages of rare elements than other granitic rocks . Geological evidence points to the probability that notable concentrations of rarer minerals or elements in pegmatites are more or less fortuituous , such additions often being ascribed to events subsequent to the original emplacement of the main body of the pegmatite . Most pegmatites consist principally of potash , feldspar , and quartz . Even mica , although commonly present , is not an essential constituent . Probably

Feb 1, 1950

By R. A. Cattell

Progress of Bureau of Mines research related to oil and gas during the past fiscal year has been marked by the publication of more than 40 reports on the various phases of the work . These include papers dealing with the production of oil and gas , transportation of gas , chemistry and refining of petroleum , thermodynamic properties of hydrocarbons , and the processing and utiliza- tion of helium . As an additional service to Pennsylvania oil operators , a new suboffice was opened in Bradford , Pa . , during the year . With this addition , the work of the Petroleum and Natural Gas Branch of the Bureau of Mines is now conducted in two large stations , the Petroleum Experiment Station , Bartlesville , Okla . , and the Petroleum and Oil Shale Experiment Station , Laramie , Wyo . , and three field offices and laboratories at San Francisco , Calif . , Dallas , Tex . , and Franklin, Pa., and two suboffices, Wichita Falls, Tex., and the newly opened suboffice at Bradford, Pa. In addition, this Branch operates large-scale helium-production plants in Texas, Kansas, and New Mexico, and maintains ex- tensive helium-bearing gas reserves in Texas and New Mexico. All helium opera- tions are supervised from headquarters at Amarillo, Tex. A small headquarters staff is in Washington, D. C. A backward glance at the road traveled during the past several years by the Petroleum and Natural Gas Eranch of the Bureau of Mines brings out a general background for the events of the fiscal year 1949. Throughout the fiscal year 1945, the activities of the Branch were still mainly concerned with such war activities as making special field studies for the Petroleum Adminis- tration for War, finding ways of increasing rates of production, and supplying data pertaining to the manufacture of aviation and jet-propulsion fuels. A period of adjustment came in 1946, characterized by a turning from war to peace procedures and efforts to give wide distribution to technical facts ob tained in wartime research; also, there came a realization that the demands of war had broadened the horizons of research. This was emphasized in 1947, when a peacetime program was restored, based upon the long view of the Bureau's place as a research agency in oil and gas. Close attention was given to tech- nical detail in 1948, and emphasis was placed on maintaining a balance between the industrial need for technical knowledge and Governmental-research possi- bilities in the fields of (1) withdrawal of petroleum from natural deposits, (2) utilization of petroleum and its products, and (3) commercial utilization of helium. Studies of petroleum production and utilization and helium production and utilization are the normal functions of the Branch. These functions (sometimes expressed in different words) have been the mainstay of this organization since initiation of the work. The details of approach vary with changing conditions, but, fundamentally, the functions have been the same in both peace and war. The work of the past fiscal year has emphasized the advantages that accrue when Government and industry join in a wise use of technical and scientific knowledge gained through research. Outstanding evidence of the beneficial results of cooperative effort by the Bureau of Mines and various organizations is found in the following typical examples, the details of which are discussed in the body of this report. Working in close cooperation with operators along the Gulf Coast, the Natural Gasoline Association of America, and the National Association of Cor- rosion Engineers, the Bureau found, through field testing, that corrosion protection by means of chromates in high-pressure gas-condensate wells costs less than $1 per million cubic feet of gas produced. Laboratory experiments to measure the corrosion effects of carbonic and propionic acids on various steels and alloy steels gave data that will serve as guides in the selection of new. materials for the construction of well equipment to be tested by industry under actual service conditions.

Feb 1, 1950

Birmingham - A City With a Future COURTING new industries is the time honored duty of the chambers of commerce; but Birmingham, until recently, has done its courting without the benefit of troubadors. This is all changed now for the iron and steel industry is singing an enticing song about steel priorities for new industries from Birmingham's own mills. Along with the increasing industrialization of Birmingham there has been a marked influx of industry into the Southeast and neighboring areas in the south central states which augurs well for business in Birmingham. This important stronghold of the foundry industry (consuming 95 pct of Birmingham's merchant pig iron in 1950) has been the source of important announcements about additions to steel ingot capacity. The virtual abolition of basing point pricing gives the Birmingham iron and steel industry an advantage in the South's new markets. This means more business for Birmingham, but the problem of raw materials supplies is posed.

Jan 12, 1950

By Leland H. Johnson

THE Tennessee Coal, Iron & Railroad Co.'s ore mines began experimental tests with trackless mining units early in 1947. The units had many weaknesses to overcome, but are now well beyond the experimental stage and are becoming a necessity to ore seams that are amenable to this type of equipment. The development of this type of mining with the problems of increased underground supervision, maintenance, and training personnel, along with the benefits derived, are discussed.

Jan 12, 1950

By John V. Beall

THIS is not simply the story of how a water filled shaft was developed into a million-ton- a-year producing mine in the space of four critical years, although it is reason enough for telling it, but it is also the saga of an engineering achievement in which knowledge nurtured by years of experience in coal and ore mines was blended together and the best from each type of mining selected. The entire system of mining was detailed on maps by the mining engineering department before the shaft was unwatered, and subsequent development followed these plans nearly to perfection. The selection of machinery was particularly critical as it was necessary to push production from only a few headings in the early stages of development and metal mine machinery was being used in a coal panel-system of mining.

Jan 12, 1950

By H. F. Ameen, F. M. Hamilton

Results of a laboratory investigation of some sintering variables are presented. The effect on physical properties of mix component variation and rate of cooling of the sinter is illustrated by crush and tumbler test results and data of reducibility tests and microscopic examination of sinters are shown. The results of using solid additions in the mix to improve bed permeability are given.

Jan 12, 1950

Discovery of a hitherto unsuspected extension of the Vermilion range iron formation in Northern St. Louis County, Minn., has been announced by the director of the State's geological survey, Dr. George M. Schwartz. USGS aeromagnetic maps show that the Vermilion range curves southeast from the Tower-Soudan area into the wilderness between Embarrass and Bear Head Lake. Dr. Schwartz believes that this new information justifies considerable exploration and drilling for iron ore in an area of about 20 sq miles southeast of Soudan. The aerial maps were a result of a three year USGS-Minnesota Geological Survey aerial search for iron formations in a 30,000 sq mile area in northern Minnesota.

Jan 12, 1950

BROWN iron ore reserves of Franklin county are being proved economical by Heavy-Media separation at the Blackburn mine of the Shook & Fletcher Supply Co. about 120 miles north-west of Birmingham. The ore occurs under a cover of ferruginous chert and gravel and these materials are also disclosed as streaks in the ore body as it is mined. Previous methods of jigging and hand sorting the ore became too expensive because of rising wages but the use of Heavy-Media separation has proved economical and is making Franklin county the most promising source of additional reserves of brown ore.

Jan 12, 1950

New Products Equipment

Jan 12, 1950

By R. R. Estill

THE rank of the Ruhr coal ranges from a high volatile bituminous coal to an anthracite, depending to some extent on the original depth of the seam. The average Ruhr coal corresponds to a soft bituminous American coal of a coking quality. The average thicknesses of individual coal seams being mined are also comparable (59 in. against 65 in. in the United States). However, consideration of seam conditions and mining conditions other than those just mentioned emphasizes differences rather than similarities with United States soft coal. In general, the Ruhr seams now being mined are much more folded and inclined than American seams. Dips of 20" and 30" are common in seams now being worked, and 30 pct of the coal reserves in the district are in seams dipping more than 35". Only on the tops and bottoms of folds do we find rather flat coal seams. In addition to the folding there is extensive displacement by cross faulting plus a certain amount of strike faulting of an overthrust nature, which results locally in doubling or omission of seams. Because of the long history of mining in the Ruhr, nearly all coal lying near the surface has long since been mined out, and we find that the average depth of mining is at present about 2300 ft below the surface. Deep mining, folding, and faulting result in seam conditions requiring a great deal more roof support than one finds in American soft coal mines. In fact only in the anthracite district and the Rocky Mountain and Pacific coal fields do we find somewhat similar conditions. It is easy to say, therefore, that the problem of mechanization of coal cutting and loading in the German mines is quite different from that which we have so effectively met in America with our mobile cutters and loaders, duck bill loaders, and a room and pillar system of mining our drift and slope mines.

Jan 12, 1950

By H. J. Hager

The Alabama By-Products Corp. is an entirely independent Alabama enterprise. Organization of the company stemmed from the consolidation of three important properties in the Birmingham District and a by-product coke plant at Tarrant, Ala. In 1924 ABC was merged with the Pratt Consolidated Coal Co. This merger greatly extended the company's holdings of valuable coal lands in Walker and Jefferson Counties.

Jan 12, 1950

By Joseph P. Lyden

In the Picher field, structure made openings for the circulation of the mineralizing solutions by flexing, shearing, and fracturing the sedimentary beds. This structure is used with the spatial and genetic relationship of the ore minerals, sphalerite and galena, and the gangue minerals, dolomite and jasperoid, in prospecting for ore bodies.

Jan 12, 1950

By John J. Strohl, Henry J. Schwellenbach

This paper relates the results obtained by decreasing the size of feed to a rod mill screen circuit. As would be expected, added production was gained and a finer grind with no tonnage loss was made possible.

Jan 12, 1950

By Ballard H. Clemmons

THE future of the steelmaking industry of the Birmingham, Ala., district is closely related to and, in a large measure, dependent on the development of workable, economic processes of ore concentration. Operations thus far in the area have been possible only because of the fortuitous occurrence of iron ore, fluxing stone, and coking coal-all the primary iron-making materials within a 25-mile radius of the blast furnaces.

Jan 12, 1950

* George M. Humphrey, president of the M. A. Hanna Co. and of the Iron Ore Co. of Canada, has announced arrangements for financing the development of the Labrador-Quebec iron ore deposits in the total amount of $200 million. Plans call for immediately beginning the construction of mining, railroad, and handling facilities, and contemplate the start of ore shipments in 1955 which will reach 10 million tons a year shortly thereafter. Total drilled and proven ore now exceeds 400 million tons of high grade open-pit ore with prospects for large additional tonnages. Capital structure of the company authorizes up to $125 million of first mortgage bonds, $40 million of income debentures and $60 million of common stock.

Jan 12, 1950

By E. C. Wright

FOR many years the cost of making pig iron and steel in the Birmingham district has been about the lowest in the United States. The close proximity of the important raw materials such as coal, iron ore, limestone, and the large available scrap supply made it possible to assemble all of the important ingredients necessary for steel-making with only nominal costs for transportation. Both iron ore and coal were being mined in this district at one time for about $1 per ton from underground operations. At that time mining wages were low everywhere and the labor rate in the South was considerably below that of other mining districts. This situation persisted until the emergence of labor unions as an economic and political force, emigation of southern labor to northern plants, and continued growth of industry in the South in the years following the depression of 1932. Since that time union organizing of miners and steel workers throughout the nation has increased labor costs in mining and steelmaking. This influence has been felt particularly in underground mining operations since the proportion of labor cost to total cost is still high. The previous advantage in basic labor rate in the South has been almost entirely eliminated by the equalization of labor rates in basic industries by national unions.

Jan 12, 1950