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By R. U. Jackson

Belt conveying is a method of transportation that requires proper servicing and maintenance if completely economical results are to be obtained from the system. With a trucking system, it is common practice to deliver the trucks to a servicing station each day or at the end of each shift. With railroad transportation there is a similar procedure. Sufficient credit is seldom given to this periodic inspection and maintenance procedure, yet it is the key to the successful operation of trucking and rail haulage systems. How about the belt conveyor transportation system? Here is a system that requires no operator for each individual unit. It requires only a main switch and an adequate sequence interlocking system, and the system is so simple to operate that maintenance is considered as only a casual requirement-nothing is done about it until after trouble has developed.

Jan 1, 1956

Jan 1, 1956

By J. W. Spretnak, R. Speiser, A. M. Adair

THERE are sufficient arguments and evidence to indicate that boron should be adsorbed to existing austenite grain boundaries during the austen-itizing treatment. Accordingly, it is possible that boron contributes to the hardenability of heat-treatable steels by the reduction of the interf acial energy of austenite grain boundaries, at which sites are nucleated heterogeneously the decomposition products of austenite. Such a reduction in interfacial energy would reduce the total energy that can be borrowed in these heterogeneous nudeation processes and thus retard the initiation of transformation. This investigation was undertaken in an attempt to determine the effect of boron on this interfacial

Jan 1, 1956

Jan 1, 1956

For 11 years, under authorization of the Synthetic Liquid Fuels Act of April 5, 1944 (30 U.S.C. 321-325), and amendments, the Bureau of Mines has carried on an extensive research and development program to establish methods for producing oil from coal and from oil shale. This act was passed by the 78th Congress primarily because of the stress of wartime demands for liquid fuels to supply our armed forces during World War II. The act was progressively extended by the 80th and 81st Congresses, as later peace-time demand for oil and oil products continued to increase.

Jan 1, 1956

By John H. Soulé

This paper describes the location and general features of the ?Red Bed? or sandstone copper deposits in southeastern Colorado and New Mexico. Most of the areas containing this type of deposit were visited, and many deposits were examined. Some deposits were not visited because of lack of information as to their location. In the large area covered a great variety of climatic, geographic, and topographic conditions exists. Some of the deposits are in arid areas, whereas others are in heavily forested regions. Altitudes range from 3,400 to 9,200 feet, and the terrain varies from flat plains to rugged mountains. Transportation is a difficult problem in most of the districts, involving long truck hauls to a railroad and long rail hauls to a smelter.

Jan 1, 1956

By E. P. Carman

This report is the 19th in a series summarizing Bureau of Mines research and technologic work on coal and related investigations. The first 17 reports covered fiscal years; however, the 18th report3/ covered the 18 months from July 1, 1952, to December 31, 1953, to permit the publication of this and subsequent reports on a calendar-year basis. Most of the material in this report relates to publications by Bureau authors issued during the reporting period. Some work is referred to on which the results have not yet been published or may not be published for security or other reasons. In a few instances publications are mentioned that were issued before the reporting period but were not included in previous reports. Further details on the published work described herein may be found in the publications cited in the footnotes. Research and technologic work on coal by the Bureau is directed toward developing and encouraging increased conservation of coal resources through safer and more efficient mining, preparation, and utilization. Significant advances were made during the year in these fields, particularly in coal-mine safety and in preparation and utilization of the various ranks of coals.

Jan 1, 1956

Diamond drilling was first carried out at Norseman in the Princess Royal Mine, early in this century. Little concentl'ated drilling was done from then until Western Mining Corporation commenced drilling in 1934. Since then Central Norseman Gold Corporation N.L. has continually employed diamond drilling in exploration of the field. After 1946 the advantage was seen of applying broad pattern surface drilling at Norseman in the reef exploration. In 1953, as a result of the steeply rising cost of drilling and the time taken to penetrate surface material by light equipment, heavier drills and new rigs were introduced. The surface drilling programmes called for a greater monthly or annual footage and to satisfy this new techniques were introduced. The Mitchell-21 machines were discarded and A-3000 machines were installed, firstly under a 48 ft. fixed tower, then mounted on a truck with a 20 ft. tower, and finally on a truck carrying a 40 ft. tower. With the mobile units a compressed air compressor is attached. By use of compressed air with either the Reed roller or Hawthorne bit, rate of penetration of overburden is greatly increased. The mobility of the truck mounted machines has greatly reduced the time required to move from one hole to another, and the use of heavier machines on a three shift per day basis has considerably increased the footage per shift. The general result is an increase to 1,500 ft. of drilling per month per machine, while costs have been greatly reduced in spite of increased wages and diamond prices.The underground drilling technique is described. Analysis of performance has not been made because the drillers performance is subject to shaft routine and service.INTRODUCTIONGold was first discovered at Dundas in 1894, and at Norseman, 14 miles north, in 1895. From that tirpe until 1935 mining activity fluctuated. Following the mining revival in 1935, production in the field has remained comparatively stable. This stability in part has been due to the broader scale of operations of Central Norseman Gold Corporation N.L., and in these operations diamond drilling has played an increasingly important role.

Jan 1, 1956

By Wilbur T. Stuart

TO assist the mining industry in attacking problems of water control, the U. S. Geological Survey has begun a program of research in mining hydrology. In certain fundamental respects water control is similar to development of water supplies from wells or to the drainage of agricultural lands, as many of the tools developed in recent years for quantitative ground-water problems are applicable, with modification, to mine-water problems. In 1952 a 30-day pumping test conducted jointly by the Eureka Corp. Ltd. and the Defense Minerals Exploration Agency provided an opportunity to gain knowledge concerning water movements around a flooded mine shaft. The methods of analyzing the data may be used as a guide for the evaluation of similar problems elsewhere. The Fad shaft of the Eureka Corp. is on Ruby Hill, 1 1/2 miles west of Eureka, Nev. The shaft was completed at a depth of 2465 ft in November 1947 at a site adjacent to the downfaulted block in which the ore was found. As the drift on the 2250 level progressed toward the ore zone, a large flow of water was encountered after the Martin fault was intersected. This flow exceeded the installed pump capacity, and an unsuccessful attempt to recover the shaft and the 2250 level was made in 1948.1, 2 Geology and Hydrology: The complex structure of Ruby Hill is that of an anticline broken first by thrust faulting and later by normal faults. The present orebody comprises several mineralized zones within a block of the Eldorado limestone of middle Cambrian age which was downfaulted 1400 to 1600 ft, and it may be related to a similar body mined at a higher level south of the Ruby Hill fault. At the depth of the largest zone of ore the block is roughly rectangular in shape, about 1000 ft wide and 1500 ft long, and dips about 30" NE, see Fig. 1. It is apparently bounded on the south by the Ruby Hill fault, on the east by the Jackson fault, on the north by the Martin fault, and the west by the Bowman fault. Within the block, but between the Ruby Hill and the Martin faults, are the Office and Adams Hills faults; west of the block and the Bowman fault are the Albion and Spring Valley faults. There are many conflicting reports concerning the water-yielding characteristics of the Eldorado limestone and the condition of the fault zones, that is, whether they are open or tight. However, the diamond-drill records indicate that open spaces as much as 2 or 3 ft across were encountered, and considerable cementing and lining of holes was necessary to maintain circulation of drilling fluid. There is also evidence that the Eldorado limestone was cavernous where it was mined in the early days south of the Ruby Hill fault. At the site of the Fad shaft the formations encountered from the surface down included the Pogonip limestone, Dunderberg shale, Hamburg limestone, and Secret Canyon shale. These formations did not yield large quantities of water to the shaft. The Pogonip limestone, which appears to be permeable and might yield water elsewhere, is above the water table in the vicinity of the shaft. The Secret Canyon shale, immediately overlying the Eldorado in some places but in most places separated from it by the Geddes limestone,3 is apparently tight and does not transmit water. During the 30-day test period the shale briefly confined the water in the underlying formations so that artesian conditions were observed in drillholes E and F, which are cased into the Eldorado limestone, whereas unconfined conditions were observed in drillholes B, C, and D, which were open to the shale. The Geddes limestone, which normally lies between the Secret Canyon shale and the Eldorado limestone, was not encountered in the Fad shaft. The Geddes, a flaggy, fractured limestone, is reported capable of yielding large volumes of water. Water stored in the interstices of this thin-bedded limestone within the Ruby Hill fault zone on the 1200 level of the Locan shaft drowned the pumps in 1923 when the Richmond-Eureka Mining Co. attempted to explore the area along the fault. Eldorado limestone was not encountered in the Fad shaft. In the ore-block area the Eldorado limestone was not entirely offset from other water-yielding formations by movement along the Bowman fault; therefore it may be hydraulically connected with the other formations. Adjacent to the Ruby Hill, Jackson, and Martin faults, the Eldorado lies in contact with other possible water-yielding formations. One of these, the Prospect Mountain quartzite, is separated from the Eldorado by thin, sheared, and broken beds of the Geddes within the Ruby Hill fault zone. A limited examination by the author of the Prospect Mountain quartzite in the Richmond mine at a higher level and south of the Ruby Hill fault indicates that the quartzite is poorly permeable. The monzonite mass south of the quartzite would be a further barrier to the flow of water. The poor permeability of this area is substantiated by records of levels at which water was encountered south of the Ruby Hill fault. In view of the normally low rate of ground-water recharge, if this desert area had been permeable, water levels could not have been maintained at altitudes of many hundred feet above the present water table west and north of Ruby Hill. Thus the ore-bearing block of Eldorado limestone is in contact with possible water-yielding rocks on at least two sides, and if the fault zones are possible conduits for water circulation the geologic and hydrologic conditions are suitable for the infinite-aquifer type of analysis as used and modified here. History of Pumping: During sinking of the Fad shaft a maximum pumping rate of 1500 gpm kept the shaft dewatered sufficiently, but in March 1948, after the 2250 level drift passed through the Martin fault into the Eldorado limestone, the pumps and shaft were flooded. Subsequently additional pump-

Jan 1, 1956

By David Cornell, Yusuf K. Sukkar

The fundamental differential equation for fluid flow has been rearranged, integrated numerically for natural gases, and the results presented in tabular and graphical form suitable for the direct calculation of vertical gas flow problems. The integration is rigorous except for the use of a constant average temperature. Both static and flowing bottom-hole pressures may be calculated by (his method without resort to trial and error procedures. INTRODUCTION Bottom-hole pressures can be determined either by direct measurement with a bottom-hole pressure gauge or by calculation. Since measurement with a bottom-hole pressure gauge is costly, calculation of bottom-hole pressures is to be preferred when possible. Calculation involves knowledge of the wellhead pressure, the properties of the gas, the depth of the well, the flow rate, the temperature of the gas, and the size of the flow line. These quantities must be combined in a suitable equation for vertical flow. Several equations have been developed for the purpose of calculating gas flow through both horizontal and vertical pipes1,2,4,5,6,7,8,9 These equations all have the basic differential equation for flow as their starting point. They differ only in the assumptions which are made in order to simplify the integration step. The bottom-hole pressures calculated using any of the better known equations are in good agreement with bottom-hole pressures calculated by a more rigorous but considerably more tedious stepwise integration method. All of these methods, however. require a trial and error solution for the calculation of flowing bottom-hole pressures. The purpose of this paper is to present a method which provides a direct solution of static and flowing bottom-hole pressures without use of a trial and error solution. At the same time the method involves fewer simplifying assumptions than any of the previous methods used, except lor the lengthy stepwise method. The derivation of any practical flow equation begins with the basic differential equation which is rigorous for almost all flow problems. The five terms in Equation 1 represent the potential energy, the potential energy of position, the kinetic energy, the shaft work done, and the energy losses due to motion of the fluid respectively. Equation 1 reduces to Bernoulli's theorem for the case of horizontal flow of an incompressible fluid, no work done, and no energy losses due to friction. In the present case, the term (v) (dv)/(g,.) can be shown to be quite negligible compared to the other terms, and is therefore neglected in the derivation. The term — dws includes work done by a pump or turbine in the system and is zero in this case. The frictional losses in the pipe are included in the term — d(lw) which is expressed in terms of the Moody friction factor as in Equation 2. (f) (v2) (dL) d(lW) = (f)(V2) (dl)/(2) (g) (d) The specific volume of a gas can be expressed in terms of the temperature, pressure, molecular weight, and compressibility factor. The velocity of the gas can be expressed in terms of the weight rate of flow, the specific volume, and the dimensions of the pipe.The reduced pressure Pr is to be used because z can be expressed as a function of Pr and Tr alone for most natural gases:

Jan 1, 1956

The ready solubility of gold in dilute aqueous solutions of the cyanides of the alkalies or alkaline earths provides a convenient method for the separation of the precious metal -from the large surplus of associated materia1. The finely ground ore is pulped with a weak solution of cyanide, agitated to dissolve the gold, filtered and washed. The lowgrade filtrate is then clarified and the gold precipitated by some electronegative agent, the most usual being finely divided zinc or zinc dust. The slight precipitate is collectedon some form of filter coated with a filter aid, the filter cake being then known as "gold slime".A typical analysis of this slime is given in Table 1.

Jan 1, 1956

By S. J. Aresco

The Bureau of Mines has been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the ash-softening temperature of ash, the free-swelling index, and the Hardgrove grindability index. Under most of these specification contracts the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions~ issued by the Bureau of Mines; the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor and, if it is not, a price adjustment is made. Analyses of the delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous sampling of coal as delivered is a check on the practical results obtained in burning the coal.

Jan 1, 1956

By James Westfield

This report covers the calendar year 1954 and has been prepared and submitted to the Congress of the United States in accordance with the provisions of Sec. 106(a) and Sec. 2l2(c) of the Federal Coal-Mine Safety Act (66 Stat. 692; 30 U.S.C. Sec. 451-483). Background The Federal Coal-Mine Inspection program was established to carry out the provisions of Public Law 49, 77th Congress, H. R. 2082, approved May 7, 1941. This act has since been amended to be known as Title I -Advisory Powers Relating to Health and Safety Conditions in Mines, under Public Law 552, 82d Congress, approved July 16, 1952, which also includes Title II -Prevention of Major Disasters in Mines. Public Law 552 is known as the Federal Coal-Mine Safety Act.

Jan 1, 1956

By H. B. Humphrey

WHEN THE BUREAU OF MINES was created in 1910, the organic act had as one of its main provisions the following: That it shall be the province of said bureau and its director, under the direction of the Secretary of the Interior, to make diligent investigation of the methods of mining, especially in relation to the safely of miners and the appliances best adapted to prevent accidents, the possible improvement of renditions under which mining operations are carried on, the treatment of ores and other mineral substances, the use of explosives and electricity, the prevention of accidents, and other inquiries and technologic investigations pertinent to said industries, and from tinge to time make such public reports of the work, investigations, and information obtained as the Secretary of said department may direct, with the recommendations of such bureau. The nationwide nature of the health and safety work of the Bureau of Mines has given its representatives an opportunity to study and report on matters pertaining to health and safety in mines and related operations from the time the Bureau was established to the present. Regular annual reports and numerous additional papers and reports have been published each year to place on record and to make available the information gathered. While the basic purpose of this bulletin is to describe health and safety reports for the period January 1947 through June 1955, a selected number of earlier publica¬tions that are believed pertinent for reference purposes are included.

Jan 1, 1956

By Joseph Grumer

About a century ago Bunsen and his associates invented the famous burner that bears his name and was to become the ancestor of today's gas appliances. Over the years, Bunsen's invention became the starting point of a highly developed, practical technology that culminated in the gas industry as we now know it. However, it did not occur to the early workers to investigate the scientific potentialities of the new device, and as a result the science of gas-burner performance did not keep pace with the growing industry. It was with the objective of closing the rapidly widening gap between science and technology that the present research was undertaken Its immediate purpose was to provide basic information on the combustion characteristics of .fuel gases, in particular as they affect flashback, blowoff, and yellow tipping. Information obtained in the present research and contained within this report consists of the following: (1) Fundamental flashback and blowoff characteristics have been determined, it is believed, for all fuel-gas mixtures in which the gas industry may be interested. These are critical boundary velocity gradients for flames in free air, on burners with ports at room temperature and pressure. Burner aeration is characterized by the parameter, fraction of stoichiometric. These basic limits are explained, values are presented, and calculation procedure is given for deriving corresponding values of port loading and percent primary air (chs. I and II).

Jan 1, 1956

Jan 1, 1956

Jan 1, 1956

John Chipman (Massachusetts Institute of Technology, Cambridge, Mass.)—After looking over the authors' shoulders for several years and after many discussions on the interesting diagrams of the types shown, it is a pleasure to see a formal paper published on this subject. There can be no doubt of the practical usefulness of the concepts shown. Inclusion formation in steel is such a highly complex matter that any system for understanding the subject is bound to be welcomed by those who must work with steels and who see in their day-to-day experience the good and evil effects of inclusions. A feature of the work with which the discusser has been concerned, and which he would now like to attempt to explain, is the relation between the schematic diagrams which the authors use and the phase diagrams for related systems. Obviously, the authors' diagrams are in no sense complete phase diagrams. However, there is a relation between this type of diagram and the true phase diagram, and the understand- ing of this relation ought to help in understanding the general picture which the authors are presenting. Consider the authors' Fig. 4, which shows the liqui-dus relations in the Fe-Mn-S-0 system. To show the complete relations between temperature and composition in these four ternary systems would require four triangular prisms, the vertical axes of which would represent temperature. The four triangles of Fig. 4 represent basal projections of certain lines from the four prismatic phase diagrams. Readers of the paper are all more or less acquainted with this type of projection and its usefulness and limitations are generally understood. In order to concentrate on the interesting parts and to minimize the less interesting features, the composition scale may be shifted to de-emphasize regions containing gaseous sulphur and oxygen. Such a diagram is shown in Fig. 16, which is a distorted version of the authors' Fig. 4. Here the oxide of iron is wiistite, denoted by W, and it is to be noted that between W and MnO lies the entire MnO-FeO "binary" system. Similarly, between MnS and FeS lies another binary whose

Jan 1, 1956

Impact Transition Temperatures of Some Pearlite-Free Mild Steels As Affected by Heat Treatments in the Alpha Range H. P. Tardif (Canadian Armament Research and Development Establishment, Quebec)—Mr. Josefsson is to be congratulated for his study of a most difficult subject and for the theories proposed to explain the re- sults. One point which, however, might not have received proper attention is that of the shape of the stress-strain curve at the yield point of quenched and furnace-cooled specimens and of specimens strain aged

Jan 1, 1956

DISCUSSION, T. B. King and H. H. Kellogg, Chairmen Philipp Gross (Fulmer Research Institute Ltd., Stoke Poges, England)—As pointed out by the author, any better agreement between experimental and calculated

Jan 1, 1956