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Jan 1, 1939

By Leonard Obert

The ultimate object of this investigation is to develop a method for determining the pressure, in- situ, on rock mine pillars, arches, end other mire structures. The preliminary investigations of Bureau of Mines engineers, as well as those of other investigations4/ have shown that, the velocity of sound depends on the pressure if it is dependent to such an extent that a measurement of the velocity might be used as a means of determining the pressure, a sonic method of measuring the pressure on rock mine columns is possible. Briefly the method would require, first, laboratory determination of the variation of the velocity of sound with pressure in samples of rocks taken from mine pillars to establish a. velocity-pressure relationship for the type of rock and, next, measurements of the velocity of sound in the mine pillars from which the laboratory samples were taken. The pressure on the pillars could be determined by correlating the velocity in the pillar with the velocity-pressure relationship established in the laboratory. Obviously the success of the method depends on the extent to which the velocity of sound varies with pressure in rock.

Jan 1, 1939

By Nico Van Wingen

Experiments performed with distilled water, unconsolidated sand and dead oil for the purpose of determining the influence of oil flow on the water content of sands were described. While results found are not necessarily, therefore, identical with those that would be obtained under natural petroleum reservoir conditions, the following conclusions were drawn. 1. When oil under constant head is flowed through an unconsolidated sand, the amount of water retained in the core is inversely proportional to the specific permeability of the core. This corroborates the view that the degree to which oil displaces water out of the pore space is limited by the size of the pores. 2. For the range investigated, the displacing action of a more viscous oil of higher specific gravity was found to be the same as a less viscous oil, or lower specific gravity. 3. The amount of interstitial water retained in the sand bears an inverse relationship to the pressure head of the displacing liquid. 4. The degree of retained water saturation of the sand appears to approach 100 per cent as the specific permeability approaches zero. 5. For the higher values of specific permeability and for the pressure range investigated the remaining amount of water in the sand occupies approximately 10 per cent of the pore space. This, together with the fact that the limiting oil velocity curve approaches approximately 10 per cent water saturation as an asymptote, indicates that beyond this point removal of water is achieved only by a stripping of the grains requiring considerable pressure drops across the sands; or by a balancing of the molecular forces. 6. As the water saturation of the sand exceeds approximately 15 per cent of the pore volume, the permeability of the sand to oil decreases rapidly. 7. Sands with water saturations as high as 40 per cent were found to produce 100 per cent oil.

Jan 1, 1939

By G. Phragmén, A. Hultgren

Page Outline of Progress of Knowledge and Theories about Gas Evolution in Steel Ingots. and Its Influence on Crystallization and Segregation................ 134 Object of Present Investigation........................................... 148 Theoretical Discussion of Process of Solidification........................... 149 Gas Given Off from Rimming Steel during Solidification................... 149 Equilibrium Diagram of the Iron-carbon-oxygen Alloys................... 151 Solidification of Pure Iron-carbon-oxygen Alloys.......................... 157 Solidification when Carbon Monoxide Is Given Off at Constant Pressure... 157 Solidification when Gas Evolution Is Suppressed....................... 158 Schematic Application on Solidification of Rimming-steel Ingots.......... 159 Influence of Manganese, Sulphur and Phosphorus......................... 160 Experimental work..................................................... 162 Liquid Steel and the Mold Gas......................................... 162 Ingots Investigated and Methods Used.................................. 165 Ingot structure....................................................... 174 Structure of Rim Zone.............................................. 174 Structure of Core................................................... 181 Structures Obtained under Special Conditions of Freezing................ 182 Distribution of Metalloids............................................. 187 Other Observations Made............................................. 192 General Discussion of Solidification Process................................. 195 Condition of Liquid Steel before Casting................................. 195 Rimming Period...................................................... 202 Composition of Rim Zone............................................. 225 Freezing after Top Is Closed........................................... 228 Slag Inclusions and Ingot Scum........................................ 234 Reaction between Gas in Blowholes and Surrounding Solid Steel during Cooling 235 Summary.............................................................. 237 Appendix—Preparation and Etching of Ingot Sections....................... 238 References............................................................. 239 In 1934, Jernkontoret (The Swedish Ironmasters' Association) appointed a committee for the study of the structure of rimming-steel ingots and the various phenomena associated with their solidification. The members of the committee, including those who have joined it later, have been: I. Bohm, B. D. Enlund, B. Kalling, M. Tigerschiöld, S. Wohlfahrt and the authors. The present paper‡ is a somewhat

Jan 1, 1939

By Ben B. Cox

Oil produced in Iraq for export during 1938 was 31,354,090 bbl., or a daily average of 85,901 bbl; This is an increase of 182,614 bbl., or 0.5 per cent over 1937. All oil exported was produced from the Kirkuk field. The Khanaqin Oil Company, Ltd., a subsidiary of the Anglo-Iranian Oil Company, Ltd., continued to supply local market requirements from its Naft Khaneh field in the Transferred Territories. Slightly more than 32,000,000 bbl. was produced in Iraq, a small part of which was used in field operations. During the year 12 wells were completed and 9 wells were drilling at the end of the year. Of the completions, 5 were producers and 1 was an oil-water level observation well in proved fields, and 6 were listed as failures. Basrah Concession The outstanding event of the year was the granting, by the Kingdom of Iraq, of a 75-year concession embracing approximately 89,000 sq. miles to the Basrah Petroleum Company, Ltd., a British company with French and American participation. The concession covers all parts of the Kingdom, its territorial waters, islands, submerged lands, and its interest in the Neutral Zone separating Iraq and Saudi Arabia that

Jan 1, 1939

By J. R. Thoenen

In the summer of 1937 the authors began a series of time studies of the various processes employed in the production of crushed stone. These studies, made at quarries scattered over the eastern and southeastern parts of the United States, have not been completed, but to make results available to thee industry as early as possible it was decided to publish summaries of the studies made to January 1, 1939, as a series of progress reports. The first of these reports dealt with power-shovel loading and was issued as Report of Investigations 3461 in September 1939. The present circular discusses analyses of the time Studies of the haulage systems at the same quarries. OBJECT OF STUDY The pressure of business problems frequently requires the entire attention of quarry management and in consequence internal plant economies often are neglected, Also, operating officials absorbed in their local problems are prone to overlook possible economies that would attract attention immediately were they critically examining another plant. The authors felt that similar studies of many plants by impartial engineers -would disclose possibilities for cost reduction or greater efficiency in internal plant processes.

Jan 1, 1939

Jan 1, 1939

By E. G. Leonardon, D. C. McCann

The search for oil has required, and without a doubt supplies, a tremendous amount of information on the structure, composition, physical properties, and history of sedimentary rocks. The earliest and most complete source of knowledge is the sample or core of the rock itself, the uses of which are well known. The purpose of this paper is primarily to discuss a new method for obtaining these cores, and to illustrate its use in connection with electrical logs. Most cores have been obtained through a special adaptation of rotary drilling, and the results have been remarkably good, considering the mechanical problems involved. Unfortunately, because of the time and expense, this method cannot be used for the entire length of the drill hole. Even though ingenious contrivances have been evolved in order to reduce the time spent in round trips, such as wire-line coring equipment, mechanical coring still remains too expensive to be carried out continuously. In practice, therefore, one is finally compelled to estimate the probable depths of the more interesting horizons and, allowing a wide margin of safety, to core through those sections only. It is true also that interesting results have been obtained by examining the cuttings brought to the surface by the mud circulated in the well during the process of drilling. Be that as it may, the inescapable fact remains that key horizons may be passed inadvertently, for one reason or another, while the drilling operations are being performed. The only continuous record of the formations encountered is that furnished by electrical surveys. Obviously, it would be desirable to make the electrical survey first and to take the samples from the wall of the hole according to the indications on the electrical log. In this way, it would be possible to core only the exact sections desired, eliminating the otherwise inevitable estimates as to the point at which to start coring, and thereby reducing to a minimum this expensive operation. At the same time this method would provide a maximum of useful samples. A device for taking samples of the formation from the walls of a hole therefore offers the possibility of recovering cores from zones otherwise lost as a source of this type of information. Furthermore, by coring

Jan 1, 1939

By R. E. Heithecker

Almost every oil well drilled into limestone formations in Kansas is treated with hydrochloric (muriatic) acid upon completion: to increase potential capacity of well and thereby increase its "daily allowable" production; to shorten time required to produce recoverable oil; and to increase quantity of oil recovered ultimately from reservoir. Acid treating marked a forward step in the producing fields of Kansas; in fact, many old limestone fields that almost had reached their economic producing limit were "rejuvenated" with acid and their capacities to produce increased several times. It also caused a marked increase in the ultimate oil recovery of some old and nearly depleted fields of Kansas. The effect of the acid was due to the cleaning-out action by the acid at the face of the limestone, the enlargement of the small drainage channels, and the apparent penetration of the acid to previously undrained porous and saturated strata. Studies of the effects of acid were made in the Fairport field, three groups of wells in the El Dorado field and the Shutts field. Estimation of increased recoveries resulting from acid in these fields and groups of wells ranged from 1000 to 2400 bbI. per acre. Limestone structures that had been tested by drilling and found noncommercial were later completed as commerical oil-producing formations through the use of acid. The Kansas City formation, Valley Center field of Kansas, is an example. Increased oil production and revenue from the old fields justified the reconditioning of equipment, which in most cases had become in poor mechanical condition. The first treatment with hydrochloric acid of an oil well in Kansas was in October 1932, and by the end of 1937 almost 6000 wells had been treated. Many wells were treated more than once and the total number of treatments exceeded 8000 by the end of 1937. Approximately 12 3/4 million gallons of acid was required for these treatments. The report includes 15 illustrations and 16 tables.

Jan 1, 1939

Masjid-i-Su1aiman.—There have been no new developments in the Masjid-i-Sulaiman oil fields during the year 1938. In spite of the age of this field, the fall in dome pressure shows no appreciable variation from the low rate of about 0.3 lb. per sq. in. per million tons net production. Drilling has been limited to deepening old wells and to new wells required for maintenance of production and general reservoir control. The rate of offtake has been reduced over the past few years, partly because of depletion of the oil column, and it is expected that future offtake from the Masjid-i-Sulaiman field will be stabilized for some years at around the present figure of 3,000,000 tons per annum. Haft Ke1.—An exploratory well to test deeper formations in the Haft Kel field has proved the existence of productive conditions in the Eocene, which underlies the Asmari limestone (the main producing horizon). Drilling to the northwest in the white-oil springs area has revealed the presence of a separate structure with productive potentialities. One well with a satisfactory production rate has been completed. Offtake from the Haft Kel field has steadily increased since it first came on to production in 1929. Naft-i-Shah.—Production from this field has continued to supply market requirements in northwest Iran. The policy of returning surplus products to the reservoir, which was adopted at the beginning of 1936, has been continued.

Jan 1, 1939

By George A. Moore, Donald P. Smith

In spite of many investigations of the occlusion of hydrogen in iron, the nature of the process and the reasons for the accompanying effects upon the metal are still open questions. This is in large part due to three causes: (1) the difficulty of obtaining iron of adequate purity as starting material; (2) the occurrence of allotropic transformations, which complicate the effects; and (3) the fact that the body-centered cubic modification does not lend itself readily to crystallographic investigation. The present paper attempts a critical review and correlation of the somewhat scattered and disconnected existing observations, and an experimental determination of the extent to which the conclusions that appear to follow from these are applicable to iron of really high purity, studied under well-defined conditions. Review Although only a comparatively few investigations have so far been made on the pure system iron-hydrogen, there is a much larger volume of literature which throws some light on the problem but falls short of a place in the systematic investigations, either because no attempt was made to measure equilibrium conditions or because the metal used was not iron or the gas not pure hydrogen. Such results have been variously dismissed in the past as of no importance, or as too complicated to try to explain; or they have been explained in terms of any of a dozen or more pictures, each of which is contradicted by data from other sources. The present importance of these data thus arises from their very mass and diversity, which present a picture of occlusion as a phenomenon whose variability cannot be ignored. We have attempted to organize the literature into groups comprising similar experiments or data leading to similar conclusions, thus of necessity sacrificing accuracy of historical order. Lattice Occlusion.—Throughout this discussion, the term "lattice occlusion" will be used to denote the formation of a simple solid solution of a gas in a metal lattice, usually of interstitial distribution. The word

Jan 1, 1939

By J. H. Fletcher

ALTHOUGH some mines have been completely mechanized, on the whole mechanical equipment has made slow progress in the coal fields. Coal mining is particularly well adapted to hand labor. The skillful hand miner can keep his working place safe under difficult roof conditions, remove impurities from the coal at the point of origin, and produce a maximum percentage of large-size coal, so as to command the highest price on the market. Hand mining has also the advantage of low capital investment per ton of production and moderate carrying charge when the mine is idle. Though animal haulage gave way to electric locomo-tives and hand cutting to mining machines, beyond these concessions most of the tonnage is still produced by manual labor. But factors over which producers have no control are speeding the change to mechanical mining. The additional investment in underground equipment and surface preparation plant must be offset by a great increase in tons per man-day, and to do this the employees should be able to utilize as much of their time as possible on production. In the installation of mechanical mining, the only change in method usually has been to add loading machines to a mine already developed for hand loading. Because of a lack of suitable equipment, few mobile loading machines have been installed in seams of coal less than 4 ft. thick; the mechanization in the thinner seams has been confined largely to shaking conveyors and hand loading onto chain conveyors. Mechanical mining requires an organization that is prepared to study its particular problem from production territory to market in recognition of the changed factors arising from the use of loading machines at the working face, and other causes, such as safety of men and property; high wage scale on hourly basis; concentrated working territory and rapid extraction from a given area; change in the percentage of sizes of coal produced and effect of this on average realization. There are also the coal-cleaning problem; increased capital investment, maintenance, obsolescence, and the relation of all these to the spread between realiza-tion and production cost. If coal seams were uniform, the answer would

Jan 1, 1939

Jan 1, 1939

By H. E. Stauss

THE short-time tensile-strength test, while it has not attained the practical importance of the creep test at elevated temperatures, has the advantage of being rapid and is satisfactory for determining relative strengths. For platinum and its alloys, which frequently are used at high temperatures under ill-defined conditions, the short-time test provides useful data that aid in the selection of the most promising alloy for each use. Measurements have been made upon 13 alloys, using wire 0.0031 in. in diameter, the choice of alloys and of wire size being determined by the requirements of a practical problem. Later the measurements were extended to higher temperatures by the use of heavier wire, 0.010 in, in diameter. APPARATUS The use of fine wire made the necessary equipment very simple, since no effort was made to measure the elongation. A small platinum-wound horizontal furnace was used, ½ in. in internal diameter by 1 ft. long, with the wire threaded through it. The wire, clamped at one end while the other ran over a ball-bearing pulley, of a total length of 29 in., was loaded directly by running sea sand into an attached basket, making the rate of loading and not of elongation constant. The sand flowed from a funnel, under a head of 3 in., into the basket. 3 in. below the orifice, at the rate of 170 grants per minute. Pulley friction and bending resist-ance of the wire as well as the force of impact of the sand could be neg-lected, being 3 grams and 0.5 grams, respectively. Furnace temperature .was uniform within ±5° C. over a length of 3 in., although a drift with time occurred, the largest amount being 20° C. No provision was necessary for a controlled atmosphere.

Jan 1, 1939

By Patterson B. G

The small party of mining men who formed the original Mount Morgan Syndicate in 1882, commenced operations on the top of the mountain with what were practically nothing more than small hillside quarries, It was not until 1891 that underground stoping began, and open-cut mining therefore commenced with the commencement of operations. This hillside quarrying, however, seems to have been quite haphazard and unsystematic ; there is no trace or sign of any properly devised mining scheme. This can be seen plainly enough from an examination of old mine plans; for in less than five years after stoping was; adopted, the open-cut was down into the stoped-out ground. The following table, prepared from these old plans, shows the downward trend of the excavation in the past fiftyseven years:-

Jan 1, 1939

By E. L. Garton

[Analyses of may crude oils produced in Louisiana are included in reports that t have boon published by the Bureau of Mines. The first report, giving, analyse of 6 Louisiana crude oils, was 3 published in 1921 and this was followed a year later by Report of Investigations 2416,4/ giving 7 additional analyses. The eleven most important of these analyses were incorporated in Bulletin 291.5/ issued in 1928 In 1934 analyses of 26 crude oils produced in southern Louisiana were published.6/ The percent report presents analyses of 72 additional samples of crude oil from 45 fields in 23 parishes In Louisiana.]

Jan 1, 1939

The following list contains the names of members of whose deaths notices have been printed in MINING AND METALLURGY during the year ending April 1, 1939. Biographical sketches published in MINING AND METALLURGY are indicated in the last two columns.

Jan 1, 1939

By Joseph M. Dawson

Although eight new fields were discovered along the south central fault-line district of Texas during 1938, only one can be considered as of major importance. and as a whole the year was one of no very great development. Several prospects, particularly two, were condemned through drilling, which had been considered important for probable Edwards limestone production. The oil produced was approximately the same as during 1937; namely, about 9 million harrels. This, of course, does not represent potential production but that allowed under proration. The year witnessed the very rapid decline of operations and interest in Austin chalk production. It has been found that only in rare instances mill chalk production pay for itself, because the wells decline extremely rapidly and the recovery per acre, formerly estimated at 2500 bbl., is now considered to he around 1000 barrels. There was an intent interest in the drilling arid producing of edge and abandoned properties in the three Edwards lime producing fields; namely, Luling, Salt Flat and Darst Creek. Many good wells were completed on properties formerly considered below the water level or produced beyond the economic limit The Edwards is penetrated only a few inches and a very small charge of acid is used. The results have been surprisingly

Jan 1, 1939

By Edwards A. B

The occurrence of lollingite (FeAs2 ) in the Broken Hill lode is recorded by an analysis of lollingite published in the Annual Report of the Department of Mines, New South Wales, for the year 1934 (p. 69). The analysed specimen came from the North Broken Hill mine, and material from the same occurrence (Specimeh No. 1), as well as two specimens (Nos. 3 and 4) from the Zinc Corporation mine, have been forwarded· to us by Mr. M. Mawby of the Zinc Corporation Mine. This material has been supplemented by another specimen (No. 2) from the Zinc Corporation mine, passed over to us by Dr. I. Wark.The original analysis of lollingite is quoted in Table I, and shows that the Broken Hill lollingite contains appreciable amounts of cobalt and nickel, and, indicates that the iron is to a considerable extent replaced by cobalt and nickel, so that its formula should be written (FeCoNi) As2This is supported by a microscopical examination of a polished surface of the lollingite, in which no individual arsenides of cobalt and nickel can be detected.Coarse grained galena, sphalerite, chalcopyrite, and pyrite are attached to our specimen of lollingite from the North mine, and are separated by a sharp junction from a mass of lollingite associated with some arsenopyrite and garnet. The massive lollingite can be distinguished from arsenopyrite in the hand specimen by a much brighter, silvery lustre, against which arsenopyrite appears a dull silver grey; but the passage from lollingite to arsenopyrite appears transitional.

Jan 1, 1939

By A. J. M. Ross

BACKFILLING of stopes and other underground openings in the Homestake mine with sand tailings was undertaken primarily to reduce surface subsidence, which was wrecking much of the surface plant and a substantial part of the town, and to make possible maintenance of open-ings into the top of pillar stopes as mining progressed. The progress of this type of filling has been rapid and the results very satisfactory. Sand is now used in filling timbered stopes, shrinkage stopes, and abandoned drifts and crosscuts. A permanent pipe-line system for transporting sand tailings into the mine by gravity has been installed. The close filling of all stopes has resulted in important benefits other than the two major ones. The ore bodies in the Homestake mine occur as replacements in one distinctive layer of the metamorphosed pre-Cambrian sediments along a group of minor folds that together form a complex anticline that pitches at 35° to 40° to the southeast. The ore bodies are extraordinary for their magnitude. Widths of over 300 ft. have been mined and continuous ore has been followed for over 1200 ft. along the strike on some of the upper levels. Mining has been by shrinkage stoping with square-set mining of crowns and pillars. In the standard plan, shrinkage stopes 60 ft. in the direction of strike and the full width of the ore have been taken up to within 25 ft. of the level above. After filling, the crown has been mined by square-set methods, as have also the 40-ft. pillars between shrinkage stopes. In former days, when the supply of ore seemed inexhaustible, the mining of pillars was allowed to lag far behind because of the high cost. Many pillars were rather badly fractured on the level and in some places between levels. Coarse waste was used for backfilling all stopes, but in pillars it became increasingly difficult to maintain haulageways for the transporta-tion of this fill over the top of the stopes as mining progressed. The cost of maintaining these crosscuts was excessive and in many pillars prac-tically impossible. Therefore it became the practice to fill pillar stopes by tapping the back and sides of the stopes.

Jan 1, 1939