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INTRODUCTION The difference between a mineral inventory or mineral reserve and an ore reserve was discussed in the introduction to Chapter 10. The term ore reserve implied mineral in place that is capable of being mined at a profit. Potential profitability of in situ minerals is dependent upon several economic parameters in addition to grade estimates for blocks of the mineral

Jan 1, 1980

By John W. Cloud

The delivery of blows upon roadway structures by the locomotive engine at high speed, althongh long recognized, has, perhaps, not been as generally understood in severity, relation to speed, and cause as is desirable in matters of such importance. Some points of explanation, with illustrative disgrams, are, therefore, submitted to your attention, preparatory to a note 011 " Steel for Bridges," also submitted. In order that a locomotive may run at high rates of speed with-

Jan 1, 1881

By Joseph Hartshorne

Ever since the introduction of the Siemens regenerative furnace, it has been recognized that a certain amount of gas is lost each time the furnace-action is reversed. This loss comes, first, from the gas which passes through the free connection between the stack and the gas-main, which exists during the time the reversing-valve is turning over; and, secondly, from the gas which is in the chamber and flues, from the hearth to the reversing-valve, and which flows back into the stack when the valve is reversed. The amount lost each time is, of course, small; but, since a furnace is reversed from four to six times every hour for, say, 300 days in the year, the aggregate is large enough to be well worth attention. The estimate has been published1 that, in Germany aloue, the loss from the first of the above causes amounts to 500,000 barks per year. The loss from the second cause is, of course, much greater.

Jan 1, 1907

By H. M. Howe, W. E. C. Eustis

The processes which form the subject of this paper have been experimented on in the laboratory of W. E. C. Eustis, but have not passed beyond the experimental stage. The first is the invention of Mr. J. L. Thomson, of Capelton, Quebec, Canada, the others have been invented by the writers. Thomson's PRocess foR the Extraction oF Nickel. This consists essentially in first rendering the nickel magnetic, and then separating it from the materials with which it is mechanically vol. X.—20

Jan 1, 1882

By Lewis Stockett

During the year 1903, a building having machinery corresponding to ail anthracite-coal breaker was erected at the town of Stockett, Cascade county, Mont., for the purpose of breaking-up and cleaning bituminous coal. The coal is mined from a vein of the Kootenai group of the Lower Cretaceous measures having the following section: The vein is nearly horizontal in position, and each bench differs in quality as shown in Table I.

Jan 1, 1905

By Y. P. Chugh, R. A. Missavage

Moisture has been known to influence strata failures in coal mines for a long the. A concise review of what is known about effects of moisture on strata control with emphasis on the Illinois basin coal mines is presented in this paper. Some approaches to mitigate the effects of moisture-leaving coal in the roof, guniting, shotcreting, application of sealants-are then briefly discussed.

Jan 1, 1982

By C. E. Beecher

THE application of gas or air under pressure to obtain more oil from a sand which has been practically exhausted by ordinary production methods has been practiced to a limited extent for many years. Until recently such methods were confined to the Eastern fields, principally those of Ohio and West Virginia, where in many cases the production obtained after applying pressure for a few years was nearly equal to the total production prior to that time which had been obtained by the usual production methods.' As early as 1917, J. 0. Lewis1 called attention to this method of increasing the recovery of oil and cited the phenomenal results obtained by H. E. Smith, I. L. Dunn and 0. C. Dunn, who pioneered the application of air or gas pressure recovery methods. With this information available it would appear that other oil-producing sections of the country have been extremely slow to realize the advantages of repressuring. However, after a few successful projects in the Mid-Continent area, the oil producers appreciated the value of this method for obtaining further and profitable production from their practically exhausted leases and are now making extensive use of it. In general, it has been the practice to apply pressure to the sands when production has declined to a small yield per well. The purpose of this paper is to discuss some of the advantages which may be expected from returning gas under pressure to the oil sands during the early stages of development, before the rock pressure has been dissipated and the gas exhausted, and to stimulate discussion of this subject on which comparatively little actual field data are available.

Jan 1, 1928

By Rana P. Singh

Electrolytic metal reduction operatios in both aqueous and molten salt electrolytes are being studied by digital signal analysis. The purpose is to determine the relationship between the physical processes occurring in the cell and the frequency spectrum of the cell's fluctuating electrical parameters. The fast Fourier transform of cell voltage (in galvanostatic operations) or cell current (in potentiostatic operations) is computed on-line in real time for the electrorefining of zinc in aqueous acid chloride solutions.

Jan 1, 1984

By N. S. Keith

Some time ago, a firm engaged largely in the manufacture of copper sulphate, applied to me for information as to the practicability of obtaining the copper from their mother liquors by means of electricity ; having reference, more especially, to obtaining the electric current from some magneto-electric or dynamo-electric machine. The mother liquors were the result of several solutions of commercial scrap copper, containing impurities, the quantity of which

Jan 1, 1879

By Howard M. Graff, Sidney C. Bouwer

The economics of mining has traditionally been viewed quite apart from the economics of blast furnace operations. It was realized, of course, that blast furnaces would operate best with good raw materials, but the shipping grade of ore, for example, was decided by a sort of collective bargaining process between the ore producers and the blast furnace operators. The mine operators had to keep their costs down, and were usually successful in convincing management that the ore in any particular deposit was endowed by nature with a certain iron content and that the mine grade could not be raised beyond a certain economic limit. The blast furnace operators would have liked a better grade, but as long as they were able to make a fairly good showing it was more or less accepted that they had to take the ore as it came. The mine operators were able to ship to the nation's blast furnaces thousands of tons of iron ore that would be completely unacceptable by present-day standards. As late as the early 1950's, the major steel companies were witnessing an actual decline in the iron content of their incoming ore supply as the mining companies mined progressively leaner material and upgraded it only enough to pass competitive market requirements

Jan 8, 1965

By D. B. Reger

DAVID B. REGER.-T Want to 'add that since this paper was prepared a well is now being; drilled it the location recommended do the last page. It was not, however, done at my instance; it was done at the instance of Dr. White, the State- Geologist of West Virginia, who has been trying for several years to induce the large oil and gas companies to make a test of some of these, deep sands in West Virginia and a well is now just being started in Wood County, right at this immediate

Jan 4, 1917

By F. W. Bloecher, A. M. Gaudin

Using an adsorption-column technique the partition of dodecylamine between quartz and water has been determined at concentrations ranging from 0.5 to 4000 mg per liter. The adsorption varies as the square root of the concentration. Attachment of dodecylamine to quartz is reversible. The amount adsorbed in a flotation operation giving almost complete recovery is under 5 pct of the amount required for a monolayer.

Jan 4, 1950

By Ian William Wark, Keith Leonard Sutherland

MERCAPTOBENZTHIAZOLE and its sodium salt are marketed under the trade names Flotagen and Flotagen S respectively, for use as collectors for cerussite and other minerals. The structural formulas for sodium mercaptobenzthiazole and for sodium ethyl xanthate are: [ ] Chemically there is a resemblance between the two compounds, though the free acid (mercaptobenzthiazole itself) is much more stable than xanthic acid. Both are readily oxidized, e.g., by iodine to disulphides, and can be estimated by iodometric titration. Qualitatively they are similar as collectors in flotation, although there are quantitative differences between them that may be important in practice. It is deduced that the influence of the nitrogen atom is subordinated to that of the sulphur atoms, and that the dominant group of these compounds is the mercapto group -SH or -SNa. The general method of investigation has been based on contact tests. Two temperatures, 10º and 35º C., have been chosen, and with a standard concentration of 20 mg. per liter of mercaptobenzthiazole (i.e., of the free acid) the influence of alkali, cyanide and copper sulphate on contact at sulphide mineral surfaces has been studied. This standard concentration corresponds to about 19 mg. per liter potassium ethyl xanthate; it brings out the differences between the minerals better than a higher concentra-

Jan 1, 1939

By W. R. Ingalls

DURING 1921, the Oklahoma mines dominated the American zinc-producing industry. They comprised the only group that could produce under the adverse conditions that prevailed. At the beginning of 1921, there were about 34 mills in opera-tion in the Tri-state District, out of a total estimated variously at 150 to 200, and these were producing at the rate of about 5000 tons of blende concentrate per week. At the end of 1921, there were about 50 mills in operation. The Tri-state District rates about 80 men to the mine and mill, on-the average. SMELTING The zinc smelters-in 1921 experienced a disastrous year. All of them operated at greatly reduced capacity and probably most of them suffered loss in operations. Smelting costs came down to a considerable extent by virtue of drops in the price for coal, wage reductions and more efficient work, but these ameliorations were insufficient to enable the smelters to come out even. In the Illinois fields, wages at the end of 1921 had been reduced about 37 per cent. from the peak (middle of 1920), but coal continued to be very dear. The operation of works at a low rate of their capacity was a discouraging and expensive condition. At the end of 1921, the zinc-smelting capacity ,of the United States was as follows:

Jan 7, 1922

Advantages to Members of Our Advertising Section.-It is our intention to make the advertising section of the Bulletin as comprehensive as possible, so that members can turn to it for complete information as to where to buy the best mining and metallurgical supplies at the lowest prices. No firms or supplies of dubious reputation are advertised in the Bulletin.. If members, in buying any material, will refer to the advertisement of that material in the Bulletin, or if they do not find it advertised in the Bulletin, will, when ordering, ask the manufacturers why the goods were not advertised in the Institute publication, it will be of material benefit to all of us, because the chief reason why advertisers .are unable to trace direct results is because purchasers do not mention the Bulletin when writing. Finally, if members, when in need of anything whatsoever, will write to the Institute headquarters, an effort will be made to send them a complete list of manufacturers able to supply the desired materials of good quality. The furnishing of these lists will be a benefit to our Advertising Department, as well as to the members. We need .scarcely call attention to the advantages obtained by the members from the motley which advertising brings in, because all this money is returned directly to the members in one form or another.

Jan 7, 1913

In 1910, he was with the Hidalgo Guadalupe, Pachuca, Mexico, and in 1911 was engineer with the Gualcola Mines Co., at Tuquerres, Colombia. In 1913, he returned to the Sout.hwest, and was employed for that yea.r by the Inspiration Cons. Copper Co. at Miami, and in the middle of the following year he became engineer with the Detroit Copper Co., at Morenci. In the autumn of 1914, Mr. Reece, stirred by his English blood, resolved to return to England to take part in the war. At this time he wrote "I think it will be better for me to resign my membership. If I come through all right, I will apply for re-election." The Institute, however, instead of accepting Mr. Reece's resignation, voted him an indefinite leave of absence, and this precedent soon crystallized into the regular procedure, now in force, of remitting the dues of members in active service. On Dec. 17, 1914, he wrote from Montreal that he fully expected to go over shortly in the second contingent from Canada, with Borden's Armored Brigade, operating with armored motor cars. As he said "this will be active enough service to satisfy any enthusiast, as they are used generally for reconnaissance duty." Soren Ringlund Soren Ringlund died suddenly on July 24, 1918, at Fort Logan, Colo., where he was engaged in service with the Medical Department of the U. S. Army. Mr. Ringlund was born in Denmark in 1875. He came to the United States in 1902, and became a citizen in 1908. He graduated as

Jan 1, 1920

By David E. Van Dillen

INTRODUCTION Current design practices for deep tunnels make extensive use of plasticity solutions by Newmark (1970) and Hendron and Aiyer (1971). These solutions are applicable to a circular tunnel subjected to a hydrostatic stress state in a Mohr-Coulomb plastic medium. The role of rockbolts is introduced into these solutions as a uniform internal pressure equivalent to the yield stress of the rockbolt pattern. The application of these solutions is hampered by their inability to consider the biaxial nature of the in-situ stress field or any surcharged stress, such as due to blast loading. As a means of considering the biaxial stress field, designers have turned to relatively costly alternatives, such as the finite element method. The recent work of Detournay (1983) simultaneously provided two generalizations to the state of the art of the analysis of circular tunnels. Whereas the solution of Newmark applies to nondilatant Mohr-Coulomb materials, and that of Hendron and Aiyer applies to materials having associated flow rules, the solution of Detournay covers materials of arbitrary dilatancy. Secondly, Detournay's solution is valid for biaxial stress states, as long as the problem remains statically determinate (St. John, Detournay, and Fairhurst, 1984). The topic of this paper is an investigation of various alternatives for introducing the effects of rockbolts into simple tunnel design charts developed using Detournay's solution. The study was conducted using the BMINES finite element code, into which rockbolt elements have been added (St. John and Van Dillen, 1983). These rockbolt elements allow for plastic deformation of the bolt, bolt

Jan 1, 1984

By H. F. Haller

COLUMBIA-SOUTHERN'S Barberton limestone mine, 8 miles southwest of Akron, Ohio, is a million-ton-per-year producer from a depth of over 2200 ft in a district where other underground mining at this depth is unknown. Mining extracts 46 of the top 51 ft from a formation of Devonian limestone discovered by drilling in the 1890's. The same drilling revealed extensive salt deposits below the lime- stone, which led to the location of the chemical plant at Barberton as a division of the Pittsburgh Plate Glass Co. in 1899. Soda ash was the principal product of the plant, and as production increased the demand for limestone increased. Columbia's first attempt to secure a reliable all-weather source of stone was the development of a quarry at Zanesville, Ohio, in 1919. Zanesville production eliminated some of the stock- piling required by the use of Michigan stone, avail- able only during the lake shipping season. Stone from some Zanesville horizons, however, was found to be more suitable for cement production than for soda ash, and rail transportation remained an important factor. As demand continued to increase, plans were made to develop the Barberton deposit.

Jan 12, 1954

By Öner Yücel, M. Zeki Dogan, A. Metin Ger

Technical and financial feasibility studies conducted at the Middle East Technical University, in Ankara, Turkey, have revealed that a 400 km long prospective slurry pipeline between Hasançelebi and Iskenderun could efficiently and economically transport iron concentrates, with a size of 55%-325 mesh and of amounts varying between 0.25 and 8.0 million tonslyear. Particularly for annual throughputs above 500,000 tons, favorable results have been obtained regarding the processing of the ore, the applicability, the transport cost, and the foreign ex- change currency savings.

Jan 1, 1980

By E. C. Dominguez, H. B. Scharf

The Sparrows Point plant of Bethlehem Steel Co., southeast of Baltimore, is the largest Bethlehem plant, with an annual rated capacity of 6.2 million ingot tons. There is considerable diversity of product, but a high percentage is sheet, tin plate, galvanized sheets, and rod and wire. The large amount of light-weight end product requires a number of pickling installations that necessarily consume large quantities of sulfuric acid. In the coking operations sulfuric acid is also consumed in recovery of ammonia as ammonium sulfate and in treatment of recovered light oil derivatives. Total sulfuric acid consumption in the plant is currently approaching 10,000 tons per month, of which 55 to 60 pct is required for pickling. In 1951 the acute sulfur shortage caused grave concern as to future sulfuric acid supply for the Sparrows Point plant. Raw materials for acid making were already at hand in the form of hydrogen sulfide and pyrites sufficient to produce nearly half the sulfuric acid required at that time. It was also known that the Bethlehem mining activities would produce additional pyrites in the future. Late in 1951 Bethlehem management decided to build a 250-ton sulfuric acid plant at Sparrows Point to utilize these raw materials. The plant was built and put in operation in May 1953. The steel plant has expanded considerably since 1951, and it is now necessary to operate the acid plant far over rated capacity in order to supply plant demand. Production of acid in 1954 amounted to 93,000 tons.

May 1, 1956