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By V. S. Swaminathan

This year, Great Britain is looking back over a century to August 14, 1850, the day when the first "Act for the Inspection of Coal Mines" was passed in that country, an act which signaled the end of over two hundred years of hitherto uncontrolled and dangerous mining practices.

Jan 11, 1950

Jan 11, 1950

CHAIRMAN DOUGHTON of the House Ways and Means Committee announced on September 23 that the committee has scheduled public hearings on an excess-profits tax, beginning on November 15, 1950. In the meantime, the staff of the Joint Committee on Internal Revenue Taxation and the staff of the Treasury Department are to confer jointly on this question in the hope that such conferences may result in the preparation of a report on excess-profits tax proposals which could be used as a basis for testimony before the committee. It is thought that this procedure may aid in the draft of an excess-profits tax bill for introduction in the House when Congress reconvenes on November 27.

Jan 11, 1950

By L. Weaver

THE Tennessee Copper Co.'s mines are in the southeast corner of the state of Tennessee. Polk Co., in the well-known Ducktown copper basin. Their new circular production shaft will eventually be the only ore hoisting shaft, and is located for handling ore from Boyd, Calloway, Mary, and Cherokee mines. A circular, rather than a rectangular, shaft was decided upon because: 1-The circular shaft section is stronger when lined with concrete. Reinforcing steel was not required, thus reducing lining cost by one- quarter. 2-Water sealing was desired; it was thought it could best be done with a concrete lining followed by pressure grouting to eliminate water seeps. 3-The shaft labor saving equipment could best be used in a large opening, so the round section was made for economy, sinking, mucking, concreting and water sealing. Less shaft steel is used than could have been possible with steel sets. There are no posts required; center beams and Tee plate assembly placed at 10 ft hold the 100 lb steel guide rails. The shaft is 12 ft 7 1/2 in. ID of the concrete walls. This is large enough for two 10-ton hoisting skips and a ladder compartment. One of the skip compartments is for hauling equipment. The grouting equipment was a 2%xlO-in. Gardner-Denver grout pump, air powered and developing 1000 lb pressure. A grout mixer, also air driven, fed the mixed solution into a tank coupled to the pump suction. Grout materials used were mostly water and Portland cement. Some Bentonite was used to seal porous ground near the surface.

Jan 11, 1950

By John D. Clark

ONE'S lifetime does not usually offer the opportunity to observe and be a part of the commercial development of an entirely new material. Petalite has been known for over a century, but at first it was presumed rare. However, it was found to be so abundant that it has become a new and extremely useful industrial tool.

Jan 10, 1950

By C. H. Burgess

ON June 5, 1947, Secretary of State George C. Marshall in a speech at Harvard University outlined a plan for the economic recovery of Europe. The plan contemplated that the United States should provide assistance which would enable the European nations better to help themselves and to help each other to reconstitute from their war-torn lands conditions which would make possible decent standards of living. The Foreign Assistance Act of 1948 was passed in April of that year, and established the Eco-

Jan 10, 1950

By R. H. Eckhouse, M. R. Geer, H. F. Yancey, C. L. Allyn

Four coals were treated in the Humphreys spiral concentrator, and the products were examined by float-and-sink and screen-sizing tests to determine fundamental performance characteristics. The efficiency of the separation between coal and impurity was shown to be influenced greatly by particle size.

Jan 10, 1950

By S. H. Williston

IT IS not often that bore hole surveys can be checked by actual civil engineering methods. A recent Arizona survey was checked by normal surveying methods and the comparison of the results should be of value to both oil and mining men. During the summer of 1948 the Phelps-Dodge Corporation, at its Copper Queen property near Bisbee, Ariz., drilled a 1245 ft, 8 in. diam, churn drill-hole in a mineralized area and cased part of it, intending to use it to transfer mill tailings for stope fill. The hole, as frequently occurs, was not straight, and, in endeavoring to locate the bottom in the underground workings, they found no evidence of the hole at the underground coordinates directly below the surface location.

Jan 10, 1950

Taking the Long View THE present international situation has serious implications for this nation. The possibility of total war is no more appalling than the threat of making the United States permanently into an armed camp. A period of ten years under such conditions could mean a Communist victory without firing a shot-if the present trend toward statism is allowed to continue. As individual citizens and as members of the mining profession we have the power to oppose the march toward socialism. We must not adopt shortsighted policies dictated by self-interest, but must endeavor to size up the situation as a whole and act according to what will be best in the national interest. The economic picture for the metal mining industry under present emergency conditions is apparently bright. Demand for metals exceeds supply. But there is danger that fluctuating prices will bring Government regulation. Care must be exercised in our pricing policies, or the calamity of Government intervention will be inevitable. President Truman's "loophole" reference to percentage depletion early in the year caused a brief flurry of excitement, but now that the immediate threat is over the industry has lapsed into sommolence on this subject. Special tax privileges accorded the mining industry because of inherent risks should be guarded by a continuing propaganda campaign to educate Congress and the public. If this is not done we may find ourselves losing the necessary tax protection which we now possess by a capricious act of legislation. Stockpiling minerals from abroad certainly lengthens the life of our own mineral resources. The present consumer demand for the base metals indicates foreign sources of supply for stockpiling. However, this is only one facet of the problem. For strategic military reasons it is necessary that the United States have quick sources of all minerals within our national boundaries. Undeveloped mineral deposits do not meet this need so that where it is possible to encourage our own mineral development by stockpile purchases, it should be done. A need exists for an overall controlling agency that would make purchases for the stockpile according to military necessity, current metal market conditions, and so as to strengthen the mining industry. In the course of the history of the United States we have been engulfed in several wars by the necessity of protecting our economic rights abroad trading privileges-and also because of moral obligations. Disregarding the moral side, it is difficult to reconcile fighting wars to protect world freedom of trade when in peacetime we attempt to restrain such trade by tariff barriers. When it comes to accepting subsidies from the Government in one form or another it is difficult to overlook the immediate personal gains and see in the future that where the Government lays out capital it becomes a partner in the business and not a silent one. It is apparent that hope for the traditional American way of life cannot be bought without some self-sacrifice; and we cannot wait for the other fellow to start it because it is the responsibility of each individual citizen. By taking the long view our course should be apparent and not diverge sharply from our own personal benefit.

Jan 10, 1950

By S. F. Ravitz, S. R. Zimmerely

High-grade cobalt concentrates were produced from the complex Blackbird ore with very good recovery in continuous pilot-plant operations in which a low-grade bulk cobaltite-pyrite flotation concentrate was roasted in a multiple-hearth furnace to oxidize the pyrite selectively. The cobaltite was floated from the resulting calcine.

Jan 10, 1950

By Oliver C. Ralston, Foster Fraas

VIRTUALLY all commercial use of electrostatic separation has employed separators depending on differences of conductance of the broken, solid mixtures treated by them. The two main types of conductance separators have been: (1) Those in which the separating field is as near a static field between two charged electrodes as it is possible to maintain in the face of the usual leakage that takes place between electrodes with some 5 to 50 kv tension between them and spacing of l/z to 3 in.; (2) those in which a convective discharge of corona or spray type, but not a spark discharge, takes place between the carrier electrode and a charged electrode facing it, which is of very restricted area, such as a row of needle points or a small diameter wire parallel to the face of the carrier electrode. The present paper deals with this latter type. The principle is usable in separators where the carrier electrode, usually grounded, has the shape of a roller, a conveyor belt, a vibrating table, a sloping chute, or a nearly vertical plate. The innovation studied by us has been the use of the convective field for charging material on the carrier electrode and succeeded by a field between the carrier electrode and an electrode made of a true dielectric which cannot take on a charge by conduction but is charged by being in the radius of the corona discharge. The acquired charge is of the same sign as that of the corona but is not dischargable by contact with a good conductor. However, high-tension charge tends to leak off because of the ionization of the ambient air. The field between this electrode and the carrier electrode is as near static as it is possible to obtain. There are some differences in behavior of this electrode and that of the gas tube electrode used by Sutton, as will be discussed below. Both electrodes cause increased adhesion of nonconductive particles to the carrier roll. The particles are pinned there because they are convectively charged on their outer surfaces facing the corona electrode. The electrodes also cause increased rate of release of conductive particles tending to be pinned by corona charging but conveying the charge to the grounded carrier roll almost as rapidly as it is received by the particles.

Jan 10, 1950

By H. L. Teichman, E. M. Sipprelle

ENACTMENT of Public Law 290 by the 78th Congress authorized the U. S. Department of the Interior, Bureau of Mines, to conduct an experimental program to develop the technology for obtaining oil from oil shale. In adopting and later extending this legislation, the Congress recognized the impending necessity of supplementing ground petroleum reserves with synthetic fuels. Under the provisions of this legislation, the Bureau of Mines, among other things, was charged with the responsibility of developing mining techniques, methods, and equipment for mining the oil shales of the Green River formation of Colorado, Utah, and Wyoming.

Jan 10, 1950

ON the face of it, the American Mining Congress meeting was a big success, as witness the smiles on the AIME members, pictured here, who attended. The grins were captured at Booth 232, where caricaturist Lenn Redman held forth for the Independent Pneumatic Tool Co., sketching 114 subjects in one week.

Jan 10, 1950

• As part of $850,000 granted by the House Appropriations Committee for development of manganese in the U.S., the Bureau of Mines will build a pilot plant at Artillery Peak, Ariz., for development of low grade manganese ores. • The historic Argo tunnel and mill in Idaho Springs, Colo., will reopen shortly for the mining of uranium. The Uranium Co. of America has acquired control of the tunnel and mill and 12 nearby mining properties. J. H. Rodgers and G. C. Ridland will manage the operation. •The opening of a new 4000-ton per day coal mine in Washington Co., Pa., and the reopening of another mine of the same capacity in Fayette Co. has been announced by the H. C. Frick Coke Co. They'll help meet added war demands. •A 7000 bbl per day commercial synthetic liquid fuel plant, making gasoline from natural gas at Brownsville, Texas is being operated by the Carthage Hydro-col Corp., a Texaco subsidiary. The gasoline is produced by the Hydrocol process, chemically similar to the Fischer Tropsch process, but differing mechanically in several ways. To operate the process it has been necessary to build an oxygen plant producing 95 pct pure oxygen in quantities equal to U. S. production of commercial oxygen in 1946. •Over 96 pct of the class of 1950 at Montana School of Mines are now employed,, in industry, and they're scattered from MIT to the island of Cuba., • Cobalt, heretofore almost entirely imported, will soon be produced in Idaho. The Calera Mining Co. is building a 600-ton mill in which a cobalt and copper concentrate will be obtained from Idaho ores. •Plans for mining iron ore on the Conarky Peninsula in French Guinea, (an ECA project) call for equipment purchases as follows: 8 wagon drills, electric shovel for mining, conveyor for the port, 8 trucks, wrecker, 2 tractors, as well as miscellaneous accessories and spare parts. •A low-grade lead-zinc mineralization, located east of any known ore bodies in Utah's East Tintic district, has been located by a 2000-ft wildcat USGS drill hole. * Higher-than-going rates have been authorized by the Munitions Board for its stockpile program, where domestic production of scarce materials is low or uneconomical. Payment in excess of 25 pct over the foreign price is now permitted. •A new self-centering conveyor roll, developed by Carnegie-Illinois Steel, is expected to revolutionize materials handling. It completely eliminates the necessity for sideguides to keep materials on a conveyor. See P. 1028. •Great Britain's socialized coal industry employs twice as many miners, but produces less than half as much coal as America's coal industry. last year, British mines produced 28 million fewer tons of coal than the output of the same ,mines in 1939. Absenteeism amounted to a big 12 pot of working time. • Labor market conditions have tightened on almost a country-wide scale. Only 4 out of 143 major labor market areas have a substantial surplus -- less than half the total for May. Growing scarcities of skilled labor are in evidence.

Jan 10, 1950

By Russell Gibson, F. S. Turneaure

The tin deposit of Monserrat, Bolivia, consists of one major vein 1600 m in length. The ore is unusual because of the notable quantity of teallite, even though cassiterite is the principal tin mineral. The deposit, formed at shallow depth under a wide range in temperature, may be classed as xenothermal. Polished sections reveal a complex history of replacement, with low-temperature minerals deposited before high-temperature minerals.

Jan 10, 1950

By Garfield Schnee

MACHINERY has not taken the place of manual labor in steep pitch coal in the anthracite field and there is a shortage of miners experienced in this type of work. To overcome these difficulties several coal companies have resorted to different types of mining such as the diamond or zig-zag method, the slant method, long hole drilling, and several other variations. For the past 5 years the diamond shape method has been used extensively in the heavy pitching beds of both the Knickerbocker and Yatesville basins at Knickerbocker colliery of the Philadelphia & Reading Coal & Iron Co.

Jan 10, 1950

By A. A. Gustafson

The Freeport Sulphur Co. built a portable crusher in 1944 that solved a problem that none of the crusher manufacturing companies contacted were able to do. Two of these crushers have now been in service for 6 years, giving satisfactory service in handling a million tons per year, and having a capacity of over 2000 long tons per 8-hr shift. These machines reduce ton size blocks of sulphur to 12 in. and also feed the conveyor system at the rate of 350 long tons per hr per machine.

Jan 10, 1950

New Products Equipment

Jan 10, 1950

By E. P. McCurdy, William J. Tait, Allen E. Craig

The Circuitron herein described applies current from the classifier motor circuit and energy from the sound of grinding media to move an oscillating disc. The disc through a photoelectric cell controls the speed of the ore feeder and consequently the amount of ore delivered to the mill.

Jan 10, 1950

By L. E. Schiffman

This paper describes the operation of two kerosine flotation plants in Alabama for cleaning -10 mesh bituminous coal. One plant treats washer sludge, the other raw coal. Data on capacity efficiency and capital and operating costs is given. Methods for increasing cell capacity are discussed.

Jan 10, 1950