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Jan 1, 1949

By J. D. Cooner

SINCE my working life of 32 yr has been spent in and about the anthracite mines of the Hudson Coal Co., and the previous 4 yr in a college school of mines, I can write best about the safety program of a coal mining company. However, most of the suggestions, statements and practices mentioned herein are applicable to the members of a safety organization and program of almost any industry. It is realized that industrial officials actually interested in real safety work are fully acquainted with the requirements of a practical safety program. Therefore, for such persons there may be nothing new in this paper. The Hudson Coal Co. of Scranton, Pa., employs 7,000 men and produces 5,000,000 tons of anthracite annually at nine collieries scattered for a distance of 40 miles throughout the Lackawanna and Wyoming valleys of northeastern Pennsylvania. For the past 17 yr of the above mentioned 32, I have been engaged in safety work as a safety inspector, assistant mine superintendent, and at present the safety engineer. I have also had the privilege of visiting coal and metal mines in other parts of the United States and Canada. We Americans are the most careless people in the world. If any one doubts this statement why are 100,000 of our people killed accidentally annually? Or why during the almost four years we were engaged in World War II were more of our people killed accidentally at home than were killed in our army, navy, marine corps, coast guard, and other services during the same period? We are careless everywhere in our homes, on the highway, at work and at play. The purpose of this paper is to outline the requisites of a safety department and its program to stop the accidents occurring to employees at work in mines or industrial plants. The first requisite for a safety program is that the management must be convinced of the need and value of a real safety program. By "management" is meant each department head from the president down. Otherwise a good safety department with a good safety program will not succeed because it will not have the proper personnel and equipment to work with, its rules and regulations will not be enforced, and the members of the safety department will be belittled in the eyes of most of the workmen and supervisors. Next, a safety engineer and his inspectors should have worked in the production end of the mines as workmen and also in an official capacity. They are then in a position to have practical and first hand knowledge of the accident hazards of the industry, how to prevent them, and in general the problems of both the workmen and officials. Some men are appointed as safety inspectors when they are physically unable to carry on as mine officials. Such men may know the safety end of the industry and even be safety-conscious, but if they are physically unable to be mine officials they are also physically unable to be safety inspectors, as a safety inspector in our mines must walk from 2 to 4 miles on each daily inspection-and visit each working

Jan 1, 1948

Jan 1, 1949

Mining Methods GERALD F. SHERMAN, Chairman JOHN A. CHURCH, Vice-chaiman CHARLES W. WRIGHT, Secretary Alluvial Mining CLINTON BERNARD CHARLES JANIN H.R. NORSWORTHY Open-cut Mining Iron MAX H. BARBER J. A. MACKILLICAN Copper MICHAEL CURLEY R.B. TEMPEST Underground Mining Iron C. H. BAXTER TENNEY C. DESOLLAR

Jan 1, 1934

Jan 1, 1943

Jan 1, 1943

The current status of the US lead and zinc industries was reviewed by J. G. McCullough, president of Amax Lead and Zinc Inc. He reported that in the US, lead and zinc are separate industries because of the nature of mineralization. The large Mississippi-type zinc deposits are practically lead-free, and while the new lead belt in Missouri has some zinc content, it does not have the same favorable economic impact as in the complex massive sulfide ore bodies being developed elsewhere.

Jan 11, 1977

J. E. Stead, Middlesborough, England (communication to the author): Prof. Howe's valuable paper on cast-iron brings forward most prominently the correct explanation of the part played by combined carbon in pearlite and cementite, in determining the strength and hardness of cast-iron. On a previous occasioil I have shown that castings made by melting a white Cleveland iron and glazed iron, one containing 1.5 and the other from 4 to 5 per cent. of silicon, and each about 3 per cent. of carbon, were stronger than those made of ordinary foundry-iron; the difference in the final castings being a differ-

Jan 1, 1902

By Ralph H. Sweetser

To control the slag in an iron blast furnace is to control the quality of the pig iron produced (and to a certain extent the tonnage), and to control the whole operation of the furnace itself, including a large part of the cost of production. The character of the slag is the determining factor in the character of the pig iron as to the controllable limits of sulfur, silicon, and, to a certain extent, the manganese; it has an influence on the proportions of combined and graphitic carbons.

Jan 1, 1935

By N. D. Policow, J. S. Orphanos

Dewatering fine clean coal fractions, -595µm (-28 mesh), represents one of the most difficult and costly separations in typical plant circuits. Since 1969, the screen bowl centrifuge has offered an economical alternative to filtration/thermal dyer combinations. The performance of screen bowl centrifuges has been continuously modified and improved to dewater not only coarser coals, but also today's variety of ultrafine material. Test comparisons with alternative methods show the screen bowl centrifuge to be most cost effective and efficient when all factors are considered.

Jan 1, 1984

By Ralph H. Sweetser

To control the slag in an iron blast furnace is to control the quality of the pig iron produced (and to a certain extent the tonnage), and to control the whole operation of the furnace itself, including a large part of the cost of production. The character of the slag is the determining factor in the character of the pig iron as to the controllable limits of sulfur, silicon, and, to a certain extent, the manganese; it has an influence on the proportions of combined and graphitic carbons.

Jan 1, 1935

Jan 1, 1959

By T. Egleston

THERE has always been a-theory among those working placer mines that gold is both found " rusty," and becomes so under treatment, by which they mean, not that gold becomes coated with oxide of gold, bat that it is either coated superficially or alloyed with sortie substanee 'which prevents the ,contact with mercury, and thus precludes the possibility of amalgamation. To such conditions of the

Jan 1, 1881

By Kenneth L. Zonge

Recently, extensive field use has been made of a digital minicomputer incorporated into a modified geophysical prospecting method. This is a generalized induced polarization (IP) system called complex resistivity (CR) and has been successfully used in sulfide mineral exploration. The ease of use, portability and cost effectiveness of this computer-controlled method has provided a viable exploration tool based on a complex data acquisition system. Without the computer, this method would still be relegated to tedious laboratory measurements and theoretical studies.

Jan 1, 1976

By W. E. Curran

For years the geographical isolation of the Southern iron-ore district from the great producing centers in the North and East enabled it to meet its conditions and solve its own problems without regard to the practices and policies of other districts, but during the past few years distances have been shortened, practices and wages are being standardized, .and these changing conditions have brought new problems to the South.

Jan 1, 1937

By Horace Pops, J. F. Libsch

THE discovery of SAP alloys (sintered aluminum powders) by lrmannl has stimulated investigations in other alloy systems.23 Not only do such alloys have good room-temperature properties, but they maintain high strength after prolonged service at elevated temperatures. In addition, they show high structural stability, including unusually high recrystallization temperatures. These characteristics are secured by dispersion hardening. For this investigation, Zn-ZnO alloys were selected. Practically, the fact that commercially pure zinc recrystallizes near room temperature prohibits strengthening and hardening by cold deformation and therefore limits the application of zinc where mechanical strength is important. Similarly, the poor

Jan 1, 1961

By Joseph A. Newman

THE first trial of longhole drilling of raises began in June 1949 at the Holden mine, Chelan Div., Howe Sound Co. The cost of this raise was about the same as the average cost of raising by normal methods which was sufficiently encouraging to give the method further trial. At Holden, the Noranda method of blasthole drilling is used except that percussion drills have replaced diamond drills for making blastholes in all but certain special situations. Two thirds of these holes are between 40 and 70 ft long.

Jan 10, 1951

By Wheeler P. Davey

In an article in the General Electric Review, January, 1915, reference was made to the X-ray examination of a steel casting 9/16 in thick. Fig. 1 shows one of the radiographs thus obtained. All these radiographs showed plainly the tool marks on the surface of the casting. All but one showed peculiar markings the shape of which strongly suggested that they were indeed the pictures of holes in the interior. A circular piece, 1 in. in diameter, was punched from the casting at a point where the radiograph shown in Fig. 1 indicated that a blow-hole should be found. (Location of sample shown by circle in Fig. l.) Fig. 2 is a photograph of the end of the punching, showing the hole that was found. Since that article was written it has seemed desirable: (1) to obtain data from which the exposure necessary for any thickness of steel could be at once calculated; (2) to find the thickness of the smallest air inclusion which could be radiographed in a given thickness of steel; (3) to determine in what direction to hope for further progress; and (4) to develop the technique of radiographing metals. In order to gain some preliminary data, several pieces of 1/2-in. (12.5-mm.) boiler plate were obtained, 5 by 7 in. (12.5 by 17.5 cm.) in size. In one of these, holes were drilled in such a way that the axis of each hole was midway between the faces of the steel and parallel to those faces. The diameters of these holes were as follows: Hole number Diameter I.........................................1/4 in. =6.3 mm 2........................................1/8 in. =3.l mm. 3................................... 1/16 in. = 1.6mm. 4....................................... 1/32 in. = 0.8 mm. 5........................................1/64 in. = 0.4 mm. Exposures were made on Seed X-ray plates at 20 in. (50 cm.) distance with Coolidge tube X-117, operated on Scheidel-Western induction coil with mercury turbine break. The X-ray plate was placed on a sheet of 1/8in. (3.1-mm.) lead. The steel was placed above this and a Iead

Jan 1, 1916

By J. S. Hromatko, L. J. Gurevich

In the course of the examination, at the BureLu of Standards, of fusible tin boiler plugs for the Steamboat Inspection Service, it became evident that an investigation should be undcrtaken to determine the precautions necessary in the manufacture of acceptable plugs. The results of the tests of these plugs show that their manufacture has improved, though at present not all of the plugs tested are, satisfactory. Table 1 gives the result of tests of some 1500 plugs from about 100 makers. Records of the tests show that several of the makers were able to produce satisfactory plugs with every pouring. The Steamboat Inspection Service has the following specifications for fusible plugs: "Fusible plugs for use in boilers of steam vessels under the jurisdiction of the Steamboat Inspection Service shall be made of bronze casing with the bore tapering continuously and openly from end to end, and filled from end to end with tin not less than 99.7 per cent. pure and to contain not more than 0.1 per cent. of lead and not more than 0.1 per cent. of zinc. The small end of the bore may be countersunk not more than 1/32 in. in depth and width, but no recess, thread, or cavity other than this countersink shall be allowed." Table 1.—Thirty-"five-mdh Testing Record of Fusible Plugs Causes of Rejection Inspection Period June-November, 1916.................. 311 32.8 47.2 3.8 11.5 15. 1 10.9 1 1.9 4.5 December, 1916-May, 1917............. 318 71.4 28.6 2.2 4.4 12.8 5.9 i ... 2.8 June-November, 1917.................. 228 73.0 27.01 ... 9.6, 5.2 9.6' ... 0.8 December, 1917-May. 1918............. 214 72.028.0 0.9 0.4 11.6 7.0 ... 7.9 June-November, 1918...............250 70.7 29.3 ... 2.0 20.0 5.2 ....2.8 December, 1918-April. 1919............ 23378.121.9 7.2 1.2 1 4.7 3.0 ... 6.0 Total 35 months....................1544.69.7 30.3 2.3 4.8 11 0 6.9 0.3 4.1

Jan 1, 1921

By T. F. Adams, L. G. Margolin

The Bedded Crack Model (BCM) is a constitutive model for brittle materials. It is based on effective modulus theory and makes use of a generalized Griffith criterion for crack growth. It is used in a solid dynamic computer code to simulate stress wave propagation and fracture in rock. A general description of the model is given and then the theoretical basis for it is presented. Some effects of finite cell size in numerical simulations are discussed. The use of the BCM is illustrated in simulations of explosive fracture of oil shale. There is generally good agreement between the calculations and data from field experiments.

Jan 1, 1982