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By Maurus Seet

Mainland China, with one-fourth of the world's population and one-tenth of its coal production, can no longer be ignored as a considerable force on the world energy scene. In terms of annual productivity, China's 300 million tons of coal rank third behind the Soviet Union with 655 million and the United States 557 million (1968 Minerals Yearbook. USBM). When viewed from another angle, 1967 figures show that increased productivity from all coal-producing continents, with the exception of North America, was led by Chinese-dominated Asia with a 19% gain. Not unpredictably though, China, on a per capita basis, is closer to the bottom of the list among members of the industrial community. Despite its misspent youth, and despite the set- backs caused by the Big Leap Forward of the late 50's and the Cultural Revolution of the late 60'S, the People's Republic has managed to make some impressive strides in developing its coal industry over the past twenty years.

Jan 1, 1971

By W. B. Mather

Arkansas' nonmetalliferous deposits are of many different types. The principal types briefly described in this paper are: clays, shales and slates; silica deposits; limestone and dolomite; barite; gypsum; celestite; nepheline syenite; greensand; phosphate; vermiculite; fuller's earth; bentonite; diamonds; sand and gravel. The future development of these deposits is expected to effect profoundly the industrial development of the state.

Jan 5, 1950

Jan 1, 1900

By S. S. Clarke

THE opening of sheet-ground mines in which the ore beds are only from 7 to 9 ft. thick led the Commerce Mining and Royalty Co. to con-sider mechanical loading, in order to avoid the high cost of hand shovel-ing in such mines. Scraper loaders were chosen because the capital investment would be comparatively low; because they are small enough to be used in low working faces, and because they can be mounted on a mobile carrier.

Jan 1, 1939

Jan 1, 1909

By E. M. MacKevett

The only source of uranium ore in Alaska that has been mined commercially is the Ross-Adams de- posit, a gently inclined, fusiform orebody in alkali granite in which uranothorite and uranoan thorianlte are the chief ore minerals. In mode of occurrence, apparent genetic association with the granite, and to a lesser extent in mineralogy, this type of deposit is uncommon. The mine is in the southern part of Prince of Wales Island (Fig. 1) at an altitude of about 950 ft on the southeast flank of Bokan Mountain. A steep unpaved road 1 ¾ miles long leads to the dock on the West Arm of Kendrick Bay, which can be reached by boat or seaplane from Ketchikan, some 35 miles to the northeast.

Jan 9, 1959

By Francis Freeland

An examination of accessible English literature shows that but small space has been allotted to the determination of faults ; most suggestions being confined to Schmidt's rule of the downthrow on the hanging-wall of the fault, or the coal-miner's rule of the obtuse angle. Von Carnall's modification of Schmidt's rule is sometimes given without the important exception, and Zimmermann's rule is

Jan 1, 1893

By Fritz F. Prugger, Peter R. Jones

This paper considers some of the main aspects of underground mining in the flat, rich, but deep lying deposits of Saskatchewan. It briefly describes the pertinent geological features as they relate to mining and the practical de-stressing techniques used to allow productive extraction in the high stress environment present in many of the province’s mines. Mining layouts, materials handling, and the evolution of some of the world's largest mining equipment are examined.

Jan 1, 1983

By Ali M. Heidarieh Zadeh, Raghu N. Singh

The paper presents a stability investigation of shaft intersections and pit bottom roadways in the vicinity of upcast and downcast shafts at a colliery in the U.K. Aschemeof instrumentation was aimed at monitoring the strata displacement surrounding the pit bottom roadways and shaft intersections with a view to ascertaining the origin of the strata movement and effectiveness of the control measures. The bore- hole instrumentation results together with a theoretical analysis suggested that the cause of instability could be attributed to the drivage of a roadway within the shaft pillar. A semi-empirical technique was used to calculate the amount of support resistance required to reinforce the pillar to take additional abutment load. A rock bolting system was designed to provide a required increase in thrust capacity of the roadway support. The results indicated that roadway closure was effectively controlled after installation of bolts indicating efficacy of the control measures adopted.

Jan 1, 1982

By B. I. Routh

A STUDY of the effects of temperature on the gel strength of drilling muds is a natural outgrowth of the present era of deep drilling. The control of the gel solids' is now considered important because it affects the wall-building qualities; the suspension of weighting material; the removal and release of sand, cuttings, and gas; and the control of cav-ing formations. With regard to the effect of temperature on gel strengths Herrick2 states: "Temperature variation within ordinary limits does not have much effect on yield points." Lewis, Squires and Thompson3 investi-gated one clay and found no marked change with temperature in either yield point or mobility. Reed4 found that potassium bentonite showed a great increase of gelation with increase in temperature and qualitatively there occurred a marked increase in viscosity upon heating. The apparatus used in these experiments consisted of a Stormer viscosimeter, Marsh funnel viscosimeter, rectangular and cylindrical shearometers, Mudwate hydrometer, and other minor laboratory equip-ment. The various methods of measuring viscosity and gel strength have been extensively described by Evans and Reid.5

Jan 1, 1938

By Arthur F. L. Bell

Discussion of the paper of ARTHUR F. L. BELL, presented at the San Francisco meeting, September, 1915, and printed in Bulletin No. 105, September, 1915, pp. 1769 to 1799. WILLIAM A. WILLIAMS, San Francisco, Cal.-Is the Union Avila plant run as a topping plant or as a dehydrating plant? A. F. L. BELL, San Francisco, Cal.-Both. It takes off an average of 20 per cent. water besides topping the oil. Part of the crude oil is run through an electrical separator before running to the topping plant, but the entire crude averages about 20 per cent. when it enters the topping plant. DAVID T. DAY, Washington, D. C.-I suppose most of the work contemplated in these large topping plants is simply to deal with topping the oils with only a small percentage of water in them. A. F. L. BELL.-Not more than 2 per cent. of water can be handled in ordinary stills without causing trouble. At our Gavotte refinery, where the oil runs from 15 to 30 per cent. water, we carry 20 lb., pressure oil our stills to hold the framing down, we can do that with small stills, with large one's it would not be safe; but with a retort, the quantity of water contained in the oil does not affect its working. It simply means additional fuel to evaporate the water.

Jan 12, 1915

Jan 1, 1924

COUNCIL OF SECTION DELEGATES E H Stevens, Chairman James W Halley, Vice-Chairman George J Donaldson, Secretary The Peoples Natural Gas Co 140 Stanwix St Pittsburgh 22, Pa EXECUTIVE COMMITTEE H R Wardwell, J G Evans, H R Bianco, Harry Campbell

Jan 1, 1955

By R. V. Norris

In a former paper on this subject,' I summarized Murgue's theory and experiments, and presented a large number of tests of mine-fans, stating some conclusions, " more or less warranted by the evidence," as to design, capacity and efficiency. Since that time the very valuable report of Mr. M. Walton Brown: Committee on Mechanical Ventikators, Institution of Mining Engineers, has appeared, and I have made additional experiments which tend to clear up some points in connection with this subject. Design and Tests of the Luke-Fidlbr Colliery Fan. The Luke-Fidler fan (see Figs. 1, 2 and 3), built to replace an old wooden fan at a very fiery colliery, presents some pecu-

Jan 1, 1905

By Marius R. Campbell

VArIoUs classes of coals are recognized in this country at the present time. These classes depend largely upon physical characteristics rather than upon chemical composition, and consequently they cannot be accurately defined. The divisions into anthracite, semi-anthracite and semi-bituminons are fairly satisfactory; but the term bituminous embraces so large a variety of coal that it is of little value, and the term lignite is so loosely applied that it has little or no place in a scientific classification.

Jan 1, 1906

Jan 1, 1934

ALLERTON S. CUSHMAN, Middletown, Ohio (written discussion*).¬ This subject is one to which I have given much thought and study and which I have frequently discussed informally with Mr. Cain and others. I have long been convinced that the gaseous elements, either combined or entrained (occluded), in steel play a much more important role than is ordinarily admitted. This is probably due to the difficulties encountered in the accurate quantitative estimation of gases, some of which Mr. Cain has referred to, as well as to the fact that, considered from the weight-percentage basis, gas content is measurable only in hundredths or even thousandths of 1 per cent. Volumetrically, however, the results ob-tained by modern research are startling, to say the least. Baraduc-Muller,1 as cited by Mr. Cain, pumped out of 1000-lb. ingots of basic Bessemer steel 2100 l. of gas. or about 75 cu. ft., at normal temperature and pressure, per ton of steel. In other words, we are to understand that Bessemer steel normally carries about fifteen times its own volume of gas. According to Baraduc-Müller's table of results, which is given here-with, carbon monoxide, nitrogen, and hydrogen are important consti-tuents of Bessemer steel, the latter gas being undoubtedly formed by the

Jan 11, 1919

By Harry A. Roe

The power drag scrapers and the slackline cableway excavator have been called "long-range excavators." Broadly, their field of usefulness is restricted to work in which their long range of action permits them to operate economically, and which other, possibly more conventional, excavating units cannot do. Both of these machines dig or lift material and transport it to a remote dumping point. They combine these two functions in a single machine, nearly always in a single straight-line motion. The purpose of this paper is to examine the important features that distinguish the machines in this group from each other, as well as from other groups. The Machines The "power drag scraper" is a long-range excavating machine that employs a bottomless drag scraper operated back and forth between digging and dumping points by two haulage cables. The typical arrangement is that of Fig. 1. This is the "slusher" of the underground mine, as well as the "dragline scraper" of the sand and gravel industry, and other open-pit mining operations.

Jan 1, 1938

By H. S. Drinker

THE first discovery of zinc 011 the property now worked by this company was made by the celebrated mineralogist, Prof. William Theodore Rapper, in 1845. Different claimants kept the property in continual litigation till 1861, when everything was satisfactorily settled by the purchase of the land by the company, who have worked it ever since. The mines are situated in a valley, four miles south of Bethlehem, Pa., in Lehigh County. The valley is from two to three miles broad, and is bounded 011 the north and south by syenitic hills. Syenite underlies the valley, and upon this is deposited the Potsdam sandstone, then a layer of slate, and, finally, a dolomitic limestone, belonging to the Chazy or Black River formation, in which the zinc deposits are inclosed. The rocks occur in folds, and have evidently been subjected to tremendous pressure from below, the zinc deposit being found in an anticlinal axis, in nearly vertical veins. I t is supposed that the zinc was originally disseminated through the

By Thomas W. Healy

Particles present in mineral processing systems that are termed ultrafine are those that are small enough to be unaffected by gravity or the flow conditions imposed on the pulp. As such, their interaction with one another and with other larger particles are controlled by specific attractive and repulsive colloidal or surface interactions. Electrostatic repulsion between ultrafines is dominated by surface potential, double layer thickness and specific adsorption potential effects - controlled by pH, salt and complexing ion concentrations. Attraction due to van der Waals interactions must be assessed in terms of bulk and surface coating effects and of particle size and shape. The net effect of attraction and repulsion must finally be related to the average kinetic energy of particles in the real system.

Jan 1, 1979