53 ° U . S . BUREAU OF MINES NOTES. [J. F. [.

OIL-SHALE E X P E R I M E N T A L PLANT N E A R RULISON, COLORADO.

By M. J. Gavin.

INVESTIGATIONS Of the treatment of oil shales conducted by the Bureau of Mines over a period of ten years, in co61)eration with the states of Utah and Colorado, and work of other agencies, has aroused much interest in these shales as a commercial source of oil. At the suggestion of the committee appointed by the President to determine the possibilities of a future supply of oil for the Navy, Congress appropriated $90,o00 to the Bureau of Mines in March, I925, for the construction and operation of a pilot oil-shale plant and the purchase and mining of shale. The site selected for the plant is I ~ miles southwest of Rulison, in Garfield County, Colo., on Naval oil-shale reserve No. .3 . A 3-mile trail from the plant site to the mine site and a road from Rulison to the plant were constructed by the county road board. An aerial tram line is being erected from the mine to the plant, along a route based on topographical survey made by the United States Geological Survey. The General Land Office co45perated by making a survey for the water supply line to the plant. The town of Rifle, 13 miles from the plant, has donated the use of an office in its high school building. Several plant buildings have been constructed, and the work of installing equipment is practically completed. The plant includes a Pumpherston oil-shale retort purchased in Scotland, an American type retort, scrubbers, condensers, gas producer, water tank, boilers, crushers, a labora- tory, and other equipment. The Scotch type of retort was recently placed in operation and the American type retort will probably be started in the latter part of September.

MINE D R A I N A G E IN IRON MINES OF ALABAMA. By W. R. Crane.

AN INVESTIGATION Of drainage problems in the red iron ore mines of the Birmingham district in Alabama has been completed. The work comprised a detailed study of rainfatl, run-off, source of surface and ground waters, and their entry into the mines. The effects of ground movement and subsidence on the drainage of the surface overlying the mines was also studied. Data were obtained on the relations between all phases of the movement of water on the surface and underground, and the effects of mining

Oct., 1926.] U . S . BUREAU OF MINES NOTES. 531

on the natural drainage conditions. With these data in hand, the operators can attack their drainage problems more intelligently and plan more effectively the measures needed to take care of troublesome water.

COAL-ASH F U S I B I L I T Y AS R E L A T E D TO C L I N K E R F O R M A T I O N .

By A. C. Fi¢ldner.

THE Bureau of Mines is conducting, at the Pittsburgh experi- ment station, tests of the fusibility of coal ash and the relation of such tests to the clinkering characteristics of the coal. While laboratory methods for determining fusibility of ash have been carefully investigated by the bureau and standardized, no compre- hensive study has hitherto been made as to how accurately such laboratory tests predict clinker trouble in burning coal. Seven different coals having a wide range of ash fusibility were tested for fusibility by the standard method worked out by the bureau, and by two other well-known methods. The coals were studied as to the distribution and composition of the ash-forming constitu- ents, the sulphur content, and fusibility of ash. Firing tests were made on the same coals in a specia'l hand-fired furnace developed by the bureau engineers. The results of the fusibility tests were found to be indicative of the clinkering trouble that was experi- enced in burning the coals. The work is being continued on other coa'ls.

S P O N T A N E O U S C O M B U S T I O N OF COAL. By J. D. Davis.

LABORATORY studies of the heating characteristics of coal under controlled conditions have been completed. The amount of heat involved in the early stages of initial heating was accurately determined, and fundamental data were obtained on the sensitivi- ties of various coals, and the effects of different physical factors, such as ventilation, flow of heat, and presence of moisture, on the tendency to spontaneous heating. It was found that in co~l at normal room temperature (7o°F.) , the heating action, if any, was too slight to be detected by the most sensitive methods, but from temperatures comparable with a hot day in summer ( Ioo°F . ) spontaneous heating could be developed with dry coal to the ig-ni- tion point without external heat being applied, provided adiabatic

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