Bulletin . roper lubrication of the mold thecone can be ejected immediatelyafter molding without waiting forthe cone to dry; a slight round-ing of the bottom groove of the mold greatly facilitates removal ofthe cone. After the cones had dried, they were mounted in a refractory basecomposed of a mixture of equal parts of kaolin and alumina (A1203).This mixture was moistened with water to make it workable, andenough was taken for the base to be made and was spread on a sheet-iron plate. A small hole was made, into which the cone was set,and the base material was worked around the bottom of the c
Bulletin . roper lubrication of the mold thecone can be ejected immediatelyafter molding without waiting forthe cone to dry; a slight round-ing of the bottom groove of the mold greatly facilitates removal ofthe cone. After the cones had dried, they were mounted in a refractory basecomposed of a mixture of equal parts of kaolin and alumina (A1203).This mixture was moistened with water to make it workable, andenough was taken for the base to be made and was spread on a sheet-iron plate. A small hole was made, into which the cone was set,and the base material was worked around the bottom of the cone sothat it would be firmly set at the desired inclination in the base. Theiron plate was then put on a hot plate, and the mounted cones weredried slowly until all water had been driven off. After the dextrinhad been burned by igniting the mounted cones in a muffle, they wereready for use. In the earlier experiments the cones were made di-rectlv from the 100-mesh ash; later it was found that ash ground to. Figure 7.—Brass cone mold. Stanton, F. and Fieldner, A. C, Methods of analyzing coal and coke: a, Bureau of Mines, 1913, pp. 7-9. 30 FUSIBILITY OF COAL ASH. an impalpable powder (or at least to pass a 200-mesh screen) made amore substantial and more easily molded cone than 100-mesh mater-ial. Four different sizes of cones were used, as follows: Sizes of cones. No. 1—Side of base, \ inch; height, 1 2—Side of base, \ inch; height, 1$ 3—Side of base, A inch; height, 1 4—Side of base, A inch; height, 2\ inches. GENERAL METHOD OF HEATING. The general procedure in making a softening-temperature de-termination was the same with all the furnaces used, though neces-sarily the details varied in the different furnaces. The test cone wasput into the cold or nearly cold furnace and the furnace was heatedat the rate of 10° to 15° C. per minute up to a temperature not lessthan 200° C. below the probable softening point, when the rat
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectminesandmineralresou
