| Description |
iv, 51 leaves : illustrations ; 29 cm |
| Summary |
"In the dry grinding of cement clinker to a fine powder in which for example ninety percent or more of the particles are reduced to a fineness below that of a 200 mesh screen, it has been found that further fine grinding is extremely difficult and the energy input is out of all proportion to the further production of fine particles. This seems to be due to the fact that when the bulk of the material reaches this fineness there is a tendency of the finest particles to cling to each other and bunch or flocculate. Along with this tendency is an adhereing to the balls and the sides of the mill, thus producing a cushioning effect as the balls come into contact with the material being ground. This coating adheres tightly to the balls and increases in thickness as the grinding progresses. What is a grinding aid? A grinding aid might be thought of as a small amount of a foreign substance which is added to the material to be ground so as to facilitate the grinding operation. This is done by counteracting the tendency of the fine particles to flocculate and coat the balls and mill"--Introduction, leaf 1. |
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