Facts & Figures Book - KPI-JCI

Washin g/Classifyin gIn its strictest sense, however, classifying means thatseveral sizes of sand products of equal specific gravitycan be separated while rejecting slimes, silt and similardeleterious substances. But sand particles are notnecessarily always of the same specific gravity, so frequentlyboth specific gravity and particle size affect therate of settling. Consequently, you cannot always estimatethe probable gradation of the final products withoutpreliminary tests on the material. Nor can you be sure ofproduct quality without analysis and tests after processing.In any hydraulic classification of sand, the amount offines retained with the final product will be dependentupon:1. Area of settling basin2. Amount of water used3. Extent of turbulence in settling areaObviously, the area of the settling basin generally will befixed. Hence, the amount and size of fines to be rejectedwill be determined by regulating the water quantity andturbulence.108