Grinding, flotation and leaching circuits operate under specific ranges of solids percentage, which affect the pulp density and the rheology of the system under agitation. For this reason is importnat to know how to calculate it. The following formulas show some of the methods employed in the plants. If the level the automation high, the operator must be able compare the real results and those provided by electronic and sophisticated devices. Perhaps, try to control the pulp density is one of the most common tasks in operations, but try to get the optimum value is sometimes complex.
pd: pulp density; SG: solid specific gravity; S: percent solids; D: dilution
As an example, consider an ore with specific gravity of 2.8 and the hydrocyclone overflow must has a percent solids of 35%. In the operation, the operator can employ a Marcy Scale or watch the computer placed at the operator work station. If we replace the values in the formulas, pulp density takes a value of 1.29 and dilution a value of 1.86. In this way we can be sure if the values obtained in the scale and computer are correct or not. Next table shows pulp densities at different specific gravities and percent solids.
