Determination of circulating load

There are several methods to estimate the circulating load in a grinding circuit. Probably the oldest method is to perform calculations based on the percent solids of different streams of the grinding circuit. The procedure needs to calculate the circulating load on the hydrocyclone.

Solids: F = feed, t/h; O = overflow, t/h and U = underflow, t/h

Dilution: f, feed; o, overflow; u, underflow

Circulating load = (o – f)/(f – u)

Next table is an example of the percent solid and dilution in a closed grinding circuit.

A complete mass balance is shown below,

Mass balance for a closed grinding circuit