A typical mineral processing plant consists of two major sections: a dry circuit and a wet circuit. As the name implies, a dry circuit does not require water to process ore, and its main purpose is to reduce the ore size until it can be further processed in milling and flotation circuits that form the wet circuit. Dry circuits may vary in terms of arrangement and configuration, but their main purpose remains the same: the gradual reduction of the ore along the circuit.
Dry circuits are often split into several sub-circuits (or unit operations), such as primary, secondary, and tertiary crushing. They are typically separated by large storage buffers, such as stockpiles and silos, which allow independent operation of the sub-circuits; for instance, maintenance can be performed on the secondary circuit while the tertiary circuit still produces the crushed product material.
An example of a dry circuit is shown in Figure 1. Most often, each sub-circuit has its own control layer, mainly consisting of base regulatory control, which controls each piece of equipment separately. In some cases, an advanced process control (APC) layer links the regulatory controllers into one system.