Comminution – Circuit Optimisation
OMC optimise and audit comminution circuits worldwide. This process can involve a site visit to analyse circuit performance through a review of production data, control philosophy and undertaking plant trials. A modelling study using survey data is then undertaken. Alternatively, a modelling study alone can be conducted with client supplied data, however the combination of a site visit and a modelling study has been found to achieve the best results.
A comminution circuit optimisation typically involves a circuit audit and collection of crushing and grinding circuit survey data. This includes an inventory of major equipment sizes and operating conditions. Mass flows, particle size distributions and densities for each stream are collected along with samples for ore characterisation testwork.
Considerable improvements in plant performance can often be obtained through recommended changes to the operating/control philosophy and training of plant staff based on the site visit findings and preliminary audit results.
Once the testwork is completed, recommendations are then made based upon analysis of the data and the specific problem areas identified. These changes may include:
- Mill feed size
- Control strategy
- Pulp density
- Recycle crushing
- Cyclone configuration and operation
- Throughput
- Ball load level and diameter
- Discharge grate configuration
- Circulating load
- Mill load level
- Mill speed
Survey data is model fitted using a combination of OMC’s power based and JK SimMet modelling techniques. Simulations are then undertaken to assess the influence of varying process parameters on the circuit performance, with the optimal parameters selected.
- OMC power models are used to model the operation of each mill and to assess the power efficiency of the circuit during the survey.
- JK SimMet is used to simulate the circuit performance from a breakage rate, size distribution and density perspective to assess the significance of proposed plant improvements.
