Sensitivity analysis of Austin's scale-up model for tumbling ball mills - Part 2. Effects of full-scale milling parameters

- The sensitivity of Austin's scale-up model for batch milling data was tested.
- Seventeen parameters descriptive of the full-scale operation were simulated.
- Scale-up correction factors were found to incur the highest discrepancies.
- Mill diameter, top-up ball size, in-mill flow pattern also affect the product greatly.

The need for scale-up of laboratory milling data to full operation is critical especially for the proper selection of design parameters. This paper investigates the extent to which full-scale milling conditions and design parameters influence the discharged product.Austin's scale-up procedure for batch grinding data is used to this end and is applied to a continuous mill operated in open circuit. The circuit was simulated in steady-state regime using randomly generated parameters within predefined ranges. These enabled the iterative computation of the corresponding mill products, average characteristic sizes and standard deviations.Simulation outcomes suggest that mill diameter, top-up ball diameter, in-mill flow pattern, and two scale-up correction factors in Austin's model have a greater bearing on mill product. The two correction factors account for the change in mill diameter and ball size from batch to full-scale milling respectively.

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