Experience with magma preparation for continuous high-grade seed duty at Victoria mill

This paper covers recent trials conducted on the Victoria Mill high-grade vertical seed pan, the first installation for this duty in Australia. It supplies high-grade seed for standard batch dropping pans. The Victoria seed operation is magma-based (unlike the Plane Creek operation which is high-grade grain based), i.e., it uses low-grade crystal as starting nuclei. The main problem associated with this method is the need for magma preparation. The pan was installed in 1994 and after an initial bedding-in period, an inline magma preparation process was adopted from batch practice. Essentially, the magma is washed in the first module of this three-module pan. Results from this continuous magma preparation process were very good. This paper describes the results obtained for both the continuous magma preparation method and the most recent experience with direct magma addition, which uses no dilution/washing preparation. Trial results indicate that direct magma addition is a viable alternative with the CSR pan design. There are major implications for equipment investment at CSR Victoria Mill and throughout the CSR Sugar Mills Group.