WHOLE CROP PROCESSING AT BROADWATER MILL: IMPACTS ON PROCESS OPERATIONS

DURING THE processing of the whole cane crop (comprising typically 20% of the total mass as tops and leaves) at Broadwater Mill during the 2009 season the presence of specific impurities and increased quantities of soluble impurities in the mixed juice adversely affected several process stations of the factory. The clarification and filtration stations experienced increased mud solids loadings and reduced efficiency in clarification, and the production rates at both the pan and fugal stations were substantially reduced. Quantifiable changes in evaporator station capacity due to changes in scaling rates were not experienced but this may have been a consequence of the short duration of the whole crop trials (two weeks). The sugar production was characterised by increased colour and ash. Investigations were undertaken at each of the process stations to quantify the impact of whole crop processing and to measure changes to fundamental parameters so that the causes of the reduced efficiencies could be differentiated. These results have been used to define procedures to mitigate the impacts of crushing the whole crop on factory processing operations.