Preliminary study on the potential of improving pulp quality and energy efficiency in a South African TMP mill

Abstract

Under the current mill refining practices, the mill is introducing too much refining energy into the fibre. The lower levels of freeness for the accept samples (18 vs. 90 CSF ml required) and the higher amounts of fines confirms this (Table 1& Fig 4). The mill’s screen fractionation process has limited efficiency. Substantial amounts of thick-walled fibres are present in the mill accept pulp samples (i.e. 66% by mass of the mill accept has a freeness of 256 ml CSF (Table 2)). The benefits of adding a Hydrocyclone to the fractionating system for TMP pulp has been demonstrated. The information revealed in the study may be used as benchmark for evaluating alternative ways of optimising the TMP process. One approach could be a single stage refining followed by a screen and Hydrocyclone fractionation.