New method for measuring pitch and stickies deposition potential and treatment efficacy

Hydro Pulsed Colloidal Deposition (HPCD) allows the lab-scale study of pitch and stickies deposition in pulp suspensions. It is generally assumed that deposition mechanisms involve an invisible thin organic layer on which the visible detectable deposit begins to build-up. However, this thin organic layer has never been detected or reported. In HPCD, spectrophotometric techniques are used to detect this organic layer, and the data obtained shows that there are several different mechanisms by which a deposit can be formed. Consequently, different chemical control mechanisms can be evaluated in the lab, to determine the most appropriate deposition control strategy for a given mill. The current lab evaluations concentrate on stickies stabilization effects with other chemistries as a means of chemically controlling deposition. Studies have also been conducted on pulp ageing phenomena with respect to depositability properties. Mill data showing the translation of these lab results to a recycling mill using the system for on-machine control show a reduction in downtime for wire cleaning.