Control of Contaminants in the Pulp Mill, 1994 Pulping Conference Proceedings

G.D. Laubach

Today, pulp mills face continued pressure to produce cleaner, stronger pulp while maintaining higher production rates and utilizing the most economical wood source. These goals, combined with economic and environmental mandates resulting in increased mill water closure and release restrictions, place further pressures on the pulp mill to maintain a clean and continuous running system.

Increased productivity often means an overloaded system. Along with more wood fiber comes an increased level of contaminants, both organic and inorganic. These contaminants, such as bark, pitch, calcium, magnesium, will interfere with the runnability of a pulping operation. With increased mill closure the concentration of contaminants increases, thereby increasing the tendency for deposits. These deposits reduce runnability by causing increased steam usage, production restrictions or shutdowns, quality variability, and an increased contaminant load in the finished pulp.