LABORATORY AND MILL EXPERIENCE S WITH A NOVEL TALC FOR DEPOSIT CONTROL OF PULPS RICH IN ANIONIC TRASH

摘要

Deposition tests were conducted using a new method on old newsprint pulp (ONP), thermo-mechanical pulp (TMP), and coated broke to determine the effectiveness of several pitch and stickies control additives. This included a new surface treated talc, specifically designed to control deposits in papermaking processes where high amounts of anionic trash are present. The laboratory results show the surface treated talc to very effective in controlling the depositable material in all the pulp samples tested particularly ONP and TMP pulps, which contained high anionic trash levels. This novel talc also reduced the total amount of anionic trash and turbidity of the treated pulps. The surface treated talc was more effective to use than the conventional coagulant treatments the mills were using at the time of the evaluations. The experience obtained with the new surface treated talc in two North American newsprint mill confirmed the laboratory findings that a pitch/stickies control program based on the novel talc is more effective than the ones based on either conventional talc or cationic fixatives.