Novel Talc for Deposit Control of Pulps Rich in Anionic Trash, 2001 Pulping Conference Proceedings

J. Reynolds, J. L. Yordan--The existing laboratory pitch and stickies deposition tests involving the use of artificial pulp doctored with adhesives or wood pitch may not best simulate the real papermaking conditions. A new test method using mill produced pulp samples was used to evaluate the amount of depositable material present in pulps.

This test was used to compare the effectiveness of several pitch and stickies control additives including a new surface treated talc, specifically designed to control deposits in papermaking processes where high amounts of anionic trash are present. Deposition tests were conducted using old newsprint pulp (ONP), thermo-mechanical pulp (TMP), and coated broke.

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.