Q.1092: What percentage of pulping chemicals are recovered or recycled?
Ans. About 98-99% of pulping chemicals are recovered and recycled. The process is called Chemical Recovery. In kraft pulping about 5 - 15 Kgs Sodium Sulfate (Na2SO4) is used per metric ton of pulp produced.
For a simplified flow chart showing the pulping and chemical recovery process for Kraft pulping, click at Kraft Pulping and Chemical Recovery Flow Chart