China Calcium Oxide Manufacturer Supply High Whiteness Calcium Oxide for Papermaking

Calcium oxide (CaO, commonly known as quicklime) has clear and significant applications in the paper industry, specifically in pulping, papermaking, and wastewater treatment.

1. Pulping Process (Chemical Pulping)

• Kraft Process: Calcium oxide is a component of "white liquor" (the pulping cooking solution), working together with sodium hydroxide and sodium sulfide to break down lignin in wood. This separates cellulose fibers, the primary raw material for paper.

• Recycling in Pulping: In the recovery of pulping waste liquid (black liquor), calcium oxide participates in chemical reactions to regenerate cooking agents, enhancing the efficiency and economic viability of the pulping process.

2. pH Regulation and Bleaching Assistance

• pH Control: During pulp washing, bleaching, and papermaking, calcium oxide adjusts the acidity of process water (typically maintaining an alkaline environment, pH 8–11). This stabilizes bleaching agents (e.g., hydrogen peroxide) and reduces equipment corrosion.

• Bleaching Enhancement: In oxygen bleaching or chlorine-free bleaching processes, calcium oxide maintains an optimal alkaline condition to improve bleaching efficiency, enhancing pulp whiteness and purity.

3. Wastewater Treatment

• Paper mill wastewater contains organic matter, pigments, and acidic substances. Calcium oxide is used to:

• Neutralize acidic wastewater, adjusting pH to the discharge standard (6–9);

• React with heavy metal ions to form hydroxide precipitates, remove pollutants, and coagulate suspended solids for accelerated water purification.

PACKAGING & DELIVERY

Qualification Certificate