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 Certification

Production Workshop

FAQ

Q1: What calcium‑based products do you mainly produce? 

A1:  We specialize in manufacturing calcium oxide (quicklime) and calcium hydroxide (slaked lime, hydrated lime). Various specifications in particle size and purity are available. Custom industrial‑grade products are supported to meet procurement demands from diverse industries.

Q2: What industries are calcium oxide and calcium hydroxide mainly applied to? 

A2:  Calcium oxide is widely used in pH adjustment for sewage treatment, metallurgical desulfurization, building materials, soil improvement and chemical raw‑material production. Calcium hydroxide is largely adopted in flue‑gas desulfurization, wastewater treatment, putty & coatings, leather processing,  food and pharmaceutical auxiliary materials and other fields.

Q3: What advantages do your products have over competitors? 

A3:  We own our production base with stable raw‑material supply. Our products feature low impurity content and high activity. Stable quality with complete test reports is guaranteed. Custom production and short lead‑time for bulk full‑truck orders are supported. Technical support is also available after‑sales.

Q4: Can you export calcium oxide and calcium hydroxide? Which regions do you mainly export to?

A4:  Yes, we export calcium oxide and calcium hydroxide worldwide. Our products are mainly exported to Southeast Asia, the Middle East, Africa and other regions. We are familiar with cross‑border export procedures and can provide relevant export documents for customers.

Q4: What packing options are available for export? 

A4: Multiple packing options are available for export. We offer jumbo bags, 25kg woven bags with moisture‑proof reinforcement suitable for ocean shipment. Custom printed packing is also acceptable.

Q5: Can you provide samples?

A5:  Yes, we can provide samples of calcium oxide and calcium hydroxide.