Quicklime, also known as calcium oxide (CaO), plays a crucial role in the paper and pulp industry. This highly reactive compound is widely used in various stages of paper manufacturing, contributing to efficiency, sustainability, and quality enhancement.

Quicklime Paper and Pulp (ảnh ngang)

1. Quicklime in the Kraft Process

The Kraft process, the most widely used method for producing pulp, actively breaks down wood chips into fibers through chemical treatment. Quicklime plays a crucial role in this process, particularly in the chemical recovery cycle. As pulping begins, cooking chemicals such as sodium hydroxide (NaOH) and sodium sulfide (Na₂S) work to dissolve lignin, freeing the cellulose fibers. Once digestion is complete, the spent liquor—known as black liquor—holds dissolved lignin along with essential inorganic chemicals.

To reclaim and recycle these chemicals, the black liquor first burns in recovery boilers, generating smelt. Next, this smelt dissolves in water, forming green liquor, which contains sodium carbonate (Na₂CO₃) and sodium sulfide. Quicklime then reacts with sodium carbonate in a process called causticizing, efficiently converting it back into sodium hydroxide for reuse in pulping. Ultimately, this closed-loop system significantly reduces waste while improving cost efficiency in paper mills.

2. Quicklime in Bleaching and Water Treatment

Beyond the Kraft process, people use Quicklime in water treatment and bleaching sequences. It helps regulate pH levels in water treatment facilities, neutralizing acidity and removing impurities. Additionally, in the bleaching process, quicklime aids in the production of calcium hypochlorite, as a bleaching agent.

3. Benefits of Quicklime in Paper Production

Environmental Sustainability: It enables the recycling of chemicals, reducing waste and emissions.
Cost Efficiency: Its role in chemical recovery decreases the need for fresh inputs, lowering production costs.
Process Optimization: Enhances pH control, improves fiber quality, and aids in wastewater management.

Conclusion

Quicklime is an essential component of the paper and pulp industry, playing a critical role in chemical recovery, bleaching, and water treatment. Its contributions to efficiency, sustainability, and cost reduction make it an indispensable material in paper manufacturing.

Harry - contact

VIET NAM TECHNOLOGY MINERAL JSC – SHC GROUP

Mr. Harry – International Sales Manager
WhatsApp: +84 936 165 098
Email: export8@shcgroup.vn