In sulphite mills, lignin is extracted as lignosulphonate. There are many uses for lignosulphonate, for example in production of concrete and drywall, for facilitating oil and gas drilling, as raw material for several chemicals, and as a dispersant in water treatment formulations and textile dyes.

Alfa Laval supplies membranes for filtrating out lignosulphonate from spent sulphite liquor. These filters are characterized by: 

• High yield and product quality
• No filter cake – consistent flow and product quality
• Easy to expand thanks to modular design
• High reliability and fully automated operation
• No need for additives
• Low operating and installation costs
• Long membrane lifetime