METHOD AND A SYSTEM FOR PRECIPITATION OF CALCIUM CARBONATE AND A PRODUCT COMPRISING CALCIUM CARBONATE

摘要

A method for precipitating calcium carbonate, in which method calcium hydroxide is introduced to a fiber suspension containing cellulose-containing fibers, the calcium hydroxide is allowed to attach onto the surfaces of fibers for a pre-determined time, and the aqueous suspension of calcium hydroxide and fibers is brought into contact with carbon dioxide for precipitating the calcium carbonate. A corresponding system for precipitating calcium carbonate in connection with cellulose-containing fibers and a fibrous product, which comprises pulp material produced by the method and comprising calcium carbonate, are also set forth.

主权项

1. A method for precipitating calcium carbonate onto surfaces of cellulose-containing fibers in a refining process, comprising:
introducing calcium hydroxide before refining to a fiber suspension comprising cellulose-containing fibers, allowing calcium hydroxide to attach onto the surfaces of the fibers for a pre-determined time period, refining the fibers, and bringing the aqueous suspension of calcium hydroxide and fibers into contact with carbon dioxide after refining in order to precipitate calcium carbonate.