Purified Precipitated Calcium Carbonate and Purified Calcium Silicate Compounds, a Method for Their Production, and Their Use as Paper Fillers

摘要

Methods for the production of high purity calcium carbonate and high purity calcium silicate. Products are washed before introduction into a paper machine furnish, to avoid filler loss and brightness reversion. In one embodiment, multiple superatmospheric reactors may be provided, for switching production between reactors, and advantageously utilizing process waste heat. On site production of both precipitated calcium carbonate and calcium silicate hydrates is thus achieved in a paper mill.