White liquor

Photograph: David Ryder/Reuters The news of the collapse on May 26th of a tank storing 900,000 gallons of white liquor at the Nippon Dynawave Packaging paper mill by the Columbia River in Longview, Washington, may have raised the question in people’s minds as to just what “white liquor” might be. White liquor is a caustic alkaline solution used to break down solid wood chips in the creation of pulp for paper production. As Wikipedia has it “White liquor is a strongly alkaline solution composed mainly of sodium hydroxide and sodium sulfide. It is used in the first stage of the Kraft process in which lignin and hemicellulose are separated from cellulose fiber for the production of pulp. The white liquor breaks the bonds between lignin and cellulose. It is called white liquor due to its white, opaque color . . . White liquor also contains minor amounts of sodium carbonate, sodium sulfate, sodium thiosulfate, sodium chloride, calcium carbonate and other accumulated salts and non-process…