Managing calcium oxalate scale in the bleach plant

Alan W. Rudie; Peter Hart

Treesearch

Managing calcium oxalate scale in the bleach plant

Informally Refereed

Authors:

Alan W. Rudie, Peter Hart

Year:

2005

Type:

Miscellaneous Publication

Station:

Forest Products Laboratory

Source:

Solutions : for people, processes and paper. (June 2005): Pages 45-46

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Download (PDF 238 KB): https://research.fs.usda.gov/download/treesearch/28808.pdf

Abstract

To comply with the U.S. Environmental Protection Agency's "Cluster Rule," most U.S. mills have switched from the use of chlorine to chlorine dioxide as the oxidant in the first stage of bleaching. This process change has a downside. it increases the formation of mineral scale in bleach plants. Typically, calcium oxalate forms in the chlorine dioxide stages and calcium carbonate in the extraction stages. Many mills have directly linked significant production losses, increased maintenance costs, and increased bleach chemical costs to calcium-based scale formation.

Keywords

Incrustations, pulp mills, bleaching, oxalic acid, calcium oxalate, mathematical models, pulp and paper processes, scale, digesters, chemical precipitation

Citation

Rudie, Alan; Hart, Peter. 2005. Managing calcium oxalate scale in the bleach plant. Solutions : for people, processes and paper. (June 2005): Pages 45-46