{"title":"The solubility of calcium carbonate in green liquor handling systems","authors":"Alisha Giglio, V. Papangelakis, H. Tran","doi":"10.32964/tj18.10.595","DOIUrl":null,"url":null,"abstract":"The formation of hard calcite (CaCO3) scale in green liquor handling systems is a persistent problem in many kraft pulp mills. CaCO3 precipitates when its concentration in the green liquor exceeds its solubility. While the solubility of CaCO3 in water is well known, it is not so in the highly alkaline green liquor environment. A systematic study was conducted to determine the solubility of CaCO3 in green liquor as a function of temperature, total titratable alkali (TTA), causticity, and sulfidity. The results show that the solubility increases with increased temperature, increased TTA, decreased causticity, and decreased sulfidity. The new solubility data was incorporated into OLI (a thermodynamic simulation program for aqueous salt systems) to generate a series of CaCO3 solubility curves for various green liquor conditions. The results help explain how calcite scale forms in green liquor handling systems.","PeriodicalId":22255,"journal":{"name":"Tappi Journal","volume":null,"pages":null},"PeriodicalIF":0.6000,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Tappi Journal","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.32964/tj18.10.595","RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"MATERIALS SCIENCE, PAPER & WOOD","Score":null,"Total":0}
引用次数: 0
Abstract
The formation of hard calcite (CaCO3) scale in green liquor handling systems is a persistent problem in many kraft pulp mills. CaCO3 precipitates when its concentration in the green liquor exceeds its solubility. While the solubility of CaCO3 in water is well known, it is not so in the highly alkaline green liquor environment. A systematic study was conducted to determine the solubility of CaCO3 in green liquor as a function of temperature, total titratable alkali (TTA), causticity, and sulfidity. The results show that the solubility increases with increased temperature, increased TTA, decreased causticity, and decreased sulfidity. The new solubility data was incorporated into OLI (a thermodynamic simulation program for aqueous salt systems) to generate a series of CaCO3 solubility curves for various green liquor conditions. The results help explain how calcite scale forms in green liquor handling systems.
期刊介绍:
An internationally recognized technical publication for over 60 years, TAPPI Journal (TJ) publishes the latest and most relevant research on the forest products and related industries. A stringent peer-review process and distinguished editorial board of academic and industry experts set TAPPI Journal apart as a reliable source for impactful basic and applied research and technical reviews.
Available at no charge to TAPPI members, each issue of TAPPI Journal features research in pulp, paper, packaging, tissue, nonwovens, converting, bioenergy, nanotechnology or other innovative cellulosic-based products and technologies. Publishing in TAPPI Journal delivers your research to a global audience of colleagues, peers and employers.