Perfecting of a Dry Cationing of Starch

Abstract

In recent years the output of paper and paper products from cellulose considerably rose, as a result the amount of colloid impurities in household and sewage waters, which need to be coagulated and removed from the enterprise also increased. Special modified starch with positive charge - cationic starch is applied to these purposes. This starch is manufactured with use of chemical reagents in an alkaline medium. To increase the process efficiency of a cationing in VNIIK there was studied a dry process of receiving cationic starch (CS) which allows to reduce necessary floor spaces, to reduce considerably water consumption, electro-and heat power. That results in the increased yield of end products and reduced losses of dry solids. In the article there are the results of studying of influence on process of a cationing with dry calcium hydroxide instead of sodium hydroxide activator. It is established that calcium hydroxide reduces viscosity of starch and promotes successful carrying out the process. It is shown that the dry cationing efficiency of starch depends on a consumption of reagent, water and duration of processing, so essential advantages of the dry cationing to a wet method are noted. It is studied the influence of a botanical type of starch on results of an etherification cereal starches, in particular, corn and amylopectin are the most active ones under identical conditions of process. Introduction of the dry cationing will allow to improve considerably an ecological situation both at starch, and pulp-and-paper enterprises. In the All-Russian Research Institute of Starch Products there is developed a normative documentation for the production of cationic starch by a dry process.