STUDY OF KINETICS OF BELOPHOR OB CRYSTALLIZATION COMPLICATED BY CHEMICAL REACTION

The paper studies the effect of oxidizing agent and process parameters on the kinetics of crystallization, grain size and the output of optical bleacher. Currently, chemical and other industries widely use optical bleaching agents to bleach textile fibers, paper, plastics, etc. The effectiveness of these bleachers approximately quantum yield of fluorescence equal to the ratio of the number of emitted photons of light to the number of absorbed photons. This ratio of bleach (in solution) reaches 90 %. Among the optical bleaching agents an important place in the present study is occupied by the derivatives 4,4´-bis-(4˝-dietanolamino-6˝-(n-sulfanilino)- simmetric triazin-2˝-ilamino)-stilben-2,2´-disulfonik acid (trade name Belophor-OB- liquid). In the production of Belophor-OB-liquid (finished form is a 20 % aqueous solution, due to subsequent bleaching technology), the quality of the finished product is largely determined by the stage of selection (oxidizing) going together with the and the process of crystallization. These processes are determined by particle size distribution of the finished product, the concentration of the base material and additives that characterize the qualitative characteristics of the product. Existing methods of Belophor production have several disadvantages, including separation of fine crystals, and as a consequence, increase in the loss of the desired product at the stage of filtration and high concentrations of inorganic impurities. Evidence-based approach to the calculation and the choice of optimal process parameters of the crystallization process will get a product with higher quality characteristics (concentration of the desired product, composition of the dispersed solid phase, and concentration of impurities). Therefore, the study of the kinetics and modeling of the combined processes of selection is an urgent scientific and practical challenge in order to produce Belophor and other fine chemicals. The speed of crystallization process, complicated by a chemical reaction, in this case depends not only on the kinetics of formation of the crystalline phase (the rate of nucleation and crystal growth), but also on the kinetics reaction of the process: in