Hydrodynamics and mass exchange in apparatus with mixers during the reaction of neutralization of aggressive waste water

Ensuring the environmental safety of the enterprise is a rather urgent problem of modern production. Aggressive wastewater generated in the technological process must be neutralized in apparatus with agitators. The chemical reaction of neutralization is instantaneous, therefore, the main limiting factor is the hardware design of the process to ensure that all lime particles are kept in suspension in order to increase the surface area of phase contact. The purpose of this work is a theoretical analysis of mixing in a liquid-solid system [1], which allowed the development of a new design of a stirrer for suspending solid particles in a liquid. The criteria for scaling the results of laboratory experiments are considered. The experimental part was carried out on the example of the process of sulfuric acid neutralization with lime milk in the enterprise JSC “Svyatogor”. A method for calculating a conical mixer for suspension processes in a liquid-solid system has been developed. Through the introduction of a new design of the mixing device, it was possible to reduce the neutralization reaction time by 2 times while reducing energy consumption by 36%.

Grigorieva A. N., Abiev R. Sh. Hydrodynamics and mass exchange in apparatus with mixers during the reaction of neutralization of aggressive waste water. MIAB. Mining Inf. Anal. Bull. 2022;(5—2):209—219. [In Russ]. DOI: 10.25018/0236_1493_2022_52_0_209.

Grigorieva A. N., Cand. Sci. (Eng.), https://orcid.org/0000-0001-6825-7003, General Director of Asterion LLC, 195197, Russia, St. Petersburg, Prosveshcheniya, 85, an@td-elma.ru;
Abiev R. Sh., Dr. Sci. (Eng.), Professor, https://orcid.org/0000-0003-3571-5770, Head of the Department “Optimization of Chemical and Biotechnological Equipment”, St. Petersburg State Technological Institute (Technical University), 190013, Russia, St.-Petersburg, Moskovsky prospect, 26, rufat.abiev@gmail.com.

Grigorieva A. N., e-mail: an@td-elma.ru.

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