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Optimization of Rock Salt Washing Process to Remove Selected Chemical Impurities in Lake Katwe Rock Salt

Rich deposits of mineral salts, present in substantial economic quantities, characterize the geological bounty of Uganda. The primary location of this wealth is lake Katwe, a saline crater lake southwest of the country. However, all grades of rock salt extracted from Lake Katwe remain contaminated with chemical impurities such as calcium, magnesium, heavy metals and sulphate ions, even after solar evaporation process from the salt pans. There is a need to conduct research into possible contaminant removal methods which could increase the market value of the extracted salt, and add to the body of knowledge for future salt processing and chlor-alkali industries in Uganda. This study examined the effect of varying water volumes and temperature on the levels of Calcium, Magnesium and Sulphate ions in rock salt samples from Lake Katwe. The samples were methodically crushed and washed. The salt was then dissolved, crystallized, dried and meticulous analysis to determine the concentration of these impurities was carried out. The data was analysed and represented in Microsoft Excel and MATLAB. Results obtained revealed that a temperature of 40°C and salt-water ratio of 1:2 are the optimal parameters for maximum reduction of calcium, magnesium and sulphate impurities in rock salt. This analysis enhances the purity of salt harvested from Lake Katwe’s solar evaporation process and offers optimal washing parameters to reduce impurities in brine, thereby improving plant yield and reducing production costs across various salt grades. It also provides new information to the mining communities at Lake Katwe on how to affordably improve the percentage purity of their rock salt. The study will also contribute novel industry-tailored data for future prospective salt processing and chlor-alkali industrial plants near the Lake while also filling a knowledge gap for further research on rock salt purification.

Rock Salt, Chemical Impurities, Salt Washing, Temperature, Composition, Lake Katwe

APA Style

Mirembe Sophia Katooko, Wanasolo William, Serwadda Joseph, Kasule Hannah Talinda, Katuhamye Silas, et al. (2023). Optimization of Rock Salt Washing Process to Remove Selected Chemical Impurities in Lake Katwe Rock Salt. American Journal of Applied and Industrial Chemistry, 7(1), 8-16.

ACS Style

Mirembe Sophia Katooko; Wanasolo William; Serwadda Joseph; Kasule Hannah Talinda; Katuhamye Silas, et al. Optimization of Rock Salt Washing Process to Remove Selected Chemical Impurities in Lake Katwe Rock Salt. Am. J. Appl. Ind. Chem. 2023, 7(1), 8-16. doi: 10.11648/j.ajaic.20230701.12

AMA Style

Mirembe Sophia Katooko, Wanasolo William, Serwadda Joseph, Kasule Hannah Talinda, Katuhamye Silas, et al. Optimization of Rock Salt Washing Process to Remove Selected Chemical Impurities in Lake Katwe Rock Salt. Am J Appl Ind Chem. 2023;7(1):8-16. doi: 10.11648/j.ajaic.20230701.12

Copyright © 2023 Authors retain the copyright of this article.
This article is an open access article distributed under the Creative Commons Attribution License ( which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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