Effets de l'acidité et de la nature de l'acide sur la dissolution du phosphate naturel de Hahotoé-Kpogamé (Togo) par quelques acides conventionnels

Abstract: Acidity and acid''s nature effects on natural phosphate of Hahotoé-Kpogamé (Togo) dissolution by some conventional acids. With a view to enhancing the use of the phosphate rock of Hahotoé-Kpogamé (Togo), the effects of acidity and of some conventional acids'' nature on attack dissolution of this natural material have been investigated. Monitoring of rock dissolution has been carried out via P2O5 measurement in filtrates by means of a colorimetric method. According to the obtained results, the importance of rock dissolution depends on the acidity of the solution, whatever the acid''s origin (organic or mineral). Nevertheless, for organic acids'' solutions, phosphate dissolution continues in solutions with poor hydronium-ion content. As mentioned in the literature, this type of dissolution depends on metallic ions complexation by carboxylic functions. [Copyright &y& Elsevier]