Magnesium hydroxide is used in a number ofindustrial applications, from the neutralisation of acid effluentsto the production of pharmaceuticals. High-quality magnesiumhydroxide powders can be produced by hydrating slow-reacting magnesia in dilute magnesium acetate solutions. Theprocess of magnesia hydration shows many similarities with atypical hydrometallurgical leaching operation; however, itskinetics are crucial not only for process design and control, butalso for the production of powders with a desirable particlemorphology. This article shows the results of an experimentalwork whereby industrial heavily-burned magnesia powderswere hydrated in 0.01 to 0.1mol/L magnesium acetatesolutions at temperatures ranging between 333 and 363K.Examination of the magnesium hydroxide produced and theanalysis of the kinetic data suggest that the hydration ofheavily-burned magnesia in magnesium acetate solutions is adissolution-precipitation process controlled by the dissolutionof magnesia particles. The activation energy was estimated tobe 60kJ/mol, while the reaction order with respect tomagnesium acetate concentration was found to be about one.
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