Preparation of Magnesium Hydroxide from Magnesite by means of Mechanochemical Treatment and its Reactivity.

Abstract

Mechanochemical process for producing Mg (OH) 2 from magnesite (MgCO3) without heat treatment has been developed. This process is composed of two steps: The first step is to produce Mg (OH) 2 and Na2CO3 mechanochemically by dry grinding the mixture of magnesite and solid NaOH powders in a mill. The reaction between the two starting samples proceeds as the grinding progresses. The second step is to separate Na2CO3 from the insoluble products in the ground mixture by washing with water. Reactivity of the insoluble products against H2SO4 solution is improved with increasing the grinding time, and levels off in the prolonged grinding. The reactivity of the insoluble products prepared from the mixtures ground for 0 minutes or more is much higher than that of magnesite powder. The separated Na2CO3 can be reused for appropriate purposes