Effect of Dehydration Treatment on Dissolution of Ulexite in Ammonium Sulfate Solutions

Ulexite is commercially one of important boron minerals, and it is found abundantly in Turkey. Ulexite is generally available together with other borates, and it can be used as a raw material in the production of boron compounds. It includes a significant amount of hydration water. When ulexite is subjected a dehydration process, it loses some part of hydrate water depending upon applied temperature. A porous solid is obtained in consequence of dehydration treatment, and the solid material becomes more chemically active. The resulting porous structure allows occurring more readily the reaction between solid and fluid, and the dissolution rate increases. In this study, the dissolution kinetics of calcined ulexite in ammonium sulfate solutions was examined. In the experiments, the effects of the dehydration temperature, solution concentration, reaction temperature, solid-to-liquid ratio, and stirring speed on