Ulexite Dissolution with Carbon Dioxide at High Pressure

VALDEZ SILVANA; FLORES, HORACIO RICARDO; SERRANO EMILIO

Handbook on Borates: Chemistry, Production and Applications

Nova Science Publishers

Lugar: Nueva York; Año: 2009; p. 383 - 397

Boron compounds have found a wide spectrum of applications. This industry has been growing interestingly in the last years. In spite of its useful utilities, it produces sludges and brines with an important amount of B2O3, which, at high concentrations, has deadly effects on plants. Thus, lately, new less contaminant production methods have been under researchers consideration. This chapter studies the dissolution that the ulexite undergoes when its suspension with water is leached with carbon dioxide at high pressure. Pressure is applied to obtain better gas solubility. It could be obtained a mixture of borax and boric acid or they could react together to form sodium pentaborate. Besides, by controlling the pH of the final solution, borax, boric acid or other boron products which have major added value could be obtained separately. The advantage of the method used is the possible reduction of acid pollution because current mineral acids employed can be replaced by carbon dioxide for the lixiviation process.  These experiments were performed at pressures less than 11 kg/cm2, to study the feasibility of the method.