Optimization of the leaching conditions of an autoclave. Application to the dissolution of ferrocolumbite from San Luis Province, Argentina

MARIO RODRIGUEZ; MARÍA DEL C. RUIZ

LATIN AMERICAN APPLIED RESEARCH

PLAPIQUI(UNS-CONICET)

Lugar: Bahía Blanca; Año: 2011 vol. 41 p. 317 - 323

0327-0793

The aim of this work was to determine the optimum working conditions of a Parr laboratory autoclave for minerals dissolution, and to apply the obtained results to the leaching in HF medium of a mineral containing Nb and Ta from the Province of San Luis, Argentina. The optimized variables were heating rate, liquid volume, stirring speed, inert solid addition and cooling rate. The results of the experimental assays showed that changes in the liquid volume, stirring speed and the addition of an inert solid did not produce any modifications in the actual heating rate in the studied working ranges. The optimum heating programs ranged between 5 and 10°C/min and depended on the programmed final temperature. The optimum cooling period for the assayed temperatures was 25 min. The mineral leaching assays were carried out by varying temperature, HF concentration, stirring speed, solid-liquid relation, particle size, and reaction time. The results indicated that, using the optimum working conditions, more than 90% of mineral might be dissolved at 220°C. It was also observed that the dissolution of mineral was slightly affected by the stirring speed and the particle size whereas temperature, HF concentration, solid-liquid relation and reaction time strongly influenced the extraction of elements. These instructions are presented to assist authors in preparing a typescript which is suitable for direct photo-offset reproduction. The abstract should not exceed 200, 150 and 50 words for Review Papers, Articles and Notes respectively.