Physicochemical Properties of Borates from Southamerican Puna

H. FLORES, L. MATTENELLA, S. VALDEZ

Río de Janeiro, Brasil

Congreso; VI Southern Hemisphere Meeting on Mineral Technology; 2001

CETEM - PUC RIO- UFRJ

Since most of the borates produced in Argentina (concentrates and processed products) are exported and the technical marketing regulations have become more severe, producers have to improve competitiveness through technology including some concentration and/or purification stage in the mill circuit. The objective of the separation is a graded product in B2O3 and lowered in undesirable impurities (mainly iron, chlorides and sulphates). Concentration steps usually involved in the borate processing are gravity separation, froth flotation, size classification and magnetic separation, based on the differences of specific weight, superficial energy, hardness and magnetic susceptibility, respectively. Another easy grading method is calcination. This is the conversion to a less hydrated crystalline form. Unfortunately, also impurities are graded.This paper reports the results obtained of the above mentioned properties for the following industrial interesting South American borates: sodium (tincal), calcium (colemanite and inyoite), sodium and calcium (ulexite) and calcium and magnesium (hydroboracite) borates. Also, the techniques employed to collect pure samples are commented. This work has been carried out at the INBEMI with financial support of ANPCYT (SECYT), BID 802/OC-AR PICT No 07-0-02059/07464 projects