Abstract
Flotation tests of synthetic mixtures of celestite (SrSO4) and calcite (CaCO3) minerals using
sodium dodecyl sulfonate as collector were carried out using a factorial experimental design 23.
The independent experimental variables included celestite grade in the feed (50% and 90%
SrSO4), conditioning pH (6.5 and 9) and sodium silicate depressant concentration (10-5 and 10_ 3
M). All experiments were performed at a constant collector concentration (10-4 M) and conditioning
time of 15 min. The response variables were recovery and grade of SrSO4 in the concentrate.
The factors that had the greatest effect on the grade and recovery of celestite were the celestite
grade in the feed (L) and the depressant concentration (C); also the combination of these
factors significantly affected the response variables. The highest celestite yield (96% recovery,
98% grade) was obtained when a 90% of celestite grade in the feed was used.
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