RECOVERY OF NIOBIUM FROM TAILINGS GENERATED
THROUGH THE PROCESSING OF APATHIC ORES.
Apatitic ore; tailings; niobium; metallurgical recovery; and optimization
Brazil has one of the world's largest reserves of niobium. In apatite beneficiation processes, niobium minerals are often found and have an extremely fine granulometry and are commonly disposed in a dam. The objectives of this work were: to evaluate, through the kinetic study of flotation, the metallurgical recovery rates of niobium ore for different granulometric ranges and to use the response surface techniques and statistical design of experiments. In this context, samples were collected from the apatite processing tailings streams that have a high niobium content and incorporated into the samples for niobium flotation. Bench flotation tests were carried out and a subsequent kinetic adjustment was carried out, based on the accumulated metallurgical recovery data. An experimental design of the type Central Composite Rotational Design (CCRD; Central Composite Rotational Design) was initially used, which is part of the response surface methodology (RSM; Response Surface Methodology), with the proposal of finding the optimal points of the main variables, given the simultaneous analysis of the three response variables. As a result, the highest value found for the kinetic constant was 0.0195 s-1, corresponding to granulometry below 37μm. When using the response surface technique, with the optimization of the variables, a metallurgical recovery of 70% was obtained for the granulometric range below 37μm. It is concluded that for the optimization of the niobium flotation process, the granulometry must be kept below 37μm and above 5μm, so that significant losses do not occur in the process. The optimization of the results and the collector dosage factors, pH and surfactant/collector partition to be considered optimal were 881 g/ton, 6.7 and 24%/76%, respectively