Reuse of iron ore using vegetable oils as collectors
Flotation; iron; vegetable oil; palm; soy
Flotation is a process widely used in the mining and mineral processing industry, whose main objective is to separate valuable minerals from derived minerals, based on their physicochemical properties. This technique is based on the ability of minerals to adhere to air bubbles or other chemical agents, forming a foam that can be separated from the rest of the material. Historically, petroleum-based synthetic chemical collectors have been the most used in iron ore flotation due to their effectiveness. However, the search for alternatives has driven the study of replacement by vegetable oils. They are mainly composed of triglycerides, which have groups capable of interacting with ore particles, presenting interesting characteristics as collectors in iron flotation. In this sense, the present work aims to evaluate the use of saponified palm and soybean oils as collectors in the reuse of iron ore. The oil profile was defined based on acid value, iodine value, saponification value and Fourier Transform Infrared Spectroscopy (FTIR). The ore waste was characterized based on granulometric analysis and X-ray fluorescence (XRF). The initial microflotation tests were carried out in a Hallimond tube, with a waste concentration of 40 mg/L, for 4 minutes, varying the concentration of the collectors at 10, 40 and 70 mg/L and the aeration between level and mode. The flotate was collected, dried in an oven, prepared and analyzed by Molecular Absorption Spectroscopy to determine the iron content.