Influence of Particle Size in Talc Suppression by a Galactomannan Depressant

Abstract

Flotation behavior of different sizes of particles may follow different trends. The influence of particle size in talc suppression by a depressant galactomannan was studied in this research. The flotation response and mechanism were examined by flotation tests, modified flotation rate constant and entrainment recovery calculation, laser particle size experiments, adsorption tests, and advancing contact angle measurement as well as scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). The maximum recovery increased with particle size increases in the absence of galactomannan FPY (Fenugreek polysaccharide). The obviously suppressed effect was observed for the size fraction of −74 + 38 µm after reacting with FPY, but low efficiency was received for −38 µm and −10 µm, respectively. Laser particle size analysis indicated that the FPY has a certain function for the flocculation of fine particles. It is beneficial for reducing recovery by entrainment. EDS and advancing contact angle test results showed that the difference in contact angles probably is a result of genuine differences in the quantity of O and Mg bearing surface species, while the contact angle varied with particle size fraction in the absence of FPY. Adsorption and SEM test results demonstrated that in the case of −74 + 38 µm, the depressant adsorption density on the mineral surface is higher than the other two size fractions. On the whole, FPY probably is not enough of a depressant for talc suppression.

Talc Flotation—An Overview

“…Since smaller particle sizes would have a larger edge-to-face ratio [40], the contact angle could also be smaller for these particles than larger ones. However, with the depressants' presence, the contact angle might be lower for larger particles as the depressant adsorption density could be higher compared to smaller particles (Table 5) [54]. Thus, the talc contact angle is correlated to the surface coverage, and its surface wettability is influenced by the effect of polymer adsorptions [55].…”

A New Collector for Effectively Increasing Recovery in Copper Oxide Ore-Staged Flotation

“…where R ent,i is the recovery by entrainment (for particle size i), R w is the water recovery, and ENT i is the degree of entrainment for particle size i. An empirical mathematical model [16] for the degree of entrainment was proposed to relate the degree of entrainment to particle size and density, as shown in Equation 3:…”

“…In the experimental test system, the average particle size of the particles was less than 30 µm, so it can be assumed that all the malachite particles were close to being spherical particles; secondly, the viscosity of the slurry with different collector grades of malachite under the condition of adding the collector using rheometer test, the results show that the viscosity of the pulp tends to be the same under the three-grain condition, which is about 1 mPa•s, which is the viscosity of water at room temperature (20 • C). This is because the concentration of the slurry used in the single mineral flotation test is as low as about 4.7%, resulting in the viscosity of the slurry being close to the viscosity of water [16]. In summary, this experiment can be calculated by the empirical formula provided in Section 2.2.2.…”

“…It is difficult to overcome the energy barriers between the ore particles and the bubbles then adhere to the surface of the bubbles. Besides, the large specific surface area and high surface energy cause severe non-selective agglomeration between the gangue particles and the valuable particles, resulting in a larger amount of reagent consumption during the flotation process and a decreasing in the selectivity of reagent adsorption [14][15][16][17].…”

“…Part of −25 µm slime could not be effectively treated and was stranded for a long time. Chen et al [16] have shown that it is possible to increase the size of the fine particles by performing flocculation between particles, which enables the effective recovery of fine-grained minerals. The selective flocculation process was to add a polymer collector to the slurry after slurry adjustment, and selectively flocculated the target mineral under the action of shearing field, and then used flotation, re-election or de-sludge processes to achieve the separation of target minerals.…”