Mechanism of Quartz Flotation Enhanced by Calcium Ion
摘要
In this paper, the flotation mechanism of Ca2+-reinforced quartz adsorbing sodium oleate was systematically explored. According to the result of the single mineral flotation test, Ca2+ significantly activated the flotation of quartz. At pH = 12, C(Ca2+) = 0.5 mmol/L and C(NaOL) = 0.5 mmol/L, the flotation recovery of quartz reached a maximum of 95.74%, whereas the recovery of quartz without additional Ca2+ was only 14.91%. According to the SEM-EDS data, Ca2+ was successfully adsorbed on the quartz surface, with an approximate adsorption quantity of 3.97%. The characteristic peak of NaOL was more visible following the interaction of quartz with Ca2+ than before, according to the FTIR measurements. The adsorption capacity of Ca2+-added quartz on NaOL was greater than that of Ca2+-free quartz, according to the results of an ultraviolet-visible spectrophotometer. The enhancement effect, measured by the supernatant's light transmittance, was approximately 8.29%. According to the solution chemistry calculation, the primary particle influencing the quartz's ability to adsorb sodium oleate is Ca(OH)+. Comparing the system with Ca(OH)+ to the system without Ca(OH)+, the molecular dynamics simulation reveals that the adsorption start point is advanced by roughly 1 Å and the adsorption optimum point is advanced by roughly 14 Å. The water molecules without and with Ca(OH)+ added have diffusion coefficients of 5.04 × 10−5 cm2/s and 3.15 × 10−5 cm2/s, respectively, and interaction energies of − 7.13 kcal/mol and − 101.06 kcal/mol, respectively. This indicates that the hydrated film that forms on the surface of the quartz with Ca(OH)+ added is thinner and that the agent-quartz interaction effect is also better. To summarize, by altering the conditions of the adsorption onset point of quartz, adsorption optimum point, adsorption maximum, adsorption mode, and adsorption energy, Ca(OH)+ improved the adsorption effect of quartz on OL−.