Comprehensive utilization of rubidium mica ore

Abstract

In light of the serious environmental pollution caused by the conventional roasting processes and the corresponding low comprehensive utilization of rubidium resources, a novel acid leaching and solvent extraction process was developed to extract rubidium from rubidium mica ore.The effects of leaching temperature, sulfuric acid concentration, and time on the leaching of rubidium were investigated, and the phase transformations during the leaching were analyzed through X-ray diffraction(XRD), scanning electron microscope(SEM), and energy dispersive spectrometry(EDS).The experimental results show that the optimum conditions of acid leaching for rubidium mica ore are as follows: leaching temperature of 250 ℃, H2SO4 concentration of 200 g·L－1, and leaching time of 1 h.Under these conditions, the leaching ratio of rubidium increases up to 85. 2%.The XRD patterns of the raw ore indicate that quartz, biotite, muscovite, orthoclase, and albite are the major phases.Further SEM-EDS analysis shows that the Rb is scatted in biotite and muscovite in the form of isomorphism.Furthermore, the main reaction in the leaching process was the dissolution of the rubidium-rich micas.The countercurrent extraction experiment was conducted under the following conditions: extractant concentration of 1 mol·L－1, phase ratio(O/A)of 3:1, and extraction stage 3.The concentration of rubidium in the raffinate was 0. 003 g·L－1, and the extraction ratio of rubidium was 98%.After performing the 2-stage countercurrent stripping with 1 mol·L－1 HCl at a phase ratio(O/A)of 4:1, the stripping ratio of rubidium reached 99%.Silica white was prepared via alkali melting leaching residue and neutralization precipitation; thus, the comprehensive utilization of rubidium resource was achieved.XRD and Fourier transform infrared spectroscopy were used to characterize the silica white product.The corresponding results show that the product comprises hydrated silica, thus meeting the characteristics of the amorphous silica white.Finally, the chemical quantitative analysis results show that the silica white product comprises 91. 65% of SiO2, which is in accordance with the national chemical industry standard.

Keywords

• rubidium mica
• acid leaching
• solvent extraction
• rubidium
• silica white