Effect of various forms of silicic acid in uranium-containing solution on formation of stable emulsion in solvent extraction

A stable emulsion easyly appears, if acid leached solution from silicate uranuim ore containing more fluorite is treated by solvent extraction process. The relationship between formation of stable emulsion and silicic acid forms in solvent extraction has been studied by chemical analysis and electron microscope. It shows that the active silicic acid, intermediate polymerized silicic acid and silica gel can not lead to stable emulsion formation. The silicic acids of emulsion-causing are high polysilicic acids. The forms of various silicic acids in solution determine either the stable emulsion appears or disappears. If microamount of fluorine is present in solution, it will accelerate the polymerization of silicic acid to form high polysilicic acid. But, the over-amount of fluorine will depolymerize the high polysilicic acid to form active silicic acid. Aluminium and iron are complexed with fluorine and inhibit the effect of free fluorine in solution. The high polysilicic acid can be removed by adding polyether