Ion flotation of lanthanum(III) and holmium(III) from nitrate and nitrate-chloride media

Abstract

Ion fl otation of lanthanum(III) and holmium(III) from nitrate and nitrate-chloride solutions with sodium dodecyl sulfate was studied. The distribution coeffi cients and their dependence on pH were determined.The development of modern technologies requires an even growing number of new materials. Rare earth metals (REMs) play an important role in metallurgy, glass and ceramic manufacturing, and other industries. Cerium lanthanides (lanthanum, cerium, and neodymium) and some yttrium lanthanides (holmium, samarium, and europium) are the most widely used individual REMs. Misch metal containing 50% cerium, 30% lanthanum, 15% neodymium, and 5% praseodymium is extensively used in steel treatment to remove free oxygen and sulfur and the impurities of lead and antimony. Lanthanum oxide is an important component of the optical glass used in the manufacture of laboratory glassware with high thermal stability and acid resistance. Holmium is a component of some magnetic alloys; its compounds have found limited application in the preparation of special glass, phosphors, and some materials for microelectronics.Individual REMs are most in demand in the global market. The diffi culties consist in separating the certain element from their sum and a small number of viable REM deposits. In Russia, the main source of rare metal raw is loparite ore of the Lovozerskoe deposit [1, 2]. Therefore, it is necessary to develop a technology for obtaining a wide assortment of individual rare earth elements. Ion fl otation, ensuring production of a concentrate containing 60-70% of REM oxides, is the promising technology.The removal of lanthanides with naphthenic acid on addition of chlorides to the concentration 0.1-0.15 M decreases the distribution coeffi cient due to the formation of nonextractable chloro complexes [3]. Because the chloro complexes have the different strengths, this decrease is different for each lanthanide, and, consequently, the factor of the Ce/Y separation increases from 1.5 to 14. In ion fl otation of REMs, the separation factors are low [4]. Therefore, it is of interest to study the effect of chloride ions on the ion fl otation process.The ion flotation was performed during 5 min on a 137 V-FL laboratory flotation machine with a chamber volume of 1.0 dm 3 . As model solutions were used 0.001 M solutions of lanthanum and holmium nitrates (both chemical purity grade). The volume of the solution was 200 ml. As surfactant served dry sodium dodecyl sulfate (SDS) whose concentration corresponded to the stoichiometry of the reactioni.e., it was 0.003 M (DS -is the dodecyl sulfate ion).To initial solution, sodium chloride was also added in amount corresponding to the concentrations 0.01 and 0.05 M. At 0.1 M NaCl the lanthanide fl otation is inhibited virtually completely. The resulting solution (foam product) and the solution remaining in the chamber (chamber residue) were separated and analyzed. The foam was disintegrated by addition of 1 M sulfuric acid. The concentration of REMs was determined photometrically with Arsenazo-...

A review of the applications of ion floatation: wastewater treatment, mineral beneficiation and hydrometallurgy

“…16 The same phenomenon was also found when oating and concentrating La(III) from nitrate and nitrate-chloride solutions with dodecyl sulfate as the collector. However, the addition of chloride ions did not signicantly improve the ion otation of holmium(III); also, the distribution coefficient increased with the addition of chlorides and reached the maximum at a sodium chloride concentrate of 0.01 M 83 .…”

“…Rare-earth elements are widely used in semiconductors, electronic components, alloys, metallurgy, glass and ceramic manufacturing, special materials, and other industries; they have long been considered to be a strategic mineral resource. 83 However, rare earth industries face the difficulty of separating certain elements from their sum. Ion otation is a promising technology for ensuring production of concentrates containing 60% to 70% rare earth elements.…”

Ion flotation and its applications on concentration, recovery, and removal of metal ions from solutions

“…The same phenomenon was also found when floating and concentrating La(III) from nitrate and nitrate-chloride solutions with dodecyl sulfate as the collector. (Chirkst et al, 2012).…”

Ion flotation for removal of Ni(II) and Zn(II) ions from wastewaters

“…The removal of heavy metals such as Cu(II), Zn(II), Cr(III) and Ag(I) from wastewaters was studied using sodium dodecyl sulfate (SDS) and hexadecyltrimethyl ammonium bromide as collectors, obtaining a maximum metal removal of 74% (Polat and Erdogan, 2007). Ion flotation has also been used for other ions such as removing halide complexes of aluminum subgroup metals, Ce(III), Y(III), La(III), Ho(III), Cr(VI), Co(II), Cu(II), Ag(I) and Au(II) (Ghazy et al, 2008;Chirkst et al, 2009;Reyes et al, 2009, Strel'tsov andAbryutin, 2010;Chirkst et al, 2012;Mal'tsev and Vershinin, 2012). Removal of cadmium with SDS as collector was studied by ion flotation.…”