The Some Physicochemical Studies on Gallium(III) Salt Solutions.

Abstract

IKTRODUCTIONAmong the characteristics of the gallium-indium-thallium family essential to its systematic study are trends and variations in basicity. The combined effects of small size and comparatively high charge among the tripositive ions of these elements should render all of them quite highly acidic, but significant differences should be discernible as these factors vary. Variations in basicity hare been studied as part of a general investigation of comparative properties in this family. I t is the purpose of this communication to summarize results obtained with gallium(II1) compounds by the techniques of electrometric titration with alkali and measurement of pH as a function of salt concentration and to compare them with existent data for indium(II1) compounds.Previously reported measurements of these types have been limited in number and lacking in agreement. Fricke and Meyring (3) obtained data, based upon a hydrogen electrode study of titration of gallium(II1) chloride solutions with sodium and potassium hydroxides, which indicate precipitation of the hydrous oxide (9) in the vicinity of pH 2.8-3.1. Von Bergkampf (15) reported precipitation from hydrochloric acid solution at pH 3.4 and from sodium hydroxide solution at pH 9.7 as a result of single titrations of 0.1 N gallium(II1) chloride solutions, a quinhydrone electrode being used. More recently Ivanov-Emin and Rabovik (5) found from a hydrogen electrode study that precipitation from 0.01 M gallium(II1) chloride solutions began at pH 3.48-3.50 with 2.6 equivalents of sodium hydroxide added and was complete at pH 6.7-6.8 with 2.8-2.9 equivalents. With 0.005 M gallium(II1) sulfate solutions, however, precipitation began at pH 3.4C-3.45 with 0.2 equivalent and was complete at pH 4.7-4.8 with 2.5-2.6 equivalents. Dissolution of the hydrous precipitate at pH 9.6-9.7 after addition of 4.0-4.2 equivalents of alkali was considered evidence for the formation of the species [Ga(OH)J-in solution. Lacroix (8) obtained precipitation from 0.007 M gallium(II1) chloride solution at ca. pH 3.2 and dissolution of the hydrous oxide over a broad range above pH 6.Hydrolysis studies on gallium(II1) salt solutions appear limited to those of Fricke and his coworkers (2, 3). A preliminary measurement (2) of hydrogenion concentration showing 0.1875 N gallium(II1) chloride solution to be 32.9 per cent hydrolyzed was followed (3) by similar measurements as functions of

Separation and Recovery of Valuable Elements from Spent CIGS Materials

“…In particular, the precipitation rates of indium and gallium ions reach 99.60% and 99.51% at pH 3.5, and the copper ion precipitation rate is only 2%, achieving indium and gallium separation from copper. Furthermore, the hydrolysis reactions of indium and gallium ions in the precipitation process are as follows: , The precipitation product of indium and gallium was roasted at 800 °C to obtain mixed oxides, and their XRD patterns are shown in Figure (d). The main phases are In 2 O 3 , Ga 2 O 3 , and x Ga 2 O 3 · y In 2 O 3 , indicating that the precipitation reaction of indium and gallium ions occurs.…”

“…In particular, the precipitation rates of indium and gallium ions reach 99.60% and 99.51% at pH 3.5, and the copper ion precipitation rate is only 2%, achieving indium and gallium separation from copper. Furthermore, the hydrolysis reactions of indium and gallium ions in the precipitation process are as follows: 34,35…”