Solubility in the system NiCl2–ZnCl2–H3BO3–H2O at 15, 20 and 25 °C

Abstract

Solubility in the system NiCl₂–ZnCl₂–H₃BO₃–H₂O for a limited concentration range of ZnCl₂(up to 13.5 wt %) has been investigated at 15, 20 and 25 °C. In the ternary system NiCl₂–ZnCl₂–H₂O no formation of solid solutions takes place, contrary to similar systems of sulphates or nitrates of both cations: only nickel chloride hexahydrate, NiCl₂· 6H₂O, has been found as the coexisting solid phase in the mentioned concetration and temperature range. The ternary system NiCl₂–H₃BO₃–H₂O belongs to a simple system in which each of both components crystallizes in a pure from form mixed saturated solutions, with the exception of eutonic solutions, with which both solid components coexist together. In the quaternary system, the solubility of NiCl₂ decreases slightly with increasing content of ZnCl₂ and H₃BO₃. Similar trends have been observed for the solubility of H₃BO₃ dependent on the content of NiCl₂ or ZnCl₂, respectively. The solubility dependence of the crystallizing component on the content of other components (in wt % and mol kg^–1) and on the temperature have been expressed numerically.