AN IMPROVED PROCESS FOR THE HYDROTHERMAL PREPARATION OF NICKEL-ZINC FERRITE

摘要

A new process is developed to recover nickel in the form of a high value product from spent nickel catalyst. The catalyst is treated in chloride media to dissolve nickel and the solution is directly used to prepare nickel-zinc ferrite hydrothermally in ammoniacal medium. The process also avoids additional steps for purification and treatment of leach solution for making intermediate products like nickel salts or metal by evaporation / electrolysis which consumes higher energy. Very uniform nano size Ni-Zn ferrite with high magnetization value of 68.1 emu/g is prepared and reported in this patent. Ni-Zn ferrites are a group of technologically important materials that are used in the fabrication of magnetic, electronic and microwave devices.