Fine-Dispersed Iron (III) Oxyhydroxides Synthesis: Carbamide Precipitation

Abstract

The conditions of carbamide precipitation synthesis of fine-dispersed iron (III) oxyhidroxides from iron (III) sulphate and nitrate solutions were found out. In order to determine the necessary precipitant amount potentiometric precipitation titration of iron (III) sulphate and nitrate solutions with ammonia and hydrolyzed carbamide solutions were carried out. The results of these researches are expounded. The results of the investigations of precipitates properties, which were obtained from different initial solutions and characterized by different aging time, such as the precipitates phase composition and filtration properties, were presented. It was found, that the precipitation process from iron nitrate solution has less material consumption. Obtained precipitates have nanometer dispersity and the best filtration properties (less precipitant resistivity). The properties and composition changes depended on the aging time were revealed. It was determined that the filtration, physical and chemical properties of precipitates, which were obtained from the iron nitrate solution, are almost independent of the aging time. According to the results of X-ray analysis the crystal size is about 40 nm.