The purpose of the paper is to study the physical and chemical features of high-quality iron concentrate precipitation from nitric acid leaching solutions of low-grade copper-sulfide raw materials, and to obtain a highly profitable product which is suitable for direct processing at ferrous metallurgy enterprises. To conduct the experiments on obtaining impurity rich and depleted iron concentrate a hydrolytic precipitate containing 54.6% iron and numerous impurities obtained as a result of processing of nitric acid leaching solutions of rough copper sulfide concentrate from the Zhezkazgan deposit is used. Analytical studies of initial materials and resulting products of the processes under investigation are conducted using the modern certified methods including the x-ray spectral, x-ray phase, atomic absorption analysis, mass spectrometry method with inductively coupled plasma. We have obtained a high-quality iron concentrate containing minimal amounts of silicon, aluminum, phosphorus and sulfur as well as partial and generalized equations that give an idea of the influence of the studied factors on the indicators of the iron concentrate production process. The apparent activation energy of the process has been calculated - 46.77 kJ/mol. It probably indicates the presence of diffusion complications caused by the formation of solid products passivating the surface of the material being dissolved. The principal possibility of obtaining high-quality iron concentrate from processing poor copper-sulfide concentrate middlings of the Zhezkazgan deposit is shown. The mathematical processing of experimental data has resulted in the determination of equations that characterize the degree of influence of the studied factors on the process indicators. It is found out that the production process of the saleable iron concentrate proceeds in the mode of diffusion restrictions. It is the first time, when multivariate generalized dependencies are obtained for the process under consideration and their analytical transformations are performed. These methods can be used to study the analogous processing of similar metallurgical raw materials.
The Use of Methyl Ethyl Ketone in Nitric Acid Leaching Processes for Enhancement of Ag Recovery from Used X-ray Films
