Method of producing iron oxide red through iron sulfate hydrothermal process

Abstract

The invention relates to a method of producing iron oxide red through an iron sulfate hydrothermal process. The method of producing iron oxide red through the iron sulfate hydrothermal process comprises the steps of dissolving iron sulfate in water to prepare an Fe<2+> solution with the concentration of 0.1 to 1 mol / L, slowly dripping ammonia water under the condition of full agitation, regulating the pH value of the solution to 8 to 10, feeding oxygen or air, performing room-temperature reaction for 1 to 24h under agitation to obtain Fe(OH)3 colloids and filtrate, preparing the Fe(OH)3 colloids into a colloid solution with the total iron concentration being 0.5 to 2 mol / L, adding iron oxide red crystal seeds and heptahydrate iron sulfate, performing hydrothermal reaction for 0.5 to 3h at 200 to 300 DEG C in a high-pressure kettle, then performing filtration, washing, drying and crushing to obtain the iron oxide red, performing ammonia precipitation, and then recovering ammonium sulfate through evaporative crystallization of filtrate or preparing ammonia water through stripping. By preparing the iron oxide red by using the iron sulfate hydrothermal process, the process is simple, and the production cost of the iron oxide red is reduced and the environmental and economic benefits are great.

Description

technical field [0001] The invention belongs to the field of preparation of inorganic powder materials, and in particular relates to a method for producing iron oxide red by using ferrous sulfate. Background technique [0002] Ferrous sulfate mainly comes from the production of titanium dioxide. Titanium dioxide (commonly known as titanium dioxide) is currently the most important white pigment in the world. Its production processes mainly include sulfuric acid method and chlorination method. China's titanium dioxide output reached 2.466 million tons in 2014, and most of China's titanium dioxide production uses the sulfuric acid method. The sulfuric acid method is used to produce titanium dioxide. For every ton of titanium dioxide produced, 3.5 to 4 tons of ferrous sulfate must be discharged. China discharged about 9 million tons of ferrous sulfate in 2014. Such a large amount of ferrous sulfate (FeSO 4 ·7H 2 O) If it is not comprehensively utilized, it will pollute the env...

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Problems solved by technology

The Chinese patent with the publication number CN1903735A discloses a method for producing iron oxide red by ferrous sulfate hydrothermal method, which is a hydrothermal reaction under oxygen pressure, and the process reaction pressure is high (1.2-2.2MPa), requiring excessive Ammonia water has large alkali consumption and high cost of raw materials; the pH value control at the end of the reaction is unstable, the oxidation of ferrous ions in the reaction solution is incomplete, and the quality of the red iron oxide product is unstable; the process of multi-stage oxidation reaction is complicated and the production cost is high