Method for preparing iron oxide yellow pigment by using titanium white by-product of ferrous sulfate

Abstract

The invention relates to a method for preparing an iron oxide yellow pigment by using a titanium white by-product of ferrous sulfate. The preparation method comprises the steps of: refining of the ferrous sulfate, preparation of seed crystal, oxidation synthesis, filteration, water washing, drying and crushing; and the oxidation synthesis specifically comprises the processes of: putting ferrous sulfate yellow seed crystal into an oxidation reaction barrel, heating up to 60-90 DEG C and preserving the temperature, controlling the pH value of a whole reaction system to be 2.5-4, simultaneously adding a refined ferrous sulfate solution, and maintaining the concentration of iron vitriol of the whole reaction system to be 50-65g / L, wherein the whole oxidation reaction time is 80-120h. Because the pH value of the whole oxidation synthesis reaction system changes stably and particles in the reaction system are uniform in size, the prepared iron oxide yellow pigment has uniform particles and good hue.

Description

technical field [0001] The invention relates to a method for preparing iron oxide yellow pigment from titanium dioxide by-product ferrous sulfate. Background technique [0002] Titanium dioxide is a high-grade high-quality white pigment. At present, my country mainly adopts the sulfuric acid method to produce titanium dioxide, which produces about 4 tons of ferrous sulfate per ton of titanium dioxide. According to statistics, the output of titanium dioxide in 2009 reached 1.05 million tons, and the output of waste paraferrous sulfate reached 4.2 million tons. Such a large amount of waste by-products (waste by-product ferrous sulfate), if the original accumulation method is still used, the large site occupied and the impact on the environment will seriously restrict the development of the titanium dioxide industry. Although in the past there were also people who used titanium dioxide waste secondary ferrous sulfate as iron catalyst, water purifier, feed additive, soil impro...

AI Technical Summary

Problems solved by technology

In this method, ammonia gas or ammonia water is added to the oxidation tank, which will easily cause the pH value of the adding point to become alkaline instantly, and form ferrous hydroxide precipitation, making the particle size uneven, resulting in a darker pigment hue in the later stage, which cannot meet the market demand.