Method for producing iron oxide red by using ferrous sulfate as titanium dioxide byproduct

Abstract

The invention discloses a method for producing oxide red by using ferrous sulfate as a titanium dioxide byproduct. The method comprises the following process steps of: firstly, dissolving the ferrous sulfate as the titanium dioxide byproduct with water of which the temperature is 50-80DEG C at normal pressure to form an aqueous solution; then adding ammonia water into the aqueous solution; adjusting the pH value of the aqueous solution to 2.2-4.0; adding soluble fluoride into the aqueous solution; reacting at the temperature of 50-80DEG C and normal pressure for 20-60 minutes by stirring; and after the reaction time reaches, separating a precipitation to obtain a purified liquid, wherein the addition mount of the soluble fluoride is 0.3-10 percent of the mass of the ferrous sulfate as the titanium dioxide byproduct; secondly, condensing and crystallizing the purified liquid obtained in the first step to obtain a pure ferrous sulfate crystal; and thirdly, dehydrating the pure ferrous sulfate crystal obtained in the second step at the temperature of 200-350DEG C and normal pressure for 20-60 minutes and calcining the reacted product at the temperature of 800-900DEG C and normal pressure for 1-4h to obtain the iron oxide red.

Description

technical field [0001] The invention belongs to a production method of iron oxide red, in particular to a method for producing high-purity iron oxide red by using ferrous sulfate, a by-product of titanium dioxide. Background technique [0002] High-purity iron oxide red can not only be used as a pigment, but also can be used to prepare magnetic materials. Iron oxide pigments are very important inorganic color pigments, their products have minimal toxicity and are widely used. Among a series of iron oxide pigments, iron oxide red is the most widely used, it is the most stable compound among iron oxides, its chemical name is ferric oxide (Fe 2 o 3 ). The typical production methods of iron oxide red are: green vitriol calcination method, iron mud roasting method, pyrite slag method, etc. [0003] In the production process of titanium dioxide, a large amount of ferrous sulfate (namely green vitriol) will be produced. For every ton of titanium dioxide produced, about four ton...

AI Technical Summary

Problems solved by technology

Although this method is relatively simple in technology, it has the following problems: 1. When the pH of the solution is adjusted to 5-6, the hydrolysis of ferrous ions is serious, the viscosity of the solution increases, and it is difficult to filter; 2. Impurity magnesium in ferrous sulfate cannot be removed. clean, especially for raw materials with a high initial content of magnesium; 3. The patent only states that the purity of the finished iron oxide red product is >99.2%, and does not disclose the types of impurities that can be removed and the impurity content of the finished iron oxide red product. The content of magnesium in the medium is too high, so it cannot be used in the preparation of oxygen magnetic materials; 4. The products obtained by calcination at 550 ° C are not all α-Fe 2 o 3 form, mixed with a lot of β-Fe 2 o 3 , nor can it be used in the preparation of oxygen magnetic materials

Images