KR-102963281-B1 - Method of production of ferrous sulfate

Abstract

A method for manufacturing ferrous sulfate is provided. The present invention is a method for producing ferrous sulfate by mixing an aqueous sulfuric acid solution with an iron-containing material, wherein the concentration of the aqueous sulfuric acid solution is 20 to 90% and the mixing ratio of the aqueous sulfuric acid solution to the iron-containing material is 0.2 to 0.5 by weight.

Inventors

• 조성구
• 이훈하
• 최광희

Assignees

• 주식회사 포스코
• 재단법인 포항산업과학연구원

Dates

Publication Date

20260511

Application Date

20221220

Claims (5)

1. A method for producing ferrous sulfate by mixing an aqueous sulfuric acid solution with an iron-containing material, A method for manufacturing ferrous sulfate, wherein the concentration of the above-mentioned aqueous sulfuric acid solution is 20 to 90%, the mixing ratio of the above-mentioned aqueous sulfuric acid solution to the above-mentioned iron-containing material is 0.2 to 0.4 by weight, and the above-mentioned aqueous sulfuric acid solution is semiconductor waste sulfuric acid.
2. A method for manufacturing ferrous sulfate according to claim 1, wherein the iron-containing material has an iron content of 50% or more by weight.
3. A method for producing ferrous sulfate according to claim 1, wherein the iron-containing material is one or more selected from the group comprising iron scrap, iron ore, mill scale, iron-containing dust, and iron-containing sludge.
4. A method for manufacturing ferrous sulfate, wherein the iron-containing sludge in claim 3 is steelmaking OG sludge.
5. delete

Description

Method of production of ferrous sulfate The present invention relates to a method for producing ferrous sulfate, and more specifically, to a method for producing ferrous sulfate that uses an iron-containing material and an aqueous sulfuric acid solution to omit the step of preparing an aqueous iron sulfate solution and obtain ferrous sulfate directly. Ferrous sulfate, widely used as a water treatment coagulant, is used to manufacture safe cement with improved problems related to various cancers and diseases by reducing hexavalent chromium in cement to trivalent chromium. Typically, ferrous sulfate is produced from iron sulfate solutions generated mainly during the manufacturing processes of other products, such as steel pickling and titanium dioxide production. Meanwhile, ferrous sulfate can be produced through the reaction of iron and sulfuric acid. Recently, significant interest has been focused on technologies that utilize various by-products and waste materials containing iron and sulfuric acid for resource recycling and cost reduction. In the steel industry, by-products containing large amounts of iron, such as high-iron dust and sludge, are generated not only in mill scale but also in processes like ironmaking and steelmaking. Furthermore, since the semiconductor industry generates large quantities of high-concentration waste sulfuric acid, utilizing these by-products to produce ferrous sulfate can achieve benefits such as reduced waste disposal costs and efficient resource utilization. In order to produce ferrous sulfate from the iron sulfate solution generated in the aforementioned steel pickling and titanium dioxide manufacturing processes, a crystallization process through evaporation or cooling is required, which has the disadvantage of requiring a large amount of energy and complex equipment. Furthermore, even when utilizing by-products or waste containing iron and sulfuric acid, using a general wet process results in the generation of iron sulfate solution and necessitates a crystallization process that is disadvantageous in terms of energy and equipment. In addition, a filtration process must be performed to separate the ferrous sulfate from the liquid after the crystallization process. Patent Document 1 presents a method for producing an aqueous iron sulfate solution by reacting steel mill desulfurization dust with a sulfuric acid solution using iron-containing byproducts, and such a wet process must undergo crystallization and filtration processes as mentioned above. To overcome these disadvantages, Patent Document 2 presents a method for producing ferrous sulfate by reacting an iron source with a sulfuric acid solution to produce an aqueous iron sulfate solution, and then adding concentrated sulfuric acid. However, while this method allows for the omission of the crystallization process, it has the disadvantage that the ferrous sulfate is produced in the form of a slurry mixed with the solution, so it still requires a filtration process. Additionally, since it requires concentrated sulfuric acid of 90 wt% or more, it has the disadvantage that it is difficult to produce ferrous sulfate using only waste sulfuric acid, which is usually generated at a concentration of 90 wt% or less. The present invention will be described below. The reaction between an iron-containing substance and sulfuric acid is an exothermic reaction, and when the two substances are mixed, a large amount of heat is generated, causing excess water that did not participate in the reaction to evaporate. However, if the amount of residual water after mixing and evaporation is small enough that an iron sulfate solution is not formed, ferrous sulfate is immediately produced in a solid form. In other words, the inventors have confirmed that ferrous sulfate in a solid form can be obtained immediately by appropriately controlling the heat of production from the reaction between the iron-containing substance and sulfuric acid and the amount of initial water, that is, the concentration of sulfuric acid, and thus present the present invention. The present invention is a method for producing ferrous sulfate by mixing an aqueous sulfuric acid solution with an iron-containing material, wherein the concentration of the aqueous sulfuric acid solution is 20 to 90% and the mixing ratio of the aqueous sulfuric acid solution to the iron-containing material is 0.2 to 0.5 by weight. First, in the present invention, the iron-containing material (iron source) refers to a material containing iron components, and includes not only iron-containing raw materials such as iron scrap and iron ore, but also various iron-containing by-products such as mill scale, iron-containing dust, and iron-containing sludge. It is preferable that the above iron-containing material contains at least 50% iron by weight, so as to minimize the reaction of other components with sulfuric acid to facilitate the production of ferrous sulfate. In this invention, the sulfuric ac