阅读说明：本技术 钛白粉副产品亚铁母液制备聚合硫酸铁的方法 (Method for preparing polymeric ferric sulfate from ferrous mother liquor of titanium dioxide byproduct ) 是由 许志远 李中和 郭小七 张建军 李明元 刘土山 刘元元 于 2020-06-30 设计创作，主要内容包括：本发明提供钛白粉副产品亚铁母液制备聚合硫酸铁的方法,包括以下步骤：1)将钛白粉生产副产物硫酸亚铁配置成硫酸亚铁的浓度为600-650g/l,升温至70-85℃,用氢氧化钠溶液将硫酸亚铁溶液的pH提高到4-6,加入硫化亚铁粉末,在70-85℃下反应1-3小时；2)将反应结束后的溶液降温至40-45℃,加入絮凝剂后进行过滤,得到滤渣和硫酸亚铁滤液；3)对滤液进行酸化处理,得到pH值为1-2.5的混合液；4)强力搅拌条件下加入氧化剂,40-70℃反应1-3h,得到聚合硫酸铁。本发明制的聚合硫酸铁符合GB14591-2006水处理剂聚合硫酸铁要求,有效处理了钛白粉生产过程中的副产物,实现双赢。(The invention provides a method for preparing polymeric ferric sulfate from a ferrous mother liquor of a titanium dioxide byproduct, which comprises the following steps: 1) preparing a byproduct ferrous sulfate in titanium dioxide production into a ferrous sulfate solution with the concentration of 600-650g/l, heating to 70-85 ℃, increasing the pH value of the ferrous sulfate solution to 4-6 by using a sodium hydroxide solution, adding ferrous sulfide powder, and reacting for 1-3 hours at 70-85 ℃; 2) cooling the solution after the reaction to 40-45 ℃, adding a flocculating agent, and filtering to obtain filter residue and ferrous sulfate filtrate; 3) acidifying the filtrate to obtain a mixed solution with a pH value of 1-2.5; 4) adding an oxidant under the condition of strong stirring, and reacting for 1-3h at 40-70 ℃ to obtain the polymeric ferric sulfate. The polymeric ferric sulfate prepared by the invention meets the requirements of GB14591-2006 water treatment agent polymeric ferric sulfate, effectively treats byproducts in the production process of titanium dioxide and realizes win-win.)

1. The method for preparing polymeric ferric sulfate from the ferrous mother liquor of the titanium dioxide byproduct is characterized by comprising the following steps of:

1) removing impurities, namely adding ferrous sulfate which is a byproduct in titanium dioxide production into deionized water, preparing the concentration of the ferrous sulfate to be 600-650g/l, then heating to 70-85 ℃, increasing the pH value of a ferrous sulfate solution to 4-6 by using a sodium hydroxide solution, then adding ferrous sulfide powder, and reacting for 1-3 hours at 70-85 ℃;

2) performing flocculation filtration, namely cooling the solution after the reaction to 40-45 ℃, adding a flocculating agent, wherein the adding amount of the flocculating agent in each cubic ferrous sulfate solution is 0.5-1g, performing flocculation stirring for 20-60 minutes, then clarifying for 20-60 minutes, and then filtering to obtain filter residue and ferrous sulfate filtrate;

3) acidifying: acidizing the ferrous sulfate filtrate obtained in the step 2) by using a sulfuric acid aqueous solution to obtain a mixed solution with the pH value of 1-2.5;

4) and (3) oxidative polymerization: adding oxidant under strong stirring, reacting for 1-3h at 40-70 deg.C to obtain polymeric ferric sulfate product.

2. The method for preparing polymeric ferric sulfate from the ferrous titanium dioxide byproduct mother liquor as claimed in claim 1, wherein the flocculating agent is polymeric ferric sulfate, and the concentration of the solution prepared from the flocculating agent is 0.01-10% wt.

3. The method for preparing polymeric ferric sulfate from ferrous mother liquor as a byproduct of titanium dioxide according to claim 1, wherein the method is characterized in thatIn the step 4), the oxidant is Na₂S₂O₈Powder or hydrogen peroxide.

4. The method for preparing polymeric ferric sulfate from the ferrous mother liquor as a byproduct of titanium dioxide according to claim 1 or 3, wherein an oxidant Na is added₂S₂O₈Until the molar ratio of ferrous ions to persulfate in the solution is 1: 0.1 to 1.0.

5. The method for preparing polymeric ferric sulfate from the ferrous mother liquor as the byproduct of titanium dioxide according to claim 1 or 3, wherein the molar ratio of the ferrous sulfate in the mixed solution and the hydrogen peroxide in the hydrogen peroxide is 1: 0.5-0.8.

Technical Field

The invention belongs to the technical field of preparation of polymeric ferric sulfate, and particularly relates to a method for preparing polymeric ferric sulfate from a ferrous mother solution of a titanium dioxide byproduct.

Background

Polyferric sulfate (referred to as polyferric chloride for short) is the most widely used inorganic coagulant for industrial sewage and wastewater treatment in the world as well as polyaluminium chloride, and belongs to iron system and aluminum system respectively, and because polyferric sulfate has the effects of removing suspended matters in wastewater, COD and BOD, organic matters such as phenol and the like, other harmful impurities (such as sulfide, cyanide and partial phosphide) and heavy metals, the polyferric sulfate is widely used in wastewater treatment in a plurality of industries in China. But the production process of the polymeric ferric sulfate is complex and the production cost is higher.

In recent years, with the rapid increase of the production capacity of the Chinese titanium dioxide, the by-product ferrous sulfate produced by the titanium dioxide is increased sharply. Since the ferrous sulfate contains heavy metals such as lead, cadmium, chromium, manganese, nickel, etc., and dissolves in water to make the water color cloudy and affect the quality of the water, it needs to be properly preserved, and a large amount of land and management cost needs to be consumed. The polymeric ferric sulfate is prepared by using the ferrous sulfate which is a byproduct in the production of titanium dioxide, so that the production cost can be greatly reduced, and meanwhile, the byproduct in the production of titanium dioxide can be effectively treated, thereby realizing win-win.

Disclosure of Invention

The invention aims to provide a method for preparing polymeric ferric sulfate from a ferrous mother liquor of a titanium dioxide byproduct, so as to solve the problems in the background technology.

In order to achieve the purpose, the invention adopts the following technical scheme: the method for preparing polymeric ferric sulfate from the ferrous mother liquor of the titanium dioxide byproduct comprises the following steps:

1) removing impurities, namely adding ferrous sulfate which is a byproduct in titanium dioxide production into deionized water, preparing the concentration of the ferrous sulfate to be 600-650g/l, then heating to 70-85 ℃, increasing the pH value of a ferrous sulfate solution to 4-6 by using a sodium hydroxide solution, then adding ferrous sulfide powder, and reacting for 1-3 hours at 70-85 ℃;

2) performing flocculation filtration, namely cooling the solution after the reaction to 40-45 ℃, adding a flocculating agent, wherein the adding amount of the flocculating agent in each cubic ferrous sulfate solution is 0.5-1g, performing flocculation stirring for 20-60 minutes, then clarifying for 20-60 minutes, and then filtering to obtain filter residue and ferrous sulfate filtrate;

3) acidifying: acidizing the ferrous sulfate filtrate obtained in the step 2) by using a sulfuric acid aqueous solution to obtain a mixed solution with the pH value of 1-2.5;

4) and (3) oxidative polymerization: adding oxidant under strong stirring, reacting for 1-3h at 40-70 deg.C to obtain polymeric ferric sulfate product.

Further, in the step 2), the filter residue is sulfide of heavy metal ions such as cobalt, nickel, zinc, copper, lead, cadmium and the like.

Further, the flocculating agent is polymeric ferric sulfate, and the concentration of the solution prepared by the flocculating agent is 0.01-10% wt.

Further, in the step 4), the oxidant is Na₂S₂O₈Powder or hydrogen peroxide.

Further, adding an oxidant Na₂S₂O₈Until the molar ratio of ferrous ions to persulfate in the solution is 1: 0.1-1.0.

Further, adding an oxidant hydrogen peroxide into the mixed solution until the molar ratio of ferrous sulfate in the mixed solution to hydrogen peroxide in the hydrogen peroxide is 1: 0.5-0.8.

The method has the beneficial effects that ferrous sulfide is added to remove heavy metal ions such as cobalt, nickel, zinc, copper, lead, cadmium and the like, a pure ferrous sulfate solution is obtained through flocculation and filtration, and then the polymeric ferric sulfate is obtained through oxidative polymerization.

Detailed Description