阅读说明：本技术 利用钛白粉盐酸法副产物制备磁铁粉的方法 (Method for preparing magnet powder by using titanium dioxide hydrochloric acid method byproduct ) 是由 黄齐茂 胡骆兴 刘衡 于 2021-10-15 设计创作，主要内容包括：本发明公开了利用钛白粉盐酸法副产物制备磁铁粉的方法,将钛白粉盐酸法产生的固体氯化亚铁副产物与去离子水在反应釜A中混合,搅拌升温至75-85℃；将生石灰粉末、分散剂分批次加入反应釜A中,保持温度并用空气泵通入空气进行氧化；另将一份固体氯化亚铁副产物与去离子水在反应釜B中搅拌混合,加入生石灰常温下搅拌5-15min后将反应釜B中物料加入反应釜A,保持75-85℃恒温搅拌30-60min；趁热压滤,滤饼干燥,再经过研磨即可得到四氧化三铁磁铁粉；本发明通过钛白粉盐酸法产生的氯化亚铁固废、氧化钙为原料,通过工艺优化,避免胶体包裹及氧化不完全的现象,解决了大剂量、高浓度工业制备Fe-(3)O-(4)磁铁粉的难题。(The invention discloses a method for preparing magnet powder by using titanium dioxide hydrochloric acid method byproducts, which comprises the steps of mixing solid ferrous chloride byproducts generated by the titanium dioxide hydrochloric acid method with deionized water in a reaction kettle A, stirring and heating to 75-85 ℃; adding quicklime powder and a dispersing agent into a reaction kettle A in batches, keeping the temperature, and introducing air by using an air pump for oxidation; stirring and mixing a part of solid ferrous chloride byproduct and deionized water in a reaction kettle B, adding quicklime, stirring for 5-15min at normal temperature, adding the materials in the reaction kettle B into the reaction kettle A, and stirring for 30-60min at a constant temperature of 75-85 ℃; filter pressing is carried out while the mixture is hot, filter cakes are dried, and then the mixture is ground to obtain ferroferric oxide magnetic iron powder; the invention uses ferrous chloride solid waste and calcium oxide generated by titanium dioxide hydrochloric acid method as raw materials, avoids colloid wrapping and incomplete oxidation through process optimization, and solves the problem of industrially preparing Fe with large dose and high concentration 3 O 4 The problem of magnet powder.)

1. The method for preparing the magnet powder by utilizing the titanium dioxide hydrochloric acid method byproduct is characterized by comprising the following steps of:

(1) mixing a solid ferrous chloride byproduct generated by a titanium dioxide hydrochloric acid method with deionized water in a reaction kettle A, stirring and heating to 75-85 ℃;

(2) adding quicklime powder and a dispersing agent into a reaction kettle A in batches, keeping the temperature, and introducing air by using an air pump for oxidation;

(3) stirring and mixing a part of solid ferrous chloride byproduct and deionized water in a reaction kettle B, adding quicklime, stirring for 5-15min at normal temperature, adding the materials in the reaction kettle B into the reaction kettle A, and stirring for 30-60min at a constant temperature of 75-85 ℃;

(4) and (4) carrying out filter pressing while the mixture is hot, drying a filter cake, and grinding to obtain the ferroferric oxide magnetic iron powder.

2. The method of claim 1, wherein the solid ferrous chloride byproduct is obtained from the titanium dioxide hydrochloric acid process:

specifically, the method comprises the steps of heating a reaction product of titanium concentrate and hydrochloric acid, filtering the obtained filtrate, and cooling and crystallizing the filtrate to obtain a precipitate.

3. The method for preparing magnet powder using titanium dioxide by-product of hydrochloric acid process as claimed in claim 1, wherein the concentration of ferrous chloride in reaction vessel B of reaction vessels a and 3 of step (1) is 4.5-5.5 mol/L.

4. The method for preparing magnet powder using titanium dioxide hydrochloric acid by-product as claimed in claim 1, wherein the dispersant in step (2) is one or a mixture of poly ferric chloride, poly aluminum chloride, and aluminum-iron co-polymer flocculant.

5. The method for preparing magnet powder using titanium dioxide by-product of hydrochloric acid process as claimed in claim 1, wherein the amount of dispersant added in the reaction vessel a in the step (2) is 16-20kg per ton of the mixed solution; adding into four batches, wherein each time interval is 1.2-1.8 h.

6. The method for preparing magnet powder by using titanium dioxide hydrochloric acid by-product as claimed in claim 1, wherein the total amount of quicklime powder added to the reaction kettle A in the step (2) is 110-140Kg per ton of the mixed solution; adding into four batches, wherein each time interval is 1.2-1.8 h.

7. The method for preparing magnet powder by using titanium dioxide hydrochloric acid by-products as claimed in claim 1, wherein the total amount of quicklime powder added to the reaction vessel B in the step (3) is 110-140Kg per ton of the mixed solution.

8. The method for preparing magnet powder using titanium dioxide by-product produced by hydrochloric acid process as claimed in claim 1, wherein the oxidation is continued for 2 hours after the completion of the charging in step (2).

9. The method for preparing magnet powder using titanium dioxide hydrochloric acid by-product as claimed in claim 1, wherein the molar ratio of ferrous chloride in the reaction vessel B to ferrous chloride in the reaction vessel a in step (3) is 1: 2.

10. the method for preparing magnet powder using titanium dioxide by-product produced by hydrochloric acid process as claimed in claim 1, wherein the drying temperature in step (4) is 120 ℃ and the drying time is 10-12 hours.

Technical Field

The invention particularly relates to a method for preparing magnet powder by using a titanium dioxide hydrochloric acid method byproduct.

Background

The method for preparing magnetic powder in laboratory is to use low-concentration FeSO₄The solution reacts with NaOH, and the reaction concentration is low, the reaction amount is small, and the reaction is also in the level of dilute solution (0.05-0.2mol/L) of a laboratory test tube, because with FeSO₄The concentration is increased, and the generated ferrous hydroxide is precipitatedThe Fe is coated by colloid formed by precipitation²⁺The oxidation is inhibited, the incomplete oxidation or the oxidation is stopped, and the magnetic powder prepared under high concentration can not be amplified and industrialized. Industrial utilization of solid wastes for preparing Fe₃O₄Magnetic powder is not reported.

CN202110906536.X discloses a method for directly preparing titanium pigment from titanium concentrate and concentrated hydrochloric acid, which comprises adding crystal modifier, hydrolyzing the titanium concentrate with concentrated hydrochloric acid at 140 deg.C under high temperature and high pressure, cooling, and filtering to obtain titanium pigment. However, the method is accompanied by the generation of a large amount of solid ferrous chloride by-products, and the impurity content of the ferrous chloride by-products is high, if the ferrous chloride is not converted, the ferrous chloride by-products can only be used as solid waste, so that the method not only pollutes the environment, but also causes economic loss of the process route.

Disclosure of Invention

The invention aims to provide a method for preparing Fe by utilizing ferrous chloride-containing solid waste₃O₄The method of the magnet powder is particularly directed at the solid ferrous chloride byproduct generated by the titanium dioxide hydrochloric acid method, so that the process for preparing the titanium dioxide by the titanium concentrate is more complete, environment-friendly and economical.

In order to achieve the purpose, the technical scheme is as follows:

the method for preparing the magnet powder by utilizing the titanium dioxide hydrochloric acid method byproduct comprises the following steps:

(1) mixing a solid ferrous chloride byproduct generated by a titanium dioxide hydrochloric acid method with deionized water in a reaction kettle A, stirring and heating to 75-85 ℃;

(2) adding quicklime powder and a dispersing agent into a reaction kettle A in batches, keeping the temperature, and introducing air by using an air pump for oxidation;

(3) stirring and mixing a part of solid ferrous chloride byproduct and deionized water in a reaction kettle B, adding quicklime, stirring for 5-15min at normal temperature, adding the materials in the reaction kettle B into the reaction kettle A, and stirring for 30-60min at a constant temperature of 75-85 ℃;

(4) and (4) carrying out filter pressing while the mixture is hot, drying a filter cake, and grinding to obtain the ferroferric oxide magnetic iron powder.

According to the scheme, the solid ferrous chloride byproduct is obtained by a titanium dioxide hydrochloric acid method:

specifically, the method comprises the steps of heating a reaction product of titanium concentrate and hydrochloric acid, filtering the obtained filtrate, and cooling and crystallizing the filtrate to obtain a precipitate.

According to the scheme, the concentration of ferrous chloride in the reaction kettles A and B in the step (1) and the step (3) is 4.5-5.5 mol/L.

According to the scheme, the dispersing agent in the step (2) is one or a mixture of polyferric chloride, polyaluminium chloride and an aluminum-iron copolymerization composite flocculating agent.

According to the scheme, the adding amount of the dispersing agent in the reaction kettle A in the step (2) is 16-20kg per ton of the mixed solution; adding into four batches, wherein each time interval is 1.2-1.8 h.

According to the scheme, the total adding amount of the quicklime powder in the reaction kettle A in the step (2) is 110-140Kg per ton of the mixed solution; adding into four batches, wherein each time interval is 1.2-1.8 h.

According to the scheme, the total adding amount of the quicklime powder in the reaction kettle B in the step (3) is 110-140Kg per ton of the mixed solution.

According to the scheme, after the feeding in the step (2) is finished, the temperature is kept and the oxidation is continued for 2 h.

According to the scheme, the molar ratio of the ferrous chloride in the reaction kettle B to the ferrous chloride in the reaction kettle A in the step (3) is 1: 2.

according to the scheme, the drying temperature in the step (4) is 120 ℃, and the drying time is 10-12 h.

In the scheme, double-kettle separated reaction is adopted, and Fe in the reaction solution can be removed from the reaction solution in comparison with the reaction solution in a conventional unified kettle²⁺/Fe³⁺And in the monitoring and regulating link of the concentration ratio, two kettles are adopted to separately react without mutual interference. According to the scheme, the quicklime and the dispersing agent are added in batches, compared with the traditional method of adding the alkaline agent at one time, the problem of precipitation and wrapping caused by overhigh concentration can be avoided, and low-concentration Fe (OH) is locally formed in the process of gradually adding the quicklime₂The oxidation is gradually carried out, and the addition of the dispersing agent further destroys the colloid, thereby avoiding the difficult problem of forming colloid package to prevent oxidation.

Compared with the prior art, the invention has the following beneficial effects:

the invention takes ferrous chloride solid waste and calcium oxide as raw materials and adopts the technical proposal thatThe process is optimized, the phenomena of colloid wrapping and incomplete oxidation are avoided, and the problem of industrially preparing Fe with large dose and high concentration is solved₃O₄The difficulty of magnetic powder.

The process is simple, and cheap solid waste is converted into valuable Fe₃O₄The magnetic powder improves the new process route of the titanium dioxide hydrochloric acid method, and the industrialization and industrialization prospects of the titanium dioxide hydrochloric acid method are wider.

Detailed Description

The following examples further illustrate the technical solutions of the present invention, but should not be construed as limiting the scope of the present invention.

The invention provides a method for preparing magnet powder by utilizing ferrous chloride-containing solid waste, in particular to a solid ferrous chloride byproduct generated by a titanium dioxide hydrochloric acid method, which comprises the following specific steps:

(1) mixing a solid ferrous chloride byproduct generated by a titanium dioxide hydrochloric acid method with deionized water in a reaction kettle A, stirring and heating to 75-85 ℃; wherein the concentration of the ferrous chloride is 4.5-5.5 mol/L;

(2) adding quicklime powder and a dispersing agent into a reaction kettle A in batches, keeping the temperature, and introducing air by using an air pump to oxidize for 2 hours; wherein the addition amount of the dispersing agent is 16-20kg per ton of the mixed solution, and the dispersing agent is added in four batches, and the time interval of each time is 1.2-1.8 h; the total adding amount of the quicklime powder is 110-140Kg per ton of the mixed solution, and the quicklime powder is added in four batches, wherein the time interval of each time is 1.2-1.8 h; the dispersing agent is one or a mixture of polyferric chloride, polyaluminium chloride and an aluminum-iron copolymerization composite flocculating agent;

(3) stirring and mixing a part of solid ferrous chloride byproduct and deionized water in a reaction kettle B, adding quicklime, stirring for 5-15min at normal temperature, adding the materials in the reaction kettle B into the reaction kettle A, and stirring for 30-60min at a constant temperature of 75-85 ℃; wherein the concentration of the ferrous chloride in the reaction kettle B is 4.5-5.5mol/L, and the molar ratio of the ferrous chloride in the reaction kettle B to the ferrous chloride in the reaction kettle A is 1: 2; the total adding amount of the quicklime powder in the reaction kettle B is 140Kg of 110-;

(4) and (3) carrying out filter pressing while the mixture is hot, wherein the drying temperature of a filter cake is 120 ℃, the drying time is 10-12h, and grinding to obtain the ferroferric oxide magnetic iron powder.

The method is suitable for common solid ferrous chloride byproducts, but has better effect on the solid ferrous chloride byproduct generated by the titanium dioxide hydrochloric acid method. The invention relates to a situation that a titanium dioxide hydrochloric acid method generates a solid ferrous chloride byproduct, taking an artificial rutile preparation method as an example, and comprising the following steps:

mixing the titanium concentrate with a crystallization improvement auxiliary agent, and uniformly mixing to form a mixture A; adding the mixture A into a hydrochloric acid solution to form a mixture B; adding the mixture B into a reaction kettle, heating to 130-150 ℃, and filtering the obtained product to obtain filter residue and filtrate; acid washing, water washing and drying the filter residue to obtain artificial rutile; the obtained filtrate was put into a cooling tank to be crystallized and precipitated to obtain a solid ferrous chloride by-product, which was used in the following examples.

Example 1

Weighing 12kg of the byproduct ferrous chloride solid waste in the new process of the titanium dioxide hydrochloric acid method in a 50L reaction kettle, adding 12L of deionized water, stirring and heating to 80 ℃. Weighing four parts of 0.85kg of quicklime powder and 0.12kg of polyferric chloride, adding one part of the quicklime powder and one part of the polyferric chloride into a reaction kettle at an interval of 1.5h, keeping the constant temperature of 80 ℃ and stirring, introducing air by using an air pump for oxidation, and continuing to oxidize for 2h after four parts of quicklime are added. And then 6kg of the byproduct ferrous chloride solid waste in the new process of the titanium dioxide hydrochloric acid method is taken to be put into another 20L reaction kettle, 6kg of deionized water is added, stirring and dissolving are carried out at normal temperature, 1.7kg of quicklime is weighed, slowly added, and then stirring is carried out continuously for 10 min. And after stirring, adding slurry in a 20L reaction kettle into a 50L reaction kettle, stirring at the constant temperature of 80 ℃ for 45min, filtering the mixed solution by adopting positive pressure filter pressing, then putting a filter cake into a 120 ℃ drying oven, drying for 11h, taking out, and grinding to obtain a black magnetic ferroferric oxide product, wherein the yield is 95%.

Example 2

Weighing 12kg of the byproduct ferrous chloride solid waste in the new process of the titanium dioxide hydrochloric acid method, namely the ferrous chloride solid waste, into a 50L reaction kettle, adding 10L of deionized water, stirring and heating to 75 ℃. Weighing four parts of 0.85kg of quicklime powder and 0.12kg of polyaluminium chloride, adding one part into a reaction kettle at an interval of 1.2h, keeping the constant temperature of 75 ℃ and stirring, introducing air by using an air pump for oxidation, and continuing to oxidize for 2h after four parts of quicklime are added. And then 6kg of the byproduct ferrous chloride solid waste in the new process of the titanium dioxide hydrochloric acid method is taken to be put into another 20L reaction kettle, 5kg of deionized water is added, stirring and dissolving are carried out at normal temperature, 1.7kg of quicklime is weighed and slowly added, and then stirring is carried out continuously for 5 min. And after stirring, adding slurry in a 20L reaction kettle into a 50L reaction kettle, stirring at the constant temperature of 75 ℃ for 45min, filtering the mixed solution by adopting positive pressure filter pressing, then putting a filter cake into a 120 ℃ drying oven, drying for 10h, taking out, and grinding to obtain a black magnetic ferroferric oxide product, wherein the yield is 92%.

Example 3

Weighing 12kg of the byproduct ferrous chloride solid waste in the new process of the titanium dioxide hydrochloric acid method, namely the ferrous chloride solid waste, into a 50L reaction kettle, adding 14L of deionized water, stirring and heating to 85 ℃. Weighing four parts of 0.85kg of quicklime powder and 0.12kg of aluminum-iron copolymerization composite flocculant, adding one part into a reaction kettle at an interval of 1.8h, keeping constant temperature of 85 ℃ and stirring, introducing air by using an air pump for oxidation, and continuing to oxidize for 2h after four parts of quicklime are added. And then 6kg of the byproduct ferrous chloride solid waste in the new process of the titanium dioxide hydrochloric acid method is taken to be put into another 20L reaction kettle, 7kg of deionized water is added, stirring and dissolving are carried out at normal temperature, 1.7kg of quicklime is weighed and slowly added, and then stirring is carried out continuously for 15 min. And after stirring, adding slurry in a 20L reaction kettle into a 50L reaction kettle, stirring at the constant temperature of 85 ℃ for 45min, filtering the mixed solution by adopting positive pressure filter pressing, then putting a filter cake into a 120 ℃ drying oven, drying for 12h, taking out, and grinding to obtain a black magnetic ferroferric oxide product, wherein the yield is 94%.