阅读说明：本技术 一种氯化法钛白粉副产盐酸制备钛酸钡的方法 (Method for preparing barium titanate from hydrochloric acid byproduct of titanium dioxide produced by chlorination process ) 是由 唐红梅 邓科 于 2019-03-06 设计创作，主要内容包括：本发明涉及一种钛酸钡的制备方法,具体地说是利用含有TiOCl<Sub>2</Sub>的氯化法钛白粉副产盐酸与工业碳酸钡进行酸解反应,控制酸解液中的Ba/Ti比和pH值,再将其滴加到热碱溶液中进行中和反应,反应完成后经过陈化、过滤、洗涤、煅烧后即可得到BaTiO<Sub>3</Sub>成品。(The invention relates to a preparation method of barium titanate, in particular to a barium titanate-containing barium titanate 2 The hydrochloric acid byproduct of titanium dioxide produced by chlorination process and industrial barium carbonate are subjected to acidolysis reaction, the Ba/Ti ratio and the pH value in acidolysis solution are controlled, then the obtained product is dripped into hot alkali solution for neutralization reaction, and after the reaction is finished, the obtained product is aged, filtered, washed and calcined to obtain BaTiO 3 And (5) finishing.)

1. A method for preparing barium titanate is characterized in that TiOCl is contained₂Performing acidolysis reaction on hydrochloric acid as a byproduct of titanium dioxide produced by chlorination process and industrial barium carbonate, filtering to separate out acid insoluble substances, adjusting the pH value of acidolysis solution, dropwise adding the acidolysis solution into hot alkali solution for neutralization reaction, and aging, filtering, washing and calcining the solution after the reaction is finished to obtain BaTiO₃And (5) finishing.

2. The method as claimed in claim 1, wherein the hydrochloric acid used for the acidolysis reaction with industrial barium carbonate is TiOCl-containing hydrochloric acid₂The by-product hydrochloric acid of titanium dioxide produced by the chlorination process.

3. The method as claimed in claim 1, wherein the acidolysis reaction temperature of the industrial barium carbonate is 60 ± 5 ℃.

4. The method as claimed in claim 1, wherein the Ba/Ti ratio in the solution after the acid hydrolysis is controlled within a range of 1.0 to 1.05.

5. The method as claimed in claim 1, wherein the pH of the solution after acidolysis is adjusted to 4.5-6.0, and the pH regulator is selected from NaOH and Na₂CO₃、NaHCO₃One or more of (a).

6. The method of claim 1, wherein polyethylene glycol is added to the barium-titanium mixture as a dispersant.

7. The method of claim 1, wherein the barium-titanium mixed solution is added dropwise to the NaOH alkaline solution, wherein the concentration of the NaOH alkaline solution is 2 mol/L; wherein the barium-titanium mixed solution is kept at a temperature not lower than 70 ℃, the temperature of NaOH alkaline solution is 85-95 ℃, and the solution is reacted for 2 hours under the condition that the pH value of the solution is not lower than 13.5 after the dropwise addition is finished.

8. The method according to claim 1, wherein the reaction mixture is aged for 1.5-2 hours after the neutralization reaction.

9. The method of claim 1, wherein the barium titanate precipitate separated after aging is washed twice, wherein pure water is used for the washing, and absolute ethanol is used for the washing; wherein, the primary washing water is returned to the industrial barium carbonate ore grinding process to be used as water required by ore pulp preparation, and the secondary washing liquid is recycled after ethanol is recovered.

Technical Field

The invention relates to a production method for preparing barium titanate, belonging to the field of inorganic chemical industry. In particular by using a composition containing TiOCl₂The hydrochloric acid byproduct of titanium dioxide produced by chlorination process and industrial barium carbonate are subjected to acidolysis reaction, the Ba/Ti ratio and the pH value in acidolysis solution are controlled, then the obtained product is dripped into hot alkali solution for neutralization reaction, and after the reaction is finished, the obtained product is aged, filtered, washed and calcined to obtain BaTiO₃And (5) finishing.

Background

In the production process of titanium dioxide by a chlorination method, the tail gas washing waste acid of the chlorination process comprises two types: one is HCl with a hydrochloric acid concentration of about 20% and contains TiOCl₂The concentration is about 10.2 percent; another is HCl, TiOCl, with a hydrochloric acid concentration of about 28%₂The concentration is about 1.2%. In the use of such compositions containing TiOCl₂Hydrochloric acid of impurities, TiOCl₂Hydrolysis reaction can be carried out to separate out TiO along with the reduction of the concentration of free hydrochloric acid₂This hydrolytically precipitated fine TiO particle₂The impurities exist in the reaction system as solid phase, so that the application field of the hydrochloric acid is greatly limited.

In the aspect of utilizing hydrochloric acid as a byproduct of titanium dioxide produced by a chlorination process, a plurality of utilization methods are developed by a plurality of researchers according to the unique characteristics of the hydrochloric acid, some methods are used for coating the titanium dioxide, some methods are used for purifying the hydrochloric acid by membrane separation, and other methods are directly added with alkaline substances for neutralization. However, in general, the problems of low resource utilization efficiency and poor economy exist in the utilization of the hydrochloric acid as the byproduct of titanium dioxide produced by the chlorination process at present.

On the other hand, barium titanate is used as a main raw material for manufacturing electronic ceramics, and compared with capacitors made of other materials, barium titanate ceramic capacitors have the advantages of small volume, large capacity, high frequency, strong reliability and low cost, and are widely applied to large-scale integrated circuits. The aqueous phase synthesis method adopted by barium titanate powder firstly mixes TiCl₄Partial hydrolysis to give TiOCl₂Aqueous solution, then TiOCl₂Aqueous solution and BaCl₂Mixing the solution according to a certain proportion to prepare barium-titanium mixed solution, and then reacting the barium-titanium mixed solution with NaOH solution to obtain BaTiO₃And (3) powder.

Therefore, in order to efficiently utilize TiOCl contained in the production process of titanium dioxide by chlorination process₂The invention combines the aqueous phase method with BaTiO₃The production process comprises the steps of utilizing hydrochloric acid which is a byproduct of titanium dioxide produced by a chlorination method to perform acidolysis on industrial barium carbonate, and reacting the hydrochloric acid with the barium carbonate to obtain BaCl₂With TiOCl in hydrochloric acid₂As the mixed solution of barium and titanium, strictly controlling the Ba/Ti ratio and the pH value in the mixed solution of barium and titanium, dripping the mixed solution of barium and titanium into hot alkali solution for neutralization reaction, and obtaining BaTiO after aging, filtering, washing and calcining the mixture after the reaction is finished₃And (5) finishing.

The main chemical reaction equation in the barium carbonate acidolysis process is as follows:

BaCO₃+2HCl=BaCl₂+ H₂O+CO₂

BaCl₂and TiOCl₂Formation of BaTiO in strongly alkaline solutions₃The chemical reaction equation of (a) is:

TiOCl₂+ BaCl₂+4NaOH= BaTiO₃↓+4NaCl+2H₂O 。

disclosure of Invention

The invention aims to utilize a catalyst containing TiOCl₂The hydrochloric acid byproduct of titanium dioxide produced by the chlorination method is subjected to acidolysis reaction with industrial barium carbonate, and TiOCl contained in the hydrochloric acid byproduct is utilized₂BaCl obtained by acidolysis reaction₂The Ba/Ti ratio and the pH value in the mixed solution of the barium and the titanium are controlled, the mixed solution of the barium and the titanium is added into a hot alkali solution dropwise for neutralization reaction, and after the reaction is finished, the BaTiO is obtained by aging, filtering, washing and calcining₃And (5) finishing.

The purpose of the invention is realized as follows:

measuring a certain amount of TiOCl₂Adding hydrochloric acid as a byproduct of titanium white chloride into an acidolysis reaction kettle, and simultaneously adding TiOCl into the hydrochloric acid₂Adding metered industrial barium carbonate slurry according to the Ba/Ti ratio of 1.0-1.05 in the acidolysis solution, opening a tail gas fan and closing a feed valve of the acidolysis reaction kettle; heating the acidolysis reaction kettle, keeping the acidolysis temperature at 60 +/-5 ℃, and starting stirring to ensure that barium carbonate is fully contacted with hydrochloric acid for reaction; adding Na into the reaction kettle after reacting for 2h₂CO₃Adjusting the pH value of the solution to be within the range of 4.5-6; filtering to separate insoluble impurities from acidolysis solution, adding polyethylene glycol with a content of about 1% into acidolysis solution, heating to above 70 deg.C to change the dispersion state of precipitate, prevent association between precipitate particles, and reduce generation of aggregate to form uniformly dispersed BaTiO₃And (5) finishing. Meanwhile, a certain amount of 2mol/L NaOH solution is measured into a neutralization reaction kettle and heated to 90 +/-5 ℃, the barium-titanium mixed solution added with polyethylene glycol is gradually added into the hot alkali solution of the neutralization reaction kettle in a dropwise adding mode under the condition of stirring, the solution is reacted for 2 hours under the condition that the pH value is not lower than 13.5 after the dropwise adding is finished, then the solution is transferred into an aging kettle to be gradually cooled and aged for 1.5-2 hours and then filtered, a filter cake is washed twice, pure water is adopted for one-time washing, and absolute ethyl alcohol is adopted for the second-time washing; wherein, the primary washing water is returned to the industrial barium carbonate ore grinding process to be used as water required by ore pulp preparation, and the secondary washing liquid is recycled after ethanol is recovered. The washed filter cake is finally calcinedThen BaTiO is obtained₃And (5) finishing.

The invention has the beneficial effects that:

by using a catalyst containing TiOCl₂The hydrochloric acid byproduct of titanium dioxide produced by the chlorination method is used for carrying out acidolysis reaction on barium carbonate, and the barium carbonate is formed into soluble BaCl₂And TiOCl in hydrochloric acid byproduct of titanium dioxide produced by chlorination process₂Mixing to obtain barium-titanium mixed solution, and dripping the barium-titanium mixed solution into hot alkali solution to obtain BaTiO₃And (5) finishing. The technological process makes titanium element in hydrochloric acid as the by-product of titanium white production produced in chlorination process utilized in high added value, and makes full use of free acid in hydrochloric acid to hydrolyze barium carbonate to obtain BaCl₂To obtain BaTiO₃The barium source effectively realizes TiOCl in titanium dioxide byproduct hydrochloric acid by a chlorination method₂And the high-efficiency resource utilization of the free hydrochloric acid greatly improves the economical efficiency of the process.

Drawings

FIG. 1 is a schematic view of a process flow for preparing barium titanate from hydrochloric acid as a byproduct of titanium dioxide production by a chlorination process.

Detailed Description

The present invention is further described in detail with reference to the following examples, but the scope of the present invention is not limited to these examples.