阅读说明：本技术 一种氯化法钛白粉副产盐酸联产氯化钡和陶瓷钛白的方法 (Method for co-producing barium chloride and ceramic titanium white by-product hydrochloric acid of chlorination-process titanium dioxide ) 是由 唐红梅 邓科 阳丽 高原 海萍 于 2019-02-21 设计创作，主要内容包括：本发明涉及一种联产氯化钡和陶瓷钛白(TiO<Sub>2</Sub>)的方法,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毒重石进行酸解反应,将毒重石矿中的Ba以及杂质Fe、Ca、Mg等金属元素以氯化盐的形式进入到溶液中；盐酸中的可溶性TiOCl<Sub>2</Sub>则随着酸解反应的进行其游离盐酸浓度的降低而发生水解反应析出TiO<Sub>2</Sub>,水解副产的盐酸又用于补充毒重石酸解反应消耗的盐酸。分离毒重石矿中含硅的酸不溶物与氯化法钛白粉副产盐酸中TiOCl<Sub>2</Sub>水解析出的TiO<Sub>2</Sub>,经过洗涤干燥后则可得到陶瓷钛白成品；酸解液中加入Ba(OH)<Sub>2</Sub>与H<Sub>2</Sub>C<Sub>2</Sub>O<Sub>4</Sub>进行两次中和,将其中Fe、Ca、Mg等杂质元素去除,净化后的溶液经过闪蒸提浓后冷冻结晶分离出水合BaCl<Sub>2</Sub>.2H<Sub>2</Sub>O并进行洗涤干燥则可得BaCl<Sub>2</Sub>成品。(The invention relates to a method for co-producing barium chloride and ceramic titanium dioxide (TiO) 2 ) In particular by means of a catalyst containing TiOCl 2 Performing acidolysis reaction on the hydrochloric acid byproduct of titanium dioxide and witherite, and introducing Ba in the witherite ore and metal elements such as impurities Fe, Ca, Mg and the like into the solution in the form of chloride; soluble TiOCl in hydrochloric acid 2 The concentration of free hydrochloric acid decreases with the progress of the acidolysis reaction, and the hydrolysis reaction proceeds to precipitate TiO 2 The hydrochloric acid as the by-product of hydrolysis is used to supplement the hydrochloric acid consumed by acidolysis reaction of witherite. Separating siliceous acid insoluble substance in witherite ore and TiOCl in hydrochloric acid as by-product of titanium dioxide produced by chlorination process 2 Hydrolyzed TiO 2 Washing and drying to obtain a ceramic titanium dioxide finished product; adding Ba (OH) into acidolysis solution 2 And H 2 C 2 O 4 Neutralizing twice to remove Fe, Ca, Mg and other impurity elements, flash evaporating to concentrate, freezing to crystallize and separate hydrated BaCl 2 .2H 2 Washing and drying the O to obtain BaCl 2 And (5) finishing.)

1. A method for coproducing barium chloride and ceramic titanium dioxide is characterized in that the titanium dioxide containing TiOCl is utilized₂The hydrochloric acid byproduct of titanium dioxide produced by chlorination process and witherite ore are subjected to acidolysis reaction, and the acid insoluble substance containing silicon and TiOCl in ore removal are filtered and separated₂Washing and drying the hydrolysate to obtain a ceramic titanium dioxide finished product; removing impurities from acidolysis solution to obtain purified BaCl₂Freezing and crystallizing the solution to separate BaCl₂.2H₂O, washing and drying to obtain BaCl₂And (5) finishing.

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

3. The method according to claim 1, wherein the acidolysis reaction temperature of the witherite ore is 85 ± 5 ℃.

4. The method as claimed in claim 1, wherein Ba (OH) is used for purifying the acidolysis solution₂Removing iron, magnesium and most calcium by chemical precipitation (pH value is controlled to be above 12.5), and recycling H₂C₂O₄The method for removing calcium by combining chemical precipitation and physical adsorption of activated carbon, wherein the temperature of two precipitation reactions is not lower than 80 ℃.

5. The method of claim 1, wherein the purified BaCl is purified of impurities₂The solution was adjusted to pH 7 using hydrochloric acid.

6. The method of claim 1, wherein the BaCl is present in the sample₂.2H₂And the washing water of O is used as the primary washing water of the insoluble substances in the acidolysis reaction, the condensed water obtained by flash evaporation is used as the secondary washing water, and the two washing waters are returned to the witherite ore treatment procedure to be used as the water required for preparing ore pulp for recycling.

7. The process according to claim 1, characterized in that the BaCl is isolated by freeze crystallization₂.2H₂And returning the residual liquid of O to the primary neutralization and impurity removal process for recycling.

Technical Field

The invention relates to a production method for co-producing barium chloride and ceramic titanium dioxide, belonging to the field of inorganic chemical industry. In particular by using a composition containing TiOCl₂The hydrochloric acid byproduct of titanium dioxide produced by the chlorination process is subjected to acidolysis reaction with the witherite ore, and the silicon dioxide acid insoluble substance and TiOCl in the hydrochloric acid byproduct are separated₂Hydrolysate TiO of₂Washing and drying twice to obtain a ceramic titanium dioxide product; the acidolysis is purified and the impurities are removed, and then the freezing crystallization, the washing and the drying are carried out to obtain the BaCl₂And (5) producing the product.

Background

In the production process of titanium dioxide by a chlorination method, the tail gas acid-washing waste acid of the chlorination process has 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.

Researchers develop a method for coating titanium dioxide by using hydrochloric acid as a byproduct of titanium chloride white, and the method is used for washing and recovering the tail gas of chlorination to contain TiOCl₂The crude hydrochloric acid as a coating agent is used for coating the titanium dioxide by adopting an inorganic and organic composite coating process, so that the hydrophilicity, chalking resistance, decoloring power and color retention of the titanium dioxide can be improved, but TiOCl in hydrochloric acid₂The hydrolysis is not complete in the process, the hydrochloric acid is not fully utilized, the process only uses the hydrochloric acid once, and the titanium chloride resource is not effectively utilized.

And the method is characterized in that acid tail gas generated in the chlorination method production process directly passes through a water washing tower, and the tail gas after water washing passes through an alkali washing tower and then is discharged after reaching the standard. Adding alkalinity to acidic waste water generated in the washing processSubstance, pH adjustment to TiOCl in solution₂In hydrolysis to form TiO₂Insoluble substances, filtering the solution, and recycling filter residues. The method enables TiOCl through simple neutralization₂Hydrolyzed to TiO₂Becomes solid waste, the solution obtains low-value chloride salt, and the resource utilization of the chloride salt with higher value is not realized.

In addition, carbon monoxide in the chlorination tail gas is used as a heat source, and the chlorination tail gas is pickled to obtain the product containing TiOCl₂The method for obtaining high-purity hydrogen chloride by desorption of by-product hydrochloric acid. Although the method can be used for desorbing and recovering the hydrochloric acid in the hydrochloric acid to obtain the hydrogen chloride with higher quality, the TiOCl in the hydrochloric acid can be recovered₂TiO separated from water in hydrochloric acid desorption process₂But becomes solid waste, and the resource utilization of the solid waste cannot be realized.

Other methods for preparing TiO by using waste gas of titanium dioxide produced by chlorination process₂And a HCl solution, introducing the chlorination waste gas generated in the production process of the chlorination-process titanium dioxide into an acid washing tower, and spraying 18-22% dilute hydrochloric acid to enable TiCl contained in the waste gas to be sprayed₄Absorption, TiCl in hydrochloric acid solution₄Hydrolysis reaction in water to generate TiOCl₂And HCl, passing through a two-stage membrane filtration system, and generating the chlorinated waste gas containing TiOCl₂Separating the hydrochloric acid solution to obtain hydrochloric acid solution and TiOCl₂TiO formed by hydrolysis₂. This method uses membrane filtration to separate TiOCl₂And HCl, which is less efficient and less economical.

Therefore, in order to efficiently utilize TiOCl contained in the production process of titanium dioxide by chlorination process₂The invention combines the production process of hydrochloric acid method barium chloride, and uses hydrochloric acid to carry out acidolysis on the witherite ore to ensure that metal elements such as Ba, Fe, Ca, Mg and the like in the witherite ore generate soluble chloride, and TiOCl in the hydrochloric acid₂Hydrolysis reaction occurs to precipitate hydrated TiO as the concentration of free hydrochloric acid decreases with the progress of acidolysis reaction₂The hydrochloric acid as the by-product of hydrolysis is used to supplement the hydrochloric acid consumed by acidolysis reaction of witherite. Separating siliceous acid insoluble substance in witherite ore and TiOCl in hydrochloric acid as by-product of titanium dioxide produced by chlorination process₂Ti produced by hydrolysisO₂Washing and drying to obtain a ceramic titanium dioxide finished product; adding Ba (OH) to the acid hydrolysis solution from which insoluble matter has been separated₂Neutralizing to remove impurity elements such as Fe, Ca, Mg, etc. in the form of hydroxide (pH value is controlled to be above 12.5), and adding controlled amount of H into the filtrate₂C₂O₄And activated carbon to further remove calcium impurities in the BaCl, and after twice impurity removal and purification₂Adjusting pH value of the solution to 7 with hydrochloric acid, performing flash evaporation concentration, and then performing freeze crystallization to separate hydrated BaCl₂.2H₂Washing and drying the O to obtain BaCl₂And (4) returning the crystallization filtrate to a primary neutralization process for recycling.

The main chemical reaction equation in the acidolysis process of witherite is as follows:

BaCO₃+2HCl=BaCl₂+ H₂O+CO₂

MgCO₃+2HCl=MgCl₂+H₂O+CO₂

CaCO₃+2HCl=CaCl₂+ H₂O+CO₂

FeO+2HCl= FeCl₂+2H₂O

Fe₂O₃+6HCl=2FeCl₃+3H₂O

TiOCl₂hydrolysis to produce TiO₂The chemical reaction equation of (a) is:

TiOCl₂+H₂O=TiO₂↓+2HCl。

disclosure of Invention

The invention aims to utilize a catalyst containing TiOCl₂The hydrochloric acid byproduct of titanium dioxide produced by the chlorination process is subjected to acidolysis reaction with the witherite ore, and the silicon dioxide acid insoluble substance and TiOCl in the hydrochloric acid byproduct are separated₂Hydrolysate TiO of₂Washing and drying twice to obtain a ceramic titanium dioxide product; the acidolysis is purified and the impurities are removed, and then the freezing crystallization, the washing and the drying are carried out to obtain the BaCl₂And (5) producing the product.

The invention relies on the acidification of witherite with hydrochloric acid to prepare BaCl₂Production method of the ore containing siliconAcid insoluble substance and TiOCl in hydrochloric acid byproduct of titanium dioxide produced by chlorination process₂TiO produced by hydrolysis₂As a ceramic titanium dioxide byproduct, the same BaCl is obtained₂And (5) producing the product. The method has the advantages that the titanium element in the hydrochloric acid byproduct of titanium dioxide produced by the chlorination process is utilized with high added value, the chlorine element is fully utilized, the defect of low utilization efficiency of the titanium element and the chlorine element in the existing method is overcome, and the high-efficiency resource utilization of the hydrochloric acid byproduct of titanium dioxide produced by the chlorination process is effectively realized.

The purpose of the invention is realized as follows:

measuring a certain amount of TiOCl₂Adding the byproduct hydrochloric acid of titanium white chloride into an acidolysis reaction kettle, simultaneously adding a certain amount of treated witherite slurry according to a certain acid-ore ratio, and closing a feed valve of the acidolysis reaction kettle. And (3) introducing steam into a jacket of the acidolysis reaction kettle for heating, keeping the acidolysis temperature at 85 +/-5 ℃, and starting stirring to ensure that the carbonate and the metal oxide in the witherite ore are fully contacted with hydrochloric acid for reaction. TiOCl in hydrochloric acid during acidolysis reaction₂Hydrolysis reaction occurs to precipitate hydrated TiO as the concentration of free hydrochloric acid decreases during the acidolysis reaction₂The hydrochloric acid as the by-product of hydrolysis is used to supplement the hydrochloric acid consumed by acidolysis reaction of witherite. After the reaction is finished, filtering the reactant, separating insoluble solids, washing and drying to obtain ceramic titanium dioxide which can be used in the ceramic industry; the solution containing metal chloride is sent to a primary neutralization reaction kettle, the temperature is kept to be not lower than 85 ℃, and Ba (OH) is added into the solution₂Controlling the pH value of the solution to be more than 12.5, filtering and separating insoluble solid phase after the reaction is finished, sending the filtrate to a secondary neutralization reaction kettle, and sequentially adding H₂C₂O₄Filtering, flash evaporating to concentrate, cooling to crystallize, washing and drying to obtain BaCl₂And (5) finishing.

The invention has the beneficial effects that: by using a catalyst containing TiOCl₂The chlorination titanium dioxide byproduct hydrochloric acid performs acidolysis reaction on witherite, and TiOCl is utilized₂The hydrochloric acid byproduct of the hydrolysis reaction is used for supplementing the hydrochloric acid consumed by the acidolysis reaction of the witherite, and the hydrochloric acid is generated by hydrolysisOf TiO 2₂Filtering and separating the heavy stone ore and acid insoluble substances containing silicon, and then treating to obtain ceramic titanium dioxide; removing impurities and purifying the acidolysis filtrate, crystallizing and separating out barium chloride, washing and drying to obtain BaCl₂And (5) finishing. The whole process realizes full resource utilization of the titanium element and the chlorine element in the raw materials, and greatly improves the economy of the process.

Drawings

FIG. 1 is a schematic view of a process flow of co-production of barium chloride and ceramic titanium white by hydrochloric acid as a byproduct of titanium dioxide 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.