CN115448358B - Method for removing iron in low-concentration industrial titanium liquid hydrolysis process - Google Patents
Method for removing iron in low-concentration industrial titanium liquid hydrolysis process Download PDFInfo
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Abstract
The invention provides a method for removing iron in a low-concentration industrial titanium liquid hydrolysis process, and belongs to the technical field of titanium dioxide manufacturing. The method may comprise the steps of: after the low-concentration industrial titanium liquid is hydrolyzed and is subjected to ash formation point and curing for 20-40 minutes, stirring is started, 40-60% glycerol aqueous solution is added into a hydrolysis slurry system, and the addition amount is controlled to be 0.05-0.10L/m 3 Stirring and uniformly mixing a hydrolysis slurry system (based on the volume of the titanium liquid hydrolysis slurry); adding carboxymethyl cellulose into the hydrolysis slurry system, wherein the addition amount is controlled to be 0.70-1.5 g/m 3 And after the addition, stirring and uniformly mixing the hydrolysis slurry system, namely removing ferrous impurities in the hydrolysis process of the low-concentration industrial titanium liquid. The method for removing iron in the hydrolysis process of the low-concentration industrial titanium liquid has the advantages of high ferrous impurity ion removal rate, simple process and low cost, and can be widely popularized and used.
Description
Technical Field
The invention relates to a method for removing iron in a low-concentration industrial titanium liquid hydrolysis process, and belongs to the technical field of titanium dioxide manufacturing.
Background
Along with the continuous progress and development of the domestic sulfuric acid process titanium white technology, the production scale is continuously enlarged, and the requirements on the subdivision and quality of titanium white products are higher and higher. At present, the production of titanium white products in China mainly adopts a sulfuric acid process, and the intermediate product, namely the meta-titanic acid, is prepared by acidolysis, leaching and concentration of titanium concentrate or titanium slag and then hydrolysis. Acidolysis leached dilute titanium solution TiO 2 The mass concentration is 140-190 g/L, which contains a large amount of SO 4 2- Impurity ions such as Fe, al, V, cr, mn affect the normal hydrolysis of the titanium liquid and the composition structure of the meta-titanic acid, and are carried out along with the precipitation of the hydrolyzed meta-titanic acid. The hydrolytic meta-titanic acid is an amorphous titanium dioxide hydrate, has obvious colloid property, contains a small amount of titanium dioxide crystal structure ions of a anatase phase, and is adsorbed with a large amount of water, sulfate radical and Fe 2+ And the like. When impurity ions such as ferrous iron and the like are mixed into the meta-titanic acid, if the content of the impurity ions is too high, the crystal form transformation and the crystal grain growth of the meta-titanic acid in the calcining process are influenced, lattice defects are generated, the impurity content of titanium dioxide of a product is increased, the color of the titanium dioxide of the product is influenced, meanwhile, the composition structure and the application performance of the product are adversely affected, and the added value of the product is reduced. Therefore, controlling the ferrous impurity content of the hydrolyzed meta-titanic acid is a key problem of quality stabilization, quality improvement and synergy of the titanium dioxide product.
How to regulate and control hydrolysis process conditions to control the composition and structure of the precipitated and hydrolyzed metatitanic acid, and to reduce the ferrous ion content in the metatitanic acid and purify the metatitanic acid by changing the surface property and aggregation structure of the metatitanic acid is an important problem to be considered in the titanium white industry, and has important economic and social benefits.
Disclosure of Invention
The invention solves the technical problem of providing a method for removing iron in the hydrolysis process of low-concentration industrial titanium liquid.
The method for removing iron in the hydrolysis process of the low-concentration industrial titanium liquid comprises the following steps of:
a. after the low-concentration industrial titanium liquid is hydrolyzed and is subjected to ash formation point, curing is carried out for 20-40 minutes, and after the process is finished, stirring is started, 40% -60% by mass of glycerol aqueous solution is added into a hydrolysis slurry system, and the adding amount of the glycerol aqueous solution is 0.05-0.10L/m based on the volume of the titanium liquid hydrolysis slurry 3 Stirring and uniformly mixing a hydrolysis slurry system;
b. adding carboxymethyl cellulose into the hydrolysis slurry system in the step a, wherein the adding amount of the carboxymethyl cellulose is 0.70-1.5 g/m based on the volume of the titanium liquid hydrolysis slurry 3 After the addition, the mixture is stirred and evenly mixed to hydrolyze the slurry system.
Wherein, the titanium content in the low-concentration industrial titanium liquid is TiO 2 The mass concentration is 140-190 g/L.
Preferably, the low-concentration industrial titanium liquid in the step a is hydrolyzed to form an ash point, and the curing time is 30min.
Preferably, the adding amount of the glycerol aqueous solution in the step a is controlled to be 0.08-0.10L/m 3 。
In the step a of the method, the main function of the glycerol is that the glycerol can be combined with the hydrolytic-precipitated metatitanic acid through the hydroxy complexation, so that the surface potential of the metatitanic acid is reduced, the hydrophilic property of the metatitanic acid surface is weakened, the adsorption capacity of impurity ions such as ferrous ions on the metatitanic acid surface is reduced, the adsorption quantity of the impurity ions such as ferrous ions on the metatitanic acid surface is reduced, the iron removal function is realized, and the purity of the metatitanic acid is improved. In step a of the above process, if other polyols are added, such as: ethylene glycol is difficult to achieve the iron removal effect.
Preferably, the addition amount of the carboxymethyl cellulose in the step b is controlled to be 0.9-1.2 g/m 3 . In the step b, the added carboxymethyl cellulose is mainly used as a flocculating agent to gather the metatitanic acid particles in the hydrolyzed slurry, so that the metatitanic acid particles separated out by hydrolysis can be flocculated and grown greatly, the granularity of the gathered particles of the metatitanic acid is increased, the specific surface area of the metatitanic acid is reduced, the adsorption quantity of impurity particles is reduced, the purity of the metatitanic acid is improved, the washing efficiency of solid-liquid separation after the hydrolysis is finished is improved, and the iron removal effect is improved.
The invention has the beneficial effects that:
1. according to the method for removing iron in the hydrolysis process of the low-concentration industrial titanium liquid, disclosed by the invention, the hydrophilic property of the surface of the meta-titanic acid is changed by adopting an organic reagent and the meta-titanic acid through hydroxyl complexation so as to reduce the adsorption of impurity ions, and the flocculating agent carboxymethyl cellulose is adopted to gather meta-titanic acid particles so as to reduce the specific surface area of the meta-titanic acid and the adsorption of the impurity ions, so that the adsorption of the meta-titanic acid to the impurity ions such as ferrous ions is reduced, and the iron removal effect is realized. The iron removing effect in the low-concentration titanium liquid hydrolysis process is obvious, and the ferrous impurity ion removing rate is high.
2. The method for removing iron in the hydrolysis process of the low-concentration industrial titanium liquid has the characteristics of simple process, low cost and remarkable iron removing effect.
Detailed Description
Embodiments of the present invention will be described in detail below with reference to specific examples, but it will be understood by those skilled in the art that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention. The examples were conducted under conventional conditions, except that the specific conditions were not specified.
Example 1
After the low-concentration industrial titanium liquid is hydrolyzed and becomes ash point and curing is finished for 30 minutes, stirring is started, and the concentration of the slurry (TiO 2 155g/L by mass) of a hydrolysis system, and adding an aqueous solution of glycerol with a mass concentration of 55% by mass to the hydrolysis system in an amount of 0.90L/m 3 Stirring and uniformly mixing a hydrolysis slurry system (based on the volume of the titanium liquid hydrolysis slurry); adding 1.2g/m by volume of the hydrolysis slurry 3 The carboxymethyl cellulose of (2) is stirred to be uniformly mixed. After the hydrolysis is finished, the iron content in the meta-titanic acid is measured to be 0.14%, and the iron content (0.25%) of the meta-titanic acid which is not treated is 0.11% lower, and the iron removal rate is 44%.
Example 2
After the low-concentration industrial titanium liquid is hydrolyzed and becomes ash point and curing is finished for 30 minutes, stirring is started, and the concentration of the slurry (TiO 2 140g/L by mass) of a 43% by mass aqueous glycerol solution was added to the hydrolysis system in an amount of 0.75L/m 3 Stirring and uniformly mixing a hydrolysis slurry system (based on the volume of the titanium liquid hydrolysis slurry); adding 0.90g/m of the hydrolysis slurry according to the volume of the hydrolysis slurry 3 The carboxymethyl cellulose of (2) is stirred to be uniformly mixed. After the hydrolysis is finished, the iron content in the meta-titanic acid is measured to be 0.12%, and the iron content (0.22%) of the meta-titanic acid which is not treated is 0.10% lower, and the iron removal rate is 45%.
Example 3
After the low-concentration industrial titanium liquid is hydrolyzed and becomes ash point and curing is finished for 30 minutes, stirring is started, and the concentration of the slurry (TiO 2 148g/L by mass) of a hydrolysis system, adding a water solution of glycerol with a mass concentration of 51% to the hydrolysis system in an amount of 0.86L/m 3 Stirring and uniformly mixing a hydrolysis slurry system (based on the volume of the titanium liquid hydrolysis slurry); adding 1.1g/m of the hydrolysis slurry by volume 3 The carboxymethyl cellulose of (2) is stirred to be uniformly mixed. After the hydrolysis is finished, the iron content in the meta-titanic acid is measured to be 0.13%, and the iron content (0.23%) of the meta-titanic acid which is not treated is 0.10% lower, and the iron removal rate is 43%.
Comparative example 1
After the low-concentration industrial titanium liquid is hydrolyzed and becomes ash point and curing is finished for 30 minutes, stirring is started, and the concentration of the slurry (TiO 2 155g/L by mass) of a hydrolysis system, and adding an aqueous solution of glycerol with a mass concentration of 55% by mass to the hydrolysis system in an amount of 0.90L/m 3 (based on the volume of the titanium liquid hydrolysis slurry), the hydrolysis slurry system is stirred and mixed. After the hydrolysis is finished, the iron content in the meta-titanic acid is measured to be 0.19%, and the iron content (0.25%) of the meta-titanic acid which is not treated is 0.06% lower, and the iron removal rate is 24%.
Comparative example 2
After the low-concentration industrial titanium liquid is hydrolyzed and becomes ash point and curing is finished for 30 minutes, stirring is started, and the concentration of the slurry (TiO 2 Mass) of 155g/L of a hydrolysis system was added to 1.2g/m of the reaction mixture 3 The carboxymethyl cellulose of (2) is stirred to be uniformly mixed. After the hydrolysis is finished, the iron content in the meta-titanic acid is measured to be 0.20%, and the iron content (0.25%) of the meta-titanic acid which is not treated is 0.05% lower, and the iron removal rate is 20%.
Comparative example 3
After the low-concentration industrial titanium liquid is hydrolyzed and becomes ash point and curing is finished for 30 minutes, stirring is started, and the concentration of the slurry (TiO 2 Mass) 140g/L of 43% aqueous glycol solution was added to the hydrolysis system in an amount of 0.75L/m 3 Stirring and uniformly mixing a hydrolysis slurry system (based on the volume of the titanium liquid hydrolysis slurry); adding 0.90g/m of the hydrolysis slurry according to the volume of the hydrolysis slurry 3 The carboxymethyl cellulose of (2) is stirred to be uniformly mixed. After the hydrolysis is finished, the iron content in the meta-titanic acid is measured to be 0.17%, and the iron content (0.22%) of the meta-titanic acid which is not treated is 0.05% lower, and the iron removal rate is 23%.
Comparative example 4
After the low-concentration industrial titanium liquid is hydrolyzed and becomes ash point and curing is finished for 30 minutes, stirring is started, and the concentration of the slurry (TiO 2 140g/L by mass) of a 43% by mass aqueous glycerol solution was added to the hydrolysis system in an amount of 0.75L/m 3 Stirring and uniformly mixing a hydrolysis slurry system (based on the volume of the titanium liquid hydrolysis slurry); adding 0.90g/m of the hydrolysis slurry according to the volume of the hydrolysis slurry 3 Polyacrylamide of (a)Stirring and evenly mixing the system. After the hydrolysis is finished, the iron content in the meta-titanic acid is measured to be 0.16%, and the iron content (0.22%) of the meta-titanic acid which is not treated is 0.06% lower, and the iron removal rate is 26%.
The present embodiment is merely illustrative of the invention and not intended to be limiting, and those skilled in the art will make modifications or improvements on the basis of the present invention after reading the description of the invention, but are protected by the patent laws within the scope of the claims of the present invention.
Claims (5)
1. The method for removing iron in the hydrolysis process of the low-concentration industrial titanium liquid is characterized by comprising the following steps of:
a. after the low-concentration industrial titanium liquid is hydrolyzed and is subjected to ash formation point, curing is carried out for 20-40 minutes, and after the process is finished, stirring is started, 40% -60% by mass of glycerol aqueous solution is added into a hydrolysis slurry system, and the adding amount of the glycerol aqueous solution is 0.05-0.10L/m based on the volume of the titanium liquid hydrolysis slurry 3 Stirring and uniformly mixing a hydrolysis slurry system;
b. adding carboxymethyl cellulose into the hydrolysis slurry system in the step a, wherein the adding amount of the carboxymethyl cellulose is 0.70-1.5 g/m based on the volume of the titanium liquid hydrolysis slurry 3 After the addition, the mixture is stirred and evenly mixed to hydrolyze the slurry system.
2. The method for removing iron in the hydrolysis process of low-concentration industrial titanium liquid according to claim 1, wherein the method comprises the following steps: the titanium content in the low-concentration industrial titanium liquid is TiO 2 The mass concentration is 140-190 g/L.
3. The method for removing iron in the hydrolysis process of low-concentration industrial titanium liquid according to claim 1, wherein the method comprises the following steps: and c, hydrolyzing the low-concentration industrial titanium liquid in the step a, and curing for 30min after ash formation.
4. The method for removing iron in the hydrolysis process of low-concentration industrial titanium liquid according to claim 1, wherein the method comprises the following steps: the adding amount of the glycerol aqueous solution in the step a is 0.08-0.10L/m 3 。
5. The method for removing iron in the hydrolysis process of low-concentration industrial titanium liquid according to claim 1, wherein the method comprises the following steps: the addition amount of the carboxymethyl cellulose in the step b is 0.9 to 1.2g/m 3 。
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