Method for preparing mixed-crystal double-effect seed crystal for production of titanium dioxide by sulfuric acid method

A dual-effect seed crystal, titanium dioxide technology, applied in chemical instruments and methods, titanium dioxide, titanium compounds, etc., can solve the problems of high cost, no industrialization, unstable quality, etc., to save steam and natural gas, and reduce market dependence. performance and cost savings

Active Publication Date: 2016-11-09
SICHUAN LOMON TITANIUM IND CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The double-effect seed crystal process has been reported in the literature. The domestic patent CN102390865A uses the intermediate metatitanic acid produced by titanium dioxide as a raw material, and is dissolved in sulfuric acid, precipitated in sodium carbonate, washed twice, dissolved in acid, and cooled to obtain nano-sized colloidal bis 2% seed crystals are added for hydrolysis, calcined seeds are no longer added for calcination, and excellent quality rutile titanium dioxide is obtained. This process has high quality and activity of seed crystals, but it consumes 4 to 5 times of sulfuric acid and a large amount of sodium carbonate, which cannot be recovered. , the cost is high, the seed crystal preparation process is long, and the quality is unstable, but there is no industrialization promotion
[0007] There is also a domestic patent CN1415548A which introduces a kind of SnO 2 +TiO 2 Double effect seed crystal, containing SnO in the seed crystal 2 , cannot be put into practical application due to cost and technical problems
Patent CN101565201A has reported that the content of rutile obtained by the calcined seed crystal process is 90-98% suspended liquid crystal seeds, which is called a double-effect crystal seed, but there is no specific description of the hydrolysis and calcination activity experimental data, only the crystal is given. The analysis results of the rutile content of the seed, whether it is a real double-effect seed crystal, needs to be verified

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] Bleach metatitanic acid to Fe≤50ppm, beating, the beating concentration is 10%, add it to a four-neck flask, add sodium hydroxide with a purity of more than 94% according to the mass ratio of 5:1, heat up to boiling, keep boiling for 3 hours, and cool To below 50°C, filter, wash with desalted water at room temperature until the alkali content in the filtrate is ≤2g / L; beat the filter cake to a concentration of 50g / L, add 0.5 times HCl, heat up to 85°C, keep it warm for 60min, add the same volume of normal temperature desalination The water is rapidly cooled to below 50°C to obtain nano-scale seeds.

Embodiment 2

[0028] Bleach metatitanic acid to Fe≤50ppm, beating, beating concentration is 12%, add to four-necked flask, add potassium hydroxide with purity above 94% according to the mass ratio of 4:1, heat up to boiling, keep boiling for 3h, cool To below 50°C, filter, wash with desalted water at room temperature until the alkali content in the filtrate is ≤2g / L; beat the filter cake to a concentration of 100g / L, add 0.8 times HCl, heat up to 90°C, keep warm for 30min, add the same volume of normal temperature desalination The water is rapidly cooled to below 50°C to obtain nano-scale seeds.

Embodiment 3

[0030] Bleach metatitanic acid to Fe≤50ppm, beating, the beating concentration is 23%, add it to a four-neck flask, add sodium carbonate with a purity of more than 94% according to the mass ratio of 3:1, heat up to boiling, keep boiling for 3 hours, and cool to Below 50°C, filter, wash with desalted water at room temperature until the alkali content in the filtrate is ≤2g / L; beat the filter cake to a concentration of 200g / L, add 1.0 times HCl, heat up to 95°C, keep warm for 10min, add the same volume of desalted water at room temperature Rapid cooling to below 50°C yields nanoscale seeds.

[0031] Numbering

[0032] It can be seen from the analysis results in the above table that the obtained seed crystals are mixed crystal nanocrystals with a specific surface area of ​​175m 2 / g or more, particle size below 5nm.

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Abstract

The invention relates to a method for preparing mixed-crystal double-effect seed crystal for production of titanium dioxide by a sulfuric acid method. The method comprises the steps of alkali dissolution, washing, acid dissolution, cooling and the like, wherein alkali dissolution is carried out in an alkali-titanium ratio of 3:1-5:1; in the acid dissolution reaction, 0.5-1.0 time of hydrochloric acid is added to dissolve for 10-60 minutes at 85-95 DEG C, and extremely freezing is carried out until the temperature is below 50 DEG C to obtain the nano-grade mixed-crystal double-effect seed crystal. According to the method, the seed crystal is added during hydrolyzing, no calcining seed crystal is required during calcining, the process for preparing a calcining seed crystal is eliminated, preparation of hydrolyzing and calcining seed crystal can be completed in one time, complicated process of respectively preparing hydrolyzing seed crystal and calcining seed crystal can be avoided, cost can be saved and product quality can be improved.

Description

technical field [0001] The invention relates to a method for preparing mixed-crystal double-effect seed crystals for the production of sulfuric acid-process titanium dioxide, in particular to a preparation method for nano-scale mixed-crystal double-effect seed crystals. Background technique [0002] In the production process of sulfuric acid titanium dioxide, two types of seeds are involved, hydrolyzed seeds and calcined seeds, which play different roles due to their differences in properties and characteristics, so their preparation processes are also very different. [0003] Generally, the main function of the hydrolysis seed is to hydrolyze titanium sulfate (oxygen) into the crystal nucleus of metatitanic acid, promote rapid hydrolysis, increase the hydrolysis yield, and improve the performance of the pigment, so the seed crystal particles are small and the degree of crystallization is low. There are two kinds of shapes introduced in the literature, one is needle-shaped, ...

Claims

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Application Information

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IPC IPC(8): C01G23/053
CPCC01G23/0534
Inventor 林发蓉周晓葵姚恒平朱全芳周春勇熊怀忠沈亮
Owner SICHUAN LOMON TITANIUM IND CO LTD
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