CN-121986897-A - Preparation method and application of food-grade titanium dioxide with high dispersity

Abstract

The invention provides a preparation method of high-dispersity food-grade titanium dioxide and application thereof, and relates to the technical field of food additives, wherein the preparation method comprises the following steps of S1, mixing a titanium dioxide crude product with concentrated sulfuric acid and deionized water, pickling, stirring for 20-40 minutes, adding deionized water for washing, press-filtering until filtrate is neutral to obtain a filter cake, S2, filtering the filter cake through a sieving machine, sanding, adding deionized water for dilution and washing until the conductivity of slurry is stabilized below 400 mu S/cm, grading to obtain slurry containing fine particles, S3, press-filtering the slurry containing fine particles, adding deionized water into the obtained filter cake for redispersion, then spray-drying and crushing to obtain the food-grade titanium dioxide.

Inventors

• HAN XIAOYAN
• YANG CHEN

Assignees

• 淮安市鸿洋钛业有限公司

Dates

Publication Date

20260508

Application Date

20251218

Claims (10)

1. 1. The preparation method of the food-grade titanium dioxide with high dispersity is characterized by comprising the following steps of: S1, mixing a titanium dioxide crude product with concentrated sulfuric acid and deionized water, pickling, stirring for 20-40 minutes, adding deionized water for washing, and performing filter pressing until a filtrate is neutral to obtain a filter cake; S2, filtering the filter cake through a sieving machine, sanding, adding deionized water for dilution and washing until the conductivity of the slurry is stabilized below 400 mu S/cm, and grading to obtain slurry containing fine particles; And S3, press-filtering the slurry containing the fine particles, adding deionized water into the obtained filter cake to redisperse, then spray-drying and crushing to obtain the food-grade titanium dioxide.
2. 2. The method of claim 1, wherein the food grade titanium dioxide has a mercury content of 0.009 mg/kg, a lead content of 0.24 mg/kg, and an arsenic content of 0.91 mg/kg.
3. 3. The method of claim 1, wherein the food grade titanium dioxide has a particle size of 0.3 μm or less, a specific surface area of 12.3m2/g, and a pore structure of macropores greater than 50 nm.
4. 4. The method of claim 1, wherein the food grade titanium dioxide has a color value L of 99.3 and a color deviation a of 0.07.
5. 5. The preparation method of the powder collecting device according to claim 1, wherein in the step S3, compressed air is adopted to perform pulse back blowing ash removal in the powder collecting process, air pressure of an air supply system is controlled to be 90-110 Pa, back blowing pressure is controlled to be 0.3-0.4 MPa, and powder collecting equipment is a bag-type dust collector.
6. 6. The method according to claim 1, wherein the weight ratio of the crude titanium dioxide to the concentrated sulfuric acid to the deionized water in the step S1 is 5:1:10.
7. 7. The preparation method of claim 1, wherein the adding amount of the deionized water washed in the step S1 is 3-4 times of the weight of the crude titanium dioxide.
8. 8. The preparation method according to claim 1, wherein the sand grinding device in the step S2 is a sand grinder, and the sand grinding is performed for 2-3 times.
9. 9. The preparation method according to claim 1, wherein the classifying equipment in the step S2 is a horizontal spiral discharge decanter centrifuge, and the pulverizing equipment in the step S3 is a hammer pulverizer.
10. 10. Use of the food grade titanium dioxide obtained by the preparation method according to any one of claims 1 to 9 in food.

Description

Preparation method and application of food-grade titanium dioxide with high dispersity Technical Field The invention relates to the technical field of food additives, in particular to a preparation method and application of food-grade titanium dioxide. Background The food-grade titanium dioxide (known as titanium dioxide) is used as a white inorganic pigment, and is widely applied to industries such as food, medicine, cosmetics and the like, and is mainly used as a whitening agent and a coloring agent. However, during the application process, industrial grade titanium dioxide often contains various trace heavy metal harmful impurities (such as lead and arsenic), and cannot meet the relevant standards of food grade titanium dioxide. Moreover, the dispersibility and agglomeration of the titanium dioxide particles can directly affect the application effects, such as reduced product performance, reduced ‌ production efficiency, and high ‌ safety risk. Therefore, the preparation method and the application of the food-grade titanium dioxide capable of improving the dispersibility, reducing the agglomeration phenomenon and reducing the content of heavy metal harmful impurities are the problems to be solved at present. Disclosure of Invention The preparation method comprises the steps of S1, mixing a titanium dioxide crude product with concentrated sulfuric acid and deionized water, pickling, stirring for 20-40 minutes, adding deionized water for washing, press-filtering until filtrate is neutral to obtain a filter cake, S2, filtering the filter cake through a sieving machine, sanding, adding deionized water for dilution and washing until the conductivity of slurry is stabilized below 400 mu S/cm, grading to obtain slurry containing fine particles, S3, press-filtering the slurry containing the fine particles, adding deionized water into the obtained filter cake for redispersion, spray-drying and crushing to obtain the food-grade titanium dioxide. The invention aims at realizing the following technical scheme: in a first aspect, the invention provides a preparation method of high-dispersity food-grade titanium dioxide, which comprises the following steps: S1, mixing a titanium dioxide crude product with concentrated sulfuric acid and deionized water, pickling, stirring for 20-40 minutes, adding deionized water for washing, and performing filter pressing until a filtrate is neutral to obtain a filter cake; S2, filtering the filter cake through a sieving machine, sanding, adding deionized water for dilution and washing until the conductivity of the slurry is stabilized below 400 mu S/cm, and grading to obtain slurry containing fine particles; And S3, press-filtering the slurry containing the fine particles, adding deionized water into the obtained filter cake to redisperse, then spray-drying and crushing to obtain the food-grade titanium dioxide. In some embodiments of the invention, the food grade titanium dioxide has a mercury content of 0.009 mg/kg, a lead content of 0.24 mg/kg, and an arsenic content of 0.91 mg/kg. In some embodiments of the invention, the food grade titanium dioxide has a particle size of 0.3 μm or less, a specific surface area of 12.3m2/g, and a pore structure of macropores greater than 50 nm. In some embodiments of the present invention, the food grade titanium dioxide has a color value L of 99.3 and a color deviation a of 0.07. In some specific embodiments of the invention, in the step S3, compressed air is adopted to perform pulse back-blowing ash removal in the powder collecting process, the air pressure of an air supply system is controlled to be 90-110 Pa, the back-blowing pressure is controlled to be 0.3-0.4 MPa, and the powder collecting equipment is a bag-type dust collector. In some embodiments of the present invention, the weight ratio of the crude titanium dioxide to concentrated sulfuric acid to deionized water in step S1 is 5:1:10. In some embodiments of the present invention, the deionized water added in the step S1 is 3 to 4 times the weight of the crude titanium dioxide. In some embodiments of the present invention, the sand grinding device in step S2 is a sand grinder, and the sand grinding is performed for 2-3 times. In some embodiments of the present invention, the classifying device in step S2 is a horizontal spiral discharge decanter centrifuge, and the pulverizing device in step S3 is a hammer pulverizer. In a second aspect, the invention provides the use of the food grade titanium dioxide obtained by the preparation method of the first aspect in food. The beneficial effects obtained by the invention are as follows: The food-grade titanium dioxide obtained by the preparation method provided by the invention has excellent dispersibility and long-term suspension stability, extremely high whiteness and extremely low color cast, the content of harmful heavy metals is reduced to extremely low level, the grain diameter is controlled below 0.3 mu m by fine processing steps of san