WO2013020430A1

WO2013020430A1 - Method for preparing high dispersion rutile product

Info

Publication number: WO2013020430A1
Application number: PCT/CN2012/078205
Authority: WO
Inventors: 代堂军; 蔡平雄; 常键; 邓伯松; 朱全芳
Original assignee: 四川龙蟒钛业股份有限公司
Priority date: 2011-08-11
Filing date: 2012-07-05
Publication date: 2013-02-14
Also published as: CN102391689B; CN102391689A

Abstract

Disclosed is a method for preparing a high dispersion rutile product manufactured by a sulfuric acid process, the method comprising the steps of: acidolysis reaction, hydrolysis to generate metatitanic acid, salt treatment, calcination, wet grinding, then sand milling, coating and air-blowing milling, so as to obtain finished titanium dioxide; washing the rutile titanium dioxide crude product resulting from calcination with water to reduce the content of water soluble salts therein, and then adding a dispersing agent to the washed rutile titanium dioxide and wet grinding. The rutile product prepared by the method has an alkyd resin system with a dispersity of 20° and a gloss of up to more than 120. The method uses a reduced amount of the dispersing agent in the wet grinding, saving costs, and improves the dispersion property of the product.

Description

Description Method for preparing highly dispersed rutile product

The invention relates to a preparation method of rutile type titanium dioxide, in particular to a preparation method of rutile with specific high dispersibility.

Background technique

Titanium dioxide is one of the most important inorganic pigments and chemical raw materials. Pigment grade titanium dioxide is mainly used in coatings, paper, plastics, rubber, latex paints, printing inks, chemical fiber and other industries. Non-pigment grade titanium dioxide is mainly used in enamel, capacitors and welding electrodes.

The production method of titanium dioxide is generally classified into a sulfuric acid method and a chlorine method. The sulfuric acid method is a common traditional production method, and the steps generally include: the acid hydrolysis reaction of titanium iron powder with concentrated sulfuric acid to produce titanium sulfate sulfate, sedimentation, crystallization, hydrolysis to form meta-antimonic acid, and the addition of metatitanic acid Bleaching, second washing, salt treatment, calcination to obtain crude rutile titanium dioxide, wet titanium dioxide added to the dispersing agent, wet grinding to obtain rutile titanium dioxide slurry, sanding, and then coating the film and gas powder to obtain the product.

In the above-mentioned sulfuric acid process titanium dioxide production process, in order to make the product have better pigment properties and application properties, a plurality of metal ions are generally added to the metatitanic acid as a salt treatment agent before calcination, and these metal ions include potassium and sodium. Magnesium, zinc, zirconium, aluminum, lithium and phosphorus. The purpose of adding potassium and phosphorus during the calcination of metatitanic acid is to obtain a softer crude rutile titanium dioxide for subsequent grinding; the addition of aluminum is to improve the weatherability and pigment properties of the pigment; the addition of zinc, lithium and magnesium is mainly In order to reduce the temperature required for the conversion of anatase to rutile, the calcination strength is lowered. Usually, a certain amount of calcined seed crystals are added to the metatitanic acid to be calcined to lower the calcination temperature to obtain pigment particles having a suitable particle diameter.

At the end of the calcination, the salt treatment agent is converted into a sulfate or an oxide, and the content of the water-soluble salt is generally

The S0 ₃ meter is based on 0.30-1.00% of the total rutile type titanium dioxide, and the dispersion effect of the cerium oxide slurry cannot be improved even under the action of a large amount of dispersing agent, and even the grinding cannot be continued, so that the water dispersibility of the pigment particles is lowered, and further Affects the quality of the grinding and the dispersion of the rutile finished product.

The dispersibility of the rutile finished product is the most important quality index of titanium dioxide. Good dispersibility is of great significance for improving the pigment performance of titanium dioxide and reducing the grinding time. In order to improve the dispersibility of titanium dioxide, the methods currently used are to reduce the calcination strength of metatitanic acid, to extend the sanding time, and to make a reasonable replacement page (Article 26) Membrane treatment and improvement of gas powder strength, etc. However, these methods have great limitations. For example, reducing the calcination strength of metatitanic acid will reduce the weather resistance of the product; prolonging the sanding time will pollute the raw materials and reduce the brightness of the product; the effect of the coating on the dispersibility of the finished titanium dioxide is not obvious; The method of improving the dispersibility of the finished product has high energy consumption and is not cost-effective. There has been no research to improve the dispersibility of rutile products by improving the pre-crushing effect of titanium dioxide.

Summary of the invention

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for significantly increasing the rutile dispersibility in view of the above problems.

The technical scheme adopted by the present invention is as follows: a preparation method of a highly dispersed rutile product, which is produced by a sulfuric acid method, and includes the following steps in sequence: an acid hydrolysis reaction of titanium concentrate with concentrated sulfuric acid to produce titanium sulfate, and then hydrolyzed to form a partial Titanic acid, salt treatment, calcination to obtain crude rutile titanium dioxide, titanium dioxide crude added to the dispersant, wet grinding to obtain rutile titanium dioxide slurry, sand, coated and gas powder to obtain titanium dioxide finished product, obtained by calcination The crude rutile titanium dioxide is washed with water to reduce the content of the water-soluble salt therein, and then the water-washed rutile-type titanium dioxide is further added to a dispersing agent for wet grinding.

Preferably, the crude rutile-type titanium dioxide obtained by calcination is washed with water to reduce the content of the water-soluble salt therein to 0.25% or less based on the mass of the washed rutile-type titanium dioxide based on S0 ₃ . The experimental results show that the lower the water-soluble salt content, the better the dispersibility of the rutile product obtained under the same conditions.

Preferably, the dispersing agent is at least one of sodium hydroxide, sodium silicate, sodium hexametaphosphate, sodium polycarboxylate, monoethanolamine, and monoisopropanolamine.

Preferably, the dispersant is added in an amount of from 0.05 to 0.60% based on the mass of the total titanium dioxide in the rutile-type titanium dioxide slurry.

Preferably, the water washing method is a method in which a crude rutile-type titanium dioxide obtained by calcination is mixed with water, stirred, allowed to stand and decanted, and the above operation is repeated as necessary.

The inventors of the present application have found through a large number of studies that if the crude rutile titanium dioxide is not subjected to a water washing process and the amount of the dispersant is 0.05-3.00% based on the mass of the total titanium dioxide in the rutile-type titanium dioxide slurry, the wet milling feed concentration is controlled to the highest. in the titanium dioxide meter 400-700g / _L; when the rutile titania after washing process, the water-soluble salts of titanium dioxide in the S0 ₃ content of the total count of less than 0.25% titanium dioxide based on the amount of dispersant may be only 0.20% The wet mill feed concentration is between 800 and 1400 g/L in terms of titanium dioxide. The crude rutile is washed away with most of the coarse salt to increase the wet grinding concentration.

Replacement page (Article 26) Pre-crushing effect of bismuth titanium dioxide.

Washed rutile crude product may take a wide variety of devices, the easiest way is to mix titanium dioxide and water, stirring, settling and decanting operation is repeated until the number of the water-soluble salt content of titanium dioxide so ₃ based on the total titanium oxide is less than 0.25% . Then adding 0.05-0.60% dispersant and water, adding the material to the ball mill for wet grinding, and grinding through the set time, 99.9% of the titanium dioxide in the slurry passes through the 325 mesh standard sieve, that is, the pre-crushing effect is very good, and this When the concentration of titanium dioxide in the wet abrasive slurry can reach 1400 g/L, the wet abrasive slurry is sanded under the same conditions, and the rutile product obtained after the coating is processed for treatment has higher dispersibility.

In summary, the beneficial effects of the present invention are as follows: the rutile product prepared by the method of the invention has an alkyd resin system having a 20 degree gloss of 120 degrees or more, and the crude rutile product is not washed with water, and then the same post-treatment method is adopted. The prepared rutile product has an alkyd resin system with a dispersibility of 20 degrees gloss of up to 100, and the amount of dispersant in the wet grinding process is greatly reduced, which not only saves cost but also greatly improves product dispersion performance.

detailed description

The invention will now be described in detail.

In order to make the objects, technical solutions and advantages of the present invention more comprehensible, the present invention will be further described in detail below with reference to the embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Comparative Example 1: Preparation of rutile by the existing common method

The bleached qualified metatitanic acid is phosphoric acid (0.20% by mass of phosphorus pentoxide), potassium sulfate (0.30% by mass of potassium oxide) and aluminum sulfate (0.33 by mass of aluminum oxide) %) After calcination at 950 ° C to rutile content greater than 98.0%, take the calcined product, add 0.20% of the total titanium dioxide mass to the dispersant sodium silicate solution, add water to beat the titanium dioxide containing 600 g / L, and grind for 1 hour with a ball mill. The obtained slurry was sanded, and the coated film was processed to obtain the rutile finished product A. The 20 degree gloss data of A is shown in Table 1.

Comparative example 2

The calcined product of Example 1 was added to a dispersant sodium silicate solution at a mass of 0.20% of total titanium dioxide, and water was beaten to a titanium dioxide content of 1000 g/L, and the obtained slurry was subjected to a ball mill grinding, sanding, and coating in Example 1. After the film is processed, the rutile finished product B is obtained, and the 20-degree gloss data of B is shown in Table 1.

Replacement page (Article 26) Example 1

The calcined product of Example 1 was taken, and the salt content was reduced to 0.50% by a water washing operation, and the dispersant sodium silicate solution was added to 0.20% of the total titanium dioxide mass, and water was beaten to a titanium oxide content of 1000 g/L, and the obtained slurry was implemented. In Example 1, the ball mill was used for grinding, sanding, and coating to obtain the rutile finished product C, and the 20 degree gloss data of C is shown in Table 1.

Example 2

The calcined product of Example 1 was taken, and the salt content was reduced to 0.40% by a water washing operation, and the dispersant sodium silicate solution was added to 0.20% of the total titanium dioxide mass, and water was beaten to a titanium oxide content of 1000 g/L, and the obtained slurry was subjected to implementation. In Example 1, the ball mill was used for grinding, sanding, and the coating was awaiting treatment to obtain the rutile finished product D. The 20 degree gloss data of D is shown in Table 1.

Example 3

The calcined product of Example 1 was taken, and the salt content was reduced to 0.30% by a water washing operation, and the dispersant sodium silicate solution was added at 0.20% of the total titanium dioxide mass, and water was beaten to a titanium oxide content of 1000 g/L, and the obtained slurry was subjected to a slurry. In Example 1, the ball mill was used for grinding, sanding, and the coating was awaiting treatment to obtain the rutile finished product E. The 20 degree gloss data of E is shown in Table 1.

Example 4

The calcined product of Example 1 was taken, and the salt content was reduced to 0.25% by a water washing operation, and the dispersant sodium silicate solution was added at 0.20% of the total titanium dioxide mass, and water was beaten to a titanium oxide content of 1000 g/L, and the obtained slurry was subjected to a slurry. In Example 1, the ball mill was used for grinding, sanding, and the coating was awaiting treatment to obtain the rutile finished product F. The 20 degree gloss data of F is shown in Table 1.

Example 5

The calcined product of Example 1 was taken, and the salt content was reduced to 0.20% by a water washing operation, and the dispersant sodium silicate solution was added to 0.20% of the total titanium dioxide mass, and the slurry was added with water to a titanium oxide content of 1000 g/L, and the obtained slurry was implemented. In Example 1, the ball mill was used for grinding, sanding, and the coating was awaiting treatment to obtain the rutile finished product G. The 20 degree gloss data of G is shown in Table 1.

Example 6

The calcined product of Example 1 was taken, and the salt content was reduced to 0.10% by a water washing operation, and the dispersant sodium silicate solution was added to the total titanium dioxide mass 0.05%, and the water was beaten to a titanium dioxide content of 1000 g/L, and the obtained slurry was carried out. In Example 1, the ball mill was used for grinding, sanding, and the coating was awaiting treatment to obtain rutile.

Replacement page (Article 26) The 20 degree gloss data of the products H and H are shown in Table 1.

Example 7

The calcined product of Example 1 was taken, and the salt content was reduced to 0.10% by a water washing operation, and the dispersant sodium silicate solution was added to 0.20% of the total titanium dioxide mass, and water was beaten to a titanium dioxide content of 1000 g/L, and the obtained slurry was subjected to a slurry. In Example 1, the 20-degree gloss data of the rutile finished product I, I obtained by grinding with a ball mill, sanding, and coating waiting for treatment is shown in Table 1.

Table 1. Dispersion of rutile finished product AH

It can be seen from Table 1 that under the same conditions, the dispersibility of the washed rutile finished product is better than that of the non-washed rutile finished product. Although increasing the wet grinding concentration can improve the dispersibility, the crude rutile product is not washed with water. The dispersion of titanium dioxide finished products is still very poor (Comparative Examples 1 and 2); Moreover, the smaller the rutile crude salt content after washing under the same conditions, the better the dispersibility; at the same time, compared with the water-washed, washed After that, the amount of dispersing agent used in rutile crude wet grinding is greatly reduced, and the obtained rutile finished product has higher dispersibility, and the dispersing agent is saved, and a higher dispersible rutile product can be obtained.

Replacement page (Article 26)

Claims

Rights request:

1. A method for preparing a highly dispersed rutile product, which is produced by a sulfuric acid method, and comprises the following steps: an acid hydrolysis reaction of titanium concentrate with concentrated sulfuric acid to produce titanium sulfate, followed by hydrolysis to form metatitanic acid, and then salt treatment, Calcined to obtain crude rutile titanium dioxide, crude titanium dioxide added to the dispersant, wet grinding to obtain rutile titanium dioxide slurry, sand, coated and gas powder to obtain titanium dioxide finished product, characterized by: rutile type dioxide obtained by calcination The crude product is washed with water, and then the washed rutile titanium dioxide is further added to a dispersing agent for wet grinding.

2. The method for preparing a highly dispersed rutile product according to claim 1, wherein: the crude rutile-type titanium dioxide obtained by calcination is washed with water to reduce the content of the water-soluble salt therein to be based on the washed rutile-type titanium dioxide by S0 ₃ . 25%以下以下。 The crude product quality of 0.25% and below.

The method for preparing a highly dispersed rutile product according to claim 1 or 2, wherein the dispersing agent is sodium hydroxide, sodium silicate, sodium hexametaphosphate, sodium polycarboxylate, monoethanolamine, single At least one of isopropanolamine.

The method for preparing a highly dispersed rutile product according to claim 1 or 2, wherein: the amount of the dispersant added is based on the mass of total titanium dioxide in the rutile-type titanium dioxide slurry.

0. 05-0. 60%

The method for preparing a highly dispersed rutile product according to claim 2, wherein the water washing method comprises mixing the crude rutile-type titanium dioxide obtained by calcination with water, stirring, standing and decanting, and repeating if necessary. The above operation.

Replacement page (Article 26)