Method for producing metatitanic acid by ammonium sulfate roasting method

Abstract

The invention discloses a technical scheme for producing metatitanic acid by an ammonium sulfate roasting method, and relates to the technical field of chemical engineering. The method comprises the following steps: crushing raw materials for later use; wherein the raw material is one or more of a titanate-containing substance and a titaniferous oxide-containing substance; mixing the crushed raw materials with ammonium sulfate crystals, and carrying out roasting reaction; putting a substance obtained after the roasting reaction into a dissolving solution, stirring, dissolving and filtering; wherein the dissolving solution is one of water and sulfate liquid; and adjusting the filtrate obtained after filtration to weak acidity, carrying out a neutralization reaction, then heating, carrying out a hydrolysis reaction, and then filtering. According to the invention, the subsequent mature process route of the sulfuric acid method is continued, the process links required by the product are fully met, and meanwhile, the problems of environmental protection, energy consumption, cost, technical difficulty and the like in the conventional titanium dioxide production method are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical industry, in particular to a method for producing metatitanic acid, an intermediate in the production of titanium dioxide. Background Art

[0002] Titanium dioxide, a key inorganic chemical pigment, is widely used in numerous industrial sectors, including coatings, plastics, papermaking, and inks, with continued market demand. Currently, the two most mature methods for producing titanium dioxide are the sulfuric acid process and the chlorination process. However, both methods have limitations, driving the industry's exploration of new production technologies, particularly innovative methods for preparing metatitanic acid.

[0003] Among them, the sulfuric acid method is the traditional titanium dioxide production process. Its basic process is: first, use sulfuric acid to decompose titanium ore to obtain titanium oxysulfate (TiOSO4) solution; then purify and concentrate the titanium liquid, and then hydrolyze the purified and concentrated titanium liquid to produce titanic acid (TiO2•H2O); the titanic acid is then washed, filtered, calcined and other processes, and finally surface treated to produce the finished titanium dioxide product.

[0004] However, the sulfuric acid method has significant drawbacks. During the production process, it produces large amounts of "three wastes"—waste acid, waste residue, and wastewater—which place significant pressure on the environment. Furthermore, the process consumes large amounts of sulfuric acid, which not only increases raw material costs, but also further increases production costs due to subsequent waste acid treatment.

[0005] The chloride process uses natural rutile, synthetic rutile, or high-titanium slag as raw materials. After a complex series of processes, including chlorination, refining, oxidation, and surface treatment, titanium dioxide is produced. Compared to the sulfuric acid process, the chloride process offers certain environmental advantages, with relatively low emissions of the three wastes.

[0006] However, the chlorination process also presents numerous challenges. The process involves multiple disciplines and expertise, is technically challenging, and requires extremely stringent control of parameters such as temperature, pressure, and raw material purity during production. Furthermore, the key equipment required for chlorination production is complex and expensive to manufacture and maintain, which to some extent limits its widespread adoption.

[0007] In view of the above-mentioned problems existing in the existing titanium dioxide production method, it is urgent to develop a new production process that is expected to solve the various drawbacks of the existing process. Summary of the Invention

[0008] The present invention provides a technical solution for producing metatitanic acid by an ammonium sulfate roasting method, which not only continues the mature process route subsequent to the sulfuric acid method and fully meets the process links required by the product, but also solves the problems of environmental protection, energy consumption, cost, technical difficulty and so on in the existing traditional titanium dioxide production methods.

[0009] To achieve the above object, the technical solution adopted by the present invention is: It includes the following steps: A. crushing the raw materials for standby use; wherein the raw materials are one or more of titanate-containing substances and titanium oxide-containing substances; B. mixing the raw material crushed in step A with ammonium sulfate crystals and performing a roasting reaction; C. placing the substance obtained after the calcination reaction in step B into a dissolving solution, stirring, dissolving, and filtering; wherein the dissolving solution is one of water and sulfate liquid; D. The filtrate obtained after filtering in step C is adjusted to weak acidity for neutralization reaction, then heated for hydrolysis reaction, and filtered.

[0010] In the above technical solution, a more specific technical solution may also be: in step A, the raw material is one or more of titanium concentrate, acid-soluble slag, and high-titanium slag.

[0011] Furthermore, in step B, the temperature of the calcination reaction is 300°C to 500°C.

[0012] Furthermore, in step C, the sulfate liquid is ammonium sulfate liquid, and the ammonium sulfate liquid has a pH of 1.5 and a concentration of 30 wt%.

[0013] Furthermore, in step D, the filtrate is adjusted to weak acidity with a base for neutralization reaction.

[0014] Furthermore, the base is aqueous ammonia.

[0015] Furthermore, the metatitanic acid is used to produce titanium dioxide.

[0016] Due to the adoption of the above technical solution, the present invention has the following beneficial effects compared with the prior art: 1. Compared with the complex production processes of the existing sulfuric acid method and chlorination method, the production process of the present invention is more simplified, reducing production links, improving production efficiency, and reducing uncertainty and risk in the production process. At the same time, the existing chlorination method involves multiple disciplines and professional knowledge, is technically difficult, and has extremely strict control requirements for parameters such as temperature, pressure, and raw material purity during the production process. However, the production technology of the present invention is less difficult, does not require the use of complex equipment, has relatively low technical requirements for operators, and is more suitable for large-scale promotion and application.

[0017] 2. The raw materials of the present invention are more widely adaptable. One or more of titanium concentrate, acid-soluble slag, and high-titanium slag can be used as raw materials. The valuable components are easy to separate and recover, and the resource utilization rate is greatly improved. It can fully utilize resources, reduce resource waste, and further improve economic benefits.

[0018] 3. The waste residue produced by the process of the present invention can be sorted and recovered to produce valuable by-products such as iron oxides. These by-products can create additional economic value and improve the economic benefits of the production process.

[0019] 4. The present invention is combined with the existing efficient ammonium sulfate concentration and crystallization technology, so that the ammonium sulfate solution produced in the process can basically be returned to the process, eliminating the need to consume large amounts of other sulfuric acid, hydrochloric acid, and chlorine, effectively reducing the cost of raw materials; at the same time, the production process is simplified, various expenses in the production process are reduced, and the overall production cost is significantly reduced.

[0020] 5. The ammonium sulfate roasting method adopted in the present invention can separate the waste residue to recover valuable by-products such as iron oxides, and basically no large amount of waste is discharged, which greatly reduces the pollution to the environment. The production environment is cleaner and more pleasant, which meets the current green and environmentally friendly industrial development requirements.

[0021] 6. The present invention does not need to consume a large amount of harmful substances such as sulfuric acid, hydrochloric acid, chlorine, etc., which reduces the use and discharge of harmful substances from the source and reduces the potential harm to the ecological environment. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below with reference to examples.

[0023] Example 1 Step (1): crush the titanium concentrate to 300 mesh, and measure the TiO2 content to be 51.3%; Step (2): Take 40 g of the material obtained in step (1) as a raw material, add 100 g of ammonium sulfate crystals, mix the two, put them into a porcelain crucible, and then put it into a crucible furnace at 400 degrees for 5 hours, cool it down and take it out; Step (3): Place the material obtained in step (2) into 2L of ammonium sulfate liquid with a pH of about 1.5 and a concentration of 30%, stir for 2 hours to fully dissolve it, and then filter; Step (4): The filtrate obtained in step (3) is first adjusted to a pH of about 5 with aqueous ammonia for neutralization reaction; then heated and stirred for about 2 hours for hydrolysis reaction, and finally filtered and washed to obtain 22 g of titanic acid.

[0024] Example 2 Step (1): crush the acid-soluble slag from a certain place into 250 mesh, and measure the TiO2 content to be 73.8%; Step (2): Take 20 g of the material obtained in step (1) as a raw material, add 70 g of ammonium sulfate crystals, mix the two, put them into a porcelain crucible, and then put it into a crucible furnace at 390 degrees for 4 hours, cool it down and take it out; Step (3): Place the material obtained in step (2) into 1.5 L of water, stir for 2 hours, and then filter; Step (4): The filtrate obtained in step (3) was first adjusted to a pH of about 5 with aqueous ammonia for neutralization reaction; then heated and stirred for about 2 hours for hydrolysis reaction, and finally filtered and washed to obtain 15.8 g of titanic acid.

[0025] Example 3 Step (1): crush the high-titanium slag from a certain place to 200 mesh, and measure the TiO2 content to be 89.6%; Step (2): Take 20 g of the material obtained in step (1) as a raw material, add 80 g of ammonium sulfate crystals, mix the two, put them into a porcelain crucible, and then put it into a crucible furnace at 380 degrees to keep it warm for 4 hours, and take it out after cooling; Step (3): Place the material obtained in step (2) into 2 L of water, stir for 2 hours, and then filter; Step (4): The filtrate obtained in step (3) was first adjusted to a pH of about 5 with aqueous ammonia for neutralization reaction; then heated and stirred for about 2 hours for hydrolysis reaction, and finally filtered and washed to obtain 19.2 g of titanic acid.

[0026] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. The ammonium sulfate roasting method is used to produce titanic acid, which is characterized by The following steps are involved: A. crushing the raw materials for standby use; wherein the raw materials are one or more of titanate-containing substances and titanium oxide-containing substances; B. mixing the raw material crushed in step A with ammonium sulfate crystals and performing a roasting reaction; C. placing the substance obtained after the calcination reaction in step B into a dissolving solution, stirring, dissolving, and filtering; wherein the dissolving solution is one of water and sulfate liquid; D. The filtrate obtained after filtering in step C is adjusted to weak acidity for neutralization reaction, then heated for hydrolysis reaction, and filtered.

2. The ammonium sulfate roasting method for producing metatitanic acid according to claim 1, characterized in that: In step A, the raw materials are one or more of titanium concentrate, acid-soluble slag, and high-titanium slag.

3. The ammonium sulfate roasting method for producing metatitanic acid according to claim 1 or 2, characterized in that: In step B, the temperature of the calcination reaction is 300°C to 500°C.

4. The ammonium sulfate roasting method for producing metatitanic acid according to claim 3, characterized in that: In step C, the sulfate liquid is ammonium sulfate liquid, and the ammonium sulfate liquid has a pH of 1.5 and a concentration of 30 wt%.

5. The ammonium sulfate roasting method for producing metatitanic acid according to claim 4, characterized in that: In step D, the filtrate is adjusted to weak acidity with a base for neutralization reaction.

6. The ammonium sulfate roasting method for producing metatitanic acid according to claim 5, characterized in that: The base is aqueous ammonia.

7. The ammonium sulfate roasting method for producing metatitanic acid according to claim 6, characterized in that: The metatitanic acid is used to produce titanium dioxide.