A method for producing crystalline titanium sulfate

Abstract

The application relates to a preparation method of crystalline titanium sulfate, and steps are as follows: 2-2.5 parts of 90% concentrated sulfuric acid are taken, 1 part of 98% titanium white powder or 2 parts of 56% hydrated titanium dioxide is slowly added, and an exothermic reaction is carried out; when the temperature reaches 90-100 DEG C or 140-145 DEG C, the reaction is continued for 48 hours; after filtration, 1 part of 75%-80% sulfuric acid is slowly added for acidification reaction to 120-125 DEG C, and stirring is carried out during the adding, until a viscous reaction product is obtained; cooling and crystallization are carried out, and titanium sulfate crystals are obtained. The application solves the problems of long dissolving time of titanium sulfate and easy hydrolysis, and the problems of high cost, complex process and low product purity in direct preparation of titanium sulfate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of titanium sulfate, in particular to a preparation method of crystalline titanium sulfate. BACKGROUND

[0002] The existing similar product of titanium sulfate in China is titanyl sulfate, which is obtained by reacting titanium dioxide and sulfuric acid. The existing titanium sulfate production process is complex, the cost is higher than that of titanyl sulfate, the market sales price is also nearly 1 times higher than that of titanyl sulfate, so titanyl sulfate is more commonly used in the market. Titanyl sulfate is an inorganic substance with the chemical formula TiOSO4, which is soluble in water and easily hydrolyzed in hot water. It is used as a mordant, a catalyst, a reducing agent, a dye fading agent, etc.; it can also be used for electroplating. The disadvantage of titanyl sulfate in application is that it is easily hydrolyzed and dissolves too slowly.

[0003] In the traditional production process of titanium sulfate, liquid H2SO4 is mostly used. Because H2SO4 is strongly acidic and has dehydration and oxidation properties, there are many side reactions in production and the discharge amount of "three wastes" is large, which causes great pressure on environmental protection. The existing titanium sulfate, such as titanium tetrabromide reacting with concentrated sulfuric acid, or titanyl potassium oxalate reacting with concentrated sulfuric acid, has bromine and potassium participating in the reaction of sulfuric acid, which affects the content of titanium sulfate, greatly increases the production cost, and affects the economic benefit. The commercially available titanium sulfate has been tested to have an asymmetric molecular structure, which is an intermediate between titanium sulfate and titanyl sulfate, and is not pure titanium sulfate, which does not meet the process requirements. SUMMARY

[0004] The present application provides a preparation method of crystalline titanium sulfate. The present application proposes a preparation method of titanium sulfate based on titanyl sulfate, which solves the problems of long dissolution time and easy hydrolysis of titanyl sulfate, and the problems of high cost, complex process, and low product purity in direct preparation of titanium sulfate.

[0005] Technical scheme:

[0006] The present application provides a preparation method of crystalline titanium sulfate, the steps are as follows:

[0007] Take 2-2.5 parts of 90% concentrated sulfuric acid, and slowly add 1 part of 98% titanium dioxide or 2 parts of 56% hydrous titanium dioxide to carry out exothermic reaction. When the temperature reaches 90-100 degrees Celsius or 140-145 degrees Celsius, react for another 48 hours. After filtration, slowly add 1 part of 75%-80% sulfuric acid to acidify the reaction to 120-125 degrees Celsius, and stir while adding until a sticky reaction product is obtained. After cooling and crystallization, titanium sulfate crystals are obtained.

[0008] Preferably, in the step, 90% concentrated sulfuric acid is 2 parts, 98% titanium dioxide is 1 part, and 75% sulfuric acid is 1 part.

[0009] Preferably, in the step, when 1 part of 98% titanium dioxide is added, the temperature of the exothermic reaction reaches 90-100 degrees Celsius, and then the reaction is continued for 48 hours.

[0010] Preferably, in the step, when 2 parts of 56% titanium dioxide are added, the temperature of the exothermic reaction reaches 140-145 degrees Celsius, and then the reaction is continued for 48 hours.

[0011] Beneficial effects:

[0012] The titanium sulfate of the present application has a fast dissolution rate and is not prone to hydrolysis compared to titanyl sulfate; and the reaction conditions are relatively mild, saving reaction time, improving efficiency, and the product has more stable properties. The titanium sulfate of the present application is strictly made according to the titanium sulfate reaction equation, has a symmetrical molecular structure, and can meet various indicators according to the equation. The production process is simple and the production cost is low. DETAILED DESCRIPTION

[0013] The present application will be described in more detail below with reference to the examples.

[0014] The titanium sulfate of the present application is obtained by adding concentrated sulfuric acid to sulfuric acid and titanium dioxide or titanium dioxide during the reaction process. A method for preparing crystalline titanium sulfate, the steps are as follows:

[0015] Take 2-2.5 parts of 90% concentrated sulfuric acid, and slowly add 1 part of 98% titanium dioxide or 2 parts of 56% titanium dioxide, and perform an exothermic reaction. When the temperature reaches 90-100 degrees Celsius or 140-145 degrees Celsius, the reaction is continued for 48 hours. After filtration, 1 part of 75%-80% sulfuric acid is slowly added and acidified to 120-125 degrees Celsius, and stirring is continued until a viscous reaction product is obtained. After cooling and crystallization, titanium sulfate crystals are obtained.

[0016] The acid concentration of the centrifuge is 80% when the material is removed.

[0017] The reaction formula of the above reaction is as follows:

[0018] H2SO4+TiO2 exothermic → TiOSO4

[0019] TiOSO4+H2SO4 acidification → Ti(SO4)2.

[0020] In the above reaction process, the sulfuric acid mist produced is absorbed by ammonium bicarbonate to produce ammonium sulfate fertilizer, in order to avoid the impact of sulfuric acid mist on the environment.

[0021] Titanium sulfate is soluble in dilute acid, insoluble in water, and stable in nature, effectively avoiding the problem of easy hydrolysis of titanyl sulfate in application.

[0022] Example 1

[0023] Take 2 parts of 90% concentrated sulfuric acid and add it to a porcelain kettle, then slowly add 1 part of 98% titanium dioxide while stirring. During the reaction, heat will be released. When the temperature reaches 90-100 degrees Celsius, place it for 48 hours. After filtration, slowly add 1 part of 75% sulfuric acid to the kettle while stirring until the reaction becomes viscous. Cool and crystallize to obtain titanium sulfate crystals. Use a centrifuge to remove the acid, crush, package, and the yield reaches 72%. The acid concentration removed by the centrifuge is 80% and is used as a raw material.

[0024] Example 2

[0025] Take 2.5 parts of 90% concentrated sulfuric acid and add it to a porcelain kettle, then slowly add 1 part of 98% titanium dioxide while stirring. During the reaction, heat will be released. When the temperature reaches 90-100 degrees Celsius, place it for 48 hours. After filtration, the filtrate is placed into the porcelain kettle again, and then 1 part of 80% sulfuric acid is slowly added. The reaction temperature rises to 120 degrees Celsius, and the acid is added while stirring until the reaction becomes viscous. Cool and crystallize to obtain titanium sulfate crystals. Use a centrifuge to remove the acid, crush, package, and the yield reaches 67%. The acid concentration removed by the centrifuge is 80% and is used as a raw material.

[0026] Example 3

[0027] Take 2 parts of 90% concentrated sulfuric acid and add it to a porcelain kettle, then slowly add 2 parts of 56% titanium dioxide while stirring. During the reaction, heat will be released. When the reaction temperature rises to 140 degrees Celsius, place it for 48 hours. After filtration, the filtrate is placed into the porcelain kettle, and then 1 part of 75% sulfuric acid is slowly added. The reaction temperature rises to 120 degrees Celsius, and the acid is added while stirring until the reaction becomes viscous. Cool and crystallize to obtain titanium sulfate crystals. Use a centrifuge to remove the acid, crush, package, and the yield reaches 51%. The acid concentration removed by the centrifuge is used as a raw material.

[0028] Example 4

[0029] Take 2.5 parts of 90% concentrated sulfuric acid and add it to a porcelain kettle, then slowly add 2 parts of 56% titanium dioxide while stirring. During the reaction, heat will be released. When the reaction temperature rises to 140 degrees Celsius, place it for 48 hours. After filtration, the filtrate is placed into the porcelain kettle, and then 1 part of 75% sulfuric acid is slowly added. The reaction temperature rises to 120 degrees Celsius, and the acid is added while stirring until the reaction becomes viscous. Cool and crystallize to obtain titanium sulfate crystals. Use a centrifuge to remove the acid, crush, package, and the yield reaches 51%. The acid concentration removed by the centrifuge is used as a raw material.

[0030] Example 5: detection method

[0031] Titanium sulfate Ti(SO4)2content determination:

[0032] Take 0.2-0.3 of the sample of any one of the above Examples 1-4, add to a triangular flask, add distilled water 100 ml, add to boiling on an electric stove for 10 minutes, make it completely hydrolyzed metatitanic acid, take off and cool to room temperature, add 5 drops of phenolphthalein indicator, titrate with sodium hydroxide standard solution to stable red as the end point.

[0033] Analysis results:

[0034] The total sulfuric acid content X1(in mass percent) in titanium sulfate Ti(SO4)2is calculated as follows:

[0035]

[0036] In the formula: c----sodium hydroxide standard solution concentration, mol / L;

[0037] V---sodium hydroxide standard solution, mL;

[0038] G---sample weight, g;

[0039] The titanium sulfate Ti(SO4)2content X2is calculated as follows:

[0040] X2=(X1-X3)·383.76

[0041] In the formula: X1---total sulfuric acid content in titanium sulfate;

[0042] X3----free sulfuric acid content in titanium sulfate;

[0043] 383.76---the coefficient of titanium sulfate combined with titanium, converted into titanium oxysulfate.

[0044] The moisture content X4(indicated by mass percent) is calculated as follows:

[0045]

[0046] In the formula: W---weight after drying, g;

[0047] G---sample weight, g.

[0048] Table 1 verification data in Examples 1-4 of the application

[0049] X1 X2 X3 X4 Example 1 47.52％ 98.24％ 21.92％ 1.79％ Example 2 47.85％ 99.74％ 21.86％ 1.82％ Example 3 48.02％ 99.93％ 21.98％ 1.85％ Example 4 46.74％ 99.85％ 20.72％ 1.83％

[0050] As can be seen from the data in Table 1, the titanium sulfate prepared by the method has high purity.

[0051] Example 6: Dissolution rate comparison test

[0052] Test method: 20 grams of each of the titanium sulfate prepared according to Examples 1-4 of the present application and titanyl sulfate were taken, the titanium sulfate prepared according to the present application was added to 200 grams of 10% sulfuric acid solution, the titanyl sulfate was added to 200 grams of water, the same stirring speed was used, and the temperature was 20 degrees Celsius, stirring was performed until complete dissolution, and the time was recorded. The ambient temperature was 20 degrees Celsius.

[0053] Test results: Example 1 took 260 seconds, Example 2 took 250 seconds, Example 3 took 300 seconds, Example 4 took 320 seconds, and titanyl sulfate took 18 hours.

[0054] Test conclusion: The dissolution time of the titanium sulfate prepared according to the present method is greatly shortened compared to titanyl sulfate.

Claims

1. A method for producing crystalline titanium sulfate, characterized by, The procedure is as follows: Take 2-2.5 parts of 90% concentrated sulfuric acid and slowly add 1 part of 98% titanium white powder or 2 parts of 56% hydrated titanium dioxide to cause an exothermic reaction, When 1 part of 98% titanium white powder is added, the temperature of the exothermic reaction reaches 90-100 degrees Celsius, and the reaction is continued for 48 hours; Or, when 2 parts of 56% hydrated titanium dioxide are added, the temperature of the exothermic reaction reaches 140-145 degrees Celsius, and the reaction is continued for 48 hours; After filtration, 1 part of 75%-80% sulfuric acid is slowly added to the acidification reaction to 120-125 degrees Celsius, and stirring is continued until a viscous reaction product is obtained, which is cooled and crystallized to obtain titanium sulfate crystals.

2. The method for preparing crystalline titanium sulfate according to claim 1, characterized in that, In the procedure, 2 parts of 90% concentrated sulfuric acid, 1 part of 98% titanium white powder, and 1 part of 75% sulfuric acid are used.

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