阅读说明：本技术 一种液相加成生产氧化铁黑的方法 (Method for producing iron oxide black by liquid phase synthesis ) 是由 单淼 陆云飞 张明 于 2021-09-06 设计创作，主要内容包括：本发明公开了一种液相加成生产氧化铁黑的方法,属于氧化铁系颜料生产技术领域。本发明提供的液相加成生产氧化铁黑的方法,主要包括：在同一反应釜中,进行若干批次氧化铁黑生产,每次均保留上一批次生成的氧化铁黑,作为下一批次氧化铁黑生成的晶核；每个批次的氧化铁黑生产的具体方法为：将硫酸亚铁溶液和碱液预热后,加入反应釜中,维持温度70-95℃,通入空气后生成氧化铁黑,反应结束后,使氧化铁黑沉降,撇去上清。实验证明,本发明的方法,能提高氧化铁黑的化学稳定性及其色度品质,有效提升了氧化铁黑产品的质量,具有极高的工业应用价值。(The invention discloses a method for producing iron oxide black by liquid phase synthesis, belonging to the technical field of iron oxide pigment production. The invention provides a method for producing iron oxide black by liquid phase addition, which mainly comprises the following steps: in the same reaction kettle, a plurality of batches of iron oxide black are produced, and the iron oxide black generated in the previous batch is reserved each time and is used as a crystal nucleus generated by the iron oxide black in the next batch; the specific method for producing the iron oxide black of each batch comprises the following steps: preheating ferrous sulfate solution and alkali liquor, adding into a reaction kettle, maintaining the temperature at 70-95 ℃, introducing air to generate iron oxide black, settling the iron oxide black after the reaction is finished, and skimming supernatant. Experiments prove that the method can improve the chemical stability and the chromaticity quality of the iron oxide black, effectively improve the quality of the iron oxide black product and have extremely high industrial application value.)

1. The liquid phase synthesis process of producing black iron oxide features that several batches of black iron oxide are produced in the same reactor while maintaining the black iron oxide produced in the previous batch as the crystal nucleus for the next batch.

2. The method for producing black iron oxide through liquid phase addition according to claim 1, wherein the specific method for producing each batch of black iron oxide is as follows: preheating ferrous sulfate solution and alkali liquor, adding into a reaction kettle, maintaining the temperature at 70-95 ℃, introducing air to generate iron oxide black, settling the iron oxide black after the reaction is finished, and skimming supernatant.

3. The method for producing black iron oxide by liquid phase addition according to claim 2, wherein the temperature of the preheating is 70 ℃.

4. The method for producing black iron oxide by liquid phase addition according to claim 2, wherein the air is introduced at a rate of 25 to 35M³/min。

5. The method for producing black iron oxide by liquid phase addition according to claim 2, wherein the concentration of the ferrous sulfate solution is 0.5 to 10%.

6. The method for producing black iron oxide by liquid phase addition according to claim 2, wherein the number of batches is 5 to 8 batches.

Technical Field

The invention belongs to the technical field of production of iron oxide pigments, and particularly relates to a method for producing iron oxide black by liquid phase synthesis.

Background

Black iron oxide with molecular formula of Fe₃O₄Black powder of Fe₂O₃The addition product of FeO and FeO is insoluble in water, has magnetism, high coloring power and covering power, no toxicity and no pollution. The iron oxide black is used as an industrial raw material, is widely applied to the technical fields of coatings, cosmetics and biomedicines, and has wide development prospect.

The current common production process of iron oxide black in China mainly comprises the following steps:

an addition method comprises the following steps: mixing ferrous sulfate solution with liquid alkali (NaOH) and reactingShould produce Fe (OH)₂Adding proper amount of iron yellow leftover (FeSO) in proportion₃) Performing an addition reaction at 95-100 deg.C (reaction time about 68h) to obtain iron oxide black. The method has the defects of long reaction time, high energy consumption and light coloring power of the product.

A precipitation oxidation method: neutralizing the purified ferrous sulfate solution with liquid alkali to generate Fe (OH)₂And then heating to 85-95 ℃, introducing air for oxidation (having a stirring function) to obtain iron oxide black slurry, and filtering, washing, drying, finely grinding and blending to obtain an iron oxide black product. The direct oxidation method is an innovation for the addition method, and the coloring of the product is higher than that of the addition method.

An ammonia method: adding ammonia water into the purified ferrous sulfate solution, and controlling the pH of the solution to be about 9-10 to obtain a solution containing Fe (OH)₂And (NH)₄)₂SO₄The colloidal solution of (4). Then heating to 70-80 ℃, introducing air for oxidation (having a stirring function) to obtain iron oxide black slurry, and filtering, washing, drying, finely grinding and blending to obtain an iron oxide black product; the filtrate is evaporated to prepare ammonium sulfate. Although the quality of the iron oxide black prepared by the method can reach the national first-grade product standard, the production cost is reduced, and the by-product (NH) is generated₄)₂5O₄Can be recycled as fertilizer, but has certain environmental pollution because the volatilization of free ammonia in the solution is inevitably caused in the production process.

The precipitation oxidation method is the most used iron oxide black production method at present by combining various factors, but can be improved according to the change of specific production conditions, and has the possibility of improving the production efficiency and the product quality.

Disclosure of Invention

In view of the above problems in the prior art, the technical problem to be solved by the present invention is to provide a method for producing black iron oxide by liquid phase synthesis.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

a method for producing black iron oxide by liquid phase synthesis comprises the following steps: and (3) carrying out a plurality of batches of black iron oxide production in the same reaction kettle, and keeping the black iron oxide produced in the previous batch each time to be used as a crystal nucleus for the production of the black iron oxide in the next batch.

Further, the specific method for producing the iron oxide black of each batch comprises the following steps: preheating ferrous sulfate solution and alkali liquor, adding into a reaction kettle, maintaining the temperature at 70-95 ℃, introducing air to generate iron oxide black, settling the iron oxide black after the reaction is finished, and skimming supernatant.

Further, the temperature of the preheating is 70 ℃.

Further, the air introducing speed is 25-35M³/min。

Further, the concentration of the ferrous sulfate solution is 0.5-10%.

Further, the plurality of batches are 5-8 batches.

Compared with the prior art, the invention has the beneficial effects that:

the method for producing the iron oxide black through liquid phase addition, provided by the invention, is characterized in that a plurality of batches of iron oxide black production are carried out in the same reaction kettle, the iron oxide black generated in the previous batch is reserved each time and is used as a crystal nucleus generated by the iron oxide black in the next batch, and the steps are repeated, so that the chemical stability and the chromaticity quality of the iron oxide black are improved, the quality of the iron oxide black product is effectively improved, and the method has a very high industrial application value. The method can particularly effectively recover and utilize low-concentration ferrous sulfate, and the existing method for producing 1 ton of iron oxide red can generate a large amount of about 20 tons of mother liquor (also called process water and waste water), wherein the main components of the mother liquor are ferrous sulfate with the content of about 0.5 percent and other miscellaneous salts. The method of the invention can further utilize the ferrous sulfate in the mother liquor with high efficiency.

Detailed Description

The invention is further described with reference to specific examples.

Example 1:

adding 0.5% ferrous sulfate solution preheated to 70 deg.C into reaction kettle, maintaining at 70-95 deg.C, introducing 25M air³Adding NaOH solution, ferrous sulfate and sodium hydroxide under the condition of minForming reaction to generate ferroferric oxide, stopping stirring after the reaction is finished, settling and gathering the ferroferric oxide at the bottom of the reaction kettle, removing supernatant after the settling is finished, keeping the generated ferroferric oxide in the reaction kettle, continuously adding 0.5 percent ferrous sulfate solution preheated to 70 ℃ into the reaction kettle, adding NaOH solution, and introducing 25M of air³And/min, keeping the temperature at 70-95 ℃ to continuously generate ferroferric oxide. And performing reaction to generate ferroferric oxide-ferroferric oxide sedimentation-supernatant removal circulation for 3 times in a reaction kettle, collecting and cleaning the sediment, and performing conventional filter pressing, drying and grinding to obtain the iron oxide black.

Example 2:

adding 0.5% ferrous sulfate solution preheated to 70 deg.C into reaction kettle, maintaining at 80-95 deg.C, introducing air 30M³Adding NaOH solution under the condition of min, carrying out addition reaction on ferrous sulfate and sodium hydroxide to generate ferroferric oxide, stopping stirring after the reaction is finished, settling and gathering the ferroferric oxide at the bottom of the reaction kettle, removing supernatant after the settlement is finished, keeping the generated ferroferric oxide in the reaction kettle, continuously adding 0.5% ferrous sulfate solution preheated to 70 ℃ into the reaction kettle, adding NaOH solution, and introducing air at the rate of 30M³And/min, keeping the temperature at 70-95 ℃ to continuously generate ferroferric oxide. And performing reaction to generate ferroferric oxide-ferroferric oxide sedimentation-supernatant removal circulation for 5 times in a reaction kettle, collecting and cleaning the sediment, and performing conventional filter pressing, drying and grinding to obtain the iron oxide black.

Example 3:

adding 0.5% ferrous sulfate solution preheated to 70 deg.C into reaction kettle, maintaining at 80-95 deg.C, introducing air 30M³Adding NaOH solution under the condition of min, carrying out addition reaction on ferrous sulfate and sodium hydroxide to generate ferroferric oxide, stopping stirring after the reaction is finished, settling and gathering the ferroferric oxide at the bottom of the reaction kettle, removing supernatant after the settlement is finished, keeping the generated ferroferric oxide in the reaction kettle, continuously adding 0.5% ferrous sulfate solution preheated to 70 ℃ into the reaction kettle, adding NaOH solution, and introducing air at the rate of 30M³Min, keeping the temperature at 70-95 deg.CAnd generating ferroferric oxide. And performing reaction to generate ferroferric oxide-ferroferric oxide sedimentation-supernatant removal circulation for 8 times in a reaction kettle, collecting and cleaning the sediment, and performing conventional filter pressing, drying and grinding to obtain the iron oxide black.

Example 4:

adding 2% ferrous sulfate solution preheated to 70 deg.C into reaction kettle, maintaining at 70-95 deg.C, introducing air 30M³Adding NaOH solution under the condition of min, carrying out addition reaction on ferrous sulfate and sodium hydroxide to generate ferroferric oxide, stopping stirring after the reaction is finished, settling and gathering the ferroferric oxide at the bottom of the reaction kettle, removing supernatant after the settling is finished, keeping the generated ferroferric oxide in the reaction kettle, continuously adding 0.5% ferrous sulfate solution preheated to 70 ℃ into the reaction kettle, adding NaOH solution, introducing air, and keeping the temperature at 70-95 ℃ to continuously generate the ferroferric oxide. And performing reaction to generate ferroferric oxide-ferroferric oxide sedimentation-supernatant removal circulation for 6 times in a reaction kettle, collecting and cleaning the sediment, and performing conventional filter pressing, drying and grinding to obtain the iron oxide black.

Example 5:

adding 5% ferrous sulfate solution preheated to 70 deg.C into reaction kettle, maintaining at 70-95 deg.C, introducing air 30M³Adding NaOH solution under the condition of min, carrying out addition reaction on ferrous sulfate and sodium hydroxide to generate ferroferric oxide, stopping stirring after the reaction is finished, settling and gathering the ferroferric oxide at the bottom of the reaction kettle, removing supernatant after the settlement is finished, keeping the generated ferroferric oxide in the reaction kettle, continuously adding 0.5% ferrous sulfate solution preheated to 70 ℃ into the reaction kettle, adding NaOH solution, and introducing 30M air³And/min, keeping the temperature at 70-95 ℃ to continuously generate ferroferric oxide. And performing reaction to generate ferroferric oxide-ferroferric oxide sedimentation-supernatant removal circulation for 6 times in a reaction kettle, collecting and cleaning the sediment, and performing conventional filter pressing, drying and grinding to obtain the iron oxide black.

Example 6:

adding 10% ferrous sulfate solution preheated to 70 deg.C into reaction kettle, maintaining at 70-95 deg.C, introducingAir 30M³Adding NaOH solution under the condition of min, carrying out addition reaction on ferrous sulfate and sodium hydroxide to generate ferroferric oxide, stopping stirring after the reaction is finished, settling and gathering the ferroferric oxide at the bottom of the reaction kettle, removing supernatant after the settlement is finished, keeping the generated ferroferric oxide in the reaction kettle, continuously adding 0.5% ferrous sulfate solution preheated to 70 ℃ into the reaction kettle, adding NaOH solution, and introducing air at the rate of 30M³And/min, keeping the temperature at 70-95 ℃ to continuously generate ferroferric oxide. And performing reaction to generate ferroferric oxide-ferroferric oxide sedimentation-supernatant removal circulation for 6 times in a reaction kettle, collecting and cleaning the sediment, and performing conventional filter pressing, drying and grinding to obtain the iron oxide black.

Example 7:

the iron oxide blacks prepared in examples 1 to 6 were tested for stability and color index, and it was found that in examples 1 to 3, the stability of the iron oxide black gradually increased with the increase of the number of cycles, but the color index of the iron oxide blacks in examples 2 and 3 was better than that in example 1, and the color was more pure black. In examples 4 to 6, the stability of the iron oxide black is slightly reduced with the increase of the concentration of the ferrous sulfate solution to 10%, and the color index is slightly different between the concentration of the ferrous sulfate solution of 2% and the concentration of the ferrous sulfate solution of 5%, which is slightly lower than that of example 2 and slightly better than that of example 6.