阅读说明：本技术 一种水泥窑用后砖中氯化钾的去除方法 (Method for removing potassium chloride in bricks used in cement kiln ) 是由 田琳 贾小东 毛硕 谢永涣 李国华 于 2020-12-30 设计创作，主要内容包括：本发明公开了一种水泥窑用后砖中氯化钾的去除方法,该方法的实施过程包括制粉、配置复合酸溶液、浸泡、过滤和干燥等步骤,氯化钾的去除率最高可达99.856％。本发明采用的试剂原料价格低廉,处理工艺简单,只需要通过浸泡过滤即可实现水泥窑用后砖中氯化钾的去除,氯化钾去除效率高,处理成本低,易于实现工业化应用。最终得到的再生复相镁砂细粉中氯化钾含量仅为0.005％,可作为建材或耐火材料的生产原料,实现了不可再生资源镁砂的可持续利用,有效解决了水泥窑用后砖堆放污染环境的问题,可产生显著的经济和社会效益。(The invention discloses a method for removing potassium chloride in a brick used in a cement kiln, which comprises the steps of pulverizing, preparing a composite acid solution, soaking, filtering, drying and the like, wherein the removal rate of potassium chloride can reach 99.856 percent at most. The reagent adopted by the invention has low price of raw materials and simple treatment process, can remove potassium chloride in the brick used in the cement kiln only by soaking and filtering, has high potassium chloride removal efficiency and low treatment cost, and is easy to realize industrial application. The potassium chloride content in the finally obtained regenerated complex-phase magnesite fine powder is only 0.005%, the regenerated complex-phase magnesite fine powder can be used as a production raw material of building materials or refractory materials, the sustainable utilization of non-renewable resource magnesite is realized, the problem that bricks are piled up and pollute the environment after the cement kiln is used is effectively solved, and remarkable economic and social benefits can be generated.)

1. A method for removing potassium chloride in bricks used in a cement kiln is characterized by comprising the following steps:

(1) removing a deteriorated layer on the surface of a brick for the cement kiln by manual selection, roughly crushing the selected brick for the cement kiln to 10-20mm by a jaw crusher, crushing the brick to be less than 0.5mm by a cone crusher or a double-roller crusher, and then grinding the brick to be 0.074-0.044mm by a vertical pulverizer to prepare powder;

(2) preparing 0.05-1mol/L nitric acid and 0.05-1mol/L organic acid into a composite acid solution at room temperature according to the mass ratio of 1: 1-1: 10;

(3) uniformly mixing the powder obtained in the step (1) and the composite acid solution prepared in the step (2) according to the mass ratio of 1: 1-1: 6, and soaking at 25 ℃ for 12-48 hours to obtain a mixed solution;

(4) and (4) removing supernatant of the mixed solution obtained in the step (3), repeatedly washing and filtering the precipitate for 2-5 times by using tap water, and drying the filtered precipitate in a drying kiln or an oven at the temperature of 100 ℃ and 200 ℃ for 12-24 hours to obtain the regenerated complex-phase magnesia fine powder.

2. The method for removing potassium chloride in the bricks after cement kiln use as claimed in claim 1, wherein the organic acid comprises one or more of citric acid, malic acid and tartaric acid, and the concentration of citric acid, malic acid and tartaric acid is 0.05-1 mol/L.

3. The method for removing potassium chloride in the bricks used in the cement kiln as claimed in claim 2, wherein when the organic acid is a mixture of a plurality of organic acids, there are three mixing modes, respectively, the mass ratio of citric acid to malic acid is 2: 1-9: 1; the mass ratio of the citric acid to the tartaric acid is 5: 2-9: 1; the mass ratio of the citric acid to the malic acid to the tartaric acid is 10:1: 1-10: 3: 3.

4. The method for removing potassium chloride from cement kiln after-bricks according to claim 1, wherein the cement kiln after-bricks comprise periclase-hercynite bricks, periclase-magnesium aluminate spinel bricks and high-iron magnesia bricks.

5. The method for removing potassium chloride from the bricks used in the cement kiln as claimed in claim 1, wherein the regenerated complex phase magnesite fine powder can be used as a raw material of an alkaline refractory product or a building material product.

Technical Field

The invention belongs to the technical field of treatment and recycling of used refractory materials, and particularly relates to a method for removing potassium chloride from used bricks of a cement kiln.

Background

China is a big cement producing country, 22.1 hundred million tons of cement are produced in 2018 year in a symbiotic manner and account for 56 percent of the total world production, a large amount of used refractory materials are produced in the cement producing process, and the used bricks of the cement kiln are one of the bricks. As the bricks used in the cement kiln contain potassium chloride, the direct reuse of the bricks has the problems of low refractoriness under load, poor high-temperature creep property, hot brittleness, short service life and the like. At present, the treatment method of the bricks used in the cement kiln is mainly landfill or random disposal, which not only pollutes the environment, but also wastes non-renewable resources such as magnesia and the like, separates and removes potassium chloride in the bricks used in the cement kiln, improves the reutilization rate and application effect of the bricks used in the cement kiln, is a key for recycling and reusing the bricks, and is an urgent technology in the cement industry.

At present, no relevant report is provided for the process for removing potassium chloride in the bricks after the cement kiln is used. CN201511005271.7

The method for extracting potassium chloride from sintered ash mentions that potassium chloride can be extracted by using a leaching solution prepared from a leaching modifier, but the process for preparing the solution is complex, and the solution contains a large amount of metal salts, so that the method is not suitable for removing the potassium chloride in the bricks after the cement kiln is used.

Disclosure of Invention

The invention aims to provide a method for removing potassium chloride in bricks after cement kiln use, which has the advantages of simple process, high potassium chloride removal efficiency and low treatment cost, and is suitable for removing potassium chloride in bricks after cement kiln use in large-scale industrial production.

In order to achieve the purpose, the invention is realized by adopting the following technical scheme.

A method for removing potassium chloride in bricks used in a cement kiln comprises the following steps:

(1) removing a deteriorated layer on the surface of a brick for the cement kiln by manual selection, roughly crushing the selected brick for the cement kiln to 10-20mm by a jaw crusher, crushing the brick to be less than 0.5mm by a cone crusher or a double-roller crusher, and then grinding the brick to be 0.074-0.044mm by a vertical pulverizer to prepare powder;

(2) preparing 0.05-1mol/L nitric acid and 0.05-1mol/L organic acid into a composite acid solution at room temperature according to the mass ratio of 1: 1-1: 10;

(3) uniformly mixing the powder obtained in the step (1) and the composite acid solution prepared in the step (2) according to the mass ratio of 1: 1-1: 6, and soaking at 25 ℃ for 12-48 hours to obtain a mixed solution;

(4) and (4) removing supernatant of the mixed solution obtained in the step (3), repeatedly washing and filtering the precipitate for 2-5 times by using tap water, and drying the filtered precipitate in a drying kiln or an oven at the temperature of 100 ℃ and 200 ℃ for 12-24 hours to obtain the regenerated complex-phase magnesia fine powder.

The organic acid comprises one or more of citric acid, malic acid and tartaric acid, and the concentrations of citric acid, malic acid and tartaric acid are all 0.05-1 mol/L.

When the organic acid is a mixture of multiple organic acids, three mixing modes are provided, wherein the mass ratio of citric acid to malic acid is 2: 1-9: 1; the mass ratio of the citric acid to the tartaric acid is 5: 2-9: 1; the mass ratio of the citric acid to the malic acid to the tartaric acid is 10:1: 1-10: 3: 3.

The cement kiln rear brick comprises a periclase-hercynite brick, a periclase-magnesium aluminate spinel brick and a high-iron magnesia brick.

The regenerated complex phase magnesia fine powder can be used as a raw material of an alkaline refractory product or a building material product.

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

the reagent adopted by the invention has low price of raw materials and simple treatment process, can remove potassium chloride in the brick used in the cement kiln only by soaking and filtering, has high potassium chloride removal efficiency and low treatment cost, and is easy to realize industrial application. The content of potassium chloride in the regenerated complex-phase magnesite fine powder meets the national standard requirement, can be used as a production raw material of building materials or refractory materials, realizes the sustainable utilization of non-renewable resource magnesite, effectively solves the problem that bricks are piled up to pollute the environment after the cement kiln is used, and can generate remarkable economic and social benefits.

Detailed Description

The present invention will be described in detail with reference to specific examples, which are not intended to limit the scope of the present invention in any way.

[ example 1 ]

A method for removing potassium chloride in bricks used in a cement kiln comprises the following steps:

(1) removing a deteriorated layer on the surface of a cement kiln rear brick (a rear magnesite-hercynite brick for a firing zone) through manual selection, roughly crushing the selected cement kiln rear brick to 10-20mm by using a jaw crusher, crushing the crushed brick to be less than 0.5mm by using a cone crusher or a pair roller crusher, and then grinding the crushed brick to be 0.074-0.044mm by using a vertical pulverizer to prepare powder (the potassium chloride content is 3.47 percent, and the magnesium oxide content is 81.50 percent);

(2) preparing a composite acid solution from 0.05-1mol/L nitric acid (0.05mol/L nitric acid 2kg) and 0.05-1mol/L organic acid (0.15mol/L citric acid 3kg) at room temperature according to the mass ratio of 1: 1.5;

(3) uniformly mixing the powder obtained in the step (1) with the composite acid solution prepared in the step (2) according to the mass ratio of 1:2 (2.5 kg of powder and 5kg of composite acid solution), and soaking for 24 hours at 25 ℃ to obtain a mixed solution;

(4) and (4) removing supernatant of the mixed solution obtained in the step (3), repeatedly washing and filtering the precipitate for 3 times (15kg of water) by using tap water, and drying the filtered precipitate in a drying kiln or an oven at 110 ℃ for 12h to obtain the regenerated complex-phase magnesia fine powder.

The content of potassium chloride in the sample is detected to be 0.010 percent, the content of magnesium oxide is 85.11 percent and the removal rate of potassium chloride is 99.712 percent by adopting X-ray fluorescence detection.

[ example 2 ]

Step (1) same as example 1;

(2) preparing a composite acid solution from 0.05-1mol/L nitric acid (0.5mol/L nitric acid 1kg) and 0.05-1mol/L organic acid (0.5mol/L citric acid 5kg and 0.1mol/L tartaric acid solution 2kg) at room temperature according to a mass ratio of 1: 7;

(3) uniformly mixing the powder obtained in the step (1) with the composite acid solution prepared in the step (2) according to the mass ratio of 1:3.2 (2.5 kg of powder and 8kg of composite acid solution), and soaking for 24 hours at 25 ℃ to obtain a mixed solution;

(4) and (4) removing supernatant of the mixed solution obtained in the step (3), repeatedly washing and filtering the precipitate for 3 times (15kg of water) by using tap water, and drying the filtered precipitate in a drying kiln or an oven at 110 ℃ for 24 hours to obtain the regenerated complex-phase magnesia fine powder.

The X-ray fluorescence detection is adopted to detect that the potassium chloride content in the sample is 0.021%, the magnesium oxide content is 84.24%, and the potassium chloride removal rate is 99.395%.

[ example 3 ]

Step (1) same as example 1;

(2) preparing a composite acid solution from 0.05-1mol/L nitric acid (1mol/L nitric acid 2kg) and 0.05-1mol/L organic acid (1mol/L citric acid 5kg, 1mol/L malic acid 1.5kg and 0.5mol/L tartaric acid 1.5kg) at room temperature according to a mass ratio of 1: 4;

(3) uniformly mixing the powder obtained in the step (1) with the composite acid solution prepared in the step (2) according to the mass ratio of 1:4 (2.5 kg of powder and 10kg of composite acid solution), and soaking at 25 ℃ for 24 hours to obtain a mixed solution;

(4) and (4) removing supernatant of the mixed solution obtained in the step (3), repeatedly washing and filtering the precipitate for 5 times (20kg of water) by using tap water, and drying the filtered precipitate in a drying kiln or an oven at 110 ℃ for 12h to obtain the regenerated complex-phase magnesia fine powder.

The content of potassium chloride in the sample is detected to be 0.014% by adopting X-ray fluorescence, the content of magnesium oxide is 83.88%, and the removal rate of potassium chloride is 99.597%.

[ example 4 ]

Step (1) same as example 1;

(2) preparing a composite acid solution from 0.05-1mol/L nitric acid (0.25mol/L nitric acid 2kg) and 0.05-1mol/L organic acid (0.5mol/L citric acid 9kg) at room temperature according to a mass ratio of 1: 4.5;

(3) uniformly mixing the powder obtained in the step (1) with the composite acid solution prepared in the step (2) according to the mass ratio of 1:4.4 (2.5 kg of powder and 11kg of composite acid solution), and soaking for 24 hours at 25 ℃ to obtain a mixed solution;

(4) and (4) removing supernatant of the mixed solution obtained in the step (3), repeatedly washing and filtering the precipitate for 3 times (20kg of water) by using tap water, and drying the filtered precipitate in a drying kiln or an oven at 110 ℃ for 24 hours to obtain the regenerated complex-phase magnesia fine powder.

The X-ray fluorescence is adopted to detect that the potassium chloride content in the sample is 0.005%, the magnesium oxide content is 85.62% and the potassium chloride removal rate is 99.856%.

[ example 5 ]

Step (1) same as example 1;

(2) preparing a composite acid solution from 0.05-1mol/L nitric acid (0.1mol/L nitric acid 2kg) and 0.05-1mol/L organic acid (1mol/L citric acid 3kg) at room temperature according to a mass ratio of 1: 1.5;

(3) uniformly mixing the powder obtained in the step (1) with the composite acid solution prepared in the step (2) according to the mass ratio of 1:2 (2.5 kg of powder and 5kg of composite acid solution), and soaking at 25 ℃ for 12 hours to obtain a mixed solution;

(4) and (4) removing supernatant of the mixed solution obtained in the step (3), repeatedly washing and filtering the precipitate for 3 times (10kg of water) by using tap water, and drying the filtered precipitate in a drying kiln or an oven at 110 ℃ for 24 hours to obtain the regenerated complex-phase magnesia fine powder.

The content of potassium chloride in the sample is detected to be 0.014%, the content of magnesium oxide is detected to be 84.12% and the removal rate of potassium chloride is detected to be 99.597% by adopting X-ray fluorescence.

[ example 6 ]

Step (1) same as example 1;

(2) preparing a composite acid solution from 0.05-1mol/L nitric acid (0.5mol/L nitric acid 1kg) and 0.05-1mol/L organic acid (1mol/L citric acid 3kg and 0.5mol/L malic acid 1kg) at room temperature according to the mass ratio of 1: 4;

(3) uniformly mixing the powder obtained in the step (1) with the composite acid solution prepared in the step (2) according to the mass ratio of 1:2 (2.5 kg of powder and 5kg of composite acid solution), and soaking at 25 ℃ for 24 hours to obtain a mixed solution;

(4) and (4) removing supernatant of the mixed solution obtained in the step (3), repeatedly washing and filtering the precipitate for 3 times (10kg of water) by using tap water, and drying the filtered precipitate in a drying kiln or an oven at 200 ℃ for 24 hours to obtain the regenerated complex-phase magnesia fine powder.

The X-ray fluorescence detection is adopted to detect that the potassium chloride content in the sample is 0.019%, the magnesium oxide content is 85.73%, and the potassium chloride removal rate is 99.452%.

Comparative example 1

Step (1) same as example 1;

(2) uniformly mixing the powder obtained in the step (1) with tap water according to the mass ratio of 1:2 (2.5 kg of powder and 5kg of tap water), and soaking for 24 hours at 25 ℃ to obtain a mixed solution;

(4) and (3) removing supernatant of the mixed solution obtained in the step (2), repeatedly washing and filtering the precipitate for 3 times (15kg of water) by using tap water, and drying the filtered precipitate in a drying kiln or an oven at 110 ℃ for 12h to obtain the regenerated complex-phase magnesia fine powder.

Comparative example 1 implementation procedure in comparison with example 1, the procedure for preparing the complex acid solution was omitted and tap water was used instead of the complex acid solution.

The X-ray fluorescence detection is adopted to detect that the potassium chloride content in the sample is 0.350%, the magnesium oxide content is 82.55%, and the potassium chloride removal rate is 89.914%.

Comparative example 2

Step (1) same as example 1;

(2) preparing a composite acid solution from 0.05-1mol/L nitric acid (0.05mol/L nitric acid 2kg) and 0.01mol/L organic acid (0.01mol/L citric acid 3kg) at room temperature according to the mass ratio of 1: 1.5;

(3) uniformly mixing the powder obtained in the step (1) with the composite acid solution prepared in the step (2) according to the mass ratio of 1:2 (2.5 kg of powder and 5kg of composite acid solution), and soaking for 24 hours at 25 ℃ to obtain a mixed solution;

(4) and (4) removing supernatant of the mixed solution obtained in the step (3), repeatedly washing and filtering the precipitate for 3 times (15kg of water) by using tap water, and drying the filtered precipitate in a drying kiln or an oven at 110 ℃ for 12h to obtain the regenerated complex-phase magnesia fine powder.

Comparative example 2 the procedure was carried out as in example 1 except that 0.01mol/L citric acid was used instead of 0.15mol/L citric acid in step (2).

The X-ray fluorescence detection is adopted to detect that the potassium chloride content in the sample is 0.147%, the magnesium oxide content is 83.79%, and the potassium chloride removal rate is 95.764%.

Comparative example 3

Step (1) same as example 1;

(2) uniformly mixing the powder obtained in the step (1) with 0.15mol/L citric acid according to the mass ratio of 1:2 (2.5 kg of powder and 5kg of citric acid), and soaking for 24 hours at 25 ℃ to obtain a mixed solution;

(3) and (3) removing supernatant of the mixed solution obtained in the step (2), repeatedly washing and filtering the precipitate for 3 times (15kg of water) by using tap water, and drying the filtered precipitate in a drying kiln or an oven at 110 ℃ for 12h to obtain the regenerated complex-phase magnesia fine powder.

Comparative example 3 implementation procedure in comparison with example 1, the procedure for preparing the complex acid solution was omitted and 5kg of 0.15mol/L citric acid was used instead of the complex acid solution.

The content of potassium chloride in the sample is detected to be 0.031%, the content of magnesium oxide is 84.57% and the removal rate of potassium chloride is 99.107% by adopting X-ray fluorescence.

Comparative example 4

Step (1) same as example 1;

(2) preparing a composite acid solution from 0.05-1mol/L nitric acid (0.05mol/L nitric acid 2kg) and 0.05-1mol/L organic acid (0.15mol/L citric acid 3kg) at room temperature according to the mass ratio of 1: 1.5;

(3) uniformly mixing the powder obtained in the step (1) with the composite acid solution prepared in the step (2) according to the mass ratio of 1:0.5 (2.5 kg of powder and 1.25kg of composite acid solution), and soaking at 25 ℃ for 24 hours to obtain a mixed solution;

(4) and (4) removing supernatant of the mixed solution obtained in the step (3), repeatedly washing and filtering the precipitate for 3 times (15kg of water) by using tap water, and drying the filtered precipitate in a drying kiln or an oven at 110 ℃ for 12h to obtain the regenerated complex-phase magnesia fine powder.

Comparative example 4 the procedure was carried out as in example 1 except that the mass ratio of the powder material in step (3) to the composite acid solution was 1: 0.5.

The X-ray fluorescence detection is adopted to detect that the potassium chloride content in the sample is 0.069%, the magnesium oxide content is 84.13%, and the potassium chloride removal rate is 98.012%.

TABLE 1 Potassium chloride removal

As can be seen from Table 1, the specific embodiment of the invention has the highest removal rate of the potassium chloride in the bricks used in the cement kiln of 99.856 percent and the residual potassium chloride of only 0.005 percent, which is superior to the index that the chloride in the national standard GB/T17431.1-2010 light aggregate and the test method part 1 of the light aggregate is less than or equal to 0.02 percent, and the obtained complex phase magnesium oxide powder can be used as a preparation raw material of a refractory material, thereby effectively solving the problem that the bricks used in the cement kiln are piled up to pollute the environment and producing obvious economic and social benefits.

The above description is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any idea or transformation proposed by those skilled in the art within the technical scope of the present invention is within the scope of the present invention.