阅读说明：本技术 一种高岭土基结合剂及其制备方法和应用 (Kaolin-based binder and preparation method and application thereof ) 是由 刘永 王红强 罗明亮 李向阳 王清良 李衡宇 于 2021-09-07 设计创作，主要内容包括：本发明属于无机粘结剂技术领域,提供了一种高岭土基结合剂,制备所述高岭土基结合剂的原料包括高岭土和磷酸,所述高岭土和磷酸的质量比为100：(50～300)。本发明以高岭土为原料,以磷酸为粘结剂,制备高岭土基结合剂；高岭土是一种以高岭石族粘土矿物为主的粘土和粘土岩,来源广泛,成本低,并且具有较强的耐酸性能；高岭土可与磷酸发生化学反应,通过控制磷酸与高岭土的质量比,生成粘结性能较强的磷酸二氢铝、磷酸一氢铝和硅胶。实施例的结果显示,本发明提供的高岭土基结合剂与石英砂和氧化镁制成的产品的抗压强度为11.59MPa。(The invention belongs to the technical field of inorganic binders, and provides a kaolin-based binder, wherein raw materials for preparing the kaolin-based binder comprise kaolin and phosphoric acid, and the mass ratio of the kaolin to the phosphoric acid is 100: (50-300). The invention takes kaolin as raw material and phosphoric acid as binder to prepare kaolin-based binder; the kaolin is clay and claystone which mainly uses kaolinite clay minerals, has wide sources, low cost and stronger acid resistance; the kaolin can react with phosphoric acid chemically, and aluminum dihydrogen phosphate, aluminum monohydrogen phosphate and silica gel with strong bonding property are generated by controlling the mass ratio of the phosphoric acid to the kaolin. The results of the examples show that the compressive strength of the product made of the kaolin-based binder provided by the present invention, quartz sand and magnesium oxide is 11.59 MPa.)

1. The kaolin-based binder is prepared from kaolin and phosphoric acid, wherein the mass ratio of the kaolin to the phosphoric acid is 100: (50-300).

2. The kaolin-based binder according to claim 1, wherein the mass ratio of kaolin to phosphoric acid is 100: (50-180).

3. The kaolin-based binder of claim 1, wherein the kaolin comprises one or more of raw kaolin clay, concentrate kaolin clay, metakaolin, and calcined kaolin.

4. The kaolin-based binder according to claim 1, wherein the phosphoric acid is added in the form of an aqueous phosphoric acid solution; the mass concentration of the phosphoric acid aqueous solution is 60-80%.

5. A method for preparing the kaolin-based binder of any one of claims 1 to 4, comprising the steps of:

mixing phosphoric acid and kaolin for molding to obtain green balls;

carrying out heat seal on the green ball to obtain a cooked ball;

and crushing the cooked ball to obtain the kaolin-based binder.

6. The method according to claim 5, wherein the sealing temperature is 50 to 200 ℃; the heat sealing time is 30-180 min.

7. The method according to claim 5 or 6, further comprising, after said pulverizing:

mixing the powder obtained by crushing with phosphoric acid and forming to obtain a secondary ball;

carrying out second heat seal on the secondary balls to obtain secondary cooked balls;

and crushing the secondary cooked ball to obtain the kaolin-based binder.

8. The method according to claim 7, wherein the mass ratio of the powder to the phosphoric acid is 100: (60-180).

9. The method of claim 7, wherein the temperature of the second heat seal is 500 to 1000 ℃; and the time of the second heat seal is 30-180 min.

10. Use of the kaolin-based binder according to any one of claims 1 to 4 or the kaolin-based binder prepared by the preparation method according to any one of claims 5 to 9 in the preparation of inorganic waste solidified bodies and water glass solidified bodies.

Technical Field

The invention relates to the technical field of inorganic binders, in particular to a kaolin-based binder and a preparation method and application thereof.

Background

The phosphate binder is a building cementing material, has plasticity before setting and hardening, and can be made into products with any size and shape according to requirements; can be solidified at normal temperature and sintered at high temperature; can be used in combination with dispersant, curing agent, aggregate, etc. to make products similar to concrete. In addition, the phosphate binder has the advantages of high strength, high hardness, good water resistance, small curing shrinkage, environmental protection, no toxicity, good construction performance and strong adaptability to materials, and is further widely applied to industrial and civil fields of refractory materials, building materials, metal casting, inorganic coatings, composite materials and the like.

Common phosphate binders include aluminum dihydrogen phosphate and silicon phosphate, but in the prior art, high-quality aluminum oxide or aluminum hydroxide is usually used for preparing aluminum dihydrogen phosphate, so that the cost is high, and the application and popularization of the aluminum dihydrogen phosphate are limited; in the prior art, the silicon phosphate is prepared by taking quartz as a basic raw material and synthesizing at a high temperature (700-1000 ℃), so that the manufacturing cost is high. Therefore, there is a need to solve the problem of high manufacturing cost of the existing phosphate-based binders to achieve a wide range of applications of phosphate binders.

Disclosure of Invention

The invention aims to provide a kaolin-based binder, a preparation method and application thereof.

In order to achieve the above purpose, the invention provides the following technical scheme:

the invention provides a kaolin-based binder, which is prepared from the following raw materials in a mass ratio of 100: (50-300).

Preferably, the mass ratio of the kaolin to the phosphoric acid is 100: (50-180).

Preferably, the kaolin comprises one or more of raw kaolin ore, kaolin concentrate, metakaolin and calcined kaolin.

Preferably, the phosphoric acid is added in the form of an aqueous phosphoric acid solution; the mass concentration of the phosphoric acid aqueous solution is 60-80%.

The invention also provides a preparation method of the kaolin-based bonding agent in the technical scheme, which comprises the following steps:

mixing phosphoric acid and kaolin for molding to obtain green balls;

carrying out heat seal on the green ball to obtain a cooked ball;

and crushing the cooked ball to obtain the kaolin-based binder.

Preferably, the temperature of the heat seal is 50-200 ℃; the heat sealing time is 30-180 min.

Preferably, the method further comprises the following steps after the crushing:

mixing the powder obtained by crushing with phosphoric acid and forming to obtain a secondary ball;

carrying out second heat seal on the secondary balls to obtain secondary cooked balls;

and crushing the secondary cooked ball to obtain the kaolin-based binder.

Preferably, the mass ratio of the powder to the phosphoric acid is 100: (60-180).

Preferably, the temperature of the second heat seal is 500-1000 ℃; and the time of the second heat seal is 30-180 min.

The invention also provides the application of the kaolin-based binder or the kaolin-based binder prepared by the preparation method in the technical scheme in the preparation of inorganic waste solidified bodies and water glass solidified bodies.

The invention provides a kaolin-based binder, which is prepared from the following raw materials in a mass ratio of 100: (50-300). The invention takes kaolin as raw material and phosphoric acid as binder to prepare kaolin-based binder; the kaolin is clay and claystone which mainly uses kaolinite clay minerals, has wide sources, low cost and stronger acid resistance; the kaolin can react with phosphoric acid chemically, and aluminum dihydrogen phosphate, aluminum monohydrogen phosphate and silica gel with strong bonding property are generated by controlling the mass ratio of the phosphoric acid to the kaolin. The results of the examples show that the compressive strength of the product made of the kaolin-based binder provided by the present invention, quartz sand and magnesium oxide is 11.59 MPa.

The preparation method of the kaolin-based binder provided by the invention is simple to operate and mild in reaction conditions.

Detailed Description

The invention provides a kaolin-based binder, which is prepared from the following raw materials in a mass ratio of 100: (50-300).

In the present invention, the raw materials for preparing the kaolin-based binder include kaolin and phosphoric acid. The invention takes kaolin as raw material and phosphoric acid as binder to prepare kaolin-based binder; the kaolin is clay and claystone which mainly uses kaolinite clay minerals, has wide sources, low cost and stronger acid resistance; kaolin can react with phosphoric acid to produce aluminium dihydrogen phosphate, aluminium monohydrogen phosphate and silica gel with strong binding property.

In the invention, the mass ratio of the kaolin to the phosphoric acid is 100: (50-300), preferably 100: (50-180). The invention can generate aluminum dihydrogen phosphate, aluminum monohydrogen phosphate and silica gel with stronger bonding property by controlling the mass ratio of the phosphoric acid to the kaolin.

In the present invention, the kaolin preferably comprises one or more of raw kaolin ore, kaolin concentrate, metakaolin and calcined kaolin, more preferably kaolin concentrate or metakaolin. The kaolin is not particularly limited in its origin and may be obtained from commercially available products known to those skilled in the art.

In the present invention, Al in the kaolin is₂O₃The grade of the product is preferably ≧ 35%; the particle size of the kaolin is preferably-0.074 mm and ≧ 95%; the kaolin is preferably in the form of a powder.

In the present invention, the phosphoric acid is preferably added in the form of an aqueous phosphoric acid solution; the phosphoric acid aqueous solution preferably has a mass concentration of 60 to 80%, more preferably 72 to 76%.

The invention takes kaolin as raw material and phosphoric acid as binder to prepare kaolin-based binder; the kaolin can react with phosphoric acid chemically, and aluminum dihydrogen phosphate, aluminum monohydrogen phosphate and silica gel with strong bonding property are generated by controlling the mass ratio of the phosphoric acid to the kaolin.

The invention also provides a preparation method of the kaolin-based bonding agent in the technical scheme, which comprises the following steps:

mixing phosphoric acid and kaolin for molding to obtain green balls;

carrying out heat seal on the green ball to obtain a cooked ball;

and crushing the cooked ball to obtain the kaolin-based binder.

The invention mixes and shapes phosphoric acid and kaolin to obtain the green ball.

In the present invention, the phosphoric acid is preferably heated before use. According to the invention, phosphoric acid is heated, so that the phosphoric acid is easy to flow, and the kaolin and the phosphoric acid are favorably and uniformly mixed. In the invention, the heating temperature is preferably 45-90 ℃, and more preferably 45-70 ℃.

The method for mixing and molding the phosphoric acid and the kaolin is not particularly limited, and the molding method known to those skilled in the art can be adopted. In the present invention, the forming equipment is preferably a double-roll pelletizer, a disk pelletizer or a rotary drum pelletizer, more preferably a rotary drum pelletizer.

In the invention, the diameter of the green ball is preferably 5-30 mm, and more preferably 15-30 mm.

After the green ball is obtained, the green ball is subjected to heat sealing to obtain a cooked ball. The invention makes phosphoric acid and kaolin react by heat seal, thereby generating a substance with stronger bonding property.

In the invention, the heat sealing temperature is preferably 50-200 ℃, and more preferably 100-150 ℃; the heat sealing time is preferably 30-180 min, and more preferably 60-120 min. In the present invention, the heating means of the heat seal is preferably direct heating or indirect heating; the equipment used for heat sealing is preferably an oven.

In the present invention, the following chemical reactions occur between phosphoric acid and kaolin during the sealing process:

H₃PO₄+2SiO₂·Al₂O₃·2H₂O→Al(H₂PO₄)₃+SiO₂·nH₂O

H₃PO₄+2SiO₂·Al₂O₃·2H₂O→Al₂(HPO₄)₃+SiO₂·nH₂O

H₃PO₄+2SiO₂·Al₂O₃·2H₂O→AlPO₄+SiO₂·nH₂O

after obtaining the cooked ball, the invention crushes the cooked ball to obtain the kaolin-based binder. The invention prepares the cooked ball into kaolin-based bonding agent powder by crushing, and is convenient to use.

In the present invention, the pulverization is preferably carried out by grinding; the grinding mode is preferably ball milling; the equipment used for ball milling is preferably a ball mill.

In the present invention, the particle size of the kaolin-based binder obtained after pulverization is preferably-0.074 mm, ≧ 50%, more preferably-0.074 mm, > 95%.

In the present invention, after the pulverization, it is preferable to further include:

mixing the powder obtained by crushing with phosphoric acid and forming to obtain a secondary ball;

carrying out second heat seal on the secondary balls to obtain secondary cooked balls;

and crushing the secondary cooked ball to obtain the kaolin-based binder.

The invention preferably mixes the powder obtained by crushing with phosphoric acid for molding to obtain the secondary ball.

In the present invention, the mass ratio of the powder to phosphoric acid is preferably 100: (60 to 180), more preferably 100: (80-150). In the invention, silicon phosphate with different compositions can be obtained by adjusting the mass ratio of the phosphoric acid to the powder.

In the invention, the mixing and molding mode of the secondary balls is the same as that of the green balls, and the description is omitted.

After the secondary balls are obtained, the invention preferably carries out second heat sealing on the secondary balls to obtain secondary cooked balls. In the invention, the temperature of the second heat seal is preferably 500-1000 ℃, and more preferably 700-800 ℃; the second heat sealing time is preferably 30-180 min, and more preferably 60-120 min.

In the invention, the following chemical reactions occur between the powder and the phosphoric acid in the secondary heat sealing process:

H₃PO₄+SiO₂→3SiO₂·2P₂O₅+H₂O

H₃PO₄+SiO₂→SiO₂·P₂O₅+H₂O

in the present invention, the particle size of the kaolin-based binder obtained after pulverization is preferably-0.074 mm, ≧ 75%, more preferably-0.074 mm, > 95%.

The invention preferably uses secondary heat seal to react phosphoric acid and silicon dioxide in the powder to generate silicon phosphate, thereby further improving the bonding property of the kaolin-based bonding agent.

According to the invention, the kaolin-based binder can be obtained by sequentially mixing, molding, heat-sealing and crushing kaolin and phosphoric acid, and the preparation method is simple to operate and mild in reaction conditions.

The invention also provides the application of the kaolin-based binder or the kaolin-based binder prepared by the preparation method in the technical scheme in the preparation of inorganic solid waste solidified bodies and water glass solidified bodies.

According to the invention, the kaolin-based binder is used for preparing the inorganic waste solidified body, so that the inorganic waste is effectively treated, and the solidified body with high strength is obtained.

In the present invention, the method for producing the inorganic waste solidified body is preferably: mixing the kaolin-based binder and the inorganic waste, adding water, casting and standing for 2 days to obtain an inorganic waste solidified body. In the present invention, the inorganic waste preferably includes one or more of ceramic plate, refractory brick, quartz sand, corundum powder, graphite and stone.

In the present invention, the raw materials for preparing the inorganic waste solidified body preferably further include one or more of a blending material, a dispersing agent, a curing agent and a reinforcing agent. In the present invention, the admixture, the dispersant, the curing agent and the reinforcing agent are preferably added while the kaolin-based binder is mixed with the inorganic waste.

In the present invention, the admixture preferably comprises fly ash and/or blast furnace slag; the dispersant preferably comprises phosphate and/or sodium polyacrylate; the curing agent preferably comprises copper oxide and/or magnesium oxide; the reinforcing agent preferably comprises SiO₂And/or alpha-Al₂O₃。

According to the invention, the kaolin-based binder is used for preparing the water glass solidified body, and the obtained water glass solidified body has higher strength.

In the present invention, the method for producing the water glass cured body is preferably: adding water into the solid waste, the admixture, the stabilizer, the water glass and the kaolin-based binder, uniformly stirring, then casting and molding, and standing for 2 days to obtain the water glass solidified body.

In the present invention, the water glass solidified body is preferably used for treating industrial solid waste or nuclear industrial waste liquid; the industrial solid waste preferably comprises mineral processing tailings, barium chemical slag or metallurgical waste slag; the nuclear industry waste stream is preferably a waste stream containing resins, borates or oleochemicals.

The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

Uniformly mixing 600g of phosphoric acid and 200g of powdery kaolin (the mass ratio of the kaolin to the phosphoric acid is 100:300), preparing raw balls with the diameter of 15-30 mm by using a rotary drum granulator, placing the raw balls in an oven, heating to 145 ℃, and preserving heat for 150min to obtain cooked balls; and ball-milling the cooled cooked balls to-0.074 mm, wherein the mass of the cooled cooked balls is not less than 95%, and the cooled cooked balls are the kaolin-based bonding agent.

Application example 1

200g of quartz sand, 40g of the kaolin-based binder prepared in example 1 and 6g of magnesium oxide were mixed and pulverized, 36.9mL of deionized water was added, the mixture was stirred uniformly and allowed to stand for 2 days to obtain a solidified body, the weight loss rate of the solidified body was measured to be 0.93%, and the compressive strength was 11.59 MPa.

Application example 2

200g of quartz sand, 40g of the kaolin-based binder prepared in example 1 and 6g of magnesium oxide are mixed and crushed, 36.9mL of deionized water is added, the mixture is stirred uniformly, the mixture is placed in a constant-temperature drying oven at 165 ℃ after being kept stand for 2 days for heat preservation for 2 hours, a solidified body is obtained, the weight loss rate of the solidified body is 14.30%, and the compressive strength is 12.58 MPa.

Application example 3

200g of quartz sand, 50g of the kaolin-based binder prepared in example 1, 7.5g of magnesium oxide and 10.2g of waste uranium-containing rocks are mixed and crushed, 32.1mL of deionized water is added, the mixture is stirred uniformly, the mixture is placed in a constant-temperature drying oven at 175 ℃ after being kept stand for 2 days, heat preservation is carried out for 2 hours, a solidified body is obtained, and the weight loss rate of the solidified body is measured to be 17.06%. And (3) crushing the solidified body to-200 meshes, soaking the solidified body in distilled water for 6 days to obtain the uranium leaching rate of 0.68%, and continuously soaking the solidified body for 2 days without increasing the uranium leaching rate.

Example 2

Uniformly mixing 400g of phosphoric acid and 200g of powdery kaolin (the mass ratio of the kaolin to the phosphoric acid is 100:200), preparing raw balls with the diameter of 15-30 mm by using a rotary drum granulator, placing the raw balls in an oven, heating to 145 ℃, and preserving heat for 150min to obtain cooked balls; and ball-milling the cooled cooked balls to-0.074 mm, wherein the mass of the cooled cooked balls is not less than 95%, and the cooled cooked balls are the kaolin-based bonding agent.

Application example 4

200g of quartz sand, 40g of the kaolin-based binder prepared in example 2 and 6g of magnesium oxide were mixed and pulverized, 36.9mL of deionized water was added, the mixture was stirred uniformly and allowed to stand for 2 days to obtain a solidified body, and the weight loss rate of the solidified body was measured to be 3.3%.

Example 3

Uniformly mixing 200g of phosphoric acid and 200g of powdery kaolin (the mass ratio of the kaolin to the phosphoric acid is 100:100), preparing raw balls with the diameter of 15-30 mm by using a rotary drum granulator, placing the raw balls in an oven, heating to 145 ℃, and preserving heat for 150min to obtain cooked balls; and ball-milling the cooled cooked balls to-0.074 mm, wherein the mass of the cooled cooked balls is not less than 95%, and the cooled cooked balls are the kaolin-based bonding agent.

Application example 5

200g of quartz sand, 40g of the kaolin-based binder prepared in example 3 and 6g of magnesium oxide were mixed and pulverized, 36.9mL of deionized water was added, the mixture was stirred uniformly and allowed to stand for 2 days to obtain a solidified body, and the weight loss rate of the solidified body was measured to be 13.37%.

Example 4

Uniformly mixing 600g of phosphoric acid and 200g of powdery kaolin (the mass ratio of the kaolin to the phosphoric acid is 100:300), preparing raw balls with the diameter of 15-30 mm by using a rotary drum granulator, placing the raw balls in an oven, heating to 145 ℃, and preserving heat for 150min to obtain cooked balls; ball-milling the cooled cooked balls into powder with a particle size of-0.074 mm and a particle size of 95% or more;

uniformly mixing the powder with 480g of phosphoric acid (the mass ratio of the powder to the phosphoric acid is 100:60), preparing a secondary ball with the diameter of 15-30 mm by using a rotary drum granulator, placing the secondary ball in an oven, heating to 800 ℃, and preserving heat for 120min to obtain a secondary cooked ball; and (3) ball-milling the cooled secondary cooked balls to-0.074 mm, wherein not less than 95% of powder is the kaolin-based bonding agent.

Application example 6

200g of quartz sand, 40g of the kaolin-based binder prepared in example 4 and 6g of magnesium oxide were mixed and pulverized, and then 36.9mL of deionized water was added thereto, followed by stirring and standing for 2 days to obtain a solidified body.

The above examples show that the kaolin-based bonding agent provided by the invention has low manufacturing cost and good bonding property, and the compressive strength of the product prepared from the kaolin-based bonding agent, quartz sand and magnesium oxide is 11.59 MPa.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.