阅读说明：本技术 一种改性磷酸钾镁水泥 (Modified magnesium potassium phosphate cement ) 是由 任骏 许圣业 杜冠宏 祝海燕 周波 于 2020-12-29 设计创作，主要内容包括：本发明涉及建筑材料领域,具体涉及一种改性磷酸钾镁水泥。以所述改性磷酸钾镁水泥的总质量计,改性磷酸钾镁水泥包括以下重量份的原料：重烧氧化镁100份、轻烧氧化镁10-50份、磷酸钾盐20-100份、磷石膏10-100份、缓凝剂1-50份以及减水剂0-5份。通过以重烧氧化镁、磷酸钾盐、缓凝剂为主要组分,再掺加大量的磷石膏和轻烧氧化镁,从而可以解决磷酸钾镁水泥凝结快的缺点,同时本发明提供的改性磷酸钾镁水泥还具有强度高且稳定、成本低、经济效益和社会效益高的优点。(The invention relates to the field of building materials, in particular to modified magnesium potassium phosphate cement. The modified magnesium potassium phosphate cement comprises the following raw materials in parts by weight: 100 parts of heavy-burned magnesia, 10-50 parts of light-burned magnesia, 20-100 parts of potassium phosphate, 10-100 parts of phosphogypsum, 1-50 parts of retarder and 0-5 parts of water reducing agent. The modified magnesium potassium phosphate cement provided by the invention also has the advantages of high and stable strength, low cost, high economic benefit and high social benefit.)

1. The modified magnesium potassium phosphate cement is characterized by comprising the following raw materials in parts by weight:

100 parts of heavy-burned magnesia, 10-50 parts of light-burned magnesia, 20-100 parts of potassium phosphate, 10-100 parts of phosphogypsum, 1-50 parts of retarder and 0-5 parts of water reducing agent.

2. The modified magnesium potassium phosphate cement of claim 1, wherein the dead burned magnesia is formed by calcining magnesite at a temperature above 1500 ℃.

3. The modified magnesium potassium phosphate cement of claim 1 or 2, wherein the phosphate comprises at least one of potassium dihydrogen phosphate and potassium dihydrogen phosphate.

4. The modified magnesium potassium phosphate cement according to any of claims 1-3, wherein the phosphogypsum has a calcium sulphate content of not less than 80%, and a specific surface area of 200-350m²/kg。

5. The modified magnesium potassium phosphate cement of any one of claims 1-4, wherein the set retarder comprises at least one of borax, boric acid, and sodium polyphosphate.

6. The modified magnesium potassium phosphate cement of any one of claims 1-5, wherein the water reducer is a liquid polycarboxylic acid-based high performance water reducer.

7. The modified magnesium potassium phosphate cement of any one of claims 1-6, wherein the light-burned magnesium oxide is obtained by calcining siderite at 900 ℃ of 700-.

Technical Field

The invention relates to the field of building materials, in particular to modified magnesium potassium phosphate cement.

Background

As a new type of inorganic cementitious material, magnesium phosphate cement can be made to react with water to give a crystalline material with high strength, and is therefore also referred to as "chemically bonded magnesium phosphate ceramic". The magnesium phosphate cement has unique and specific properties of quick condensation, high early strength, small shrinkage, good adhesion, high temperature resistance, freeze-thaw resistance, simple maintenance and the like, so the magnesium phosphate cement is widely applied to the fields of reinforcing and repairing concrete structures, sealing treatment of harmful and radioactive wastes and the like.

The traditional magnesium phosphate cement mainly takes magnesium oxide and diamine phosphate as raw materials, the acid-base neutralization reaction between the magnesium oxide and the diamine phosphate is rapid and can emit a large amount of heat, and the released heat energy can further accelerate the reaction, so the magnesium phosphate cement can be coagulated in a short time, and the material formed by cementing the reaction product has higher strength. However, because a large amount of ammonia gas overflows from the monoammonium phosphate after the reaction, which affects the environment, at present, more scholars propose to obtain magnesium potassium phosphate cement with performance similar to that of the traditional magnesium phosphate cement by using monopotassium phosphate to replace the ammonium dihydrogen phosphate.

Although the magnesium potassium phosphate cement solves the problem of ammonia gas overflow, the magnesium potassium phosphate cement has the defect of excessively high condensation speed, so that the application of the magnesium potassium phosphate cement in the engineering field is limited.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to overcome the defect that the setting speed of the magnesium potassium phosphate cement in the prior art is too high, thereby providing the modified magnesium potassium phosphate cement and the use method thereof.

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

the modified magnesium potassium phosphate cement comprises the following raw materials in parts by weight:

100 parts of heavy-burned magnesia, 10-50 parts of light-burned magnesia, 20-100 parts of potassium phosphate, 10-100 parts of phosphogypsum, 1-50 parts of retarder and 0-5 parts of water reducing agent.

Optionally, the dead burned magnesia is formed by calcining magnesite at a temperature of more than 1500 ℃.

Optionally, the potassium phosphate salt comprises at least one of potassium dihydrogen phosphate and potassium dihydrogen phosphate.

Optionally, in the phosphogypsum, the content of calcium sulfate is not less than 80%, and the specific surface area of the phosphogypsum is 200-350m²/kg。

Optionally, the retarder includes at least one of borax, boric acid, and sodium polyphosphate.

Optionally, the water reducing agent is a liquid polycarboxylic acid high-performance water reducing agent.

Optionally, the light-burned magnesium oxide is obtained by calcining siderite at the temperature of 700-900 ℃.

The technical scheme of the invention has the following advantages:

1. the modified potassium magnesium phosphate cement provided by the invention takes the dead burned magnesium oxide, the potassium phosphate and the retarder as main components, and is doped with a large amount of phosphogypsum, so that the defect of fast setting of the potassium magnesium phosphate cement can be solved, and meanwhile, the modified potassium magnesium phosphate cement provided by the invention also has the advantages of high and stable strength, low cost and high economic and social benefits.

Detailed Description

The following examples are provided to further understand the present invention, not to limit the scope of the present invention, but to provide the best mode, not to limit the content and the protection scope of the present invention, and any product similar or similar to the present invention, which is obtained by combining the present invention with other prior art features, falls within the protection scope of the present invention.

The examples do not show the specific experimental steps or conditions, and can be performed according to the conventional experimental steps described in the literature in the field. The reagents or instruments used are not indicated by manufacturers, and are all conventional reagent products which can be obtained commercially. The phosphogypsum used in the examples is purchased from Yunnan phosphate fertilizer plants.

Example 1

The embodiment relates to modified potassium magnesium phosphate cement, which comprises 100g of dead-burned magnesia, 10g of light-burned magnesia, 25g of monopotassium phosphate, 25g of phosphogypsum and 15g of borax.

Example 2

The embodiment relates to modified potassium magnesium phosphate cement, which comprises 100g of dead-burned magnesia, 50g of light-burned magnesia, 100g of potassium monohydrogen phosphate, 60g of phosphogypsum and 30g of boric acid.

Example 3

The embodiment relates to modified potassium magnesium phosphate cement, which comprises 100g of dead burned magnesium oxide, 30g of light burned magnesium oxide, 25g of potassium hydrogen phosphate, 60g of phosphogypsum, 20g of sodium polyphosphate and 2g of water reducing agent.

Example 4

The embodiment relates to modified potassium magnesium phosphate cement, which comprises 100g of dead burned magnesia, 10g of light burned magnesia, 100g of monopotassium phosphate, 40g of phosphogypsum, 10g of borax and 2g of water reducing agent.

Example 5

The embodiment relates to modified potassium magnesium phosphate cement, which comprises 100g of dead-burned magnesia, 10g of light-burned magnesia, 100g of monopotassium phosphate, 40g of phosphogypsum and 10g of borax.

Comparative example 1

The embodiment relates to magnesium phosphate cement which comprises 100g of dead-burned magnesium oxide, 25g of monopotassium phosphate and 16g of borax.

Test examples

The modified potassium magnesium phosphate cements provided in examples 1 to 4 and comparative example 1 were mixed and tested for setting properties as follows.

Mixing:

1) firstly, weighing heavy-burned magnesium oxide, (light-burned magnesium oxide), monopotassium phosphate, phosphogypsum and borax respectively according to the proportion;

2) putting the weighed solid into a stirrer to mix solid components;

3) weighing water according to the water-solid ratio of 0.50, weighing a water reducing agent according to the proportion, mixing the water and the water reducing agent, and adding the mixture into a stirring pot;

4) then adding the solid component prepared in the step 2) into a stirring pot, stirring at a low speed for 30 seconds, and then stirring at a high speed for 60 seconds;

5) pouring the slurry into a mold for molding immediately after the stirring is finished;

6) the mould was placed on a vibrating table and vibrated 60 times to remove air bubbles and then trowelled with a cement spatula.

The results of the performance tests are shown in Table 1.

TABLE 1 Performance test results of cements of examples and comparative examples

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.