阅读说明：本技术 氯氧镁水泥基渣土免烧建筑材料及其制备方法 (Magnesium oxychloride cement-based muck non-fired building material and preparation method thereof ) 是由 张水 李水生 阳栋 于 2021-09-07 设计创作，主要内容包括：本发明公开了一种氯氧镁水泥基渣土免烧建筑材料及其制备方法,包括以下质量份的各组分：工程渣土以干重计80份～100份、轻烧氧化镁5份～30份、氯化镁1份～15份、工业废渣5份～20份、纤维0.2份～1.5份、改性剂0.1份～1.5份、激发剂0.5份～2份。本发明的氯氧镁水泥基渣土免烧建筑材料,以工程渣土为主要原材料,实现了渣土资源化利用。采用氯氧镁水泥与工业废渣协同固化工程渣土,得到的制品抗压强度高达60MPa,且具有较好的耐久性能；乱向分布的纤维具有增强效应,可提高氯氧镁水泥基制品的抗弯、抗拉强度,改善其韧性。改性剂可有效抑制氯氧镁水制品返卤。激发剂可激发工业废渣的活性,使其产生较好的固化作用。(The invention discloses a magnesium oxychloride cement-based muck non-fired building material and a preparation method thereof, wherein the magnesium oxychloride cement-based muck non-fired building material comprises the following components in parts by mass: the engineering slag soil comprises 80 to 100 portions of dry weight, 5 to 30 portions of light-burned magnesia, 1 to 15 portions of magnesium chloride, 5 to 20 portions of industrial waste residue, 0.2 to 1.5 portions of fiber, 0.1 to 1.5 portions of modifier and 0.5 to 2 portions of excitant. The magnesium oxychloride cement-based muck non-fired building material takes engineering muck as a main raw material, and realizes the resource utilization of the muck. The magnesium oxychloride cement and the industrial waste residue are used for cooperatively curing the engineering slag, so that the obtained product has the compressive strength of up to 60MPa and has better durability; the disorderly distributed fibers have a reinforcing effect, can improve the bending strength and the tensile strength of the magnesium oxychloride cement-based product, and improve the toughness of the magnesium oxychloride cement-based product. The modifier can effectively inhibit the halogen return of the magnesium oxychloride water product. The activator can excite the activity of the industrial waste residue to generate better curing effect.)

1. The magnesium oxychloride cement-based muck non-fired building material is characterized by comprising the following components in parts by mass:

the engineering slag soil comprises 80 to 100 portions of dry weight, 5 to 30 portions of light-burned magnesia, 1 to 15 portions of magnesium chloride, 5 to 20 portions of industrial waste residue, 0.2 to 1.5 portions of fiber, 0.1 to 1.5 portions of modifier and 0.5 to 2 portions of excitant.

2. The magnesium oxychloride cement-based muck non-fired building material as claimed in claim 1, wherein,

the engineering slag soil comprises 85 to 95 parts by dry weight, 8 to 25 parts by weight of light-burned magnesia, 2 to 9 parts by weight of magnesium chloride, 8 to 16 parts by weight of industrial waste residue, 0.2 to 1.0 part by weight of fiber, 0.3 to 1.0 part by weight of modifier and 0.5 to 1.5 parts by weight of excitant.

3. The magnesium oxychloride cement-based muck non-fired building material as claimed in claim 1 or 2, wherein,

the engineering muck is soil muck generated by foundation pit excavation or underground engineering construction; and/or the presence of a gas in the gas,

the water content of the engineering muck is lower than 3%.

4. The magnesium oxychloride cement-based muck non-fired building material as claimed in claim 1 or 2, wherein,

the industrial waste residue is one or more of mineral powder, fly ash or coal gangue powder; and/or the presence of a gas in the gas,

the fineness of the industrial waste residue is not less than 200 meshes.

5. The magnesium oxychloride cement-based muck non-fired building material as claimed in claim 1 or 2, wherein,

the fiber is at least one of crop straw fiber and polypropylene fiber; and/or the presence of a gas in the gas,

the length of the fibers does not exceed 20 mm.

6. The magnesium oxychloride cement-based muck non-fired building material as claimed in claim 1 or 2, wherein,

the modifier is one or more of phosphate, sulfate, phosphoric acid or silicon powder; and/or the presence of a gas in the gas,

the excitant is one or more of sodium hydroxide, sodium sulfate, sodium carbonate or sodium silicate.

7. A method for preparing the magnesium oxychloride cement-based muck unfired building material as claimed in any one of claims 1 to 6, comprising the steps of:

s1, adding magnesium chloride into water, and uniformly stirring to obtain a magnesium chloride aqueous solution;

s2, adding a modifier into the magnesium chloride aqueous solution obtained in the step S1, and uniformly stirring to obtain a mixture A;

s3, uniformly stirring the engineering slag soil, the light burned magnesium oxide, the industrial waste slag, the fiber and the exciting agent to obtain a mixture B;

s4, adding the mixture A obtained in the step S2 into the mixture B obtained in the step S3 in a spraying mode, and uniformly stirring to obtain a mixture C;

and S5, filling the mixture C obtained in the step S4 into a mold, adopting a pressure forming process, demolding, and curing to obtain the engineering muck-based baking-free building material.

8. The method for preparing the magnesium oxychloride cement-based muck unfired building material as claimed in claim 7, wherein the engineering muck is one crushed to have a particle size of less than 4.75 mm; and/or the Baume degree of the magnesium chloride aqueous solution is 22-30.

9. The method for preparing the magnesium oxychloride cement-based muck unfired building material as claimed in claim 7, wherein the water content of the mixture C is 6-18%; and/or the presence of a gas in the gas,

the molding pressure of the pressure molding process is 10 MPa-20 MPa.

10. The method for preparing the magnesium oxychloride cement-based muck unfired building material as claimed in claim 7, wherein the relative humidity of the curing is not less than 90%; and/or the presence of a gas in the gas,

the maintenance time is not less than 7 days.

Technical Field

The invention relates to the field of building materials, in particular to a magnesium oxychloride cement-based muck baking-free building material. In addition, the invention also relates to a preparation method of the magnesium oxychloride cement-based muck unfired building material.

Background

With the development of economy and the advancement of urbanization, construction waste continuously and rapidly increases. According to data statistics, about 18 hundred million t of construction wastes are generated every year, the resource utilization rate is less than 5 percent, and the current stock of construction wastes reaches more than 200 hundred million t. Among these construction wastes, the engineering waste has become the "prime force". At present, the main disposal method of engineering dregs is mainly to send to a receiving field for centralized landfill or stacking, and the situation of 'dregs enclosing city' is formed. The engineering dregs are buried or stacked in a centralized way, which not only occupies a large amount of land resources, pollutes the surrounding environment and has expensive disposal cost, but also has potential safety hazard.

The engineering slag soil is a mineral deposit in a city, is a resource misplaced place, and should be researched and utilized. At present, the utilization of engineering muck is concentrated on: separating sand and stone in the engineering muck, and preparing the sand through processes of washing, screening and the like; engineering residue soil is used as a main raw material, and building material products such as bricks, ceramsite and the like are manufactured by adopting a sintering process. However, the above method for resource utilization of engineering slag soil still has the problems of low utilization rate, high energy consumption and the like.

Disclosure of Invention

The invention provides a magnesium oxychloride cement-based muck non-fired building material and a preparation method thereof, and aims to solve the technical problems of low resource utilization rate of muck and high energy consumption of muck-based sintered products in the prior engineering.

The technical scheme adopted by the invention is as follows:

the magnesium oxychloride cement-based muck non-fired building material comprises the following components in parts by mass: the engineering slag soil comprises 80 to 100 portions of dry weight, 5 to 30 portions of light-burned magnesia, 1 to 15 portions of magnesium chloride, 5 to 20 portions of industrial waste residue, 0.2 to 1.5 portions of fiber, 0.1 to 1.5 portions of modifier and 0.5 to 2 portions of excitant.

Further, the engineering slag soil comprises 85 to 95 parts by dry weight of 85 to 25 parts by dry weight of light-burned magnesium oxide, 2 to 9 parts by dry weight of magnesium chloride, 8 to 16 parts by dry weight of industrial waste slag, 0.2 to 1.0 part by dry weight of fiber, 0.3 to 1.0 part by dry weight of modifier and 0.5 to 1.5 parts by dry weight of excitant.

Further, the engineering muck is soil-like muck generated by foundation pit excavation or underground engineering construction; and/or the water content of the engineering muck is lower than 3 percent.

Further, the industrial waste residue is one or more of mineral powder, fly ash or coal gangue powder; and/or the fineness of the industrial waste residue is not less than 200 meshes.

Furthermore, the fiber is at least one of crop straw fiber and polypropylene fiber; and/or the length of the fibres does not exceed 20 mm.

Further, the modifier adopts one or more of phosphate, sulfate, phosphoric acid or silicon powder.

Further, the exciting agent is one or more of sodium hydroxide, sodium sulfate, sodium carbonate or sodium silicate.

According to another aspect of the present invention, there is also provided a method for preparing the above magnesium oxychloride cement-based muck unfired building material, comprising the following steps:

s1, adding magnesium chloride into water, and uniformly stirring to obtain a magnesium chloride aqueous solution;

s2, adding a modifier into the magnesium chloride aqueous solution obtained in the step S1, and uniformly stirring to obtain a mixture A;

s3, uniformly stirring the engineering slag soil, the light burned magnesium oxide, the industrial waste slag, the fiber and the exciting agent to obtain a mixture B;

s4, adding the mixture A obtained in the step S2 into the mixture B obtained in the step S3 in a spraying mode, and uniformly stirring to obtain a mixture C;

and S5, filling the mixture C obtained in the step S4 into a mold, adopting a pressure forming process, demolding, and curing to obtain the engineering muck-based non-fired building material.

Further, the engineering muck is crushed to be less than 4.75mm in particle size.

Further, the Baume degree of the magnesium chloride aqueous solution is 22-30.

Further, the water content of the mixture C is 6-18%.

Furthermore, the molding pressure of the pressure molding process is 10MPa to 20 MPa.

Further, the relative humidity of maintenance is not lower than 90%; and/or the curing time is not less than 7 days.

The invention has the following beneficial effects:

the invention relates to a magnesium oxychloride cement-based muck non-fired building material, which comprises the following raw materials: engineering slag soil, light-burned magnesium oxide, magnesium chloride, industrial waste residue, fiber, a modifier and an excitant. The invention takes engineering slag soil as a main raw material, adopts magnesium oxychloride cement and industrial waste slag as a cementing material to cooperate with the solidification of the engineering slag soil to prepare the magnesium oxychloride cement-based slag soil non-fired building material, changes the engineering slag soil into valuable, and realizes the resource utilization of the engineering slag soil. The magnesium oxychloride cement has the characteristics of strong bonding performance and easy bonding with various materials, can be quickly solidified and hardened at normal temperature and normal pressure, and forms a building material with high brittleness and high strength. The main components of the mineral powder, the fly ash and the coal gangue powder are SiO₂And Al₂O₃The compound fertilizer has potential hydration activity, can quickly generate hydration reaction under the action of an exciting agent, and not only can improve the strength of a slag solidified body, but also can improve the durability of the slag solidified body. The disorderly distributed fibers have a reinforcing effect, so that the bending strength and the tensile strength of the magnesium oxychloride cement-based product can be greatly improved, and the toughness of the magnesium oxychloride cement-based product is improved. The modifier can effectively inhibit the halogen return of the magnesium oxychloride cement-based product. The magnesium oxychloride cement-based muck non-fired building material has the advantages of low cost, high strength and high durability under the synergistic action of the raw materials. The magnesium oxychloride cement-based muck baking-free building material realizes resource utilization of engineering muck, can consume a large amount of engineering muck, relieve urban pain points of ' muck enclosing city ', can develop a new product in the field of building materials, reduce exploitation of natural sandstone in the building industry, meet the requirements of building ' resource-saving and environment-friendly ' society, and is favorable for promoting ' non-waste citiesConstruction, and has good ecological benefit, social benefit and economic benefit.

The preparation method of the magnesium oxychloride cement-based muck non-fired building material comprises the following steps of firstly, adding magnesium chloride into water to prepare a magnesium chloride aqueous solution, and then adding a modifier to prepare a mixture A; then, uniformly stirring the engineering slag soil, the light burned magnesium oxide, the industrial waste residue, the fiber and the excitant to prepare a mixture B; and finally, adding the mixture A into the mixture B in a spraying mode, and uniformly stirring to prepare a mixture C. And (3) filling the mixture C into a mold, adopting a pressure forming process, and then demolding and maintaining to obtain the magnesium oxychloride cement-based muck baking-free building material. The mixture A is added into the mixture B in a spraying mode, the reason is mainly that engineering muck is high in viscosity and is difficult to stir uniformly when being directly mixed, and the spraying mode is favorable for uniformly mixing the magnesium chloride aqueous solution and the modifier into the mixture B. The preparation process of the magnesium oxychloride cement-based muck non-fired building material is simple, and the production needs a small field; by adopting a sintering-free process, a large amount of energy can be saved, and the method is low-carbon and environment-friendly. Therefore, the preparation method of the magnesium oxychloride cement-based muck non-fired building material has the characteristics of simple preparation process, no sintering, small production investment and the like.

In addition to the objects, features and advantages described above, other objects, features and advantages of the present invention are also provided. The present invention will be described in further detail below.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail with reference to examples.

The magnesium oxychloride cement-based muck non-fired building material comprises the following components in parts by mass: the engineering slag soil comprises 80 to 100 portions of dry weight, 5 to 30 portions of light-burned magnesia, 1 to 15 portions of magnesium chloride, 5 to 20 portions of industrial waste residue, 0.2 to 1.5 portions of fiber, 0.1 to 1.5 portions of modifier and 0.5 to 2 portions of excitant.

The magnesium oxychloride cement-based muck is free from being burnedBuilding material, the raw materials comprising: engineering slag soil, light-burned magnesium oxide, magnesium chloride, industrial waste residue, fiber, a modifier and an excitant. The invention takes engineering slag soil as a main raw material, adopts magnesium oxychloride cement and industrial waste slag as a cementing material to cooperate with the solidification of the engineering slag soil to prepare the magnesium oxychloride cement-based slag soil non-fired building material, changes the engineering slag soil into valuable, and realizes the resource utilization of the engineering slag soil. The magnesium oxychloride cement has the characteristics of strong bonding performance and easy bonding with various materials, can be quickly solidified and hardened at normal temperature and normal pressure, and forms a building material with high brittleness and high strength. The main components of the mineral powder, the fly ash and the coal gangue powder are SiO₂And Al₂O₃The compound fertilizer has potential hydration activity, can quickly generate hydration reaction under the action of an exciting agent, and not only can improve the strength of a slag solidified body, but also can improve the durability of the slag solidified body. The disorderly distributed fibers have a reinforcing effect, so that the bending strength and the tensile strength of the magnesium oxychloride cement-based product can be greatly improved, and the toughness of the magnesium oxychloride cement-based product is improved. The modifier can effectively inhibit the halogen return of the magnesium oxychloride cement-based product. The magnesium oxychloride cement-based muck non-fired building material has the advantages of low cost, high strength and high durability under the synergistic action of the raw materials. The magnesium oxychloride cement-based muck baking-free building material realizes resource utilization of engineering muck, can consume a large amount of engineering muck, relieves urban pain points of 'muck surrounding cities', can develop a new product in the field of building materials, reduces exploitation of natural gravels in the building industry, meets the requirements for building 'resource-saving and environment-friendly' society, is favorable for promoting the construction of 'waste-free cities', and has better ecological benefit, social benefit and economic benefit.

The engineering muck is soil muck generated by foundation pit excavation or underground engineering construction, and the engineering muck mainly comprises clay, and has high water content and high viscosity, so that the engineering muck has high resource utilization difficulty. The light-burned magnesium oxide and magnesium chloride are main raw materials of magnesium oxychloride cement, and the magnesium oxychloride cement has the characteristics of strong bonding performance and easy bonding with various materials, can be quickly coagulated and hardened under the normal-temperature and normal-pressure curing condition, and forms a building material with high brittleness and high strength. Compared with the traditional engineering muck cementing material (cement, lime and the like), the magnesium oxychloride cement-based muck non-sintered material has higher strength and shorter time for setting and hardening under the condition of the same mixing amount. The magnesium oxychloride cement-based muck baking-free building material is prepared by curing engineering muck in cooperation with industrial waste residues, and the occupation ratio of the engineering muck is up to 65-85%. The method realizes higher utilization rate of the engineering slag soil, has higher mechanical strength, better durability, compression strength up to 60MPa, shorter production period, low production cost and wide application prospect.

Preferably, the engineering slag soil comprises 85 to 95 parts (dry weight), 8 to 25 parts of light-burned magnesium oxide, 2 to 9 parts of magnesium chloride, 8 to 16 parts of industrial waste slag, 0.2 to 1.0 part of fiber, 0.3 to 1.0 part of modifier and 0.5 to 1.5 parts of excitant. The magnesium oxychloride cement-based muck non-fired building material obtained by the proportion has higher compressive strength and better durability. More preferably, the engineering slag soil is 85 to 95 parts (by dry weight), the light-burned magnesia is 10 to 20 parts, the magnesium chloride is 3 to 6 parts, the industrial slag is 10 to 15 parts, the fiber is 0.3 to 0.6 part, the modifier is 0.3 to 0.6 part, and the excitant is 0.6 to 1.2 parts.

In this embodiment, the engineering muck is soil-like muck generated by excavation of a foundation pit and/or construction of an underground engineering. And/or the water content of the engineering muck is lower than 3 percent. The magnesium oxychloride cement-based muck baking-free building material is prepared by taking engineering muck as a main raw material, wherein the engineering muck is soil muck. The magnesium oxychloride cement-based muck baking-free building material realizes resource utilization of engineering muck, can consume a large amount of engineering muck, reduce social problems of occupation of a large amount of land by filling and filling the engineering muck, environmental pollution, potential safety hazard and the like, can develop a new product in the field of building materials, reduce the requirements of the building industry on natural gravels and environmental damage caused by exploitation of the natural gravels, meet the requirements of China for building a resource-saving and environment-friendly society, and is also favorable for promoting the construction of a waste-free city, so that the magnesium oxychloride cement-based muck baking-free building material has good ecological benefit, environmental benefit and social benefit. The engineering muck is dried or baked before use, and the water content of the engineering muck is lower than 3 percent. The main component of the engineering muck is clay, the water content of the clay is higher and the viscosity of the clay is higher, and the clay is difficult to be uniformly stirred with other raw materials. After the engineering slag soil is air-dried or dried, the crushing treatment and the uniform stirring with other raw materials are facilitated.

In this embodiment, the industrial waste residue is one or more of mineral powder, fly ash or coal gangue powder. And/or the fineness of the industrial waste residue is not less than 200 meshes. The industrial waste residue is one or more of mineral powder, fly ash or coal gangue powder, and the main component of the industrial waste residue is SiO₂And Al₂O₃Has potential hydration activity. The industrial waste residue is ground to the fineness of not less than 200 meshes, the hydration activity of the industrial waste residue is improved through the physical action, and the hydration activity of the industrial waste residue is further excited under the chemical action of the exciting agent, so that the hydration reaction can be more quickly carried out, the engineering waste residue is solidified with the magnesium oxychloride cement in a synergistic manner, and the mechanical strength and the durability of the magnesium oxychloride cement-based waste residue baking-free building material are improved.

In this embodiment, the fiber is at least one of a crop straw fiber and a polypropylene fiber. And/or the length of the fibres does not exceed 20 mm. The fiber improves the cracking resistance of the magnesium oxychloride cement-based muck non-fired building material and overcomes the defect of large brittleness of magnesium oxychloride cement-based products. The length of the fiber is not more than 20mm, which is beneficial to the uniform dispersion of the fiber in the mixture, thereby effectively preventing the generation and the expansion of micro-cracks in the matrix, improving the cracking resistance of the magnesium oxychloride cement-based burning-free muck building material and obviously improving the toughness of the magnesium oxychloride cement-based burning-free muck building material.

In this embodiment, the modifier is one or more of phosphate, sulfate, phosphoric acid, and silicon powder. The modifier can effectively inhibit the halogen return of the magnesium oxychloride cement product.

In this embodiment, the activator is one or more of sodium hydroxide, sodium sulfate, sodium carbonate, or sodium silicate. The activator can effectively excite the activity of mineral powder, fly ash and gangue powder to form geopolymer gelled material with high strength and good durability.

According to another aspect of the present invention, there is also provided a method for preparing the above magnesium oxychloride cement-based muck unfired building material, comprising the following steps:

s1, adding magnesium chloride into water, and uniformly stirring to obtain a magnesium chloride aqueous solution;

s2, adding a modifier into the magnesium chloride aqueous solution obtained in the step S1, and uniformly stirring to obtain a mixture A;

s3, uniformly stirring the engineering slag soil, the light burned magnesium oxide, the industrial waste slag, the fiber and the exciting agent to obtain a mixture B;

s4, adding the mixture A obtained in the step S2 into the mixture B obtained in the step S3 in a spraying mode, and uniformly stirring to obtain a mixture C;

and S5, filling the mixture C obtained in the step S4 into a mold, adopting a pressure forming process, demolding, and curing to obtain the engineering muck-based non-fired building material.

The preparation method of the magnesium oxychloride cement-based muck non-fired building material comprises the following steps of firstly, adding magnesium chloride into water to prepare a magnesium chloride aqueous solution, and then adding a modifier to prepare a mixture A; then, uniformly stirring the engineering slag soil, the light burned magnesium oxide, the industrial waste residue, the fiber and the excitant to prepare a mixture B; and finally, adding the mixture A into the mixture B in a spraying mode, and uniformly stirring to prepare a mixture C. And (3) filling the mixture C into a mold, adopting a pressure forming process, and then demolding and maintaining to obtain the magnesium oxychloride cement-based muck baking-free building material. The mixture A is added into the mixture B in a spraying mode, the reason is mainly that engineering muck is high in viscosity and is difficult to stir uniformly when being directly mixed, and the spraying mode is favorable for uniformly mixing the magnesium chloride aqueous solution and the modifier into the mixture B. The preparation process of the magnesium oxychloride cement-based muck non-fired building material is simple, and the production needs a small field; by adopting a sintering-free process, a large amount of energy can be saved, and the method is low-carbon and environment-friendly. Therefore, the preparation method of the magnesium oxychloride cement-based muck non-fired building material has the characteristics of simple preparation process, no sintering, small production investment and the like. The preparation method of the magnesium oxychloride cement-based muck non-fired building material solves the problems that the muck in the curing engineering of the traditional cementing materials (cement, lime and gypsum) has low compressive strength and is difficult to be made into building material products for popularization and application.

In this embodiment, the engineering slag soil is crushed to have a particle size of less than 4.75 mm. The engineering slag soil usually contains large broken stones, and the particle size of the broken stones affects the forming and the performance of products. The engineering slag soil is crushed by a roll crusher, so that the particle size of the engineering slag soil is kept in a reasonable range, the homogeneity of the engineering slag soil particles is improved, and the stability of the performance of the magnesium oxychloride cement-based slag soil baking-free building material is favorably ensured. The magnesium oxychloride cement-based muck baking-free building material is mainly used for producing building materials such as road bricks, standard bricks, building blocks and the like, and the size of the product is small, so that the particle size of the engineering muck particles is smaller than 4.75mm, and the magnesium oxychloride cement-based muck baking-free building material product is easy to form and stable in performance.

In this embodiment, the Baume degree of the magnesium chloride aqueous solution is 22 to 30. The magnesium chloride is an important component material of magnesium oxychloride cement. The magnesium oxychloride cement is prepared by using light calcined powder obtained by calcining magnesite or ash (main component is MgO) obtained by calcining dolomite at low temperature, and using magnesium chloride hexahydrate (MgCl)₂·6H₂O) or the like as a blending agent, and water is added thereto to form a hardened cement. The test result shows that the hydration product composition of the magnesium oxychloride cement is mainly 518 phase, Mg (OH)₂When the auxiliary material is used, the cured product has the best performance, and when the baume degree of the magnesium chloride aqueous solution is 22-30, MgO/MgCl₂When the molar ratio of (a) to (b) is 5-13, 518 phases in the hydration product account for more, Mg (OH)₂The ratio is less, and the strength of a hardened body is higher.

In this example, the water content of the mixture C was 6% to 18%. The engineering muck material is molded under pressure to have the optimal water content, and the maximum dry density and the higher limit pressure can be obtained under the condition of the water content, so that the engineering muck blank with higher strength is obtained. Meanwhile, the optimum baume degree of the magnesium chloride is 22-30, and the water content of the mixture is limited. Test results show that when the water content is 6-18%, the magnesium oxychloride cement-based muck baking-free building material can be molded under higher pressure to obtain a more compact muck blank, and can also enable magnesium chloride to react under a better baume degree to obtain a magnesium oxychloride cement-based muck baking-free building material with higher strength under the physical and chemical synergistic effects.

In this embodiment, the pressure forming process has a forming pressure of 10 to 20 MPa. The pressure forming process is adopted, the limit pressure of different materials and the mixing ratio of the materials is different, and when the pressure exceeds the limit pressure, the pressure can not play a role and can cause the damage of a blank body. The invention determines the forming pressure range to be 10 MPa-20 MPa through tests.

In this example, the relative humidity of the curing is not less than 90%; and/or the curing time is not less than 7 days.

Examples

Example 1

The magnesium oxychloride cement-based muck non-fired building material comprises the following components in parts by mass: 100 parts of engineering slag soil by dry weight, 8 parts of light-burned magnesium oxide, 2 parts of magnesium chloride, 10 parts of fly ash, 0.4 part of crop straw fiber, 0.5 part of sodium phosphate, 0.9 part of sodium hydroxide and 0.3 part of sodium silicate.

The preparation method of the magnesium oxychloride cement-based muck non-fired building material comprises the following steps:

s1, adding magnesium chloride into water, and uniformly stirring to obtain a magnesium chloride solution with a Baume degree of 22;

s2, adding sodium phosphate into the magnesium chloride solution obtained in the step S1, and uniformly stirring to obtain a mixture A;

s3, drying or air-drying the engineering muck until the water content is lower than 3%, crushing until the particle size is smaller than 4.75mm, and uniformly stirring with light-burned magnesium oxide, fly ash, crop straw fiber, sodium hydroxide and sodium silicate to prepare a mixture B;

s4, adding the mixture A in the step S2 into the mixture B in the step S3 in a spraying mode, and stirring uniformly to obtain a mixture C, wherein the water content of the mixture C is 7%;

s5, filling the mixture C obtained in the step S4 into a die, forming in a hydraulic press with the pressure of 12MPa, demolding, and curing in a curing room with the relative humidity not lower than 90% for 7 days to form the magnesium oxychloride cement-based muck non-fired building material.

Example 2

The magnesium oxychloride cement-based muck non-fired building material comprises the following components in parts by mass: 100 parts of engineering slag soil by dry weight, 12 parts of light-burned magnesium oxide, 4 parts of magnesium chloride, 12 parts of mineral powder, 0.6 part of polypropylene fiber, 0.6 part of phosphoric acid, 0.5 part of sodium sulfate and 0.8 part of sodium silicate.

The preparation method of the magnesium oxychloride cement-based muck non-fired building material comprises the following steps:

s1, adding magnesium chloride into water, and uniformly stirring to obtain a magnesium chloride solution with a Baume degree of 25;

s2, adding phosphoric acid into the magnesium chloride solution obtained in the step S1, and uniformly stirring to obtain a mixture A;

s3, drying or air-drying the engineering muck until the water content is lower than 3%, crushing until the particle size is smaller than 4.75mm, and uniformly stirring with light-burned magnesium oxide, mineral powder, polypropylene fibers, sodium sulfate and sodium silicate to prepare a mixture B;

s4, adding the mixture A in the step S2 into the mixture B in the step S3 in a spraying mode, and stirring uniformly to obtain a mixture C, wherein the water content of the mixture C is 10%;

s5, filling the mixture C obtained in the step S4 into a die, forming in a hydraulic press with the pressure of 10MPa, demolding, and curing in a curing room with the relative humidity not lower than 90% for 7 days to form the magnesium oxychloride cement-based muck non-fired building material.

Example 3

The magnesium oxychloride cement-based muck non-fired building material comprises the following components in parts by mass: 100 parts of engineering slag soil by dry weight, 20 parts of light-burned magnesium oxide, 6 parts of magnesium chloride, 5 parts of coal gangue powder, 0.8 part of crop straw fiber, 0.8 part of sodium phosphate, 0.3 part of sodium sulfate, 0.6 part of sodium carbonate and 0.2 part of sodium silicate.

The preparation method of the magnesium oxychloride cement-based muck non-fired building material comprises the following steps:

s1, adding magnesium chloride into water, and uniformly stirring to obtain a magnesium chloride solution with a Baume degree of 30;

s2, adding sodium phosphate into the magnesium chloride solution obtained in the step S1, and uniformly stirring to obtain a mixture A;

s3, drying or air-drying the engineering muck until the water content is lower than 3%, crushing until the particle size is smaller than 4.75mm, and uniformly stirring with light-burned magnesium oxide, coal gangue powder, crop straw fibers, sodium sulfate, sodium carbonate and sodium silicate to prepare a mixture B;

s4, adding the mixture A in the step S2 into the mixture B in the step S3 in a spraying mode, and stirring uniformly to obtain a mixture C, wherein the water content of the mixture C is 11%;

s5, filling the mixture C obtained in the step S4 into a die, forming in a hydraulic press with the pressure of 10MPa, demolding, and curing in a curing room with the relative humidity not lower than 90% for 7 days to form the magnesium oxychloride cement-based muck non-fired building material.

Carrying out unconfined compressive strength, softening coefficient and frost resistance tests on the magnesium oxychloride cement-based muck unfired building material prepared in the embodiments 1, 2 and 3, wherein the unconfined compressive strength is carried out according to the national standard cement soil mixing proportion design rule (JGJ/T233-2011); the softening coefficient and the freezing resistance test are carried out according to the national standard wall brick test method (GB/T2542-. The test results are shown in table 1.

TABLE 1 test results of examples 1 to 3

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.