CN116715485A - Gangue masonry mortar and preparation method thereof - Google Patents

Abstract

The application provides gangue masonry mortar and a preparation method thereof, and relates to the technical field of gangue application. The composite material comprises the following components in parts by weight: 80-140 parts of cement, 140-840 parts of pretreated coal gangue, 0-740 parts of aggregate, 0-50 parts of fly ash, 0.1-0.5 part of plasticizer, 0-0.1 part of water-retaining agent and 0-0.15 part of sodium gluconate. In the application, coal gangue is used for replacing part of natural sand, so that the problems of increasing shortage of natural sand aggregate and huge pressure on ecological environment caused by excessive exploitation are solved, and the treatment difficulty of large solid wastes is reduced. The technical scheme that the masonry mortar is prepared by directly crushing and screening a large amount of gangue raw materials without high-energy treatment is obtained by selecting proper raw materials and proportions. The whole formula is simple and reasonable, the consumption of the gangue is high, the cost of all the used raw materials is low, the raw materials are easy to purchase, and the production cost of the mortar can be effectively reduced.

Description

Gangue masonry mortar and preparation method thereof

Technical Field

The application belongs to the technical field of gangue application, and particularly relates to gangue masonry mortar and a preparation method thereof.

Background

The gangue is a solid waste with low carbon content and high ash content discharged in the coal exploitation and processing process, and is rock mixed with organic compounds and inorganic compounds deposited together with coal in the coal formation process. The output of the method generally accounts for 10% -15% of the output of coal, and the discharge amount accounts for about 1/4 of the discharge amount of industrial waste residues in China. The waste residues occupy land resources, cause subsidence of the earth surface, water and soil loss, and even cause geological desertification, ecological environment destruction and the like. At present, the utilization measures of coal gangue in China are more, and the utilization of building materials mainly comprises the steps of coal gangue brickmaking, partial substitution of cement raw materials, preparation of ceramic materials and the like, and the technologies are relatively mature. The processing treatment of coal gangue as cementing material or coarse aggregate to prepare concrete has been more studied, and due to the larger randomness of coal gangue, most of the researches are focused on the analysis of the influence on the performance of hardened slurry, and no corresponding standard and specification have been provided.

At present, coal gangue is used for replacing aggregate to prepare concrete or mortar materials, and common problems include large difference between the components and chemical activities of the coal gangue, lower self strength than natural crushed stone, large porosity, high water absorption rate and the like. The mixing water is absorbed in a large amount in the process of stirring, the workability of the mixture is affected, and the shrinkage of mortar or concrete is adversely affected, so that the problem of volume stability of the prepared material is reduced. In order to solve the problems, the prior researches mainly adopt the coal gangue calcination grinding as cement mixed materials or mortar and concrete admixture. However, the treatment method has high energy consumption, and the activity fluctuation of the treatment method can restrict the resource production.

In conclusion, how to design the formula of the low-energy-consumption gangue masonry mortar through the combination and proportioning of raw materials, not only can the gangue raw materials be applied in a large amount and the solid waste be reduced, but also the adverse effect of the gangue raw materials on the mortar can be solved, and the method is a problem to be solved urgently by the technicians in the field.

Disclosure of Invention

The application aims to provide gangue masonry mortar. In the application, coal gangue is used for replacing part of natural sand, so that the problems of increasing shortage of natural sand aggregate and huge pressure on ecological environment caused by excessive exploitation are solved, and the treatment difficulty of large solid wastes is reduced. The technical scheme that the masonry mortar is prepared by directly crushing and screening a large amount of gangue raw materials without high-energy treatment is obtained by selecting proper raw materials and proportions. The whole formula is simple and reasonable, the consumption of the gangue is high, the cost of all the used raw materials is low, the raw materials are easy to purchase, and the production cost of the mortar can be effectively reduced.

In order to achieve the aim, the application provides gangue masonry mortar, which comprises the following components in parts by weight:

80-140 parts of cement, 140-840 parts of pretreated coal gangue, 0-740 parts of aggregate, 0-50 parts of fly ash, 0.1-0.5 part of plasticizer, 0-0.1 part of water-retaining agent and 0-0.15 part of sodium gluconate.

In a preferred embodiment, the composition comprises the following components in parts by weight: 90-130 parts of cement, 400-840 parts of pretreated coal gangue, 0-440 parts of aggregate, 10-50 parts of fly ash, 0.15-0.45 part of plasticizer and 0-0.15 part of sodium gluconate.

In a preferred embodiment, the composition comprises the following components in parts by weight: 90-130 parts of cement, 150-190 parts of pretreated coal gangue, 700-740 parts of aggregate, 0.15-0.45 part of plasticizer and 0-0.1 part of water-retaining agent.

In a preferred embodiment, the cement comprises one or more of PO42.5 cement, PC42.5 cement, cement clinker powder; preferably, the specific surface area of the cement is more than or equal to 350m ² /kg; more preferably, the cement is PC42.5 portland cement.

In a preferred embodiment, the coal gangue is selected from one or two of white coal gangue and water-washed black coal gangue; preferably, the gangue component comprises Al ₂ O ₃ 13-25％、SiO ₂ 52-74％、Fe ₂ O ₃ 3-4％、CaO 0-1％、MgO 0-2％、Na ₂ O 1-3％、K ₂ O1-3% and trace rare elements (gallium, vanadium, titanium, cobalt).

More preferably, when the coal gangue is white coal gangue, the coal gangue comprises the following components in parts by weight:

90-130 parts of cement, 800-840 parts of pretreated coal gangue, 0-40 parts of aggregate, 10-50 parts of fly ash and 0.15-0.45 part of plasticizer; or (b)

90-130 parts of cement, 150-190 parts of pretreated coal gangue, 700-740 parts of aggregate and 0.15-0.45 part of plasticizer.

More preferably, when the coal gangue is black water-washed coal gangue, the coal gangue comprises the following components in parts by weight:

90-130 parts of cement, 400-440 parts of pretreated coal gangue, 400-440 parts of aggregate, 10-50 parts of fly ash, 0.15-0.45 part of plasticizer and 0.05-0.15 part of sodium gluconate; or (b)

90-130 parts of cement, 150-190 parts of pretreated coal gangue, 700-740 parts of aggregate, 0.15-0.45 part of plasticizer and 0.05-0.1 part of water-retaining agent.

In a preferred embodiment, the pretreatment steps of the coal gangue are as follows: crushing and grading white coal gangue or water-washed black coal gangue, controlling the particle size of the screening material to be 0.6-3mm and 40-50% by mass, the particle size to be less than 30% by mass and the residual particle size to be 0.075-0.6 mm.

In a preferred embodiment, the black coal gangue is used as a raw material, and is washed for 2-5min by adopting a mechanical washing mode, and the black coal gangue is dried for standby after the surface is removed.

In a preferred embodiment, the aggregate comprises one or more of stone powder, natural sand and machine-made sand, and preferably, the aggregate comprises the following components in percentage by mass: (1.5-3.5) and mixing.

In a preferred embodiment, the fly ash is tertiary fly ash.

The application also aims to provide a preparation method of the gangue masonry mortar, which is obtained by uniformly mixing powder and adding water for mixing, has the advantages of simple preparation method, high efficiency and low energy consumption, has no limit on production equipment and environment, and can be prepared in large-scale industrial production.

In order to achieve the above purpose, the application provides a preparation method of gangue masonry mortar, which specifically comprises the following steps:

weighing cement, coal gangue, aggregate, fly ash, plasticizer, water-retaining agent and sodium gluconate according to the formula amount; mixing the powder, adding water and stirring uniformly to obtain the gangue masonry mortar.

In a preferred embodiment, the solid-liquid mass ratio of the powder to the water is 1: (0.1-1).

Compared with the prior art, the technical scheme of the application has the following advantages:

1. in the application, a large amount of coal gangue is adopted as mortar raw material, and the application has the following advantages:

resources are saved: the gangue is a solid waste, and the use of the gangue can save the exploitation cost of other more precious aggregates such as river sand, mountain stone and other resources.

Environmental protection and energy saving: the gangue has wide sources, and the gangue is used as aggregate without pollution and damage to the environment. Meanwhile, the energy and consumption required for transporting and processing the gangue aggregate are less, and the energy conservation is facilitated.

Increasing the strength: the gangue has higher hardness and strength, so that the mechanical property of the mortar can be improved, and the strength and durability are improved.

The cost is reduced: the gangue is a waste, and the utilization of the gangue can reduce the production cost of mortar and improve the economic benefit.

Low water absorption: gangue adsorbs water but is generally more stable than natural stone and therefore has relatively less of a void.

2. The gangue adopted in the application can be directly crushed and graded for use without calcining and grinding, has low requirements on energy consumption and treatment equipment, and is especially suitable for large-scale production.

Detailed Description

The following detailed description of the application is presented to provide those skilled in the art with a better understanding of the application, but it should be understood that the scope of the application is not limited to the detailed description.

The embodiment of the application solves the technical problems of small coal gangue consumption and high energy consumption processing treatment of coal gangue in the mortar in the prior art by providing the coal gangue masonry mortar and the preparation method thereof.

The technical scheme in the application is to solve the problems, and the technical scheme is verified by exploratory test results:

firstly, coal gangue raw materials are white and black, and through experimental comparison, the black influences the performance of the additive in the product, and the product has high apparent density, heavy material, poor workability and larger consistency loss, and influences the workability. And the black gangue is directly used after being sorted and crushed without being washed by water, so that the performances such as strength and consistency loss rate of the black gangue are also affected. Therefore, the black gangue should be washed with water to remove powder, and the fly ash is added for use, so that the water adding amount of the mortar can be reduced.

The black coal gangue after water washing is compounded with the aggregate of the factory, so that the influence on the early strength of common mortar is small, the workability is improved, but the consistency loss is influenced, the construction operation time is influenced, and the normal use is regulated by an additive. And then the mixing amount of the black gangue is reduced, the consistency loss can be improved, the construction operation time is prolonged, but the water retention performance index is reduced, and the performance needs to be improved by the additive.

The white gangue is singly used as aggregate to be mixed with mortar, and is compounded with the aggregate of the factory, and the prepared common mortar can be normally used and accords with the standard of the existing products.

The following describes the technical scheme of the application in detail through specific embodiments:

unless otherwise indicated, the technical means used in the present application are conventional means well known to those skilled in the art, and various raw materials, reagents, instruments, equipment, etc. used in the present application are commercially available or can be prepared by existing methods. The reagents used in the application are analytically pure unless otherwise specified.

The coal gangue used in the embodiment of the application is white coal gangue and black coal gangue purchased from Jizhong energy perpetual ore manufacturers, and the main components are Al ₂ O ₃ 、SiO ₂ In addition, fe is contained in different amounts ₂ O ₃ 、CaO、MgO、Na ₂ O、K ₂ O、P ₂ O ₅ 、SO ₃ And trace rare elements (gallium, vanadium, titanium, cobalt); specifically, the gangue component comprises Al ₂ O ₃ 13-25％、SiO ₂ 52-74％、Fe ₂ O ₃ 3-4％、CaO0-1％、MgO 0-2％、Na ₂ O 1-3％、K ₂ O1-3% and trace rare elements (gallium, vanadium, titanium, cobalt).

The plasticizer used in the examples of the present application was purchased from Beijing golden corner mortar Co., ltd; the water-retaining agent used in the embodiment of the application is purchased from Tay Ruitai cellulose Limited company, and the model is cellulose ether 4 ten thousand (HPMC); the sodium gluconate used in the examples of the present application was purchased from Shandong Fuyang Biotech Co., ltd. The aggregate used was purchased from beijing corner mortar limited.

In the present application, the parts by weight may be those known in the art such as mu g, mg, g, kg, or may be multiples thereof such as 1/10, 1/100, 10 times, 100 times, etc.

Test example 1

The formula comprises the following components: 115 parts of PC42.5 cement, 885 parts of gangue and 0.3 part of plasticizer, wherein the gangue is respectively black gangue and white gangue to be tested, the black gangue and the white gangue are crushed and classified, the particle size in the screened material is controlled to be 45% by mass percent, the particle size is controlled to be less than 30% by mass percent, and the residual particle size is between 0.075 and 0.6 mm.

The preparation method comprises the following steps: after the prepared powder is uniformly mixed (no sequence is added in the powder), the black gangue group is added with water accounting for 19.4% of the mass of the powder, and the white gangue group is added with water accounting for 18.5% of the mass of the powder, so that the initial consistence of the two mortars is controlled. The slurry was stirred with a mortar stirrer at the same stirring speed and stirring time to obtain a uniform slurry.

According to GB/T25181-2019 ready-mixed mortar national standard and JGJ/T70-2009 building mortar basic performance test method standard, the two samples are tested for apparent density, consistency loss, 28d compressive strength and 14d tensile bonding strength. The results are shown in Table 1.

TABLE 1

Through experimental data analysis, the black gangue group is compared with the white gangue group, the black gangue influences the performance of the additive in the product, the apparent density of the product is high, the material is heavy, the construction performance is poor, the consistency loss is large, and the construction performance is influenced.

Test example 2

Group 1 test formulation: 110 parts of PC42.5 cement, 50 parts of fly ash (grade II), 420 parts of aggregate, 420 parts of black coal gangue and 0.35 part of plasticizer; wherein the aggregate comprises 200 parts by weight of natural sand and 220 parts by weight of machine-made sand.

Group 2 test formulations: 110 parts of PC42.5 cement, 50 parts of fly ash (grade II), 420 parts of aggregate, 420 parts of black coal gangue and 0.35 part of plasticizer; wherein the aggregate comprises 200 parts by weight of natural sand and 220 parts by weight of machine-made sand.

The difference between the tests in the 1 st and the 2 nd is that the dosage of cement and fly ash is adjusted, and the dosage of the rest raw materials is consistent.

And washing the black gangue with mechanical water for 5min, removing the black surface, and airing for standby.

Group 3 test formulation: 110 parts of PC42.5 cement, 50 parts of fly ash (grade II), 420 parts of aggregate, 420 parts of water-washed black coal gangue and 0.35 part of plasticizer; wherein the aggregate comprises 200 parts by weight of natural sand and 220 parts by weight of machine-made sand.

Group 4 test formulation: 120 parts of PC42.5 cement, 40 parts of fly ash (grade II), 420 parts of aggregate, 420 parts of water-washed black coal gangue and 0.35 part of plasticizer; wherein the aggregate comprises 200 parts by weight of natural sand and 220 parts by weight of machine-made sand.

The test of the 3 rd and 4 th groups is different from the test of the 1 st and 2 nd groups in that the 1 st and 2 nd groups adopt common black gangue and are not subjected to water washing treatment; 3. and 4, adopting the black coal gangue after water washing.

Group 5 test formulation: 110 parts of PC42.5 cement, 50 parts of fly ash (class II), 840 parts of white gangue and 0.35 part of plasticizer.

Group 6 test formulation: 120 parts of PC42.5 cement, 40 parts of fly ash (class II), 840 parts of white gangue and 0.35 part of plasticizer.

The difference between the tests in the 5 th and 6 th groups is that the dosage of cement and fly ash is adjusted, and the dosage of the rest raw materials is consistent.

Crushing and grading 1-6 groups of tested coal gangue respectively, controlling the particle size of the screened material to be 0.6-3mm and 45% of the mass fraction, controlling the particle size to be less than 30% of the mass fraction of 0.075mm, and controlling the residual particle size to be 0.075-0.6 mm.

The preparation method comprises the following steps: uniformly mixing the prepared powder (no sequence of powder addition);

common black gangue group: the test of the 1 st group adds water with the mass of 18.8 percent of powder, and the test of the 2 nd group adds water with the mass of 18.4 percent of powder;

washing black coal gangue group: the 3 rd group test is added with water with the mass of 16.4% of powder, and the 4 th group test is added with water with the mass of 15.4% of powder;

white gangue group: the 5 th test adds water with 15.9% of the powder mass, and the 6 th test adds water with 15.1% of the powder mass, so as to control the initial consistence of the four groups of mortars. The slurry was stirred with a mortar stirrer at the same stirring speed and stirring time to obtain a uniform slurry.

According to GB/T25181-2019 ready mixed mortar national standard and JGJ/T70-2009 building mortar basic performance test method standard, the four groups of tests are tested for apparent density, consistency loss, 28d compressive strength and 14d tensile bond strength. The results are shown in Table 2.

TABLE 2

Through experimental data analysis, the white gangue in groups 5 and 6 can be normally used, and the performance of the white gangue meets the product standard.

The common black coal gangue of the 1 st and the 2 nd groups has poor effect, and the 3 rd and the 4 th groups are used after the black coal gangue is washed, so that the water adding amount of plastering mortar can be obviously reduced, and the mortar has better performance.

On the other hand, although the black gangue after water washing has little influence on the early strength of masonry mortar after being compounded with the aggregate of the factory, the workability is improved, but the consistency loss is influenced, and the construction operation time is influenced, so that the scheme requiring the black gangue still needs to be continuously improved.

Test example 3

And washing the black gangue with mechanical water for 5min, removing the black surface, and airing for standby.

Test formulation of group 1': 110 parts of PC42.5 cement, 720 parts of aggregate, 170 parts of water-washed black coal gangue and 0.35 part of plasticizer; wherein the aggregate comprises 215 parts by weight of stone powder, 305 parts by weight of natural sand and 200 parts by weight of machine-made sand.

Group 2' test formulation: 110 parts of PC42.5 cement, 720 parts of aggregate, 170 parts of white gangue and 0.35 part of plasticizer; wherein the aggregate comprises 215 parts by weight of stone powder, 305 parts by weight of natural sand and 200 parts by weight of machine-made sand.

The tests in groups 1 and 2' are different in adjustment of the types of the coal gangue, and the amounts of the rest raw materials are consistent.

Crushing and grading the coal gangue tested in the groups 1 and 2 respectively, controlling the particle size in the screening material to be 0.6-3mm and 45% of the mass fraction, controlling the particle size to be less than 30% of the mass fraction of 0.075mm, and controlling the residual particle size to be 0.075-0.6 mm.

The preparation method comprises the following steps: after the prepared powder is uniformly mixed (no sequence of powder addition), water accounting for 14.3% of the powder mass is added in the test of the 1 'group, and water accounting for 14.4% of the powder mass is added in the test of the 2' group, so that the initial consistencies of the two groups of mortar are controlled to be consistent. The slurry was stirred with a mortar stirrer at the same stirring speed and stirring time to obtain a uniform slurry.

According to GB/T25181-2019 ready mixed mortar national standard and JGJ/T70-2009 building mortar basic performance test method standard, the four groups of tests are tested for apparent density, consistency loss, 28d compressive strength and 14d tensile bond strength. The results are shown in Table 3.

TABLE 3 Table 3

Through experimental data analysis, the white gangue can be normally used, and the performance of the white gangue meets the product standard.

The blending amount of the black gangue is reduced, the consistency loss can be improved, the construction operation time is prolonged, but the water retention performance index is reduced, so that the water retention performance index is further adjusted and optimized.

Through the actual measurement data and a great amount of optimization exploration, the application provides the gangue masonry mortar and a preparation method thereof.

Examples 1-3 have the formulations shown in Table 4:

TABLE 4 Table 4

In table 4, the method of washing coal gangue with water and the method of pretreatment of coal gangue are all completely identical to those of test example 3.

The preparation method comprises the following steps: and (3) uniformly mixing the prepared powder (the powder is added in no sequence), adding water according to the formula amount, and uniformly stirring to obtain the product.

According to GB/T25181-2019 ready mixed mortar national standard and JGJ/T70-2009 building mortar basic performance test method standard, the four groups of tests are tested for apparent density, consistency loss, 28d compressive strength and 14d tensile bond strength. The results are shown in Table 5.

TABLE 5

As can be seen from Table 5, the formulation and the dosage of the embodiment 1/2/5 can effectively solve the problems of excessive consistency loss of the black water-washed coal gangue in the test example 2 and too low water retention rate of the black water-washed coal gangue in the test example 3, thereby expanding the utilization mode of the black coal gangue and providing the optimal formulation dosage of the black water-washed coal gangue with excellent technical effects under different doping amounts. Not only solves the problem that natural sand aggregates are increasingly short, and the excessive exploitation causes huge pressure to the ecological environment, but also reduces the difficult problem of processing large solid wastes. The technical scheme of adopting white gangue as raw materials in the embodiment 3/4/6 can directly adopt the white gangue through reasonable formula design, reduces the consumption of aggregate and auxiliary agent, and has the effect of simplifying the formula.

The foregoing descriptions of specific exemplary embodiments of the present application are presented for purposes of illustration and description. It is not intended to limit the application to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain the specific principles of the application and its practical application to thereby enable one skilled in the art to make and utilize the application in various exemplary embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the application be defined by the claims and their equivalents.

Claims (10)

1. The gangue masonry mortar is characterized by comprising the following components in parts by weight:

80-140 parts of cement, 140-840 parts of pretreated coal gangue, 0-740 parts of aggregate, 0-50 parts of fly ash, 0.1-0.5 part of plasticizer, 0-0.1 part of water-retaining agent and 0-0.15 part of sodium gluconate.

2. The gangue masonry mortar of claim 1, comprising the following components in parts by weight: 90-130 parts of cement, 400-840 parts of pretreated coal gangue, 0-440 parts of aggregate, 10-50 parts of fly ash, 0.15-0.45 part of plasticizer and 0-0.15 part of sodium gluconate.

3. The gangue masonry mortar of claim 1, comprising the following components in parts by weight: 90-130 parts of cement, 150-190 parts of pretreated coal gangue, 700-740 parts of aggregate, 0.15-0.45 part of plasticizer and 0-0.1 part of water-retaining agent.

4. The gangue masonry mortar of claim 1, wherein the cement comprises one or more of PO42.5 cement, PC42.5 cement, cement clinker powder.

5. The gangue masonry mortar of claim 1, wherein the gangue is selected from one or both of white gangue or water-washed black gangue;

the pretreatment steps of the coal gangue are as follows: crushing and grading white coal gangue or water-washed black coal gangue, controlling the particle size of the screening material to be 0.6-3mm and 40-50% by mass, the particle size to be less than 30% by mass and the residual particle size to be 0.075-0.6 mm.

6. The gangue masonry mortar of claim 5, wherein the black gangue is washed by mechanical washing for 2-5min, and the black gangue is dried for standby after removing the black surface.

7. The gangue masonry mortar of claim 1, wherein the aggregate comprises one or more of stone dust, natural sand, mixed natural sand, and machine-made sand.

8. The gangue masonry mortar of claim 1, wherein the fly ash is tertiary fly ash.

9. A method of preparing a gangue masonry mortar as claimed in any one of claims 1 to 8 comprising the steps of:

weighing cement, coal gangue, aggregate, fly ash, plasticizer, water-retaining agent and sodium gluconate according to the formula amount; mixing the powder, adding water and stirring uniformly to obtain the gangue masonry mortar.

10. The method for preparing the gangue masonry mortar according to claim 9, wherein the solid-liquid mass ratio of the powder to the water is 1: (0.1-1).