Cement coal gasification slag water-stable layer mix proportion method and cement coal gasification slag water-stable layer

Abstract

The invention discloses a cement coal gasification slag water-stable layer mix proportion method and a cement coal gasification slag water-stable layer, and belongs to the technical field of building materials.The design method comprises the following steps that the raw material mix proportion and the optimal water content of the water-stable layer are calculated on the basis of basic physical properties of coal gasification slag; the relationship between the optimal water content and the maximum dry density is explored; establishing an initial water consumption calculation model based on the relationship between the optimal water content and the maximum dry density; and based on the initial water consumption calculation model, optimizing the optimal mixing amount of each raw material by adopting a strength judgment standard. The design method provided by the invention not only realizes effective utilization of the renewable resource of the coal gasification slag and converts the coal gasification slag into the building material, but also makes a positive contribution in the aspect of environmental protection, and effectively relieves the environmental pressure.

Description

Technical Field

[0001] The present invention belongs to the technical field of building materials, and particularly relates to a method for the mix proportion of a cement gasification slag water-stable layer and a cement gasification slag water-stable layer. Background Art

[0002] The wide application of gasification technology inevitably brings about the generation of a large amount of gasification slag. Therefore, it has become particularly urgent to develop a resource utilization technology that can achieve batch processing. As a by-product of the gasification process, gasification slag weakens the advantages of gasification technology as a clean technology to a certain extent. The proportion of coal chemical gasification slag in the total mass of raw coal is as high as about 20%. With the continuous increase in the production and storage of gasification slag, it not only causes serious environmental pollution problems, but also results in a great waste of land resources, and the treatment cost of gasification slag landfills is also quite high. At present, the recycling ways of gasification slag mainly include building material utilization, underground backfilling, and sustainable and stable road base construction. In view of the gradual reduction in the current exploitation amount of natural sand and gravel materials, how to efficiently utilize gasification slag aggregates as resources has become increasingly important.

[0003] Inside the gasifier, various mineral phases in coal ash will undergo a series of complex changes with the change of temperature. By deeply studying this change process, the prior art has been able to clearly describe the physical and chemical reactions of coal ash in the gasifier, and clearly point out that coal ash has a crucial decisive influence on the final form of gasification slag. The surface of gasification slag is rough, showing various forms such as irregular spherical particles and loose flocculent aggregates, with a relatively high porosity and large pore diameters. In terms of composition, gasification slag is mainly composed of silicon dioxide, and also contains various components such as calcium oxide, magnesium oxide, and iron oxide, with stable chemical properties. Therefore, it has great potential to replace traditional materials for building material resource utilization.

[0004] Although the use of the high carbon content and rich silicon-aluminum components of gasification fine slag to prepare building materials and synthesize high-value composite materials is still in the initial stage of experimental promotion, and there is still a lack of large-scale application practice and engineering experience in high-value conversion, the existing research results undoubtedly point the way for the efficient utilization of gasification fine slag in the industrial production field. It is particularly worthy of attention that both the coarse slag and the fine slag contain a considerable amount of unburned carbon, which to a certain extent restricts their wide application as cement and concrete additives.

[0005] Therefore, how to provide a method that can directly apply gasification fine slag to building materials such as cement and concrete is a technical problem that those skilled in the art urgently need to solve. Summary of the Invention

[0006] To solve the above technical problems, the present invention provides a method for proportioning the cement gasification slag water-stable layer and the cement gasification slag water-stable layer.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for proportioning the cement gasification slag water-stable layer includes the following steps:

[0009] Based on the basic physical properties of the gasification slag, calculate the theoretical value of the raw material proportion and the optimum moisture content of the water-stable layer, and explore the relationship between the optimum moisture content and the maximum dry density;

[0010] Establish an initial water consumption calculation model based on the relationship between the optimum moisture content and the maximum dry density;

[0011] Based on the initial water consumption calculation model, optimize the optimum dosage of each raw material by using the strength judgment standard.

[0012] Preferably, the method for measuring the basic physical properties of the gasification slag includes the following steps:

[0013] Measure the mass percentages of the fine slag and the coarse slag in the gasification slag respectively, and measure the moisture contents of the fine slag and the coarse slag according to the JTG E42 standard.

[0014] Preferably, the particle size of the gasification slag is 0.075 mm - 10 mm.

[0015] More preferably, the gasification slag is composed of gasification coarse slag and gasification fine slag, the particle size of the gasification fine slag is 0.075 - 5 mm, and the particle size of the gasification coarse slag is 5 - 10 mm.

[0016] Preferably, the raw materials are a cement - gasification slag system or a cement - gasification slag - natural gravel system.

[0017] Preferably, when the raw materials are a cement - gasification slag system, the relationship between the optimum moisture content and the maximum dry density is: the optimum moisture content first increases and then decreases with the increase of the cement dosage;

[0018] When the raw materials are a cement - gasification slag - natural gravel system, the relationship between the optimum moisture content and the maximum dry density is: the optimum moisture content has a linear relationship with the natural gravel content and the gasification slag content.

[0019] Preferably, the calculation method of the initial water consumption calculation model is:

[0020] Carry out the compaction test according to the JTG E51 standard, and calculate the mass ratio of the water addition amount to the raw materials through the T0843 - 2009 standard.

[0021] Preferably, when the raw material is a cement-gasification slag system, the initial water consumption calculation model is: f(x) = -0.1429x 2 + 1.929x + 16.93; where x is the cement content / %;

[0022] Or,

[0023] When the raw material is a cement-gasification slag-natural gravel system, the initial water consumption calculation model is: f(x,y) = 15.22 - 0.144x + 0.144y; where x is the natural gravel content / %, and y is the gasification slag content / %.

[0024] Preferably, the strength judgment criterion is the 7-day unconfined compressive strength.

[0025] Preferably, when the raw material is a cement-gasification slag system, the 7-day unconfined compressive strength f(x) = 0.453x - 2.119; where x is the cement content / %;

[0026] Or,

[0027] When the raw material is a cement-gasification slag-natural gravel system, the 7-day unconfined compressive strength meets the requirements of the JTG / T F20 specification.

[0028] A cement-gasification slag water-stable layer obtained by a method for the mix proportion of a cement-gasification slag water-stable layer.

[0029] Preferably, it includes raw materials with the following mass fractions: cement 5-12%, gasification slag 88-95%.

[0030] Preferably, it includes raw materials with the following mass fractions: cement 10%, gasification slag 40-80%, natural gravel 0-30%, and natural fine aggregate 0-40%.

[0031] More preferably, natural gravel and natural fine aggregate are used.

[0032] More preferably, the particle size range of the natural gravel is 5 mm - 37.5 mm.

[0033] More preferably, the natural fine aggregate is loess.

[0034] Compared with the prior art, the present invention has the following advantages and technical effects:

[0035] The present invention provides a method for the mix proportion of a cement coal gasification slag water-stable layer and a corresponding water-stable layer structure. This method focuses on the core components of the strength of the cement coal gasification slag water-stable layer: cement and coal gasification slag, and may also include the auxiliary material natural gravel. In view of the relatively low strength of the coal gasification slag itself, the present invention compensates for this deficiency by increasing the incorporation ratio of cement, and ensures that the sufficient amount of cement can effectively wrap the coal gasification slag aggregate, thereby significantly enhancing the overall strength of the cement coal gasification slag water-stable layer. At the same time, the present invention introduces natural gravel as the skeleton material, which can further enhance its structural strength and ensure that the strength of the final mix proportion of the cement coal gasification slag water-stable layer meets the requirements of the current construction specifications. The design method provided by the present invention not only realizes the effective utilization of the coal gasification slag, a renewable resource, and converts it into building materials, but also makes a positive contribution to environmental protection and effectively reduces the environmental pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings constituting a part of this application are used to provide a further understanding of this application. The schematic embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation to this application. In the drawings:

[0037] Figure 1 It is a schematic diagram of the calculation steps of Embodiment 1 of the present invention;

[0038] Figure 2 It is a curve relationship diagram of the initial water consumption of the mix proportion of the cement coal gasification slag water-stable layer in the cement - coal gasification slag system in Embodiment 1 of the present invention;

[0039] Figure 3 It is a planar relationship diagram of the initial water consumption of the mix proportion of the cement coal gasification slag water-stable layer in the cement - coal gasification slag - natural gravel system in Embodiment 1 of the present invention;

[0040] Figure 4 It is a linear relationship diagram of the 7-day unconfined compressive strength and the cement content in the cement - coal gasification slag system in Embodiment 1 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0042] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0043] An embodiment of the present invention discloses a method for the mix proportion of a cement coal gasification slag water-stable layer, comprising the following steps:

[0044] Based on the basic physical properties of the coal gasification slag, calculate the theoretical value of the raw material mix proportion and the optimum moisture content of the water-stable layer, and explore the relationship between the optimum moisture content and the maximum dry density;

[0045] Establish an initial water consumption calculation model based on the relationship between the optimum moisture content and the maximum dry density;

[0046] Based on the initial water consumption calculation model, optimize the optimum dosage of each raw material by using the strength judgment standard.

[0047] In a preferred embodiment, the method for measuring the basic physical properties of the coal gasification slag comprises the following steps:

[0048] Measure the weight ratios of the fine slag and the coarse slag in the coal gasification slag respectively, and measure the moisture contents of the fine slag and the coarse slag according to the JTG E42 standard.

[0049] In a preferred embodiment, the particle size of the coal gasification slag is 0.075 mm - 10 mm.

[0050] In a more preferred embodiment, the coal gasification slag is composed of coal gasification coarse slag and coal gasification fine slag, the particle size of the coal gasification fine slag is 0.075 - 5 mm, and the particle size of the coal gasification coarse slag is 5 - 10 mm.

[0051] In a preferred embodiment, the raw materials are a cement - coal gasification slag system or a cement - coal gasification slag - natural gravel system.

[0052] In a preferred embodiment, when the raw materials are a cement - coal gasification slag system, the relationship between the optimum moisture content and the maximum dry density is: the optimum moisture content first increases and then decreases with the increase of the cement dosage;

[0053] When the raw materials are a cement - coal gasification slag - natural gravel system, the relationship between the optimum moisture content and the maximum dry density is: the optimum moisture content has a linear relationship with the natural gravel content and the coal gasification slag content.

[0054] In a preferred embodiment, the calculation method of the initial water consumption calculation model is:

[0055] Carry out a compaction test according to the JTG E51 standard, and calculate the mass ratio of the added water to the raw materials through the T0843 - 2009 standard.

[0056] In a preferred embodiment, when the raw materials are a cement - coal gasification slag system, the initial water consumption calculation model is: f(x) = -0.1429x 2 +1.929x + 16.93; where x is the cement dosage / %;

[0057] Or,

[0058] When the raw material is a cement - coal gasification slag - natural gravel system, the initial water consumption calculation model is: f(x,y) = 15.22 - 0.144x + 0.144y; where x is the content of natural gravel / %, and y is the content of coal gasification slag / %.

[0059] In a preferred embodiment, the strength judgment standard is the 7 - day unconfined compressive strength.

[0060] In a preferred embodiment, when the raw material is a cement - coal gasification slag system, the 7 - day unconfined compressive strength f(x) = 0.453x - 2.119; where x is the cement content / %.

[0061] Or,

[0062] When the raw material is a cement - coal gasification slag - natural gravel system, the 7 - day unconfined compressive strength meets the requirements of the JTG / T F20 specification.

[0063] The embodiment of the present invention also discloses a cement - coal gasification slag water - stable layer obtained by a method for the mix proportion of a cement - coal gasification slag water - stable layer.

[0064] In a preferred embodiment, it includes raw materials with the following mass fractions: cement 5 - 12%, coal gasification slag 88 - 95%.

[0065] In a preferred embodiment, it includes raw materials with the following mass fractions: cement 10%, coal gasification slag 40 - 80%, natural gravel 0 - 30%, and natural fine aggregate 0 - 40%.

[0066] In a more preferred embodiment, natural gravel and natural fine aggregate are adopted.

[0067] In a more preferred embodiment, the particle size range of the natural gravel is 5mm - 37.5mm.

[0068] Unless otherwise specified, the raw materials in the embodiments of the present invention are all obtained through commercial channels;

[0069] Among them, the cement is P·O·42.5 ordinary Portland cement;

[0070] The natural gravel and natural fine aggregate are purchased from Urumqi Hualing Market.

[0071] Unless otherwise specified, the room temperature or normal temperature in the embodiments of the present invention both refer to 25 ± 3°C.

[0072] Example 1

[0073] A method for the mix proportion of a cement coal gasification slag water stable layer, wherein the raw materials of the cement coal gasification slag water stable layer are cement and coal gasification slag.

[0074] The coal gasification slag consists of coal gasification coarse slag and coal gasification fine slag. Among them, the particle size of the coal gasification fine slag is 0.075 - 5 mm, and the particle size of the coal gasification coarse slag is 5 - 10 mm.

[0075] The mix proportion design method of the cement coal gasification slag water stable layer includes the following steps:

[0076] (1) Measure the mass percentages of the coal gasification fine slag and the coal gasification coarse slag in the coal gasification slag, as well as the water contents of the coal gasification fine slag and the coal gasification coarse slag.

[0077] Among them, the measurement method of the water contents of the coal gasification fine slag and the coal gasification coarse slag refers to the standard "Test Regulations for Aggregates in Highway Engineering JTG E42".

[0078] In the coal gasification slag of this embodiment, the mass percentage of the coarse slag is 15.8%, the water content is 7.43%, the mass percentage of the fine slag is 84.2%, and the water content is 12.78%.

[0079] (2) Calculate the dosages of the coal gasification slag and cement based on the mass percentages and water contents of the coal gasification fine slag and the coal gasification coarse slag. At the same time, in combination with the "Test Regulations for Inorganic Binder Stabilized Materials in Highway Engineering JTG E51", measure the optimum water content, the maximum dry density of the cement coal gasification slag water stable layer and the relationship between them. Specifically: as the cement dosage increases, the optimum water content shows a trend of first increasing and then decreasing; as the coal gasification slag dosage increases, the optimum water content shows a gradually increasing trend.

[0080] (3) Calculate the water addition amount and the mass of the inorganic binder according to the compaction test results and the mix proportion of the inorganic binder according to the standard T0843 - 2009. Specifically: the optimum water content (initial water consumption) is f(x)= - 0.1429x 2 +1.929x + 16.93, where x is the maximum dry density (cement dosage) / %, and the curve graph is as Figure 2 shown.

[0081] (4) Based on the maximum dry density and the optimum water content of the cement coal gasification slag mix proportion, the specimens are made according to the "Test Regulations for Inorganic Binder Stabilized Materials in Highway Engineering JTG E51", and are statically formed by a press. The press meets the standards in the current "Hydraulic Press GB / T 3722" and "General Technical Requirements for Testing Machines GB - T2611", and the 7 - day unconfined compressive strength test results are used as the main judgment index for determining the optimum dosages of each mix proportion.

[0082] When the mix ratio is only cement and coal gasification slag, the 7-day unconfined compressive strength f(x) has a linear relationship with the cement content x, that is, f(x) = 0.453x - 2.119, where x is the cement content / %, and the linear relationship diagram is as Figure 4 shown.

[0083] The design mix ratio of the cement coal gasification slag water-stable layer in this embodiment, and the optimum moisture content of each mix ratio and the 7-day unconfined compressive strength of each mix ratio obtained by the above calculation method are shown in Table 1:

[0084] Table 1

[0085]

[0086] Example 2

[0087] A method for the mix ratio of a cement coal gasification slag water-stable layer, wherein the mix ratio of the cement coal gasification slag water-stable layer includes cement, coal gasification slag, natural gravel, natural fine aggregate, and water.

[0088] The coal gasification slag is composed of coal gasification coarse slag and coal gasification fine slag. Among them, the particle size of the coal gasification fine slag is 0.075 - 5 mm, and the particle size of the coal gasification coarse slag is 5 - 10 mm.

[0089] The design method for the mix ratio of the cement coal gasification slag water-stable layer includes the following steps:

[0090] (1) Determine the mass percentages of the coal gasification fine slag and the coal gasification coarse slag in the coal gasification slag, as well as the moisture contents of the coal gasification fine slag and the coal gasification coarse slag.

[0091] Among them, the method for measuring the moisture contents of the coal gasification fine slag and the coal gasification coarse slag refers to the standard "Test Regulations for Highway Engineering Aggregates JTG E42".

[0092] In the coal gasification slag of this embodiment, the mass percentage of the coarse slag is 15.8%, the moisture content is 7.43%, the mass percentage of the fine slag is 84.2%, and the moisture content is 12.78%.

[0093] (2) Calculate the coal gasification slag and cement dosage based on the mass percentages and moisture contents of the coal gasification fine slag and the coal gasification coarse slag. At the same time, in combination with the "Test Regulations for Inorganic Binding Material Stabilized Materials in Highway Engineering JTG E51", determine the optimum moisture content and the maximum dry density of the cement coal gasification slag water-stable layer and the relationship between the two. Specifically: when the cement content is 10%, the optimum moisture content has a linear relationship with the natural gravel content and the coal gasification slag content, and the optimum moisture content shows a gradually increasing trend with the increase of the coal gasification slag content and the decrease of the natural gravel content.

[0094] (3) According to the compaction test results and the mix ratio of inorganic binders, calculate the water addition amount and the mass of inorganic binders in accordance with Standard T0843-2009. Specifically, the optimum moisture content (initial water consumption) is f(x,y) = 15.22 - 0.144x + 0.144y, where x is the content of natural gravel / %, and y is the content of coal gasification slag / %. The plan view is as shown in Figure 3 shown;

[0095] (4) Based on the maximum dry density and the optimum moisture content of the cement coal gasification slag mix ratio, and in accordance with "Technical Rules for Construction of Highway Pavement Base Course JTGT F20", use the 7-day unconfined compressive strength test results as the main judgment index for determining the optimum dosage of each mix ratio.

[0096] Specifically, the specimen preparation is carried out according to "Test Regulations for Inorganic Binder Stabilized Materials in Highway Engineering JTG E51", and is statically formed by a press. The press complies with the standards in the current "Hydraulic Press GB / T 3722" and "General Technical Requirements for Testing Machines GB-T2611".

[0097] When the mix ratio is only cement and coal gasification slag, the 7-day unconfined compressive strength f(x) has a linear relationship with the cement dosage x, that is, f(x) = 0.453x - 2.119, where x is the cement dosage / %. The linear relationship diagram is as shown in Figure 4 shown. When the water-stable layer mix ratio is cement, coal gasification slag and natural gravel, the 7-day unconfined compressive strength can meet the relevant requirements.

[0098] When using natural fine aggregate (loess), the designed mix ratio of the cement coal gasification slag water-stable layer in this embodiment, as well as the optimum moisture content of each mix ratio and the 7-day unconfined compressive strength of each mix ratio obtained by the above calculation method are shown in Table 2:

[0099] Table 2

[0100]

[0101] When using natural gravel, on the basis of the above test results, optimize. The designed mix ratio of the cement coal gasification slag water-stable layer in this embodiment, as well as the optimum moisture content of each mix ratio and the 7-day unconfined compressive strength of each mix ratio obtained by the above calculation method are shown in Table 3:

[0102] Table 3

[0103]

[0104] Technical effects:

[0105] As can be seen from Table 1-3, the 7-day unconfined compressive strength of the water-stabilized layer obtained from the mix proportions of the cement gasification slag water-stabilized layers numbered 8, 9, 13, and 14 is the best. On this basis, numbers 9 and 14 were selected for the paving of the test section, which meets the relevant technical index requirements of the urban road base in CJJ169 and can be used as building materials for urban roads, etc. The relevant test indexes of the water-stabilized layer obtained from number 14 are shown in Table 4:

[0106] Table 4

[0107]

[0108] The above is only the preferred specific implementation mode of this application, but the protection scope of this application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in this application should be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

1. A method for the mix proportion of a cement gasification slag water-stable layer, characterized in that, It includes the following steps: Based on the basic physical properties of coal gasification slag, calculate the theoretical value of the raw material mix ratio and the optimum moisture content of the water-stable layer, and explore the relationship between the optimum moisture content and the maximum dry density; Establish an initial water consumption calculation model based on the relationship between the optimum moisture content and the maximum dry density; Based on the initial water consumption calculation model, and optimize the optimum dosage of each raw material by using the strength judgment standard.

2. A method for the mix proportion of a cement coal gasification slag water-stable layer according to claim 1, characterized in that, The raw materials are a cement-coal gasification slag system or a cement-coal gasification slag-natural gravel system.

3. A method for the mix proportion of a cement coal gasification slag water-stable layer according to claim 1 or 2, characterized in that, When the raw material is a cement-coal gasification slag system, the relationship between the optimum moisture content and the maximum dry density is: the optimum moisture content first increases and then decreases with the cement dosage; Or, When the raw material is a cement-coal gasification slag-natural gravel system, the relationship between the optimum moisture content and the maximum dry density is: the optimum moisture content has a linear relationship with the natural gravel content and the coal gasification slag content.

4. A method for the mix proportion of a cement coal gasification slag water-stabilized layer according to claim 1 or 3, characterized in that The calculation method of the initial water consumption calculation model is: Carry out a compaction test in accordance with the JTG E51 standard, and calculate the mass ratio of the water addition amount to the raw materials through the T0843-2009 standard.

5. A method for the mix proportion of a cement coal gasification slag water-stable layer according to claim 1 or 3, characterized in that, When the raw material is a cement - coal gasification slag system, the initial water consumption calculation model is: f(x) = -0.1429x 2 + 1.929x + 16.93; where x is the cement content / %; Or, When the raw material is a cement-coal gasification slag-natural gravel system, the initial water consumption calculation model is: f(x,y)=15.22 - 0.144x + 0.144y; where x is the natural gravel content / %, and y is the coal gasification slag content / %.

6. A method for the mix proportion of a cement coal gasification slag water-stable layer according to claim 1, characterized in that, The strength judgment standard is the 7-day unconfined compressive strength.

7. A method for the mix proportion of a cement coal gasification slag water-stable layer according to claim 2 or 6, characterized in that, When the raw material is a cement-coal gasification slag system, the 7-day unconfined compressive strength f(x)=0.453x - 2.119; where x is the cement dosage / %; Or, When the raw material is a cement-coal gasification slag-natural gravel system, the 7-day unconfined compressive strength meets the requirements of the JTG / T F20 specification.

8. A cement gasification slag water-stable layer, characterized in that, Determine the raw material dosage by using the method for the mix ratio of the cement coal gasification slag water-stable layer according to any one of claims 1-7.

9. A cement gasification slag water stable layer according to claim 8, characterized in that It includes raw materials with the following mass fractions: 5-12% of cement, and 88-95% of coal gasification slag.

10. A cement gasification slag water-stable layer according to claim 8, characterized in that It includes raw materials with the following mass fractions: 10% of cement, 40-80% of coal gasification slag, 0-30% of natural gravel, and 0-40% of natural fine aggregate.

Images