Ceramic material and preparation method thereof

Abstract

The invention belongs to the technical field of solid waste recycling, and particularly relates to a ceramic material and a preparation method thereof. The ceramic material comprises the following raw materials: coal gasification slag, clay and an inert heat storage medium material. The preparation method of the ceramic material has the beneficial effects that inorganic components in the coal gasification slag are changed into high-value ceramsite products, the organic components provide heat required by reaction and simultaneously prepare CO raw material gas required by chemical engineering, and the utilization way of the coal gasification slag is widened.

Description

Technical Field

[0001] This application belongs to the field of solid waste recycling technology, specifically relating to a ceramic material and its preparation method. Background Technology

[0002] Coal gasification technology, as one of the important means of clean coal utilization, is a core technology for efficient coal utilization. Coal gasification slag is the solid residue after coal is burned and gasified in a gasifier. Due to its high carbon content, coal gasification slag cannot be directly used in cement and concrete. In addition, although coal gasification slag has a certain calorific value, its high moisture content, numerous impurities, and low carbon content do not meet the combustion requirements of boilers, and therefore it cannot be directly used for large-scale co-firing. Summary of the Invention

[0003] This application provides a ceramic material and its preparation method, aiming to solve the problem of high-value utilization of coal gasification slag. The method described in this application transforms the inorganic components in coal gasification slag into high-value ceramsite products, while the organic components provide the heat required for the reaction and simultaneously produce CO feed gas required for chemical production, thus broadening the utilization pathways of coal gasification slag.

[0004] The first aspect of this application provides a ceramic material comprising the following raw materials: coal gasification slag, clay, and an inert heat storage medium.

[0005] According to some embodiments of the ceramic material described in this application, the mass ratio of the coal gasification slag to the inert heat storage medium material is 1:(1-5).

[0006] According to some embodiments of the ceramic material described in this application, the total amount of the coal gasification slag and the inert heat storage medium material is in a mass ratio of 100:(20-50) to the clay.

[0007] According to some embodiments of the ceramic material described in this application, the inert heat storage medium material includes quartz sand.

[0008] According to some embodiments of the ceramic material described in this application, the coal gasification slag includes coarse coal gasification slag and fine coal gasification slag.

[0009] According to some embodiments of the ceramic material described in this application, the coal gasification slag includes coarse coal gasification slag and fine coal gasification slag in a mass ratio of (1-5):1.

[0010] A second aspect of this application provides a method for preparing the ceramic material described in the first aspect of this application, comprising the following steps:

[0011] Under the action of gasifying agent and combustion aid, coal gasification slag, inert heat storage medium material and clay are mixed and subjected to smoldering treatment.

[0012] According to some embodiments of the method for preparing the ceramic material described in this application, the gasifying agent includes carbon dioxide.

[0013] According to some embodiments of the method for preparing the ceramic material described in this application, the combustion aid includes air.

[0014] According to some embodiments of the method for preparing ceramic materials described in this application, the Darcy rate of the gas-gas mixture of gasifying agent and combustion aid is V;

[0015] V = Q / A, where Q is the gas flow rate through the smoldering combustion chamber, in cm³. 3 / s; A is the cross-sectional area of ​​the smoldering combustion chamber, in cm². 2 .

[0016] According to some embodiments of the method for preparing ceramic materials described in this application, the Darcy rate of the gasified agent and combustion aid mixture is 2-10 cm / s.

[0017] According to some embodiments of the method for preparing the ceramic material described in this application, the volume ratio of the gasifying agent to the combustion aid is 1:(1-5).

[0018] According to some embodiments of the method for preparing ceramic materials described in this application, the smoldering temperature is 900-1300℃ and the smoldering time is 1-4h.

[0019] According to some embodiments of the method for preparing ceramic materials described in this application, the smoldering temperature is 1000-1200℃, and the smoldering time is 1-4h.

[0020] The beneficial effects of this application include: the method for preparing ceramic materials described in this application transforms the inorganic components in coal gasification slag into high-value ceramsite products, while the organic components provide the heat required for the reaction and simultaneously produce CO feedstock gas required for chemical processing, thus broadening the utilization pathways of coal gasification slag. Detailed Implementation

[0021] The embodiments of the present invention are described in detail below. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0022] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0023] This application provides a ceramic material comprising the following raw materials: coal gasification slag, clay, and an inert heat storage medium. The clay in the ceramic material possesses good plasticity and binding properties, enabling it to bond tightly with other materials and form robust ceramsite after sintering. The coal gasification slag and the inert heat storage medium are primarily composed of silicates, which can react at high temperatures to serve as raw materials for ceramsite preparation. The preparation method of the ceramic material described in this application transforms the inorganic components of the gasification slag into high-value ceramsite products, while the organic components provide the heat required for the reaction and simultaneously produce CO feedstock gas needed for chemical processing, thus broadening the utilization pathways of coal gasification slag.

[0024] In some embodiments of this application, the mass ratio of the coal gasification slag to the inert heat storage medium material is 1:(1-5), for example 1:1, 1:2, 1:3, 1:5, etc.

[0025] In some embodiments of this application, the total amount of the coal gasification slag and the inert heat storage medium material is in a mass ratio of 100:(20-50) to the clay, for example, 100:20, 100:25, 100:37, 100:43, 100:50, etc.

[0026] If the clay addition ratio is too small, the molding effect will be poor, and the clay will stick together in clumps, which is not conducive to continuous operation in subsequent engineering production and poses a risk of difficulty in slag removal. In addition, the clay addition ratio should not be too high in order to reduce costs.

[0027] In some embodiments of this application, the inert heat storage medium material includes quartz sand.

[0028] In some embodiments of this application, the coal gasification slag includes coarse coal gasification slag and fine coal gasification slag.

[0029] In some embodiments of this application, the coal gasification slag includes coarse coal gasification slag and fine coal gasification slag in a mass ratio of (1-5):1. There are few ways to utilize the high-value coal gasification slag. The higher the proportion of coarse slag added, the lower the cost. However, the coarse slag has a large particle size, and if the proportion added is high, it is easy to stick and clump together during firing, making it impossible to form.

[0030] This application also provides a method for preparing the ceramic material described in the first aspect of this application, comprising the following steps: mixing coal gasification slag, inert heat storage medium material and clay under the action of a gasifying agent and a combustion aid for smoldering treatment.

[0031] In some embodiments of this application, the vaporizing agent includes carbon dioxide.

[0032] In some embodiments of this application, the combustion accelerant includes air.

[0033] In some embodiments of this application, the Darcy rate of the gas mixture of gasifying agent and combustion improver is V; V = Q / A, where Q is the gas flow rate through the smoldering combustion chamber, in cm³. 3 / s; A is the cross-sectional area of ​​the smoldering combustion chamber, in cm². 2 .

[0034] In some embodiments of this application, the Darcy rate of the gas mixture of gasifying agent and combustion accelerant is 2-10 cm / s, such as 2 cm / s, 3 cm / s, 5 cm / s, 7 cm / s, 10 cm / s, etc.

[0035] In some embodiments of this application, the volume ratio of the gasifying agent to the combustion aid is 1:(1-5); for example, 1:1, 1:2, 1:3, 1:5, etc. The ceramsite firing process requires maintaining a high-temperature environment, and the combustion aid can provide the atmosphere of the high-temperature environment. However, if the proportion of the combustion aid is too high, the temperature will be too high, causing the material to melt and preventing normal operation. Adding a gasifying agent can maintain a stable reaction temperature and produce CO syngas, which is beneficial to the overall economic efficiency of the project.

[0036] In some embodiments of this application, the smoldering temperature is 900-1300℃, such as 900℃, 1000℃, 1100℃, 1200℃, 1300℃, etc., and the smoldering time is 1-4h, such as 1h, 2h, 3h, 4h, etc.

[0037] In some embodiments of this application, the smoldering temperature is 1000-1200℃, such as 1000℃, 1100℃, 1200℃, etc., and the smoldering time is 1-4h, such as 1h, 2h, 3h, 4h, etc.

[0038] The technical solution of this application will be further described below with reference to specific embodiments.

[0039] Example 1

[0040] A method for preparing a ceramic material includes the following steps:

[0041] The gasification slag (containing coarse and fine gasification slag in a 1:1 mass ratio), inert heat storage medium quartz sand, and clay were mixed and placed in a smoldering chamber. The mass ratio of gasification slag to inert heat storage medium quartz sand was 1:1, and the total mass ratio of gasification slag and inert heat storage medium quartz sand to clay was 100:30. A mixture of carbon dioxide and air in a 1:3 volume ratio was introduced into the smoldering chamber, and the Darcy velocity of the mixture was controlled at 5 cm / s. The mixture was smoldered at 1000℃ for 3 hours.

[0042] Example 2

[0043] The only difference between the ceramic material preparation method described in Example 2 and that in Example 1 is that the total amount of coal gasification slag and inert heat storage medium material and the mass ratio of clay in the ceramic material preparation process in Example 2 is 100:20.

[0044] The specific operating steps include:

[0045] The gasification slag (containing coarse and fine gasification slag in a 1:1 mass ratio), inert heat storage medium quartz sand, and clay were mixed and placed in a smoldering chamber. The mass ratio of gasification slag to inert heat storage medium quartz sand was 1:1, and the total mass ratio of gasification slag and inert heat storage medium quartz sand to clay was 100:20. A mixture of carbon dioxide and air in a 1:3 volume ratio was introduced into the smoldering chamber, and the Darcy velocity of the mixture was controlled at 5 cm / s. The mixture was smoldered at 1000℃ for 3 hours.

[0046] Example 3

[0047] The only difference between the preparation method of the ceramic material in Example 3 and that in Example 1 is that the total amount of coal gasification slag and inert heat storage medium material and the mass ratio of clay in the preparation process of the ceramic material in Example 3 is 100:40.

[0048] The specific operating steps include:

[0049] The gasification slag (containing coarse and fine gasification slag in a 1:1 mass ratio), inert heat storage medium quartz sand, and clay were mixed and placed in a smoldering chamber. The mass ratio of gasification slag to inert heat storage medium quartz sand was 1:1, and the total mass ratio of gasification slag and inert heat storage medium quartz sand to clay was 100:40. A mixture of carbon dioxide and air in a 1:3 volume ratio was introduced into the smoldering chamber, and the Darcy velocity of the mixture was controlled at 5 cm / s. The mixture was smoldered at 1000℃ for 3 hours.

[0050] Example 4

[0051] The only difference between the preparation method of the ceramic material in Example 4 and that in Example 1 is that the total amount of coal gasification slag and inert heat storage medium material and the mass ratio of clay in the preparation process of the ceramic material in Example 4 is 100:50.

[0052] The specific operating steps include:

[0053] The gasification slag (containing coarse and fine gasification slag in a 1:1 mass ratio), inert heat storage medium quartz sand, and clay were mixed and placed in a smoldering chamber. The mass ratio of gasification slag to inert heat storage medium quartz sand was 1:1, and the total mass ratio of gasification slag and inert heat storage medium quartz sand to clay was 100:50. A mixture of carbon dioxide and air in a 1:3 volume ratio was introduced into the smoldering chamber, and the Darcy velocity of the mixture was controlled at 5 cm / s. The mixture was smoldered at 1000℃ for 3 hours.

[0054] Example 5

[0055] The only difference between the preparation method of the ceramic material described in Example 5 and that in Example 1 is that the volume ratio of the gasifying agent to the combustion aid in the preparation process of the ceramic material described in Example 5 is 1:2.

[0056] The specific operating steps include:

[0057] The gasification slag (containing coarse and fine gasification slag in a 1:1 mass ratio), inert heat storage medium quartz sand, and clay were mixed and placed in a smoldering chamber. The mass ratio of gasification slag to inert heat storage medium quartz sand was 1:1, and the total mass ratio of gasification slag and inert heat storage medium quartz sand to clay was 100:30. A mixture of carbon dioxide and air in a 1:2 volume ratio was introduced into the smoldering chamber, and the Darcy velocity of the mixture was controlled at 5 cm / s. The mixture was smoldered at 1000℃ for 3 hours.

[0058] Example 6

[0059] The only difference between the preparation method of the ceramic material described in Example 6 and that in Example 1 is that the volume ratio of the gasifying agent to the combustion aid in the preparation process of the ceramic material described in Example 6 is 1:4.

[0060] The specific operating steps include:

[0061] The gasification slag (containing coarse and fine gasification slag in a 1:1 mass ratio), inert heat storage medium quartz sand, and clay were mixed and placed in a smoldering chamber. The mass ratio of gasification slag to inert heat storage medium quartz sand was 1:1, and the total mass ratio of gasification slag and inert heat storage medium quartz sand to clay was 100:30. A mixture of carbon dioxide and air in a 1:4 volume ratio was introduced into the smoldering chamber, and the Darcy velocity of the mixture was controlled at 5 cm / s. The mixture was smoldered at 1000℃ for 3 hours.

[0062] Example 7

[0063] The only difference between the preparation method of the ceramic material described in Example 7 and that in Example 1 is that the volume ratio of the gasifying agent to the combustion aid in the preparation process of the ceramic material described in Example 7 is 1:5.

[0064] The specific operating steps include:

[0065] The gasification slag (containing coarse and fine gasification slag in a 1:1 mass ratio), inert heat storage medium quartz sand, and clay were mixed and placed in a smoldering chamber. The mass ratio of gasification slag to inert heat storage medium quartz sand was 1:1, and the total mass ratio of gasification slag and inert heat storage medium quartz sand to clay was 100:30. A mixture of carbon dioxide and air in a 1:5 volume ratio was introduced into the smoldering chamber, and the Darcy velocity of the mixture was controlled at 5 cm / s. The mixture was smoldered at 1000℃ for 3 hours.

[0066] Comparative Example 1

[0067] The only difference between the preparation method of the ceramic material described in Comparative Example 1 and that in Example 1 is that no gasifying agent is introduced during the preparation process of the ceramic material described in Comparative Example 1.

[0068] The specific operating steps include:

[0069] The gasification slag (containing coarse and fine gasification slag in a 1:1 mass ratio), inert heat storage medium material quartz sand, and clay were mixed and placed in a smoldering chamber. The mass ratio of gasification slag to inert heat storage medium material quartz sand was 1:1, and the total mass ratio of gasification slag and inert heat storage medium material quartz sand to clay was 100:30. Air was introduced into the smoldering chamber, and the Darcy velocity of the air was controlled at 5 cm / s. The chamber was smoldered at 1000℃ for 3 hours.

[0070] Comparative Example 2

[0071] The only difference between the preparation method of the ceramic material in Comparative Example 2 and that in Example 1 is that calcination is used instead of smoldering in the preparation process of the ceramic material in Comparative Example 2.

[0072] The specific operating steps include:

[0073] Coal gasification slag (containing coarse and fine coal gasification slag in a 1:1 mass ratio), inert heat storage medium material quartz sand, and clay are mixed and placed in a calcining furnace. The mass ratio of coal gasification slag to inert heat storage medium material quartz sand is 1:1, and the total mass ratio of coal gasification slag and inert heat storage medium material quartz sand to clay is 100:30. A mixture of carbon dioxide and air in a 1:3 volume ratio is introduced into the calcining furnace, and the Darcy velocity of the mixture is controlled at 5 cm / s. The furnace is calcined at 1000℃ for 3 hours.

[0074] Performance studies of the ceramic materials described in Examples 1-10 and Comparative Examples 1-2 of this application

[0075] Table 1

[0076]

[0077] As can be seen from Table 1:

[0078] If the clay ratio is too low, the overall calorific value of the system is high, the reaction temperature is high, and the reaction rate is fast. If the temperature is too high, the ceramsite will melt and eventually clump together, making it impossible to form. Introducing gasification gas can control the reaction temperature and increase the CO concentration.

[0079] Increased temperature will cause the expanded clay to undergo a densification reaction, transforming the amorphous kaolin and feldspar in the expanded clay into the mullite phase, thus increasing the density and strength of the expanded clay. Low-temperature produced low-strength, high-porosity expanded clay can be used for soil moisture retention and ecological restoration, while high-temperature expanded clay can be used as aggregate for roadbeds and ordinary concrete.

[0080] The technology described in this project can utilize the energy of the gasification slag itself to prepare ceramsite without the need for external heating, thus promoting energy conservation and carbon reduction.

[0081] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A ceramic material, characterized in that, It includes the following raw materials: coal gasification slag, clay, and inert heat storage medium materials.

2. The ceramic material according to claim 1, characterized in that, The mass ratio of the coal gasification slag to the inert heat storage medium material is 1:(1-5); And / or, the total amount of the coal gasification slag and the inert heat storage medium material is in a mass ratio of 100:(20-50) to the clay.

3. The ceramic material according to claim 1, characterized in that, The inert heat storage medium material includes quartz sand.

4. The ceramic material according to claim 1, characterized in that, The coal gasification slag includes coarse coal gasification slag and fine coal gasification slag; Preferably, the coal gasification slag includes coarse coal gasification slag and fine coal gasification slag in a mass ratio of (1-5):

1.

5. A method for preparing the ceramic material according to any one of claims 1-4, characterized in that, Includes the following steps: Under the action of gasifying agent and combustion aid, coal gasification slag, inert heat storage medium material and clay are mixed and subjected to smoldering treatment.

6. The method for preparing the ceramic material according to claim 5, characterized in that, The vaporizing agent includes carbon dioxide; And / or, the combustion accelerant includes air.

7. The method for preparing the ceramic material according to claim 5, characterized in that, The Darcy rate of the gas mixture of gasifying agent and combustion oxidizer is V; V = Q / A, where Q is the gas flow rate through the smoldering combustion chamber, in cm³. 3 / s; A is the cross-sectional area of ​​the smoldering combustion chamber, in cm². 2 .

8. The method for preparing the ceramic material according to claim 5, characterized in that, The Darcy velocity of the gas mixture of gasifying agent and combustion oxidizer is 2-10 cm / s; Preferably, the volume ratio of the gasifying agent to the combustion-supporting agent is 1:(1-5).

9. The method for preparing the ceramic material according to claim 5, characterized in that, The smoldering temperature is 900-1300℃, and the smoldering time is 1-4 hours.

10. The method for preparing the ceramic material according to claim 5, characterized in that, The smoldering temperature is 1000-1200℃, and the smoldering time is 1-4 hours.

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