Waste refractory material recycling process

Abstract

The invention provides a waste refractory material recycling process which comprises the following steps: S1, collecting a plurality of waste refractory materials from sources such as a waste refractory material storage yard and a thermal power plant, and classifying according to characteristics such as components, types and performances of the materials; s2, crushing the classified waste refractory materials by adopting a jaw crusher, a cone crusher or an impact crusher according to different materials and different properties, then grinding and grading by adopting a ball mill or a Raymond mill, and directly crushing and grading the fly ash solid waste by adopting an advanced ball milling technology provided with a double-layer screening bin separation plate and an activation lining; s3, for impurity components in the solid waste subjected to crushing treatment, performing magnetic separation, and performing immersion cleaning with an acid-base solution to remove impurities; and S4, adding an active additive and a pore-forming agent into the material obtained in S3, uniformly mixing, and then sequentially performing drying, high-temperature calcination, crushing and grading post-treatment, performance detection and product warehousing. According to the invention, the adverse effects of waste discharge and over-mining of natural mineral resources on the ecological environment are effectively reduced.

Description

Technical Field

[0001] The invention relates to the technical field of solid waste recycling, and in particular to a process for recycling waste refractory materials. Background Art

[0002] As an important energy-saving material in the construction and industrial fields, inorganic lightweight thermal insulation materials have excellent thermal insulation performance, low density, good fire resistance and high temperature resistance, and are widely used in thermal insulation of walls, roofs, thermal pipes and furnaces. Especially in recent years, with the intensification of the global energy crisis and the promotion of environmental protection policies, the research and development of inorganic lightweight thermal insulation materials has received increasing attention.

[0003] Lightweight thermal insulation materials were first proposed and developed rapidly by some developed countries in the United States and Western Europe. Their main features include low bulk density, high porosity, and low thermal conductivity. These characteristics enable them to effectively block the transfer of heat, thereby improving thermal energy utilization and reducing heat loss, or reducing the temperature rise of buildings caused by solar radiation and saving refrigeration energy consumption, becoming an important means of energy conservation and emission reduction. There are many types of lightweight thermal insulation materials, which can be divided into two categories: inorganic and organic according to their material composition. Among them, inorganic thermal insulation materials are not only resistant to high temperatures, have good thermal stability and thermal insulation, but also have outstanding advantages such as stable performance (fire retardant, small deformation coefficient, anti-aging, strong durability), safety and environmental protection, economy and wide range of applications, becoming the focus of current research and development. Commonly used lightweight insulation materials mainly include expanded perlite, ceramic fiber, aerogel, rock wool, mineral wool, glass wool, calcium silicate, foam or aerated concrete, and aluminum silicate lightweight thermal insulation refractory materials.

[0004] With the rapid development of my country's economy and the accelerated advancement of urbanization, the generation of inorganic solid waste (such as industrial waste residue, tailings, waste products, construction waste, etc.) has increased dramatically, bringing tremendous pressure to the environment. The resource utilization of solid waste is one of the important means for my country to implement the sustainable development strategy. Faced with the severe situation of tightening resource constraints and serious environmental pollution, it is particularly urgent and important to promote the high-value utilization of solid waste resources.

[0005] The main components of waste refractory solid waste are SiO2, Al2O3 and MgO, etc. Therefore, they have great potential for resource utilization in the production of inorganic non-metallic materials and products, and are expected to save a lot of natural mineral resources and reduce product costs, thereby creating huge economic and ecological benefits. In recent years, a lot of research has been carried out at home and abroad on the resource utilization of refractory and fly ash solid waste. Among them, refractory solid waste is mainly reused in the preparation of refractory or castables after crushing, sorting and purification, while fly ash is mainly used in the preparation of concrete and cement admixtures. However, due to the limitations of the production process and product performance of solid waste recycling products, there are generally bottleneck problems such as low effective utilization rate of solid waste, low added value, high cost, and narrow product application field, which seriously restricts the large-scale industrial utilization of refractory solid waste, resulting in a large waste of resources, and a large amount of solid waste accumulation causes serious environmental pollution problems. Therefore, it is necessary to design and improve the relevant technologies. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention provides a process for recycling and reusing waste refractory materials.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0008] A waste refractory material recycling process comprises the following steps:

[0009] S1. Collect various waste refractory materials from waste refractory material yards, thermal power plants and other sources, and classify them according to the composition, type, performance and other characteristics of the materials;

[0010] S2. The classified waste refractory materials are crushed by jaw crusher, cone crusher or impact crusher according to their materials and properties, and then ground and graded by ball mill or Raymond mill. The fly ash solid waste is directly crushed and graded by advanced ball milling technology equipped with double-layer screen partition plates and activated lining;

[0011] S3. For the impurities in the solid waste after pulverization, magnetic separation and acid-base solution washing are used to remove impurities;

[0012] S4, adding active additives and pore-forming agents to the material obtained in S3, mixing evenly, and then sequentially drying, high-temperature calcination, crushing and grading, post-processing, performance testing, and product storage.

[0013] Preferably, in step S1, one or more of X-ray fluorescence spectrometer, X-ray energy dispersion spectroscopy, and chemical analysis are used to perform component analysis on the raw material to determine the content of each component; and the microscopic morphology and structural characteristics of the raw material are observed by scanning electron microscopy or transmission electron microscopy.

[0014] Preferably, in step S4, the active additive contains spodumene and bentonite.

[0015] Preferably, in step S4, the active additive further contains a high-activity aluminum source, a high-activity silicon source or a high-activity magnesium source.

[0016] Preferably, in step S4, the pore-forming agent is one or more of polystyrene microspheres, wood chips, anthracite ash, starch or carbonate.

[0017] Preferably, in step S4, the obtained product is a mullite or cordierite lightweight thermal insulation powder material.

[0018] Preferably, in step S4, the product reaction process is optimized by analyzing the microscopic morphology of the powder by SEM or TEM, analyzing the powder particle size distribution and specific surface area by a laser particle size analyzer and a BET specific surface area method, determining the powder apparent density by a loose density measuring device, determining the thermal conductivity of the powder material by a hot plate method or a specific heat method, determining the infrared emissivity of the material by an infrared thermal imager method and an integrating sphere method, characterizing the thermal expansion coefficient of the material by a linear thermal expansion meter, and determining the mass change, phase composition and chemical composition change, and microscopic morphology change of the powder material after corrosion by acid and alkali solutions.

[0019] Preferably, in step S3, after magnetic separation, flotation reagent is added and air is introduced for flotation.

[0020] The beneficial effects of the present invention are:

[0021] In the present invention, the solid waste utilization rate of waste refractory materials and fly ash is significantly improved, which can reach more than 95%, and the consumption of natural mineral resources such as bauxite, kaolin, quartz, dolomite, periclase, olivine, etc. is correspondingly reduced, and the adverse effects of waste discharge and excessive exploitation of natural mineral resources on the ecological environment are effectively reduced.

[0022] The present invention lays a prerequisite foundation for the large-scale resource and high-value utilization of solid waste by developing an efficient, low-cost, and environmentally friendly refractory solid waste pretreatment technology.

[0023] The present invention aims to realize the efficient resource utilization of various waste refractory materials and solid wastes such as fly ash and prepare light-weight thermal insulation powder materials of mullite or cordierite with excellent performance, so as to provide new energy-saving material support for high-temperature industry and many other thermal insulation fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a flow chart for the recycling of waste refractory materials in the present invention;

[0025] Figure 2 This is the production process of the lightweight thermal insulation powder material in the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Embodiment 1:

[0028] A process for recycling and reusing waste refractory materials comprises the following steps:.

[0029] S1. Collect various waste refractory materials from waste refractory material yards, thermal power plants and other sources, and classify them according to the composition, type, performance and other characteristics of the materials;

[0030] Among them, one or more of X-ray fluorescence spectrometer (XRF), X-ray energy dispersive spectroscopy (EDX), and chemical analysis are used to analyze the composition of the raw materials to determine the content of each component, especially the proportion of key components such as Al2O3, SiO2 and MgO and the content of harmful components such as Cr and Fe; the microscopic morphology and structural characteristics of the raw materials are observed by scanning electron microscopy (SEM) or transmission electron microscopy (TEM);

[0031] S2. The classified waste refractory materials are crushed by jaw crusher, cone crusher or impact crusher according to their materials and properties, and then ground and graded by ball mill or Raymond mill. The fly ash solid waste is directly crushed and graded by advanced ball milling technology equipped with double-layer screen partition plates and activated lining;

[0032] S3. For the impurities in the solid waste after pulverization, magnetic separation and acid-base solution washing are used to remove impurities;

[0033] S4, adding active additives and pore-forming agents to the material obtained in S3, mixing evenly, and then drying, high-temperature calcination, crushing and grading post-processing, performance testing, and product storage (the obtained product is mullite or cordierite lightweight thermal insulation powder material);

[0034] The active additives include spodumene and bentonite, and the pore-forming agent is one or more of polystyrene microspheres, sawdust, anthracite ash, starch or carbonate;

[0035] The product reaction process is optimized by analyzing the microscopic morphology of the powder by SEM or TEM, analyzing the particle size distribution and specific surface area of ​​the powder by laser particle size analyzer and BET specific surface area method, determining the apparent density of the powder by loose density measuring device, determining the thermal conductivity of the powder material by hot plate method or specific heat method, determining the infrared emissivity of the material by infrared thermal imager method and integrating sphere method, characterizing the thermal expansion coefficient of the material by linear thermal expansion meter, and comprehensively analyzing the chemical stability of the powder material by the mass change, phase composition and chemical composition change and microscopic morphology change after corrosion by acid and alkali solution.

[0036] Based on the above research, the production process was determined, a production line was established, and pilot and production tests were carried out to prepare lightweight thermal insulation powder materials from multiple solid wastes. Ultimately, stable industrial production was achieved, and product application and promotion were carried out.

[0037] Embodiment 2:

[0038] A process for recycling and reusing waste refractory materials. The difference between this embodiment and embodiment 1 is that: in step S3, after magnetic separation, flotation agents are added and air is introduced for flotation to form countless tiny bubbles, so that particles of the desired material adhere to the bubbles and float with the bubbles, thereby achieving effective separation of solid wastes, and then impurity removal treatment is carried out by immersion in acid and alkali solutions.

[0039] Embodiment 3:

[0040] A process for recycling and reusing waste refractory materials. The difference between this embodiment and embodiment 2 is only that: in step S4, the active additive also contains a high-activity aluminum source, a high-activity silicon source or a high-activity magnesium source.

[0041] Comparative Example 1:

[0042] A process for recycling and reusing waste refractory materials. The difference between this comparative example and Example 3 is that spodumene is not added to the active additive.

[0043] Comparative Example 2:

[0044] A process for recycling and reusing waste refractory materials. The difference between this comparative example and Example 3 is that bentonite is not added to the active additive.

[0045] Comparative Example 3:

[0046] A process for recycling and reusing waste refractory materials. The difference between this comparative example and Example 3 is that no high-activity aluminum source, high-activity silicon source or high-activity magnesium source is added to the active additive.

[0047] Comparative Example 4:

[0048] A process for recycling and reusing waste refractory materials. The difference between this comparative example and Example 3 is that no pore-forming agent is added.

[0049] Comparative Example 5:

[0050] A process for recycling and reusing waste refractory materials. The difference between this comparative example and Example 3 is that no flotation agent is added and air is introduced for flotation.

[0051] The solid waste utilization rate of the waste refractory solid waste recycling processes in the above Examples 1-3 and Comparative Examples 1-5 was tested, and the measured data are shown in Table 1.

[0052] Table 1 Results of solid waste utilization of waste refractory materials obtained in Examples 1-3 and Comparative Examples 1-5

[0053]

[0054] From Table 1, we can see that:

[0055] The utilization rate of waste refractory materials and fly ash solid waste is significantly improved, reaching more than 95%, which correspondingly reduces the consumption of natural mineral resources such as bauxite, kaolin, quartz, dolomite, periclase, olivine, etc., and effectively reduces the adverse effects of waste discharge and excessive exploitation of natural mineral resources on the ecological environment. The present invention lays a prerequisite for the large-scale resource utilization and high-value utilization of solid waste by developing an efficient, low-cost, and environmentally friendly refractory solid waste pretreatment technology.

[0056] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A process for recycling and reusing waste refractory materials, characterized in that: The following steps are included: S1. Collect various waste refractory materials from waste refractory material yards, thermal power plants and other sources, and classify them according to the composition, type, performance and other characteristics of the materials; S2. The classified waste refractory materials are crushed by jaw crusher, cone crusher or impact crusher according to their materials and properties, and then ground and graded by ball mill or Raymond mill. The fly ash solid waste is directly crushed and graded by advanced ball milling technology equipped with double-layer screen partition plates and activated lining; S3. For the impurities in the solid waste after pulverization, magnetic separation and acid-base solution washing are used to remove impurities; S4, adding active additives and pore-forming agents to the material obtained in S3, mixing evenly, and then sequentially drying, high-temperature calcination, crushing and grading, post-processing, performance testing, and product storage.

2. The solid waste recycling process of waste refractory materials according to claim 1 is characterized in that: In step S1, one or more of X-ray fluorescence spectrometer, X-ray energy dispersion spectroscopy, and chemical analysis are used to analyze the raw materials to determine the content of each component; the microscopic morphology and structural characteristics of the raw materials are observed by scanning electron microscopy or transmission electron microscopy.

3. The solid waste recycling process of waste refractory materials according to claim 2 is characterized in that: In step S4, the active additive contains spodumene and bentonite.

4. The solid waste recycling process of waste refractory materials according to claim 3 is characterized in that: In step S4, the active additive further contains a high-activity aluminum source, a high-activity silicon source or a high-activity magnesium source.

5. The solid waste recycling process of waste refractory materials according to claim 4 is characterized in that: In step S4, the pore-forming agent is one or more of polystyrene microspheres, wood chips, anthracite ash, starch or carbonate.

6. The solid waste recycling process of waste refractory materials according to claim 5 is characterized in that: In step S4, the obtained product is a mullite or cordierite lightweight thermal insulation powder material.

7. The solid waste recycling process of waste refractory materials according to claim 5 is characterized in that: In step S4, the product reaction process is optimized by analyzing the microscopic morphology of the powder based on SEM or TEM, analyzing the powder particle size distribution and specific surface area by laser particle size analyzer and BET specific surface area method, determining the powder apparent density by loose density measuring device, determining the thermal conductivity of the powder material by hot plate method or specific heat method, determining the infrared emissivity of the material by infrared thermal imager method and integrating sphere method, characterizing the thermal expansion coefficient of the material by linear thermal expansion meter, and measuring the mass change, phase composition and chemical composition change and microscopic morphology change of the powder material after corrosion by acid and alkali solution.

8. The solid waste recycling process of waste refractory materials according to claim 2 is characterized in that: In step S3, after magnetic separation, flotation reagents are added and air is introduced for flotation.

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