Method for preparing brushable hydrogel to adsorb tiny particles from coal gangue

Abstract

The invention discloses a method for preparing brushable hydrogel to adsorb tiny particulate matters from coal gangue, which comprises the following steps: crushing coarse-grain-based coal gangue by a jaw crusher, calcining in a muffle furnace, and decomposing the coal gangue into active SiO and AlO3; the method comprises the following steps: leaching coal gangue for 3 hours by using hydrochloric acid, filtering to remove iron, retaining filtrate, extracting Al, then melting the calcined coal gangue and NaOH at a certain temperature for 1 hour, and leaching by using hot water to prepare a sodium silicate solution; slowly acidifying the sodium silicate solution with diluted hydrochloric acid to generate nano SiOsol, then adding a sodium polyacrylate dispersing agent into the Al solution, and stirring until the solution is transparent to obtain aluminum sol; the preparation method comprises the following steps: mixing nano SiOsol and aluminum sol according to a certain volume ratio, and adding a rheological modifier, a plasticizer and a curing agent to obtain a viscous mixed solution; because a hydrogel material is regarded as a potential solution due to a three-dimensional network structure and high adsorbability, the invention aims at the characteristics of coal gangue, and aims at realizing the dual purposes of solid waste recycling and photovoltaic cleaning and efficiency improvement.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental protection and photovoltaic panel cleaning, and particularly relates to a method for preparing brushable hydrogel for adsorbing tiny particles from coal gangue. Background Art

[0002] As one of the core technologies of clean energy, the efficiency of photovoltaic power generation is significantly affected by environmental factors. Studies have shown that dust and particulate matter (especially PM10 and PM2.5) deposited on the surface of photovoltaic panels can cause a 20%-40% decrease in light absorption. In areas with high incidence of sandstorms or industrial pollution, annual power generation losses can reach billions of dollars. Traditional cleaning methods such as mechanical scraping can easily damage the anti-reflective coating of photovoltaic panels. High-pressure water washing consumes 3-5 liters of water per square meter, which is limited in its application in arid areas. Chemical cleaning agent residues may corrode components and contaminate the soil. More importantly, the above method has a removal efficiency of less than 30% for particles with a particle size of less than 10 μm. Due to their high specific surface area and strong adsorption, these particles have become the main cause of light attenuation.

[0003] Gangue is an industrial solid waste generated during coal mining and washing, and is produced in huge quantities. Since it cannot be disposed of in a timely and large-scale manner, it can only be stored on site, which not only occupies a large amount of land, but also brings serious environmental pollution risks to the local area. Therefore, the issues of reduction, harmlessness, resource utilization and comprehensive utilization of gangue waste need to be solved urgently. Summary of the invention

[0004] In order to solve the above technical problems existing in the prior art, the present invention provides a method for preparing a brushable hydrogel for adsorbing tiny particles from coal gangue, which mainly aims at improving environmental protection and photovoltaic panel cleaning and dust removal technology, while realizing the resource utilization of coal gangue.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solution: a method for preparing brushable hydrogel for adsorbing tiny particles from coal gangue, comprising the following steps: S1. The coarse-grained coal gangue is crushed by a jaw crusher and calcined in a muffle furnace to decompose the coal gangue into active SiO2 and Al2O3; S2. First, the acid leaching method is used to extract aluminum. The coal gangue is leached with hydrochloric acid for 3 hours. After filtering and removing iron, the filtrate is retained to extract Al³⁺. Then, the alkali dissolution method is used to extract silicon. The calcined coal gangue is melted with NaOH at a certain temperature for 1 hour, and hot water is used to leaching to obtain a sodium silicate solution; S3, slowly acidify the sodium silicate solution with dilute hydrochloric acid to generate nano-SiO2 sol, then add sodium polyacrylate dispersant to the Al³⁺ solution, and stir until transparent to obtain aluminum sol; S4, silica sol and aluminum sol are mixed in a certain volume ratio, and a rheology regulator, a plasticizer and a curing agent are added to obtain a viscous mixed liquid; S5. The mixed liquid is evenly applied to the surface of the photovoltaic panel and cured under sunlight for a certain period of time to form a gel layer.

[0006] Furthermore, in step S1, the coal gangue is crushed to 100-200 mesh, the calcination temperature is 750° C., and the calcination time is 2 h.

[0007] Furthermore, in step S2, the mass ratio of coal gangue to NaOH is 1:1.

[0008] Furthermore, in step S2, the coal gangue is leached with hydrochloric acid and acidified to pH=3-4.

[0009] Furthermore, in step S3, the volume ratio of nano-SiO2 sol to aluminum sol is 7:3.

[0010] Furthermore, in step S4, the rheology regulator is hydroxyethyl cellulose (HEC), the plasticizer is glycerol, and the curing agent is a silane coupling agent (KH-550).

[0011] By adopting the above technical solution, the present invention has the following advantages and beneficial effects compared with the prior art: (1) The invention discloses a method for preparing photovoltaic panel dust removal gel based on coal gangue, which has a simple process and low cost. By improving photovoltaic dust removal technology, the resource utilization of coal gangue can be realized.

[0012] (2) The brushable hydrogel of the present invention utilizes the synergistic effects of viscoelastic adsorption, porous interception and mineral barrier to efficiently remove tiny particles on the surface of photovoltaic panels compared to traditional dust removal methods, and the dust removal effect is significantly improved.

[0013] (3) Traditional photovoltaic panel dust removal not only consumes a lot of manpower and water resources, but may also damage the equipment due to frequent operation. The present invention uses multi-source solid waste to prepare hydrogel, with low raw material cost, simple preparation and brushing operations, and effectively reduces maintenance costs.

[0014] In summary, since hydrogel materials are considered as potential solutions due to their three-dimensional network structure and high adsorption, the present invention constructs an independent gel system based on the characteristics of coal gangue: the coal gangue-based minerals are crushed to 100-200 mesh, the coal gangue is calcined, and the aluminum is extracted by acid leaching and the silicon is extracted by alkali fusion. Then, hydroxyethyl cellulose is added to the composite nano-silicon / aluminum sol to enhance the thixotropy and silane coupling agent is added to improve the adhesion to form a certain amount of protective layer; the prepared gel is selectively brushed according to environmental parameters (temperature / humidity / particle concentration), and the particulate matter is efficiently removed through the synergistic effect of viscoelastic adsorption, porous interception and mineral barriers, reducing the particle concentration by 14.6% per megawatt photovoltaic system, in order to achieve the dual goals of solid waste resource utilization and photovoltaic clean efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Flow chart for the preparation of gangue-based mineral gel. DETAILED DESCRIPTION

[0016] The embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings and examples.

[0017] Embodiment 1: Figure 1 As shown, the method for preparing brushable hydrogel for adsorbing micro-particles from coal gangue of the present invention comprises the following steps: S1. Crushing the coarse-grained coal gangue into 100-200 meshes by a jaw crusher, calcining it in a muffle furnace at 750 °C for 2 h to decompose kaolinite into active SiO2 and Al2O3; S2, then carry out the acid leaching method to extract aluminum, use hydrochloric acid to leach for 3 hours, filter and remove iron, retain the filtrate, extract Al³⁺, and prepare an aluminum salt solution; S3, then use alkali dissolution method to extract silicon, after calcination, melt coal gangue and NaOH at a mass ratio of 1:1 at a certain temperature for 1 hour, and leaching with hot water to obtain sodium silicate solution; S4. Slowly acidify the sodium silicate solution with dilute hydrochloric acid to pH=3-4 to generate nano-SiO2 sol, then add sodium polyacrylate dispersant to the Al³⁺ solution and stir until transparent to obtain aluminum sol; S5, silica sol and aluminum sol were mixed in a volume ratio of 7:3, and 0.5% hydroxyethyl cellulose (HEC) was added to enhance thixotropy (to prevent sagging), 3% glycerol was added to improve flexibility and avoid cracking, and 1% silane coupling agent (KH-550) was added to promote cross-linking and substrate adhesion; S6. Apply the viscous mixed solution obtained in step S5 to the surface of the photovoltaic panel with dust (PM10) and cure it under sunlight for 2 hours to form a coal gangue gel layer.

[0018] The above embodiments illustrate the basic principles and features of the present invention, but the above only illustrates the preferred embodiments of the present invention and is not limited to the embodiments. Under the inspiration of this patent, a person skilled in the art can make many forms of deformation and improvement without departing from the scope of protection of the present invention and the claims, which are all within the protection scope of the present invention. Therefore, the patent and protection scope of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing brushable hydrogel for adsorbing micro-particles from coal gangue, characterized in that: The following steps are involved: S1. The coarse-grained coal gangue is crushed by a jaw crusher and calcined in a muffle furnace to decompose the coal gangue into active SiO2 and Al2O3; S2. First, the acid leaching method is used to extract aluminum. The coal gangue is leached with hydrochloric acid for 3 hours. After filtering and removing iron, the filtrate is retained to extract Al³⁺. Then, the alkali dissolution method is used to extract silicon. The calcined coal gangue is melted with NaOH at a certain temperature for 1 hour, and hot water is used to leaching to obtain a sodium silicate solution; S3, slowly acidify the sodium silicate solution with dilute hydrochloric acid to generate nano-SiO2 sol, then add sodium polyacrylate dispersant to the Al³⁺ solution, and stir until transparent to obtain aluminum sol; S4, silica sol and aluminum sol are mixed in a certain volume ratio, and a rheology regulator, a plasticizer and a curing agent are added to obtain a viscous mixed liquid; S5. The mixed liquid is evenly applied to the surface of the photovoltaic panel and cured under sunlight for a certain period of time to form a gel layer.

2. The method for preparing brushable hydrogel for adsorbing micro-particles from coal gangue according to claim 1, characterized in that: In step S1, the coal gangue is crushed to 100-200 mesh, the calcination temperature is 750°C, and the calcination time is 2 h.

3. The method for preparing brushable hydrogel for adsorbing micro-particles from coal gangue according to claim 2, characterized in that: In step S2, the mass ratio of coal gangue to NaOH is 1:

1.

4. The method for preparing brushable hydrogel for adsorbing micro-particles from coal gangue according to claim 3, characterized in that: In step S2, the coal gangue is leached with hydrochloric acid and acidified to pH=3-4.

5. The method for preparing brushable hydrogel for adsorbing micro-particles from coal gangue according to claim 1, characterized in that: In step S3, the volume ratio of nano-SiO2 sol to aluminum sol is 7:

3.

6. The method for preparing brushable hydrogel for adsorbing micro-particles from coal gangue according to claim 5, characterized in that: In step S4, the rheology regulator is hydroxyethyl cellulose (HEC), the plasticizer is glycerol, and the curing agent is a silane coupling agent (KH-550).

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