High-efficiency preparation method of nano silicon dioxide based on biomass power plant ash

Abstract

The invention discloses an efficient preparation method of nano silicon dioxide based on biomass power plant ash. The method comprises the following steps: crushing, sieving and drying the biomass power plant ash; then an HCl solution with the concentration not exceeding 5 mol / L is added according to the solid-to-liquid ratio of 1: 8-1: 10, after constant-temperature heating reflux, suction filtration and drying are conducted, and acid pretreatment ash is obtained; mixing the acid-pretreated ash and NaOH solid according to a mass ratio of 1: 0.6-1: 1.4, and activating at high temperature to obtain alkali-molten ash; adding the alkali fusion ash into a NaOH solution with the concentration of not more than 5mol / L according to the solid-to-liquid ratio of 1: 8-1: 10, carrying out constant-temperature heating reflux, and carrying out suction filtration to obtain a filtrate which is a water glass solution; and finally, introducing CO2 into the water glass solution in a constant-temperature water bath kettle at a certain rate for a period of time, stopping introducing CO2, aging for 0-72 hours under a normal-temperature condition, carrying out suction filtration, and drying, so as to obtain the nano silicon dioxide. According to the method, the waste biomass ash is used as the raw material, the cost is low, the process is simple, the prepared nano silicon dioxide is high in purity and extraction rate, waste resource utilization is achieved, and the preparation cost of the nano silicon dioxide is reduced.

Description

Technical Field

[0001] This invention relates to the field of silica preparation technology, and in particular to a highly efficient method for preparing nano-silica based on biomass power plant ash slag. Background Technology

[0002] Silica, especially nanoscale silica, is widely used in numerous fields such as rubber, plastics, coatings, adsorbents, drug carriers, and electronic materials due to its high specific surface area, excellent chemical stability, good mechanical strength, and unique surface effects. With the development of high-tech industries, the demand for high-purity, low-cost nanoscale silica is increasing daily.

[0003] The existing industrial preparation methods for silica mainly include the gas phase method and the precipitation method. Although the gas phase method can produce high-purity products, the preparation process is energy-intensive and costly, which limits its large-scale application. The precipitation method usually uses quartz sand or industrial water glass as the silicon source and prepares it through acid hydrolysis or carbonation precipitation. However, this method is the same as the gas phase method, and also suffers from high energy consumption and high cost.

[0004] Biomass power plant ash has a complex composition, mainly consisting of SiO2, Al2O3, Fe2O3, CaO, MgO, K2O, P2O5, and SO3, as well as small amounts of MnO, TiO2, Na2O, unburned carbon, and a small amount of organic matter. Currently, the utilization of biomass ash is mostly focused on blending into building materials, soil improvement, and silica extraction.

[0005] Therefore, this invention proposes a method for preparing high-value-added, high-purity nano-silica from direct combustion ash of biomass power plants with a high extraction rate. This method reduces the cost of silica while also improving the resource utilization of direct combustion ash from biomass power plants. Summary of the Invention

[0006] The present invention aims to provide an efficient method for preparing nano-silica based on biomass power plant ash, with the goal of reducing the preparation cost of silica and increasing the resource utilization of direct combustion ash from biomass power plants.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A method for efficiently preparing nano-silica based on biomass power plant ash residue includes the following steps:

[0009] S1. Raw material preparation and crushing: Take biomass ash from the power plant, crush it with a crusher, sieve it, and dry it with a blower to obtain pre-treated biomass ash.

[0010] S2. Add the pretreated biomass ash to an HCl solution with a concentration greater than 0 and not exceeding 5 mol / L at a solid-liquid ratio of 1:8-1:10. Under magnetic stirring, heat and reflux, then filter and dry the filter residue to obtain the acid-pretreated biomass ash.

[0011] S3. The pretreated biomass ash is mixed with NaOH solid at a ratio of 1:0.6-1:1.4 and placed in a muffle furnace. After high-temperature activation, the alkali-fused biomass ash is obtained.

[0012] S4. Add the alkali-fused biomass ash residue to a NaOH solution with a concentration greater than 0 and not exceeding 5 mol / L at a solid-liquid ratio of 1:8-1:10. Under magnetic stirring, heat and reflux, then filter and place the filtrate in a gas washing bottle to obtain water glass.

[0013] S5. Place the water glass in a constant temperature water bath, introduce CO2, and stop after a certain time. Let it stand at room temperature for a certain time, then filter and dry the filter residue to obtain nano-silica.

[0014] Furthermore, in step S1, when the pulverizer crushes and sieves the biomass ash, the particle size is controlled to be 80 mesh.

[0015] Furthermore, in step S2, the heating temperature is set to 90°C and the time is 2 hours.

[0016] Furthermore, the HCl solution added in step S2 is a concentrated hydrochloric acid diluted to a concentration greater than 0 mol / L and not exceeding 5 mol / L.

[0017] Furthermore, in step S3, the alkali fusion temperature is 350℃-750℃, and the time is 1 hour.

[0018] Furthermore, in step S4, the heating temperature is set to 90°C and the time is 2.5 hours.

[0019] Furthermore, in step S4, the NaOH solution is a NaOH solution prepared from solid NaOH with a concentration greater than 0 mol / L and not exceeding 5 mol / L.

[0020] Furthermore, in step S5, the temperature of the constant temperature water bath is 90℃, the CO2 ventilation time is set to 1.5h, and the aging time is controlled within 72h.

[0021] The principle and beneficial effects of this technical solution: The present invention is a method for the efficient preparation of nano-silica, which uses direct combustion ash from biomass power plants as the silicon source. After alkali melting, Na2SiO3 solution is prepared by mixing, and then nano-silica is obtained by carbonation and precipitation with CO2.

[0022] The preparation method of this invention improves the extraction efficiency to over 90% while ensuring the various excellent properties of nano-silica. It provides a low-cost but highly effective silicon source for the preparation of nano-silica, further reducing the cost of nano-silica and broadening the avenues for the resource utilization of direct combustion ash from biomass power plants, achieving a win-win situation for both economic and environmental benefits. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the preparation process of the method of the present invention. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments:

[0025] like Figure 1 The diagram shown is a schematic flow chart of a highly efficient method for preparing nano-silica based on biomass power plant ash slag according to the present invention. The preparation method of the present invention will now be described in detail with reference to the schematic chart and specific embodiments:

[0026] Example 1

[0027] A highly efficient method for preparing nano-silica based on biomass power plant ash (corn stalk ash) includes the following steps:

[0028] S1. Raw material preparation and crushing: Take corn stalk ash from biomass power plant, crush it with a crusher and pass it through an 80-mesh sieve to control the particle size of corn stalk ash to 80 mesh. After drying by forced air, the pre-treated corn stalk ash is obtained.

[0029] S2. The pretreated corn stalk ash residue was added to a 3 mol / L HCl solution at a solid-liquid ratio of 1:8. Under magnetic stirring, the mixture was heated and refluxed at 90°C for 2 hours, then filtered and the filter residue was dried to obtain the acid-pretreated corn stalk ash residue.

[0030] S3. The acid-treated corn stalk ash residue and NaOH solid were mixed in a ratio of 1:1.2 and placed in a muffle furnace. After activation at 550℃ for 1 hour, the alkali-fused corn stalk ash residue was obtained.

[0031] S4. The alkali-fused corn stalk ash residue was added to a 3 mol / L NaOH solution at a solid-liquid ratio of 1:8. Under magnetic stirring, the solution was heated and refluxed at 90°C for 2.5 h. After filtration, the filtrate was placed in a gas washing bottle to obtain water glass.

[0032] S5. Place the water glass in a 90℃ constant temperature water bath, and then stop the CO2 flow for 1.5 hours. After aging at room temperature for 12 hours, filter the residue and dry it to obtain nano-silica.

[0033] The obtained nano-silica sample was analyzed, and the purity of the nano-silica was found to be 92.73%, with a DBP oil absorption value of 2.7 × 10⁻⁶. -3 m 3 The extraction yield of silica with a particle size of 10nm-50nm and an extraction rate of 93.11% per kg indicates that this invention can extract high-purity silica with a high extraction rate.

[0034] Example 2

[0035] A highly efficient method for preparing nano-silica based on biomass power plant ash (rice husk ash) includes the following steps:

[0036] S1. Raw material preparation and crushing: Take rice husk ash from biomass power plant, crush it with a crusher and pass it through an 80-mesh sieve to control the particle size of rice husk ash to 80 mesh. After drying by forced air, the pre-treated rice husk ash is obtained.

[0037] S2. The pretreated rice husk ash residue was added to a 3mol / L HCl solution at a solid-liquid ratio of 1:10. Under magnetic stirring, the mixture was heated and refluxed at 90°C for 2 hours, then filtered and the filter residue was dried to obtain acid-pretreated rice husk ash residue.

[0038] S3. The acid-treated rice husk ash residue and NaOH solid were mixed in a ratio of 1:1.2 and placed in a muffle furnace. After activation at 550℃ for 1 hour, the alkali-fused rice husk ash residue was obtained.

[0039] S4. Add the alkali-fused rice husk ash residue to a 3 mol / L NaOH solution at a solid-liquid ratio of 1:10. Under magnetic stirring, heat and reflux at 90°C for 2.5 h, then filter and place the filtrate in a gas washing bottle to obtain water glass.

[0040] S5. Place the water glass in a 90℃ constant temperature water bath, and then stop the CO2 flow for 1.5 hours. After aging at room temperature for 12 hours, filter the residue and dry it to obtain nano-silica.

[0041] The obtained nano-silica sample was analyzed, and the purity of the nano-silica was found to be 95.64%, with a DBP oil absorption value of 3.2 × 10⁻⁶. -3 m 3 The extraction yield is 92.32% per kg of silica with a particle size of 10nm-50nm, indicating that the present invention can extract high-purity silica with a high extraction rate.

[0042] In summary, the preparation method of this invention addresses the current problems of low utilization rate of biomass power plant ash and difficulties in the extraction and preparation of high-purity nano-silica. By utilizing acid washing, alkali melting, and recarbonization, the activity of silica in the direct-fired corn stalk ash of biomass power plants is controlled. Subsequently, CO2 carbonation decomposition is employed to extract high-value-added, high-purity nano-silica from the direct-fired ash of biomass power plants at a high extraction rate. This research not only broadens the utilization pathways of direct-fired ash from biomass power plants but also provides new possibilities and directions for the preparation of nano-silica in practical engineering applications.

[0043] The above descriptions are merely embodiments of the present invention, and common technical solutions or characteristics known in the schemes are not described in detail here. For those skilled in the art, various modifications and improvements can be made without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application shall be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for efficient production of nanosilica based on biomass power plant ash, characterized by, The method comprises the following steps: S1, raw material preparation and crushing treatment, taking the biomass direct combustion ash of power plant, crushing with a crusher, sieving, and drying with air to obtain pretreated biomass ash; S2, the pretreated biomass ash is added to an HCl solution with a concentration greater than 0 and not more than 5 mol / L at a solid-liquid ratio of 1:8-1:10, heated under magnetic stirring, filtered, and the filter residue is dried to obtain acid pretreated biomass ash; S3, the acid pretreated biomass ash is mixed with NaOH solid at a mixing ratio of 1:0.6-1:1.4 in a muffle furnace, and high-temperature activated to obtain alkali melted biomass ash; S4, the alkali melted biomass ash is added to a NaOH solution with a concentration greater than 0 and not more than 5 mol / L at a solid-liquid ratio of 1:8-1:10, heated under magnetic stirring, filtered, and the filtrate is placed in a gas washing bottle to obtain water glass; S5, the water glass is placed in a constant temperature water bath, CO2 is introduced, the introduction is stopped after a certain time, and the filter residue is obtained after aging for a certain time at room temperature, and then dried to obtain nano silicon dioxide.

2. A method for efficient preparation of nano-silica based on biomass power plant ash according to claim 1, characterized by: In the step S1, the particle size of the biomass ash is controlled to pass through an 80-mesh sieve when the crusher is crushed and sieved.

3. The method according to claim 1, wherein the biomass power plant ash is used as a raw material for the preparation of nanosilica. In the step S2, the heating temperature is set to 90°C, and the time is 2h.

4. The method according to claim 1, wherein the biomass power plant ash is used as a raw material for the preparation of nanosilica. In the step S2, the HCl solution added is concentrated hydrochloric acid diluted to an HCl solution with a concentration greater than 0 mol / L and not more than 5 mol / L.

5. The method according to claim 1, wherein the biomass power plant ash-based nanosilica is prepared efficiently. In the step S3, the alkali melting temperature is 350-750°C, and the time is 1h.

6. A method for efficient production of nano-silica based on biomass power plant ash according to claim 1, characterized by: In the step S4, the heating temperature is set to 90°C, and the time is 2.5h.

7. The method according to claim 1, wherein the biomass power plant ash is used as a raw material for the production of nanosilica. In the step S4, the NaOH solution is a NaOH solution with a concentration greater than 0 mol / L and not more than 5 mol / L prepared by NaOH solid.

8. The method according to claim 1, wherein the biomass power plant ash-based nanosilica is prepared efficiently. In the step S5, the temperature of the constant temperature water bath is 90°C, the CO2 introduction time is set to 1.5h, and the aging time is controlled within 72h.

Images