All-solid-waste biomass ash-based light soil and preparation method thereof

Abstract

The invention discloses all-solid-waste biomass ash-based light soil and a preparation method thereof.The light soil is prepared from, by mass, 100 parts of solid materials, 40-80 parts of water, 2-4 parts of foaming agents and 2-4 parts of water reducing agents, and the solid materials are prepared from, by mass, 60-90 parts of biomass ash, 10-30 parts of slag and 5-10 parts of desulfurized gypsum. The method comprises the following steps: mixing the biomass ash, the slag, the desulfurized gypsum and part of water to form cementing material slurry, adding the remaining water into the foaming agent to form foaming liquid, and mixing the foaming liquid with the cementing material slurry after foaming to prepare the light soil. The biomass ash, the slag and the desulfurized gypsum are adopted as raw materials of the light soil, the engineering cost is greatly reduced, meanwhile, resource utilization of solid waste is achieved, pollution to the environment is reduced, and the all-solid-waste biomass ash-based light soil has the advantages of being good in fluidity, excellent in physical performance and the like and has wide application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of building materials, and in particular relates to a full-solid waste biomass ash-based lightweight soil and a preparation method thereof. Background Art

[0002] Lightweight soil is a kind of lightweight filling material in the field of engineering construction, which has the characteristics of light weight, self-supporting, durability, high fluidity, good sound insulation, heat insulation and excellent waterproof performance. Lightweight soil is widely used in overall filling of buildings, filling of building foundation pits, backfilling of pipelines, backfilling of underground structures, backfilling of abandoned tunnels and goafs, backfilling of underground spaces such as highway tunnels / railway tunnels / hydraulic tunnels, and road and bridge filling projects.

[0003] The main resource utilization of biomass is to use biomass power plants to generate electricity, and combustion will produce a large amount of biomass ash. The traditional way to deal with biomass ash is to landfill or directly pile it on site, which will cause a lot of land pollution and dust problems. The inability to effectively dispose of biomass ash has brought new problems and challenges to the entire industry. Therefore, a practical and feasible method that can consume a large amount of biomass ash resources is urgently needed.

[0004] In summary, it is urgent to study a fully solid waste biomass ash-based lightweight soil. Summary of the invention

[0005] Technical problems solved: In response to the above technical problems, the present invention provides a fully solid waste biomass ash-based lightweight soil and a preparation method thereof, which fully utilizes solid wastes such as biomass ash, slag and desulfurization gypsum, greatly reduces the preparation cost and production difficulty, and obtains lightweight soil with sufficient strength and fluidity.

[0006] Technical solution: A fully solid waste biomass ash-based lightweight soil, whose raw materials, by mass, include 100 parts of solid materials, 40-80 parts of water, 2-4 parts of foaming agent and 2-4 parts of water reducing agent, wherein the solid materials include: 60-90 parts of biomass ash, 10-30 parts of slag and 5-10 parts of desulfurized gypsum.

[0007] Preferably, the biomass ash is dried and ground to a fineness of no more than 100 mesh.

[0008] Preferably, the mass fraction of CaO in the biomass ash is not less than 12%.

[0009] Preferably, the slag is S95 grade granulated blast furnace slag.

[0010] Preferably, the mass fraction of calcium sulfate in the desulfurized gypsum is not less than 83%.

[0011] Preferably, the foaming agent is sodium lauryl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate or silicone resin polyether.

[0012] Preferably, the water reducing agent is a polycarboxylic acid water reducing agent having a water reducing rate of not less than 30%.

[0013] The method for preparing the above-mentioned all-solid waste biomass ash-based lightweight soil comprises the following steps: S1. The biomass ash, slag and desulfurized gypsum are mixed evenly, and then mixed with part of the water mixed with a water reducing agent to form a cementitious material slurry; S2. adding the remaining water to the foaming agent to form a foaming liquid, and mixing it with the cementitious material slurry after foaming to obtain the all-solid waste biomass ash-based lightweight soil.

[0014] Preferably, the mass ratio of the residual water to the foaming agent is 70-100:1.

[0015] Beneficial effects: The present invention adopts biomass ash as raw material, and adds slag, desulfurization gypsum and other materials to prepare all-solid waste biomass ash-based lightweight soil, thereby realizing the resource utilization and recyclability of biomass ash, slag and desulfurization gypsum, realizing the resource utilization of biomass ash, slag and desulfurization gypsum solid waste on the basis of reducing environmental pollution, and ensuring the fluidity and strength of the all-solid waste biomass ash-based lightweight soil on the basis of increasing the blending ratio of biomass ash, thereby meeting the design requirements.

[0016] The biomass ash and slag of the present invention contain rich compounds such as Al2O3, SiO2 and CaO, which are the chemical components of volcanic ash. Desulfurized gypsum can be used as an activator to improve the activity of biomass ash and slag, and the hydration reaction generates hydration products such as calcium aluminate and hydrated calcium silicate gel. At the same time, the surface of the biomass ash and the surface of the slag have opposite charges to avoid flocculation of the slurry. Based on the properties of the biomass ash, the fluidity and strength of the all-solid waste biomass ash-based lightweight soil can be improved.

[0017] The present invention adopts biomass ash as raw material and adds slag, desulfurized gypsum and other materials to prepare all-solid waste biomass ash-based lightweight soil. On the premise of meeting the requirements, the material cost is greatly reduced, and the preparation method is simple, which is suitable for large-scale promotion and use. DETAILED DESCRIPTION

[0018] The present invention is further described below in conjunction with specific examples, wherein the raw materials involved are all commercially available products. Example 1

[0019] A kind of all-solid waste biomass ash-based lightweight soil, the raw materials of which are calculated by mass, including 100 parts of solid materials, 50 parts of water, 2 parts of foaming agent and 2 parts of water reducing agent, wherein the solid materials include: 70 parts of biomass ash, 25 parts of slag and 10 parts of desulfurized gypsum. The biomass ash is dried and ground at 105°C, the fineness is not more than 100 mesh, the mass fraction of CaO is 13%, and the content of harmful substances meets the requirements of GB50164-2011; the slag adopts S95 grade granulated blast furnace slag; the mass fraction of calcium sulfate in the desulfurized gypsum is 85%; the foaming agent is sodium dodecyl sulfate, and the water reducing agent adopts a polycarboxylic acid water reducing agent with a water reducing rate of 30%.

[0020] The preparation method of the above-mentioned all-solid waste biomass ash-based lightweight soil is as follows: S1. The biomass ash, slag and desulfurized gypsum are mixed evenly, and then mixed with part of the water mixed with a water reducing agent to form a cementitious material slurry; S2. adding the remaining water to the foaming agent to form a foaming liquid, and mixing it with the cementitious material slurry after foaming to obtain the all-solid waste biomass ash-based lightweight soil.

[0021] Wherein, the mass ratio of the residual water to the foaming agent is 80:1. Example 2

[0022] A light soil based on all-solid waste biomass ash, the raw materials of which are calculated by mass, including 100 parts of solid materials, 60 parts of water, 2 parts of foaming agent and 2 parts of water reducing agent, wherein the solid materials include: 80 parts of biomass ash, 15 parts of slag and 5 parts of desulfurized gypsum. The biomass ash is dried and ground at 105°C, the fineness is not more than 100 mesh, the mass fraction of CaO is 13%, and the content of harmful substances meets the requirements of GB50164-2011; the slag adopts S95 grade granulated blast furnace slag; the mass fraction of calcium sulfate in the desulfurized gypsum is 85%; the foaming agent is sodium dodecyl sulfate, and the water reducing agent adopts a polycarboxylic acid water reducing agent with a water reducing rate of 30%.

[0023] The preparation method of the above-mentioned all-solid waste biomass ash-based lightweight soil is as follows: S1. The biomass ash, slag and desulfurized gypsum are mixed evenly, and then mixed with part of the water mixed with a water reducing agent to form a cementitious material slurry; S2. adding the remaining water to the foaming agent to form a foaming liquid, and mixing it with the cementitious material slurry after foaming to obtain the all-solid waste biomass ash-based lightweight soil.

[0024] Wherein, the mass ratio of the residual water to the foaming agent is 80:1. Example 3

[0025] A light soil based on all-solid waste biomass ash, the raw materials of which are calculated by mass, including 100 parts of solid materials, 70 parts of water, 3 parts of foaming agent and 3 parts of water reducing agent, wherein the solid materials include: 85 parts of biomass ash, 10 parts of slag and 5 parts of desulfurized gypsum. The biomass ash is dried and ground at 105°C, the fineness is not more than 100 mesh, the mass fraction of CaO is 13%, and the content of harmful substances meets the requirements of GB50164-2011; the slag adopts S95 grade granulated blast furnace slag; the mass fraction of calcium sulfate in the desulfurized gypsum is 85%; the foaming agent is sodium dodecyl sulfate; the water reducing agent adopts a polycarboxylic acid water reducing agent with a water reducing rate of 30%.

[0026] The preparation method of the above-mentioned all-solid waste biomass ash-based lightweight soil is as follows: S1. The biomass ash, slag and desulfurized gypsum are mixed evenly, and then mixed with part of the water mixed with a water reducing agent to form a cementitious material slurry; S2. adding the remaining water to the foaming agent to form a foaming liquid, and mixing it with the cementitious material slurry after foaming to obtain the all-solid waste biomass ash-based lightweight soil.

[0027] Wherein, the mass ratio of the residual water to the foaming agent is 80:1. Comparative Example 1

[0028] The difference between this comparative example and Example 1 is that no slag or desulfurized gypsum is added. Comparative Example 2

[0029] The difference between this comparative example and Example 2 is that no slag is added. Comparative Example 3

[0030] The difference between this comparative example and Example 3 is that no desulfurized gypsum is added. Comparative Example 4

[0031] A light soil based on all-solid waste biomass ash, the raw materials of which are calculated by mass, including 100 parts of solid materials, 50 parts of water, 2 parts of foaming agent and 2 parts of water reducing agent, wherein the solid materials include: 55 parts of biomass ash, 34 parts of slag and 11 parts of desulfurized gypsum. The biomass ash is dried and ground at 105°C, the fineness is not more than 100 mesh, the mass fraction of CaO is 13%, and the content of harmful substances meets the requirements of GB50164-2011; the slag adopts S95 grade granulated blast furnace slag; the mass fraction of calcium sulfate in the desulfurized gypsum is 85%; the foaming agent is sodium dodecyl sulfate; the water reducing agent adopts a polycarboxylic acid water reducing agent with a water reducing rate of 30%.

[0032] The preparation method of the above-mentioned all-solid waste biomass ash-based lightweight soil is as follows: S1. The biomass ash, slag and desulfurized gypsum are mixed evenly, and then mixed with part of the water mixed with a water reducing agent to form a cementitious material slurry; S2. adding the remaining water to the foaming agent to form a foaming liquid, and mixing it with the cementitious material slurry after foaming to obtain the all-solid waste biomass ash-based lightweight soil.

[0033] Wherein, the mass ratio of the residual water to the foaming agent is 80:1.

[0034] Liquidity test The fluidity test is carried out in accordance with CJJT177-2012. The main equipment includes 400mm×400mm smooth hard plastic plate, Φ80mm×80 hollow cylinder, depth vernier caliper, etc. The depth vernier caliper measures the maximum horizontal diameter of the slump body, which is the fluidity of the sample.

[0035] Unconfined compressive strength test The unconfined compressive strength test was carried out according to CJJT177-2012. The sample size was 100mm×100mm×100mm and was cured in a curing box at a temperature of 20±2℃ and a humidity greater than 95% to the specified age.

[0036] The relevant performance test results of all-solid waste biomass ash-based lightweight soil are shown in Table 1.

[0037] Table 1 Fluidity and unconfined compressive strength of self-curing, self-heat-conducting, anti-cracking fluidized soil

[0038] As can be seen from Table 1, the fluidity of the all-solid waste biomass ash-based lightweight soil of the present invention is not much different from that of the comparative example, and is basically at the same level, but the non-lateral compressive strength of the all-solid waste biomass ash-based lightweight soil of the present invention is much higher than that of the comparative example. The all-solid waste biomass ash-based lightweight soil of the present invention has a wide range of raw materials, a simple production process, no complicated process, and improves the recycling rate of solid waste resources. It has the characteristics of low cost and environmental friendliness while ensuring the application effect, and has broad application prospects.

Claims

1. A fully solid waste biomass ash-based lightweight soil, characterized in that: The raw materials thereof include, by mass, 100 parts of solid materials, 40-80 parts of water, 2-4 parts of foaming agents and 2-4 parts of water reducing agents, wherein the solid materials include: 60-90 parts of biomass ash, 10-30 parts of slag and 5-10 parts of desulfurized gypsum.

2. The all-solid waste biomass ash-based lightweight soil according to claim 1, characterized in that: The biomass ash is dried and ground to a fineness of no more than 100 meshes.

3. The all-solid waste biomass ash-based lightweight soil according to claim 1, characterized in that: The mass fraction of CaO in the biomass ash is not less than 12%.

4. The all-solid waste biomass ash-based lightweight soil according to claim 1, characterized in that: The slag is S95 grade granulated blast furnace slag.

5. The all-solid waste biomass ash-based lightweight soil according to claim 1, characterized in that: The mass fraction of calcium sulfate in the desulfurized gypsum is not less than 83%.

6. The all-solid waste biomass ash-based lightweight soil according to claim 1, characterized in that: The foaming agent is sodium lauryl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate or silicone resin polyether.

7. The all-solid waste biomass ash-based lightweight soil according to claim 1, characterized in that: The water reducing agent is a polycarboxylic acid water reducing agent with a water reducing rate of not less than 30%.

8. The method for preparing all-solid waste biomass ash-based lightweight soil according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. The biomass ash, slag and desulfurized gypsum are mixed evenly, and then mixed with part of the water mixed with the water reducing agent to form a cementitious material slurry; S2. adding the remaining water to the foaming agent to form a foaming liquid, and mixing it with the cementitious material slurry after foaming to obtain the all-solid waste biomass ash-based lightweight soil.

9. The method for preparing all-solid waste biomass ash-based lightweight soil according to claim 8, characterized in that: The mass ratio of the residual water to the foaming agent is 70-100:1.

Images