Solidification and stabilization treatment composite agent and application thereof in stabilization treatment of bulk solid waste

Abstract

The invention discloses a curing and stabilizing treatment composite agent, which belongs to the field of harmless treatment and resource utilization of solid wastes, and comprises a liquid targeting agent, a reinforced curing agent, a liquid targeting agent composition, 50-80% by mass of an organic targeting agent and 20-50% by mass of a saturated acid-base adjusting buffer agent, when the curing and stabilizing treatment composite agent is applied to curing and stabilizing treatment of a large amount of solid waste, experimental results show that the total leaching concentration of toxic and harmful substances in the solid waste is lower than 2 mg / L, and the curing and stabilizing efficiency is higher than 95%; the composite agent disclosed by the invention avoids the defect of non-uniform mixing of a traditional powder targeting agent and the solid waste, is convenient to transport and use, can realize treatment of a large amount of solid waste by directly utilizing a spraying device, reduces the labor and transportation cost, and is beneficial to large-scale harmless treatment of the large amount of solid waste.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of solid waste harmless and resource utilization, and particularly relates to a solidification and stabilization treatment composite agent and application thereof in bulk solid waste stabilization treatment. BACKGROUND

[0002] With the continuous expansion of the development scale of mineral resources in China, the annual production of bulk industrial solid waste such as fly ash, phosphogypsum and tailings has broken through 3 billion tons, which generally contains high-mobility phosphorus, fluorine and heavy metal pollutants such as lead, cadmium and chromium. Open-air storage leads to continuous release of toxic components: phosphorus forms soluble phosphate under the action of acid rain, accelerating water eutrophication, fluorine penetrates through leaching, causing groundwater to exceed the standard, and heavy metals are enriched through the food chain, threatening human health. Traditional powder agent technologies such as cement solidification and lime stabilization have defects such as uneven mixing, large volume increase ratio (30%-50%), and the like, and the fixation rate of phosphorus / flourine is less than 60%, and the solidified body is prone to heavy metal "desorption" under acid rain erosion. The defects of traditional solidified body relying on physical encapsulation and weak chemical bonding capacity accelerate the deterioration under the environmental stress of acid rain erosion, freeze-thaw cycle and the like. It is difficult to meet the stringent requirements of the Solid Waste Pollution Environment Prevention Law on long-term stability.

[0003] The current solidification and stabilization technology faces three challenges: first, the powder agent (such as cement, bentonite) has a low contact efficiency of less than 65% when mixed with micro-fine solid waste particles due to the difference in particle size and density, forming a local unreacted area, which causes pollutants to be released through a "short path"; second, a single agent cannot cooperatively fix phosphorus, fluorine and multi-valent heavy metals with different chemical behaviors--lime can precipitate fluorine to form CaF2, but the strong alkaline environment will activate the amphoteric metals zinc and chromium, and phosphate stabilizers are ineffective for anionic phosphorus / flourine; third, the powder agent has poor penetration in situ repair scenarios, and the pollution site repair case shows that the in-situ injection coverage is insufficient, and the cost per ton of treatment is high. Although the liquid agent can improve the dispersion uniformity, ordinary aqueous carriers are easy to form flocculent precipitates with iron and aluminum ions in the solid waste, blocking the pores, and lack a multi-pollutant synchronous targeting mechanism.

[0004] In view of the above defects, it is a key technical requirement to develop a liquid target agent that can simultaneously stabilize phosphorus, fluorine and heavy metals, adapt to large-area in-situ application and consider long-term stability, which has become a key technical requirement to solve the problem of powdery bulk solid waste pollution. SUMMARY

[0005] The present application provides a solidification and stabilization treatment composite agent, which solves the problems of uneven mixing of traditional bulk solid waste targeting solidification and stabilization treatment, poor long-term solidification and stabilization effect, high construction difficulty and high cost.

[0006] The curing and stabilization treatment composite agent comprises a liquid targeting agent and a reinforced curing agent.

[0007] The organic targeting agent is selected from sodium polyacrylate, acrylic acid, lithium silicate, polyvinyl alcohol, sodium alginate, 3-acrylamidopropyl trimethylammonium chloride, acrylic acid, polyacrylamide, polyaluminum chloride, polyferric sulfate, polyaluminum sulfate, polyisobutylene, and polyimide.

[0008] The acid-base adjusting buffer is one of saturated solutions of buffer acetic acid-sodium acetate, ammonia-ammonium chloride, carbonate, bicarbonate, Tris, borate, citrate, HEPES, PIPES, MOPS, MES, CHES, CAPS, Bicine, and Tricine.

[0009] The reinforced curing agent is one of polyvinyl acetate, polyurethane and epoxy resin, ethyl acrylate, acrylic acid, cyanoacrylate, acrylate, epoxy acrylate, epoxy resin, polyurethane, amino resin, phenolic resin, acrylic resin, furan resin, resorcinol-formaldehyde resin, xylene-formaldehyde resin, unsaturated polyester, composite resin, and urea-formaldehyde resin.

[0010] Another object of the present application is to apply the curing and stabilization treatment composite agent to curing and stabilization treatment of bulk solid waste, specifically, the liquid targeting agent is diluted with water at a volume ratio of 40-60%, and then uniformly sprayed into the bulk solid waste, and then sealed and cured for 1-6 hours; the reinforced curing agent with a mass percentage of 1-20% of the bulk solid waste is sprayed into the cured bulk solid waste, and then placed for 30-150 minutes to realize the curing and stabilization treatment of the bulk solid waste.

[0011] The bulk solid waste in the present application is P-, F- and heavy metal-containing solid waste, which is selected from phosphogypsum, flue gas desulfurization gypsum, titanium gypsum, fluorogypsum, phosphorus tailings, copper tailings, vanadium-titanium-magnetite tailings, lead-zinc tailings, antimony tailings, tin tailings, and mercury tailings, and has a water content of less than 20%.

[0012] The total leaching concentration of toxic and harmful substances in the solid waste treated by the method of the present application is less than 2 mg / L, and the curing and stabilization efficiency is greater than 95%.

[0013] The beneficial effects of the present application are: in the present application, the solid waste containing phosphorus, fluorine and heavy metals is uniformly sprayed after being diluted with water with the liquid targeting agent, and the pollutant molecules are locked at the molecular level through closed curing; then the strong curing agent is sprayed to form an organic-inorganic hybrid network, so that the total leaching concentration of toxic and harmful substances is reduced to below 2 mg / L, and the solidification and stabilization efficiency breaks through 100%. The treated solid waste can significantly reduce the environmental risk in subsequent resource utilization.

[0014] From the perspective of environmental protection: the present application blocks the environmental release risk of phosphorus, fluorine and heavy metals from the source, and the leaching concentration of toxic substances is reduced to below 2 mg / L after step-by-step solidification by the liquid targeting agent; the short-term closed curing (1-6h) combined with low-temperature resource utilization process reduces the energy consumption per ton of solid waste treatment and reduces the carbon footprint, and the solidified body can be directly converted into an ecologically safe building material, realizing the full life cycle environmental protection closed loop of large-scale harmless treatment.

[0015] From the perspective of sustainable development, the present method has important strategic significance. On the one hand, this method can realize the resource utilization of industrial waste and reduce environmental pollution, which meets the strategic requirements of national sustainable development. On the other hand, this method can provide a cheap and feasible technical method for large-scale solid waste harmless treatment. In addition, this method can also drive the development of related industries such as solid waste treatment industry, smelting industry and agriculture, creating more employment opportunities and economic benefits.

[0016] The composite agent avoids the uneven mixing of traditional powder targeting agent with solid waste, and is convenient for transportation and use. Direct use of spraying device can realize the treatment of large-scale solid waste, reduce labor and transportation cost, and is beneficial to large-scale harmless treatment of large-scale solid waste, and has broad development prospect. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is the effect schematic diagram after the phosphogypsum solidification and stabilization treatment of Example 1; Figure 2 It is the effect schematic diagram after the copper tailings solidification and stabilization treatment of Example 2; Figure 3 It is the effect schematic diagram after the vanadium-titanium magnetite tailings solidification and stabilization treatment of Example 3. DETAILED DESCRIPTION

[0018] The present application will be further described below by means of the accompanying drawings and examples, but the scope of protection of the present application is not limited to the content described, and the methods in the examples are all conventional methods unless otherwise specified, and the reagents used are all conventional commercially available reagents or reagents prepared according to conventional methods unless otherwise specified.

[0019] Examples 1-3: Preparation of solidification and stabilization treatment composite agent 1. A composite agent 50%~80% organic targeting agent and 20%~50% saturated acid-base adjusting buffer are compounded to obtain a liquid targeting agent, and the specific formula is shown in Table 1. Table 1 ; 2. The liquid targeting agent is diluted with water, and then sprayed into the bulk solid waste at a dosage of 5-10 L / ton, and then sealed and cured for 1~6h; a solidification enhancer is sprayed into the cured solid waste at a dosage of 1%~20% of the mass of the solid waste, and then left to stand for 30~150min, as shown in Table 2. Table 2 .

[0020] Example 4: Application effect test of the composite agent for solidification and stabilization treatment in Examples 1-3 In the following examples, the leaching toxicity experiment is carried out according to the “Solid Waste Leaching Toxicity Leaching Method Horizontal Oscillation Method (HJ 557-2010)”; The application effect of the composite agent for solidification and stabilization treatment in Example 1 is shown in Figure 1 As shown in the figure, after standing for 30min, the leaching concentrations of P, F, As, Mn, Cr, Cd, Hg, Pb, Zn and Cu are reduced from 20mg / L, 21mg / L, 1.2mg / L, 24mg / L, 10mg / L, 5.2mg / L, 0.5mg / L, 13.2mg / L, 102mg / L and 120mg / L before treatment to 0.5mg / L, 1.2mg / L, 0.01mg / L, 0.01mg / L, 0.01mg / L, 0.01mg / L, 0.01mg / L, 0.01mg / L, 0.01mg / L and 0.1mg / L respectively; after standing for 2h, the total leaching concentration is lower than 0.11mg / L.

[0021] The application effect of the composite agent for solidification and stabilization treatment in Example 2 is shown in Figure 2 As shown in the figure, after standing for 30min, the leaching concentrations of P, F, As, Mn, Cr, Cd, Hg, Pb, Zn and Cu are reduced from 60mg / L, 60mg / L, 52mg / L, 150mg / L, 30mg / L, 23mg / L, 2.1mg / L, 74mg / L, 532mg / L and 25mg / L before treatment to 0.1mg / L, 0.2mg / L, 0.01mg / L, 0.01mg / L, 0.01mg / L, 0.01mg / L, 0.01mg / L, 0.01mg / L, 0.01mg / L and 2mg / L respectively; after standing for 2h, the total leaching concentration is lower than 0.1mg / L.

[0022] The application effect of the solidification and stabilization treatment composite agent of Example 3 is shown in Table 3 Figure 3 As can be seen from the figure, after placing for 30 min, the leaching concentrations of P, F, As, Mn, Cr, Cd, Hg, Pb, Zn and Cu are reduced from 38.2 mg / L, 15.6 mg / L, 1.2 mg / L, 24 mg / L, 12.4 mg / L, 25.2 mg / L, 0.5 mg / L, 113.2 mg / L, 102 mg / L, 120 mg / L before treatment to 0.1 mg / L, 1.2 mg / L, 0.01 mg / L, 0.01 mg / L, 0.01 mg / L, 0.01 mg / L, 0.01 mg / L, 0.01 mg / L, 0.01 mg / L and 2 mg / L respectively; after placing for 2 h, the total leaching concentration is lower than 1.5 mg / L.

Claims

1. A composite agent for solidification and stabilization treatment, characterized in that: It includes a liquid targeting agent, an enhanced curing agent, a liquid targeting agent composition and a mass percentage of 50% to 80% of an organic targeting agent and 20% to 50% of a saturated acid-base regulating buffer.

2. The composite agent for curing and stabilizing treatment according to claim 1, characterized in that: The organic targeting agent is selected from sodium polyacrylate, acrylic acid, lithium silicate, polyvinyl alcohol, sodium alginate, 3-acrylamidopropyl, trimethylammonium chloride, acrylic acid, polyacrylamide, polyaluminum chloride, polyferric sulfate, polyaluminum sulfate, polyisobutylene, and polyimide.

3. The composite agent for curing and stabilizing treatment according to claim 1, characterized in that: The saturated acid-base adjustment buffer is one of the saturated solutions of the buffers acetic acid-sodium acetate, ammonia-ammonium chloride, carbonate, bicarbonate, Tris, borate, citrate, HEPES, PIPES, MOPS, MES, CHES, CAPS, Bicine, and Tricine.

4. The composite agent for curing and stabilizing treatment according to claim 1, characterized in that: The reinforcing curing agent is one of polyvinyl acetate, polyurethane and epoxy resin, ethyl acrylate, acrylic acid, cyanoacrylate, acrylate, epoxy acrylate, epoxy resin, polyurethane, amino resin, phenolic resin, acrylic resin, furan resin, resorcinol-formaldehyde resin, xylene-formaldehyde resin, unsaturated polyester, composite resin, and urea-formaldehyde resin.

5. Use of the composite agent for solidification and stabilization treatment according to any one of claims 1 to 4 in the solidification and stabilization treatment of bulk solid waste.

6. The use according to claim 5, characterized in that: Bulk solid waste is solid waste containing P, F and heavy metals, selected from phosphogypsum, flue gas desulfurization gypsum, titanium gypsum, fluorine gypsum, phosphate tailings, copper tailings, vanadium titanium magnetite tailings, lead zinc tailings, antimony tailings, tin tailings, and mercury tailings, and its moisture content is less than 20%.

7. The use according to claim 5, characterized in that: After diluting the liquid targeted agent with water at a volume ratio of 40-60%, spray it evenly into the bulk solid waste at a rate of 5-10L / ton and maintain in a closed environment for 1-6 hours; spray 1%-20% of the mass of the bulk solid waste with an enhanced curing agent into the cured solid waste and leave it for 30-150 minutes to achieve solidification and stabilization of the bulk solid waste.

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