阅读说明：本技术 一种用于修复砷渣的稳定化药剂及其应用方法 (Stabilizing agent for repairing arsenic slag and application method thereof ) 是由 杨崎峰 朱红祥 周永信 宋海农 覃当麟 谢湉 廖长君 刘松豪 张涛 苏建 曹斐姝 于 2019-09-12 设计创作，主要内容包括：本发明公开了一种用于修复砷渣的稳定化药剂及其应用方法,该稳定化药剂由pH调节剂与高分子聚合物稳定剂按照质量比为0.5～1.5:1混合并经研磨粉碎而成。将稳定化药剂用于修复砷渣时,先将待修复砷渣风干并破碎,按砷渣干基质量的3～12％向砷渣中加入稳定化药剂并混合均匀,再向砷渣中加水至含水率为30～35％并混合均匀,养护1～5天,检测合格后填埋。本发明制备稳定化药剂的原材料廉价易得,制备成本低,修复方法工艺简单,处理量大,修复效率高,可应用于不同污染程度地块的大规模修复任务。(The invention discloses a stabilizing agent for repairing arsenic slag and an application method thereof, wherein the stabilizing agent is prepared by mixing a pH regulator and a high-molecular polymer stabilizer according to a mass ratio of 0.5-1.5: 1, and grinding and crushing the mixture. When the stabilizing agent is used for repairing arsenic slag, the arsenic slag to be repaired is firstly air-dried and crushed, the stabilizing agent is added into the arsenic slag according to the proportion of 3-12% of the dry basis weight of the arsenic slag and is uniformly mixed, then water is added into the arsenic slag until the water content is 30-35% and is uniformly mixed, the mixture is maintained for 1-5 days, and the arsenic slag is buried after the detection is qualified. The raw materials for preparing the stabilizing agent are cheap and easy to obtain, the preparation cost is low, the repair method is simple in process, the treatment capacity is large, the repair efficiency is high, and the method can be applied to large-scale repair tasks of plots with different pollution degrees.)

1. The stabilizing agent for repairing arsenic slag is characterized by being prepared by mixing a pH regulator and a high-molecular polymer stabilizer according to a mass ratio of 0.5-1.5: 1, and grinding and crushing the mixture.

2. The stabilizing agent for repairing arsenic slag according to claim 1, wherein the high molecular polymer stabilizing agent is one or any combination of polymeric ferric sulfate, polymeric ferric chloride, polymeric ferric aluminum sulfate and polymeric aluminum ferric silicate.

3. The stabilizing agent for repairing arsenic slag according to claim 1 or 2, wherein the pH regulator is calcium oxide.

4. The stabilizing agent for repairing arsenic slag according to claim 1 or 2, wherein the stabilizing agent is pulverized into powder with a mesh size of 400 meshes or more, and the specific surface area of the stabilizing agent is 10-21.3 m²The water content is less than or equal to 0.3 percent.

5. The method of using the stabilizing agent for arsenic slag remediation as claimed in any one of claims 1 to 4, wherein the method includes the steps of:

(1) air-drying the arsenic slag until the water content is less than or equal to 15%, and then crushing and screening until the particle size is less than or equal to 10mm to obtain an arsenic slag pile;

(2) adding a stabilizing agent into the arsenic slag pile according to the proportion of 3-12% of the dry basis weight of the arsenic slag, and uniformly mixing the stabilizing agent and the arsenic slag;

(3) adding clear water into the arsenic slag pile, stirring to uniformly increase the water content of the arsenic slag pile to 30-35%, covering the arsenic slag pile with a waterproof cloth, stabilizing for 1-5 days, and sampling and detecting;

(4) and (3) leaching and detecting the stabilized arsenic slag according to a horizontal oscillation method (HJ 557-2010) of a solid waste leaching toxicity leaching method, if the arsenic leaching is less than or equal to 2.5mg/L, transporting the arsenic slag to a landfill site for safe landfill disposal, and if the arsenic leaching is more than 2.5mg/L, returning the arsenic slag to the steps (2) and (3) for reprocessing.

6. The method for applying the stabilizing agent for repairing arsenic slag as claimed in claim 5, wherein in the step (4), the pH value of the arsenic slag transported to the landfill site is 7-9.

Technical Field

The invention belongs to the technical field of dangerous solid waste treatment, and particularly relates to a stabilizing agent for repairing arsenic slag and an application method thereof.

Background

Arsenic trioxide, commonly known as "arsenic" is an important chemical raw material, widely used in metallurgy, glass manufacturing, pesticides, medicine and other industries. A batch of countryside arsenic refining enterprises are emerged in succession all over the country, and the arsenic trioxide is produced by the method of calcining realgar ore. Generally, arsenic content in realgar ore is 15% -30%, according to statistics, 6-8 tons of ore needs to be calcined for producing one ton of arsenic trioxide, and 80% of the arsenic trioxide is discarded in the form of slag.

At present, the arsenic slag treatment technology in China mainly comprises a solidification/stabilization repair method, a chemical leaching repair method, a calcination method and the like, wherein the solidification/stabilization repair method becomes the main technology in the field of arsenic slag treatment at present due to the advantages of short repair period, large treatment capacity and low cost.

However, the traditional curing/stabilizing repair method only fixes the pollutants through the physical action of cement to reduce the contact surface between the pollutants and the outside, but still gradually increases the risk of pollutant exposure under the influence of microorganisms and environmental weathering; some methods simply add several medicaments separately and then stir the medicaments, so that the labor cost of a mechanical table is increased, and the use effect of the medicaments is influenced due to uneven mixing.

Chinese patent publication No. CN 108774024A discloses an arsenic slag solidified body and a method for solidifying and stabilizing arsenic slag, wherein arsenic slag, fly ash and/or slag, quicklime and calcium sulfate are mixed and ground to obtain a mixture, the mixture is fully and uniformly stirred with water, a water reducing agent and cement to obtain slurry, the slurry is poured into a mold for molding, and the repair is completed by curing and molding. The method has the advantages that the common solid waste arsenic-fixing material is used for saving resources, but the method has a complex curing process, and the capacity of the arsenic slag solidified body is increased too high by using a large amount of the curing material, so that the landfill cost is increased.

Chinese patent publication No. CN 102601108B discloses a method for treating arsenic-contaminated soil, comprising the following steps: the method comprises the steps of mixing the polluted soil with NaOH solution and hydrogen peroxide to form a semi-solid system, oxidizing low-valent arsenic in the semi-solid system under an alkaline condition, adding polymeric ferric sulfate into the oxidized polluted soil, mixing and stirring for reaction, and combining ferric salt with pentavalent arsenic to generate stable ferric arsenate. According to the method, low-valence arsenic in soil is oxidized and then subjected to a stabilization reaction, so that the stabilization efficiency is improved to a certain extent, but the method needs to add chemicals for many times, the treatment cost is increased, and the sodium hydroxide and hydrogen peroxide can damage the soil structure to a certain extent.

The Chinese patent publication No. CN 109943340A discloses a passivator for treating high-arsenic waste residue, which comprises the following components in percentage by weight: 5-20% of ferric sulfate or ferrous sulfate, 10-30% of fly ash, 5-10% of sodium silicate and the balance of filler, wherein the addition amount of the passivation agent accounts for 3-10% of the high-arsenic waste residue. The method has the advantages of low cost of raw materials of the adopted medicament and simple treatment process, but the stabilizing effect on arsenic is limited by singly using ferric sulfate and ferrous sulfate as stabilizing materials.

The Chinese patent publication No. CN 109943340A discloses an arsenic fixation method for preparing scorodite by stabilizing arsenic alkali residue, which comprises the following steps: 1) oxidizing and leaching the arsenic alkali residue, and filtering to obtain leachate containing sodium carbonate and sodium arsenate and sodium antimonate precipitate; introducing CO after the leaching solution is concentrated₂Dealkalizing, filtering to obtain dealkalized leachate and sodium bicarbonate crystals; 2) adding acid into the dealkalized leaching solution obtained in the step 1, and controlling the pH value of the dealkalized leaching solution to be 1.0-2.5 to obtain an arsenic-rich solution; 3) adding ferrous salt and H into the arsenic-containing solution obtained in the step 2 according to the molar ratio of iron to arsenic of 1.0-3.0₂O₂Controlling the pH of the mixed solution to be 1.2-2.0, and reacting at 75-95 ℃ to obtain the scorodite crystal. The method converts arsenic into stable scorodite, thereby greatly reducing the in-out risk, but the method can only carry out reaction in a liquid phase, needs to firstly oxidize and leach the arsenic in the arsenic slag, has complex process and is not suitable for large-scale production.

In summary, the current arsenic slag solidification/stabilization repair method still needs to solve the problems of complex repair process, high medicament price, low utilization rate and unsatisfactory repair effect.

Disclosure of Invention

The invention aims to provide a stabilizing agent for repairing arsenic slag and an application method thereof, wherein the stabilizing agent can rapidly react with pollutant arsenic to form stable arsenide precipitate, has good stabilizing effect and low treatment cost, and can adapt to the repair of plots with different pollution degrees.

The invention solves the technical problems by the following technical scheme:

the stabilizing agent for repairing arsenic slag is prepared by mixing a pH regulator and a high-molecular polymer stabilizer according to a mass ratio of 0.5-1.5: 1, and grinding and crushing.

The high molecular polymer stabilizer is one or any combination of polymeric ferric sulfate, polymeric ferric chloride, polymeric ferric aluminum sulfate and polymeric aluminum ferric silicate.

The pH regulator is calcium oxide.

The stabilizing agent is pulverized into powder with a mesh number of more than or equal to 400 meshes, and is stableThe chemical agent has a specific surface area of 10 to 21.3m²The water content is less than or equal to 0.3 percent.

The application method of the stabilizing agent for repairing arsenic slag comprises the following steps:

(1) air-drying the arsenic slag until the water content is less than or equal to 15%, and then crushing and screening until the particle size is less than or equal to 10mm to obtain an arsenic slag pile;

(2) adding a stabilizing agent into the arsenic slag pile according to the proportion of 3-12% of the dry basis weight of the arsenic slag, and uniformly mixing the stabilizing agent and the arsenic slag;

(3) adding clear water into the arsenic slag pile, stirring to uniformly increase the water content of the arsenic slag pile to 30-35%, covering the arsenic slag pile with a waterproof cloth, stabilizing for 1-5 days, and sampling and detecting;

(4) and (3) leaching and detecting the stabilized arsenic slag according to a horizontal oscillation method (HJ 557-2010) of a solid waste leaching toxicity leaching method, if the arsenic leaching is less than or equal to 2.5mg/L, transporting the arsenic slag to a landfill site for safe landfill disposal, and if the arsenic leaching is more than 2.5mg/L, returning the arsenic slag to the steps (2) and (3) for reprocessing.

In the step (4), the pH value of the arsenic slag transported to the landfill is 7-9.

Compared with the prior art, the invention has the following beneficial effects:

1) the stabilizing agent is prepared into an ultrafine powder state by premixing the effective components in the agent and grinding, and the ultrafine material has high specific surface, has stronger pollutant adsorption capacity and is easy to stir uniformly, so that the repair efficiency is improved. When clear water is added in the application process, the pH regulator and the high molecular polymer stabilizer in the medicament are quickly dissolved to generate ferric hydroxide/aluminum hydroxide colloids with large specific surface area, and the colloids can adsorb surrounding arsenic and continuously react to generate difficultly soluble arsenic-containing minerals, so that the leaching risk of the arsenic is substantially reduced.

2) The raw materials adopted by the preparation of the stabilizing medicament are cheap and easy to obtain, the preparation method is simple, the treatment process is feasible, the repair cost is low, and the stabilizing medicament has better economic benefit, environmental benefit and social benefit.

3) The method of the invention mainly improves the reaction area of the medicament and the arsenic slag by intensively mixing the effective components in the medicament and preparing the effective components into the ultrafine powder material, improves the stabilization efficiency, can finish the repair by adding and mixing the medicament once, can reduce the medicament usage amount and the machine shift amount, and greatly reduces the repair cost.

Detailed Description

The present invention will be described in further detail with reference to specific examples. It should be emphasized that the following description is merely exemplary in nature and is not intended to limit the scope of the invention or its application.

The invention relates to a stabilizing agent for repairing arsenic slag, which is prepared by the following steps:

mixing the pH regulator and the high molecular polymer stabilizer according to the mass ratio of 0.5-1.5: 1, feeding the mixture into a dry powder ball mill, grinding and crushing the mixture until the mesh number is more than or equal to 400 meshes, and packaging and forming the mixture by a packaging machine to obtain the pH regulator.

The high molecular polymer stabilizer is one or any combination of polymeric ferric sulfate, polymeric ferric chloride, polymeric ferric aluminum sulfate and polymeric aluminum ferric silicate.

The pH regulator is calcium oxide.

The specific surface area of the stabilizing agent is 10-21.3 m²The water content is less than or equal to 0.3 percent.

The application method of the stabilizing agent for repairing arsenic slag comprises the following steps:

(1) air-drying the arsenic slag until the water content is less than or equal to 15%, and then crushing the arsenic slag by using movable crushing and screening equipment until the particle size is less than or equal to 10mm to obtain an arsenic slag pile;

(2) adding a stabilizing agent into the arsenic slag pile according to the proportion of 3-12% of the dry basis weight of the arsenic slag, and uniformly mixing the stabilizing agent and the arsenic slag by using a crushing and screening bucket;

(3) adding clear water into the arsenic slag pile, stirring by using a movable stirring device to uniformly increase the water content of the arsenic slag pile to 30-35%, covering the arsenic slag pile with a waterproof cloth, and sampling and detecting after stabilizing for 1-5 days;

(4) and (3) leaching and detecting the stabilized arsenic slag according to a horizontal oscillation method (HJ 557-2010) of a solid waste leaching toxicity leaching method, if the arsenic leaching is less than or equal to 2.5mg/L, transporting the arsenic slag to a landfill site for safe landfill disposal, and if the arsenic leaching is more than 2.5mg/L, returning the arsenic slag to the steps (2) and (3) for reprocessing.

And (3) adding a stabilizing agent into the arsenic slag for repairing, and detecting to be qualified, wherein the pH value of the arsenic slag is 7-9.

The following are examples of the present invention: