阅读说明：本技术 一种多效气态稳定剂及其重金属稳定化处理中的应用 (multi-effect gaseous stabilizer and application thereof in heavy metal stabilization treatment ) 是由 张英杰 梁率钰 瞿广飞 解若松 邓继加 唐鑫 于 2019-08-27 设计创作，主要内容包括：本发明公开了多效气态稳定剂,其为含有质量浓度5-10%PM2.5颗粒的硫化氢气体；将多效气态稳定剂应用在重金属稳定化处理中,可有效处理尾矿内重金属污染的土壤或长期放置尾矿所产生的重金属迁移污染物；本发明稳定剂在使用过程中不产生氢氧沉淀、使硫化氢气体循环利用,从而减少在循环工艺中产生的硫酸盐,降低了危险废弃物的处理工程量和成本,还可有效处理因工业矿业活动等产生有毒有害的硫化氢气体,具有较大潜力的技术应用前景。(The invention discloses a multi-effect gaseous stabilizer, which is hydrogen sulfide gas containing 5-10% of PM2.5 particles by mass concentration; the multi-effect gaseous stabilizer is applied to the heavy metal stabilization treatment, so that the heavy metal contaminated soil in the tailings or heavy metal migration pollutants generated by long-term tailing placement can be effectively treated; the stabilizer does not generate hydrogen and oxygen precipitates in the using process, so that the hydrogen sulfide gas is recycled, the sulfate generated in the recycling process is reduced, the treatment engineering quantity and the cost of hazardous wastes are reduced, the toxic and harmful hydrogen sulfide gas generated by industrial mining activities and the like can be effectively treated, and the stabilizer has a great potential technical application prospect.)

1. A multi-effect gaseous stabilizer characterized by: which is hydrogen sulfide gas containing 5-10% PM2.5 particles by mass concentration.

2. Use of the multi-effect gaseous stabilizer of claim 1 in heavy metal stabilization treatment, characterized in that: under the vacuum condition, the tailings or soil containing heavy metals fully contact and react with a multi-effect gaseous stabilizer and a compounding agent, the pretreated product is mixed with attapulgite soaked by the compounding agent, after the attapulgite is soaked for 4 to 6 hours, the soaked product is fully mixed with the multi-effect gaseous stabilizer under the stirring condition, the heavy metals are further stabilized and kept stand, the pH of the mixture is adjusted to 6.2 to 7.5 through an acidic regulator, hydrogen sulfide gas generated after the acidic regulator is added is used for preparing the multi-effect gaseous stabilizer, the mixture is subjected to solid-liquid separation, the heavy metals in the tailings or soil are converted into stable metal complexes and are discharged in a solid precipitation mode, the liquid recovers the heavy metals in an electrolysis mode, and the tail gas is adsorbed by one or more of nano ferroferric oxide particles, zeolite and anhydrous calcium chloride.

3. use according to claim 1, characterized in that: the compounding agent is dithiocarboxylic acid or/and calcium superphosphate, the mass ratio of the compounding agent to the tailings or soil containing heavy metals is 20-30%, and the addition amount of the multi-effect gaseous stabilizer is 15 mL/min.

4. Use according to claim 1, characterized in that: the acidity regulator is HCl or/and HBF₄。

5. Use according to claim 1, characterized in that: the attapulgite soaked by the compounding ingredient is prepared into a solution for soaking the attapulgite according to the mass ratio of the compounding ingredient to the attapulgite of 25-30%.

6. apparatus for performing the use of any of claims 1-5, wherein: comprises a spray tower (1), a soaking device (2), a stirring device (3), a standing device (4), a solid-liquid separation device (5), a tail gas treatment device (6) and an electrolysis device (15), wherein the upper part of the spray tower (1) is provided with a liquid inlet (10) and a gas outlet I (12), the lower part of the spray tower (1) is provided with a gas inlet (11) and a discharge port (13), the middle part of the spray tower (1) is provided with a feed inlet (7), the liquid inlet (10) is fixedly connected with a sprayer at the top of the spray tower, a vacuum pump (8) is connected on the feed inlet for vacuumizing, the discharge port (13) of the spray tower (1) is communicated with the soaking device (2), the soaking device (2) is communicated with the stirring device (3) through a lifting pump (14), the gas outlet I (12) of the spray tower is communicated with the stirring device (3), the stirring device (3) is communicated with the solid-, the solid-liquid separation device (5) is communicated with the tail gas treatment device (6), the gas outlet II (9) on the standing device (4) is communicated with the gas inlet of the spray tower (1), the solid-liquid separation device (5) is communicated with the electrolysis device (15), and the electrolysis device (15) is communicated with the standing device (4).

7. The apparatus of claim 6, wherein: the soaking device is provided with attapulgite soaked by the compounding agent.

8. The apparatus of claim 6, wherein: one or more of nano ferroferric oxide particles, zeolite and anhydrous calcium chloride are placed in the tail gas treatment device (6) and used for absorbing tail gas.

Technical Field

The invention relates to the field of environmental management, in particular to research, development and a process of a multi-effect gaseous stabilizer.

Background

As a large country of mineral resources, the release of heavy metals in tailings slag after mine development affects the natural environment and the health of human beings. Most tailings coexist with heavy metals such as lead, zinc, nickel, arsenic and the like and exist in the tailings in an exchangeable form, and the heavy metals in the tailings can permeate to the surface of the earth, underground water and soil along with rainwater due to dialysis, enrichment, migration and other actions in the stacking process of the tailings, so that environmental pollution is caused. The composition of the mineral of the tailings is complex, and the rainwater and the weathering degree are easy to cause the mineral to run off through the water body and the soil through leaching and diffusion in long-term accumulation, thereby threatening the surrounding environment. Because the tailings contain valuable heavy metals, the comprehensive utilization of mines and the recycling of the heavy metals in the tailings can realize reduction, harmless treatment and resource treatment, and become the key points of heavy metal pollution treatment at present.

At present, the prior art can be divided into the following: firstly, under the condition of low pH value, biological sulfate reducing bacteria and sodium sulfate are added to make sulfur circulate and utilize electrolytic device, and the metal is separated out at cathode, and oxide is produced at anode. The generated sulfur slurry participates in the preparation of hydrogen sulfide, but the process is complex and has complicated steps, the generated sulfate needs to be further treated, and in the reaction process, the reactor can not directly separate hydrogen sulfide gas because the pH value is increased by alkali liquor. Secondly, by using an alkali precipitation method, hydroxide such as sodium hydroxide is added to separate out heavy metals, but a large amount of calcium sulfate is easily generated, and alkali liquor needs to be treated. Thirdly, an ion exchange method is adopted, so that the sulfuric acid also becomes a final electron acceptor, and sulfate radicals are reduced into sulfide and metal to generate precipitation. The three methods can remove heavy metals in a certain way to avoid secondary pollution, but if sulfate reducing bacteria are added, carbon sources and nitrogen sources of the sulfate reducing bacteria are considered as growth energy sources and electron acceptors of the sulfate reducing bacteria, and the sulfate reducing bacteria mostly live under a neutral condition, have high requirements on pH control, and are not suitable for treating the surrounding environment of tailings.

The hydrogen sulfide is used as gas with strong reducibility, is slightly soluble in water, and can make Fe under the acidic condition³⁺Conversion to Fe²⁺、Cr⁶⁺Conversion to Cr³⁺At present, the method is mainly indirectly applied to the treatment of heavy metal wastewater and participates in sulfur circulation. Patent CN102120636A teaches that sulfide ions generated by dissociation of hydrogen sulfide gas canA liquid film is formed by sealing the reactor and loaded on the crystallization precipitation carrier. The method is applied under alkaline conditions, and is easy to generate hydroxide precipitates and is not easy to remove. Therefore, the gaseous stabilizer using hydrogen sulfide as a main component is combined with a stabilization process to treat the polluted soil and tailings in the mining area, and the method has the advantages of high potential, easiness in operation, high utilization rate and the like.

Disclosure of Invention

Aiming at the defects that the heavy metal pollution treatment technology is imperfect and secondary pollution is easy to cause in the prior art, the invention provides a multi-effect gaseous stabilizer which has the advantages of simple preparation, low pollution degree and the like; the multi-effect gaseous stabilizer is hydrogen sulfide gas containing 5-10% of PM2.5 particles by mass concentration.

Applying a multi-effect gaseous stabilizer to heavy metal stabilization treatment, namely, under the vacuum condition, enabling tailings or soil containing heavy metals to fully contact and react with the multi-effect gaseous stabilizer and a compounding agent, mixing a pretreated product with attapulgite soaked by the compounding agent, soaking for 4-6 hours, fully mixing the soaked product with the multi-effect gaseous stabilizer under the stirring condition, further stabilizing the heavy metals, standing, adjusting the pH of the mixture to 6.2-7.5 by an acid regulator, adding hydrogen sulfide gas generated by the acid regulator for preparing the multi-effect gaseous stabilizer, carrying out solid-liquid separation on the mixture, converting the heavy metals in the tailings or the soil into stable metal complexes, discharging the heavy metals in a solid precipitation form, recovering the heavy metals from the liquid in an electrolysis mode, and using nano ferroferric oxide particles as tail gas for tail gas, One or more of zeolite and anhydrous calcium chloride.

The compounding agent is dithiocarboxylic acid or/and calcium superphosphate, the mass ratio of the compounding agent to the tailings or soil containing heavy metals is 20-30%, and the addition amount of the multi-effect gaseous stabilizer is 15 mL/min.

The acidity regulator is HCl or/and HBF₄。

The attapulgite soaked by the compounding ingredient is prepared into a solution for soaking the attapulgite according to the mass ratio of the compounding ingredient to the attapulgite of 25-30%.

The invention also provides a device for completing the method, which comprises a spray tower, a soaking device, a stirring device, a standing device, a solid-liquid separation device and a tail gas treatment device, wherein the upper part of the spray tower is provided with a liquid inlet and a gas outlet I, the lower part of the spray tower is provided with a gas inlet and a discharge outlet, the middle part of the spray tower is provided with a feed inlet, a vacuum pump is connected to the feed inlet for vacuumizing, the discharge outlet of the spray tower is communicated with the soaking device, the soaking device is communicated with the stirring device through a lifting pump, the gas outlet I of the spray tower is communicated with the stirring device, the stirring device is communicated with the solid-liquid separation device through the standing device, the solid-liquid separation device is communicated with the tail gas treatment device, the gas outlet II on the standing device is communicated with the gas inlet of.

The soaking device is internally provided with attapulgite soaked by the compounding agent.

one or more of nano ferroferric oxide particles, zeolite and anhydrous calcium chloride are placed in the tail gas treatment device and used for absorbing tail gas.

In order to achieve the purpose of treating heavy metal in tailings and heavy metal ions in surrounding soil, the containers used in the stabilizing process are all vacuum sealed reactor containers, and a vacuum pump extractor is arranged at the front end of each reactor container; the whole process in the process device is in an anaerobic condition, so that the spontaneous combustion of hydrogen sulfide is prevented; the air in the device is pumped out through the vacuum pump, the reactant is introduced into the spray tower from the feed inlet, the multiple-effect gaseous stabilizer is injected from the air inlet at the bottom of the spray tower, the compounding agent liquid is injected from the liquid inlet at the top of the spray tower, and the compounding agent is uniformly sprayed onto the reactant through the sprayer, so that the PM2.5 gaseous particulate matters are adsorbed on the reactant, and the sparse base contained in the compounding agent is captured. After pretreatment in a spray tower, the mixture is introduced into a soaking device to be mixed with attapulgite soaked by a compounding agent, and the compounding agent and the surface of the mixture contain a large amount of mercapto groups and phosphorus groups which can be complexed with hydroxyl groups on the surface of the attapulgite to generate a heavy metal complex; after soaking for 4-6h, conveying the mixture to a stirring device through a lift pump, simultaneously conveying unreacted gas in the spray tower into the stirring device from a gas outlet, fully stirring for 2-3h, conveying the mixture to a standing device, and adding an acidic regulator into the standing device to adjust the pH value to 6.2-7.5. Hydrogen sulfide generated in the standing device is derived from a small amount of chlorine generated in an electrolytic device and dissolved in water to form HCl, the HCl is introduced into the standing device to react with sulfide in a mixture to generate hydrogen sulfide, hydrogen sulfide gas generated after the reaction enters an air inlet of a spray tower through an air outlet II, a solid-liquid mixture after the reaction is conveyed to a solid-liquid separation device, the mixture is separated from liquid containing heavy metal ions in the solid-liquid separation device, the liquid (ZnS and FeS solution slightly soluble in acid) is used for electrolytic treatment, and high-valence heavy metals are converted into zero-valence state and separated out through oxidation-reduction reaction of an electrolytic cell; the solid mixture contains heavy metal chelate and metal sulfide precipitate, the solid mixture and the tail gas enter the tail gas treatment device, and the tail gas is absorbed by the absorbent in the tail gas treatment device and the solid is discharged because the absorbent in the tail gas treatment device has high adsorbability and stability. The process meets the requirement of stabilization process circulation, realizes high-efficiency removal of heavy metal ions in tailings, can greatly reduce leaching toxicity of heavy metals under acidic conditions, and effectively improves stability of the heavy metal ions.

Compared with the prior art, the invention has the following advantages and effects:

(1) The stabilization process provided by the invention can realize heavy metal pollution treatment of tailings after mining activities, can effectively remove the heavy metal pollution under an acidic condition, does not generate oxyhydrogen precipitation, and recycles hydrogen sulfide gas, thereby reducing sulfate generated in the recycling process, reducing the treatment engineering quantity and cost of hazardous wastes, effectively treating toxic and harmful hydrogen sulfide gas generated by industrial mining activities and the like, and having a great potential technical application prospect.

(2) The heavy metal treated by the method is discharged in the form of chelate or metal sulfide precipitate to reach a stable state. The separated metal can be recycled, and certain economic benefit is achieved.

drawings

FIG. 1 is a schematic view of the apparatus of the present invention;

In the figure: 1-a spray tower; 2-a soaking device; 3-a stirring device; 4-a standing device; 5-a solid-liquid separation device; 6-tail gas treatment device; 7-a feed inlet; 8-vacuum pump-pumping machine; 9-gas outlet II; 10-liquid inlet; 11-an air inlet; 12-gas outlet I; 13-a discharge hole; 14-a lift pump; 15-electrolysis unit.

Detailed Description

The present invention will be described in detail with reference to the following embodiments, but the scope of the present invention is not limited to the above-described embodiments.