阅读说明：本技术 一种无害化处理后的废汞触媒活性炭的再生方法 (Regeneration method of waste mercury catalyst activated carbon after harmless treatment ) 是由 李海龙 杨琴 张明光 杨建平 屈文麒 于 2019-09-11 设计创作，主要内容包括：本发明公开了一种无害化处理后的废汞触媒活性炭的再生方法,属于废汞触媒的回收再利用技术领域。本发明将无害化处理后的废汞触媒中的活性炭先置于盐酸溶液中振荡,盐酸溶液浓度为0.2~0.8 mol/L,振荡时间为0.5~4 h；过滤后置于隔氧环境中升温至650~850℃,维持0.5~4 h,冷却得到再生活性炭。本发明提供的化学再生与热再生相结合的处理工艺所需设备简单,再生时间短,再生效果好,采用较低成本即可实现废汞触媒中活性炭的再生利用,具有明显的经济效益与环保意义。(The invention discloses a method for regenerating activated carbon of a waste mercury catalyst after innocent treatment, which belongs to the technical field of recycling of the waste mercury catalyst.A hydrochloric acid solution is put into the activated carbon in the waste mercury catalyst after innocent treatment for oscillation, the concentration of the hydrochloric acid solution is 0.2 ~.8 mol/L, the oscillation time is 0.5 ~ h, the activated carbon is put into an oxygen-isolated environment after being filtered and heated to 650 ~ ℃ for 0.5 ~ h, and the regenerated activated carbon is obtained after cooling.)

1. A regeneration method of waste mercury catalyst activated carbon after innocent treatment is characterized by comprising the following steps:

(1) placing the harmlessly treated waste mercury catalyst activated carbon into a hydrochloric acid solution with the concentration of 0.2 ~ 0.8.8 mol/L, and oscillating by using an oscillator for 0.5 ~ 4 h;

(2) filtering and separating the mixed solution obtained in the step (1) to obtain filtrate and activated carbon, and returning the filtrate to the step (1) for recycling;

(3) putting the filtered activated carbon product into a temperature programmed heating furnace, heating to 650 ~ 850 ℃ under the condition of oxygen isolation, keeping the temperature for activation and regeneration for 0.5 ~ 4 h;

(4) and closing the heating furnace for cooling to obtain the regenerated activated carbon.

2. The method for regenerating the harmlessly treated waste mercury-catalyzed activated carbon as claimed in claim 1, wherein in the step (1), the mass ratio of activated carbon to hydrochloric acid is 1:5 ~ 1: 10.

3. The method for regenerating the harmlessly treated waste mercury-catalyzed activated carbon as claimed in claim 1, wherein the hydrochloric acid concentration in the step (1) is 0.4 ~ 0.8.8 mol/L, and the oscillation time is 0.5 h.

4. The method for regenerating the harmlessly treated waste mercury-catalyzed activated carbon as claimed in claim 1, wherein in the step (1), the oscillator is a roll-over oscillator with a frequency of 20 ~ 50 rpm.

5. The regeneration method of the harmlessly treated waste mercury-catalyzed activated carbon according to claim 1, wherein in the step (2), the activated carbon is separated from the hydrochloric acid solution by using a polypropylene or polytetrafluoroethylene corrosion-resistant filter plate, then dilute sulfuric acid is added into the waste hydrochloric acid solution to remove calcium chloride generated by the reaction, the calcium chloride is separated again, and finally the filtered hydrochloric acid solution is returned to the step (1) for reuse.

6. The method for regenerating the harmlessly treated waste mercury-catalyzed activated carbon as claimed in claim 1, wherein the temperature in the step (3) is 700 ~ 750 ℃, and the regeneration time is 2 ~ 2.5.5 h.

Technical Field

The invention belongs to the technical field of recycling of waste mercury catalysts, and particularly relates to a regeneration method of harmless treated waste mercury catalyst activated carbon.

Background

The mercury catalyst is an indispensable part for producing polyvinyl chloride (PVC) by a calcium carbide method, and is used as a catalyst for synthesizing Vinyl Chloride (VCM) by acetylene and hydrogen chloride gas in PVC production. The mercury catalyst is produced by taking activated carbon as a carrier and mercuric chloride as an active substance, and loading the mercuric chloride on the surface of the activated carbon. After the mercury catalyst is used for a certain period of time, the activity of the mercury catalyst is reduced and the mercury catalyst needs to be replaced, and the replaced waste mercury catalyst still contains about 2-5% of mercuric chloride. The mercuric chloride is extremely toxic, extremely volatile and easily soluble in water, and if the replaced mercury catalyst is directly discarded or stacked, serious mercury pollution is caused, and great potential safety hazards are generated. According to the "treatment and disposal method for waste mercury catalyst" (GB/T36382-2008), distillation and oxygen-controlled dry distillation are mainly adopted for the harmless treatment of the waste mercury catalyst at present. The distillation method is characterized in that quicklime, sodium hydroxide and the like are added to convert mercury in each valence state in the waste mercury catalyst into similar substances (most of which are mercury oxide) which are easy to decompose, volatilize and collect and have similar physical and chemical properties, the mercury oxide is heated and decomposed into elemental mercury and oxygen, and elemental mercury vapor is quenched to realize the recovery of mercury in the waste mercury catalyst.

Although the method realizes harmless treatment of the waste mercury catalyst and recovery of mercury, activation and regeneration of activated carbon are not realized, and substances such as quicklime, sodium hydroxide and the like are introduced in a pretreatment process, so that a large amount of calcium carbonate, calcium oxide, sodium carbonate and other powder are attached to the surface of the waste mercury catalyst after a distillation process, the activated carbon is seriously inactivated, and the activated carbon is difficult to reuse. Although the waste mercury catalyst can be treated as general waste in principle after being subjected to harmless treatment of recovered mercury, people always worry about whether the mercury content of a certain batch of activated carbon exceeds the identification standard of hazardous waste. Moreover, the active carbon cannot be recycled, so that serious resource waste is caused, and the production cost of enterprises is increased.

Disclosure of Invention

In order to realize high-value utilization of the waste activated carbon after harmless treatment of the waste mercury catalyst, the invention aims to provide the method for regenerating the waste mercury catalyst activated carbon, which has low cost, simple flow and good effect. The invention utilizes the method of combining the chemical regeneration and the thermal regeneration of the hydrochloric acid to remove calcium carbonate, sodium carbonate, calcium oxide, residual PVC and other substances existing on the surface and inside of the hydrochloric acid, and recovers the adsorption capacity of the activated carbon, thereby realizing the aim of regeneration.

The purpose of the invention is realized by the following technical scheme: a regeneration method of waste mercury catalyst activated carbon after innocent treatment comprises the following steps:

(1) placing the harmlessly treated waste mercury catalyst activated carbon into a hydrochloric acid solution with the concentration of 0.2 ~ 0.8.8 mol/L, and oscillating by using an oscillator for 0.5 ~ 4 h;

(2) filtering and separating the mixed solution obtained in the step (1) to obtain filtrate and activated carbon, and returning the filtrate to the step (1) for recycling;

(3) putting the filtered activated carbon product into a temperature programmed heating furnace, heating to 650 ~ 850 ℃ under the condition of oxygen isolation, keeping the temperature for activation and regeneration for 0.5 ~ 4 h;

(4) and closing the heating furnace for cooling to obtain the regenerated activated carbon.

In the invention, in the step (1), the mass ratio of the activated carbon to the hydrochloric acid is 1:5 ~ 1: 10.

In the invention, in the step (1), the concentration of the hydrochloric acid is 0.4 ~ 0.8.8 mol/L, and the oscillation time is 0.5 h.

In the invention, in the step (1), the oscillator is a turnover type oscillator with the frequency of 20 ~ 50 rpm.

In the invention, in the step (2), firstly, a polypropylene or polytetrafluoroethylene corrosion-resistant filter plate is adopted to separate the active carbon from the hydrochloric acid solution, then dilute sulfuric acid is added into the waste hydrochloric acid solution to remove calcium chloride generated by the reaction, the calcium chloride is separated again, and finally the filtered hydrochloric acid solution is returned to the step (1) to realize the reuse.

In the invention, in the step (3), the temperature is 700 ~ 750 ℃, the regeneration time is 2 ~ 2.5.5 h, and the heating is carried out in a closed oxygen-insulated environment to avoid the loss of the active carbon.

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

1. the method realizes the regeneration of the waste mercury catalyst activated carbon after harmless treatment by adopting a mode of combining chemical regeneration and thermal regeneration, and has the characteristics of good effect, low cost, simple equipment and the like compared with a single activated carbon regeneration method;

2. in the chemical regeneration process, hydrochloric acid is adopted under the oscillation action of an oscillator, substances such as calcium carbonate, sodium carbonate, calcium oxide and the like remained on the surface of the waste mercury catalyst activated carbon can be quickly removed in a short time, and the adsorption capacity of the activated carbon is improved;

3. the method adopts a thermal regeneration mode to regenerate the harmlessly treated waste mercury catalyst activated carbon, quickly removes residual adsorption substances in the activated carbon, and remarkably recovers the adsorption capacity of the harmlessly treated waste mercury catalyst activated carbon.

Detailed Description

The present invention will be further illustrated with reference to the following specific examples. These examples are given solely for the purpose of illustration and are not intended to limit the scope of the invention.

And (3) process screening test:

1. screening of hydrochloric acid concentration and oscillation time

(1) Averagely dividing the harmless treated waste mercury catalyst activated carbon into 20 parts, placing the 20 parts in hydrochloric acid solutions with different concentrations (0.2 mol/L, 0.4 mol/L, 0.6mol/L and 0.8 mol/L), oscillating for a certain time (0.5 h, 1 h, 1.5 h and 2 h), closing the equipment, filtering and drying to obtain the regenerated activated carbon treated under the conditions of different hydrochloric acid concentrations and oscillation time.

(2) The iodine adsorption value and the methylene blue adsorption value of the regenerated activated carbon obtained under different treatment conditions in the step (1) are detected, and the result shows that the regeneration time is constant, when the hydrochloric acid concentration value is increased from 0.2 mol/L to 0.4 mol/L, the iodine adsorption value and the methylene blue adsorption value are both greatly increased, but are not obviously increased after the hydrochloric acid concentration value exceeds 0.6mol/L, when the hydrochloric acid concentration value is in the range of 0.4 ~ 0.8mol/L, the influence of the oscillation time on the adsorption performance of the regenerated activated carbon is small, and the oscillation time of 0.5 h is enough, so that the hydrochloric acid concentration is preferably 0.4 ~ 0.8.8 mol/L, the oscillation time is 0.5 h, the optimum condition is that the hydrochloric acid concentration value is 0.6mol/L, and the oscillation time is 0.5 h.

2. Screening of thermal regeneration temperature and time

(1) Averagely dividing the activated carbon treated under the conditions that the concentration value of hydrochloric acid is 0.6mol/L and the oscillation time is 0.5 h into 12 parts, putting the activated carbon into a temperature programming furnace, setting the temperature to be 650 ℃, 750 ℃ and 850 ℃, treating the activated carbon in an oxygen-isolated environment, keeping the treatment time to be 0.5 h, 1 h, 1.5 h and 2 h, closing equipment after the treatment is finished, and cooling to obtain the regenerated activated carbon treated under different thermal regeneration temperature and time conditions.

(2) The iodine adsorption value and the methylene blue adsorption value of the regenerated activated carbon obtained under different treatment conditions in the step (1) are detected, and the result shows that the adsorption performance of the regenerated activated carbon is firstly increased and then decreased along with the increase of the temperature when the heat regeneration time is fixed, the effect is optimal when the temperature is 750 ℃, the adsorption performance of the activated carbon is increased along with the increase of the retention time when the heat treatment temperature is fixed, the increase amplitude is lower after the retention time is increased and exceeds 2 hours, and the optimal retention time is 2 hours when the time cost and the energy consumption are considered, so that the heat regeneration temperature is 650 ~ 850 ℃, the regeneration time is 0.5 ~ 4 hours, the heat regeneration temperature is preferably 700 ~ 750 ℃, the regeneration time is 2 ~ 2.5.5 hours, and the optimal heat regeneration temperature is 750 ℃ and the retention time is 2 hours.