Find a good "place" for chemical waste salt

As an important part of the national economy, while the chemical industry has contributed a huge economy, it will inevitably bring wastewater, waste gas and solid waste emissions. There is a solid waste that generates more than 10 million tons per year, and it is quite tricky to deal with, that is -waste salt.

At the Green Development Conference of the fine chemical industry and the seventh chemical industry hazardous waste and waste salt treatment forum held from August 25th to 26th, experts and scholars started a heated discussion on the "place" of waste salt. How to scientifically identify the harmful components in waste salts, how to achieve standardized management, and how to make reasonable resource utilization, have become the hotspot of the conference.

The industry's annual production waste salt exceeds 10 million tons -the cost of disposal is difficult and difficult

According to statistics, the total amount of waste salt in the chemical industry exceeds 10 million tons/year, which is mainly concentrated in fine chemical industries such as pesticides, chemicals, dyes, and rubber aids.

Why does it produce so many waste salt? Zhou Zhengsheng, chief engineer of Jiangsu Lansheng Chemical Environmental Protection Co., Ltd., said that there are three main reasons: First, some enterprises have low production technology content and aging equipment, resulting in low raw material utilization and large loss consumption. Some raw materials are discharged into the environment in the form of "three wastes"; the second is that some enterprises have one -sided pursuit of product quality and ignore the environmental quality; third, some companies have the phenomenon of "running, counterfeiting, dripping, leakage".

"Specifically, 1.2 ~ 7 tons of waste salt can be produced per ton of dyes; 1 tons of rubber auxiliary agent can produce 0.5 ~ 1 tons of waste salt; producing 1 tons of pesticides can produce 0.2 to 2 tons of waste salt." Dr. Hou Songxuan, a chemical hospital test technology Co., Ltd., said that the treatment of waste salt is a headache for industry companies. One is because it has a wide range of sources and large specificity; the other is because it has a large amount of production, the components are complex, and the processing is difficult.

Hou Songxuan pointed out that waste salt has the characteristics of high water -soluble, and it has higher anti -seepage requirements for landfills, and when its solubility exceeds 10%, it can only be rigid landfill. In this way, even the general waste salt is basically equivalent to the disposal cost of hazardous waste. If the incineration method is adopted, the reduction effect can be achieved for waste salt. At the same time, under high temperature melting conditions, waste salt will cause corrosion to steel equipment such as incineration furnaces, further increasing the difficulty and cost of incineration.

"Although chemical waste salt is not included in the" National Dangerous Waste List ", in fact, many waste salt is distinguished by dangerous waste after identification." Wei Honglian, chief engineer of the Solid waste and Chemical Management Technology Center of the Ministry of Ecology and Environment About 80%of the stacked waste salt is mixed with salt. Due to the high disposal costs and low market recognition, waste salt cannot find a suitable way out. Only a large number of piles can exist in the enterprise, bringing a large environmental risk.

In this context, the resource and utilization of waste salt is used to find a good "place" and become a compulsory course for the chemical industry.

The premise of resource utilization -evaluation and control of harmful impurities

Insiders believe that to find a good "place" for waste salt, we must first evaluate and control the harmful impurities. Because among the waste salt produced by many companies, by -products, intermediates are often mixed with harmful impurities, which is difficult to distinguish. Only by identifying and removing these harmful impurities as hazardous wastes can we better achieve comprehensive utilization.

"In the case of waste salt difficulty governance, how to achieve controllable resource utilization is a problem that must be considered. And the assessment and control of harmful impurities have become the prerequisite for resource utilization." Hou Songxuan said that for the disposal of waste salt, dangerous dangerousness is dangerous. The main problem of waste identification is: What are the harmful impurities and how much is there? What indicators do I need to control? Is the control indicators reasonable?

Specifically, the traceability analysis of harmful impurities must be performed, including the analysis of the traceability of production raw materials, the analysis of the source of production process, and the analysis of the targeted efficiency of harmful impurities in the process of harmless treatment. Harmatic impurities components. Secondly, the control indicators of harmful impurities should be performed, including downstream utilization channels, exposure evaluation of scenarios, and impact on the environment and human health.

Fang Wenjie, deputy general manager of the Environmental Technology Co., Ltd. of Zhejiang Chemical Technology, pointed out that the identification indicators of hazardous waste should include flammable, corrosive, reactivity, acute toxicity, immersion toxicity and toxic substance content. Therefore, in the process of identification, the process of raw materials, products and by -products, and waste salt should be performed in a comprehensive and in -depth analysis of the toxicity of all substances related to waste salt to eventually determine the harmful components that need to be identified.

"The identification of hazardous waste will provide technical support for the comprehensive utilization of scientific management and healthy environmental risks of waste salt." Guo Jing, manager of the department of testing technology Co., Ltd., Shenyang Shenhua Institute, said that the identification of hazardous waste is not only It can provide technical support for environmental protection, public security, emergency and other departments, and can also provide environmental health risk assessment data for the formulation of group standards, and provide reference for the setting of waste salt index limit and finding comprehensive utilization channels.

Comprehensive use of shortcuts -recycling "price" objects

"There are many" prices' in waste salt. "Ou Yunchuan, deputy general manager of Shenyang Huiyu Chemical and Environmental Technology Co., Ltd., said that, such as raw materials that have not been fully reacting, the solvents that have not participated in the reaction, the intermediate and product generated by the reaction generation, There are "valence" objects produced by the side reaction, and there are "valence" objects produced with the pharmacy reaction, and various inorganic salts. Among them, some substances have great recycling value and resource potential. After comprehensively considering factors such as investment, income, and the complexity of the recycling process, choosing the appropriate method to recycle "price" objects is a shortcut for comprehensive use of waste salt resources. Zhou Zhengsheng said that the key to the use of waste salt resources is the effective combination of advanced technologies at home and abroad, the innovation and upgrading of processes, and in -depth cooperation between governance enterprises and emission enterprises.

Shang Wenjun, deputy general manager of Jiangsu Taurus Environmental Protection Engineering Equipment Co., Ltd. introduced the innovative technology combined with the combination of waste salt thermal oxidation and oxidation of waste salt oxidation and harmless treatment, which is essentially the integration of waste salt utilization and treatment processing process. Essence This technology breaks through the bottlenecks that affect the long -term stable operation of engineering devices such as salt -hanging walls and blocking during the waste salt incineration process, and realize the comprehensive resource use of waste salt. During the process of processing, recyclable sodium chloride, mixed salt, steam and other recyclables, as well as high -value products such as chlorine, alkaline, hydrogen, hydrochloric acid, and sodium hydrochloride.

Many people in the industry also believe that the "point -to -point" orientation is a good way to achieve comprehensive use of waste salt. The so -called "point -to -point" directional utilization is the dangerous waste generated by a unit, which is used as an environmental governance raw material for environmental governance or industrial raw material production as another hazardous waste treatment unit. In the "Implementation Plan for Strengthening the Supervision and Disposal Capability Reform of Dangerous Wastes" issued by the General Office of the State Council in 2021, it clearly proposes to improve the work requirements of the "point -to -point" directional utilization management.

"Exploring hazardous waste 'Point -Points' targeted use and the sharing of disposal facilities within the group is one of the important ways to really make dangerous wastes go." Wei Honglian talked.

"The" point -to -point "directional utilization can achieve a win -win situation for environmental and economic benefits." Zheng Fanyao said that after the "point -to -point" directional use of "point -to -point" is carried out, it not only improves environmental benefits, but also saves more than 15 million yuan of treatment and disposal costs each year.

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