1. Technical name:Rapid leaching classification technology and equipment for contaminated soil

2. Usage industry:Environmental resources field, soil remediation industry

3. Scope of application and main technical indicators: It can be used to treat sandy soil containing heavy metals, polycyclic aromatic hydrocarbons and combined pollution of heavy metals and polycyclic aromatic hydrocarbons. Main technical indicators: (1) In the original soil, the mass ratio of clay components below 60μm to the original soil is less than 40%. (2) More than 95% of the main pollutants in the original soil adhere to the surface of the gravel but do not penetrate into the gravel. (3) The maximum processing capacity reaches 60t/h, can operate continuously for 24 hours, and the total power is 800 kW.

4. Technical content

Taking advantage of the fact that pollutants in the soil are generally concentrated in smaller particle size components, the pollutants are separated and separated from the surface of hard gravel through leaching techniques such as strong mud removal, fine screening and efficient solid-liquid separation. The separated contaminated soil can be obtained. Grade 7 particle size components: 100 mm, 10~100mm、2~10 mm、1~2 mm、250 μm~1 mm、60 μm~250 mm、<60 μm。After soil leaching, the concentration of soil pollutants in most particle size components reaches the standard, and the pollutants are enriched and concentrated into the mud cake for subsequent disposal, thereby reducing the amount of contaminated soil.

After treatment of contaminated soil, the reduction will reach more than 90%, the pollutant removal efficiency will not be less than 85%, and the treatment cost per ton of contaminated soil will be 300-350 yuan.

5. Energy conservation and greenhouse gas emission reduction effects

The use of rapid leaching technology for contaminated soil will increase the moisture content of the mud cake by about 10%, but compared with the direct use of thermal desorption technology, this technology reduces the amount by about 90%. For 10000 tons of contaminated soil, the direct use of thermal desorption technology requires 1 million standard cubic meters of natural gas. After adopting the rapid leaching technology, the concentrated mud cake is then subjected to thermal desorption treatment, and only 200,000 standard meters of natural gas needs to be burned. Therefore, using rapid leaching technology for every 100,000 square meters of contaminated soil can reduce CO emissions by about 800,000 square meters.₂。

6. Demonstration and application promotion

(1) Demonstration site: A pilot demonstration project was completed at an industrial legacy site contaminated by heavy metals and polycyclic aromatic hydrocarbons in Dalian. The treatment results met the site restoration acceptance standards. The maximum amount of contaminated soil treated by leaching equipment was 20 t/h, and the treatment cost per ton of contaminated soil was 300-400 yuan; Engineering verification was completed at a contaminated site in Haibei, Qinghai, and the treatment results met the site restoration acceptance standards. The maximum contaminated soil treatment capacity can reach 28t/h, and the cumulative treatment of contaminated soil is about 10,000 tons. The treatment cost per ton of contaminated soil is further reduced to 300-350 yuan.

(2) Application promotion venue: 2015~In 2016, at a steel site in Liwan District, Guangzhou, this technology was used to treat 320,000 tons of soil contaminated by polycyclic aromatic hydrocarbons and heavy metals; in 2016~In 2017, at a steel site in Dadukou District, Chongqing, this technology was used to treat 60,000 tons of soil contaminated by polycyclic aromatic hydrocarbons and heavy metals;(3) 2017~In 2018, at a school site in Ganjingzi District, Dalian, this technology was used to treat 140,000 tons of heavy metal-contaminated soil;(4) 2017~In 2018, in a sediment project in the Loushan River in Qingdao, this technology was used to treat 120,000 tons of heavy metal-contaminated soil.

7. Estimation of investment and operating costs

Taking a 60t/h contaminated soil leaching classification equipment as an example, the investment and operating costs are estimated to be 2,500~30 million yuan, and the treatment cost per ton of contaminated soil is 300-350 yuan (including operation and maintenance expenses).

8. Investment payback period

Taking a 60 t/h contaminated soil leaching classification equipment as an example, it is estimated that there is 200 days of operation every year, the comprehensive profit per ton of contaminated soil treatment is 50 yuan, and the investment payback period is 20~24 months.

9. Prospects for achievement transformation and promotion

This achievement is still in the partial promotion stage, and its application and promotion prospects are broad. It is expected that the penetration rate will reach 3% by the end of the 13th Five-Year Plan.