METHOD FOR CLEANING SOIL FROM ORGANIC SUBSTANCES Russian patent published in 2022 - IPC B09C1/06 

FIELD: soils cleaning.

SUBSTANCE: invention relates to methods for cleaning soils from organic substances represented by gasolines, diesel fuel, mineral, synthetic and semi-synthetic oils in the event of spills and leaks by applying heat treatment, and can be used in the field of environmental protection at the facilities of the mineral resource complex. A method for cleaning soil from organic substances, which includes supplying matrix material contaminated with organic substances to the inlet end of an indirectly heated rotary kiln so that the material is moved by the rotary kiln from the inlet end to the discharge end, unloading the material from the discharge end of the kiln practically free of hazardous organic substances. At the same time, the borders of the potential territory of contamination with organic substances, represented by gasolines, diesel fuel, mineral, synthetic or semi-synthetic oils, are first identified, and then the type of organic matter is identified at the place of the spill or leak. Next, sampling is carried out and the content of pollutants in them is determined on the spectrometer, the average content of pollutants is determined by dividing the sum of the values ​​of the content at the sampling points by the number of points, the content of organic carbon in the soils, which are selected in the background non-contaminated area, is determined by multiplying by a factor of 1.724, the layer of contaminated soil is remove and transported to the place of temporary storage. The rotary kiln drum is heated by radiation and convection from electric heating elements, which are made in the form of spirals, the contaminated soil is thermally treated, the residual content of pollutants is monitored on the spectrometer, after that the cleaned soil is delivered to the place of withdrawal and mixed with humus. At the same time, for soils with a gasoline content of 1001 to 39100 mg/kg, heat treatment is carried out at a temperature of 150 to 160 ° C for 210 to 220 minutes, for soils with a gasoline content of 39,100 to 200,000 mg/kg, heat treatment is carried out at a temperature of from 200 to 210°C for 200 to 210 minutes, for soils with a diesel content of 1001 to 3100 mg/kg, heat treatment is carried out at a temperature of 150 to 160°C for 210 to 220 minutes, for soils with diesel fuel from 3100 to 6200 mg/kg, heat treatment is carried out at a temperature of 200 to 210 ° C for 230 to 240 minutes, for soils with a diesel fuel content of 6200 to 11500 mg/kg, heat treatment is carried out at a temperature of 250 to 260 °C for 170 to 180 minutes, for soils containing mineral, synthetic or semi-synthetic oils from 1001 to 2100 mg/kg, heat treatment is carried out at a temperature of 200 to 210°C for 260 to 270 minutes, and for soils with content mineral, synthetic or semi-synthetic oils from 2100 to 3800 mg/kg heat treatment is carried out at a temperature of from 250 to 260°C for 300 to 310 minutes.

EFFECT: method ensures the purification of the soil from organic matter while retaining part of the humus.

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