The stale garbage contains a lot of hydrogen and sulfide gas, methane, carbon dioxide, carbon monoxide gas, harmful heavy metal elements, pathogenic bacteria, parasitic eggs and other toxic and harmful substances, which must be properly treated before the next step of construction.

Pretreatment is one of the key points of this technology. The pretreatment work is not well done, the follow-up work cannot be carried out or the progress is slow, and even brings potential safety hazards and environmental pollution.

The main method of this technology is to use special equipment, drill holes densely in different areas on the garbage dump, and inject special microbial agents at the same time. After several hours of excavation, there will be no toxic and harmful gas, no odor, no impact on the surrounding environment due to construction, and no harm to construction personnel.

Conventional and special mechanical equipment are used to screen the excavated garbage with sorting equipment. The material under the screen is mainly humus soil (hereinafter referred to as humus soil), accounting for more than 50% of the total amount. The materials on the screen account for about 50% and are sorted into combustible and incombustible again, accounting for about 6:4. Multi grade sorting may also be carried out according to different conditions. Different garbage dumps and different locations of the same garbage dump have different proportions of materials.

In view of the characteristics that there are many construction wastes and large pieces of garbage in the stale garbage, the automatic sorting equipment for large pieces is adopted to reduce the labor cost;

In view of the characteristics of high moisture content of stale garbage, special equipment structure design, multi-level sorting, reduce equipment failures and improve sorting efficiency;

In view of the large amount of broken glass in the aged garbage, the structure of the disc screen disk was improved to reduce the frequency of material jamming and shutdown;

In view of the adhesive characteristics of plastic soil in the stale garbage, improvements have been made in the aspects of air separation classification, air flow layout and vibration homogenization, which have improved the efficiency and quality of air separation.