Problems, characteristics, and related requirements of wastewater treatment in open-pit coal mines

1. Common problems in sewage treatment.

(1) The system cannot achieve the separation of rainwater and sewage due to water inflow. During the rainy season, a large amount of coal powder and sediment enter the system, and there are no pre-treatment sections such as regulating tanks and sedimentation tanks at the front end of the system. The water quality and quantity fluctuate greatly, which has a significant impact on the biochemical system and seriously affects the treatment effect.

(2) The oily wastewater from the maintenance workshop in the mining area enters the system after passing through the oil-water separator. The oil in this part of the oily wastewater is mostly emulsified oil, and the oil-water separator mainly has a good removal rate for floating oil, but the removal effect on emulsified oil is poor, making it difficult to achieve sufficient oil-water separation.

(3) The sewage from the coal mine canteen is directly discharged into the sewage treatment system without oil separation, causing frequent blockages in the sewage pipes and affecting the quality of the incoming water.

2. Characteristics and processing related requirements.

        From a qualitative perspective, the water quality of open-pit coal mine wastewater is highly similar to that of general urban wastewater, but there are significant differences between it and urban wastewater. Its characteristics are mainly reflected in the following aspects: relatively large fluctuations in water quality and quantity, relatively low pollutant concentration, relatively good biodegradability of wastewater, and relatively low treatment difficulty. Generally speaking, there are significant differences in the effluent requirements of open-pit coal mines with different scales. This requires certain standards for the wastewater treatment process of coal mine treatment plants, requiring them to use relevant national environmental protection department regulations as evidence to clarify the water quality treatment effect and fundamentally guarantee the effluent quality.