Ash water treatment system in coal gasification process

The utility model provides a grey water treatment system in a coal gasification process, which is provided with a scale inhibition dispersant tank, and an outlet of the scale inhibition dispersant tank is provided with a scale inhibition dispersant pump. A first dispersing agent pipeline, a second dispersing agent pipeline, a third dispersing agent pipeline and a fourth dispersing agent pipeline are arranged at an outlet of the scale inhibition dispersing agent pump; the first dispersing agent pipeline is communicated with the overflow pipeline between the clarifying tank and the grey water tank, and the communication point is close to the clarifying tank; the second dispersing agent pipeline is communicated with an inlet of the low-pressure grey water pump; the third dispersing agent pipeline is communicated with an inlet of the deoxygenated water pump; and the fourth dispersing agent pipeline is communicated with an inlet of the high-temperature hot water pump. According to the utility model, the scaling sp