Grader mother liquor adding self-pressing device and using method thereof

The invention belongs to the technical field of metallurgy and chemical engineering, and particularly relates to a grader mother liquor adding self-pressing device. The device comprises a first decomposition tank, a second decomposition tank, a third decomposition tank, a fourth decomposition tank, a fifth decomposition tank, a sixth decomposition tank, a seventh decomposition tank, an eighth decomposition tank, a ninth decomposition tank and a second decomposition tank which are communicated through pipelines, the mutually communicated decomposition tanks are arranged in a U shape, and the first decomposition tank and the second decomposition tank are arranged in the same direction. A vertical disc filter is arranged at the top of the first decomposition tank, a liquid seal tank is arranged at the top of the ninth decomposition tank, the vertical disc filter is connected with the liquid seal tank through a liquid inlet pipe, and the liquid seal tank is communicated with an inlet of a feeding pump of a grader