The stirring tank is divided into two types: single-blade stirring and multi-blade stirring. The tank body is cylindrical, and the bottom of the tank is spherical or flat. There is a circulation drum in the center, and the agitator is installed in the lower part of the circulation drum. The tank body is usually made of carbon steel lined with acid-resistant bricks. The agitator has paddle type, propeller type, anchor type and pulley type.