Improved impurity removal device used before lime mixed-loading

The invention provides an impurity removal device used before lime mixed-loading. The impurity removal device comprises a material screening pipeline, a material storage bin and an impurity storage bin, wherein the material screening pipeline is designed to be a vertically-arranged spiral pipeline or a snakelike bent pipe; a mesh screening plate laid in the length direction of the material screening pipeline is arranged in the material screening pipeline; the inner cavity of the material screening pipeline is divided by the mesh screening plate into a first channel and a second channel; the top opening of the first channel is used for feeding; the bottom opening of the first channel is connected with the impurity storage bin; the sectional area of the first channel is gradually reduced from the top to the bottom; the top of the second channel is sealed; the bottom opening of the second channel is connected with the material storage bin; and the sectional area of the second channel is gradually increased from