In the view of the situation of the efficient grader in Panzhihua iron and steel company,which have hard operations,delaying action and changeable technological parameter,we have designed a control system to realize the auto regulation to the puple density.

Key links such as mill\'s feed qty control,mill\'s inlet water qty control and mill\'s grinding density of the system are explained in details.

It's not satisfied with the convertional PID control because of the frequent fluctuation of the pulp consistency resulting from the high nonlinearity of the mineral grinding process and the random disturbances,hence, a neural network PID controllor is designed to control the pulp consistency.

It s not satisfied with the convertional PID control because of the frequent fluctuation of the pulp consistency resulting from the high nonlinearity of the mineral grinding process and the random disturbances,hence, a neural network PID controllor is designed to control the pulp consistency.

The questions of low ore treating ability,big fluctuation of concentrating indexes,low filtering feed ore concentration,etc,are existed in old magnetic concentration process flow of concentrating mill of Jinling iron mine.