The Ore Dressing Plant is located in the southeast of Liaoyang City, Liaoning Province, which is its Group the earliest Ore Dressing Plant using Auto-control system for the Entire Process, it with an annual ore processing capacity of 12 million tons, concentrate grade of 67.70% and tailing grade of 9.00%. In 1996, the company succeeded in implementing an ore grinding automation control system, which created huge economic benefits for the enterprise. The ore dressing plant adopts such a crushing flow as dry selection and rock abandoning after medium crushing in three sections and one closed circuit. The eventually crushed product size is -12mm accounting for 90%. There are five grinding & dressing series in the ore grinding, and the designed capacity of mill is 290t/h.The first grinding process adopts 5.03×6.7m overflow type ball mill, and the first overflow particle size is -200 mesh, which accounts for about 55%; the second grinding process adopts 4.0×7.5m overflow type ball mill, and the second overflow particle size is -200 mesh, which accounts for about 85-90%; the third grinding process adopts 2.7×3.6m overflow type ball mill, and the third overflow particle size is -200 mesh, which accounts for 90-95%. The automation control system adopts advanced DCS control system to realize centralized control of whole plant, ensure production quality and optimize production index. High-precision online detection & analysis instruments, stable control equipment and advanced control software are used at site, which can determine the mill load and ore properties according to the site process conditions, and can achieve optimal control of the mill ore feeding and water supply quantity. Under the condition of ensuring product quality, combined with particle size and grade online detection instruments can realize the optimal control of whole process, which reducing the labor intensity of workers, stabilizing the concentrate index, improving metals recovery rate, and greatly improving the economic benefits of processing plant.