Reducing the particle size of crushed products is one of the effective ways to reduce energy consumption in concentrators. Dong’anshan Concentrator’s incoming grinding ore particle size is reduced from 20-0mm to 12-0mm, which increases the processing capacity of the ball mill by more than 16%. Dashihe Concentrator’s ore particle size decreased from 15~0mm to 12~0mm. The processing capacity of the ball mill increased by 0.75t, the power consumption decreased by 2.34kW·h/, and the production cost of iron ore concentrate per ton of raw ore decreased by 0.7 yuan. Economical The benefits are obvious. At present, the main measures to reduce the particle size of crushed products are:

(1) Transform the crushing and screening process. For example, the Dagushan Concentrator changed the three-stage open-circuit crushing process to the three-stage-closed-circuit crushing process, so that the particle size of the incoming grinding ore was reduced from 20-0mm to 12-0mm, and the processing capacity of the ball mill was reduced. Increase 3~7i. Dong’anshan Concentrator has transformed the third section and one closed circuit into the fourth section and one closed circuit to further reduce the size of the grinding ore.
(2) Increase the number of fine crushers and the screening area. In Anshan, the content of the -12mm particle size in the finely crushed products has been increased by 5% in the concentrator, and the screening efficiency of the screening equipment has been increased from 41.5% to 80%.
(3) Renovation of crushing equipment, especially the improvement of the lining plate of the secondary crushing and fine crushing. For example, if the rolling wall of the 2100 fine crushing machine is installed on the secondary crushing machine, the parallel area of ​​the lining board of the secondary crushing machine can be lengthened from 170mm to 250mm. , the width of the discharge opening can be reduced from 35~45mm to 20~25mm. By improving the lining plate of the fine crusher, the length of the parallel zone can be lengthened from 250mm to 350mm, and the discharge opening can be reduced from 15~20mm to 12mm.

(4) New crushing equipment such as single-cylinder or multi-cylinder or super-heavy hydraulic cone crushers are adopted. The parallel area length of such crushers, the safety device and the discharge port are controlled by the hydraulic system, which can be adjusted in time according to the wear degree of the lining plate. . For example, the discharge opening of the super-heavy short-head cone crusher used in Midi Concentrator can be adjusted to 6-7mm to ensure the final crushed grain size. Dong’anshan Concentrator has also introduced a superfine crusher to further reduce the particle size of the grinding port.
(5) 4 sets of HP800 cone crushers are installed in the Qidashan Concentrator, so that the -12mm particle size in the grinding material reaches 90%, which realizes more crushing and less grinding, and has significant economic benefits.