The ore hardness is 12~14, and the rock hardness is 8~10. The ore density is 3.1~3.2t/m 3 and the rock density is 2.7 t/m 3 . The looseness coefficient of ore and rock is 1.5. The ore humidity is generally 0.1 to 0.2% and the maximum is 0.38%. (3) Major technical improvements since the plant was put into production: Changxing Mingwang Rubber & Plastic Technologies Co.,Ltd. , https://www.cxmingwang.com
(2) Process flow: The crushing and screening process of the plant is shown in the following figure. 1. The process of mineral processing is shown in Figure 2 below. The data in the figure is taken from the results of the new three series process in September 1980. 
1) The operating speed of the heavy-duty plate feeder is increased from 0.05m/s to 0.058m/s, and the ore supply is increased from 1200t/h to 1300t/h, meeting the expansion requirements.
2) Change the rolling wall of the fine crusher to the medium crusher to reduce the product size of the crusher. The fine crusher discharge port is changed from 15mm to 10mm, and the fine crushing cycle load is reduced from 116% to 100%. Below 12mm, the ball mill processing capacity is increased by 0.94t / (unit.h), and the ball mill electromechanical consumption is reduced by 0.22kw.h / t according to the original ore.
3) Improve equipment maintenance work. In 1984, the ball mill operation rate reached 94%.