The ore depletion reasons analysise of sub-level caving method;

Through founding the mathematics model in which the profit is aim function and depletive rate is independent variable, the effect of ore depletion on mine's economic benefit is analyzed quantitatively In order to control and decrease the ore depletion, the technology of geology and mining should be strengthened, and also with the field managemen

The effects of diluting phosphate rock on the production of WPA is simply discussed and some technical countermeasures for diminishing the adversity:chemical Mg removal treatment before wet milling,cyclone separation of phosphogypsum before filtering,adding phosphate rock powder into diluted phosphoric acid,yielding extra phosphorus.