The Release-migration Mechanism Research Of Phosphorus In The Solidified Body Of Phosphate Waste Rock

With the exisiting phosphate waste rock piles stacked in Shukong Ping phosphate mining area of Xingshan Country in Yinchang City of Hubei Province as the research object,this article bases on the release and migration mechanism of Phosphorus in solidified phosphate waste rock.It combines with continuum mechanics,fluid mechanics,percolation mechanics,discipline basic theory,adapting the methods of laboratory test and theoretical analysis research and revolving round phosphate under the curing effect of phosphorus release-migration mechanism,mading the following work:(1)Using the systematic sampling method to obtain the phosphate rock which is a representative sample in the mineral composition of phosphate ore zone.According to the relevant analysis methods tested,phosphate waste rock basic physical and mechanical parameters are obtained.The mineral group division is dominated by quartz and carbonate,solidified waste rock total phosphorus content range for 1237~1862mg/kg.(2)Based on the macro theoretical basis of Fick's law of diffusion in the fluid dynamics phenomena and Fick's second law to construct the mass transport equations' analytical solution under different conditions,we can push exporting solidified phosphate waste rock's leaching of phosphorus nutrient release amount in release and migration test interval,the leaching flux of phosphorus in leaching interval prime and the formula of phosphorus in pigment accumulation release quantity.It becomes a theoretical foundation of the research which contains the solidified body of phosphate in phosphorus element release-migration texts.(3)Based on the phosphorus release-migration mechanism,a cemented based consolidation of cementitious materials used for controlling phosphorus released from waste rocks was developed.The phosphorus release-migration of solidified waste rocks was evaluated according to U.S.EPA Method 1315 and the phosphorus transport characteristics were quantitatively analyzed.At mean time,the phosphorus released controlling effects were evaluated.The results show that the phosphorus transport during short-term leaching period is dominated by diffusion,while the transport controlled mechanism would change to dissolution during long-term leaching effects.The averge phosphorus observed diffusivity of different solidified phosphate waste rocks is 6.71e-16,which belongs to immobile species.With respect to the field condition,the total phosphorus released from per mass phosphate waste rocks would be reduced from 0.40 mg/kg to 0.25 mg/kg before and after solidification.The released phosphorus reduction extent of solidification management is 37.5%.With a view to evaluating the phosphorus contamination risk from phosphate caving waste rocks during long-term surface deposition to Xiangxi River bay located in Three Gorges.