Study On Runoff And Sediment Yield Mechanism Of Different Reclamation Slopes In Dry Iron Tailings

50 Iron tailings are the main component of industrial solid waste with loose structure and steep slope.The erosion is serious to cause huge ecological problems,and at the same time result in serious economic losses and social impacts.However,the research on the reclamation and erosion mechanism of iron tailings is relatively rare.In this study,the iron tailings reservoir of Quanzigou,Yuqu County and Yuncheng City,Shanxi Province was taken as the research object,and the mechanism of runoff and sediment yield of different reclamation slopes of iron tailings was studied.On the basis of field investigation,using artificial rainfall s imulation technology,different reclamation slopes(Loose Tailings,LT;Crusty Tailings,CT;Tailings Incorporating Mushroom Residue,TM;Tailings Incorporating Soil and Mushroom Residue,TSM;Tailings Incorporating Soil,TS;Soil,S)and different rainfall intensity(60,90,120 mm/h)and different slopes(25,30,35°)were analyzed.characteristics of runoff and sediment yield and slope hydrodynamic mechanism to clarify the mechanism of runoff and sediment yield on different reclamation slopes in iron ore tailings.The main findings were as follows:(1)Under the same slope condition,the slope runoff showed an increasing trend with the increase of rain intens ity,but with the increase of rain intensity,the increase of slope runoff decreased.Under the same rain intens ity condition,the slope was not the dominant factor in the runoff of the slope,and the type of slope matrix had a greater impact on the runoff of the slope.The effect of rain intensity on the sediment yield of each substrate type slope was different depending on the type of matrix.The effect of slope on sediment yield on slope was different due to different rain intensity.(2)Compared with LT slope surface,TS reclamation slope had no obvious effect on reducing runoff erosion and sediment yield,while TSM,S and TM reclamation slopes had certain effects on reducing slope erosion and sediment yield,among which The best sand effect was the TM slope,which performs best under all grade conditions.Compared with the LT slope,the CT and S slopes had obvious effects on the slope reduction.The flow reduction effect of the TSM slope gradually deter iorates with the increase of the rain intensity,while the TM and TS slopes reduce the flow effect.Not obvious,even the increase in production flow.(3)The rain intensity was positively correlated with the Reynolds number and the Froude number of the runoff,and the Reynolds number and the Froude number were less affected by the slope.The slope runoff of each matrix type was a laminar flow.Under different slope conditions,the runoff states of the slopes except TM,TSM and TS were slow-flow,and the runoff states of other reclamation slopes were rapids.There was a negative correlation between the rain intensity and the runoff resistance coefficient and the roughness coefficient.The slope runoff resistance coefficient and the roughness coefficient were positively correlated with the slope.There was a significant positive correlation between the sediment transport rate and the Reynolds number and the Froude number(P<0.01),and the correlation with the drag coefficient was not obvious,and it was significantly negatively correlated with the roughness coefficient(P<0.05).(4)The relationship between rain intensity and slope runoff shear force was not obvious.The slope runoff shear force decreases first and then increases with the increase of slope.Rain intensity was positively correlated with runoff power and has no significant correlation with slope.The sediment yield of slopes of different matrix types had a cubic function relationship with runoff shear force,and was a power function relationship with runoff power.The correlation between runoff power and sediment yield on the slope can be used to calculate the slope erosion and sediment yield of each matrix type.