| The slime is the waste of bauxite during the process of alumina production,which belongs to alkaline harmful residue.At present,domestic tailings treatment mainly concentrated in wet discharge and dry stacking,resulting in a large number of tailings accumulation.This not only wastes a large amount of scarce mineral resources,occupies a lot of land resources,but also seriously threatens the sustainable development of the mine industry and brings great harm to the natural environment and human society.Therefore,it is of great significance to accelerate the sedimentation of mud to reduce the amount of mud heap,improve the service life of sludge storage,and reduce the leakage risk of the mud dump.In this paper,through field tests and laboratory geotechnical tests,it is found that the undisturbed slime in the washing workshop of Pingguo Aluminum plant has a large fluctuation in water content,between 540.91%~1305.51% and 7.11%~15.60%,The proportion is 2.74,the plastic index is 25.56,the liquid Index is 33.76,the slime is mainly sticky grain(d≤0.005mm),which accounts for 66.5%.by X-ray phase analysis,it is found that the elements are mainly aluminum,iron,silicon and calcium.The main mineral composition is a water hardening aluminum,Sanshui aluminum,kaolin,hematite and other clay minerals,mud ph value of 7.6,partial alkaline,potential value of-19.0695 MV.The FE element in the mud is more six-square structure of the iron ore and oblique structure of the needle iron ore form,in the mineral material phase weight of the larger proportion,can be judged in the mineral mud ore powder washing ore residue after treatment.In this paper,the effect of external environmental factors on the sedimentation of slime was designed,and the sediment test of five factors,such as concentration,ph value,temperature,flocculant and electric field,was carried out,and the best sample preparation method was found by comparing four kinds of reconstructed specimen.It was found that the sedimentation effect of five factors from big to small is: flocculant > electric field,concentration >ph value ≈ temperature.Flocculant polyacrylamide for the sedimentation of 10% of the settlement effect of 0 boundary point,polyacrylamide can not be completely with the mud particles reaction,the sedimentation of mud less impact,the addition of more than 0 boundary point will have flocculation effect(the best concentration of 0.05%~ 0.1%).Based on the theory of Flocculation and electrophoresis,the sedimentation mechanism of flocculant and the mechanism of electric field action are obtained.When enough Pam polymers and particles are connected to form larger floc,if the amount of polyacrylamide input exceeds the optimal concentration,a "spring" effect is formed,that is,the concentration of the polyacrylamide is increased,and the final sediment concentrations drop.The influence factors of electrophoresis were analyzed,the influence of electric field on settlement was explained,and the effect of electric field on colloidal impurity and suspended impurity was condensed and precipitated.The anode metal electrode will be electrolytic corrosion in the applied electric field,forming the hydroxyl complex,and the particles are gathered together into a chain to form a bridging function.The applied electric field also affects the velocity and the final concentration of the mud settling,and when the applied electric field is higher than 13.7V,the settling velocity and the final concentration of the mud are increased linearly.In this paper,the factors of external factors to the sedimentation of the mud,the most important factors,and the settlement principle of the mud under different control factors are studied in detail,which provides a reference value for the technical design of the mud settling process,which provides a theoretical basis for the establishment of the constitutive equation of the multi-factor mud... |
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