| Coal zircon is China’s accumulation of stock and annual increase of the largest industrial waste,a large number of coal zircon emissions and irregular treatment,not only occupy a large number of land resources,but also cause serious environmental pollution.In view of the comprehensive treatment of coltan,a lot of practice and research have been carried out at home and abroad,but the comprehensive utilization rate is still less than 30%,and a resource-based utilization method that can deal with coal zircon in large quantities is urgently needed.The technique of filling and mining by covering rock isolation slurry is to use solid waste such as fly ash and coal mud to fill and extract coal under pressure from buildings and reduce mining technology for mining subsidence disasters.With the popularization and application of this technology,the filling material fly ash is in short supply and expensive,and it is urgent to develop new filling materials.To this end,this thesis comprehensively adopts the combination of experimental testing,theoretical analysis and engineering practical experience to carry out experimental research on the properties of zircon powder filling materials,with a view to developing zircon powder filling raw materials for the cover rock isolation filling mining technology,and using this technology to provide new processing techniques and ideas for the resource utilization of coltan.Firstly,the characteristics of zircon powder material are studied experimentally,and it is proved that zircon powder has the possibility of filling as a slurry filling material.Through experimental testing and comparative analysis of the physical properties of zircon powder and fly ash materials(including particle size,true density,surface area),epimorphology and chemical composition,it is concluded that the true density and surface area of zircon powder materials are greater than each other in the tested fly ash materials;Based on the key properties of the availability of filling materials-slurry stability,fluidity and compression,the characteristic experiment of slurry is designed.The stability of the slurry is reflected by the rate of precipitation,the fluidity of the slurry is measured according to the strength of the plastic viscosity,and the compression of the slurry is judged by the size of the material compaction coefficient.Experimental study was carried out on the slurry properties of zircon powder material and zircon powder and fly ash mixture material.The results showed that,in the concentration range of 40% to 80% commonly used in slurry,the fineness of zircon powder was controlled at no more than 60% when the margin of the sieve was not greater than 60%,and the sedimentation of zircon powder and mixed material slurry was not greater The rate is lower than that of fly ash,the plastic viscosity is in the plastic viscosity range of fly ash,and from the point of view of stability and fluidity,the zircon powder material and the zircon powder and fly ash mixture material can be used as the filling material.The compaction coefficient of zircon powder material is lower than that of fly ash material,which indicates that more zircon powder material can be consumed under the same slurry conditions,and the side verification cladding isolation slurry filling and mining technology can be developed to carry out the resource-based treatment of coal zircon solid waste.This paper contains 33 figures,25 tables and 119 references. |
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