Recycling Of Spodumene Slag And Preparation Of Composite Materials

Spodumene slag is a kind of industrial solid waste that was produced by spodumene ore extraction of lithium carbonate(mainly used light volt industry).Along with serious environmental pollution increasingly,the second utilization of industrial and living solid waste becomes more and more important.Lithium ore is mainly distributed in Australia,China,the United States,Canada and Brazil.For these countries,these problems of spodumene slag included place occupies,management needs,erosion easily with wind and rain,farmland pollution.So,how to deal with spodumene slag has become an urgent problem.At the moment,the main processing approaches of spodumene slag were preparation of spodumene slag concrete or ceramics.But these approaches for the recycling of spodumene slag scale is limited,The approaches are unable to solve these problems furthest and low value-added business.Therefore,spodumene slag and polymer composites could be very efficient to solve these problems.Polylactic acid(PLA)/spodumene slag and thermoplastic polyester elastomer(TPEE)/spodumene slag composite material were prepared by melt blending.Then,spodumene slag was dealt with different chemical modification,filled polymers to improve the mechanical properties of composites.The structure and properties of composites were studied in details by the morphology characterization,dynamic mechanical analysis,rheology and so on.The relationship between structure and properties of composites were described by crystallization kinetics theory,viscoelastic theory and mechanical models。(1)Spodumene slag was treated by alkali.Silicon was extracted and made of amorphous silica nanoparticles.Spodumene slag/PLA composite materials were prepared by melt blending and compared the morphology and properties with unmodified micron-grade.spodumene slag filling PLA composite m aterial.The results reveal that unmodified spodumene slag could increase the PLA’s young’s modulus without reducing tensile strength.It has a good role of inert filler.Nanoscale spodumene slag could not only increase the PLA’s young’s modulus,but also greatly improve the tensile strength.It has a good role of active strengthening agent.(2)Different components of spodumene slag/TPEE composite was prepared by melt blending.PEG-modification of spodumene slag was modified by polyethylene glycol(PEG).Atomic force microscope(AFM),Differential scanning calorimeter(DSC)and Universal electronic tensile machine results reveal that hard segment of pure TPEE distributes in the soft segment of pure TPEE by nano-scale grain size.The heterogeneous nucleation of TPEE was increased with filling spodumene slag and PEG-modification of spodumene slag.Young’s modulus and yield strength were increased.Hard segment and PEG-modification of spodumene slag combined well with "Ball effect" lower in composite materials.Under the same filling quantity Young’s modulus and yield strength of composites was higher and enhancement effect better.(3)Spodumene slag/graphene composite was prepared by chemical modification of Graphene oxide and spodumene slag.X-ray photoelectron spectroscopy(XPS)results reveal the chemical bond of spodumene slag/graphene composite.Atomic force microscope(AFM)results reveal the microstructure of spodumene slag/graphene composites.The results Showed that graphene and spodumene slag produce chemical bond and graphene closely"posted" spodumene slag surface.Spodumene slag/graphene/TPEE composite was prepared by melt blending.Rotational rheometer and Universal electronic tension machine results reveal that the elastic and viscous of spodumene slag/graphene/TPEE composites had obvious enhancement and formed percolation network structure.It’s mechanical properties were enhanced greatly.Young’s modulus and yield strength of composite was higher than unmodified spodumene slag/TPEE composite.