Abstract: In this paper， a series of polypropylene （PP）-based composites were prepared through melt blending using titanium removal tailings as an inorganic filler and KH-570 （γ-methylacryloxy propyl trimethoxysilane） as a coupling agent. The properties of the composites were characterized by using universal testing machine， scanning electron microscope， and differential scanning calorimeter （DSC）， and the influencing factors were analyzed. The results indicated that the tensile strength of the composites was inversely proportional to the addition amount of titanium tailings. The tensile strength of the composites was effectively improved by washing titanium tailings. The modified slag has better dispersibility in the matrix， the composite samples prepared by using the modified slag exhibited higher tensile strength than the unmodified sample. Meanwhile， their lipophilicity was enhanced， but their hydrophilicity was deteriorated. After screening and grading， the titanium tailings exhibited a more uniform particle-size distribution， and the composites presented higher tensile strength than the unscreened system at titanium tailing loadings of 10 and 30 wt%.

Key words: titanium tailings removal, modification, washing, particle size, mechanical property