Effects of additive content on structure and properties of siderite tailings-based stone paper

This study utilized siderite tailings and polypropylene as the main raw materials to prepare stone paper composites through the melt blending and hot-pressing molding process. Using characterization techniques such as scanning electron microscopy and a universal electronic testing machine, the effects of the addition amounts of four different additives – calcium stearate, maleic anhydride grafted polypropylene, silane coupling agent KH550, and polypropylene toughening agent – on the microstructure, tightness, tensile strength, smoothness, and tear resistance of the materials were systematically investigated under a fixed tailings content of 40%. The results demonstrated that an appropriate number of additives effectively improved the overall performance of the materials, whereas excessive addition not only increased costs but also potentially led to a decline in performance. In summary, the rational use of additives significantly enhanced the compatibility and dispersion between the tailings and the polypropylene matrix. Under the specific conditions of 40 wt% siderite tailings loading and the processing parameters used in this study, the optimal addition amounts for calcium stearate, maleic anhydride grafted polypropylene, KH550, and the polypropylene toughening agent were found to be 2, 2, 2, and 5%, respectively.