In response to the problem of difficult recycling and utilization of bulk industrial solid waste, various goals of solid waste reduction, harmless treatment, and resource utilization were achieved. By utilizing the harmless treatment slag of electrolytic manganese residue, red mud, and coal fly ash from three typical types of bulk solid waste from enterprises in southwestern China: gypsum, alkaline, and silicoalumina, an environmental protection permeable concrete paving bricks (PCB) were prepared. The effect of water washing and slag content on the mechanical properties and leaching toxicity of the prepared PCB was studied, and the phase composition and microstructure of the optimal performance PCB were analyzed by X-ray diffraction (XRD) and Scanning electron microscopy (SEM). The results show that: (1) with the increase of the amount of harmless slag and water washed harmless slag added, the splitting tensile strength and linear failure load of road bricks undergo significant changes, and the overall trend is decreasing. When the amount of harmless slag added is 6%, water washed harmless slag added is 14%, after 28 days of curing, the splitting tensile strength of the prepared bricks is 4.09 MPa and 3.46 MPa, respectively, reaching the splitting tensile strength levels of fts
4.0 and fts
3.0 specified in Permeable Paving Bricks ＆ Permeable Paving Flags
(GB/T 25993-2010). (2) The leaching toxicity of heavy metals and NH4+
-N in road bricks is lower than the relevant requirements in the Technical Specification for Coprocessing of Solid Waste in Cement Kiln
(GB 30760—2014). The main phases of pavement bricks are calcite, quartz, and ettringite, which are the main supporting substances for strength development. Research has shown that the harmless slag obtained from the collaborative treatment of electrolytic manganese residue, red mud, and coal fly ash can replace some raw materials to prepare permeable concrete paving bricks, meeting the relevant standards of mechanical properties and leaching toxicity, and effectively promoting the reduction and resource utilization of solid waste. It is recommended to further conduct environmental risk tests on bricks in practical application scenarios, to provide clearer support for the comprehensive utilization technology development of electrolytic manganese slag, red mud, and coal fly ash.