## 5 Conclusions  
In this study, PG was synergistically cured by RM and OPC to form a class of RCPB with excellent mechanical properties and environmental safety, and the slurry concentration was optimized to balance the mechanical properties, fluorine fixation efficacy, and environmental safety of the materials. The experiments showed the following:  
(1) This study establishes that slurry concentration critically influences material performance, with optimal outcomes observed at elevated concentrations. The synergistic interaction between RM and PG underpins this enhancement, as RM's alkaline components neutralize PG's acidity and mitigate fluoride ion migration. This is achieved through accelerated hydration kinetics and the development of a robust microstructure anchored by C-S-H gel and AFt formation. (2) Microstructural analysis reveals that higher slurry concentrations promote densification and reduced porosity, directly correlating with improved mechanical properties. However, excessive AFt generation introduces microstructural stresses, which may temper long-term strength progression. These findings underscore the importance of balancing hydration kinetics and crystalline phase formation in material design. (3) The immobilization of fluoride ions is governed by a dual mechanism: physical encapsulation within the stabilized matrix and chemical interactions via precipitation and ion exchange processes. This combined approach ensures effective containment of fluoride, aligning with sustainable strategies for managing industrial by-products. Chemical precipitation: Free Ca\({}^{2+}\) reacts with F\({}^{-}\) to produce insoluble CaF\({}_{2}\) precipitate, which reduces fluoride ion mobility. Physically encapsulated hydration products (C-S-H gel and AFt) immobilize fluoride ions through surface hydroxyl adsorption and pore encapsulation. In addition, the alkaline component (Na\({}_{2}\)O) of RM not only effectively neutralizes the acidic environment of PG but also promotes the formation of sodium Na\({}_{3}\)AlF\({}_{6}\) precipitation, and Na\({}^{+}\) reacts with Al\({}^{3+}\) and F\({}^{-}\) in PG to produce sodium Na\({}_{3}\)AlF\({}_{6}\) precipitation, and its high specific surface area (152 m\({}^{2}\)/g) strengthens the long-term stability of fluorine through physical adsorption, which significantly improves fluorine's long-term stability. This study not only provides theoretical support for the efficient resource utilization of PG but also provides innovative ideas for the co-disposal of industrial solid waste and the development of environmentally friendly building materials. Future research needs to further verify the long-term durability of the material and its adaptability in complex environments (e.g., freeze-thaw cycles, acidic precipitation, etc.) in order to promote its practical engineering applications. By optimizing the proportion and process parameters, this technology is expected to be popularized on a large scale in the fields of mine filling and foundation reinforcement, which will help realize the goals of circular economy and sustainable development. Conceptualization, J.Y. and B.L. ; Methodology, J.Y. and B.L. ; Formal analysis, Y.F. ; Investigation, J.Y. and B.L. ; Resources, Q.Z., D.W. and Q.C. ; Writing--original draft, J.Y. and B.L. ; Writing--review & editing, B.L., D.W., Q.C. and Y.F. ; Visualization, J.Y. ; Supervision, Y.F. ; Project administration, Q.Z., D.W. and Q.C. ; Funding acquisition, Q.Z. All authors have read and agreed to the published version of the manuscript. **Funding:** This research was funded by [the National Natural Science Foundation of China] grant number [No. 52274151 and 52474165] And The APC was funded by [the National Natural Science Foundation of China]. Information regarding the funder and the funding number should be provided. **Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable. **Data Availability Statement:** Where data is unavailable due to privacy or ethical restrictions.