Significantly Enhanced Density and Mechanical Strength of Carbon/Graphite Blocks by Waste Gas Pressurized Sintering

Abstract

Carbonization under pressure is crucial for enhancing carbon/graphite materials. However, conventional pressure sintering, relying on mechanical or external gas pressure, often results in incomplete densification and structural defects due to uncontrolled volatile gas release. Herein, high‐density and high‐strength self‐sintered carbon block in enclosed‐space (SCB‐E) are produced using waste gas pressurization (WGP) derived from green petroleum coke (GPC). This method can enhance the formation of C─O─C and C═O bonds by promoting dehydration polymerization reaction, which induces interfacial bonding in the carbonization process. Consequently, a decreased mass loss, increased volume shrinkage, and reduced porosity are observed, thereby endowing the obtained SCB‐E with significantly improved density and mechanical strength. Specifically, the compressive and flexural strengths of SCB‐E are 6.36 and 5.77 times higher than SCB‐O sintered in open‐space, respectively, while the corresponding graphite block (SG‐E) achieves 7.74 and 4.58 times greater compressive and flexural strengths than SG‐O. Notably, WGP not only enhances the yield of crack‐free carbon blocks and supports scale‐up production but also integrates seamlessly with traditional kneading processes to produce high‐density, high‐strength carbon blocks (CB‐E). The current approach offers an innovative and important platform for enhancing the density and mechanical properties of bulk materials.