Abstract:

Traditional carbon emission calculation methods typically employ industry or national average emission factors， which cannot accurately reflect the regulatory mechanism of cement’s mineral formation characteristics on carbon emissions during the reaction process. These methods focus on inventory analysis and aggregation of energy consumption and emissions in processes such as raw material grinding， clinker calcination， and cement grinding， but fail to address the fundamental issue of where energy is consumed at the molecular level. However， the final performance and environmental impact of cement are fundamentally determined by its mineral composition.

Based on the concept of material genome， generally understood as the basic structural unit that maintains the intrinsic characteristics of materials， this paper proposed a material genome-based carbon emission accounting method utilizing the four main minerals of cement. By incorporating the regulatory mechanism of thermodynamic characteristics of materials during the reaction process on carbon emissions， a material genome-based carbon emission accounting model was constructed. This model linked microscopic mineral thermodynamic data with macroscopic industrial production parameters to reveal the impact pathways of different steel slag utilization methods in cement production on carbon emissions， and compared them with traditional calculation methods.

The results show that carbon emission values calculated by the material genome accounting method fluctuate within 2.86% to 4.07% compared to those calculated by traditional methods， indicating close agreement. Meanwhile， compared to traditional methods， it better reflects the impact of changes in mineral composition ratios on carbon emission values and more accurately calculates carbon emissions for various types of solid waste cement. This facilitates direct accounting of product carbon emissions through terminal product composition and guides formula design. In different application cases such as using steel slag as alternative raw material for cement production， cement admixture， and carbonated cementitious material， cement prepared using carbonated steel slag powder exhibits the lowest carbon emission intensity ratio. After excluding the impact of transportation， the carbon emission intensity ratio is 16.04 kgCO₂/MPa. Meanwhile， without considering variable factors such as transport distance， its overall carbon emission is also relatively the lowest， with only 726.62 kgCO₂ emitted per ton of cement. For steel slag used as alternative raw material and steel slag phase-separated clinker technology， the carbon emission values of the two are similar， but the carbon emission of steel slag phase-separated clinker technology in the process and fuel stages is 3.47 kgCO₂/t lower than that of steel slag as alternative raw material. Additionally， if road transportation is adopted， when the transport distance exceeds 140 km for steel slag as alternative raw material， the carbon reduction effect of steel slag approaches zero； for cement prepared with steel slag treated by high-temperature reconstruction， cement admixture， carbonated cementitious material， and phase-separated clinker technology， these distances are 233， 240， 263， and 109 km， respectively. Therefore， the transportation distance radius for steel slag utilization should not exceed 300 km. The material genome method can reflect the regulatory mechanism of thermodynamic characteristics of materials on carbon emissions during the reaction process， providing data basis for cement enterprises to screen and optimize steel slag utilization schemes.

Key words: material gene, steel slag, cement, cement mineral, carbon accounting, carbon emission intensity ratio