<p>As a critical pillar of China’s dual-carbon strategy, decarbonizing the steel industry requires innovative alternatives to conventional carbon-intensive iron ore agglomeration methods. A key challenge in enhancing the mechanical strength of cold-bonded pellets (CBPs), a sustainable low-temperature agglomeration technology, was addressed through binder optimization and structural reinforcement. Forming and consolidation regimes of CBPs were systematically optimized. Optimal parameters were identified as 7% moisture content, 60&#xa0;MPa compaction pressure, and drying at 100&#xa0;°C for 3 h, resulting in superior pellet quality and mechanical performance. By systematically investigating the effect of sodium silicate binders with varying moduli on CBPs performance, the adsorption behavior on iron ore surfaces and the underlying consolidation mechanism were elucidated. Advanced characterizations using X-ray photoelectron spectroscopy and in situ attenuated total reflectance Fourier-transform infrared spectroscopy revealed an adsorption–polycondensation mechanism: Silicate species initially bind to the iron ore surface via Fe–O–Si linkages and subsequently polymerize into a three-dimensional Si–O–Si network during curing. To overcome the inherent strength limitations of the silicate network, 0.2 wt.% nano-SiO₂ was introduced as a reactive Q⁰ units dopant, accelerating gelation and network densification. This modification enhanced the compressive strength of the pellets to 2376.3 N pellet⁻¹, meeting the stringent mechanical requirements of blast furnace feedstock. These findings advance fundamental understanding of agglomeration mechanisms in cold-bonding systems and establish a scalable strategy for high-performance binder selection and structural reinforcement in low-carbon burden development.</p>