<p>Based on industrial waste recycling, calcium silicate hydrate (CSH) powder was hydrothermally synthesized using carbide slag and silica fume from processes of hydrated acetylene and ferrosilicon alloy smelting with the mass ratio of 1:1. To address practical limitations of CSH powder as an adsorbent (e.g., particle loss, partial blocking and difficult separation), sodium alginate (SA) was introduced to fabricate SA/CSH composite gel beads and realize CSH immobilization. It was concluded that such gel entrapment did not impair Cu²⁺ and Ni²⁺ removal performance of CSH powder. When the mass ratio of CSH to SA was 0.5, Cu²⁺ and Ni²⁺ maximum adsorption capacities were up to 208.5 mg/g and 147.0 mg/g, respectively, with an initial concentration of 300 mg/L at 313 K under pH 6, in line with the fitting of the Langmuir isothermal model. And the kinetics were well fitted by the Ho quasi-second-order model. The coexisting Na⁺, Mg²⁺, and Ca²⁺ gradually weakened Cu²⁺ and Ni²⁺ adsorption with the increase in ion concentration. A large amount of Ca²⁺ active sites in SA/CSH gel promoted the chemisorption of Cu²⁺ and Ni²⁺ through ion exchange. In addition, functional groups such as COO-, -O-, and -OH in gel beads fully exerted synergistic complexation. A combined mode for SA/CSH regeneration using 0.02 mol/L EDTA-2Na elution coupled with 5 wt % CaCl₂ for Ca²⁺ replenishment achieved more than 85% of recovery rate after three cycles. Such SA/CSH gel thus presents a promising alternative for heavy metal removal from wastewater.</p><p></p>