AbstractAn efficient and recyclable cadmium removal adsorbent was prepared by molding and sintering of ultrafine silica powder produced from ferroalloy plant as the main raw materials, with the addition of a certain amount of Al(OH)3 and CaO for modification. XRD and SEM were used to characterize the crystal phases and microstructures of the adsorbent. The influences of different pH, initial cadmium concentration and contacting time on the cadmium adsorption capacity were investigated. The results show that the cadmium removal capacity is up to 0.239 mg/g at the initial Cd2+ concentration of 5 g/L, pH value of 7 and contacting time of 120 min when the optimum mass ratio is 70(ultrafine silica powder):30(Al(OH)3 and CaO mixture). The corresponding adsorbent has a porous structure with main crystalline phases of Ca2Al2SiO7 and CaSiO3. Cadmium is adsorbed and removed mainly by physical adsorption, assisted by chemical adsorption.