Study on magnesium slag desulfurizer modified by additives in quenching hydration

The desulfurization performance of magnesium slag has been improved by the modified method of quenching hydration, but it still cannot meet the industrial requirements. Based on the research of additives for calcium-based desulfurizer, NaCl, CaCl₂, Na₂SO₄, CaSO₄, Na₂CO₃, K₂CO₃, acetic acid and adipic acid are used for modification of quenching hydrated magnesium slag. TGA are used for analysis of magnesium slag desulfurization performance; XRD, SEM, EDS and BET are used for analysis of modified magnesium slag composition, surface morphology and microscopic characteristics, respectively, obtaining the modification mechanism of different additives on the quenching hydrated magnesium slag. The results showed that: the best desulfurizer was 2% Na₂SO₄ modified magnesium slag, and the calcium conversion rate reached 40.16%. Cl⁻ and SO₄²⁻ mainly improve the desulfurization performance of magnesium slag by improving the specific surface area and pore volume of magnesium slag, and the modification effect of SO₄²⁻ was better than Cl⁻. CO₃²⁻ mainly through the reaction with Ca(OH)₂ to produce CaCO₃ that could crystalize on the surface of magnesium slag, thus improving the desulfurization performance of magnesium slag. Organic acids enhanced the transmission of H⁺ in hydrated slurry and promoted the dissolution of Ca₂SiO₄.