铵浸钢渣熔融还原提铁制备微晶玻璃研究

利用氯化铵浸出钢渣,可有效浸取Ca元素并就地固定CO₂制备碳酸钙,浸出后的铵浸渣由于CaO含量的降低,无需加入大量的改质剂就能还原提铁并制备微晶玻璃。基于此,引入热力学计算,对铵浸钢渣提铁并制备微晶玻璃的可行性进行探究,初步结果表明铵浸钢渣与40wt%的SiO₂混合后进行提铁,铁的还原率高达98.47%,且还原渣物相主要为透辉石;由还原渣制备得到的基础玻璃在800℃下核化1 h,960℃下晶化1 h,得到微晶玻璃,其主晶相为透辉石,并夹杂部分钙长石;基础玻璃析晶活化能为597.4 kJ/mol,晶体生长指数均小于3,为表面析晶。

Study on Glass-ceramics Preparation through Melting Reduction of Steel Slag Leached by Ammonium Chloride

Calcium element can effectively be leached out and carbon dioxide can be sequestered on the spot to prepare commercial calcium carbonate through leaching of steel slag by ammonium chloride.Due to the decrease of CaO content in steel slag leached by ammonium,there is no need to use a lot of modification agent to reduce and extract iron and prepare glass-ceramics.Therefore,thermodynamic calculation was introduced to explore the feasibility of extracting iron from ammonium leaching steel slag and preparing glass-ceramics.The preliminary results shows that for the mixture of steel slag leached by ammonium chloride and 40wt%SiO2,the reduction rate of iron is as high as 98.47%,and the main phases of reducing residues is diopside;the main crystal phase of glass ceramics is diopside mixed up with some calcium feldspar by nucleation for 1 h at 800℃and crystallization for 1 h at 960℃;and the crystallization activation energy of base glass is 597.4 kJ/mol,and the crystal growth indexes are all less than three,indicating surface crystallization.