碳热还原电厂粉煤灰冶炼硅铝铁合金

Production of Si-Al alloy with carbothermal reduction of fly ash from thermal power plant

电厂粉煤灰中主要含有SiO2和Al2O3,且含有一定量的残炭。采用粉煤灰和铝土矿等为主要原料进行了高温下制备硅铝铁合金研究,结果表明,利用电厂粉煤灰和铝土矿为主要原料,配加赤铁矿、硅石和添加剂CaF2,在1 880℃时经碳热还原可以制备硅铝铁合金,提高粉煤灰的利用价值,减少其环境污染。在1 750℃时,还原反应进行不完全,得不到硅铝铁合金。在1 880℃时还原出的合金主要成分为Si,Al和Fe,其平均含量分别为27.69%,8.75%和58.81%,合金的主要物相为Al0.3Fe3Si0.7,SiC,FeSi和FeC。

Fly ash mainly contains SiO2 and Al2O3 as well as certain amounts of residual carbon. In this study, smelting of Si-AI alloy with fly ash and bauxite as the major raw materials at high temperatures was studied. The results showed that Si-Al alloy could be prepared in carbothermal reduction with raw materials of fly ash, bauxite, hematite, silica and additive of CaF2 at 1880 ℃. It could raise the utilization value of fly ash and reduce the environmental pollution. At 1 750 ℃, the reduction reaction was not complete, and Si-Al alloy was not generated. The main compositions at 1 880 ℃ of the reduced alloy were Si, AI and Fe, the average content was 27.69%, 8.75% and 58.81% respectively. The phases of alloy mainly were Al0.3Fe3Si0.7, SiC, FeSi, and FeC.