| 摘要 |
PURPOSE:To obtain feedstock for mullite ceramics in low costs by forming a mixture of deironated and decarbonized coal ash and alumina and firing the products. CONSTITUTION:Alumina is added to deironated and decarbonized coal ash, the mixture is formed and fired to give the subject material. The ash is reduced less than 2wt.% in iron and less than 0.5wt.% in carbon. The deironation treatment is carried out by using a magnetic separator, when needed, followed by treatment with hydrochloric acid or sulfuric acid. The decarbonization is effected in order to reduce carbon residue (including unchanged coal) by calcinating at 800 to 900 deg.C after deironation. Unsatisfactory pretreatment forms foams during the firing of the formed products. The residual iron causes colored (red brown) products with market value reduced. |
