二次铝灰制备高强度陶粒及其性能研究

作为再回收铝过程中产生的废渣,二次铝灰具有明显的化学反应性和有毒、有害物质浸出等危险性特征。为了解决制铝行业中产生的二次铝灰堆存处置问题,以二次铝灰为原料,通过水洗、圆盘造粒,再经1 200～1 400℃热处理,制备了高强度陶粒。运用X射线衍射仪和扫描电子显微镜对不同热处理温度下陶粒试样的物相组成和微观形貌进行分析,并对材料堆积密度、表观密度、孔隙率以及筒压强度进行了测试。结果表明：随着热处理温度升高,陶粒内部结构逐渐致密化,堆积密度、表观密度及筒压强度均随之增大;其中,1 400℃热处理后,陶粒的主要物相为刚玉和镁铝尖晶石,其表观密度和体积密度分别为1.82 g/cm³和1.81 g/cm³,筒压强度可达25.7 MPa,属于高强度陶粒。

Preparation and Properties of High Strength Ceramsite from Secondary Aluminum Ash

As the waste residue generated in the process of aluminum recycling, the secondary aluminum ash has obvious chemical reactivity, leaching toxicity of toxic and harmful substances and other dangerous characteristics. In order to solve the problem of stockpiling and disposal of secondary aluminum ash generated in aluminum industry, the secondary aluminum ash was used as raw material to prepare high strength ceramsite through water washing, disk granulation and 1 200~1 400 ℃ heat treatment. The phase composition and micromorphologies of the ceramsite samples sintered at different temperatures were analyzed by X-ray diffractometer and scanning electron microscopy. The bulk density, apparent density, porosity and cylinder compressive strength of the ceramsite were tested. The results show that with the increase of heat treatment temperature, the internal structure of ceramsite becomes denser gradually, and the bulk density, apparent density and cylinder compressive strength increase. The main phases of ceramsite after heat treatment at 1 400 ℃ arecorundum and magnesia alumina spinel. The apparent density, volume density and cylinder compressive strength of ceramsite are 1.82 g/cm³, 1.81 g/cm³ and 25.7 MPa, respectively, meeting the requirements of high strength ceramsite.