铝厂污泥在不同煅烧温度的晶相结构研究

铝厂污泥主要成分是-AlOOH,其中部分是晶体,部分是无定形体。将此污泥分别于450,600,800,1000,1050,1200和1300 ℃进行了煅烧,探讨污泥在不同温度下的晶相变化,为污泥的综合利用提供可靠的数据。采用XRD法和SEM法表征了污泥在不同温度下的晶相结构和显微结构。实验结果表明:随着煅烧温度的提高,污泥发生如下变化过程: 这与常规转化规律不同。在450,600,800,1000和1100 ℃的试样中均形成了-Al2O3和无定形体结构的微晶,随着温度的升高,-Al2O3含量增加而无定形体结构的微晶含量降低。当煅烧温度上升至1200和1300 ℃时, - Al2O3和无定形体结构的微晶全部转变为 - Al2O3。 -Al2O3是介稳态,高活性,-Al2O3是稳定态,低能态。

Polycrystalline Structure of Waste Slag in Aluminum Factory at Different Calcining Temperature

The waste slag of aluminum factory composed of crystalline -AlOOH and amorphous solid was calcined at 450, 600, 800, 1000, 1100, 1200 and 1300 ℃, respectively, and the changes of crystalline phase at different temperature can provide us suitable data for its comprehensive applications. Their polycrystalline structures and microstructures were characterized by XRD and SEM techniques. The crystalline phases of the waste slag were changed as the increasing of calcining temperature: It is different from our process. Both -Al2O3 and amorphous solid were formed in the samples at 600, 800 and 1000 ℃. The contents of -Al2O3 and amorphous solid decrease with the rise of calcining tempe- rature, and they are completely transformed into -Al2O3 when the temperature increased up to 1200 ℃. -Al2O3 was metastable phase with high-activity while -Al2O3 was stable phase with low-activity.