直接还原选矿尾渣制备陶粒的研究

Preparation of Ceramsite Using Tailings Discarded after Direct Reduction-Concentration Process

以直接还原选矿尾渣为主要原料,添加城市污水处理厂剩余污泥制备轻质陶粒,考察了烧制过程中各主要因素(预热温度、预热时间、焙烧温度、焙烧时间和原料配比)对陶粒性能(表观密度、堆积密度、1 h吸水率和颗粒强度)的影响,最终确定了烧制陶粒的最佳工艺条件。结果表明,尾渣与污泥的最佳质量比为尾渣∶污泥=95∶5,烧制陶粒的最佳工艺条件为:预热温度550℃,预热时间30 min,焙烧温度1 110℃,焙烧时间6 min,此时制得的陶粒表观密度为1.365 g/cm3,堆积密度0.672 g/cm3,1 h吸水率3.50%,颗粒强度220 N,筒压强度3.5 MPa。

Tailings discarded after direct reduction-concentration process was used as principal ma- terial , adding sewage sludge, to sinter lightweight ceramsite. The optimized preparation conditions were selected. The impacts of main factors （ preheating temperature, preheating time, sintering temperature, sintering time, and material ratio） on characteristics of ceramsite （apparent density, bulk density, water absorption and crushing strength） were studied. The results show that the optimized mass ratio of tailings to sewage sludge was that railings： sewage sludge = 95： 5. The optimized preparation conditions were as follows ： preheating temperature 550℃, preheating time 30 min, sintering temperature 1 110℃, and the sintering time 6 rain. Under these conditions, the characteristics of ceramsite were obtained as follows： apparent densityl. 365 g/cm3, bulk density0. 672 g/cm3, 1 h water absorption3. 50% , crushing strength 220 N, cylinder compressive strength 3.5 MPa.