炼铜尾渣−湖泊底泥复合陶粒制备及其性能

Preparation and properties of copper slag tailing−lake sediment ceramsite

以炼铜尾渣和湖泊底泥协同资源化利用为目的,采用炼铜炉渣的再选尾矿和周边湖泊的底泥为原料,通过化学分析、ICP、XRD、SEM和热分析等手段,分析原料的物理化学性质和燃烧特性,考察炼铜尾渣-湖泊底泥制备陶粒过程中的工艺特性和产品性能。首先,探讨预热温度、预热时间、焙烧温度、焙烧时间和原料配比等条件对炼铜尾渣-湖泊底泥复合陶粒性能的影响;其次,采用毒性浸出方法,测定常见重金属的浸出毒性,评估复合陶粒重金属的固化效果;最后,分析化学成分变化和微观形貌特征,探讨复合陶粒的膨胀机理。研究结果表明:炼铜尾渣的掺入对湖泊底泥复合陶粒的制备及性能均具有重要的影响,当炼铜尾渣与湖泊底泥质量比为10:100,500℃下预热15 min,1 140℃下焙烧12 min,制得表面光滑、内部孔隙发育、膨胀良好的复合陶粒制品,其表观密度为936 kg/m3、抗压强度为1.74 MPa、1 h吸水率为14.9%。当焙烧温度为1 140℃时,复合陶粒中重金属固化效果较好,其中Cu,Pb,Zn,Ni和Cr等常见重金属的浸出毒性都小于国家限定标准,炼铜尾渣-湖泊底泥陶粒制品具有自身质量轻、孔隙率高、重金属固化率高的特点。

For the purpose of the reclamation of copper slag and lake sediment,flotation tailings of copper slag and lake sediment from the around lake were used as raw materials to prepare ceramsite.The physicochemical properties and combustion characteristics of raw materials were analyzed by chemical analysis,ICP,XRD,SEM and thermal analysis.Moreover,the technological characteristics and product properties in the preparation of ceramsite from copper slag tailing and lake sediment were investigated.Firstly,the effects of preheating temperature,preheating time,roasting temperature,roasting time and raw material ratio on the properties of composite ceramsite from copper slag tailing and lake sediment were discussed.Secondly,the leaching toxicity of common heavy metals was measured by toxic leaching method and the solidification effects of heavy metals in composite ceramsite were evaluated.Finally,the expansion mechanism of composite ceramsite was discussed by analyzing the changes of chemical composition and micro morphology.The results show that the additions of copper slag tailing has an important effect on the preparation and properties of lake sediment composite ceramsite.When the mass ratio of copper slag tailing to lake sediment is 10꞉100,the composite ceramsite products with smooth surface,developed internal pores and good expansion are prepared by preheating at 500℃for 15 min and roasting at 1140℃for 12 min.The apparent density of composite ceramsite from copper slag tailing and lake sediment is 936 kg/m3,the compressive strength is 1.74 MPa and the water absorption in 1 h is 14.9%.When the roasting temperature is 1140℃,the heavy metal solidification of ceramsite is relatively good and the leaching toxicity of common heavy metals such as Cu,Pb,Zn,Ni and Cr is lower than the national limits.Copper slag tailing-lake sediment ceramsite has characteristic with light mass,high porosity and good heavy metal solidification.