制备工艺对污泥陶粒表面裂缝和孔隙率的影响

Effect of preparation methods on surface crack and the porosity of building ceramsite with domestic sludge

为了优化污泥制备陶粒的工艺,从不同成球工艺、干燥方式、热处理制度、煅烧温度等方面分析了陶粒表面裂缝和孔隙率的变化,并评价所制备陶粒的性能。结果表明,采用自然晾干2 h后干燥,接着在400℃预热10 min后在1100℃煅烧30 min是较好的制备工艺,可有效消除陶粒表面裂缝,提高了孔隙率,且陶粒的1 h吸水率、抗压强度、软化系数、粒型系数等均符合GB/T 17431.1—2010的要求,重金属溶出率符合GB 25467—2010的要求。

In order to optimize the preparation of sludge ceramsite,thevariation of the pelletizing, drying,preheat-treating and burning processes on the surface cracks and porosity of the ceramsite was analyzed and the property of ceramsite was also evaluated. The results show that the surface cracks of the ceramsite are effectively eliminated and the porosity is increased after raw meal ball is dried in oven after 2 h natural dry,then preheated for 10 rain at 400℃ and sintered for 30 min at 1100 ℃. The amount of 1-hour water absorption,compressive strength, softening coefficient,grain shape coefficient meet the requirement of GB/T 17431.1-2010,and dissolution rate of heavy metals of sludge ceramsite is also superior to Chinese standard requirements of GB 25467-2010.