Experimental study on producing ceramsite with sewage sludge in arc blade rotary kiln
弧叶型旋转窑烧制污泥陶粒实验研究

The sewage sludge, PFA (pulverized fuel ash) and harbor sludge were used as raw materials to carry out the experiments. The orthogonal experimental method was used to arrange experiments on the mixture ratio of green pellets and factors of firing process to find out the best ratio of green pellets and the seemly parameters of firing process. In accordance with the selected ratio and firing process factors, experiments were carried out through the arc blade rotary kiln to produce lightweight aggregates. The characteristics of products such as the 1 h water absorption rate, softening coefficient, loose bulk density, apparent density, grain composition, grain shape factor and the extraction toxicity factors were detected. The aggregates made by the arc blade rotary kiln were used to make standard unit concrete instead of stones. After 3 days, 7 days and 28 days standard curing of the concrete, the specifications of the standard unit concrete such as the compressive strength, bulk density and thermal conduction coefficient was tested. The results showed that the lightweight aggregate can fit the correlative standard, and the light concrete made by lightweight aggregates can also fit the standard about the construction material. It was confirmed that the lightweight aggregates made by the arc blade rotary kiln could be used to produce light concrete as coarse aggregates.