Industrial Tests Of Sludge Atomizing And Drying In Cement Kiln System

With the development of the society and the large-scale construction of the city, the production of sludge is becoming larger and larger, which has caused serious environmental problems. The high temperature in cement kiln system provides a perfect for sludge burning. It has many social meanings to develop the technology of sludge burning in cement kiln system. We finished the construction of the industrial demonstrate line of “the technology of sludge atomizing, drying and burning in cement kiln system”. Industrial tests carried on this line have provided important theory support and reference data development of this technology.After debugging the line, the properties of sludge in the pump were tested. The results showed that recirculating pumping improved the flowability of sludge. The pressure in the pipeline would have a sudden increase when the open angle of ball valve was 15°. If the quantity of sludge was less than 2t/h, the thermal system and the fly ash could keep stable.In drying or burning process the volatilization and stabilization of heavy metals was studied by ICP. It was found that the volatilization of heavy metals would increase with temperature increasing. CaO could restrain the volatilization and the more the better. Cement could stabilize most heavy metals and 85.5% Cd, 95% Cu, 83% Ni were stabilized in cement.In drying process the volatile gases from sludge were studied by GC-MS. The kinds of harmful nitrogenous orbenzene-containing gases would increase if the temperature became higher. The fly ash could restrain or adsorb the harmful nitrogenous or benzene-containing gases. The sulfurous gases could not be restrained or adsorbed by fly ash, and all the sulfurous gases were disulphide.Five heat balance equations were built to analyze the i MPacts of sludge fed into the cement system. The results showed the critical value of water content and calorific value. The further the water content and calorific value was away from their critical values, the greater influence would get on the thermal process. It would save more coal if the water content got lower or the calorific value became higher.All the results have provided important theory support and reference data for “the technology of sludge atomizing, drying and burning in cement kiln system”.