It is a very difficult problem to deal with the damaged dust filter bag. Because there is a lot of dust on the surface of the waste filter bag, the dust composition is complex. For example, the filter bag used in the waste incineration industry contains toxic, harmful and corrosive substances such as heavy metals and Er on the surface. .Chemical treatment method can also use high temperature cracking method.

pyrolysis method

Pyrolysis is to use higher temperature to decompose PTFE. This method is difficult to control the types of decomposition products, and also produces many toxic by-products. In the process of recovering useful decomposition products, the requirements for process equipment and parameter settings are relatively high, and the application of this method is generally discouraged.

The pyrolysis method has lower requirements for the PTFE recycled material. Whether it is pure PTFE or filled with other materials, it can be recycled by the pyrolysis method. The factors that affect the pyrolysis are generally: temperature, pressure, time, atmosphere, feeding speed, etc.

There is no relevant report on pyrolysis recovery in China, and there is no specific process operation. The main reason is that the process is too complicated and the investment is too large. There are many researches in this area abroad, and some of the results have been put into industrial production: CMSimon et al. Fluidized bed pyrolysis is used to decompose PTFE waste to recover TFE, HFP and OFCB. When the process parameters are the fluidized bed temperature of 600°C and the reaction residence time of 3s, the mass fraction of the recovered material is as high as 91%, and the filler in the waste can also be recovered, such as glass fiber, graphite, copper powder, etc.) This system has the largest The characteristic is that it can be operated continuously. The system has been industrialized in Germany, and the processing capacity of waste PTFE is 400t/year.