This should be discussed on a case by case basis and cannot be generalized. The fly ash after incineration of some heavy metal hazardous wastes is still hazardous waste, which will cause secondary pollution to the environment, such as copper containing hazardous wastes, which can not be incinerated; However, some hazardous wastes containing heavy metals are not dangerous after incineration. Such hazardous wastes containing heavy metals can be incinerated. Therefore, the specific thing is to consult the environmental protection consultant or let the environmental protection consultant go to the site to understand the situation.