Method for recycling ash

摘要

Methods and system for recovering metals from combustion ash containing ferrous and nonferrous metals, including the steps of providing a feedstock source of ash, comminuting the ash to substantially reduce the particle size and liberate metal particles therein, separating the metal particles from the comminuted ash by particle size to obtain ash with a reduced metal content, at least one ferrous product and at least one nonferrous product.

主权项

1. A method for recovering metals from combustion ash, comprising the following steps in series:
a. providing a feedstock source of ash; b. performing a comminution step by introducing said ash to high impact and low shear conditions to substantially liberate metal particles entrapped therein and produce comminuted ash, wherein the comminuted ash comprises nonmetal particles with a particle size less than about 2 mm, and said metal particles comprise relatively ferrous particles and relatively nonferrous particles; c. processing the comminuted ash with at least one dry separation method based on particle size to produce a minimum of three streams of varying particle sizes, wherein at least one of the three streams is a refined ash stream with a reduced metal content and at least one of the three streams is a substantially metal particle stream; d. separating a portion of the relatively ferrous particles from the at least one substantially metal particle stream by applying at least one magnetic field to selectively remove magnetic particles and produce at least one ferrous metal product; and e. separating a portion of the relatively nonferrous particles from at least one of the three streams to produce at least one nonferrous metal product with a nonferrous metal content of greater than 70%.