Back to results
US 9,539,581 B2Granted
Method for recycling ash
AssigneeMaterials Recovery Corporation
InventorsJohn W. Pickens, James H. Riccardi
Life of this patent
Estimating the term…
Abstract
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.
Claims42
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%.
3 more elements
A method for recovering metals from combustion ash comprising:
- a. providing a feedstock source of ash;
- b. subjecting the ash to a primary comminution step and a separate secondary comminution step, said steps performed in series to produce comminuted ash and reduce the particle size of substantially all nonmetal particles contained within said comminuted ash to less than about 2 mm and substantially liberate metal particles entrapped therein, the metal particles comprising relatively ferrous particles and relatively nonferrous particles;
- c. performing a classification step, wherein the comminuted ash is classified into three or more streams of varying particle size cuts using a mechanical screening system, wherein at least one stream comprises a particle size cut equivalent to a minimum of about −10 mesh;
- d. applying a multi-phase magnetic separation system to at least one of the streams of varying particle size cuts, wherein said magnetic separation system is operated with a progression of higher magnetic field strengths to progressively remove a series of magnetic particles with decreasing ferrous content thereby producing at least one ferrous metal product;
- and
- e. performing at least one separation method based on particle size differentiation to produce at least one metal product with a nonferrous metal content greater than about 70%.
3 more elements
Dependencies are inferred from the claim text.