WO2017172980A1

WO2017172980A1 - Use of multi-gravity separation to recover metals from iba, asr, and electronic scrap

Info

Publication number: WO2017172980A1
Application number: PCT/US2017/024841
Authority: WO
Inventors: Thomas A. Valerio
Original assignee: Valerio Thomas A
Priority date: 2016-03-29
Filing date: 2017-03-29
Publication date: 2017-10-05

Abstract

A method including providing the material (e.g., the material substantially contains incinerator combined ash, automobile shredder residue, electronic scrap, or a combinations thereof), sizing the material using at a screen to recover a first fraction about 0.001 to about 2mm or less, separating the material at greater than 5SG, using a multi-gravity separator having a drum and a screw at least partially within the drum of the multi-gravity separator. The multi-gravity separator separates the material into a second light fraction and a second heavy fraction. The second heavy fraction is substantially precious metals.

Description

USE OF MULTI-GRAVITY SEPARATION TO RECOVER METALS FROM IBA,

ASR, AND ELECTRONIC SCRAP

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to and the benefit of U.S. Patent Application No. 62/314,888, filed March 29, 2016, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

[0002] This disclosure relates to systems and methods for recovering copper, precious metals, and other metals from recycled materials, IBA, ASR, and electronic scrap. More particularly, this disclosure relates to systems and methods for employing a multi-gravity separator to separate materials in the tail end of a recycling and recovering operation.

BACKGROUND

[0003] Recycling of waste materials is highly desirable from many viewpoints, not the least of which is financial and ecological. Properly sorted recyclable materials can often be sold for significant revenue. Many of the more valuable recyclable materials do not biodegrade within a short period, and so their recycling significantly reduces the strain on local landfills and, ultimately, the environment.

[0004] Typically, waste streams are composed of a variety of types of waste materials. One such waste stream is generated from the recovery and recycling of automobiles or other large machinery and appliances. For example, at the end of its useful life, an automobile is shredded. This shredded material is processed to recover ferrous and non- ferrous metals. The remaining materials, referred to as "automobile shredder residue" (ASR), which may still include ferrous and non-ferrous metals, including copper and other recyclable materials, are typically disposed of in a landfill. Efforts have been made to further recover materials, such as non-ferrous metals (including copper from copper wiring), precious metals and plastics. Similar efforts have been made to recover materials from "whitegood shredder residue" (WSR), which are the waste materials left over after recovering ferrous metals from shredded machinery or large appliances. Other waste streams that have recoverable materials may include electronic components (also known as "e-waste" or "electronic scrap" or "waste electrical and electronic equipment" (WEEE)), building components, retrieved landfill material, or other industrial waste streams. There is a high value of metal in the fines of these materials.

[0005] There is always a need for a cleaner, more efficient process and system for recovering metals and useful materials from a waste stream, including ASR. It is to this need, among others, that this application is directed.

SUMMARY

[0006] One aspect of this disclosure is a method for separating metals from a material including providing the material (e.g., the material substantially contains incinerator- combined bottom ash, automobile shredder residue, electronic scrap, or combinations thereof); sizing the material using a screen to recover a first traction of about 1 micron to about 2mm or less, separating the material at about 5.0 SG or greater using a separator into a first heavy fraction and a first light fraction; and feeding the first light fraction into a multi -gravity separator having a drum and a screw at least partially within the drum of the multi-gravity separator. The multi-gravity separator separates the material into a second light fraction and a second heavy fraction. The second heavy fraction is substantially precious metals and copper.

[0007] A system for separating metals from a material, the system having a source of the material, wherein the material substantially contains incinerator-combined ash (includes both bottom ash and fly ash), automobile shredder residue, electronic scrap, and a combinations thereof, a size reducer, a magnet, a 2-stage screen that allows incinerator ash materials of about 0.001 to about 3 millimeters (mm) or less to pass through a first screen, falling velocity separator operating at greater than 5SG (specific gravity) (e.g., greater than 6SG or 7SG) a multi-gravity separator having a screw at least partially within the multi-gravity separator, wherein the multi-gravity separator separates the material into a second light fractionfraction and a second heavy fraction.

BRIEF DESCRIPTION OF DRAWINGS

[0008] FIG. 1 is a schematic view of a multi-gravity separator according to this disclosure.

[0009] FIG. 2A shows an exemplary multi-gravity separator with a screw feeder therein.

[0010] FIG. 2B shows an exemplary implementation.

[0011] FIG. 3 is a process flow diagram illustrating a method of material processing according to this disclosure. DETAILED DESCRIPTION

[0012] Specific embodiments of this disclosure include the use of a multi-gravity separator (e.g., Mozley) to recover metals from incinerator bottom ash, automobile shred residue, and waste electrical and electronic equipment/electronic scrap. The metals to be recovered include copper, zinc, lead, precious metals, and platinum group metals from fines. FIG. 1 shows a schematic separator 10, such as a centrifugal flowing-film separator or the like and, more specifically, such as a multi-gravity separator (MGS), commercially available from Richard Mozley Limited, U.K. for selectively separating particles based on differences in density and as such employs a density separation technique. The multi- gravity separator can be a centrifugal separator.

[0013] More specifically, this disclosure includes methods and systems for using multi- gravity separators to recover metals from fines between 1 micron and 2mm. In some examples, the fines can be between 0.005 mm and 1.8 mm. In other examples, the fines can be between 0.005 mm and 1 mm. In other examples the fines can be between 0.1 and 0.3 mm or in other examples, between about 1 micron and 2mm. In another example, the fines can be between 1 and 20 microns. In another example, the fine can be between 1 micron and 2 mm. A wet screen (200, 400, 600 or greater mesh) may be used prior to using the multi-gravity separator. In one embodiment, the method includes processing the fines of ASR, electronic scrap, or IBA using a multi-gravity separator.

[0014] While multi-gravity separators have a low capacity, the separator can be used to recover metals from these small particle sizes, which have been difficult to separate. The multi-gravity separator can take the place of other flotation and fine gravity separation processes and devices. Further, the multi-gravity separator may be used in addition to other separation processes. The multi-gravity separator can be used at the end of processing routes to maximize the recovery of metals.

[0015] FIG. 2A shows an exemplary multi -gravity separator 10 with a (screw) feeder 20 with an exemplary augur 40 therein. The placement of the (screw) feeder 20 inside a rotating drum 30 reduces water consumption and can achieve many times the normal gravitational pull on the particles as the materials move long the internal surface of the drum 30. The centrifugal field allows finer particles to be selectively separated than would be possible using conventional flowing-film separators because of the increased gravitational force that pins the higher density particles against the rotating drum. This schematic of a multi-gravity separator 10 has a housing 40 having a drum 30 mounted thereon potentially rotating at between 75-400 rpm, a peristaltic pump, inlets from the tank (e.g., water and material), and outlets to a concentrate (i.e., heavy fraction) supply and a tailings (i.e., a light fraction) supply. The housing of the separator is adjustable to an angle between 0 and 12 degrees relative to the surface on which the multi-gravity separator is positioned. A higher inclination increases the throughput capacity of the unit, but reduces the recovery of the metals. An acceptable trade-off between capacity and recovery is established by the operator for a recovery system. FIG. 2B shows the separators 10 with feeders 20 with feeding pipes 50 (for supplying material) in an exemplary implementation on a platform (P).

[0016] Referring to FIG. 3, an exemplary method 200 for processing materials is shown and described. In this example, the method for separating metals from a material includes providing the material 210, wherein the material substantially contains incinerator combined ash, automobile shredder residue, electronic scrap, and combinations thereof; reducing the size of the material 220; sizing the material using a screen (e.g., a one or 2- stage screen) to recover a first fraction about 0.001 to about 0.3/2mm 230; magnetically separating the material to recover ferromagnetic metals and paramagnetic metals 240; separating the first fraction using a first separator operating at about at SG or greater into a first heavy fraction and a first light fraction 250, wherein the first separator is falling velocity separator, a rising current separator or spiral separator (e.g., a jig) operating at about 5 SG or greater for separation; feeding the first light fraction into a multi-gravity separator 260 (e.g., the separators shown in FIGs. 1, 2A and 2B), wherein the multi- gravity separator separates the material into a second light fraction and a second heavy fraction; collecting second light fraction, and collecting the second heavy fraction, wherein the second heavy fraction is substantially metals or precious metals 270. These more valuable precious metals tend to have the highest specific gravity of any material.

[0017] At block 210, the incinerator ash may be combined with a liquid (e.g., water). At block 210 the material is separated using at least one 2-stage screen. Upon completion of separation of the incinerator combined ash, material sizes remaining in the system are preferably ranged between about 0.001 mm to about 3 mm. The materials can be segregated into discrete size ranges based on, e.g., commercially available equipment and specifications. As used herein, the term "screen" or "screening" refers to any process or apparatus used to separate a feed stream into at least two grades (e.g. different size cuts) and includes both dry screening and wet screening. Screening mechanism including but not limited to, vibrating screens, gyratory screens, moving screens, static screens, horizontal screens or inclined screens.

[0018] The size reducer 220 may be a ball mill, crusher, shredder, or like apparatus capable of reducing the size of the materials sent to the size reducer 220. Upon the materials being reduced in size, the materials may be sent back to the 2-stage screen 250 for further separation. Both crushing and grinding lead to size reduction of the material or to "comminution." Ball milling can be used to prepare powdered materials, e.g., materials greater than 35 or 50 mesh (e.g., about 100 mesh or 80 mesh).

[0019] At block 240 materials having about 5.0 SG are separated using at least one magnetic pulley/magnet. Exemplary magnetic pulleys include medium and high intensity pulleys. At the magnetic pulley(s), ferrous metals are removed from the about 5 SG or greater materials, leaving non-ferrous materials within the processing stream. Optionally, sensor sorter(s) can isolate out remaining metallic or metallic materials within the materials. These isolated metallic material may be crushed and re-processed according to the method 200 disclosed herein. Prior to arriving at the optical sorter, the materials may be washed at a washing tumbler (not illustrated).

[0020] The materials can be segregated into discrete size ranges based on, e.g., commercially available equipment and specifications. Exemplary and illustrative size ranges include about 0.001 to about mm, about 0.001 to about 2 mm, about 0.001 mm to about 0.3 mm. Exemplary and illustrative size ranges include about 0.001 to about 30 microns, about 0.001 to about 200 microns, about 0.001 mm to about 0.3 mm. Separation of the materials into discrete batch size ranges provides more effective processing at later processing stages of the system 100. More particularly, each fraction can be batched through system 100 to promote efficiency. In one embodiment, the ratio of the upper cut to lower cut may be less than 4.

[0021] Another embodiment includes a system for separating metals from a material, the system can have a source of the material (e.g., the material substantially contains incinerator combined ash, automobile shredder residue, electronic scrap, and a combinations thereof), a size reducer (e.g., ball mill or crusher), a magnet (e.g., high intensity or low intensity magnet, a scree that allows to pass, a falling velocity separator (e.g. a jig or spiral separator) operating 5SG or greater (e.g., 6SG, 7SG, 8SG, 9SG or greater), and a multi-gravity separator (e.g., having a screw at least partially within the multi-gravity separator). The multi-gravity separator separates the material into a second light fraction and a second heavy fraction. The parts and elements and operative connections are available to and known those with ordinary skill in the art.

[0022] It is contemplated that the rotational speed and tilt angle of the drum may need optimization. The rotational speed and the inclination of the drum are the operational parameters. Such optimization may improve output rates. The drum of the separator may be adjustable to an angle between 0 and 12 relative degrees to the surface. A higher inclination may increase throughput capacity and reduce the recovery of the metal. An optimal balance between the capacity and recovery is determined by the parameters of the overall process and system.

[0023] In certain embodiments, the metals may be precious metals or non-precious metals. In one example, a precious metal is a rare, naturally occurring metallic chemical element of high economic value. Chemically, precious metals tend to be less reactive than most elements (see noble metal). They are usually ductile and have a high luster. Historically, precious metals were important as currency but are now regarded mainly as investment and industrial commodities. In one example, gold, silver, platinum, and palladium each have a currency code and are considered precious metals. Precious metals have a specific gravity higher than 5 SG.

[0024] Examples of multi-gravity separators are attached hereto and are known in the art. The operating principle of the multi-gravity separation is achieved by passing a flowing film of water and/or slurry over a stratified layer of particles such that larger and lower specific gravity particles are preferentially carried along by the flowing film which is collected separately, while higher specific gravity particles which remain near the surface of the table are carried along in a different direction by other physical means. Generally, larger and higher specific gravity particles report to the underflow at the apex of the cyclone, while smaller and lower specific gravity particles report to the overflow at the opposite end of the cyclone/drum. This process facilitates a higher probability of finding and extracting these precious metals relative to conventional processes.

[0025] The result of the method/process includes recovered metals with a high purity. An advantage of the system with a multi-gravity system with a direct screw feeder is that it allows high levels of precious metals can be recovered from materials have flat and wire shapes.

[0026] Although specific embodiments of the disclosure have been described above in detail, the description is merely for purposes of illustration. It should be appreciated, therefore, that many aspects of the disclosure were described above by way of example only and are not intended as required or essential elements of the disclosure unless explicitly stated otherwise. Various modifications of, and equivalent steps corresponding to, the disclosed aspects of the exemplary embodiments, in addition to those described above, can be made by a person of ordinary skill in the art, having the benefit of this disclosure, without departing from the spirit and scope of the invention defined in the following claims, the scope of which is to be accorded the broadest interpretation so as to encompass such modifications and equivalent structures.

Claims

1. A method for separating metals from a material, the method comprising: a. providing the material, wherein the material substantially contains incinerator combined ash, automobile shredder residue, electronic scrap, or a

combinations thereof;

b. reducing the size of the material;

c. magnetically separating the material to recover ferromagnetic metals and paramagnetic metals;

d. sizing the material using at least one 2-stage screen to recover a sized fraction about 0.001 to about 2mm or less;

e. separating the material at about 5 SG or greater using a gravity separator into a first heavy fraction and a first light fraction;

f. feeding the first light fraction into a multi-gravity separator having a drum and a screw at least partially within the drum of the multi-gravity separator, wherein the multi-gravity separator separates the material into a second light fraction and a second heavy fraction;

g. collecting the second heavy fraction, wherein the second heavy fraction is substantially precious metals and copper.

2. The method of claim 1, wherein the material is sized reduced by a ball mill.

3. The method of claim 1, wherein the multi-gravity separator is a density- based enhanced gravity separator.

4. The method of claim 3, wherein the metals are substantially gold and copper.

5. The method of claim 1, wherein the metals are substantially precious metals.

6. The method of claim 1, the metals are at least one of brass, lead, cadmium, mercury, uranium, gold, silver, antimony, rare earth elements, precious metals, nonmagnetic stainless steel, metals having an atomic weight of greater than 58, or alloys

7. The method of claim 1, wherein the multi-gravity separator comprises a centrifugal separator.

8. The method of claim 1, wherein the metal content of the incinerator combined ash, automobile shredder residue, or electronic scrap is greater than 4% and the second light fraction is less than 0.1% prior to feeding into the multi-gravity separator.

9. The method of claim 2, wherein the first separator is a jig.

10. The method of claim 1, separating the sized fraction using the separator operating at greater than about 5 SG into a first heavy fraction and a first light fraction, wherein the gravity separator is a rising current separator or spiral separator operating at greater than about 5 SG for separation.

11. A system for separating metals from a material, the system comprising: a. a source of the material, wherein the material substantially contains incinerator combined ash, automobile shredder residue, electronic scrap, and a combinations thereof,

b. a size reducer,

c. a magnet, d. a 2-stage screen that allows incinerator ash materials of about 0.001 to about 3 millimeters (mm) or less to pass through the screen,

e. a falling velocity separator operating at greater than 5 SG, and

f. a multi-gravity separator, wherein the multi-gravity separator separates the material into a second light fraction and a second heavy fraction.

12. The system of claim 11, wherein the size reducer is selected from the group consisting of a ball mill, a crusher, and shredder.

13. The system of claim 11, wherein the magnet has strength greater than 2000 gauss.

14. The system of claim 12, wherein the falling velocity separator is a jig.

15. The system of claim 14, wherein the multi-gravity separator is a density- based enhanced gravity separator.

16. The system of claim 12, wherein the falling velocity separator is a jig.

17. The system of claim 14, wherein the material is with water.

18. The system of claim 17, wherein the multi-gravity separator has a screw at least partially within the multi-gravity separator.

19. The system of claim 17, wherein the separator operates at greater than 6

SG.