Precious and Critical Metals Recycling at the Kroll

Precious and Critical Metals Recycling at the Kroll Institute for Extractive Metallurgy Dr. Corby G. Anderson Harrison Western Professor Kroll Institute for Extractive Metallurgy George S. Ansell Department of Metallurgical and Materials Engineering Colorado School of Mines IPMI 42nd Annual Meeting June 12, 2018 : San Antonio, Texas

Colorado School of Mines • • • • •

Est. 1874 Golden, Colorado 3 Colleges & 21 Technical Majors About 200 Faculty About 5500 Students

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“…has a unique mission in energy, mineral, and materials science and engineering…” “has the some of the most stringent admission standards of any US public engineering school.” “ranked #1 in the World for Mining and Mineral Engineering” by Business Insider.” “Ranked as #1 US Engineering school” by USA Today.” “QS Global Ranking: #1 in Mineral and Mining Engineering.” “Colorado School of Mines was ranked first in the nation by The Wall Street Journal/Times Higher Education College Ranking for public schools that do the best in combining scholarly research with classroom instruction.” “The average starting salary of a BSc Mines graduate is about $ 10 K more than an Ivy League graduate.”

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IPMI 42nd Annual Meeting June 12, 2018 : San Antonio, Texas

3 DAY SHORT COURSE 26th Annual Recycling Metals From Industrial Waste Colorado School of Mines Golden, Colorado USA A Short Course and Workshop with Emphasis on Plant Practice

http://csmspace.com/events/recycmetals/ Colorado School of Mines Golden, Colorado June 26 -28, 2018


1 DAY CR3 SPECIAL SESSION INVITE 8thth Annual Center for Resource Recovery & Recycling

An NSF Industry / University Cooperative Research Center (I/UCRC)

Colorado School of Mines Golden, Colorado USA June 28, 2018


4 DAY SHORT COURSE 35th Annual New Directions in Mineral Processing Fundamentals The course will emphasize the unit operations utilized in industry and their application to operations. Topics covered will include: Characterization (mineralogy, size, liberation) Analysis of separation efficiency Size reduction Separations based on particle size, density, floatability, magnetic susceptibility, conductivity Solid-liquid separations Materials handling http://csmspace.com/events/minproc/ Colorado School of Mines Golden, Colorado July 17- 20, 2018


5 DAY SHORT COURSE


kiem.mines.edu


KROLL INSTITURE FOR EXTRACTIVE METALLURGY

Dr. William Justin Kroll was a Luxembourg metallurgist. He is best known for inventing the Kroll process in 1940, which is used commercially to extract metallic titanium from ore. Born: November 24, 1889, Luxembourg Died: March 30, 1973, Brussels, Belgium First TMS EPD Distinguished Lecturer in 1959

“good metallurgists are not born. They are made with the ample money of the companies which hire them, and since they usually make their mistakes on a grand scale, they are the nightmares of business management.” 1943 Perkin Award Speech Quotation by Dr. William Kroll


KROLL INSTITURE FOR EXTRACTIVE METALLURGY

“KIEM - Excellence in Education and Research for the Mining, Minerals and Metals Industries”

• History: The Kroll Institute for Extractive Metallurgy was established at the Colorado School of Mines in 1974 using a bequest from Dr. William J. Kroll after he died. • This effort was led by Professor Al Schlechten. For over 40 years, the Kroll Institute has provided support for a significant number of undergraduate and graduate students who have gone on to make important contributions to the mining, minerals and metals industries.

 Objectives: The objectives of KIEM are to provide research expertise, well-trained engineers to industry, and research and educational opportunities to students, in the areas of : minerals processing, extractive metallurgy, recycling, and waste minimization.


The Kroll Institute for Extractive Metallurgy

Dr. Patrick R. Taylor, Director KIEM George S. Ansell Department of Metallurgical & Materials Engineering, Colorado School of Mines


CENTER FOR RESOURCE RECOVERY AND RECYCLING (CR3)

An NSF Industry/University Cooperative Research Center Four International Universities and Seventeen Industry Partners.


CENTER FOR RESOURCE RECOVERY AND RECYCLING

(CR3) Industrial Members Aurubis AG East Penn Manufacturing Gopher Resources Hydro Aluminum Rolled Products GmbH Indium Corporation JX Nippon Mining Metallo‐Belgium SMS Group Steinert Surface Combustion Tianqi Lithium Corporation Umicore Group U.S. Army Research Laboratory Global Mineral Recovery General Motors


(CR3) Example Research Projects 1 ‐ Development of Aluminum‐Dross Based Materials for Engineering Application (2011) 2 ‐ Physical and Chemical Beneficiation for Recycling of Photovoltaic Materials (2011) 3 ‐ Recovery of Rare Earth Metals from Phosphor Dust (2011) 4 ‐ Recycling of Bag‐House Dust from Foundry Sand (2011) 5 ‐ Molten Metal Compositional Sensing to Enhance Scrap Recycling (2012) 6 ‐ Rare‐Earth Recovery from Magnets, Catalysts, and Other Secondary Resources (2012) 7 ‐ Resource Recovery and Recycling from Shredder Residue in North America (2012) 8 ‐ Recovery of Eu/Y from Phosphor Dust (2013) 9 ‐ Conditioning of Machined Chips (2013) IPMI 42nd Annual Meeting June 12, 2018 : San Antonio, Texas

(CR3) Example Research Projects 10 ‐ Beneficiation of Flat Panel Functional Coatings (2013) 11 ‐ Metal Recovery via Automated Sortation (2013) 12 ‐ Recovery of Value‐Added Products from Red Mud and Foundry Bag House Dust (2013) 13 ‐ Dezincing of Galvanized Steel (2014) 14 ‐ Development of a Novel Recycling Process for Li‐Ion Batteries (2014) 15 ‐ Fundamental Study of Lithium Ion Battery Recovery (2014) 16 ‐ Magnet Separation Technologies for Recycling (2015) 17 ‐ Recovery of Zinc and Iron from EAF Dusts (2015) 18 ‐ Synthesis of Inorganic Polymers from Metallurgical Residues (2015)

Proprietary Information-dissemination and use restricted members of the Center for Resource Recovery and Recycling IPMIto 42nd Annual Meeting

June 12, 2018 : San Antonio, Texas

(CR3) Recent Research Projects 19 ‐ Recovery of Valuable Metals from Fines (2016) 20 ‐ Value Recovery from Mining Wastes (2016) 21 ‐ Reuse Opportunities for Bauxite Residue (2017) 22 ‐ Rare Earth Metals Recovery from Bauxite Residue (2016) 23 ‐ Scrap Characterization (2017) 24 ‐ Battery Design for Disassembly in Support of Materials Reuse (2017) 25 ‐ Hydrometallurgical Treatment of e‐Scrap (2017) 26 ‐ Recovery of Valuable Metals from Mechanical Treatment of e‐Scrap (2017) 27 ‐ Online Slag and Bullion Analysis by LIBS (2017) 28 – Automobile Paint Sludge Recycling (2017) 29 ‐ Vacuum Refining of Recycled Lead (2017) 30 ‐ Recovery of Antimony (2017) IPMI 42nd Annual Meeting June 12, 2018 : San Antonio, Texas

Recycling of Zinc from Galvanized Steel


Background Galvanized steel, or zinc coated steel, is used for its corrosion resistant properties. It provides lower cost corrosion resistance than stainless steels and is useful in numerous applications, for example steel. In 2012 there were 3.4 million tons of galvanized steel produced in the USA. Its use is so ubiquitous it’s the main driver of zinc demand, with 85% of the zinc consumed in the USA used for galvanizing. IPMI 42nd Annual Meeting June 12, 2018 : San Antonio, Texas

Project Objectives & Deliverables Objectives: Develop process to economically produce dezinced ferrous scrap from galvanized steel Recover a saleable zinc product from the galvanized steel Incorporate reagent recovery technologies in flowsheet to minimize waste Engage in PhD level research

Deliverables An economic dezincing process for galvanized steel IPMI 42nd Annual Meeting June 12, 2018 : San Antonio, Texas

Key Accomplishments Examined incorporating shredding into flowsheet Looked at alternative reactor materials to stainless steel Determined mass transfer properties of various membranes Related fundamental mass transport properties to the results of the bench scale unit  Completion of Discounted Cash Flow analysis Patent granted June 2018 IPMI 42nd Annual Meeting June 12, 2018 : San Antonio, Texas

Lab Scale Leaching • Leaches on fresh galvanized material to examine the fundamentals of the dezincing process • Rates determined through H2 evolution


Simplified Flowsheet H2SO4 Top up

Water Recovered Acid

Zinc Coated Scrap Cleaned and degreased. Can be shredded dependant on particle size

Liquid/Solid Separation Galvanised Steel Leach Steel dissolution minimised using Eh control and/or inhibitors

Acid Recovery

Purification/Recovery Crystallization or precipitation

Free acid is recovered by diffusion dialysis in an anionic membrane stack

Dezinced Scrap Zinc Product & minor Fe and other impurites

“Feed and bleed” leach with solution purification/recovery IPMI 42nd Annual Meeting June 12, 2018 : San Antonio, Texas

Economic Sensitivity Analysis  A decrease in the price differential between galvanized and ferrous scrap would impact the project economics greatest


Recycling of Tellurium


Introduction Source tellurium by recovery using alkaline sulfide leaching on recycled solar panels and gold concentrates.  Tellurium is rare (3 parts per billion in crust) and is gaining popularity

for application to photovoltaic Cd-Te films in solar cells.  The global annual production of tellurium is 450 metric tonnes and is largely a byproduct of copper electrorefining. It is a Critical Material.  Gold telluride is difficult to process with cyanidation.  Alkaline sulfide leaching (Na2S and NaOH) is a selective and inexpensive leaching method.


Background Results - MLA and Chemical Analysis (Float Con)

Native Gold locked in quartz IPMI 42nd Annual Meeting June 12, 2018 : San Antonio, Texas

Gold telluride (Calaverite)

Background


Flowsheet


Economic Analysis

28 IPMI 42nd Annual Meeting June 12, 2018 : San Antonio, Texas

Recycling of Li Ion Batteries


Battery Overview Composition      

7% Plastics (casings) 15% Organic chemicals (electrolytes) 5-7% Lithium 20% Cobalt 5-10% Nickel 8-9% Copper

Components  Iron-nickel casing which contains:  Negative electrode (typically made of graphite)  Positive electrode (metal oxide, typically lithium cobalt oxide, lithium iron phosphate, or lithium manganese oxide)  Electrolyte (mixture of organic carbonates which contain complex lithium ions)

Secondary batteries contain no elemental lithium, therefore, reactivity is at a minimum when battery is discharged. IPMI 42nd Annual Meeting June 12, 2018 : San Antonio, Texas

Current Processes Hydrometallurgical approach  Toxco in Trail, British Columbia  Immerse batteries in salt water and cryogenically freeze before comminution  LiOH is used to bring pH to 10 or above  Then it is leached with sulfuric acid  Li compounds form during reaction and precipitate from solution  Salts are filter pressed and lithium is recovered by dewatering and adding CO2  Recovery of lithium is 97%

Pyrometallurgical approach  Umicore in Hofors, Sweden  No comminution needed - batteries, coke, and flux are thrown into shaft furnace  Three temperature zones  Preheating zone  Pyrolizing zone  Smelting and reducing zone

 100% of lithium is claimed to be in slag phase  Recovery of nickel is 100% and recovery of cobalt is 96%


Experimentation Leaching Design

Experimental Matrix

 Wanted to test using two different acids  Hydrochloric  Sulfuric

 Wanted to test three parameters:  Time  Temperature  Concentration

 Computer software was used for design of experiments to optimize testing parameters

Test

Time

Temp.

Conc.

(min)

(°C)

Normality

10

30

30

1

9

90

30

1

1

30

90

1

2

90

90

1

8

30

30

5

7

90

30

5

4

30

90

5

3

90

90

5

5

60

60

3

6

60

60

3


Results Sulfuric Nickel Recovery (related to time and temperature)

Hydrochloric Nickel Recovery (related to time and temperature)


Economic Analysis Year Net Revenue Salvage Value Operating Costs Depreciation Amortization Taxable Income 40% Taxes Net Income Depreciation + Amortization + Capital Expenses After Tax Cash Flows (ATCF) Discounted ATCF @ 6% Cummulative Discounted ATCF

0

1 $ 182,858,865.00 $ $ (102,822,400.31) $ (1,267,659.81) $ (2,028,255.69) $ 76,740,549.19 $ (30,696,219.68) $ 46,044,329.52 $ 1,267,659.81 $ 2,028,255.69 $ $ 49,340,245.02 $ 46,547,587.15 $ 23,744,466.89

$ $ $ $ $ $ $ $

(36,890.69) (36,890.69) 14,756.28 (22,134.42)

$ $ $ $ $

36,890.69 (22,817,876.53) (22,803,120.25) (22,803,120.25) (22,803,120.25)

Net Present Value (i=6%) Rate of Return Payback (years)

$ 187,734,269.25 $ (21,569,369.54) 36.5% 0.49

2 $ 182,858,865.00 $ $ (102,822,400.31) $ (2,281,787.65) $ (2,028,255.69) $ 75,726,421.35 $ (30,290,568.54) $ 45,435,852.81 $ 2,281,787.65 $ 2,028,255.69 $ $ 49,745,896.15 $ 44,273,847.58 $ 68,018,314.47

3 $ 182,858,865.00 $ $ (102,822,400.31) $ (1,825,430.12) $ (2,028,255.69) $ 76,182,778.88 $ (30,473,111.55) $ 45,709,667.33 $ 1,825,430.12 $ 2,028,255.69 $ $ 49,563,353.14 $ 41,613,391.30 $ 109,631,705.77

4 $ 182,858,865.00 $ $ (102,822,400.31) $ (1,460,344.10) $ (2,028,255.69) $ 76,547,864.90 $ (30,619,145.96) $ 45,928,718.94 $ 1,460,344.10 $ 2,028,255.69 $ $ 49,417,318.73 $ 39,143,458.17 $ 148,775,163.94


5 $ 182,858,865.00 $ 2,281,787.65 $ (102,822,400.31) $ (5,841,376.39) $ (1,014,127.85) $ 75,462,748.11 $ (30,185,099.24) $ 45,277,648.87 $ 5,841,376.39 $ 1,014,127.85 $ $ 52,133,153.10 $ 38,959,105.31 $ 187,734,269.25

Recycling of Critical Materials from Lead Battery Wastes


Lead Battery Recycling Background Recycling of critical/precious metals has become significant in the past decade as known sources of these metals are depleting Gopher Resources (Our Sponsor), a leadbased battery recycler, produces 99.95 % pure lead or special lead alloys through their refining process Drossing, a process used to remove impurities like Copper, is currently used by Gopher Resources


Lead Battery Recycling Background ● Caustic dross addition is meant to remove As & Sb ● Sulphur drosses remove Cu impurities ○ No specified step for Ni removal ● This Gopher Resources project focused around leaching of the impurities present after Caustic Drossing


Analysis of As-Received Cold Caustic Wash Material


Experimental Method Leach experiments tested four factors:    

Residence Time: From 4 hours to 8 hours Temperature: From 25 to 75 degrees celsius Sulfuric Acid Concentration: From 20 to 50 g/L Hydrogen Peroxide: From 0 to 10 g/L

Design Expert was used to generate runs for a 24-1 factorial design with 3 midpoints


Process Design Criteria- Flow Sheet ● 10 tons of CCW per day ○ 2 leach vessels (each 10,000 gallons) ○ 20 wt. % solids for leach ○ Production of Cu/Ni Carbonates ○ Production of iron arsenates IPMI 42nd Annual Meeting June 12, 2018 : San Antonio, Texas

Non Cyanide Recycling of Silver


Nitrogen Species Catalyzed Leaching Fundamentals 3 MeS (S)+ 2HNO3 (Aq)+ 3H2SO4 (Aq)  3 MeSO4 + 3So (S) + 2NO (G) + 4H2O NaNO2

(Aq)

+ H+  HNO2 (Aq) + Na+

HNO2

(Aq)

+ H+  NO+ (Aq) + H2O

2MeS (S) + 4NO+ (Aq)  2Me+2 (Aq) + 2So + 4NO (G)


Nitrogen Species Catalyzed Leaching Fundamentals Relative Potentials of Hydrometallurgical Oxidizers. E0h Oxidant Redox Equation (pH = 0, H2 ref.) Fe+3

Fe+3 + e-  Fe+2

0.770 V

HNO3

NO3- + 4H+ +3e-  NO(g) + 2H2O

0.957 V

HNO2

NO2 - + 2H+ + e-  NO(g) + H2O

1.202 V

O2 (g)

O2 + 4H+ + 4e- 2H2O

1.230 V

Cl2 (g)

Cl2 (g) + 2e -  2 Cl-

1.358 V

NO+

NO+ + e-  NO(g)

1.450 V


Nitrogen Species Catalyzed Silver Leaching Kinetics


AgCl Precipitation

Ag+ + NaCl (Aq)  AgCl (S) + Na+


AgCl Reduction Reactions Na2CO3

(S)

+ H2O ----> NaHCO3

(Aq)

+ NaOH

AgCl (S) + NaOH (Aq) ---> AgOH (S) + NaCl 2AgOH (S) + Heat ---> 12Ag2O (S) + C6H12O6

(Aq)

Ag2O(S) +

(Aq)

(Aq)

H2O

---> 24Ago + 6CO2 (G) + 6H2O


Non Cyanide Silver Industrial Flowsheet


Non Cyanide Recycling of Gold


Why Make a Change from Cyanide?  Cyanide works great, right? Unfortunately…  Increased environmental scrutiny  Refractory ore bodies  Carbonaceous, pyritic, arsenical, or cyanide consuming copper ores and concentrates.  Double refractory ores and concentrates.  Address with either roasting or pressure oxidation but roasting is under scrutiny as well due to Hg IPMI 42nd Annual Meeting June 12, 2018 : San Antonio, Texas

Alkaline Sulfide Gold Leaching System Leach gold from with alkaline sulfide solutions Benefits: System selectively leaches gold Elemental sulfur may be provided from the partial oxidation of sulfide


Electrochemical Review Two reactions: Oxidation and Reduction Au  Au+ + eSx2- + 2e-  Sy2(where y = x-1)  Electromotive potential: Where total current transfer = 0  Leaching phenomenon: A measure of kinetics How fast does a reaction occur at the Em Leach rate is what really matters Gold Oxidation: Polysulfide reduction:


ASL Pilot Plant


Hydrometallurgical Recycling of Printed Circuit Boards


Background  41.8 million tonnes e-scrap was generated, and it is expected that the amount of e-scrap will reach to 49.8 million tonnes in 2018 with annual growth of 4% to 5%.  E-scrap contains plastic and various metals, including precious and base metals.  There are two reasons for recycling of e-scrap:  Economic potential of recycling precious and base metals  Facilitate environmental and human health risks  Hydrometallurgy offers better and direct selectivity for metals recovery  Patent application being filed IPMI 42nd Annual Meeting June 12, 2018 : San Antonio, Texas

Background 10

60

Population 9

40 8 30 7 20

6

10

0

5

2010

2011

2012

2013

2014 year

2015

2016

2017

2018

Figure 1. Global e-waste generation from 2010 to 2018.


Population (billion)

Amunt of E-waste (million tonnes)

Amount of E-waste 50

Background Representative material composition of PCBs Metallic element

Birloaga et al. 2013 [2]

Yang et al. 2009 [3]

Oishi et al. 2007 [4]

Behnamfard et al. 2013 [5]

Cu (wt%) Al (wt%) Fe (wt%) Sn (wt%) Ni (wt%) Zn (wt%) Pb (wt%) Mn (wt%) Sb (wt%) Au (ppm) Ag (ppm)

30.57 11.69 15.21 7.36 1.58 1.86 6.70 238 688

25.06 4.65 0.66 1.86 0.0024 0.04 0.80 -

26 3.2 3.4 4.9 1.5 2.6 3.0 0.11 0.16 -

19.19 4.01 1.13 0.69 0.17 0.84 0.39 0.04 0.37 130.25 704.31


Background Fig.1 MLA image from the printed circuit board residual material

Fig. 2 BSE image from the printed circuit board residual material


Background Comparison of potential leaching reagents for base metals [16,17,18,19] Sulfuric acid Chloride

Aqua regia Ionic liquids

Pros Cons Highly selective, low reagent At elevated temperature, cost, well established process for corrosive copper ore Fast kinetics at room Excessive corrosion, temperature, high solubility and difficult electrowinning of activity of base metals, low copper, poor quality of toxicity copper Fast kinetics, effective High reagent cost, highly corrosive, low selectivity Thermally stable, High cost, excessive environmentally friendly dosage


Background Comparison of potential leaching reagents for gold [16,20,21] Pros

Cyanide Thiourea Thiosulfate Halides Aqua regia

Cons Difficult to process Highly effective, low reagent wastewater, environmental dosage and cost risk, low kinetics Poorer stability, high Less toxic, high reaction rate, less consumption, more expensive than cyanide, downstream interference ions metal recovery High consumption of reagent, High selectivity, non-toxic and non-corrosive, fast leaching rate downstream metal recovery High leaching rate, high selectivity, relatively healthy and safe except for bromine

Highly corrosive for chlorine, high consumption for iodine

Strongly oxidative and Fast kinetics, low reagent dosage corrosive, difficult to deal with downstream


Summary

KIEM – “Excellence in Education and Research for the Mining, Minerals and Metals Industries for 44 years continues in Recycling.”


Thank you for this opportunity to present once again here in my 31st year with IPMI. Questions ? IPMI 42nd Annual Meeting June 12, 2018 : San Antonio, Texas

Precious and Critical Metals Recycling at the Kroll Institute for Extractive Metallurgy Dr. Corby G. Anderson Harrison Western Professor Kroll Institute for Extractive Metallurgy George S. Ansell Department of Metallurgical and Materials Engineering Colorado School of Mines IPMI 42nd Annual Meeting June 12, 2018 : San Antonio, Texas