RECYCLING ELECTROCHEMICAL MACHINING FOR METAL RECOVERY … files/Publications/ECS 2015 Spring... ·...

RECYCLING ELECTROCHEMICAL MACHININGFOR METAL RECOVERY AND ELIMINATION OF WASTE

Brian T. Skinn

Faraday Technology, Inc.

227th Meeting of the Electrochemical Society

Chicago, IL

Co-Authors

Savidra C. Lucatero, Stephen T. Snyder , E. Jennings TaylorTimothy D. Hall, Heather A. McCrabb, Holly G. Garich, Maria Inman

May 26, 2015

[email protected]

Outline

Applied Electrochemistry

Scope

Conventional vs. Pulse/Pulse-Reverse (P/PR)

Recycling Electrochemical Machining

ECM: Problem & Opportunity

(R)ECM Concept & System Design

Results to Date

227th ECS - B Skinn - 26 May 20152


Red n e + Ox

+

Electronic Current

Ionic Current

Anode Cathode

Current is net flow ofPOSITIVE CHARGE



Red n e + Ox

+

Electronic Current

Ionic Current

Anode Cathode


e Anode

Reactions

M0 n e + Mn+

S n e + Sn+

2 H2O 4 e + 4 H+ + O2



Red n e + Ox

+

Electronic Current

Ionic Current

Anode Cathode


e Anode

Reactions

M0 n e + Mn+

S n e + Sn+

2 H2O 4 e + 4 H+ + O2

Material Processing

Anodic (subtractive)

Electropolishing

Cathodic (additive)

Electroplating

Solute Modification

Anodic / Cathodic

Chlor-alkali

Water Electrolysis

Anodic / Cathodic

H2 productionBubble generation


C

X=0 Distance from electrode

x

Cb

Nernst Diffusion Layer Model

C


x

Cb


Cb

C


x

Cb


C


x

Cb


Cb

Linearized Concentration Profile

Pulsed Waveforms vs DC

Time

(+)

(-)

Know:DC


DCC


x

Cb


C


x

Cb


Cb

C


x

Cb


C


x

Cb


Cb

Linearized Concentration Profile

Pulsed Waveforms vs DC

Time

(+)

(-)

Know:

7

PC


DC

Distancex

Cx,t

t1

t2

t3

t4

x = 0

Co

t1 < t2 < t3

Copper Electrodeposition for Circuit Boards

Standard DC Recipe

CuSO4H2SO4

Accelerator

Suppressor

Leveller

Other Additives

Pulsed Waveform

Recipe

CuSO4H2SO4

Trace Cl

Trace PEG

Plante, et al. Quantization and Characterization of Copper Plating Bath Additives by Liquid

Chromatography with Charged Aerosol Detection. Thermo Scientific. http://www.dionex.com/en-

us/webdocs/113469-Pittcon12_1820-6_MPlante_PN70008_PlatingBaths.pdf


Polishing of Nb Superconducting RF Cavities

Polishing of 100m of inner cavity surface Remove flaws from sheet rolling

Nb metal Natural 5 nm Nb2O5 passivating layer Believed to be onlydissolved by HF

Buffered Chemical Etching Electrolytic Polishing1 part 48% HF or 1 part 48% HF1 part 65% HNO3 9 parts 96% H2SO42 parts 85% H3PO4

Traditional (Electro)chemical Practice


Polishing of Nb Superconducting RF Cavities

Traditional Electrolytic Polishing FARADAYIC Polishing1 part 48% HF 5-10% H2SO49 parts 96% H2SO4 Balance H2O


FARADAYIC Advantage

Problem/Opportunity

Electrochemical Machining (ECM)

Electrochemical Machining

+


Electrochemical Machining

1) Applicability to hard and difficult to cut materials

2) No tool wear

3) No surface damage

4) Controlled material removal rate

5) Smooth, bright surface finish

6) Production of parts with complex geometry

Conventional ECM Reactions:

Anode: M0 M+ + e-

Cathode: H2O + e- 1/2H2 + OH

-

Overall: M0 + H2O M(OH) + 1/2H2[M(OH) Sludge]

K.P. Rajukar, D. Zhu, J.A. McGeough, J. Kozak, A. De Silva, New Developments in Electro-Chemical Machining Annals of the CIRP Vol 82(2) 1999.


ECM Problem/Opportunity

Rifling (ECM) 5 gun barrel:

~250 in3 (4.1 dm3) metal removed

~350 gal (1300 L) centrifuged sludge

(~80,000 in3 centrifuged sludge)

~300x volume increase

U.S. Army Vision for Net Zero

1) Reclaim valuable materials and eliminate landfill discharge

2) Water conservation

3) Minimize energy usage by elimination of filtration, centrifugation and shipping of sludge

Rajukar Pkey challenge for ECMPis waste product management.

Wessel, Electrochemical Machining of Gun Barrel Bores and Rifling, Naval Ordnance Station, Louisville KY, September 1978. http://handle.dtic.mil/100.2/ADA072437


Concept and System Design


Patents Pending: U.S. 62/114,278 (10 Feb 2015) and U.S. 62/120,621 (25 Feb 2015)

Conventional ECM Reactions: P/PR ECM Reactions:

Anode: M0 M+ + e- Anode: M0 M+ + e-

Cathode: H2O + e- 1/2H2 + OH

- Cathode: H+ + e- 1/2H2

Overall: M0 + H2O M(OH) + 1/2H2 Overall: M0 + H+ M+ + 1/2H2

M(OH) Sludge M+ Soluble metal ions Electrowinning

Electrolyte selected so that metal remains soluble (M+) after ECM and

is suitable for electrowinning, while maintaining surface finish

(using P/PR ECM)

(R)ECM Concept Electrochemistry

P/PR ECM enables electrolyte flexibility such that the ECM electrolyte

is the same as that used in the electrowinning operation.


(R)ECM Concept System Design

Conceptual Process Flow

Diagram

EWCathode:

2M2+ + 4e- 2M0

4 H+ + 4 e- 2 H2

Anode:2H2O O2 + 4H

+ + 4 e-

ECMWork piece:

2M0 2M2+ + 4e-

2H2O O2 + 4H+ + 4 e-

Tool:4 H+ + 4 e- 2 H2


Ford Power Train

Carbon steel (SAE 1010) planetary carrier Burrs in oil grooves (boring/milling) Manual removal

o $2,100,000 per year costo Intangible cost - quality, worker injury

K. Stacherski Electrochemical Deburring Ford PowerTrain Cutting Tool News 2(1) Winter 1996 (available www.FaradayTechnology.com)

Pulsed ECMo $1,600,000 capital cost

~$400k less for FARADAYIC Process

o Not chilledo Makeup water twice a montho Electrolyte replaced every six monthso Iron hydroxide removal magnetic separator

Prior Work Pulsed ECM


Evaluation of pulsed fields on silver recovery for Swagelok

Improved removal efficiency and adhesion vs direct current (DC)

Ag: ~200 ppm < 1 ppm

Ni: 322 ppm 171 ppm

Fe: 14.2 ppm 3.8 ppm

Cu: 2.2 ppm 0.05 ppm

Cd: 2 ppm 0.02 ppm

Cr: 4 ppm 0.3 ppm

Pb: 29 ppm 0.13 ppm

Zn: 5 ppm 0.3 ppm

Figure 22: Cathode with silver

Prior Work Pulsed Electrowinning


(R)ECM System

Pilot-Scale Design CustomElectrowinning Cell


Hole-Drilling ECM

Results


Materials of interest are suitable for (R)ECM processingPhase I project Prior activity at Faraday Literature sources

AlloyMajor

ComponentsFARADAYIC ECM FARADAYIC Electrowinning

C18000 CuPrinted Circuit Board Etching

Metallized Wafer Planarization

Phase I Work

FARADAYIC ElectroCell

SAE4150 FePhase I Work

Bipolar Plate EtchingLiterature

IN718 Ni / Cr / FePhase I Work

Molehill Removal

Phase I Work (Ni)

Trivalent Chromium Plating

Literature

SS316L Fe / Cr / NiSemiconductor Valve Polishing

Bipolar Plate Etching

Phase I Work (Ni)

Trivalent Chromium Plating

Literature

Ta10W Ta / W Literature (90:10 H2SO4:HF)CHALLENGE: Not demonstrated

in aqueous solution

Materials of Interest


FARADAYIC (R)ECM Development

11 Screen electrolytes for electrowinning performance

22 Test ECM performance of electrolyte from (1)

33 Electrowin electrolyte from (2)

44 Integrated (R)ECM system testing

FARADAYIC

ECMFARADAYIC

ElectroWinning


C18000 Pulsed ECM

ECM EW

2.5cm x 2.5cm C18000 alloy coupon

Electrolyte

NaNO3 + NH4NO3 + HNO3

Waveform

10 V || 100 Hz || 20-80% Duty Cycle

Forward pulse only


C18000 Electrowinning of ECM Electrolyte

Relative Current Density

Prepared Electrolyte

(770 ppm Cu2+)

ECM Electrolyte

ECM EW


C18000 (R)ECM Integration Testing

ECM EW

ECM EW


C18000 (R)ECM Integration Testing

ECM EW


ECM EW

SAE4150 (R)ECM Integration Testing

ECM EW


ECM EW

IN718 (R)ECM Integration Testing


ECM EW

ECMEW

SS316L Preliminary Development


0.15 m Ra

EW

Ta/Ta10W Polishing Demonstration


Ta10W Pure Ta

Final Ra (m) 0.04 0.06

Linear ECM Rate (m h1) 142 115

Pulse-Reverse

FARADAYIC Waveform

Summary

FARADAYIC (R)ECMECM with integrated metals recovery

Leverages electrolyte flexibility afforded by

FARADAYIC waveforms

Complete recycle of electrolyteMinimal losses from electrolysis,

dragout, etc.

Demonstrated for: C18000 (Cu-Ni-Cr)

SAE4150 (Cr-Mo alloy steel)

IN718 (Ni-Cr-Fe superalloy)

Other materials in developmentSS316L, Ta10W

FARADAYIC

ECMFARADAYIC

ElectroWinning


Acknowledgments

EJ Taylor, T D Hall, S Lucatero, S Snyder, H Garich, M Inman

This material is based upon work supported by the United States Army (contract #W15QKN-12-C-0010 and #W15QKN-12-C-0116) and the US Environmental Protection Agency (contract #EP-D-13-040). Any opinions, findings, conclusions and recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the US Army or the US EPA.

Contact Information:Brian T. Skinn

Ph: +1 937 836 7749

Email: [email protected]


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