Titanium Electrowinning Process Case Western Reserve University (PI: Rohan Akolkar) August 24 – 25, 2016 Detroit, MI METALS Annual Meeting sponge Proposed Ti C Electrowinning electrolysis Cl2 + TiO2 CO2 + TiCl4 Process Cl2 Outline ‣ Team Intro ‣ Technical Concept ‣ Technical Progress to date ‣ TEA Highlights ‣ Future Goals ‣ Q&A 1 Case Western Reserve University ‣ Case Western Reserve University Team Members: PI: Rohan Akolkar Personnel: Dai Shen, Stephen Banik, Mirko Antloga, Craig Virnelson, Uziel Landau, Mark DeGuire, David Zeng ‣ Goals of the ARPA-E METALS Project: – To develop a novel electrowinning process for low-cost extraction of titanium metal from ore, and – Demonstrate stable, energy-efficient extraction of high-purity Ti powder Proposed Electrowinning Cell Design Segmented Diaphragm Design Enables Ti Electrowinning __ + Catholyte Anolyte sponge Proposed Ti C Electrowinning electrolysis Cl2 + TiO2 CO2 + TiCl4 Process Cl2 ! Ti Electrowinning Cl2 Evolution! 2 Technical Concept PROBLEM STATEMENT PROPOSED SOLUTION Use a stack of thin diaphragms e POWER TiCl4 Stack of thin SUPPLY – diaphragms + __ + g l' l' l' n i n +2 n o n Ti i i t A E ΔE w Δϕ u l N o D o r O t v O c D ‘Redox Shuttling’ E H e ΔE l E T e E n A i r C +4 m Ti ΔE o l u Δϕ i h n (LiCl+KCl C a t i eutectic salt T mixture) TiCl4 Ensures diaphragm & cell stability Design Rule: Δϕ = il'/κ < ΔE Increases electrowinning efficiency Problem with diaphragm-less cell: Design Rule: Δϕ = il'/κ < ΔE Redox shuttling of titanium ions causes low current efficiency Ensures diaphragm & cell stability Increases electrowinning efficiency Technical Progress (Phase-I) Molten-salt electrowinning reactor Ti sponge was deposited, was constructed and operated isolated and then characterized 6 100 5 Thin diaphragms enabled 80 4 stable cell voltage at 60 3 industrial plating rates 40 2 n>3 diaphragms provide 1 20 efficient Ti electrowinning Cell Voltage (V) Cell Voltage 0 Process Efficiency Process Efficiency (%) 0 0 100 200 300 400 500 600 0 1 2 3 4 5 Time (min.) Number of Diaphragms (n) Technical Progress (Phase-II) ~100 mg Ti deposits were collected and analyzed for purity using EDS Molten-salt electrowinning reactor Titanium was relocated inside a glove-box for ) % (95%) . t controlled environment studies w ( n o i t i s o p m EDS analysis shows up o C t c to 5 wt.% oxygen u d o r contamination in the P Oxygen electrowon Ti deposits 1 2 3 4 5 (5%) Experiment Number TEA Highlights Metal Ore TiO2 Ti C CO2 Electrolysis TiCl4 Cl2 Cl2 Metric ARPA-E METALS Proposed Technology GOALS (Ti Electrowinning) Cost of Ti Sponge < $4 / kg $4-5 / kg Energy Consumption < 35 kWhr / kg 25-30 kWhr / kg CO2 emissions < 11 kg-CO2 / kg 12-15 kg-CO2 / kg ‣ Cost reduction primarily driven by energy-efficiency and process simplicity (elimination of the sacrificial Mg recycling as needed in conventional Kroll process) Future Goals ‣ Purity improvements: – Currently, oxygen contamination of Ti product is a technology risk. To address this risk, we are designing an efficient vacuum distillation unit to purify the Ti product with the goal of achieving >99% purity. Q2 2016 Basic feasibility of Ti electrowinning demonstrated ) A E T , I s T c i t A y l : a r Immediate focus is on improving Ti purity by lowering n o a Q3-Q4 2016 t , l oxygen contamination via distillation a e r n o n o b s a r l e l p o : t Detailed TEA for Ti powder electrowinning underway – C r Q3-Q4 2016 o p y p will likely pivot process towards powder (vs. sponge) r t u s s d u n i d k n I n i I Seeking additional federal and/or industrial funding for T A 2017 developing a Ti powder production process ( QUESTIONS? 8.