extracting metals from mine waste

Extracting metals from mine waste Three cases of Ni and Cu Tailings and Waste Rock

in Norway INGAR F. WALDER, MARGARET TINSLEY, ASHLYNNE

WINTON, AND RODRIGO EMBILE, JR. Kjeøy Research & Education Center, Norway

New Mexico Tech,

NM Tech – 27th-28th of March 2018

OUTLINE

• LOCATION - BACKGROUND - SETTING • PURPOSE OF THE STUDY • METHODS • TESTS RESULTS • EXTRACTION POTENTIAL

Tellnes deposit – Titania Mine • Ilmenite-norite in an anorthosite complex • Ilmenite extraction; Sulfide extraction biprod. • Pentlandite, millerite, pyrrhotite, chalcopyrite • 2 Mt/year tailings deposition (so far 30 years) • 200-250 ppm Ni conc. in tailings

Råna Layered Mafic Intrusive • Dunite – pyroxenite –norite • Massive to simi-massive ore bodies • Associated with the dunite layers • Pyrrhotite-pentlandite- chalcopyrite-

pyrite • Tailings 7-8 Mton; 200-300 ppm Ni • Waste rocks approx 0.5 Mton

Sulitjelma VMS Deposits • 20 dep.+ within an offiolite complex • Associated with greenstone layer • Cpy – Sph - Gal. in pyrite matix • Tailings 10-15 Mton • Waste rocks approx. unkn. amount

Kjeøy Research & Education Center

PURPOSE

• Drainage water issues and geochemical processes within the waste material

• Leaching potential through column studies for metal extraction

• Practical research projects for Bachelor (2), Master (2) and PhD (1) students

TELLNESVATNET

Water

WET TAILINGS

Tellnes Deposit Tailings Map

0.5 km

DRY TAILIINGS

Seepage

SEEPAGE WATER Tailings dam

SEEPAGE WATER Tailings dam

kg/day

ANALYSIS

• Mineralogy (XRD-SEM) • ABA (acid–base accounting) • SCE (sequential chemical extraction) • Water analysis • Leach tests

• Humidity cell tests 3-7 months • Column Leach tests 2 months and going

Column leach tests

• 6 kg sample • 1L leach solution/week • 7 months duration • Weekly analysis • Acidic process water • Deionized water

• 6 kg sample • 0.5 L/day leachate • +2 months duration • Analysis 1-3 days • Acidic process water • Sulphuric acid

Humid air pump

Leachate

2-3kg of Sample

Column leach tests weekly rinse

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0 50 100 150 200 250Time (days)

pH

"C16-Acid""C17-Norm"

HCT- acid column

Days

ACID ACID WATER

Leach columns

0.01.02.03.04.05.06.07.08.09.0

0 10 20 30 40 50 60 70

pH

Time (days)

pH

Sulfuric Acid

Process water

0

5

10

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35

0 10 20 30 40 50 60 70

Ni m

g/l

Time (days)

Nickel

Sulfuric Acid

Process water

Ashlynne Winton, BS Earth and Environmental Dept.

Leach columns

0.01.02.03.04.05.06.07.08.09.0

0 10 20 30 40 50 60 70

pH

Time (days)

pH

Sulfuric Acid

Process water

0

5

10

15

20

25

30

35

0 10 20 30 40 50 60 70

Ni m

g/l

Time (days)

Nickel

Sulfuric Acid

Process water

Ashlynne Winton, BS Earth and Environmental Dept.

Leach Columns

0

5

10

15

20

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40

0 10 20 30 40 50 60 70

mg/

kg

Days

Nickel Extraction

Waste Water

Sulfuric Acid

SULITJELMA TAILINGS and WASTE ROCKS

Allice Clark, BS Earth and Environmental Dept.

pH – kinetic tests Waste rocks, Sulitjelma

Franciszka Stopa MS Mineral Engineering Dept.

Copper – kinetic tests Waste rocks, Sulitjelma

Franciszka Stopa MS Mineral Engineering Dept.

Potential for Nickel Leaching from the Bruvann Nickel-Olivine Deposit,

Northern Norway

Acid and Alkaline Leach Columns Weakly Column leach tests • 1 L/week • 3-5 kg sample old waste rocks • 35 weeks

Continuous flow columns • Leachate collected continuously,

sampled in batches • about 5 kg sample • Leachate

– Leached with water (weekly), – pH 2.0 H2SO4, – pH 1.5 H2SO4, – either water or pH 12 NaOH.

Margaret Tinsley, MS Earth and Environmental Dept.

Weakly DI water Columns

• Nickel has a smooth decline, remains at mg/L levels for months

• Moderately acidic

Margaret Tinsley, MS Earth and Environmental Dept.

Water Acid Water Leach Results

• Long lasting neutralizing capability

• Lower pH temporarily increases leaching

• Returning to water leach yields a spike in nickel concentration, then a sharp drop.

Margaret Tinsley, MS Earth and Environmental Dept.

CONCLUSIONS • Standard leaching methods feasible for Ni extraction

• Tellnes tailings as well as Råna waste rocks • Olivine content reduces the acid leachability by

effectively consuming hydrogen ions • Approx. 0.2 wt. Cu leached from waste rocks and

tailings at Sulitjelma. over two years, • Nickel extraction is feasible using the acidic process

water • Low pH increase the release of Nickel, but is not

effecting the mobility. • To get cobalt, and copper from the same ore require

a low pH solution.

Further Student Research

Reno Cell www.efftech.co.uk

Active leaching copper of Mine Waste from Sulitjelma • Mineralogy work • Vat leaching, high oxygen flow Olivine leaching to improve Ni recovery • HVEP (patent pending) • Alkaline leach Vanadium extraction EU funded • Magnetite reaction rates • Preheating before leaching Extraction of metals from solution • Solvent extraction electro winning • Ion exchange

Thank you

Any Questions

ingar.walder@nmt.edu funded by

KJEØY RESEARCH & EDUCATION CENTER, New Mexico Tech,

and Norwegian Science Foundation

Weekly rinse - columns

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0.01

0.10

1.00

10.00

100.00

1000.00

0 50 100 150 200 250

pH

mg/

l

Tid (dager)

Tailings Leach, Fe

Acid - Fe Norm - Fe Acid - pH

THANK YOU

QUESTIONS

IWALDER@EES.NMT.EDU

HCT – SCE (Dold, 2003)

0

50

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1 2 3 4 5 6 7 8

Cons

. (pp

m)

"Norm Top" "Norm Bot." Acid Top Acid Bot.

Step

NICKEL total 260 ppm

Water NH4- Acetate NH4-oxalate NH4-Oxalate

H2O2 KCl+HCl+HNO3

Four acid dig.