Larry Zanko

Natural Resources Research Institute (NRRI) University of Minnesota Duluth

July 20, 2017

So…I took the following short course at the SME national meeting in Denver in February…

Mine Waste Management, Tailings and Waste Rock: Technologies and Techniques

Mine Waste Management, Tailings and Waste Rock: Technologies and Techniques

“Are we in the mining business, or the waste

management business?”

How do we make the most out of what we mine, including the by-products?

ZERO

ZERO

• Technology roadmaps for producing benign tailings

• New tailings re-mining & repurposing technologies

• Production of benign tailings

West and Central East

Location map

Minnesota’s taconite industry has mined and processed approximately 6 billion tons of

taconite ore to produce nearly 2 billion tons of finished taconite pellets since the 1950s

This means lots of by-product materials

are generated

What does this mean?

Blast Rock: boulder to +6 inch (+15cm) rock created by blasting; used as-is

Coarse Crushed Rock: -6 inch (-15cm) rock that can be further crushed to specification

Coarse Tailings: -3/8 inch (-10mm) processing plant byproduct, ready-made fine aggregate equivalent

Bituminous and PCC Aggregate High Friction Surfacing (HFS) Aggregate Pavement repair/patching products Select Granular Filtration Media Road Base and Sub-base Embankment Fill Seal Coat / Slurry Seal Cement making feed stock

By-products and Use Examples

Bituminous and Concrete Aggregate Chipseal Railroad Ballast Blast Furnace Trim Cement making feed stock Road Base

Armor Stone Rip Rap Landscaping Stone

Dec

reas

ing

Size

These mining-derived materials can represent a significant alternative to

traditional industrial mineral aggregate sources, inside and

outside of Minnesota.

Our view…

Program focus: mineral resource based by-product

recovery and utilization strategies value-added product and

technology development

Geological, physical, mineralogical,

and chemical

Are there environmental and/or “perception” issues that need to be addressed?

find potential beneficial end-uses that make environmental and economic sense at large…

small scales …and small scales

Zircon sand recovery

includes the development of associated intellectual property (IP) and patents

Value-added friction aggregates Pavement repair materials and

technologies Other aggregate uses Coordinated strategies for reducing

transportation costs

Taconite-Enhanced Pavement Repair Rapid-setting Road Repair Microwave

Mesabi friction aggregate for Alaska DOT , Glenn Highway pavement preservation project: July 30, 2014

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QuartziteGraniteLimestoneTraprockLS-2LUCLC-8LC-5

Increasing magnetite content in taconite rock

From: Hopstock and Zanko, 2004

Heating rates of taconite rock and conventional aggregate

Microwave technology takes advantage of the mineralogy of taconite materials

https://theconversation.com/microwave-repairs-might-annihilate-zombie-potholes-once-and-for-all-39160

March 9, 2016 6.13am EST

https://www.dot.state.mn.us/d1/projects/hwy53relocation/

Aggregate use: • Select Granular Borrow (subgrade) plan quantity: 136,000 CY • Aggregate Base Class 6 plan quantity: 69,650 CY

Transportation costs Need to optimize movement logistics with

backhauls tied to other transportation-dependent, large-volume resource projects

Transportation equipment availability Ongoing and higher volume end-user

demand to allow for the use of more cost-effective modes of bulk shipping For example, unit trains, Great Lakes vessels,

barges.

Mesabi RangeHoyt Lakes

Taconite Harbor

Rail Network Great Lakes Shipping

Map Source: U.S. Dept. of Homeland Security, 2015

Transportation economics is key

Map Source: U.S. Dept. of Homeland Security, 2015

Long-term beneficial use of dredged materials taken from the Duluth-Superior Harbor for applications such as mine land and gravel pit restoration and reclamation, marginal land and brownfield site improvement, potential biomass plantation utilization, and highway construction projects.

Harbor Dredging: keeps shipping channels open

Photos courtesy USACE

Erie Pier dredged material storage facility

Lake Superior

Dredged material offload point

The Erie Pier facility is reaching its capacity, so there is a pressing need to find beneficial reuse alternatives.

Iron ore docks

Bulk material handling facility Stockpiled

fines area

Use soil-like sediments for improving productivity of ~50 acres of mining lands and other marginal lands every year. Potentially return by-product aggregate

(crushed rock) materials from mines for local and regional construction projects.

Recycle the sediment on

mining lands and other marginal

lands..

Sediment removed from estuary to

maintain navigation channels

Natural erosional processes within the St. Louis

River Watershed

deposit clean

sediment into St. Louis River

estuary

Clean sediment

goes north

…to make these lands

more productive,

e.g., biomass

“Are we in the mining business, or the waste

management business?”

Project support / collaboration Minnesota Department of Transportation

(MnDOT) / Minnesota Local Road Research Board (LRRB)

Center for Transportation Studies – University of Minnesota (CTS-UM)

Alaska Department of Transportation U.S. Department of Commerce, Economic

Development Administration (EDA) University of Minnesota, Duluth – Natural

Resources Research Institute (UMD-NRRI)

Thank you

Larry Zanko University of Minnesota, Duluth

Natural Resources Research Institute (NRRI) 5013 Miller Trunk Highway

Duluth, MN 55811

218-788-2674 lzanko@d.umn.edu

mailto:lzanko@d.umn.edu

Slide Number 1Slide Number 2Slide Number 3The short course’s “Question of the Day”A potential model?A potential model?The NRRI approachMesabi Iron RangeSlide Number 9Slide Number 10Slide Number 11Slide Number 12Slide Number 13Slide Number 14Focus Area ExamplesValue-added examplesSlide Number 17Slide Number 18Slide Number 19Slide Number 20Other aggregate usesHighway 53 realignment projectCoordinated strategies for reducing transportation costsTransportation, Transportation, TransportationTransportation network is in placeTransportation network is in placeLinked strategy?Slide Number 28Slide Number 29Slide Number 30Slide Number 31Slide Number 32Strategy for reducing transportation costsSlide Number 34Project support / collaborationSlide Number 36