MINERAL DEPOSITS HOW, WHERE, WHEN, AND WHY HERE

Jim Miller, University of Minnesota Duluth

MINERAL DEPOSIT IQ TEST

1) What is the main use for Nickel?

Stainless Steel

MINERAL DEPOSIT IQ TEST

2) What is the main use quartz (silica) sand?

Glass-making

MINERAL DEPOSIT IQ TEST

3) What is the main use for palladium?

Catalytic Converters

MINERAL DEPOSIT IQ TEST

4) What country is referred to as the “Jewelbox of the World”?

South Africa

MINERAL DEPOSIT IQ TEST

5) What is the principal commodity needed to make Rayon, Polyester and other synthetic fabrics?

Petroleum

MINERAL DEPOSIT IQ TEST

6) What is the only thing in this room that is not grown on or mined from the Earth?

Sunlight

MINERAL DEPOSIT IQ TEST

7) How much copper is in a medium-sized wind turbine? A) 15,000 lbs B) 9,000 lbs C) 6,500 lbs D) 2,000 lbs E) 400 lbs

MINERAL DEPOSIT IQ TEST

8) Chile produces the most (1/3rd) of the world’s copper; which country is the second largest producer of copper at 8%?

United States

MINERAL DEPOSIT IQ TEST

9) What is the average percentage of platinum in the Merensky Reef deposit of South Africa ? A) 10% B) 1% C) 0.1% D) 0.01% E) 0.0001%

MINERAL DEPOSIT IQ TEST

10) What percentage of mineral deposit prospects become mines? A) 50% B) 10% C) 5% D) 1% E) 0.1%

Terminology and Definitions

Biological Resources• renewable• recycleable• reuseable

Mineral Resources• non-renewable• recycleable• reuseable

Water Resources• unlimited• recycleable• reuseable

Wind and Solar• unlimited

“Sustainable Development is development that meets the needs of the present without compromising the ability of future

generations to meet their own needs” (1984, United Nations Commission)

Stewardship - “administration, management, control, including responsible use of resources” (Oxford English Dictionary Online)

Natural Resources – materials, and energy that occur naturally within the Earth’s spheres. Many are essential for our survival, while others are used for

satisfying our wants.

Stuff

Mineral Deposit TerminologyOre – rock whose value of metals exceeds the cost of extracting

them by mining and processingGrade – percentage of a particular metal in ore rockProspect – a mineral occurrence that preliminary investigations

indicate a possibility of a significant resourceResource – tonnage of ore in such form, quality and quantity that

there are reasonable prospects for eventual economic extractionInferred Resource is that part of a mineral resource for which tonnage, grade and mineral content can be estimated with a low level of confidence.

Indicated Resources are economic mineral occurrences that have been sampled to a point where reasonably confident estimate can be made of their contained metal, grade, tonnage, shape and physical characteristics

Reserves - are resources known to be economically feasible for extraction.

How? Most rocks on earth contain some amount of metals, but

metal concentrations are so low (parts per billion - ppb), as to not be considered ORE.

Ore deposits form in under special geological circumstances and processes whereby metals are concentrated to economic grades.

Economic concentrations of metals are created by primary processes (those related to the rock in which they occur) and secondary processes (those unrelated to the origin of the host rock).

In most ore deposits, sulfur &/or oxygen are the main anions (-charged ions) that concentrate metal cations; other metal-bonding anions include As, Bi, Te, CO3, Cl, …

How?

ChalcopyriteCuFeS2 Bornite

Cu5FeS4

CobaltiteCoAsS

SphaleriteZnS

GalenaPbS

ChalcociteCu2S

MolybdeniteMoS2

Pentlandite(Fe,Ni)9S8

CinnabarHgS

How?Most Base Metals are concentrated by Sulfur

HOW?Formation of PGE deposits by sulfide liquation

HOW?Sulfur Contamination creating the Cu-Ni-PGE Sulfide

Deposits of the Duluth ComplexS

Cu Ni Co Pd + Pt + Au

S

HOW?New Processing Technology for Sulfide Ores

OLD – Smelting/Roasting

NEW – Hydrometallurgy with High Pressure Autoclaves

HOW?The Challenge – Acid Rock Drainage

2FeS2(s) + 7O2(g) + 2H2O(l) →

2Fe2+(aq) + 4SO42-(aq) + 4H+(aq)

Where?

Buried too Deep

Just Buried

Where/When?

When?Archean Komatiite Flows with Ni-sulfide

MineralizationEvidence of an Early Hot Mantle

Inconvenient Truth #3When?

Archean Paleo-placer U deposits

Evidence of an Anoxic Atmosphere

Inconvenient Truth #3When?

Porphyry Cu Depositspreserved in young mountain

belts

Peat

Anthracite

Bituminous Coal

AnthraciteCoal

When?Land plants take root on land about 350 Ma COAL!

Inconvenient Truth #3When?

Porphyry Cu Depositspreserved in young mountain

belts

gone

Inconvenient Truth #3Why Here?

Inconvenient Truth #3Why Here?

BECAUSE MOTHER EARTH SAID SO!

Why Here?

Mineral Resource Information US Geological Survey Commodity Information

http://minerals.usgs.gov/minerals/pubs/commodity/ US Geological Survey Mineral Resource Database

http://mrdata.usgs.gov/mrds/ Minerals Education Coalition

http://www.mineralseducationcoalition.org/ Society of Mining, Metallurgy and Exploration (SME)

http://www.smenet.org/ Prospectors and Developers Association of Canada

(PDAC) – Mining Matters Educational Initiativehttp://www.pdac.ca/mining-matters

Lesson Plan Ideas for Mineral DepositsHow to make a lightbulb?

Objective: An important element in promoting stewardship of our earth resources is to educate students about what earth resources are involved in the making of everyday things. We will use manufacturing of a lightbulb to illustrate this point. Exercise: You are an environmentally conscientious entrepreneur who want to build a compact fluorescent lightbulb factory in Minnesota. One of the most important decisions is to figure out what materials you need and where to get them. Cost is a function of distance and the country supplying the material. Third world countries provide cheaper prices, but are notorious for poor environmental standards in mining and low wages. Procedure: You will be assigned an earth resource that is needed to manufacture a CFL light bulb. Using the USGS and MII websites, research the following information on your assigned resource. Geologic occurrence (host rock, geological environment) Enrichment process (primary or secondary?) Age of occurrence Imports (% of US consumption)• Alternative Materials • Other interesting Information