NEPA & Mining Tribal Lands and Environment Forum. August 17, 2015 Minneapolis, Minnesota

Transcription

1 NEPA & Mining Tribal Lands and Environment Forum August 17, 2015 Minneapolis, Minnesota Cindi Godsey, Permit Writer and Alaska Mining Coordinator Lynne Hood, NEPA Reviewer David Tomten, RPM and Idaho Mining Coordinator 1

2 Mining Information Session Module 1: Mining Fundamentals Module 2: Environmental Concerns & Issues Module 3: Regulatory Process & How Tribes can Engage Module 4: Lessons Learned 2

3 Module 1 Mining in the US Mining Development Process Mining Fundamentals Exploration Types of mining Types of mineral processing Mining waste products 3

4 U.S. Mining Overview Gold mines in NV, CO, AK, with a new mine under construction in SC (NV most active with around 150) Copper mines in AZ, NM & MI w/new copper/gold mines potential in AK, ID, MN and WI Copper and gold mines comprise 80% of the US facilities Silver mines in AK, AZ, UT & NV plus others 4

5 U.S. Mining Overview (cont.) Lead mining takes place in MO and AK Zinc mining occurs in TN and AK Phosphate mining takes place in FL and ID Iron ore mining occurs in MN and MI Uranium mining is taking place in NM & CO with new exploration elsewhere 5

6 Active Precious Metals Mines 6

7 Uranium Deposits 7

8 Coal Deposits 8

9 Alaskan Large Mine Projects Alaska Facts The Last Frontier Area: 663,300 mi² Streams: 365,000 miles Lowest Point: sea level Highest: 20,320 ft 61.8% is Federal land 9

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11 Major Steps in Mine Development Process Prospecting - Geological data and map reviews, non-invasive exploration Staking - Establish Mining Rights Exploration (includes drilling, geophysics, bulk sampling) Assessment of Mineral Potential and Economic Feasibility Mine development planning, environmental review and permitting process Mine development (Construction) Mine operations Shutdown and reclamation Long term monitoring and site maintenance 11

12 Initial Exploration Advanced Exploration Typical Time Frame for a Successful Mine Project Environmental Studies Prefeasibility Studies Feasibility Studies NEPA & Permitting Financing Construction YEARS 12

13 Mineral Prospecting and Exploration 13

14 Lands Open/Closed to Mining Open: All federal lands not specifically withdrawn from entry under the Mining Law including national forests Closed Lands: Bureau of Reclamation lands Conservation Areas National Monuments and National Parks, National Wildlife Refuges Wild & Scenic Rivers within ¼ mile of bank States tend to follow federal laws 14

15 State & Federal Mining Claims Laws and regulations: 1872 Mining Law State-specific laws Federal Mining Claims require a discovery Claims are self-initiated 15

16 State & Federal Mining Claims Claims are held through rental fees and assessment work: Claims on Federal Land: File notice with BLM; $135/year per claim ( acres) Claims on State Land: State laws vary Royalties: Federal: None required State: laws vary from none up to 10% of net income/year from mining 16

17 Patents Convert federal land to private land Currently there is a moratorium on patenting 17

18 Exploration Activities Geologic Mapping Rock, sediment, and soil geochemical sampling Claims staking Geophysical surveys (air & ground) Trenching Core or Rotary Drilling Bulk sampling Resource estimation Early Stage Mid-Stage Advanced Stage 18

19 Exploration is activity spent searching for mineral deposits Activities generally have little ground disturbance. More expensive with continued success. Permits required for ground disturbing activities. 19

20 Types of Permits for Exploration Federal Permits Potentially Clean Water Act 404 general permit for wetlands disturbance On federal land: approval by USFS and/or BLM State Permits Vary with state Typically land use permit 20

21 Sediment Sampling 21

22 Airborne Geophysics 22

23 Soil Sampling to Explore for Gold 23

24 Core Drilling 24

25 Commodity Prices Commodity prices have a direct effect upon exploration expenditures 25

26 Mining 26

27 What is a mine? Where rocks containing valuable minerals (ore) are extracted from the ground Rates: 100s 100,000s of tons/day Types of mining: Open pit Underground Strip mining Placer mining (gold) 27

28 Open Pit Mining Ore accessed from the surface Blasting Haul to crusher/mill 28

29 Open Pit Mine Fort Knox Mine, AK 29

30 Underground Mining Ore accessed by adit, shaft & tunnel 30

31 Underground Mine Greens Creek Mine, AK 31

32 Strip Mining Reclamation Active Mining Pre-Mining Usibelli Coal, AK Two Bull Ridge Usibelli Coal Mine Healy Alaska Topsoil Replaced/ Revegitation Regrade Backfilling Active Pit Prestripping/ Topsoil removal Direction of Mining Topsoil Regraded Area Over and Inter Burden Coal Seams Spoils 32

33 Strip Mining Southeast Idaho Phosphate Mines 33

34 Gold Placer Mining Oregon Suction Dredge Alaska Mechanical Dredge 34

35 Mineral Processing 35

36 What is mineral processing? Production of valuable metal from mined ore 36

37 How are metals produced from the ore? Separate valuable mineral from waste minerals 37

38 Mineral Processing Steps First Stage - Crushing & grinding Second Stage - Concentration or extraction of valuable mineral (e.g. flotation, leaching, gravity) Third Stage - Metal produced from the mineral (e.g. smelting, refining) 38

39 Mineral Processing Red Dog Mine, AK Bingham Canyon Mine, UT 39 39

40 Crushing & Grinding Reduce particle size to expose mineral surfaces Water is added at this stage. Chemicals may be added 40

41 Flotation Commonly used for many minerals Chemicals added to ground ore cause mineral particles to stick to air bubbles, create a froth, and depress waste minerals e.g., organic compounds (xanthates), cyanide, copper sulfate, zinc sulfate, oils, alcohols, lime, acids 41

42 Flotation 42

43 Leaching Can be used on ground ore or flotation concentrate. Chemical added to dissolve the valuable metal. Examples: Cyanide leaching gold and silver Acid leaching copper, uranium 43

44 Vat & Tank Leaching 44

45 Heap Leaching 45

46 Separation of Metal from Leach Solution Carbon Adsorption: gold adsorbs onto carbon Electrowinning: uses steel wool or copper as a cathode to extract the metal in acid or base solution Precipitation: Solution is combined with chemicals to form metal precipitate 46

47 Production of Metal Smelting and refining 47

48 Example of Gold Mining & Mineral Processing Ore Body Open Pit Mine Waste Rock Ore to waste rock dumps to tailings disposal crushing grinding Flotation Tailings flotation Flotation Concentrate 48

49 Example of Gold Processing Flotation Concentrate autoclave oxidation spent carbon reactivation carbon stripping cyanide leaching carbon adsorption Loaded carbon to tailings disposal leach tailings Stripping solution electrowinning refining Gold 49

50 Questions and Comments 50