y
y
y
y
WHAT IS THE SMALL MINE CONCEPT?
BASIS OF STUDY
WHAT ARE THE FEATURES OF THIS
CONCEPT COMPARED TO ECHO BAY’S
ORIGINAL CONCEPT?
WHAT ARE ISSUES RELATED TO
REOPENING THE AJ?
THE AJ MINE
y
y
y
y
y
y
y
y
y
y
y
PRODUCTION RATE
MINING METHOD
TAILING DISPOSAL METHODS
UG TAILING DISPOSAL
UNDERGROUND FACILITIES
SURFACE FACILITIES
NOISE
TRAFFIC
EMPLOYMENT OPPORTUNITIES
FINANCIAL IMPACT ON JUNEAU
WATER QUALITY
WHAT IS THE SMALL MINE
CONCEPT AND THE MAJOR ISSUES?
• ORE PRODUCTION RATE: 3,500 TONS/DAY MINED
• MILLING RATE: 2000 TONS/DAY
• WASTE ROCK PRODUCTION: 2000 TONS/DAY OF
ROCK AVAILABLE FOR SALE OR OTHER SURFACE
USES
• ORE RESOURCE: 12.8 M TONS OF ORE (INCLUDES
DILUTION)
• MINE LIFE: 12.8 YEARS
• REVENUE OUNCES OF GOLD: 782,000 OVER MINE
LIFE
• AVERAGE GRADE OF MINED ORE: 0.074 OUNCES
PER TON
• AVERAGE GRADE OF MILLED ORE: 0.118 OUNCES
PER TON
PRODUCTION RATE
MINING METHOD
THE MINING METHOD ANALYZED IN THE
SMALL MINE ANALYSIS IS “LONG-HOLE OPEN
STOPING.” IT CONSISTS OF RELATIVELY
LARGE STOPES ROUGHLY 150 FT LONG BY
150 FT WIDE BY 200 FT HIGH.
y THIS METHOD IS MORE SELECTIVE THAN
BLOCK CAVING USED BY THE AJ IN THE OLD
DAYS, OR SUB-LEVEL STOPING USED IN THE
LARGE MINE ANALYSIS.
y LONG-HOLE OPEN STOPING WOULD NOT
RESULT IN NEW CAVING
y
y
UNDERGROUND DISPOSAL METHODS
◦
◦
◦
◦
y
DRY TAILINGS
PASTE
PASTE WITH CEMENT
HYDRAULIC BACKFILL
SURFACE DISPOSAL
◦ NOT RECOMMENDED
y
SUBMARINE DISPOSAL
◦ NOT RECOMMENDED
TAILING DISPOSAL METHODS
y
UTILIZE EXISTING UNDERGROUND
OPENINGS
◦ CAPACITY OF DEEP NORTH STOPES: 8.2 M TONS
y
CAPACITY OF NEWLY MINED STOPES
◦ CAPACITY OF NEW STOPES: 7.7 M TONS OVER
PROJECT LIFE
TOTAL CAPACITY OF STOPES: 15.9 M TONS
y REQUIRED CAP. FOR DISPOSAL: 6.1 M
TONS
y CONCLUSION - THERE IS PLENTY OF ROOM
TO DISPOSE OF TAILINGS UNDERGROUND.
y
UNDERGROUND TAILING
DISPOSAL
UNDERGROUND FACILITIES
y
y
y
y
y
y
y
ORE AND ROCK WASTE MOVEMENT WOULD TAKE
PLACE ALONG ROADWAYS, THROUGH ORE
PASSES, AND BY RAIL AND IN MINE HOISTING
FACILITIES
ORE SORTING, GRINDING AND CONCENTRATING
WOULD TAKE PLACE IN THE UNDERGROUND
MILL FACILITY
PROCESSING OF TAILING MATERIAL AND
DISPOSAL WOULD TAKE PLACE UNDERGROUND
WAREHOUSING OF SUPPLIES AND EXPLOSIVES
EQUIPMENT MAINTENANCE SHOPS
WATER TREATMENT FACILITIES
POWER GENERATING
y
y
y
AN ADIT LOCATED NEAR SEA LEVEL –
PREFERABLY BETWEEN THE OLD AJ
STEAM PLANT AND “LITTLE ROCK DUMP”
TO ACCESS THE OREBODY
MINE OFFICE, CHANGE HOUSE,
WAREHOUSE AND ROCK STORAGE
POWER GENERATION (MAY ALL BE
UNDERGROUND)
SURFACE FACILITIES
NOISE
y
y
y
y
y
NOISEY EQUIPMENT SUCH AS SCOOP
TRAMS, TRUCKS AND MAN TRIPS WOULD
RARELY BE OUTSIDE OF THE MINE
CRUSHING AND GRINDING WOULD BE
UNDERGROUND
BLASTING WOULD ALL BE UNDER-GROUND
AFTER INITIAL PORTAL DEVELOPMENT
WASTE ROCK HAULAGE FROM ADIT AND
STOCKPILING OF ROCK ON THE SURFACE
NOISE BARRIERS WOULD BE CONSTRUCTED
ON THE SURFACE AS REQUIRED
y
y
y
TRAFFIC TO AND FROM THE MINE PLANT
SITE WOULD BE LIGHT EXCEPT AT SHIFT
CHANGE
PARKING NEAR THE PLANT SITE IS
EXPECTED TO BE DIFFICULT DEPENDING
ON THE FINAL LOCATION OF THE ADIT
THE MINE OPERATOR SHOULD BE
ENCOURAGED TO PROVIDE BUS
TRANSPORT BETWEEN THE PLANT SITE
AND SATELLITE PARKING AREAS
TRAFFIC
EMPLOYMENT OPPORTUNITIES
MINE/MILL EMPLOYMENT WOULD BE
EXPECTED TO REACH ABOUT 200 DURING
PRODUCTION
y TYPES OF EMPLOYMENT OPPORTUNITIES
INCLUDE: SKILLED AND UNSKILLED LABOR,
MINERS, EQUIPMENT OPERATORS, MILL
OPERATORS, ENGINEERS, GEOLOGISTS,
OFFICE WORKERS, MANAGEMENT STAFF,
CHEMISTS, BIOLOGISTS AND SAFETY
PERSONNEL
y WAGES AND BENEFITS WOULD BE
COMPETITIVE IN THE MINING INDUSTRY
AND SE ALASKA
y
FINANCIAL IMPACT ON JUNEAU
ROYALTIES AND RENT PAID TO THE CBJ
MINING COMPANY WOULD MAINTAIN THE
UNDERGROUND OPENINGS AND WORK
AREAS
y ADDITIONAL SALES TAX PAID BY MINE
EMPLOYEES AND EMPLOYEES OF LOCAL
BUSINESSES
y MINING COMPANY AND EMPLOYEE SUPPORT
OF EXISTING BUSINESSES
y IMPROVEMENT IN THE LOCAL BUSINESS
CLIMATE AND IMPRESSION OF JUNEAU AS A
GOOD PLACE FOR NEW BUSINESSES TO
RELOCATE
y
y
EXISTING MINE DRAINAGE WOULD
CONTINUE TO BE DIRECTED TO THE DRAIN
TUNNEL CONSISTENT WITH REQUIRED
WATER QUALITY STANDARDS
y MINE DRAINAGE FROM ACTIVE WORK AREAS
WOULD BE TREATED AND RELEASED TO THE
DRAINAGE TUNNEL OR USED IN THE
MILLING PROCESS, FOLLOWED BY
TREATMENT AND RELEASE TO AN OUTFALL
IN GASTENEAU CHANNEL
y ALL WATER DISCHARGES WOULD BE
SUBJECT TO NPDES PERMITS
y
WATER QUALITY