Patricia Panganiban, Ryan Santiago, and Kristina Yatco
proudly present
The Disappearing
Copper Cauldrons
DISCLAIMER: This story is, in fact, not about copper but about gold.Glittering gold.
LONG, LONG AGO in a magical school not found in Scotland where students rode not on magical broomsticks but on NASA-certified rocket ships
were three pretty okay, not so bad students...
GOLD• Dense, soft, shiny, malleable,
and ductile• One of the lease reactive
chemical elements under solid conditions
• Occurs in free elemental form as nuggets or grains in rocks
• World Consumption of Gold: 50% jewelry 40% in investments 10% industry
GOLD INDUSTRY IN THE PHILIPPINES• Gold deposits occur in 73
provinces in the Philippines• Principal producing districts:
Baguio, Masbate, Surigao, and Masara
• Gold Production: 31,120 KGS (2011) (Est Value: PhP 63M)
• Price: Php 2,147.99 per gram
Silver
• Soft, white, lustrous, ductile, malleable (slightly higher than gold)
• Highest conductivity of any element and highest thermal conductivity of any metal
• Occurs in free elemental form, as an alloy with gold or other metals, and in minerals such as argentite and chloragyrite.
Silver• Uses: jewelry, tableware,
utensils, currency, conductors, mirrors, photographic films (compounds)
• Silver Production: 45,530 KGS (2011) (Est Value: PhP 2M)
• Price: Php 45.16 per gram
UNDERGROUND MINING
OPEN-PIT MINING
JAW CRUSHER
CONE CRUSHER
BALL MILL
CYANIDEPROCESS
ROASTING / METAL OXIDE SMELTING
2 AgS(s) + 3 O2(g) + (heat) → 2 AgO(s) + 2 SO2(g)
2 AuS(s) + 3 O2(g) + (heat) → 2 AuO(s) + 2 SO2(g)
Agitation Leaching
Heap Leaching
95% to 98% recovery
lower-cost extraction low-grade depositsLengthy process (3 mos)65% to 85% recovery
Dissolution of Au 4 Au + 8 NaCN + O2 + 2 H2O → 4 Na[Au(CN)2] + 4 NaOH
ELECTROWINNING
AuCN4- + 2e- <--> Au (s) + 4CN-
AgCN- + 2e- <--> Ag (s) + 2CN-
Half reactions:Au3+ (aq) + 3e- Au (s)Ag+ (aq) + e- Ag (s)
TRANSMUTE!
Fin