240 likes | 345 Views
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 .
E N D
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
OPEN-PIT MINING UNDERGROUND MINING
JAW CRUSHER CONE CRUSHER BALL MILL
CYANIDE PROCESS
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)
Dissolution of Au 4 Au + 8 NaCN + O2 + 2 H2O → 4 Na[Au(CN)2] + 4 NaOH • 95% to 98% recovery Agitation Leaching lower-cost extraction low-grade deposits Lengthy process (3 mos) 65% to 85% recovery Heap Leaching
ELECTROWINNING AuCN4- + 2e- <--> Au (s) + 4CN- AgCN- + 2e- <--> Ag (s) + 2CN- Half reactions: Au3+ (aq) + 3e- Au (s) Ag+ (aq) + e- Ag (s)