Environmental impacts of small-scale mining Peter W. U. Appel
Environmental impacts of small-scale mining
Peter W. U. Appel
Common physical environmental problems caused by small-scale mining
• Deforestation
• Siltation of drainage system
• Land degradation
Deforestation
Siltation
”Washing” the cloth
Land degradation
Large scale vs small-scale
Health problems
• Dust
• Noise
• Cave in
• Chemical polution –mercury/cyanide
Dust = silicosisNoise = tinnitus
Gold extraction methods
• Gravitative e.g. Mali
• Mercury in modest amounts e.g. Tanzania
• Mercury in escessive amounts e.g. Philippines
• Cyanide e.g. Philippines
Mali – no mercury
Mercury pollution Tanzania vs Philippines
Mercury consumption in gold extraction
• In Tanzania ~ 1gram of mercuryfor 1 gram of gold
• In the Philippines >20 grams of mercury for 1 gram of gold
Tanzania – modest mercury
CrushingMilling
First step in gold extraction
”Washing” the clothSluicing
Amalgamation – last step in gold extraction
Tailings in Tanzania
<0.019.02OT-2C
<0.015.05OT-2B
0.587.51OT-2A
2.215.20OT-1C
2.156.85OT-1B
1.946.67OT-1A
Mercury g/tonGold g/tonSample no.
Mercury pollution Tanzania
Soil sampling
Soil samples Itumbi
0.24SS-6 7 km from Itumbi village
1.1SS-5 3.5 km from Itumbi village
0.76SS-4 In Itumbi village
0.57SS-3 In Itumbi village
0.29SS-2 In Itumbi village
3.54SS-.1 In Itumbi village
Mercury content g/tonSample no. and location
Mercury >0.5 g/ton is considered
dangerous
Soil samples Londoni
2.9SS-15 10 km from Londoni village
0.83SS-14 In Londoni village
0.69SS-13 In Londoni village
0.22SS-12 In Londoni village
0.31SS-11 In Londoni village
0.87SS-10 In Londoni village
0.77SS-9 In Londoni village
0,07SS-8 A km outside Londoni village
0.09SS-7 A km outside Londoni village
Mercury content g/tonSample no. and location
Mercury >0.5 g/ton is considered
dangerous
Lower values in Londoni compared to Itumbi may be because small-scale gold mining in Itumbi has gone on for many years
Philippinesexcessive mercury consumption
Mercury flour
Mercury (+ gold) is lost to the tailings
1101+Luklukan494859
7313+Casalugan494858
12014+Casalugan494857
20014+Sibutad494856
25016+Sibutad494855
Mercury g/ton
Gold g/ton
Aftercyanide
Beforecyanide
LocationSample no
Burning the tailings
How serious is mercury pollution?
Minamata in Japan
27 tons of mercury released over a period of 34 years
Thousands died and many more were crippled
In the Philippines
200 to 500 tons of mercury released every year from small-scale mining
How many will die and how many will be borne crippled?
Health problems caused by mercury
• Tremors
• Difficulty walking
• Tunnel vision
• Psylogical problems
• Cancer
• Death Pregnancies
12 year old Philippine girl severely mentally and physically crippled in pre-natal state by mercury
The mercury whichharmed her stemmed from
small-scale mining
What can be done to reduce mercurypollution?
Introduce recycling of mercury and/orborax gold extraction method
Gold extraction with retort
Borax method
Cyanide gold extraction
Small-scale miners cannever extract all their
gold. Mostly they loosein the order of 40%
Cyanide is a way out
Cleaning of tailings in the Philippines
State Battery
Leisure time in small-scale
miningcommunity
Home made pool for kids