Carajás - Gold Mine

Iron stained mud cracks in the bottom of Mina Igarapé Bahia.

Day 2 took us to the massive Mina Igarapé Bahia gold mine that is cut into the floor of the jungle with minimal disturbance to the jungle beyond the boundaries of the mine.

Our host from the CVRD explained that the mine is now in transition between originally recovering gold from weathered rock and now converting to recovery of primary copper-gold ore veins. He explained the cyanide-leach process to recover the gold. Ore is spread out and sprayed with sodium cyanide solution to dissolve the gold. The concentrate is recovered on coconut charcoal and the cyanide recycled..

We then went to the bottom of the pit where collected manganese (cryptomelane), copper and iron (goethite) minerals. In time, many of us took refuge from the sun while others collected samples for research.

We went to the upper levels of the mine where Paulo explained efforts to date the deeply weathered horizons using rare gasses contained in hydrous iron and manganese oxides.

Our next task was a walk through the jungle with guides from the mining camp.

 

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