How lead ore is mined

Galena is 86.6% lead, yet the rock it sits in usually gives up only about 4%.

stations: 4
things downstream: 95

The short version

Lead ore is a thin prize in a lot of rock. Miners pull galena from veins and lodes, often alongside zinc and silver, and a mill crushes it as fine as 0.1 mm. Churned with water, air and chemicals, the sulfide grains rise in an oily froth that is skimmed and dried. Concentrate reaches the smelter at 40 to 80% lead or more.

Dig veins and lodes

Ore comes from narrow veins and rounded lodes, usually about 60 m down, though big mixed deposits go far deeper. Mount Isa in Australia opens large sections by stoping from sub-levels and backfills the voids with process waste, rock and cement.
Crush it fine

Concentrating mills reduce the rock until the galena comes free of its waste, sometimes to particles under 0.1 mm across.

under 0.1 mm
Float the sulfide grains

Crushed ore is diluted with water and beaten with air in a tank dosed with pine oil or similar chemicals. Sulfide grains rise in an oily froth, and the mostly worthless rock sinks. Alum and lime help the fine particles clump together, and xanthate helps them float.
Dry the concentrate

Froth flows off the tank and is dried for shipping. The dried concentrate can still carry up to 30% sulfur and up to 15% zinc, which the smelter has to remove.

End of the lineLead ore Next it goes into lead, silver.

Worth repeating

In some deposits galena carries up to 0.5% silver, a by-product that far surpasses the lead in revenue.
Galena can be smelted in an ordinary wood fire, which is why humans used lead from the earliest times.
Zinc and silver mines yield nearly 90% of primary lead ore as a side product.