The combined acid, scrap and treatment charges for the cement copper
resulted in an operating cost in excess of $300/t of metal; higher than a normal sulphide operation would be.
The liquor was filtered off and treated with copper powder or cement copper
Then, in the 1980s, Leonor was purchased by Minera Cobrenorte Ltda and underground mine development began, together with the construction of a small plant producing cement copper
Ironically, MRI seems to have stumbled upon a marketing niche for its cement copper
precipitate which is now more in demand by many smelters.
The pregnant solution is pumped from there to the cementation tanks where scrap iron is added to obtain cement copper.
Final cement copper grades 60% Cu in the first tank, 55% Cu in the second and 46% Cu in the third.
6) 1988 total, does not include cement copper
precipitates (7) 1988 figure.
operated one copper mine to produce 1,032 t of cement copper
and exported a small quantity of iron pyrites from stock.