Codelco eyes new technology to clean Chile's high arsenic levels

jueves 12 de mayo de 2016 14:40 GYT

By Fabian Cambero

SANTIAGO May 12 (Reuters) - Chile's Codelco is considering building a $370 million plant that will use new technology to remove arsenic from copper concentrate, creating a cleaner and more saleable product for the world market, a company executive told Reuters on Thursday.

Autoclave technology, already used in the nickel and gold industry, is now being applied in Chile to copper for the first time by Codelco unit EcoMetales, its managing director Ivan Valenzuela said.

The EcoMetales autoclaves use oxygen at high pressure and temperatures to treat concentrate, increasing the proportion of copper and removing arsenic.

As the easier deposits in Chile, the world's biggest copper producer, have become tapped out, miners are turning to rockier, dirtier ore to produce the base metal.

But Codelco needs to make its product acceptable to customers, especially in China, the largest importer of Chile's output. Most smelters will not process concentrates with arsenic levels above 0.5 percent, for health and safety reasons.

It is also facing stricter environmental standards in Chile, where rules on arsenic emissions from smelters are being tightened.

Its newest mine, Ministro Hales, produces ores with high levels of arsenic and uses a roaster to reduce them. Plagued with technical issues at the roaster in its ramp-up in 2014-2015, Codelco was forced to cancel some sales and blend 'dirty' and clean concentrate.

Codelco's multibillion-dollar project to take the century-old Chuquicamata mine underground, which is scheduled to be up and running in the mid-2020s, will also produce high-arsenic ore.   Continuación...