SX-EW technology involves leaching (the process of dissolving useful ingredients with a solution) in atmospheric conditions of copper ore heaps by means of diluted sulphuric acid. Folowing leaching, the pregnant leaching solution is transported via a drainage system to the next stage. In an SX-EW reactor, the first process to take place is solvent extraction, which involves setting and simultaneous purification of the post-leaching solution. Later, the purified solution undergoes copper electrolysis, which results in cathode copper that meets quality and quantity criteria enabling its sale.
SX-EW technology is used at the Carlota mine in the USA.