Hydrometallurgy: Leaching in Heap, Vat, CIL, CIP, Merrill–Crowe, SX Solvent Extraction

It is possible to perform acid brine leaching tests to evaluate the metallurgical response. The key reagents are sulphuric acid and sodium chloride. For example, the acid sulphuric strength can be 5 g/L during the first tests. It is a good idea to perform a second group of ten tests at 10 g/L of sulphuric acid. All of the leaching tests can be carried out with 200 grams of ore ground at 90 µm K80 (or finer) It is important to consider 1000 mL volume solution, which is composed of distilled water, sulphuric acid and NaCl. Iti is possible to evaluate different additions of NaCl (e.g. 200, 300, 500 g/L). Other important variable to evaluate is the temperature (e.g.25, 50, 75, 100oC).

The test can last 72 hours.At the end of the test (72 hours), after the solid-liquid separation, the cake is washed. The pregnant solution and the cake are assayed for Ag, Pb, and Zn. The final pH and free acid are analyzed in the final pregnant solution.

The slurry is checked at 2, 4, 8, 24, 48 and 72 h for pH. Some samples of pregnant solution are collected for free acid, Pb, Zn and Ag analyses