Investigation of Affecting Parameters on Heap Leaching Performance and Reducing Acid Consumption of Low Grade Oxide-Sulfide Copper Ore

Mohsen Azmayandeh

doi:10.11648/j.ijmpem.20170204.11

Abstract

Heap leaching method is known as cheap method for copper extraction. Presence of clay and acid consumer waste minerals are the most critical issues because they may bring out the process from economic mode. For reduce acid consumption and increasing copper extraction in heap leaching method, about 3 tons sample was taken randomly from different low grade zones. After homogenization and spelling into small parts, bottle roll tests were carried out to achieve maximum copper recovery and acid consumption in a short time at pH= 1, 1.1 and 1.2. Maximum copper recovery were 60.8, 60.2 and 60.1%, respectively. Also acid consumption were 107.30, 99.90 and 93.23 kg/t of ore, respectively. After diagnostic tests, nine columns with dimension 2m height and 15cm diameter were filled by 0.5, 1 and 1.5 inches ore. Columns were irrigated with 7, 9 and 11 g/l as acid solution concentration at flow rates of 7, 11 and 15 l/m2*h for 63 days. Results showed that there are high correlation between copper and iron recoveries. Copper recovery changed from 25.5% to 58.9% while iron recovery changed from 4.7% to 15.2%. Acid consumption were achieved between 18 to 54 kg per ton of ore. Acid solution concentration and irrigation flow rate are the most important parameters on the copper and iron recoveries. By increasing of leaching period Copper extraction will increase, but acid will be waste more. Copper and iron recoveries were increased with increasing the acid solution concentration and irrigation flow rate but Increasing in amount of acid consumption does not increase copper extraction inevitably. Irrigation flow rate of acid solution has significant effect on acid consumption. With decreasing the ore particle size, both of copper recovery and acid consumption were increased.

Highlights

Sarcheshmeh copper complex is located in 160 kilometers south-west of Kerman and 50 kilometers south of Rafsanjan and the central area of the Zagros Mountains [1]
Approximately 3 tons ore was taken from low grade zones of Sarcheshmeh copper mine for preparing representative sample
To 107.3 kg per ton of ore and maximum copper recovery was their results are presented in Table 5. 60.8% for total copper

Summary

Introduction

Sarcheshmeh copper complex is located in 160 kilometers south-west of Kerman and 50 kilometers south of Rafsanjan and the central area of the Zagros Mountains [1] Copper production at this complex is done by pyro-metallurgy and hydrometallurgy methods [2]. Following decline of highgrade copper reserves and increasing global demand of copper metal caused that hydrometallurgical and heap leaching method has been designed and used. These method, in addition to being less pollution to the environment is included, provides the extraction of copper from low grade oxide and sulfide ores [3].

Methods

Results

Conclusion