Flotation Experiment of Copper

Introduction

Copper (Cu) is a malleable, high conductive metal element. It does not react with water but reacts with oxygen like many metals. In the Earth’s crust, it mostly exists together with zinc (Zn) and lead (Pb). Native copper has many usage areas, even in ancient times. Almost %60 of the copper production is electrical industry purposed. In addition, copper is produced from the sulfide ores in today’s processing plants. In nature, it is found in many forms, such as native, malachite and azurite, bornite, or chalcopyrite, which was processed in this experiment (Wikipedia, 2021). Some of the properties of copper are pointed out below in table.

Note: Adapted from King, H. M. (n.d.-a). Copper Mineral | Uses and Properties

About the Experiment

The experiment isthe 28th experiment but 27th in the official documentation. This experiment consists of two stages for better separation. The first step is bulk flotation, and the second step is selective flotation. The sample is mainly containing chalcopyrite (CuFeS₂), pyrite ( Fe S2), and copper (Cu) itself. The purpose is to gain the copper in the chalcopyrite for a better copper concentration.

Note: Adapted from Wikipedia contributors. (2021b, June 25). Chalcopyrite

Properties of Pyrite

Note: Adapted from Wikipedia contributors. (2021d, August 25). Pyrite

Firstly, bulk flotation is processed. The main reason to float both pyrite and chalcopyrite is to depress the silicates more efficiently for better separation. 998.76 grams sample is ground in the rod mill for 33 minutes as calculated at the speed of 44 rpm. The ground sample is taken to the flotation cell from the mill. In the rougher cell, the main purpose is to keep the efficiency high. To float both pyrite and chalcopyrite, the pH of the pulp kept as natural to wit it is nearly 7.5. At the end of the rougher cell, most of the silicates is depressed, and as tailings, they are taken to filter press for dewatering. Then, they are taken to the furnace for drying. On the other hand, the concentrate of the rougher cell contains chalcopyrite and pyrite. They are subjected to cleaning cells two times. The main reason for the cleaning cell for this experiment is increasing the grade.

Parameters of the Bulk Flotation’s Rougher Cell

Flotation of the Sample In the Rougher Cell As Bulk Flotation

The concentration of the last cleaning cell is subjected to selective flotation. The primary difference from the bulk flotation is increasing the pH to 11.5 because when the pH is 11.5, chalcopyrite starts to float. Hence, pyrite and chalcopyrite separation occurs.

Flotation of the Sample In the Cleaning Cell One As Selective Flotation

The concentrate of the second cleaning of selective flotation is the final concentrate. So, as with all the samples (B-A, B T1-A, B T2-A, S-A, S T1-A, S T2-A, S-K), it is taken to the furnace for drying after the filter press process. The schemes of the flotation circuits are the below figures.