Optimising the froth surface area throughout the flotation circuit has a critical impact in the process performance. Launders are an essential part of any flotation cell and with the correct design and orientation for specific application, optimal performance can be achieved. Metso Outotec and Hudbay recently worked together to improve rougher flotation performance at Hudbay’s Constancia site, located in southern Peru.

“One of the challenges our customer was experiencing was the lack of overflow in the last cells of the rougher flotation circuit which needed to be improved. This was directly impacting the copper and molybdenum performance. The solution consisted of upgrading each flotation line with Center Launders in the last three e300 TankCells. Installation of Center Launders took place in two stages: the first set of three Center Launders were installed in rougher Line 1 during June 2019 and the second set of three Center Launders were installed in November 2019. This allowed for metallurgical evaluation regarding copper and molybdenum recovery in Line 1 relative to Line 2.”

The results indicated a weighted recovery increase of 0.70% for copper and 1.40% for molybdenum. The incremental cashflow resulted in a payback period of less than six months. The move overall meant improved operability, stability and process control of the rougher circuit.

Metso Outotec was able to take advantage of planned maintenance shutdowns to retrofit the last three cells of the flotation rows. The installation shortened the froth transport distance and optimised froth surface area through use of the Metso Outotec Center Launders. It was followed by making consistent improvements to optimise the performance of the upgraded cells through sampling, laboratory testing and statistical data.