Among the features included in FLSmidth’s Froth Recovery Upgrade package are radial froth crowders designed for greater flexibility and control. According to the company, they reduce top-of-froth surface area and increase froth movement to the nearest radial launder, allowing for either deeper froth or faster froth removal.

FLSmidth (FLS) has introduced two products that the company claims will significantly advance flotation recovery, the mixedROW flotation system and a new Froth Recovery Upgrade package.

FLS said the two new products aim to help customers meet the twin challenges of a need for better metal recovery while making the flotation process more energy efficient overall. The mixedROW system combines two machines — nextSTEP forced air and WEMCO self-aspirating technologies — and provides boosted productivity, a reduced environmental footprint, and higher profits, according to the company, which describes the system as the first-of-its-kind because it concurrently exploits the characteristics of two separate technologies. When nextSTEP machines are placed at the beginning of a row, they can recover coarse material using the least amount of energy possible, said FLS, and this positioning enables mixedROW machines to lower energy consumption by between 15%-40% while increasing recovery by up to 5%.

In the mixedROW system, WEMCO machines are placed at the end of a row, which increases both coarse and fine particle recovery as they are capable of treating a wide range of particle sizes, said FLS. The elevated rotor position within the machine also reduces energy consumption because the froth only has a short distance to travel. The company claims the mixedROW machines have the lowest head loss on the market, using an engineered system of dart valves that allow efficient transfer of slurry from one tank to another without significant losses.

Pointing out that flotation losses now commonly reach 50% and sometimes go as high as 90% for coarse particles, FLS said it also has worked to develop a product that allows customers to have more control over the froth recovery process. The resultant Froth Recovery Upgrade package offers a range of equipment engineered to improve the productivity of froth recovery, while minimizing the losses of valuable particles, according to the company, which claims the package finds solutions to flaws found in original froth-recovery technology.

Major features of the package include:
• Actuators that control the position of the improved dart valves inside the flotation cells.
• Level sensors with no moving parts, that can accurately measure slurry levels.
• Radial froth crowders designed for greater flexibility and control. These are used to reduce top-of-froth surface area and to increase froth movement to the nearest radial launder, allowing for either deeper froth or faster froth removal.

The result of these improvements, said FLS, is quicker reactions to flow and slurry density changes, thus boosting flotation machine performance. According to the company, the Froth Recovery Upgrade package will deliver better recovery at the same grade or increased grade at the same recovery.