Where economics meets sustainability: innovation in flotation

Innovative flotation retrofits and upgrades 

Retrofit of existing installations extends the operational life of legacy equipment. It also simplifies the transition to higher-performance and more sustainable technology by allowing mining operations to modernise processes without extensive capital investment. 

WEMCO II and nextSTEP technologies are both available as retrofit options. WEMCO II technology is compatible with existing WEMCO cells, requiring minimal downtime and providing a rapid return on investment. Meanwhile, the nextSTEP mechanism can be retrofitted to cells of all makes and models. This includes the nextSTEP Retrofit Kit to convert self-aspirated flotation machines to forced-air operation without requiring the replacement of all mechanical components. With low conversion costs of about 70% less than a complete replacement, it is ideal for converting WEMCO installations to mixedROW configurations.  

In addition, FLS offers its froth recovery upgrade package to enable better control of the froth phase. Level sensors feed slurry depth and level data to actuators, which adjust the position of dart valves accordingly to maintain slurry levels in the tank. Meanwhile, radial froth crowders reduce top-of-froth surface area and increase froth movement to the nearest radial launder. This package improves recovery and grade, allows higher throughput at the same performance level, reduces reagent use, and delivers better control of froth level and surface stability.  

The crucial role of flotation in mineral processing 

Flotation has been a cornerstone of modern mineral processing since the early 20th Century. The first patent for froth flotation was granted in 1905 to the Elmore brothers, Francis Edward and Alexander, who used a mixture of oil and air to separate sulphide ores. By the 1920s, froth flotation had become the dominant mineral separation method as larger and more efficient cells replaced earlier gravity-based jigs and shaking tables. Subsequent decades saw the introduction of reagents such as frothers and collectors, allowing improved recovery and selectivity.  

Flotation works by passing air through a mineral slurry via a rotating rotor-stator. This creates bubbles that attach to hydrophilic mineral particles. Bubble-attached particles float to the froth zone at the top of the tank, where they are removed. Non-floated particles are rejected as waste. There are two main types of flotation. A forced-flotation cell uses an external air blower to introduce air into the slurry through a hollow shaft and holes in the rotor. In contrast, in self-aspirating flotation, air is drawn naturally into the slurry under suction created by the rotor’s motion.  

Flotation remains indispensable in mineral processing today. However, traditional flotation systems face limitations, including high energy consumption, suboptimal recovery rates of coarser and finer particles, and throughput constraints. Modern innovations from FLS, such as WEMCO II self-aspirated flotation and nextSTEP forced-air flotation, tackle these issues through optimised equipment designs. At the same time, smart flotation solutions bring the era of digital optimisation to the flotation cell. Such innovations address the industry’s growing need to process increasing ore quantities cost-effectively while reducing environmental impact. 

Flotation on the path to more sustainable mining 

These latest innovations in conventional flotation technology help tackle some of the mining industry's most pressing challenges, including rising energy costs, declining ore grades, and tightening environmental regulations around water management, tailings, and greenhouse gas emissions.  

As mining companies navigate a rapidly changing landscape, advances in conventional flotation technologies – combined with novel developments in the field of coarse particle flotation – offer a crucial pathway to achieving long-term success, capturing how engineering excellence can align economic and sustainability targets to pave the way toward a better future.