Fine Cassiterite Recovery: MFA Agglomeration Technology for Tin Producers

MFA Technology Offers New Route to Recover Fine Cassiterite in Tin Processing

Tin producers are increasingly looking at ways to recover value from fine cassiterite particles that are difficult to process, according to a report published on 2026-08-10 by the International Tin Association. The source highlights a technology called Mine Fines Agglomeration (MFA), which is being supported for commercialisation by Green Tree Group.

Tin ore must be crushed and ground to liberate cassiterite before recovery, typically through gravity separation. While this works well for coarse particles, it generates large amounts of very fine cassiterite. As particle size decreases, gravity separation becomes less efficient, causing valuable cassiterite to end up in slimes, tailings, and waste streams. These fine fractions can still hold economically significant tin, but recovering them remains technically challenging.

MFA binds suitable fine mineral particles into durable, water-resistant agglomerates using a low-energy, low-temperature process. The resulting agglomerates retain the original mineral composition while improving physical handling characteristics. Unlike conventional methods that often require high-temperature treatment, this process operates under mild conditions and can accommodate a wide range of particle sizes, including fine materials, dusts, and slimes. The company is targeting industrial throughputs above 1,000 tonnes per day per modular unit, though the technology is currently progressing towards pilot-scale demonstration.

MFA is not intended to replace existing beneficiation processes but to complement them by adding a processing stage for fine mineral streams once recoverable material has been identified. For the tin industry, the main opportunity is converting fine cassiterite that might otherwise remain underutilised into a material better suited for handling, storage, transportation, and downstream processing or metallurgical evaluation.

If demonstrated at commercial scale, agglomeration could offer several advantages. Recovering additional cassiterite from historical tailings, slimes, and fine processing streams could increase overall metal recovery without additional mining, aligning with industry efforts to improve resource efficiency and reduce waste. Producing a more consistent agglomerated feedstock could simplify handling, storage, and transport, and where fine concentrates are destined for smelting, agglomeration could provide a more uniform feed while reducing dust generation.

The technology is currently estimated at Technology Readiness Level (TRL) 4-5, and further technical validation will be required as it advances. Green Tree Group is seeking industry partners to support its progression through the UK Government's Critical Minerals Accelerator programme, with the goal of independent optimisation and validation.

As ore grades decline, producers are looking to extract more value from every tonne processed. Agglomeration is one of several approaches being explored, alongside advances in fine-particle gravity separation, flotation, sensor-based sorting, and alternative beneficiation technologies. These innovations could reduce losses throughout the mineral processing flowsheet, supporting more resource-efficient and sustainable tin production.

Green Tree Group is currently seeking collaboration with mining companies, mineral processors, universities, and critical minerals organisations to validate the technology across various critical mineral applications and support its path to commercial deployment.