Fine Material Spiral Concentrators
Although around 90% of global manganese still goes into steelmaking, demand for battery-grade manganese is projected to grow steadily as EV manufacturing and energy-storage systems expand. This rising dual demand is driving producers to seek beneficiation solutions that reduce fine manganese tailings by producing an additional saleable product from previously discarded material.
A manganese producer in West Africa turned to Multotec to maximise recovery from its -1 mm fine tailings, which had previously been overlooked. Although the client had purchased a Multotec heavy-minerals unit years earlier, it remained idle for nearly three years. Multotec recommissioned and optimised the unit in just four days.
Following this, the unit ran at full capacity, efficiently recovering a 47% high-grade manganese super-concentrate from the 26% manganese in the feed, unlocking significant additional value.
Processing opportunity
Miners traditionally target the attractive lumpy manganese fraction, which is easier to beneficiate and readily saleable into the export market. The finer -1 mm fraction, however, has often been discarded or stockpiled.
Yet during periods of high demand or commodity price volatility, this fine material represents a substantial opportunity to unlock additional value from the resource, particularly because the material has already been mined and crushed, meaning most of the cost has already been absorbed.
By adopting the correct gravity separation technology based on feed properties of the ore, such as particle size, particle shape and feed density, miners can benefit from fine and ultra-fine manganese ore into a saleable product that meets offtake requirements.
Recovery and quality
Spirals remain one of the most efficient and cost-effective methods for beneficiating manganese ore, particularly when dealing with fine, high-density material. Spirals offer a low-energy, low-maintenance solution that can be configured to target both recovery and product quality, making them well suited to the variable ore characteristics common in African manganese deposits.
Menzi Xulu, Senior Process Engineer at Multotec, explains, “Our SC range of spiral concentrators are suited to fine, high-density mineral separation, which is a key requirement in manganese beneficiation. They are typically used in the roughing and scavenging stages, where the focus is on maximizing recovery from the feed. The SC21 spiral is then applied in the cleaning stage to upgrade the manganese and achieve the required product specification.”
Entire orebody
Over and above the SC20 and SC21 fines spirals, an UX7 spiral was developed for the beneficiation of ultra-fine heavy minerals that have traditionally been lost to tailings. The UX7 is efficient in the recovery of ultra fine heavy minerals including manganese roughing and scavenging.
This combination of roughing, scavenging, and cleaning spirals allows producers to recover more manganese from the entire orebody, including fines.
Fit-for-purpose
To recover fine manganese cost-effectively, even during low commodity prices, Multotec deploys its modular and mobile heavy mineral test plants. The system combines several of the company’s technologies.
Wilna Hoffmann, General Manager for Business Development at Multotec say,: “Fitted with Multotec cyclones, spirals, and pumps, the unit can treat 40 tons/hour of fine material in just three stages to produce a saleable manganese product. It is also operator-friendly and designed as a basic but cost-effective solution that can easily be transported and commissioned quickly.”
