Sponsored by: Bulk Mining Explosives

Development of Coarse Particle Frothers in Response to Larger Grind Sizes

Nasaco International Limited have been producing and formulating chemicals for the froth flotation process for 25 years. During this time we have seen major changes in the technology of how collectors, frothers and modifiers are selected and applied.

Nasaco and its sister company Betachem have invested in QEMSEMs and Mineral Liberation Analysis technology to help our customers identify the causes of mineral processing problems; whether they be in the grinding circuit or the flotation circuit. In previous articles, we have shown that these techniques can be used to improve metallurgy by optimizing grinding, sometimes changing flows around regrind circuits to reduce circulating loads. Sometimes to change collectors or frothers. If you know where misplaced material is, it reduces the complexity of the mineral processing problem, allowing a solution to be more easily found. We are working with concentrator staff to help optimise their processes throughout Europe, Africa and the Pacific

More than half of the country’s coal mines are managed by pro-Russian separatist militia.Credit: DmyTo/Shutterstock.

More than half of the country’s coal mines are managed by pro-Russian separatist militia.

Credit: DmyTo/Shutterstock.

The industry is seeing a tendency to coarser primary grinding prior to flotation, this can either be on purpose, for economic reasons, or an issue of ore hardness or just a desire to increase throughput using existing equipment. Usually this means that there is an increase in the amount of middlings or locked particles, providing part of the middling has exposed value mineral, then it can theoretically be recovered. In response to this Nasaco and Betachem have been developing coarser particle frothers. This development is dynamic, particles become bigger, new raw materials become available and so new frothers are developed.

Nasaco and Betachem have developed a range of coarse particle frothers which have shown good recovery and selectivity in the +200 micron particle size range. Our frother formulations are based on glycols, polyglycols and alcohols.

Frothers selection has always been made more difficult by the problems of scale up from the laboratory to the plant – the difference in mechanical performance of a laboratory flotation machine compared to the plant is probably the main reason for this. We have developed test equipment for frother comparison which allows much better scale up than before. This equipment was developed from studies in foam formation and structure, bubble and particle dispersion. Mainly laboratory studies are carried out but the facility exists for in plant studies where warranted.

The standard range of coarse particle frothers centers around the Nasfroth and Betafroth 300 and 500 ranges of frothers. Specific frothers from within the ranges are designed together with our customers to optimise grade and recovery. The products and their formulations are being use in copper flotation in central Africa, Europe and Peru, in nickel flotation in Africa and Europe as well as coal flotation.

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