FLOTATION
Floating to the top
Bigger cells, retrofits, reagent news and more: John Chadwick reports
In July, there was major reagent news when Clariant and Huntsman Corp presented a first update on the planned merger of equals.“ The preparations to create HuntsmanClariant, a leading global specialty chemicals company, are showing continued strong progress and are proceeding as planned with an unchanged closing targeted for December 2017 / January 2018.”
Clariant and Huntsman have agreed on a joint strategic direction for near- and long-term value creation based on continued focus on higher growth and higher margin businesses, expansion of existing strong downstream presence, reaping benefits of complementary product portfolios and breadth of reach to deliver an additional organic sales revenue growth of around 2 % per year at about 20 % EBITDA margin and delivering synergies in excess of $ 400 million as well as the $ 25 million tax savings.
“ The merger brings together two strong specialty chemicals businesses with similar EBITDA margins at 17.2 %( including synergies). It will reap complementarity benefits between Performance Products, Care Chemicals and Natural Resources, which represent approximately 35 % of HuntsmanClariant combined sales and hold a comprehensive surfactants portfolio in high-end niche markets globally.
“ It will have meaningful opportunities for growth including cross-selling potential and new product applications. The complementary assets and geographic fit provide significant commercial opportunities and more global reach within established routes to market.
“ HuntsmanClariant’ s position as a leading global specialty chemicals company will further benefit from complementary R & D and technological expertise as well as shared knowledge in sustainability and crossfertilisation in innovation and technology capabilities.”
Clariant Mining Solutions notes the“ decline in ore grades making it difficult for mining companies to increase their productivity levels.” It says it is ready to contribute“ as the only global supplier with end-to-end, value-adding technical solutions, ready to provide its customers with chemicals, service, and technical expertise.”
Clariant has a collaborative technical community of experts around the globe, ready to share knowledge and expertise to solve a multitude of flotation needs. For example, the Clariant Mining team was working with a customer on an ongoing project towards the development of a modifier that lessens the deleterious impact of clay materials in the flotation of sulphide ores. This technology was originally developed as part of Clariant’ s phosphate portfolio, based on a specific application that tackles fine particles issues. In close partnership with the customer, the combined team was quick to identify a solution. Proper value chain analysis and precise description of the technical problem enabled the moving of the project from laboratory development to customer validation in less than two months.
The increasing complexity of orebodies is also a reality for iron ore beneficiation plants. Changes in mineralogy and texture pose challenges and there is a clear need to minimise the iron losses when processing certain orebodies. Clariant dedicated resources to understand this particular technical challenge in its entirety developing an innovative collector for iron ore reverse flotation that can float coarse silica.
Another innovation success was the development of a novel molybdenum collector. Certain copper ores do not respond well to typical petrochemical based collectors – such as diesel, kerosene, or other crude oil fractionation products. There was a clear need for an alternative molybdenum collector that didn’ t impair copper recoveries. To meet this need, Clariant created a new molybdenum collector
portfolio, which delivers superior metallurgical performance and is less hazardous than diesel or kerosene.
It has also improved a copper and molybdenum collector specifically developed for a sizeable Chilean copper and molybdenum mining and smelting operation as that operation began extracting ore from a section of the mine high in pyrite. With iron-to-copper ratios above 2:1 in the ore, the copper concentrate grade dropped from 29-31 % to 24-27 % when using the standard xanthate collector, which reduced production in the smelter and increasied the emission of hazardous gases by the smelting process.
The customer established a target of 30 % for the copper concentrate grade of material sent to the smelting furnaces. In addition, the customer requested the possibility of the collector improving collection of molybdenum. Clariant technical experts worked in collaboration with the customer’ s mine technicians by conducting a series of lab trials. The customer’ s lab results correlated with Clariant’ s findings, and the collector was qualified for full-scale field trials. At the flotation cells, collector dosage rates were adjusted to obtain the correct amount that floated copper / molybdenum and suppressed pyrite flotation without overflows and material loss. Clariant and the customer’ s mine engineers determined that 25 to 30 g / t of ore processed was the proper dosage for this application. A dosage of 8 to 10 g / t of the standard xanthate collector was also employed to avoid higher selectivity and potential drop of copper recovery. Total collector cost increased by only $ 2 million annually while saving the customer $ 30 million in smelting costs, representing a 15-time return on investment.
SuperCell
FLSmidth’ s 660 m ³ SuperCell machine has been constructed and commissioned and is reported by the company to be“ the largest installed and operating flotation machine in the world( by 30 %).” The paper Metallurgical Performance of the 660 m ³ SuperCell™ equipped with the nextSTEP™ Rotor and Stator by B. Dabrowski, D. Lelinski, K. St. John, D. Stevens, M. Walker and A. Weber explains how water testing was completed on three rotor-stator designs and showed excellent correlation to CFD predictions. Once the Dorr-Oliver SuperCell hydrodynamic evaluation was completed, the cell was commissioned with slurry and went into production, which also included further operational tests including solids suspension, metallurgical, power consumption, etc.
During the metallurgical testing of the 660 m ³ SuperCell, it was operating as a rougherscavenger and received an average feed grade
24 International Mining | NOVEMBER 2017