FLOTATION
largest existing install base of WEMCO ® units , with the remaining sizes to be developed in the near future .
HydroFloat reaching new highs
Eriez Flotation said in May 2023 said that it had won a contract to supply its HydroFloat technology to OZ Minerals ’ ( now BHP ’ s ) Carrapateena coppergold project in South Australia . The project ’ s goal is to increase the recovery of copper and gold from the ore through a more efficient and sustainable extraction process , Eriez says .
HydroFloat recovers particles two times coarser than conventional flotation cells , which allows for a shift in the economic optimum grind size , and in turn increases profitability and improves environmental sustainability of mining projects . In Tailings Scavenger ( TS ) applications , the HydroFloat provides selective recovery of semi-liberated and fully-liberated minerals contained within the coarse size fraction of rougher flotation tailings , thus increasing global recovery . In Coarse Gangue Recovery ( CGR ) applications , as in the Carrapateena case , the HydroFloat is installed in the grinding circuit . Here , the coarse size fraction of the secondary classification process ( U / F ) is fed to the HydroFloat . The tailings produced from the HydroFloat are final tailings , and this allows you to remove approximately 30 % to 40 % wt / wt of the total gangue at coarse fractions (+ 400 μm ) and in early stages of the process .
The Coalition for Minerals Efficiency ( CEEC ) recently awarded the 2022 CEEC Medal for Operations to a group of researchers for their paper on the commissioning of an Eriez HydroFloat ® Separator at El Soldado . The writers of the paper ; Karina Arburo , Jaime Zuniga ; Adrian McDonald and Felipe Valdes , all of Anglo American , along with Jose Concha from Eriez and Eric Wasmund , the Eriez Global Flotation VP , published their research in the proceedings of the Copper 2022 Conference , which took place in November 2022 in Santiago .
Their paper , ‘ Commissioning a HydroFloat ® in a Copper Concentrator Application ,’ describes the successful installation and operation of a HydroFloat in a copper concentrator circuit in a gangue rejection capacity . The HydroFloat technology separates particles based on their hydrophobicity and buoyancy , resulting in a more efficient and eco-friendly extraction process .
Specifically the paper describes how it was applied in an early gangue rejection mode at Anglo ’ s El Soldado operation in Chile , South America . The plant was commissioned in Q1-Q3 of 2021 .
The El Soldado HydroFloat has the capacity to process approximately 30 % of that mine ’ s tailings . The new Anglo American Quellaveco HydroFloat plant in Peru is ten times larger , with ten HydroFloat modules making it the largest CPF in the world . Anglo American stated in June 2023 that it was 70 % complete and expected testing to finish by September 2023 .
At the 11th International Flotation Conference organised by MEI and being held in Cape Town , South Africa , November 6-9 , the application of HydroFloat in iron ore will be presented in a paper titled : ‘ The use of HydroFloat™ Coarse Particle Flotation in Quebec Iron Ore ’ s Bloom Lake Low Silica Upgrade Circuit .’ The lead presenters are Andrew Hobert , Eriez Flotation Senior Manager – Global Business Development and Francois Lavoie , VP Sales , Technical Marketing , and Product Development at Quebec Iron Ore along with BBA ’ s Catherine Pelletier , Process Engineer – Operations plus Erich Dohm , Eriez Flotation Senior Manager – USA Operations .
Blast furnaces and the Basic Oxygen Furnace process is traditionally used to convert a wide range of iron ore oxides into liquid iron in the steelmaking process . This process , which relies upon the use of coke as an energy source , and a reducing agent , generates large volumes of CO 2 emissions . Conversely , electric arc furnaces ( EAF ) produce steel from scrap metal and Direct Reduced Iron ( DRI ) while generating up to 85 % less carbon dioxide than blast furnaces . However , the less CO 2 intensive DRI / EAF process requires a feedstock with very low levels of gangue , typically less than 3 % combined SiO 2 and Al2O 3 .
With recent announcements from various steelmakers to convert their steel production
BGRIMM large cells in the new energy mineral industry
The rapid deployment of new energy technologies as part of energy transitions implies a significant increase in demand for minerals . The types of mineral resources used vary by technology . Lithium , nickel , cobalt , manganese and graphite are crucial to battery performance , longevity and energy density . Especially , the requirement for lithium and graphite is growing sharply .
Flotation is one of the main processes to recover these minerals from their ores .
Xuesai Fan at Chinese flotation technology leader BGRIMM told IM : “ Different from bulk non-ferrous metals , such as copper , molybdenum , lead , zinc , it requires more consideration of coarse solid suspension and floating , and the large mass pull of froth for lithium and graphite flotation . Owing to these characteristics and several years of depressed prices of these materials , conventional large flotation cells can ’ t meet their requirements for processing .” He says in these flotation plants , smaller flotation cells are preferred and chosen in China . BGRIMM has devoted a lot of resources to studying and developing distinctive technology to improve the flotation performance of the large cells for these new energy minerals .
Fan comments : “ Yichun district , in Jiangxi province , is rich in lithium , that mainly exists in lepidolite . The total amount of lithium oxide resources is about 9 Mt , and the grade of lithium oxide is mostly about 0.2-0.6 %, equivalent to about 22 Mt of lithium carbonate . The capacity of the flotation plants is less than 2,000 t / d , and the largest size of flotation cell is 4 m ³. With the price of lithium carbonate increasing sharply , the lithium battery company enterprises CATL , GOTION and others have entered into the mining industry . For example , a world-class lepidolite mine has been invested in and is being completed by CATL , of which the annual capacity is 3.3 Mt .” Fan says that for flotation process , there are two parallel lines of BGRIMM cells , including 15 sets of HIF-320 m 3 flotation cells in each line . Since the particle size of the feed is -0.3 mm ( - 74 microns approximately 35 %), the technology in these HIF flotation cells has elevated the position of the rotor and shortened the distance between the rotor and lip , to decrease the particle-bubble attachment transportation distance . “ The froth of lepidolite flotation is viscid and has poor flowability . For enhancing froth recovery , a rotated scraper assembly was developed for these 320 m3 flotation cells . Now , one line is in operation , and the flotation performance has met expectation .”
Moving on to graphite , its demand has grown 25 times from 140,000 t in 2020 to over 3,500,000 t in 2040 ( IEA , International Energy Agency ). The graphite production of China accounts for more than 60 % of the world . Hegang , in Heilongjiang province , has abundant graphite resources . “ The known ore reserves reached 1.731 billion tons , mainly crystalline graphite . 80 % of natural graphite anode materials of the new energy power batteries , and the natural graphite used by battery companies , such as Betray , Samsung , LG , etc , come from Hegang . And these battery companies are suppliers of Tesla , Toyota , BYD and other automobile companies .” In sharp contrast , the flotation plants until now have been mostly small scale in Luobei . Due to poor coarse particles recovery and strong hydrophobicity and drainage ability of graphite froth , the maximum size of the cells was 40 m 3 . “ With the BGRIMM technology of flotation cell development , 16 sets of 100 m 3 forced-air HIF / KYF combination flotation cells have been applied at a China Minmetals Project in Luobei , with a processing capacity of 7,500 t / d . The particle size of feeding is -0.074 mm , accounting for 40 %. The graphite recovery rate is 85 % and the grade is 95 %, and more than 11 % of + 0.15 mm particles in the concentrate .”
36 International Mining | OCTOBER 2023