FLOTATION
progressed to pilot testing phase showing superior separation efficiency , providing customers with a solution that allows them to grind coarser , saving energy and water along with offering increased recoveries . Efforts are underway for full scale trials . “ Laboratory testing campaigns have shown that copper can be recovered successfully by recovering coarse particles not recovered by conventional means . Streams as coarse as 600 micron in copper applications have successfully been treated . Recent efforts have shown copper recoveries from a tailings stream in the order of 60-80 % with upgrade ratios as high as 14:1 . With its design based on the RC , the coarseAIR is exhibiting similar advantages in terms of increased throughput per unit cross-sectional area , reduced utility demand and elevated levels of separation efficiency due to the presence of inclined channels in the separator .”
Moving on the more traditional technologies , the FLS WEMCO ® has been the leader of conventional self-aspirated flotation for over 60 years . Ian Coltrin , FLS Product Line Manager Flotation & Attrition told IM : It is well known and well liked . But , as the market suffers from degrading orebodies and increased visibility on the environment , mills around the world have been looking for options that generate more recovery and more control . It ’ s also a great benefit if they can do this with just modifying existing equipment instead of full equipment changeout .”
Coltrin says the WEMCO ® II comes off the heels of the development of the nextSTEP™ forced air flotation machine . This research allowed FLSmidth to streamline the development of the WEMCO ® II by applying similar design elements to increase airflow , suspension , circulation , and attachment . With improved performance FLSmidth was able to add control features for both the airflow and rotor speed to each mill can optimise the performance of their units .
“ Development of the WEMCO ® II has already passed through the bench and pilot scale phase by partnering with a copper mill in North America . Test iterations were conducted side by side with the traditional WEMCO ® unit , supplying FLSmidth with the most reliable data to move forward with . Industrial units have already been installed at mills in both North and South America where FLSmidth has partnered with copper mills to further develop and validate the WEMCO ® II design .”
The WEMCO ® II is fully retrofittable into any existing WEMCO ® design , including round tanks and the 1 + 1 square tanks . In addition , new capital units are also available . Development has already begun on sizes which represent the largest existing install base of WEMCO ® units , with the remaining sizes to be developed in the near future .
DELKOR trials new MAXGen mechanism for BQR flotation cell in India
Plant trials were recently carried out by the DELKOR R & D team , based in Bengaluru , on the lead circuit at the Rampura-Agucha plant , owned and run by Hindustan Zinc Limited ( HZL ) in Rajasthan , India . They tested a new flotation mechanism that has been developed for the BQR flotation cells using 3D print prototype models with bench and pilot scale studies . As outlined in a recent paper , the mechanism shows good flotation kinetics , fine bubble size distribution , and lower power consumption to improve the grade recovery of the product stream . The tests involved a pilot 5 m 3 flotation cell with the MAXGen mechanism at the cleaner-3 position ; and showed even at this small scale its potential to increase both grade and recovery of the plant and simultaneously reduce the energy consumption . The work was published this year in the respected Indian journal , ‘ Transactions of the Indian Institute of Metals .’ Sales Manager - Europe for DELKOR , Rajiv Krishnamurthy additionally told IM : “ Following an excellent initial reaction to BQR MAXGen flotation cells , in the last year , DELKOR continues to gain orders from both new and existing clients for a variety of applications , including nickel , platinum , and gold minerals from various parts of the world . The flotation cell sizes ranged from 20 m 3 to 100 m 3 .”
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
International Mining | OCTOBER 2023