COMMINUTION AND CRUSHING jaw crushers ( primary ) and cone crushers ( tertiary ) through automation and mechatronics , according to Bradner .
“ Our Synertrex ® IIoT platform and technology was recently used to commission one of our cone crushers for a Latin American customer ,” he said . “ Our technical team based in Wisconsin oversaw the commissioning and were able to manipulate the machine from thousands of kilometres away .
“ Being able to ‘ connect ’ means we can keep the machines running in the best possible condition .”
Drescher says all of thyssenkrupp ’ s primary gyratory crushers are equipped with a basic digitalisation package allowing for optimisation of the crusher operation through identifying anomalies and recognising debottlenecking and throughput opportunities .
“ With the ‘ Reporting & Consulting ’ digital service , the customer receives weekly reports with expert recommendations for the operation and troubleshooting of the crusher ,” he said . “ In case of critical deviations from normal operating behaviour , the customer will be contacted via phone and email .”
The analysis of such data has led to damage prevention ( bushing , gearbox ) for several customers , Drescher says .
Such processing data can also be passed down to other machines in the flowsheet , enabling the whole comminution process to be optimised , he added . thyssenkrupp ’ s digitalisation efforts in the milling process – specifically its HPGRs – goes one step further .
Digital data transfer to an off-site competence centre , for instance , allows the continuous review of HPGR operation in terms of capacity , energy and wear , but also controls and mechanical functionality , Juergen Remmers , Head of Grinding Technologies at thyssenkrupp Mining Technologies , said . Early warnings and regular recommendations can also be provided to operators .
The new AMPS condition monitoring system helps here , detecting critical operating conditions of HPGRs and making recommendations for operators to act on .
“ The AMPS allows operation closer to the machine design limits without damaging the
HPGR , thus , improving production and availability ,” Remmers said . “ The next level of process automation currently under development for our HPGRs is an AMCS , which enables automated process optimisation to maximise production .”
Malone and Hoerschkes said the ongoing development of its primary gyratory crushers , in terms of increased power and capacity , had shifted the emphasis to fully leveraging digitalisation to optimise their potential .
“ The result will be optimised chamber design with inclusion of different wear materials to achieve maximum wear life and the optimisation of speed to ensure only the required size of product is produced ,” they said . “ Crushing at the lowest speed acceptable ensures we achieve an acceptable product at the lowest operating cost , something that can be significantly higher in higher speed machines .”
A scanning system , already employed on FLSmidth RX50 cone crushers , which combines a 3D laser scanner and advanced software to monitor and analyse products as they leave the crusher , will help primary gyratory customers
Eriez Flotation is approaching the economic and environmental tradeoff in the comminution sector in a different way , looking at how changes to the flotation process may alleviate some of the pressure miners are experiencing .
Its HydroFloat ® technology for coarse particle flotation ( CPF ) uses a dense phase fluidised bed to increase the upper size limit of flotation by two to three times . This reduces the amount of grinding that is necessary and produces a coarser tail , which is easier to dewater and more stable for long-term storage .
The HydroFloat has been used for fertiliser minerals for almost two decades , but , in the last three years , it has been commercialised for large tonnage sulphide mining operations , starting with Newcrest ’ s Cadia Valley gold-copper operation in New South Wales , Australia .
After running a CPF demonstration plant on one line starting in 2018 , Newcrest recently announced board approval for a project to expand the CPF process to treat all of Cadia ’ s tailings with the HydroFloat .
“ This will allow them to recover a significant amount of copper and gold that is present in the coarse part of the tails ,” Eric Bain Wasmund , Eriez Flotation Global Managing Director , said . “ Eriez ’ s experience is that approximately 60 % or more of lost metal in coarse tailings can be recovered using the HydroFloat , with almost no associated incremental processing costs .”
Another benefit from the perspective of grinding is the flotation feed can be significantly coarsened because coarse ore not captured in conventional flotation will be scavenged in the HydroFloat at the end of the process .
Anglo American has recently announced it will add CPF to scavenge the tails of its greenfield Quellaveco plant in Peru , while Capstone Mining has recently reported good pilot plant results using the HydroFloat and CPF to scavenge the tails at Pinto Valley ( see IM ’ s Reprocessing and Retreatment report in this issue ).
The next evolution in the adoption of CPF is to pre-concentrate coarse feed and remove a barren tail from inside the mill circuit , which will have a more significant impact on the reduction in overgrinding , Wasmund said .
This flowsheet , which is being studied by several mining companies today , Wasmund said , is shown generically below .
Coarse Gangue Rejection Circuit Featuring the Eriez HydroFloat ®
FRESH MILL FEED
BALL MILL
CIRCULATI ING LOAD
CYCLONE UNDERFLOW
CYCLONE OVERFLOW
TO CONVENTIONAL FLOTATION
2-STAGE SCREENS
He explained : “ In this application , called Coarse Gangue Rejection ( CGR ), the HydroFloat is located in the milling circuit and used to remove coarse barren gangue particles at an average size of two-to-three-times larger than the size of particles in the conventional tailing stream .”
In a recent study titled ‘ A comparison of two circuit applications for implementation of coarse particle flotation ’, presented by Wasmund and colleagues at the 59th Meeting of the Conference of Metallurgists , it was reported that CGR could reject 30 % of the total mass of the mill feed as a coarse barren tail , allowing an estimated reduction in ball mill grinding energy of 30-50 %, and an estimated reduction in conventional flotation capacity of 40 %.
In this configuration , the HydroFloat is acting as an ore sorter by removing coarse gangue without grinding it to the final target size normally required for conventional flotation , Wasmund said .
“ Both tail scavenging and coarse gangue rejection will reduce the amount of overgrinding that is currently required by conventional flotation processes ,” he said . “ This will allow better recoveries and less energy and water consumption .”
+ 700μ
ERIEZ HYDROFLOAT ®
-160μ
COARSE BARREN TAIL
HF CONC TO REGRIND
APRIL 2021 | International Mining