ORE SORTING
separation objective and magnetic susceptibility of the minerals being processed .
The magnetic field is intensified on the points of the matrix and there are various designs of matrix to suit different minerals applications and particle size ranges ( down to < 2 μ ).
In operation , an initial evaluation of the test material determines the type of matrix and the level of magnetic field required to meet the customers objectives . The magnetic field of the laboratory WHIMS is calibrated using the calibration graph ( provided with each laboratory WHIMS ). The graph shows the relative magnetic field ( in gauss ) at different current levels ( in amps ) with and without the matrix . The requisite level of amps to project the required magnetic field is set on the control panel . As the magnetic field rises , the increased magnetic field strength and gradient enables the capture of weaker and para magnetic minerals .
Once the matrix and magnetic field test parameters are set , the laboratory WHIMS is activated with material gravity fed in a 15-20 % w / w suspension through the central matrix . Any residual material in the feed container is washed out into the matrix using a known volume of wash water .
The non-magnetic minerals and the water flow through the matrix are collected in a receptacle underneath . Magnetic particles are held in the matrix by the magnetic field . To remove a small proportion of non-magnetics potentially entrapped in the matrix , water is flushed through with the magnetic field still on .
The non-magnetic receptacle is then replaced for collection of the magnetics fraction . The magnetic field is turned off , which releases the magnetically trapped particles . The matrix is once again flushed through several times with water to ensure the matrix is empty . Commonly , both samples are then dried before being analysed .
The laboratory-scale WHIMS is an extremely versatile high intensity magnetic separator used globally in mineral processing .
Neil Rowson , Bunting ’ s Laboratory Manager , said : “ The need to process increasingly difficult deposits and recycle materials previously classed as ‘ waste ’ is driving a demand for high-intensity magnetic separation . Bunting already conducts extensive test work for the consultancy at our Customer Experience Centre in Redditch , but with an increasing number of projects the consultant wanted to expand their own test capabilities .”
Quantifying value in each blast design
In recent years , Orica has branched out of its explosives and blasting niche and created an Orebody Intelligence business that covers major parts of the mining flowsheet .
Just this year , it made inroads into the material classification space through the development of its OREPro™ 3D Predict modelling software .
In announcing the launch , Orica said it was opening the door to “ iterative designs and the quantification of value in each blast design ”.
Over 30 years of research and development , coupled with significant cloud-based computing power , have led to the creation of OREPro 3D Predict software , which is at its heart a blast movement simulator and grade control polygon optimiser . The solution leverages the power of Orica ’ s original OREPro 3D modelling expertise with the addition of the enhanced predictive SmartVector™ technology .
Using readily available mine data as inputs , including blast designs and in-situ block models , physics-based algorithms predict movement dynamics throughout the entire blast volume to create a “ swelled post-blast grade control block model ”. The polygon optimisation tools will then suggest delineations that can help achieve the highest value possible , according to Orica .
Orica Vice President Digital Solutions , Rajkumar Mathiravedu , said : “ With OREPro 3D Predict , our customers can now predict blast results , allowing blast designers to rapidly create blasts that increase value in near real time instead of waiting until the blast is excavated to understand the impacts .”
Understanding where the rock mass has moved during the blast is critical to separating ore and waste effectively and creating downstream efficiencies in the mining process , as many of the ore sorting vendors contacted for this article know . OREPro 3D Predict takes this a step further by simulating post-blast topography when it cannot be surveyed safely , handling complex boundary conditions with ease and providing enhanced transparency by animating the entire predicted movement , Orica said .
OREPro 3D Predict , the company says , further enhances Orica ’ s Digital Solutions offering by
Understanding where the rock mass has moved during the blast is critical to separating ore and waste effectively and creating downstream efficiencies in the mining process , and that is where Orica ’ s OrePro 3D Predict can help
allowing customers to plan effectively and track material through complex interactions with the surrounding geology .
This product is a cornerstone of iterative optimisation and complements the reactive software OREPro 3D , creating value for customers through a complete grade control workflow offering , it added .
Mathiravedu told IM that OREPro 3D Predict includes many QA / QC checks to ensure the data entered into the software is valid , while the future integration of Orica ’ s BlastIQ™ platform – and products like SHOTPlus™ and FRAGTrack – with the OREPro suite of software provides a seamless link between the data gathered and data entered . This could see blast designs created in SHOTPlus and simulated in OREPro 3D Predict .
Mathiravedu explained : “ FRAGTrack collects post-blast data that informs users of the blast ’ s performance , allowing them to better understand the blast impact . BlastIQ then stores the blast information in the cloud , enabling digital management of the overall drill and blast operations .”
Orica works with its customers to increase the accuracy of the models and inputs , thereby increasing the accuracy of the outputs without the need for hardware or walking on muckpiles . Mathiravedu said : “ Additionally , advice is sometimes provided on ways to better use the insitu orebody – from value-based routing and decision tree logic to mining directions and methods . Upstream , Orica Digital Solutions has invested heavily in orebody intelligence , which helps mines to better define the in-situ properties of their rock mass , leading to higherquality block models .” IM
50 International Mining | MARCH 2023