Axial or turn-by-turn particle recovery in a spiral concentrator

ABSTRACTSpiral concentrators (“spirals”) are commonly used to separate valuable heavy minerals from light gangue minerals by gravity. This paper examines the classification of particles as they flow down a spiral concentrator and relates the results to the number of turns. The tests show the possibility of reproducing the performance of industrial spirals with a spiral operating in a closed circuit in a laboratory. Results show that knowing the mineral size distributions in the spiral feed is necessary to forecast spiral performance. Further, in the case of iron ore processing, the separation process is practically complete after four turns, with wash water affecting the process rate of recovery. This observation is readily explained by considering the mineral size distribution.RÉSUMÉLes spirales gravimétriques (“spirales”) sont couramment utilisées pour séparer par gravité les minéraux lourds précieux des minéraux légers de gangue. Cet article examine la classification des particules qui s’écoulent le long d’une spirale et met en relation les résultats avec le nombre de tours. Les tests montrent qu’il est possible de reproduire les performances des spirales industrielles avec une spirale fonctionnant en circuit fermé dans un laboratoire. Les résultats montrent qu’il est nécessaire de connaître la distribution par tailles des minéraux dans l’alimentation de la spirale pour prévoir les performances de celle-ci. De plus, dans le cas du traitement du minerai de fer, le processus de séparation est pratiquement terminé après quatre tours, l’eau de lavage affectant le taux de récupération du procédé. Cette observation s’explique facilement si l’on considère la distribution par tailles des minéraux.KEYWORDS: Grade-recovery curve, Gravity concentration, Iron ore, Partition curve, Spiral concentratorMOTS-CLÉS: concentration par gravité, courbe de partage, courbe récupération-teneur, minerai de fer, spirale gravimétrique ACKNOWLEDGMENTSThis project was made possible by a grant from the Quebec Government via the Fonds de recherche du Québec – Nature et technologies (FRQNT) organization. The financial support of the company ArcelorMittal Mining Canada is also acknowledged. Finally, the authors thank Minerals Technologies for allowing the purchase of the WW6Plus spiral for the test work.DISCLOSURE STATEMENTNo potential conflict of interest was reported by the authors.REVIEW STATEMENTThis article was reviewed and approved for publication by the Canadian Mineral Processing Society of the Canadian Institute of Mining, Metallurgy and Petroleum.ETHICS APPROVAL AND CONSENT TO PARTICIPATEThere are no ethical issues associated with this manuscript.Additional informationFundingThis work was supported by the Fonds de recherche du Québec - Nature et technologies (FRQNT-2020-MN-284070 and FRQNT-2015-MI-191774).Notes on contributorsL. BoisvertLaurence Boisvert is a Candidate to the Engineering Profession (CEP), currently working at Corem as a physical separation researcher. He graduated from Laval University in 2020, where he is currently completing his Master’s degree in mining and metallurgical engineering.M. SadeghiMaryam Sadeghi is a metallurgist at CIMA+ with 11 years of engineering experience, including 7 years in a manufacturing environment. She has been working with consulting engineering firms since 2019. She completed her bachelor’s degree in mining engineering in her home country, Iran, in 2004. She arrived in Canada in 2012 to pursue her studies in mineral processing at Laval University, where she earned her Master’s degree in 2014 and her PhD in mining engineering in 2021. Her research focus is primarily iron ore processing, and her projects are mainly related to process design and optimization.C. RochefortChristian Rochefort is a mineral processing engineer holding bachelor’s and master’s degrees from Laval University. He has more than 20 years of experience in the mining industry, working on research and development and process development projects. He specializes in grinding, physical separation, and flotation of iron ore. He currently holds the position of Expert in Mineral Processing at ArcelorMittal Mining Canada.C. BazinClaude Bazin graduated with a bachelor’s degree in metallurgical engineering from Laval University in 1980. He obtained a PhD in 1991. From 1987 to 1990, he worked for Brunswick Mining and Smelting (Noranda) as a Research Engineer and Process Control Engineer, before accepting the position of Senior Metallurgist at the Heath Steele concentrator in New Brunswick. In 1992, he accepted the position of Professor at Laval University, a position he still holds.