Abstract
Fine-grained hematite ore can be concentrated by the process of selective flocculation and dispersion, which relies on proper reagent selection and control of water chemistry. While many previous studies have been performed analyzing the effects of different reagents on this process in a laboratory environment, this paper focuses on investigating the water chemistry within the process in a pilot-scale continuous deslime thickener.
The pH, sodium concentration, calcium concentration and magnesium concentration were varied to determine their effects on the iron concentrate grade and recovery, and the phosphorus concentrate grade and rejection in the pilot-scale selective deslime thickener. The ideal pH for the iron grade and recovery of the process using a starch selective flocculant was found to be 10.5. Phosphorus rejection, however, was increased at lower pH values. Minimization of sodium concentration was shown to improve iron grade, iron recovery and phosphorus rejection. Calcium acted as a nonselective flocculant showing higher iron recovery, lower iron grade and lower phosphorus rejection with increasing concentration. Conclusions could not be drawn from the experiments that varied magnesium concentration.
The zeta potential of the solid-liquid interface of particles in each sample taken was also analyzed to show relationships between zeta potential and process performance. In all cases, a maximization of the magnitude of zeta potential correlated with increased iron grade and recovery. This supports the hypothesis that a higher level of dispersion enhances the selective flocculation and separation process.
This is a preview of subscription content, access via your institution.
References
ASTM Standard E1070-11, 2011, “Standard Test Method for Determination of Phosphorus in Iron Ores by Phospho-Molybdenum-Blue Spectrophotometry,” ASTM International, West Conshohocken, PA, 20011, doi: 10.1520/E1070-11.
Bolen, J., 2014, “Modern air pollution control for iron ore induration,” Minerals & Metallurgical Processing, Vol. 31, No. 2, pp. 103–114.
Carlson, J.J., and Kawatra, S.K., 2008, “Effect of particle shape on the filtration rate in an industrial iron ore processing plant,” Minerals & Metallurgical Processing, Vol. 25, No. 3, pp. 165–168.
Carlson, J.J., and Kawatra, S.K., 2013, “Factors affecting zeta potential of iron oxides,” Mineral Processing and Extractive Metallurgy Review, Vol. 34, No. 5, pp. 269–303.
Cliffs Natural Resources, 2011, “Steel Starts Here,” Cleveland, OH.
Department of Energy, 2001, “Selective Flocculation of Fine Mineral Particles,” Office of Industrial Technologies Energy Efficiency and Renewable Energy — U.S. Department of Energy, Washington D.C.
Dzombak, D.A., and Morel, F., 1990, Surface Complexation Modeling: Hydrous Ferric Oxide, Wiley, p. 393.
Green, R.E., and Colombo, A.F., 1984, “Dispersion-Selective Flocculation-Desliming Characteristics of Oxidized Taconites,” US Bureau of Mines, Report of Investigations, RI 8867, 24 pp.
Halt, J.A., Roache, S.C., and Kawatra, S.K., 2014, “Cold bonding of iron ore concentrate pellets,” Minerals Processing & Extractive Metallurgy Review, forthcoming, doi: 10.1080/08827508.2013.873863.
Halt, J.A. and Kawatra, S.K., 2014, “Review of organic binders for iron ore concentrate agglomeration,” Minerals & Metallurgical Processing, Vol. 31, No. 2, pp. 72–94.
Haselhuhn, H.J., 2012a, “The Effect of CO2 Sparging on the Flocculation and Filtration rate of Concentrated Hematite Slurries,” SME Annual Meeting, Preprint 12-088.
Haselhuhn, H.J., 2012b, “Water chemistry effects on the zeta potential of concentrated hematite ore,” Minerals & Metallurgical Processing, Vol. 29, No. 2, pp. 135–136.
Haselhuhn, H.J., 2013a, “The Role of Water Chemistry in the Concentration of Hematite Ore,” Masters Thesis, Michigan Technological University.
Haselhuhn, H.J., 2013b, “Dispersant adsorption and effects on settling behavior of iron ore,” Minerals & Metallurgical Processing, Vol. 30, No. 3, pp. 188–189.
Iwasaki, I., 1989, “Bridging theory and practice in iron ore flotation,” Advances in Coal and Mineral Processing Using Flotation, S. Chander and R. Klimpel, eds., SME, pp. 177–190.
Kitamura, A., Fujiwara, K., Yamamoto, T., Nishikawa, S., and Moriyama, H., 1999, “Analysis of adsorption behavior of cations onto quartz surface by electrical double-layer model,” Journal of Nuclear Science and Technology, Vol. 36, No. 12, pp. 1167–1175.
Liu, S., Wang, W., Zhang, M., and Wen, S., 2014, “Beneficiation of a low grade hematite-magnetite ore in China,” Minerals & Metallurgical Processing, Vol. 31, No. 2, pp. 136–142.
Manouchehri, H.R., 2014, “Pyrrhotite flotation and its selectivity against pentlandite in the beneficiation of nickeliferous ores: An electrochemistry perspective,” Minerals & Metallurgical Processing, Vol. 31, No. 2, pp. 115–125.
Parkhurst, D.L., and Appelo, C.A.J., 2013, “Description of Input and Examples for PHREEQC Version 3—A Computer Program for Speciation, Batch-reaction, One-dimensional Transport, and Inverse Geochemical Calculations: U.S. Geological Survey Techniques and Methods,” US Geological Survey, http://pubs.usgs.gov/tm/06/a43/.
Pradip, 1994, “Reagents design and molecular recognition at mineral surfaces,” Reagents for Better Metallurgy, P. Muluktla, ed., SME, pp. 245–252.
Sandvik, K.L., and Larsen, E., 2014, “Iron ore flotation with environmentally friendly reagents,” Minerals & Metallurgical Processing, Vol. 31, No. 2, pp. 95–102.
Semberg, P., Andersson, C., and Bjorkman, B., 2014, “Interaction between iron oxides and olivine in magnetite pellets during reduction 500-1,300°C,” Minerals & Metallurgical Processing, Vol. 31, No. 2, pp. 126–135.
Siirak, J., and Hancock, B.A., 1988, “Progress in developing a flotation phosphorus reduction process at the Tilden Iron Ore Mine,” XVI International Mineral Processing Congress, K.S.E. Forssberg, ed., June 5–10, 1988, Stockholm, Sweden, Elsevier, pp. 1393–1404.
Tuck, C.A., 2013, “Mineral Commodity Studies — Iron Ore,” U.S. Geological Survey, January 2013.
Weissenborn, P.K., 1996, “Behaviour of amylopectin and amylose components of starch in the selective flocculation of ultrafine iron ore,” International Journal of Mineral Processing, Vol. 47, No. 3–4, pp. 197–211.
Author information
Authors and Affiliations
Corresponding author
Additional information
Paper number MMP-14-038.
Discussion of this peer-reviewed and approved paper is invited and must be submitted to SME Publications Dept. prior to November 30, 2015.
Rights and permissions
About this article
Cite this article
Haselhuhn, H.J., Kawatra, S.K. Role of water chemistry in the selective flocculation and dispersion of iron ore. Mining, Metallurgy & Exploration 32, 69–77 (2015). https://doi.org/10.1007/BF03402423
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF03402423
Key words
- Iron ore
- Water chemistry
- Flocculation
- Hematite
- Slimes