29 kesä Compact, Combined and Co-working Pretreatments for Mining Industry ― CCCP
Name: Compact, combined and co-working pretreatments methods for mining industry
Total cost: 441 667 €, Tekes support 265 000 €
Leading research organization partner: University of Oulu/Fiber and Particle Engineering
Contact persons: Ari Ämmälä, University of Oulu, ari.ammala(at)oulu.fi
Research organization partners: Geological Survey of Finland (GTK Mintec), Process Metallurgy – University of Oulu
Company partners: Haarla, Agnico-Eagle Finland, Kemira, Mondo Minerals, Keliber
International partners: Institute for Particle Technology (IPat), Technical University of Braunschweig, Germany
Number of reviewed publications, incl. submitted manuscripts: 5
Number of other publications and reports: 2
Number of thesis: Master 2
Number of patent applications: 1 and invention disclosures: 1
Need and motivation of the project:
EU member countries consume 25–30% of metals produced globally. In contrast, metal production within the EU is only about 3% of global production. For that reason, European industry is vulnerable to disruptions in metal supply and to market volatility. In Finland, it can be seen that there is a great potential for new mines in near future and they will provide jobs and well-being for numerous Finnish citizens particularly in rural areas. There are, however, some key challenges which must be met in order to maintain the present success in domestic mining industry. Main challenges relate to distinctive quality of ore minerals and the fact that we must be able to benefit deposits of lower grades in connection to the increasing demand of sustainability including minimization in water and energy usage as well as environmental load.
Main set targets:
The aim of the project was to find out novel methods and intensified beneficiation routes for given ore types (including ferrous, base, precious and high-tech metals) in order to improve recovery, capacity and energy use while keeping environmental impact as low as possible during the life span of mines. Tools for that were thermal, mechanical or chemical preparative treatment i.e. conditioning like microwave treatment, additional grinding intensified by chemicals or functional chemicals between sequent or within preceding unit processes.
In the project was shown that the conversion of spodumene can be achieved more rapidly with hybrid microwave heating than with conventional heating. Furthermore, the screening separation proved to be a noteworthy method for the additional enrichment of converted spodumene concentrate.
In the project was found that depending on the processed ore type, the selectivity of mineral separation in flotation can be improved by applying high-intensity shear pretreatment prior to flotation. The findings led to the survey of patenting possibility. During the project it was also showed that functionalized nanocelluloses are promising green alternatives for current chemicals used in flotation. The project results were a base for the continuation project of nanocellulose-based chemicals for flotation, flocculation, dewatering, and water purification in mining industry (ERA-MIN CELMIN-project).
To minimize the consumption of copper sulfate activator in the flotation of gold (case Kittilä) following methods were suggested i) high intensity conditioning, ii) decreasing the pulp pH from natural, iii) using nitrogen in grinding and/or flotation, and iv) adding small dosages of CuSO4 in stages instead of one large dosage at one step. The results from case Vuonos suggested that both nickel recoveries and nickel flotation kinetics could be improved by applying high intensity conditioning (HIC) or high-intensity shear treatment (ZRI) with flotation reagents or combination of HIC and grinding prior to flotation. Also higher mixing speed in flotation improved the nickel flotation kinetics. The most cost effective way to improve the nickel recovery in Vuonos might be obtained by classifying and reporting the coarser particles in the cyclone overflow stream back to nickel flotation.
Commercialization measures and/or potential:
All the pretreatment methods or changes in processing conditions suggested in this project could be applied and tested in the industrial scale. High intensity pretreatment is a potential method for the pretreatment of ores or tailings before flotation. Based on the invention disclosure made in the CCCP project, Haarla Oy launched its own research and development project in order to commercialize the results. Patent is pending for the method.
List of publications
Scientific papers and conference presentations
- Laitinen O, Kemppainen K, Ämmälä A, Sirviö J, Liimatainen H, Niinimäki J: Use of chemically modified nanocelluloses in flotation of hematite and quartz. Industrial & Engineering Chemistry Research, 2014, 53(52), 20092-20098.
- Kemppainen K, Laitinen O, Ämmälä A: Effect of high-intensity shear and ultrasound pre-treatments on flotation selectivity of dry ground and wetted talc ore. (Will be submitted after patenting)
- Kemppainen K, Suopajärvi T, Laitinen O, Ämmälä A, Liimatainen H: Flocculation of fine hematite and quartz with anionic cellulose nanofibers. Chemical Engineering Science DOI: 10.1016/j.ces.2016.04.014
- Peltosaari O, Tanskanen P, Heikkinen E-P, Fabritius T: α→γ→β-phase transformation of spodumene with hybrid microwave and conventional furnaces. Minerals Engineering, 2015.
- Peltosaari O, Tanskanen P, Heikkinen E-P, Fabritius T: α→γ→β-phase transformation of spodumene with hybrid microwave and conventional furnaces. Conference presentation, MEI Process Mineralogy ’14, Cape Town, South Africa, 17-19.11.2014.
- Hautala S: Spodumeenin lämpökäsittelyn jälkeinen seulontarikastus. University of Oulu. 2014.
- Peltosaari O: Spodumeenirikasteen lämpökäsittely mikroaaltotekniikalla. University of Oulu. 2013.
- Ämmälä A, Kemppainen K, et al., Method for improving separation of mineral particles, 2016. Patent pending.
- Kemppainen K, Laitinen O, Ämmälä A, Peltosaari O, Tanskanen P, Hautala S, Compact, combined and co-working pretreatments methods for mining industry – CCCP 1.1.2013-30.06.2015. Final report of University of Oulu. October 2015. 66 p.
- Taskinen A, Korhonen T, and Neitola R, Compact, combined and co-working pretreatment methods for mining industry (CCCP): Final report of GTK, October 2015.59 p.
- Ämmälä A, Mechanical pretreatment of minerals to enhance flotation selectivity. Tekes Green Mining Programme: Development of mineral processing technology 25.8.2015, University of Oulu.
- Laitinen O, Potential use of cellulose based chemicals in mineral processing. Tekes Green Mining Programme: Development of mineral processing technology 25.8.2015, University of Oulu.
- Taskinen A, Optimizing the usage of copper sulfate in the flotation of a gold ore. Tekes Green Mining Programme: Development of mineral processing technology 25.8.2015, University of Oulu.
- Taskinen A, Optimizing the usage of copper sulfate in the flotation of a gold ore. Eco-efficient mining research seminar at GTK Kuopio (June 6, 2015)