Improving the filtration efficiency of iron ore concentrates with low SiO2 content using flocculants

This study addresses the urgent problem of enhancing the filtration efficiency of flotation iron ore concentrates characterized by low silica content (SiO2 ~2.4%) and a high proportion of slime particles (<5 μm). This challenge arises from the necessity for deep beneficiation to produce high-quality direct reduction pellets. The primary difficulty lies in the high specific cake resistance and residual moisture content of the product during the dewatering of such finely dispersed concentrates on ceramic disc vacuum filters, which are widely used in industry due to their energy efficiency. The research aimed to identify and optimize the type and dosage of flocculants for the effective aggregation of fine particles to improve filtration performance on ceramic disc vacuum filters. The influence of flocculant types on the filtration of difficult-to-dewater flotation iron ore concentrates with low SiO2 content and high slimes content was comprehensively investigated. The study materials comprised: an iron ore concentrate (69.7% total Fe, 2.4% SiO2) and two types of flocculants: a high-molecular-weight polyelectrolyte with medium anionicity based on acrylamide and sodium acrylate (Reagent A), and a polymeric coagulant with high flocculating ability, cationic in nature with high charge density based on polydiallyldimethylammonium chloride (Reagent K). The main methods included: laser diffraction particle size analysis (Fritsch Analysette 22) to assess particle aggregation; laboratory-scale vacuum filtration using a Büchner funnel at ΔP = 85 kPa to determine specific cake resistance; and measurement of residual moisture content according to GOST 12764-73. The results demonstrated that both flocculants effectively aggregated fine particles. At optimal dosages (Reagent A: 2.5–5 g/t; Reagent K: 10–20 g/t), the following were achieved: A 2.3–2.7fold reduction in the proportion of the <5 μm fraction (from 18.3 to 5.2–6.4%) due to their incorporation into larger aggregates. A 2.2–2.3-fold increase in the proportion of aggregates sized 30-44 μm (from 14.1 to 30.4–36.3%). Minimal specific cake resistance (3.3×1013 m–2 for Reagent A and 4.7×1013 m–2 for Reagent K). Reduced residual cake moisture (down to 14.12% for Reagent A and 13.57% for Reagent K, compared to 14.18% without reagents). Exceeding the optimal dosages led to gelation, increased cake resistance, and higher moisture content due to cake over-compaction.

Chylbak-ool E. D., Konyukhov Yu. V., Dmitrakovа U. V., Nikolaev A. A., Sizova A. S. Improving the filtration efficiency of iron ore concentrates with low SiO2 content using flocculants. MIAB. Mining Inf. Anal. Bull. 2025;(10):37-47. [In Russ]. DOI: 10.25018/ 0236_1493_2025_10_0_37.

E.D. Chylbak-ool^1,2, Graduate Student; Researcher, e-mail: chylbak-ool@ntcbakor.ru, ORCID ID: 0009-0007-9915-4809,
Yu.V. Konyukhov¹, Dr. Sci. (Eng.), Head of Chair, e-mail: ykonukhov@misis.ru, ORCID ID: 0000-0003-0219-4809,
U.V. Dmitrakovа², Head of the Research Center for Innovative Solutions for Dewatering and Enrichment, e-mail: dmitrakova@ntcbakor.ru,
A.A. Nikolaev¹, Cand. Sci. (Eng.), Assistant Professor, Assistant Professor, e-mail: nikolaevopr@mail.ru, ORCID ID: 0000-0003-1687-2332,
A.S. Sizova², Cand. Sci. (Eng.), Senior Researcher, e-mail: sizova@ntcbakor.ru, ORCID ID: 0009-0004-4261-6660,
¹ NUST MISIS, 119049, Moscow, Russia,
² NTC Bakor LLC, 108851, Moscow, Russia.

E.D. Chylbak-ool, e-mail: chylbak-ool@ntcbakor.ru.

1. Thang Toan Vu, Junhyeong Seo, Eunkyu Kim, Seung Gul Ryoo, Byung Cheol Park, Daesung Song Techno-economic analysis of integrated MIDREX process with CO2 capture and storage: Evaluating sustainability and viability for iron production. Process Safety and Environmental Protection. 2024, vol. 189, pp. 1314—1322. DOI: 10.1016/j.psep.2024.07.005.

2. Rumiantseva G. A., Nemenenok B. M. , Arabey A. V., Tribushevskiy L. V. «Green» technologies in metallurgical production — a dream or reality? Foundry production and metallurgy. 2022, no. 4, pp. 63—69. [In Russ]. DOI: 10.21122/16836065202246369.

3. Mokhova A. V. «Green» technologies in metallurgy. Nauka YuURGU. Sektsii tekhnicheskikh nauk. Materialy 74-y nauchnoy konferentsii [Nauka JuURGU. Technical Sciences Sections. Proceedings of the 74th scientific conference], Chelyabinsk, 2022, pp. 490—492. [In Russ].

4. Yusfin Yu. S., Pashkov N. F. Metallurgiya zheleza: uchebnik dlya vuzov [Metallurgia zheleza: textbook for universities], Moscow, Akademkniga, 2007, 464 p.

5. Pelevin A. Well. Technologies for processing Russian iron ores and improving their effectiveness. Journal of Mining Institute. 2022, vol. 256, pp. 579—592. [In Russ]. DOI: 10.31897/PMI.2022.61.

6. Varichev A. V., Kretov S. I., Kuzin V. F. Krupnomasshtabnoe proizvodstvo zhelezorudnoy produktsii v Rossiyskoy Federatsii [Large-scale iron ore production in the Russian Federation], Moscow, Izd-vo MGGU, 2010, 395 p.

7. Ismagilov R. I., Kozub A. V., Gridasov I. N., Shelepov E. V. Case study: advanced solutions applied by JSC Andrei Varichev Mikhailovsky GOK to improve ferruginous quartzite concentration performance. Russian Mining Industry Journal. 2020, no. 4, pp. 98—103. [In Russ]. DOI: 10.30686/16099192-2020-4-98-103.

8. Volovikov A. Yu. Vliyanie flotatsionnykh reagentov na fil'truyushchie svoystva keramicheskikh fil'trov pri obezvozhivanii zhelezorudnogo kontsentrata [Influence of flotation and reagent filtration properties ceramic fillets in de-energizing and iron concentrate], Candidate’s thesis, Saint-Petersburg, 2014, 20 p.

9. Dmitrakova U. V., Kruglov A. V., Chylbak-ool E. D., Yushina T. I. Experience in the use of various filtration equipment in domestic enterprises. Obogashchenie Rud. 2021, no. 4, pp. 52—56. [In Russ]. DOI: 10.17580/or.2021.04.09.

10. Krasniy B. L., Zimbovskiy I. G., Dmitrakova U. V., Chylbak-ool E. D. Chemical method waxworks filtration abilities ceramic filtration Flemings. Stahl und eisen. 2021, no. 11. [In Russ]. DOI: 10.17580/chm.2021.11.01.

11. Lavrinenko A. A., Goliberg G. Yu. In the meantime, the distance and directions of the process of separation of suspensory product enriching uglei with a sample of flocculantov. Vestnik of Nosov Magnitogorsk State Technical University. 2024, vol. 22, no. 2, pp. 58—70. [In Russ]. DOI: 10.18503/19952732-2024-22-2-58-70.

12. Khazaie A., Mazarji M., Samali B., Osborne D., Minkina T., Sushkova S., Mandzhieva S., Soldatov A. A review on coagulation/flocculation in dewatering of coal slurry. Water. 2022, vol. 14, article 918. DOI: 10.3390/w14060918.

13. Chernigov D. A., Bogorodskiy A. V., Nabiulin R. N., Mineeva T. S. Research into thickening processes of concentrates of gold-bearing ores. Proceedings of Irkutsk State Technical University. 2021, vol. 25, no. 3, pp. 391—401. [In Russ]. DOI: 10.21285/1814-3520-2021-3-391-401.

14. Meng S., Wen S., Han G., Wang X., Feng Q. Wastewater treatment in mineral processing of non-ferrous metal resources: A review. Water. 2022, vol. 14, article 726. DOI: 10.3390/w14050726.

15. Mohammed Shadi S. Abujazar, Sakine Ugurlu Karaağaç, Salem S. Abu Amr, Motasem Y. D. Alazaiza, Mohammed J. K. Bashir Recent advancement in the application of hybrid coagulants in coagulation-flocculation of wastewater: A review. Journal of Cleaner Production. 2022, vol. 345, article 131133. DOI: 10.1016/j.jclepro.2022.131133.

16. Ul'rikh E. V., Barkova A. S. Parameters of wastewater flocculation with subsequent filtration on press filters. KSTU News. 2022, no. 66, pp. 53—64. [In Russ]. DOI: 10.46845/1997-3071-202266-53-64.

17. Kozhonov A. K., Yashchuk A. A., Duyshonbaev N. P. Polymer filter on flaps without investigation of clots by flocculants to determine in the process the products of influence. Nauka vchera, segodnya, zavtra. 2016, no. 12-2(34), pp. 32—47. [In Russ].

18. Chin C. H., Muchtar A., Azhari C. H., Razali M., Aboras M. Optimization of pH and dispersant amount of Y-TZP suspension for colloidal stability. Ceramics International. 2015, vol. 41, pp. 9939— 9946. DOI: 10.1016/j.ceramint.2015.04.073.

19. Hyrycz M., Ochowiak M., Krupińska A., Włodarczak S., Matuszak M. A review of flocculants as an efficient method for increasing the efficiency of municipal sludge dewatering: Mechanisms, performances, influencing factors and perspectives. Science of The Total Environment. 2022, vol. 820, article 153328. DOI: 10.1016/j.scitotenv.2022.153328.

20. Panfilov P. F. Investigation of the effect of mixing flocculants in static mixers with suspensions of flotation waste on the effectiveness of their dewatering on a gravity table. MIAB. Mining Inf. Anal. Bull. 2005, no. 6, pp. 329—331. [In Russ].