Yüksek Silisli Kemiklitepe (Türkiye) Boksit Cevherinden Alkali Kavurma-Su Liçi Yöntemiyle Alüminyum Kazanımı ve Proses Optimizasyonu

Öz

Bu çalışmada, kritik bir hammadde olarak sınıflandırılan diasporik boksitten kostik soda kullanılmadan Al kazanımı için yenilikçi ve çevre dostu alternatif bir yöntem araştırılmıştır. Bu kapsamda yüksek silis içerikli boksit cevherinden alüminyum kazanımını artırmak amacıyla alkali kavurma–su liçi kombinasyonu uygulanmıştır. Proses parametrelerinin optimizasyonu ise Yanıt Yüzey Metodu (RSM) kullanılarak gerçekleştirilmiştir. Kavurma sıcaklığı, öğütme süresi ve BPR gibi temel parametrelerin Al çözünürlüğü üzerindeki etkileri, RSM tasarımı ile sistematik olarak değerlendirilmiştir. Modelin güvenilirliği ANOVA analizleriyle doğrulanmıştır. Regresyon analizleri, tüm yanıtlar için determinizasyon katsayısının (R²) %90’ın üzerinde gerçekleştiği ve model uyumunun yüksek olduğu belirlenmiştir. Optimizasyon sonuçlarına göre en uygun parametreler; 919 °C kavurma sıcaklığı, 90 dakika öğütme süresi ve 23 BPR olarak belirlenmiştir. Su liçi sonuçlarına göre, kavrulmamış cevhere kıyasla 1000 °C’de alkali kavrulan cevherde Al kazanımının yaklaşık %26 oranında arttığını ortaya koymuştur. Bulgular, yüksek silis içerikli boksitlerde alkali kavurma-su liçi yönteminin umut vaat eden alternatif bir yöntem olarak değerlendirilebilir. Ayrıca sonuçlar, prosesin endüstriyel ölçekte uygulanabilirliğine yönelik önemli bir potansiyel sunduğunu ortaya koymaktadır.

Anahtar Kelimeler

• Boksit
• aşırı öğütme
• alkali kavurma
• liç
• optimizasyon
• alüminyum.

Aluminum Recovery and Process Optimization from High-Silica Kemiklitepe (Türkiye) Bauxite Ore by the Alkaline Roasting-Water Leaching Method

Öz

In this study, an innovative and environmentally friendly alternative method was investigated for aluminum recovery from diasporic bauxite, classified as a critical raw material, without using caustic soda. Within this context, the alkaline roasting–water leaching combination was applied to enhance aluminum recovery from high-silica bauxite ore. Optimization of the process parameters was carried out using Response Surface Methodology (RSM). The effects of key parameters, roasting temperature, milling time, and ball-to-powder/ore ratio (BPR), on Aluminum (Al) dissolution were systematically evaluated through the RSM design. The reliability of the model was confirmed by ANOVA analysis, and the regression results indicated that the coefficient of determination (R²) exceeded 90% for all responses, demonstrating a strong model fit. According to the optimization outcomes, the optimum conditions were determined as a roasting temperature of 919 °C, a milling time of 90 minutes, and a BPR of 23. Water leaching results revealed that aluminum recovery increased by approximately 26% in the ore roasted at 1000 °C compared to the raw (unroasted) ore. Overall, the findings indicate that the alkaline roasting–water leaching method is a promising alternative for processing high-silica bauxite deposits.

Anahtar Kelimeler

• Bauxite
• intensive milling
• alkaline roasting
• leaching
• optimization
• aluminum.

Kaynakça

1. Jiang Y, Li W, Feng R. Preparation and performance of 4-alkyl-4,4-bis(hydroxycarbamoyl) carboxylic acid for flotation separation of diaspore against aluminosilicates. Miner Eng 2011; 24: 1571–1579.
2. Gibson B, Wonyen DG, Chelgani SC. A review of pretreatment of diasporic bauxite ores by flotation separation. Miner Eng 2017; 114: 64–73.
3. Wu Y, Pan XL, Han YJ, Yu HY. Dissolution kinetics and removal mechanism of kaolinite in diasporic bauxite in alkali solution at atmospheric pressure. Trans Nonferrous Met Soc China 2019; 29: 2627-2637.
4. Liu W, Yang J, Xiao B. Review on treatment and utilization of bauxite residues in China. Int J Miner Process 2009; 93: 220–231.
5. Sun Y, Pan A, Ma Y, Chang J. Extraction of alumina and silica from high-silica bauxite by sintering with sodium carbonate followed by two-step leaching with water and sulfuric acid. RSC Adv 2023; 13: 23254.
6. Valeev D, Shoppert A, Dogadkin D, Romashova T, Kuz’mina T, Salazar-Concha S. Extraction of Al and rare earth elements via high-pressure leaching of boehmite–kaolinite bauxite using NH₄HSO₄ and H₂SO₄. Hydrometallurgy 2023; 215: 105994.
7. Ozbag I, Togacar İ, Cinarli Yavas U, Baygül M, Turan A. Alumina extraction from diasporic bauxite via sodium carbonate-assisted roasting and water leaching. Mining Metall Explor 2025; 42:4061–4084.
8. Li Y, Pan X, Lv Z, Wu H, Yu H. Multi-element comprehensive utilization of high-silicon bauxite by roasting pretreatment and two-stage leaching. Miner Eng 2022; 187: 107805.

9. Habashi F. Handbook of Extractive Metallurgy, Vol. 2. Heidelberg, Germany: Wiley-VCH, 1997.
10. Barry TS, Uysal T, Erdemoğlu M, Birinci M. Thermal and mechanical activation in acid leaching processes of non-bauxite ores available for alumina production – Review. Mining Metall Explor 2019; 36: 557–569.
11. Erdemoğlu M, Birinci M, Uysal T. Alumina production from clay minerals: current review. J Polytechnic 2018; 21(2): 387–396.
12. Erdemoğlu M, Birinci M, Uysal T. Thermal behavior of pyrophyllite ore during calcination for thermal activation for aluminum extraction by acid leaching. Clays Clay Miner 2020; 68(2): 89–99.
13. Aydoğmuş R, Erdemoğlu M, Uysal T. Aluminum recovery by acid leaching of variously enriched pyrophyllite ore: effects of pre-treatment methods for activation. Mining Metall Explor 2023; 40: 1333–1343.
14. Baláž P, Achimovičová M. Mechano-chemical leaching in hydrometallurgy of complex sulphides. Hydrometallurgy 2006; 84: 60–68.
15. Boldyrev VV. Mechanochemistry and mechanical activation of solids. Solid State Ionics 1993; 63-65: 537–543.
16. Warris CJ, McCormick PG. Mechanochemical processing of refractory pyrite. Miner Eng 1997; 10: 1119-1125.
17. Baláž P, Achimovičová M, Billik P, Cherkezova-Zheleva Z, Criado HM, Delogu F, Dutková E, Gaffet E, Gotor FJ, Kumar R, Mitov I, Rojac T, Senna M, Streletskii A, Wieczorek-Ciurowa K. Hallmarks of mechanochemistry: from nanoparticles to technology. Chem Soc Rev 2013; 42: 7571-7637.
18. Tkáčová K, Baláž P, Mišura B, Vigdergauz VE, Chanturiya VA. Selective leaching of zinc from mechanically activated complex Cu–Pb–Zn concentrate. Hydrometallurgy 1993; 33: 291–300.
19. Tromans D, Meech JA. Enhanced dissolution of minerals: microtopography and mechanical activation. Miner Eng 1999; 12: 609–625.
20. Welham NJ. Enhanced dissolution of tantalite/columbite following milling. Int J Miner Process 2001; 61: 145–154.
21. Pourghahramani P, Forssberg E. Effects of mechanical activation on the reduction behavior of hematite concentrate. Int J Miner Process 2007; 82: 96–105.
22. Erdemoğlu M, Birinci M, Uysal T. Thermal behavior of pyrophyllite ore during calcination for thermal activation for aluminum extraction by acid leaching. Clays Clay Miner 2020; 68(2): 89–99.
23. Birinci M, Uysal T, Erdemoğlu M, Porgalı E, Barry T. Acidic leaching of thermally activated pyrophyllite ore from Puturge (Malatya-Turkey) deposit. Proc XVII Balkan Mineral Processing Congress; 1-3 November 2017; Antalya, Türkiye.
24. Uysal T, Erdemoğlu M, Birinci M. Investigation of activation conditions in alumina production from pyrophyllite ore via acid leaching method. Sci Mining J 2019; 58(2): 111–120.
25. Uysal T, Erdemoğlu M. Production of aluminum titanate from pyrophyllite ore. J Polytechnic 2021; 25(1): 313–319.
26. Li Y, Gao Y, Wang X, Shen X, Kong Q, Yu R, Lu G, Wang Z, Chen L. Iron migration and oxygen oxidation during sodium extraction from NaFeO₂. Nano Energy 2018; 47: 519–526.
27. Xue, Y., Zhang, M., Zhou, J., & Zhang, Y. Efficient Al recovery from aluminum dross with simultaneous AlN separation by a mechanical method. Waste 2023; 1(1): 40–51.
28. Uysal T. Optimization of shape factor by the response surface method, and the effect on sphalerite flotation recovery. J South Afr Inst Min Metall 2023; 123(9): 445–450.
29. Uysal T, Erust CÜ, Akça ME, Si̇s H, Erdemoğlu M. Optimization of rare earth elements recovery from Kızıldağ (Karaman–Türkiye) shale ore using response surface methodology. Physicochem Probl Miner Process 2025; 61(3): 205436.
30. Baláž P. Mechanochemistry in nanoscience and minerals engineering. Berlin, Germany: Springer, 2008.