Purification of sepiolite and its dissolution in hydrochloric acid and sodium Acetate-Acetic acid buffer.

Document Type : Research Paper

Authors

Department of Soil Science, Ferdowsi University of Mashhad, Mashhad, Iran.

Abstract

The associated impurities with sepiolite, mainly palygorskite, quartz, and dolomite, reduce the industrial quality of this mineral. The objectives of this study were to i) investigate the efficiency of particle size separation for purifying sepiolite and ii) determine the kinetic dissolution of sepiolite in HCl and sodium acetate - acetic acid buffer (SAB). Bulk sepiolite was provided from a mine located around the city of Fairman, in northeastern Iran. Three particle size fractions of 20-50, <20. and <2 µm were separated from the bulk sepiolite. The XRD results showed that the particle size separation method has a great impact on reducing the amount of quartz as well as the complete elimination of dolomite in particles <2 µm and palygorskite in 20-50 µm fractions. The <20 µm fraction composed ~70% of the sample which it’s impurities considerably decreased; Therefore, it is a cost-effective fraction for industrial use. Therefore, it is a simple and low-cost physical procedure, without applying chemical reagents to achieve suitable purified sepiolite. The results of dissolution kinetic showed that the data had the best fit with the rate equation of Kt=[(1-(1-X)1/2)2]. Increasing acid concentration, temperature, and time had a direct relation, while the solid to liquid ratio had an inverse relation with the apparent rate constant. This trend was observed for SAB, too. Dissolution of sepiolite in HCl was higher than that of SAB. Acid concentration and temperature were the most effective factors on sepiolite dissolution.

Keywords


References
Abbaslou H, Jose F, Peinado M, Ghanizadeh AL, Shahrashoub M. 2023. Properties of sepiolite clay soil as a natural material (Iran’s sources clay). Geomechanics and Geoengineering, doi.org/10.1080/17486025.2023.2258833.
Allison LE. 1960. Wet combustion apparatus and procedure for organic and inorganic carbon in soil. Soil Science Society America Proceeding, 24; 36-40.
Cetisli H, Gedikbey T. 1990. Dissolution kinetics of sepiolite from Eskisehir (Turkey) in hydrochloric and nitric acids, Clay Minerals, 25; 207-215.
Draidia S, El Ouahabi M, Daoudi L, Havenith H-B, Fagel N.  2016. Occurrences and genesis of palygorskite/sepiolite and associated minerals in the Barzaman formation, United Arab Emirates. Clay Minerals, 51; 763-779
Gonzalez-Hernandez L, Ibarra-Ruoda L, Rodriguez-Dias A, Chamorro-Anton C. 1986. Preparation of amorphous silica by acid dissolution of sepiolite kinetics and textural study. Journal of Colloid and Interface Science, 109; 150-160.
Haris W, White GN. 2008. X-ray Diffraction Techniques for Soil Mineral Identification. In: Ulery AL, Drees LR, (Eds.). Methods of Soil Analysis, Part 5-Mineralogical Methods. Soil Science Society of America, Inc., Madison, Wisconsin, USA.
Ha Thuc CN, Grillet AC, Reinert L, Ohashi F, Ha Thuc H, Duclaux L. 2010. Separation and purification of montmorillonite and polyethylene oxide modified montmorillonite from Vietnamese bentonites. Applied Clay Science, 49; 220- 238.
Hojati S, Khademi H. 2011. Genesis and distribution of palygorskite in Iranian soils and sediments. In: Galan E, Singer A, (Eds.). Developments in Palygorskite-Sepiolite Research: A New Look at These Nanomaterials, Elsevier, Amsterdam, PP. 201-218.
Hojati S. 2011. Distribution patterns, genesis and stability of fibrous clay minerals in selected soils associated Tertiary sediments in Central Iran and Zagros regions. Ph.D. Thesis, Department of Soil Science, Isfahan University of Technology. (In Persian with English abstract)
Hojati S, Khademi H. 2012. Physicochemical and mineralogical characteristics of sepiolite deposits of Northeastern Iran, Scientific Quarterly Journal Geosciences. 165; 174: 23. (In Persian with English abstract)
Kadir S, Erkoyun H, Eren M, Huggett J, Önalgil N. 2016. Mineralogy, geochemistry, and genesis of sepiolite and palygorskite in Neogene lacustrine sediments, Eskkisehir province, west central Anatolia, Turkey.  64; 145–166.
Inukai K, Miyawaki R, Tomura S, Shimosaka K, Irkec T. 1994. Purification of Turkish sepiolite through hydrochloric acid treatment. Applied Clay Science, 9; 11-29.
Jacqueline AL, Teppen BJ, Boyd S. 2005. A simple method for partial purification of references clays, Clays and Clay Mineral, 53; 512- 520.
James OO, Adediran Mesubi M, Adekola A, Odebunmi O, Adekeye J.I.D. 2008. Beneficiation and characterization of a bentonite from north-eastern Nigeria, Journal of the North Carolina Academy of Science, 124; 154-158.
Kehl M, Sarvati H, Ahmadi M, Frechen M, Skowronek, A. 2006. Loess/paleosol-sequences along a climatic gradient in Northern Iran. Eisxeitalter und Gegenwart, 55; 149-173.
Khademi H, Mermut AR. 1998. Source of palygorskite in gypsiferous Aridisols and associated sediments from central Iran. Clay Minerals, 33; 561-578.
Klute A. 1986. Methodes of soils Analysis. Part 1, Physical and mineralogical methods, Soil Science Society of America Book Series Number 5, Madison, WI.
Liu X, Lu X, Qiu J, Wang Zh, Wu P. 2012. Purification of low grade Ca-bentonite for Iron ore pellets. Advanced Material Research, 454; 237-241.
Marroquin-Cardona A, Deng Y, Garcia-Mazcorro JF, Johnson NM, Mitchell NJ, Tang L, Robinson A, Taylor JF, Wang JS, Philips TD. 2011. Characterization and safety of uniform particle size NovaSil clay as a potential aflatoxin enter sorbent. Applied Clay Science, 54; 248-257.
Mirhosseini Moosavi P, Astaraei A, Karimi A, Karimi Gh. 2014. Identification and purification of montmorillonite mineral of Ghaen mine bentonite. Journal of Water and Soil, 28; 987-997. (In Persian with English abstract)
Murray HH. 2007. Applied Clay Mineralogy: Occurrence, processing and application of kaolins, bentonites, palygorskite-sepiolite, and common clays, Elsevier, Amsterdam, 180 p.
Ozdemir M, Kipçak I. 2004. Dissolution kinetics of sepiolite in hydrochloric acid and
nitric acid. Clays and Clay Minerals, 52; 714-720.
Singer A, Stahr K, Zarei M. 1998. Characteristics and origin of sepiolite (Meerschaum) from Central Somalia. Clay Minerals, 33; 349-362.
Singer A. 2002. Palygorskite and sepiolite. In: Dixon J.B. and Schulze D.G. (Eds.), Soil mineralogy with environmental applications, Soil Science Society of America, Madison, PP. 555-583.
Viseras C, Lopez- Galindo A. 1998. Pharmaceutical applications of some Spanish clays (Sepiolite, palygorskite, bentonite): some reformulation studies. Applied Clay Science, 14; 69- 82.
Yebra-Rodriguez A, Martín-Ramos D, Rey FD, Viseras C, Galindo AL. 2003. Effect of acid treatment on the structure of sepiolite. Clay Minerals, 38; 353-360
Zhou F, Yan Ch, Yan Zh, Tan J, Wang H, Zhou S, Pu S. 2016. Purification and defibering of a Chinese sepiolite. Applied Clay Science, 124- 125; 119- 126.