Kinetics of roasting potash feldspar in presence of sodium carbonate

Abstract

A novel process was proposed for the utilization of potash feldspar by roasting in the presence of sodium carbonate. The effects of roasting temperature, granularity, molar ratio of sodium carbonate to potash feldspar and roasting time on the silica extraction rate were investigated. Under the optimal roasting conditions, the silica extraction rate was 98%. The optimal conditions, determined using an orthogonal experiment, were found to be roasting temperature of 875 °C, potash feldspar granularity of 74–89 μm, molar ratio of sodium carbonate to potash feldspar of 1.2:1, and roasting time of 80 min. The kinetics of potash feldspar roasting in the presence of sodium carbonate was described by the shrinking core model and the reaction rate was found to be controlled by the chemical reaction at the particle surface. According to the Arrhenius expression, the activation energy was 164.99 kJ/mol, and the process could be expressed as [1-(1-α)^1/3]=2.66×10⁵ exp[-164990/(RT)] t.

Keywords

potash feldspar / sodium carbonate / roasting kinetics / silica

References

[1] SwapanK D, KausikD. Differences in densification behaviour of K-and Na-feldspar-containing porcelain bodies [J]. Thermochimica Acta, 2003, 406: 199-206

[2] FerriL D, LotticiP P, VezzaliniG. Characterization of alteration phases on Potash-Lime-Silica glass [J]. Corrosion Science, 2014, 80(3): 434-441

[3] TalbotC J, FarhadiR, AftabiP. Potash in salt extruded at Sar Pohldiapir, Southern Iran [J]. Ore Geology Reviews, 2009, 35: 352-366

[4] MeenaV S, MauryaB R, VermaJ P. Does a rhizospheric microorganism enhance K+ availability in agricultural soils [J]. Microbiological Research, 2014, 169: 337-347

[5] GaiedM E, GallalaW. Beneficiation of feldspar ore for application in the ceramic industry: Influence of composition on the physical characteristics [J]. Arabian Journal of Chemistry, 2015, 8(2): 186-190

[6] CrundwellF K. The mechanism of dissolution of the feldspars: Part I. Dissolution at conditions far from equilibrium [J]. Hydrometallurgy, 2015, 151(1): 151-162

[7] KamseuE, BakopT, DjangangC, MaloU C, HanuskovaM, LeonelliC. Porcelain stoneware with pegmatite and nepheline syenite solid solutions: Pore size distribution and descriptive microstructure [J]. Journal of the European Ceramic Society, 2013, 33: 2775-2784

[8] ManningD, AC. Mineral sources of potassium for plant nutrition [J]. Sustainable Agriculture, 2011, 2(1): 187-203

[9] CrundwellF K. The mechanism of dissolution of the feldspars: Part II dissolution at conditions close to equilibrium [J]. Hydrometallurgy, 2015, 151(1): 163-171

[10] XuH, JannieS J D. The effect of alkali metals on the formation of geopolymeric gels from alkali-feldspars [J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2003, 216(1-3): 27-44

[11] LiuY-j, PengH-q, HuM-zhen. Removing iron by magnetic separation from a potash feldspar ore [J]. Journal of Wuhan University of Technology-Materials Science Edition, 2013, 28(2): 362-366

[12] CiceriD, ManningD A C, AllanoreA. Historical and technical developments of potassium resources [J]. Science of the Total Environment, 2015, 502(1): 590-601

[13] HynekS A, BrownF H, FernandezD P. A rapid method for hand picking potassium-rich feldspar from silicic tephra [J]. Quaternary Geochronology, 2011, 6(2): 285-288

[14] JenaS K, DhawanN, RaoD S, MisraP K, MishraB K, DasB. Studies on extraction of potassium values from nepheline syenite [J]. International Journal of Mineral Processing, 2014, 133(10): 13-22

[15] YUAN Bo, LI Chun, LIANG Bin, LV LI, YUE Hai-rong, SHENG Hao-yi, YE He-ping, XIE He-ping, Extraction of potassium from K-feldspar via the CaCl2 calcination route [J]. Chinese Journal of Chemical Engineering, 2015, 23(9): 1557–1564.

[16] ZhangY, QuC, WuJ-q, LuM, RaoP-g, LiuX-xi. Synthesis of leucite from potash feldspar [J]. Journal of Wuhan University of Technology-Materials Science Edition, 2008, 23(4): 452-455

[17] XuJ-c, MaH-w, YangJing. Preparation of ß-wollastonite glass-ceramics from potassium feldspar tailings [J]. Journal of the Chinese Ceramic Society, 2003, 31(2): 121-140

[18] KausikD, SukhenD, SwapanK D. Effect of substitution of fly ash for quartz in triaxial kaolin-quartz-feldspar system [J]. Journal of the European Ceramic Society, 2004, 24: 3169-3175

[19] NieT-m, MaH-w, LiuH, ZhangP, QiuM-y, WangLei. Reactive mechanism of potassium feldspar dissolution under hydrothermal condition [J]. Journal of the Chinese Ceramic Society, 2006, 34(7): 846-850

[20] SuS-q, MaH-w, ChuanX-yun. Hydrothermal decomposition of K-feldspar in KOH-NaOH-H₂O medium [J]. Hydrometallurgy, 2015, 156(7): 47-52

[21] HuG-r, WangJ-l, PengZ-d, DuKe. A novel method to produce potassium chromate from carbon ferrochrome [J]. Journal of Central South University, 2015, 22(4): 966-972

[22] GallalaW, GaiedM E. Sintering behavior of feldspar and influence of electric charge effects [J]. International Journal of Minerals, Metallurgy, and Materials, 2011, 18(2): 132-137

[23] FengW-w, MaH-wen. Thermodynamic analysis and experiments of thermal decomposition for potassium feldspar at intermediate temperatures [J]. Journal of the Chinese ceramic Society, 2004, 32(7): 789-799

[24] EzequielC S, EnriqueT M, CesarD, FumioS. Effects of grinding of the feldspar in the sintering using a planetary ball mill [J]. Journal of Materials Processing Technology, 2004, 152(3): 284-290