为了探明豫西地区铝土矿的部分矿石煅烧时易胀裂的原因，借助于扫描电镜和能谱分析，确认了含K2 O较多的豫西铝土矿中赋存明矾石，研究了其赋存状态及其在受热过程中的变化。明矾石的典型结晶形状显示为立方体，多在5μm 以下，EDS 分析测得化学组成（w）范围为：Al2O343．4％～44．4％，SO344．6％～46．3％，K2O 7．0％～8．8％，Na2O 2．3％～3．4％。明矾石多呈不均态富集或与云母、高岭石呈共生结构，借助形貌特征易于分辨。铝土矿经1000℃3 h热处理后，其中的明矾石熔融，形成玻璃相，经EDS分析显示，S元素消失殆尽，表明以SO3形式燃烧掉；但K元素尚存，构成了玻璃相的成分。经1200℃3 h热处理后，明矾石完全熔融形成较稀薄的液相，从中析出细微的柱状刚玉，液相的典型组成（w）为：Al2O347．7％，SiO243．8％， K2O 4．9％，TiO23．6％。含有明矾石的铝土矿经1400℃3 h 热处理后严重爆裂成碎片，是因硫的激剧燃烧所致。
In order to research the reason that some bauxite in the west of Henan Province is easy to spall during calcination,alunite crystallized in bauxite containing more K2 O (>1%,in mass,the same hereinaf-ter)from the west of Henan Province was confirmed,and its crystallization state and its change during heating were researched by SEM and EDS.The typical alunite crystals are cubic and are smaller than 5 μm in size mostly.The chemical compositions of alunite determined by EDS are:Al2O3 43.4%-44.4%,SO3 44.6%-46.3%,K2O 7.0%-8.8%,and Na2O 2.3%-3.4%.Alunite is in uneven enrichment state or coex-ists with muscovite or kaolinite,which can be distinguished by their morphology features.When the bauxite is heated at 1 000 ℃ for 3 h,the alunite melts and forms glassy phase.EDS analysis shows that element sulfur disappears completely,which means it’s burned out in the form of SO3,but element potassium dis-solves in glassy phase.With temperature rising to 1 200℃and soaking for 3 h,the alunite melts completely forming dilute glassy phase and from which small columnar corundum crystallizes.The typical composi-tions of the glassy phase are:Al2O3 47.7%,SiO2 43.8%,K2O 4.9%,and TiO2 3.6%.When heated at 1 400℃ for 3 h,the bauxite containing alunite cracks into pieces seriously,which is resulted from the intense burning of sulfur.
参考文献
| [1] | 高振昕;李广平 .中国高铝矾土分类的研究[J].硅酸盐学报,1984,12(02):243-250. |
| [2] | 俞缙;李普涛;于航波.靖西三合铝土矿铝矿物特征及成因机制[J].华东理工大学学报,2009(04):344-349. |
| [3] | 王庆飞,邓军,刘学飞,张起钻,李中明,康微,蔡书慧,李宁.铝土矿地质与成因研究进展[J].地质与勘探,2012(03):430-448. |
| [4] | 刘学飞,王庆飞,李中明,冯跃文,蔡书慧,康微,王佳奇,江露露.河南铝土矿矿物成因及其演化序列[J].地质与勘探,2012(03):449-459. |
| [5] | Al-Momani T M .Occurrences and origin of alunite,south Jordan[J].Journal of Applied Science,2007,7(08):1230-1234. |
| [6] | Fink W L;VanHorn K R;Pazour H A .Thermal decomposition of al-unite[J].Industrial and Engineering Chemistry,1931,23(11):1248-1250. |
| [7] | Ogburn S C;Stere H B .Thermal decomposition of alunite[J].Industrial and Engineering Chemistry,1932,24(03):288-290. |
| [8] | Bayliss N S;Cowley J M;Farrant J L.The thermal decomposition of synthetic and nature alunite:an investigation by X-ray diffraction, and electron microscope methods[J].Aust J Sci Res,1948(01):343-350. |
| [9] | Kashkai MA;Babaev I A .Thermal investigations on alunite and its mixtures with quartz and dickite[J].Mineralog Mag,1969,37(285):128-134. |
| [10] | Kucuk F;Yildiz K .The decomposition kinetics of mechanically activated alunite ore in air atmosphere by thermogravimetry[J].Thermochimica Acta: An International Journal Concerned with the Broader Aspects of Thermochemistry and Its Applications to Chemical Problems,2006(2):107-110. |
| [11] | 高振昕,刘百宽,贺中央,范青松,傅秋华,王米娜,李君霞.水铝石热分解的晶体形貌[J].硅酸盐学报,2011(10):1570-1575. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%