【作者】 罗跃平；

【导师】 吴瑞华；

【作者基本信息】 中国地质大学（北京） ， 岩石、矿物、矿床， 2003， 硕士

【摘要】 本文通过热处理的方法，对黄色和紫色冰洲石的颜色进行改善。实验表明，冰洲石在加热到一定温度时颜色会发生变化：浅黄色、深黄色和褐黄色冰洲石分别在360-370℃、440-450℃和460-470℃完全褪色；浅紫色、深紫色和深紫红色冰洲石分别在370-380℃、440-450℃和460-470℃时完全褪色。通过对褪色后冰洲石进行紫外-可见光吸收光谱测试表明：完全褪色后的冰洲石在紫外-可见光的吸收光谱上表现为一条近平行x轴的直线；紫外、可见光区的紫区的光透过率有了很大了提高。褪色后的冰洲石晶体外观完好，其双折率、偏光性等物理性质没有明显变化，完全符合它在工业上应用的要求，冰洲石的颜色改善取得了明显的效果。 对于黄色、紫色冰洲石颜色成因，本文初步研究认为，Mn、Pb和CO₃^2-对黄色有贡献；Mn、Pb、CO₃^2-和Ni对紫色有贡献，即黄色冰洲石的致色：CO₃^2-→CO₃^-+e（V心），Mn²⁺→Mn⁺-e（F心）和Pb²⁺→pb⁺-e（F心）产生了色心，这些色心相互作用能吸收蓝区和紫区的波段，从而使冰洲石呈黄色；紫色冰洲石为CO₃^2-→CO₃^-+e（V心），Mn²⁺→Mn⁺-e（F心），Pb²⁺→Pb⁺-e（F心）和Ni²⁺→Ni⁺-e（F心）相互作用，使冰洲石呈紫色。加热使冰洲石的色心受到破坏，从而使冰洲石的颜色褪去。更多还原

【Abstract】 In this paper, the yellow and purple Iceland spars are heated to remove their color. The experiments show that the color of the Iceland spar can be changed when heated to a certain temperature, that is , light yellow Iceland spars will fade when heated to 360-370℃, while dark yellow Iceland spar will fade at 440-450℃, brownish yellow Iceland spar at 460-470℃ ; And the color of light purple Iceland spar can be removed when heated to 390-400℃, while the color of deep purple Iceland spar can be removed at 440-450℃ , deep reddish purple Iceland spar at 460-470℃ .On base of the u-v absorption spectrum, we find that the u-v absorption spectra of the faded Iceland spars are paralleled to the X axis, the transmittance of them are also greatly improved . The courses of the enhancement don’t damage Iceland spar or change its physical properties, such as birefringence index, optic chatacter. These show that the samples measure up to their industrial standards after the heating. The experiment is successful.The study on the cause of the color shows that Mn, Pb and CO2-3 are contributed to the yellow in the Iceland spar , while the purple of the iceland is caused by Mn, Pb, CO32- and Ni . The yellow Iceland spar are thus colored : CO32- can form V center in this way , CO32-→CO3-+e; Mn forms F center, Mn2+→Mn+-e ; Pb forms F center , Pb2+→Pb+-e . These color centers can affect each other and so they can absorb the purple and blue part of the visible spectrum , and make Iceland spar yellow ; similarly, CO32- (CO32-→C03-+e) ,Mn2+(Mn2+→Mn+-e) , Pb2+(Pb2+→Pb+-e) and Ni2+(Ni2+→Ni+-e) can work together to cause Iceland spar purple . Heating can bleach these color centers, consequently, the color caused by them is removed, and iceland spars become colorless.更多还原