摘要
研究了易解石族４个变生矿物样品的物理化学性质，并得出以下五点特性：１．差热曲线特征：没变生的易解石在７００－８００℃无放热峰，而变生的就有，变生程度越深，放热峰幅度越大；２．易解石变生程度越深，矿物加热处理恢复晶态的温度越高，但不能超过１２００℃；３．易解石含放射性元素钍和铀量越高，变生程度越深；４．易解石变生程度与钍和铀的种类有关；５．４个易解石样品的化学成分：ＴｈＯ＿２和ＴｉＯ＿２、ＴｈＯ＿２和Ｎｂ＿２Ｏ＿５、Ｃｅ＿２Ｏ＿３和Ｎｄ＿２Ｏ＿３、ＴｉＯ＿２和Ｎｂ＿２Ｏ＿５都呈线型关系。
Four samples of aeschynites have been studied,including one Ce-aeschy-nite,two Nd-aeschynite, and one Y-aeschynite,of which the first three werecollected from the Bayan Obo iron and REE deposit in Inner Mongolia andthe last from Xihuashan granite in Jiangxi. The present paper deals withcharacteristics of differential thermal curves of four metamict aeschynitesamples and X-ray powder diffraction data of these samples at differenttemperatures, together with a discussion on linear relations between ThO_2 andTiO_2,ThO_2 and Nb_2O_5,Ce_2O_3 and Nd_2O_3,and TiO_2 and Nb_2O_5.From the studyit is known that the four metamict aeschynite samples have the followingcharacteristics:(1)so far as differential thermal curves are concerned, thereis no exothermal peak at 700-800℃ for aeschynites which suffered no meta-mictization,but metamict aeschynites do have such a peak,and the higher themetamictization degree,the steeper the peak;(2)the deeper the metamicti-zation,the higher the temperature of heating treatment required for restoringcrystal form of the mineral;however,the temperature should not exceed1200℃;(3)the higher the contents of radioactive elements thorium anduranium in aeschynites,the deeper the metamctization,e. g.,N0.1 sample(ThO_2 5.79%)has suffered higher degree of metamictization than N0. 2 sample(ThO_21.28%);(4)the metamictization degree of aeschynites is related tothe variety of thorium and uranium;the Main N0.1(ThO_25.79%)sample,for example,has suffered higher degree of metamictization than Y-aeschynitewhich contains 10.08% U_2O_3.
出处
《岩石矿物学杂志》
CAS
CSCD
1994年第1期67-77,共11页
Acta Petrologica et Mineralogica
基金
国家自然科学基金
关键词
变生易解石
差热分析
钍
铀
metamict aeschynite
differential thermal analysis
X-ray powder diffraction data
radioactive elements thorium and uranium
