苏南锶矿成矿作用讨论

近年来在长江中下游的溧水和宁芜火山岩盆地不断发现一些与火山碎屑岩有关的锶矿床和含锶重晶石,本文通过阐述这些矿床的地质特征,分析其成矿作用,为今后火山热液型锶矿的找矿工作提供理论依据。     

爱景山锶矿床的生物地球化学异常

爱景山天青石矿床位于长江中下游的溧水中生代火山岩断陷盆地中,矿体受断裂带控制,与龙王山组晶屑凝灰岩有密切的成因联系,是近年来新发现的火山热液型锶矿床。笔者在矿区踏矿时,发现长江中下游常见的植物种属呈现生态变异现象,其典型特征是植物的株、叶发红。为探明原因,在爱景山矿段,卧龙山矿段采集了18个种属近40个植物样品,为了进行对比,在南京近郊也采集了相同种属的近20个样品。原始样品在日光下干燥后,于500℃马弗炉中灰化,其灰分用发射光谱进行了半定量全分析。初步研究表明,爱景山锶矿床存在明显的生物地化异常,这种生物地化异常可作为该类型矿床的找矿标志。     

Geochemistry of the Baishitouquan Amazonite—and Topaz—bearing Granite in the Mid—Tianshan Belt,Xinjiang,China

The Baishitouquan amazonite and topaz-bearing granite is one of the typical high-rubidium and high-fluorine granites in the eastern part of the Mid-Tianshan belt. This intrusion is in sharp contact with Mid-Proterozoic schists, gneisses and marbles, and is composed of four zones transitional from the bottom upwards: leucogranite, amazonite granite, topaz-bearing amazonite granite and topaz quartz albitite. The Baishitouquan granite contains highly ordered K-feldspar, Li-rich mica, Mn-rich garnet, α-quartz and low temperature zircon and is chemically high in Si, K, Na, Al, Li, Rb, Cs and F, and low in Ti, Fe, Ca, Mg, P, Co, Ni, Cr, V, Sr and Ba, with Na₂O<K₂O. Amazonite from the amazonite granite zone contains 1867 ppm Rb. The F contents of bulk rocks are 3040 and 4597 for the amazonite granite and topaz-bearing amazonite granite zones, respectively. These two zones have δ¹⁸O values of 8.97–9.85‰ (SMOW) and show flat REE distribution patterns with strong Eu depletion. K-Ar and Rb-Sr ages of this intrusion are 226. 6 Ma and 209. 6 Ma respectively, with an initial⁸⁷Sr/⁸⁶Sr ratio of 0.987±0.213. The Baishitouquan granite is the product of crystallization of a low temperature, and water, rubidium and fluorine-rich magma, which may have been derived from partial melting of muscovite-rich crustal rocks. Consolidation of this granite involved two contrasting and successive stages: melt crystallization and hydrothermal metasomatism and precipitation. Various geological features of this granite were formed during the transition from the magmatic to the hydrothermal stage.     

用天青石矿制高纯碳酸锶

首先将天青石与碳酸铵反应得到的粗碳酸锶，通过酸溶、精制、碱析得到氢氧化锶，后加水制浆，同碱金属碳酸盐反应生成碳酸锶沉淀和含苛性碱的母液，经分离、水洗、干燥，得高纯碳酸锶，含苛性碱的母液可循环用于碱析工序。该方法生产的碳酸锶含量大于99%，且生产成本低，应用范围广泛。