中低温成矿过程的锰镁碳酸盐矿物化学动力学与矿物成因  

Chemical kinetics of manganese and magnesium carbonate minerals during formation of epithermal-mesothermal ore deposits and their geneses

作　　者：张雪彤[1] 

机构地区：[1]中国地质科学院矿产资源研究所,北京100037

出　　处：《矿床地质》2007年第6期666-675,共10页Mineral Deposits

基　　金：科技部项目(2003AA612020-3;G1999CB403212;2003DEA2C021);国家自然科学基金项目(40043011;20373064);国土资源部项目(20010302;200010200172);大洋项目(DY105-03-01);公益性科研院所资助项目(K2007-1-13)的联合资助

摘　　要：文章使用开放流动反应装置研究了中低温热液矿床中常见脉石矿物碳酸盐(白云石、菱锰矿)在25℃～250℃水中化学动力学溶解反应速率。在25℃条件下,碳酸盐矿物的溶解速率r(Ca)>r(Mn)>r(Mg)。碳酸盐矿物在水中200℃时具有最大溶解速率。随着温度的继续升高,Mg、Mn碳酸盐的溶解反应速率会下降,容易形成白云石和锰碳酸盐。实验研究结果有助于理解中低温环境下,金属矿石的主要伴生碳酸盐矿物与水反应的化学动力学限制,试图说明中低温矿石伴随白云石和锰碳酸盐的沉淀机理。Kinetics of some carbonate minerals from mesothermal-epithermal deposits were studled by using a continuous flow reactor of an open system. The dissolution rates of dolomite and rhodochrosite were from 25 to 250 ℃. The measured dissolution rates of bivalent metal carbonate minerals at 25℃ were r （Ca） 〉 r （Mn） 〉 r （Mg）. The experimental results show that carbonate minerals have the maximal dissolution rate at 200℃. Continue to rise temperature, it would cause the decrease of dissolution rate of magnesium and manganese-carbonate minerals. This study helps us to understand the ore-forming chemical environments for accommodating carbonate under the middle-to-low temperature conditions, and also reveals the psecipitation mechanism of dolomite and manganese carbonate minerals in the temperature range from 25℃ to 250℃.

关 键 词：菱锰矿 白云石 反应动力学 中低温热液矿石 

分 类 号：O643[理学—物理化学]