摘要:
柠檬酸钠-重碳酸钠-连二亚硫酸钠(CBD)是否可以区分土壤和沉积物中碎屑成因和成土成因铁氧化物,是否可以溶解粗粒级的铁氧化物矿物存在诸多争议。为此,研究了各种粗粒级(>63μm)铁氧化物在室温和加热条件下CBD处理铁溶出量随时间的变化。结果表明,即使在室温条件下,CBD也能够溶解粗颗粒(>63μm)的铁氧化物,在CBD中溶解速度最大的是赤铁矿,铁的溶出量较多的是针铁矿,溶解速度较慢的是磁铁矿;在加热条件下,各种铁氧化物溶出量都整体升高。黄铁矿高温煅烧转化形成的赤铁矿,在常温和加热条件下溶出量相对较多,说明粒径越小,溶出量越大。
Abstract:
It has been disputed whether eitrate-biearbonate-dithionite (CBD) can distinguish between lithegenie and pedogenie iron oxides or can solve coarse particles of iron oxide. Therefore, we used CBD technique to make an experiment on the extracted amount of different coarse particles (>63 μm) of iron oxide that vary with time at the room temperature and heated conditions. The results show that CBD technique can dissolve coarse particles (>63 μm) of iron oxide in the room conditions, and hematite was dissolved most quickly,the largerst dissolved amount came from goethite and the lowest dissolved rate was showed by magnetite. Meanwhile, the dissolved amount of all iron oxides went higher in the heated conditions. Pyrite was calcined at 400℃ and 500℃ and formed hematite,and their amounts reached the maximum in the same conditions, indicating that the smaller, the grain size,the larger,the dissolved amount.
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