Kinetics of Pyrite Crystallization

PI建议确定黄铁矿在水溶液中生长的速率常数和活化能。测量将在100-300℃和pH从2以下到中性。在含有多硫化物或硫酸亚铁铵溶液的压力容器将被泵入含有直径约1mm的黄铁矿种子颗粒的反应容器中，将使用流式方法。反应速率常数和活化能将作为温度、过饱和度、多硫化物和其他含水硫化物以及ph的函数来测量。所得数据的应用是广泛的。它们为评估铁和硫进入沉积物的通量提供了定量基础，这是它们全球循环的一个主要阶段。这些数据还限制了强磁性灰长岩的形成速率及其反应生成黄铁矿的速率。根据这些信息，可以更好地解释沉积物的古地磁特征，例如，在没有磁铁矿的地方，可以确定何时设置磁性状态以及如何保存。由于这种矿物在含矿环境中丰度高，因此在矿产勘探方面的应用特别有价值。

9526762 Barnes The PI proposes to determine the rate constants and activation energies of the growth of pyrite from aqueous solutions. Measurements will be made at 100-300(C and pH from 2 below to neutrality. The flow-through method will be used where pressure vessels containing polysulfide or ferrous ammonium sulfate solutions, will be pumped into a reaction vessel containing pyrite seed grains about 1 mm in diameter. Reaction rate constants and activation energies will be measured as function of temperature, degree of supersaturation, polysulfide and other aqueous sulfur species, and pH. Applications of the resulting data are broad. They supply a quantitative basis for evaluating the flux of Fe and S into sediments, a major stage of their global cycles. The data also constrain the rates of formation of strongly magnetic greigite and of its reaction to form pyrite. From this information, the interpretation of paleomagnetic characteristics of sediments can be better understood where magnetite is absent to determine, for example, when the magnetic state was set and how it was preserved. An especially valuable application is to mineral exploration due to the high abundance of this mineral in ore-containing environments.