Kinetics of Pyrite Crystallization

9526762巴恩斯等人建议测定黄铁矿从水溶液中生长的速率常数和活化能。测量将在100-300℃进行，pH值从2以下到中性。当装有多硫化物或硫酸亚铁铵溶液的压力容器被泵入含有直径约1毫米的黄铁矿种子颗粒的反应容器时，将使用流通法。反应速率常数和活化能将被测量为温度、过饱和度、多硫化物和其他含硫物质以及pH的函数。结果数据的应用范围很广。它们为评价铁和S进入沉积物的通量提供了定量依据，这是它们全球旋回的一个主要阶段。这些数据还限制了强磁性云母的形成速度及其反应形成黄铁矿的速度。根据这些信息，可以更好地理解沉积物的古地磁特征在哪里没有磁铁矿，以确定磁性状态是何时设定的以及如何保存的。由于这种矿物在含矿环境中具有很高的丰度，因此在矿产勘探中具有特别重要的应用价值。

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.