The electrical property of micrometre-sized graphite particles was investigated under different particle concentration, particle size, fluid conductivity and pH conditions. Due to its large internal electronic conductivity and ability to polarize under external potential field, significant enhancement of its spectral induced polarization (SIP) responses is observed when graphite is included in sand mixtures. While a small amount of graphite inclusion significantly increases the SIP response of its mixtures with sand, further concentration increase does not necessarily lead to a proportional increase of the SIP response. This is shown to be related to the formation of graphite aggregates at higher concentrations. Changes of fluid salinity have a significant effect on graphite's SIP behaviour. This includes a positive impact on normalized chargeability and imaginary conductivity, but a negative impact on chargeability and relaxation time constant. The effect of pH on the SIP response of graphite is small but shows consistent trend, where pH increase leads to a decrease of both the chargeability and relaxation time constant. The underlying cause of this effect is not clear.

中文翻译：

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盐度和pH值对石墨粒子光谱极化信号的影响

在不同的颗粒浓度，颗粒大小，流体电导率和pH条件下，研究了微米级石墨颗粒的电性能。由于其较大的内部电子电导率和在外部电势场下极化的能力，当在沙子混合物中包含石墨时，观察到其光谱感应极化（SIP）响应显着增强。尽管少量的石墨夹杂物会显着增加其与沙子的混合物的SIP响应，但进一步的浓度增加并不一定会导致SIP响应按比例增加。已表明这与较高浓度的石墨聚集体的形成有关。流体盐度的变化对石墨的SIP行为有重要影响。这包括对归一化充电率和虚构电导率的正面影响，但对充电率和弛豫时间常数的负面影响。pH对石墨的SIP反应的影响很小，但显示出一致的趋势，其中pH的增加导致带电性和弛豫时间常数的降低。这种作用的根本原因尚不清楚。