浸泡与否对岩矿石密度测定的影响

The effect of soaking or not on the density determination of rock and ore

岩石密度测定是获取准确密度值的重要手段,同时密度也是对重力测量结果进行地形校正和中间层校正不可缺少的参数。密度测定精度越高,利用其进行地质解译的精度也越高,但不同版本的测定规范对岩石密度测定前是否需要浸泡处理存在分歧。本文以白云鄂博矿区12种岩(矿)石标本为例,对比浸泡前后的密度变化,得出除云母型铁矿石外,浸泡后的岩石密度均不同程度增大。对于孔隙或裂隙发育的岩(矿)石,浸泡后的密度差百分比大于0.5%。而结构致密的岩(矿)石,浸泡对密度测定的影响低于2倍测定误差,可忽略不计。

Rock density determination is an important method to obtain accurate density values,and it is also an indispensable parameter for topographic correction and middle layer correction of gravity measurement results.The higher the accuracy of density measurement,the higher the accuracy of geological interpretation.However,there are different opinions on whether soaking treatment is needed before the determination of rock density in different versions of measurement specification.In this paper,we taking 12 kinds of rock(ore)specimens in Bayan Obo mining area as an example,comparing the density changes before and after soaking.It is concluded that the density of rock increases in varying degrees after soaking,except mica-type iron ore.For rocks(ores)with developed pores or fissures,the percentage of density difference after soaking is greater than 0.5%,and the density difference percentage will be greater than 0.5%.However,for the rock(ore)with dense structure,the influence of soaking on the density measurement is less than 2 times of the measurement error,which is negligible.