锆石砂矿品位不同测试和计算方法对比——以辽东湾海域为例

Different calculation methods of zircon placer deposit grades in the Liaodong Bay area

  • 摘要: 重砂鉴定法与化学分析法是计算滨海金属砂矿地质品位的两种常用方法,然而其计算结果往往存在显著差异,易导致勘查风险,影响我国滨浅海锆、钛等关键金属资源的开发利用。本文以辽东湾海域采集的表层和柱状样品为基础,通过重矿物鉴定、化学分析和粒度分析,采用两种方法换算锆石品位并进行比较。结果表明,重砂鉴定法换算的锆石品位值域范围较小、平均值较低但变异系数较大,且两种方法高值点的空间分布相关性较弱。分析认为,这种差异主要源于样品选取、假设前提和应用条件的不同。重砂鉴定法存在鉴定粒度范围受限导致的粒度代表性问题、现有计算公式假设误差问题,以及计算公式参数交互效应引发的品位变异增大问题;化学分析法则面临细粒级锆石无法利用的问题、参数运用错误或缺失的问题,以及轻矿物中赋存Zr元素带来的高本底值和误差问题。为提升换算结果的可靠性,建议根据具体目标有针对性地选取测试与计算方法,结合多种分析手段进行结果验证,同时引入新技术与更完善的模型,以优化滨海金属砂矿勘查的精度与效率。

     

    Abstract: Heavy mineral identification and chemical analysis are two commonly used methods for calculating the geological grades of coastal metallic placer deposits. However, significant discrepancies often exist between the results obtained from the two methods, leading to exploration risks and hindering the development and utilization of critical metal resources such as zirconium and titanium in China's coastal and shallow marine areas. Using the surface and core samples collected in the Liaodong Bay offshore area, we conducted heavy mineral identification, chemical analysis, and grain-size analysis, from which the zirconium grades were calculated using the two methods and the results were compared. Results show that the zirconium grades calculated by the heavy mineral identification had a narrower range and lower average values but a higher coefficient of variation than those of chemical analysis. Additionally, the spatial distribution correlation of high-grade points between the two methods was weak. We believed that the discrepancies were due mainly to the differences in sample selection, preconditions and assumptions, and application conditions. Specifically, the heavy mineral identification is limited by grain-size ranges, calculation errors due to different presumptions, and increased grade variability caused by parameter interactions. On the other hand, the chemical analysis method faces several other problems, namely, the unavailability of fine-grained zircon, incorrect or missing analysis parameters, and high background values and errors caused by the presence of zirconium in light minerals. To enhance the reliability of the conversion results between the two methods, we recommend selecting testing and calculation methods based on specific objectives, combining multiple analytical approaches to verify the results, and introducing new technologies and improved models to optimize the accuracy and efficiency of coastal metallic placer deposit exploration.

     

/

返回文章
返回