Method for determining age of titanium-uranium ore by utilizing electronic probe chemical analysis

Abstract

The invention belongs to the technical field of radioactivity measurement of mineralization age, and particularly relates to a method for measuring the age of titanium-uranium ore by using electronicprobe chemical analysis. The method comprises the following steps: step 1, performing typical sample collection; step 2, performing experimental pretreatment, including light sheet preparation, observation under a microscope and conductivity treatment; step 3, carrying out chemical analysis by using an electronic probe EPMA; and step 4, performing data arrangement and calculating the age of the titanium-uranium ore. According to the invention, the age of the titanium-uranium ore is determined by using an electronic probe analysis method, and the obtained age is consistent with the age of the U-Pb of the crystalline uranium ore in the ore deposit replacement rock in the embodiment, so that the titanium-uranium ore and the crystalline uranium ore are formed in the same period of uranium mineralization and are closely related to the formation of the replacement rock. The method is of great significance to subsequent uranium deposit research with the titanium uranium ore as the main uranium ore.

Description

technical field [0001] The invention belongs to the technical field of radioactive measurement of ore-forming age, and in particular relates to a method for determining the age of titanium-uranium ore by using electronic probe chemical analysis. Background technique [0002] Ore-forming age is a core issue in the study of ore deposits, which is of great significance for understanding the genesis of ore deposits, establishing metallogenic models and guiding mineral exploration. For a long time, uranium ore dating has always been an important factor restricting the age of uranium ore-forming and studying the regularity of ore-forming. [0003] At present, uranium ore determination methods mainly include the following three categories: (1) radioactive dating using uranium minerals; (2) radioactive dating using uranium ores; Although the workload of sample processing in the early stage is reduced, the sample must satisfy that all minerals are formed at the same time as uranium ...

AI Technical Summary

Problems solved by technology

However, this method has the following disadvantages: (1) The demand for samples is large, and the chemical pretreatment is complex, time-consuming and laborious, and it is likely to return in vain; (2) Destructive analysis, after the sample analysis and testing, cannot be repeated Test verification; (3) When there are multiple age regions in the sample on the microscopic scale or the selected uranium minerals were formed in different periods, the age obtained by the analysis is a mixed age, which has no geological significance

Secondary ion mass spectrometry SIMS method, although the spatial resolution of the instrument is high and the analysis results are accurate, but the experimental equipment is expensive, the test cost is high, there are special requirements for sample preparation, and there is a certain degree of damage to the analysis sample

The LA-ICP-MS method has accurate analysis results, but the spatial resolution is low, it is not suitable for tiny uranium minerals (below 20 μm), and it will seriously damage the sample, so it cannot be verified by repeatable measurement

[0006] The EPMA method has a very high spatial resolution (2-3 μm), simple sample preparation, ordinary light thin slices can be directly analyzed after carbon plating, and the instrument is common, and the test cost is low; but the only disadvantage of this method is the analysis accuracy. Only when the uranium content in the mineral is high (>n%), and the mineral formation time is long (>100Ma), the analysis data can fully meet the dating accuracy requirements

Images