阅读说明：本技术 一种保持数据准确性的野外pxrf岩心测试方法 (Open-air PXRF core testing method capable of keeping data accuracy ) 是由 张明明 周国玉 王成宝 李思洋 焦峻嵚 龙瑾潇 陈静 范裕 于 2020-12-10 设计创作，主要内容包括：本发明公开了一种保持数据准确性的野外PXRF岩心测试方法,对研究区岩心样品长度进行加权平均统计分析,确定岩心组合样长以及每段岩心的深度；保持岩心表面干燥清洁；设置PXRF仪器为地球化学测试模式,每个点测试时间为60秒；以研究区内一定数量的岩心样品实验室数据为标准来对PXRF仪器进行校准,得到每个元素的校准系数,保证后续测试数据精度；在每个组合样长内多点测试然后取其平均值作为最后测试结果。本发明在研究区组合样长内多点测试然后取其平均值作为最后测试结果,可以大大提高测试数据的精度,获得的结果可媲美实验室测试数据,满足野外大规模岩心地球化学数据的采集,促进区域的找矿勘查和资源储量评估。(The invention discloses a field PXRF core test method for maintaining data accuracy, which is characterized in that weighted average statistical analysis is carried out on the core sample length of a research area, and the combined sample length of a core and the depth of each section of the core are determined; keeping the surface of the rock core dry and clean; setting a PXRF instrument as a geochemical test mode, wherein each point test time is 60 seconds; calibrating the PXRF instrument by taking a certain amount of core sample laboratory data in a research area as a standard to obtain a calibration coefficient of each element and ensure the accuracy of subsequent test data; the test is performed at multiple points within each combined sample length and then the average value is taken as the final test result. The invention tests the combination sample length in the research area at multiple points and then takes the average value as the final test result, which can greatly improve the precision of the test data, the obtained result can be comparable with the laboratory test data, the acquisition of the field large-scale core geochemical data is satisfied, and the regional prospecting survey and the resource reserve evaluation are promoted.)

1. A field PXRF core test method for maintaining data accuracy is characterized by comprising the following steps: the method specifically comprises the following steps:

(1) carrying out weighted average statistical analysis on the lengths of the core samples in the research area, and determining the combined sample length of the core and the depth of each section of the core;

(2) setting a PXRF instrument as a geochemical test mode, wherein the test time of each point is 60 seconds;

(3) calibrating a PXRF instrument by taking a certain amount of core sample laboratory data in a research area as a standard to obtain a calibration coefficient of each element;

(4) and testing at multiple points in the length of the core combined sample, and then taking the average value of the test points as the final test result.

2. The field PXRF core testing method for maintaining data accuracy as claimed in claim 1, characterized in that: the PXRF instrument calibration method specifically comprises the following steps: collecting a certain number of rock core samples in a research area as standard samples, wherein the standard samples need to belong to different strata and cover different lithologies in the rock core of the borehole, carrying out laboratory whole-rock main trace element test on the standard samples, then carrying out correlation scattering point projection on element data of PXRF test standard samples and laboratory data, taking the laboratory data of each element as a longitudinal axis (y) and the PXRF data as a transverse axis (x), obtaining a variable equation of y relative to x, and calibrating the test element value of each point of PXRF by taking the variable equation as a calibration equation.

3. The field PXRF core testing method for maintaining data accuracy as claimed in claim 1, characterized in that: selecting a core with the depth of a research area of M meters as a test object, taking every N meters as a core combined sample length, numbering the core depth in the M meters according to the unit of every N meters, counting M/N sections, taking multiple points in each section of core to perform PXRF test, and taking the average value of the multiple points in each section of core after the multiple points are tested as the content of each element of the section of core.

Technical Field

The invention relates to the technical field of acquisition and analysis of geochemical data of rocks, in particular to a field PXRF core testing method for keeping data accuracy.

Background

The extraction of the combination characteristics of the geochemical elements and the geochemical abnormal delineation have important significance for the prospecting of mines, and the rapid analysis of the element components and the content thereof in rock samples to judge the mineralization potential of a research area is a very key problem. The traditional laboratory physical and chemical analysis method is generally slow in speed and expensive, and a portable X-ray fluorescence analyzer (PXRF) can quickly, accurately and cheaply analyze target body elements, so that the method is widely applied to analysis of ores, soil, metals and the like. How to ensure the accuracy and effectiveness of field PXRF data acquisition will directly affect the analysis result.

Disclosure of Invention

The invention aims to make up for the defects of the prior art, and provides a field PXRF core testing method for maintaining data accuracy.

The invention is realized by the following technical scheme:

a field PXRF core testing method for maintaining data accuracy specifically comprises the following steps:

(1) carrying out weighted average statistical analysis on the lengths of the core samples in the research area, and determining the combined sample length of the core and the depth of each section of the core;

(2) setting a PXRF instrument as a geochemical test mode, wherein the test time of each point is 60 seconds;

(3) since the data of the PXRF direct test is semi-quantitative data, before large-scale test, a PXRF instrument needs to be calibrated by taking a certain amount of core sample laboratory data (the number of standard samples is determined according to actual conditions) in a research area as a standard to obtain a calibration coefficient of each element;

(4) and testing at multiple points in the length of the core combined sample, and then taking the average value of the test points as the final test result. The surface of the core is kept dry and clean during the test.

The PXRF instrument calibration method specifically comprises the following steps: collecting a certain number of core samples (determined according to actual conditions) in a deposit of a research area as standard samples, wherein the standard samples need to belong to different strata and cover different lithologies in a core of a drilled hole, carrying out laboratory whole-rock main trace element test on the standard samples, then carrying out correlation scattering point projection on element data of a PXRF test standard sample and laboratory data, taking the laboratory data of each element as a longitudinal axis (y) and the PXRF data as a transverse axis (x), obtaining a variable equation of y relative to x, and taking the variable equation as a calibration equation to calibrate the test element value of each point of PXRF.

The depth of a test object of the multipoint test is M meters, the combined sample length is numbered according to every N meters (the combined sample length is different in different mining areas and needs to be determined according to the actual condition of a research area), M/N sections are counted, multiple points (determined according to the actual condition of the research area) are taken from each section of the core to perform PXRF test, the average value of the tested multiple points of each section is used as the content of each element of the core, and each point is tested for 60 seconds.

The invention has the advantages that: the invention tests at multiple points in a certain core length range-combined sample length (determined according to actual conditions) and then takes the average value as the final test result, thus greatly improving the precision of the test data, obtaining the result which can be comparable with the laboratory test data and meeting the requirement of the acquisition of the field large-scale core geochemical data.

Drawings

FIG. 1 is a scattergram of Cu, S, Fe, W calibration correlations.

FIG. 2 is a graphical representation of correlation of PXRF data for Cu, S, Fe, W elements with laboratory data.

FIG. 3 is a graph of PXRF data of Cu, S, Fe, W elements and laboratory data trend.

Detailed Description

A field PXRF core testing method for maintaining data accuracy specifically comprises the following steps:

(1) carrying out weighted average statistical analysis on the length of the core sample of the mineral deposit in the research area, and determining the combined sample length of the core and the depth of each section of the core;

(2) setting a PXRF instrument as a geochemical test mode, wherein the test time of each point is 60 seconds;

(3) since the data of the PXRF direct test is semi-quantitative data, the PXRF instrument needs to be calibrated by taking a certain amount of core sample laboratory data in a deposit of a research area as a standard before a large-scale test, so that a calibration coefficient of each element is obtained;

(4) and testing at multiple points in the length of the core combined sample, and then taking the average value of the test points as the final test result. The surface of the core is kept dry and clean during the test.

The PXRF instrument calibration method specifically comprises the following steps: the significance of the averaging method for PXRF multi-point testing in the combined sample length in order to guarantee the data accuracy is shown by taking a core number ZK16+02 of a copper-sulfur-tungsten polymetallic ore bed of the buckwheat mountain in Anhui city as a test object. Nine rock core samples are collected in the buckwheat mountain ore deposit to serve as standard samples, the standard samples need to belong to different strata and cover different lithologies in the rock core of the drill hole, and the test standard samples mainly comprise quartz sandstone, skarn type altered ore body, marble and granite spangle. The method comprises the steps of carrying out laboratory full-rock main trace element testing on a standard sample, carrying out correlation scatter plot on element data of a PXRF testing standard sample and laboratory data, taking the laboratory data of each element as a longitudinal axis (y) and the PXRF data as a transverse axis (x), obtaining a variable equation of y relative to x, and taking the variable equation as a calibration equation to calibrate the testing element value of each point of the PXRF.

The test object of the multipoint test is a buckwheat mountain deposit ZK16+02 rock core, the test depth is 37 m-103 m, the test object is numbered according to the combined sample length of every 1.5m, 40 sections are counted, five points are taken from each section of the rock core for PXRF test, the average value of the five-point tested value of each section is used as the content of each element of the rock core, and each point is tested for 60 seconds.

Example (b): as the direct test value of the PXRF instrument is a semi-quantitative result, data calibration is needed, and the test area is a buckwheat hill copper sulfide deposit in Anhui Xuancheng. Nine rock core samples are collected in the buckwheat mountain ore deposit to serve as standard samples, the nine sample standard samples belong to different strata and cover different lithologies in the ore deposit to ensure the calibration precision, and the standard samples mainly comprise quartz sandstone, skarn type altered ore body, marble and granite spangle. The method comprises the steps of carrying out laboratory full-rock main trace element testing on a standard sample, carrying out correlation scatter plot on element data of a PXRF testing standard sample and laboratory data, taking the laboratory data of each element as a longitudinal axis (y) and the PXRF data as a transverse axis (x), obtaining a variable equation of y relative to x, and taking the variable equation as a calibration equation to calibrate the testing element value of the PXRF. The buckwheat mountain ore deposit belongs to a skarn type hydrothermal solution filling ore deposit, main minerals are chalcopyrite, pyrite and scheelite, and mineral forming elements are Cu, S, Fe and W, so the four elements are mainly calibrated. The calibration equations are respectively: cu: y is 1.4611 x-0.0089; s: 2.0323 x-0.6253; fe: y 0.9744x + 1.8436; w: y 0.4587x +0.0029.

A scatter plot of the Cu, S, Fe, W calibration correlation is shown in FIG. 1.

Results of the experiment

The core tested at this time is a buckwheat mountain copper sulfur deposit core ZK16+02, the test depth is 37 m-103 m, the combined sample length is 1.5m, each 1.5m is numbered as one section, and the total number is 40 sections, as shown in Table 1.

TABLE 1 ZK16+02 test core Numbers

And taking five points in each section of the combined sample long core for PXRF test, and taking the average value of each section of the five-point test as the element content of the section of the core. The core PXRF test values are plotted against the laboratory test data results, as shown in fig. 2 and 3.

As can be seen from fig. 2, the correlation between the five-point PXRF test average value of the four mineral forming elements of Cu, S, Fe and W in each combined sample length of the buckwheat hill copper sulfide deposit ZK16+02 core and laboratory data is good, the two results show obvious positive correlation, the correlation coefficient is above 0.9, and fig. 3 shows that the two test results have consistent variation trends and can reflect the peak value variation of the elements.

Conclusion

The PXRF field core multipoint test averaging technical method can greatly improve the accuracy of test data, meet the requirement of collecting field large-scale core geochemical data and promote regional prospecting exploration.