CN-121978197-A - Method for measuring total content of impurity elements in natural high-purity quartz mineral

CN121978197ACN 121978197 ACN121978197 ACN 121978197ACN-121978197-A

Abstract

The invention relates to a method for measuring total impurity elements of natural high-purity quartz minerals, which is characterized in that a laser sheet of the quartz minerals is prepared, a polarization microscope is utilized for observation and photographing, an analysis test point is designed on a photo, and point-by-point analysis measurement is carried out on laser ablation and inductively coupled plasma spectra according to the design point, so that the accurate measurement of the impurity elements of the quartz minerals in the natural high-purity quartz raw materials is realized, comprehensive analysis and evaluation are carried out, and the grade characteristics of the quartz minerals in the high-purity quartz raw materials are further determined. The invention is suitable for analyzing and measuring the impurity elements in the natural quartz minerals, has the advantages of low detection limit, high sensitivity, wide linear range and the like, can be more applied to effective and rapid evaluation, quality monitoring and the like of high-purity quartz raw materials, and provides a quartz mineral raw material with stable grade for the high-purity quartz sand industry.

Inventors

ZHANG YONG
TANG CHUNHUA
ZHONG FUJUN
PAN JIAYONG
YUAN JING
LIU GUOQI
YAN JIE
ZHANG XIA
ZHOU YU

Assignees

东华理工大学
江西有色地质矿产勘查开发院

Dates

Publication Date: 20260505
Application Date: 20231213

Claims (8)

1. The method for measuring the total content of impurity elements in the natural high-purity quartz mineral is characterized by comprising the following measuring steps: S1, positioning and slicing a rock specimen, wherein 3 sheets with thickness T1=30+ -5 μm, T2=80+ -5 μm and T3=150+ -10 μm are prepared, and the sheets are polished on one side; S2, carrying out rock-ore identification and fluid inclusion lithology observation on the T1 sheet by using a polarizing microscope, carrying out quantitative analysis by combining an electronic probe (EMPA) of the T2 sheet, namely a probe sheet, and then circling a T3 sheet, namely a region where quartz minerals in a laser sheet are located and photographing the laser sheet; S3, designing test points for a laser ablation inductively coupled plasma mass spectrometer on a reflected light photo obtained by shooting a view field circled on the T3 sheet, symmetrically arranging equidistant test points with the interval of 88-200 mu m towards the edge of quartz mineral on the photo by taking the center of the quartz mineral as the center, designing the radius of the test points to be 44 mu m, designing the number of the test points to be 5-12, and uniformly distributing the designed test points with quartz mineral particles on the photo; S4, placing the T3 sheet into a sample bin of a laser ablation inductively coupled plasma mass spectrometer for testing, S5, processing test data of the quartz mineral LA-ICP-MS, and outputting a report; S6, the output report is further processed to obtain trace element contents, wherein the contents of B and P elements are corrected by dividing by 100, and Ca is corrected by dividing by 10; S7, calculating the total amount of thirteen elements or IOTA fifteen elements (mug/g) in GB/T32649-2016 high-purity quartz sand for photovoltaic respectively according to the corrected content data, and determining the total amount of quartz mineral impurity elements.
2. The method for measuring total impurity elements of natural high-purity quartz minerals according to claim 1, wherein S2 is characterized in that a T3 sheet, namely an area where quartz minerals in a laser sheet are located, is circled and the laser sheet is photographed, wherein the photographing requires that an objective lens of a polarizing microscope is 10 times, and reflected light of the same viewing area and orthogonal polarized light photographs are photographed one by one.
3. The method for measuring the total amount of impurity elements in the natural high-purity quartz minerals according to claim 1, wherein the distribution form of the design measuring points is in a shape of a Chinese character 'yi', a Chinese character 'ren' or a Chinese character 'Y', and a Chinese character 'ten' or a Chinese character 'x'.
4. The method for measuring total content of impurity elements in natural high-purity quartz minerals according to claim 1, wherein the test instrument S4 is a GeoLasHD 193nm laser ablation system and an Agilent 7900ICP-MS inductively coupled plasma mass spectrometer, the laser energy is 9+ -2J/cm < 2 >, the laser frequency is 4+ -2 Hz, and the laser beam spot diameter is 44 μm.
5. The method for determining total content of impurity elements in natural high-purity quartz minerals according to claim 1, wherein the LA-ICP-MS test data processing of S5 adopts software ICPMSDATACAL 11.0.0, and uses glass standard substance NISTRAM 610 as external standard to correct trace elements.
6. The method for determining total impurity elements of natural high-purity quartz minerals is characterized in that the method for observing and identifying quartz minerals and intergrowth minerals thereof is characterized in that a single polarization, orthogonal and reflected light of a polarization microscope is used for observing T1 thin plates under the magnification of 25-500 times by switching objective lenses with different multiples, the characteristics of the quartz minerals are determined according to the optical mineralogy characteristics, the structure and the generation relationship of the quartz and the intergrowth minerals thereof are further determined, T3 probe plates are replaced, the melting and fluid inclusion characteristics of the quartz minerals are observed under the magnification of 25-500 times, and the distribution characteristics of the quartz minerals are qualitatively determined, such as that the natural quartz minerals have very many fluid inclusions, the interval between the dispersed inclusions is smaller than 100 mu m and small (1-10 mu m), and further LA-ICP-MS analysis is not needed.
7. The method for determining total impurity elements in natural high purity quartz minerals according to claim 5, wherein the mineral intergrowth with quartz minerals in the T2 sheet is determined by electron probe observation, and the element content of the mineral is quantitatively determined.
8. The method for measuring total impurity elements in natural high purity quartz minerals according to claim, wherein the standard sample used in the S4 measurement is NISTRAM 610:610, and NISTRAM 612:612 and NISTRAM 614:614 are used as monitoring samples. The fifth step of measurement is performed by sequentially measuring standard and sample, testing a group of standard samples (NISTRAM 610, NISTRAM 612 and NISTRAM) before testing the sample, then after 10 measurement points are analyzed for each test, and after testing 1 group of standard samples, starting the subsequent sample point analysis test, wherein each point test period is 90 seconds, the first 20 seconds is a prepared measurement point period, laser ablation is performed at 20 seconds, the duration is 40 seconds, helium is continuously flushed in the whole process, and the ICP-MS continuously receives and records the count values of elements (Li, be, B, na, mg, al, P, K, ca, sc, ti, cr, mn, fe, ni, cu, zn, ge, rb, zr, sn, ba, W, tl, bi, U, si) and the like. The first 20 seconds is the background integration interval and the second 40 seconds is selected to be 25 as the test integration interval. And processing the counting signal file of the ICP-MS by ICPMSDATACAL 11.0.0 software, calculating the element content by adopting a multi-external standard and non-internal standard method, namely a total normalization method, selecting Si of NISTRAM 610 standard samples as normalization elements to eliminate the influence of laser ablation amount change on sensitivity drift, deriving the measured content values of the elements, correcting part of the elements according to multiples, and finally obtaining an analysis test result.

Description

Method for measuring total content of impurity elements in natural high-purity quartz mineral Technical Field According to the method for measuring the total content of impurity elements in the natural high-purity quartz mineral, a sample is obtained through in-situ micro-area ablation of a laser ablation system, and is sent into a plasma mass spectrum for analysis and determination of the element content, and the grade of quartz mineral raw materials is comprehensively evaluated by combining microscopic lithology observation of inclusion bodies of a test quartz mineral fluid. Background The LA-ICP-MS in-situ micro-area analysis and test technology has wide application, and can be used in various fields and industries such as materialology, mineralogy, mineral deposit science, isotope chronology and the like. In the field of materiallogy, LA-ICP-MS in-situ micro-area analysis and test technology acquires material micro-area element distribution characteristics. The trace element content characteristics of the growth zone of minerals are analyzed in the mineralogy field. The characteristics of occurrence state of the mineral elements and the like are obtained in the field of ore deposit science. In the field of isotope chronology, information such as the isotope year of earth, merle and extraterrestrial rock samples is acquired. GB/T32649-2016 high-purity quartz sand for photovoltaic use the total content of impurity elements of high-purity quartz sand for photovoltaic use should be less than or equal to 25 mug/g, wherein the total content of potassium, lithium and sodium is less than 2.5 mug/g, and the content of each impurity element should meet the regulation of Table 1. Table 1 the content of each impurity element was expressed in micrograms per gram (. Mu.g/g) Impurity elementAllowable contentAluminum (Al)<20Calcium (Ca)<1Iron (Fe)<0.5Sodium (Na)<1Potassium (K)<1Lithium (Li)<1Magnesium (Mg)<0.5Cadmium (Cr)<0.1Nickel (Ni)<0.1Boron (B)<0.1Manganese (Mn)<0.2Copper (Cu)<0.1Titanium (Ti)<1.5 The particle size of the high-purity quartz sand for photovoltaic is in the range of 70-350 mu m, and the cumulative mass fraction in the particle size range is more than or equal to 90%. The cumulative mass fraction of particles smaller than 100 μm or larger than 300 μm should be smaller than 1%. The measurement of the high-purity quartz sand has a corresponding recommended test method, namely, the measurement is carried out through ICP-MS inductively coupled plasma spectrometry, but the method is not effective as a raw material of the high-purity quartz sand, namely, the measurement of the impurity element content of natural quartz minerals, which prevents the mineral exploration breakthrough of a high-purity quartz raw material deposit and further prevents the mineral exploration and evaluation of the high-purity quartz mineral raw material. An effective and rapid method for measuring and comprehensively evaluating impurity elements of high-purity quartz minerals. Therefore, developing a technique that is accurate, efficient and suitable for the analytical testing work of lithium, boron, sodium, magnesium, aluminum, phosphorus, potassium, calcium, scandium, titanium, cadmium, manganese, iron, nickel, copper, zinc, germanium, rubidium, zirconium, tin, barium, tungsten, thallium, bismuth, uranium in natural massive quartz minerals has become a urgent problem for analytical and evaluation workers today. Disclosure of Invention The invention aims at developing an analysis method for determining lithium, boron, sodium, magnesium, aluminum, phosphorus, potassium, calcium, scandium, titanium, cadmium, manganese, iron, nickel, copper, zinc, germanium, rubidium, zirconium, tin, barium, tungsten, thallium, bismuth and uranium in a natural massive quartz mineral, the method comprises the steps of preparing a laser sheet of quartz minerals, observing and photographing by using a polarizing microscope, designing analysis test points on the photographs, carrying out point-by-point analysis and determination on laser ablation and inductively coupled plasma spectra according to the design points, so as to accurately determine impurity elements of the quartz minerals in natural high-purity quartz raw materials, comprehensively analyze and evaluate, and further determine the grade characteristics of the quartz minerals in the high-purity quartz raw materials. The invention aims to realize the aim, and the specific method is that the method for measuring the total content of impurity elements in natural high-purity quartz minerals comprises the following measuring steps: S1, positioning and slicing a rock specimen, wherein 3 sheets with thickness T1=30+ -5 μm, T2=80+ -5 μm and T3=150+ -10 μm are prepared, and the sheets are polished on one side; S2, carrying out rock-ore identification and fluid inclusion lithology observation on the T1 sheet by using a polarizing microscope, carrying out quantitative analysis by combining an electronic