A semi-quantitative analysis method for mineral content in debris flow samples

Abstract

The present invention belongs to the field of material analysis methods, and particularly relates to a semi - quantitative analysis method for the mineral content in debris flow samples. The debris flow samples are screened to a size not greater than 0.075 mm, and the screened debris flow samples are subjected to XRD testing and XRF elemental analysis; the diffraction peaks obtained from the XRD testing are matched according to the X - ray diffraction standard cards, and the minerals corresponding to the XRF elements are selected, and then the types of minerals in the debris flow are determined according to the matching degree of the elements and the diffraction angles; based on the chemical formulas of the mineral types determined in step S2 and the XRF data, the relative contents of each mineral are calculated; the relative contents of the obtained minerals are normalized, and finally the relative proportions of each mineral are obtained. The measurement method of the present invention is simple, the calculation is simple and efficient, and it can quickly and accurately perform semi - quantitative analysis on the mineral content in debris flow samples, especially suitable for complex debris flows, laying a foundation for the study of the formation mechanism of debris flows.

Description

Technical Field

[0001] The present invention belongs to the field of material analysis methods, and particularly relates to a semi-quantitative analysis method for mineral content in debris flow samples. Background Art

[0002] In the Hengduan Mountains area, geological movements are active, so earthquakes occur frequently. Along with the unique terrain, debris flows are extremely likely to be triggered, causing serious economic losses and having a wide range of impacts and huge losses. Regarding the triggering mechanism of debris flows, Zhao Yong (Zhao Yong, Guilin University of Technology, 2020, 24 - 25.) believes that the formation of debris flows is closely related to the mineral and chemical compositions of the parent rock; Gai Jie (Gai Jie, Jilin University, 2018, 25 - 26.) also studied the clay minerals and their distribution characteristics in the Niqiuhe fault gouge in the Inner Mongolia Dayangshu Basin and speculated on the earthquake activity mechanism in this area based on this. Given the predictability of mineral composition and distribution for geological activities and the occurrence of debris flows, it is crucial to determine the quantitative analysis of minerals in debris flows.

[0003] At present, there are several methods for quantitative analysis of mineral content: chemical element method, optical microscope analysis method, near-infrared spectroscopy analysis method, X-ray diffraction analysis method, and X-ray fluorescence-X-ray diffraction combined analysis method. Chu Yang (Chu Yang, Modern Salt Chemical Industry, 2021, 65-66.) effectively converted the percentage content of elements in the shale gas reservoir into the content of mineral components in the reservoir by using the chemical element method, but it is difficult to distinguish minerals with the same elemental composition or extensive isomorphic substitution. Wang Hangming (Wang Hangming, Physical Testing and Chemical Analysis Part A: Physical Testing, 2015, 51(05): 332-336.) observed the proportion of various mineral phases through an optical microscope. However, the microscopic observation is not only restricted by sample preparation, and multiple directions need to be tested before identification and calculation, which reduces the efficiency; moreover, small-particle-size minerals are also difficult to distinguish under the microscope and need to be combined with TEM means; and minerals with the same morphology are also difficult to distinguish under the microscope, resulting in low data reliability and accuracy. In order to improve the efficiency and accuracy of sample identification work, Hong Dafeng (Hong Dafeng, Enterprise Technology Development, 2014, 33(01): 42-44.) used near-infrared spectroscopy to mathematically predict the mineral phases in natural rocks. However, this method needs to be combined with standard samples to establish a regression linear model to predict the mineral content. Due to the scattered distribution of the true values of the mineral content, the error between the mineral content predicted by the linear regression model and the true mineral content is large, and the accuracy is low. Pu Haibo (Pu Haibo, Journal of Investigation Science and Technology, 2011, (05): 12-14) used the corresponding relationship between the characteristic peak value of X-ray diffraction and the clay mineral content to quantitatively analyze clay minerals. It is necessary to solve the mineral content according to the diffraction angle, RIR coefficient, diffraction intensity, and peak area. Among them, RIR is affected by particle size, origin, etc., and there are inaccuracies and non-uniqueness, and the RIR values of some minerals in the standard card are missing; in addition, the intensity of the diffraction peak is affected by orientation, etc., and there is a situation where it does not match the intensity shown in the PDF card; furthermore, the high carbonate content in natural samples will reduce the accuracy of measuring the diffraction intensity of other clay minerals. Therefore, it is necessary to use NaAc buffer solution (pH = 4.8-5.2) to remove the carbonate in the sample to eliminate the influence, which not only makes the operation complex but also introduces new elements, reducing the accuracy of the analysis method. Therefore, the traditional diffraction method is only used for the quantitative analysis of samples with less than 4 types of phases. Zeng Ze (Zeng Ze, Journal of Inspection and Quarantine, 2012, 22(06): 4-6, 36) et al. applied XRF-XRD to analyze magnesite, chlorite, quartz, and talc and other symbiotic mixed minerals, and used the coefficient matrix to calculate the chemical formula structure of the mixed minerals with clear clarity. However, the calculation results may have infinite solutions or no solutions and are not applicable to complex mixtures. Debris flow is a natural complex mixed mineral (containing carbonate, quartz, clay minerals, etc.). Some minerals in the mixture have the same morphology, contain organic matter in their chemical composition, and have isomorphic substitution in their mineral structures. Therefore, existing methods are difficult to be applicable to the semi-quantitative analysis of minerals in complex debris flow samples. Summary of the Invention

[0004] The object of the present invention is to overcome the shortcomings of the prior art and provide a semi - quantitative analysis method for the mineral content in debris flow samples.

[0005] The object of the present invention is achieved by the following technical solutions: A semi - quantitative analysis method for the mineral content in debris flow samples, comprising the following steps:

[0006] S1. Screen the debris flow sample to not more than 0.075 mm, and conduct XRD tests on the screened debris flow sample; conduct XRF elemental analysis on the screened debris flow sample after drying and ablation;

[0007] S2. Match the diffraction peaks obtained from the XRD test according to the X - ray diffraction standard cards, select the minerals corresponding to the XRF elements, and then determine the types of minerals in the debris flow based on the matching degree of the elements and diffraction angles, combined with the lithology and mineral characteristics of the sampling site;

[0008] S3. Calculate the relative content of each mineral based on the chemical formula of the mineral type determined in step S2 and the XRF data;

[0009] When selecting the minerals that match the elements in XRF one - to - one, substitute them into formula (1) to calculate the relative content of the mineral; the formula (1) is:

[0010]

[0011] In formula (1), B1O v represents the oxide corresponding to element B; B1O v % represents the percentage content of this oxide in the XRF result; M B1Ov represents the molar mass of the oxide corresponding to element B in mineral A; M A represents the molar mass of mineral A; A% represents the percentage content of the mineral containing element B;

[0012] When two or more minerals contain a certain same element, substitute them into formula (2) to solve the relative content of each mineral respectively, and the formula (2) is

[0013]

[0014] In formula (2): A1, A2, A3... A n represent different minerals; A1%, A2%, A3%... A n % represent the percentage contents of different minerals containing element B; M B1Ov (A1), M B1Ov (A2), M B1Ov (A3),... M B1Ov(A n ) represents different minerals A1 - A containing element B n The molar mass of the oxide corresponding to element B in them; represents the molar mass of different minerals; B% represents the percentage content of the oxide of element B in the XRF test pattern;

[0015] S4. Normalize the relative contents of the minerals obtained by calculation in step S3, and finally obtain the relative proportions of the minerals.

[0016] Furthermore, the conditions for drying in step S1 are drying at 105°C for 2 h, and the conditions for ablation are ablation at 900 - 950°C for 2 h.

[0017] Furthermore, when selecting minerals corresponding to XRF elements in step S2, the threshold of element content is set to 0.1%, and when the element content is lower than this value, the element is ignored.

[0018] Furthermore, when matching the diffraction peaks obtained by XRD test according to the X-ray diffraction standard card in step S2, the diffraction peaks with intensity < 300 are discarded.

[0019] Furthermore, when there is isomorphism in the mineral in step S3, first set the substitution ratio of isomorphism, and then calculate the relative contents of the minerals; among them, the range of the isomorphism substitution ratio is: Mg / Fe in chlorite is 1 / 5 - 7 / 3; Al / Si in feldspar is 0 - 1.

[0020] Furthermore, the normalization in step S4 is carried out using formula (3), and the formula (3) is:

[0021] N i = A i / N, i = 1, 2, 3, 4……m (3)

[0022] In the formula, A i represents the percentage content of the corresponding mineral calculated, N1, N2,..., N m represents the relative content of the corresponding mineral after normalization, and N is the total element content, equal to 1 - loss on ignition.

[0023] Furthermore, the debris flow sample is a debris flow sample from the Jinsha River Basin.

[0024] The present invention has the following advantages: The present invention conducts XRF and XRD analyses on debris flow samples, and provides a quick and repetitive method for measuring the relative content of minerals in debris flow based on the analysis results of XRF and XRD. This method can be applied to the quantitative analysis of samples containing more than four types of minerals. The measurement method provided by the present invention is simple, and the calculation is simple and efficient. It can quickly and accurately semi-quantitatively analyze the mineral content in debris flow samples, especially suitable for complex debris flows, laying a foundation for the research on the formation mechanism of debris flows. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 FIG. is a schematic diagram of the XRF element content analysis of debris flow sample 1.

[0026] Figure 2 FIG. is a matching diagram of the XRD diffraction pattern of debris flow sample 1.

[0027] Figure 3 FIG. is a diagram of the relative content of minerals in debris flow sample 1.

[0028] Figure 4 FIG. is a standard card diagram of the phase.

[0029] Figure 5 FIG. is a pie chart of Qualification in the standard card of the phase. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The following further describes the present invention in conjunction with the drawings and embodiments. The protection scope of the present invention is not limited to the following:

[0031] Example 1: A semi-quantitative analysis method for the mineral content in a debris flow sample, comprising the following steps:

[0032] S1. Screen the debris flow sample 1 taken from the Jinsha River Basin to less than 0.075 mm, conduct XRD tests on the screened debris flow sample to obtain an XRD diffraction pattern; dry the screened debris flow sample at 105 °C for 2 h and ablate it at 900 °C for 2 h, and then conduct XRF element analysis to obtain the content of each element, as Figure 1 shown;

[0033] S2. Match the diffraction peaks obtained from the XRD test according to the X-ray diffraction standard card, as Figure 2As shown, minerals corresponding to XRF elements are selected. When the element content is lower than this value, the element is ignored. Then, based on the matching degree of the elements and diffraction angles, combined with the lithology and mineral characteristics of the sampling site, the types of minerals in the debris flow are determined to be albite (1 / 2Na2O·1 / 2Al2O3·3SiO2), muscovite (1 / 2K2O·3 / 2Al2O3·3SiO2·H2O), hematite (Fe2O3), and quartz (SiO2); among them, when selecting minerals corresponding to XRF elements, the threshold of the element content is set to 0.1%. When matching the diffraction peaks obtained from XRD tests according to the X-ray diffraction standard cards, the diffraction peaks with intensity < 300 are discarded;

[0034] S3. Based on the chemical formulas of the mineral types determined in step S2 and the XRF data, calculate the relative content of each mineral, as Figure 3 shown;

[0035] When minerals that match the elements in XRF one by one are selected, substitute them into formula (1) to calculate the relative content of the mineral; the formula (1) is:

[0036]

[0037] In formula (1), B1O v represents the oxide corresponding to element B; B1O v % represents the percentage content of this oxide in the XRF result; M B1Ov represents the molar mass of the oxide corresponding to element B in mineral A; M A represents the molar mass of mineral A; A% represents the percentage content of the mineral containing element B;

[0038] When a certain element is contained in two or more minerals, substitute them into formula (2) to solve the relative content of each mineral respectively. The formula (2) is

[0039]

[0040] In formula (2): A1, A2, A3...A n represent different minerals; A1%, A2%, A3%...A n % represent the percentage contents of different minerals containing element B; M B1Ov (A1), M B1Ov (A2), M B1Ov (A3),...M B1Ov (A n ) represent the molar masses of the oxides corresponding to element B in different minerals A1 - A n ; represent the molar masses of different minerals; B% represents the percentage content of the oxide of element B in the XRF test chart;

[0041] The specific calculation is as follows:

[0042] In this sample, albite exists alone with Na element. Let albite be A1, muscovite be A2, hematite be A3, and quartz be A4; A1%, A2%, A3%, A4% represent the mineral percentage contents of albite, muscovite, hematite, and quartz respectively; respectively represent the molar masses of albite, muscovite, hematite, and quartz. respectively represent the molar masses of SiO2, Fe2O3, Al2O3, Al2O3, and Na2O; Na2O%, Fe2O3%, SiO2%, and Al2O3% respectively represent the percentage contents of Na2O, Fe2O3, SiO2, and Al2O3 in XRF; SiO2(A1)%, SiO2(A2)%, and SiO2(A4)% represent the percentage contents of SiO2 in albite, muscovite, and quartz respectively; Al2O3(A1)% and Al2O3(A2)% respectively represent the percentage contents of Al2O3 in albite and muscovite. Substitute into formula (1) to calculate the relative content of albite, the mineral albite Substitute the value Na2O% = 0.96%, and obtain A1% ≈ 8.11%, that is, the relative content of albite is 8.11%.

[0043] Similarly, Substitute the value A1% ≈ 8.11%, and obtain SiO2(A2)% ≈ 5.57% and Al2O3(A3) ≈ 1.58%.

[0044] Similarly, Al2O3(A2)% = Al2O3% - Al2O3(A1)%. Substitute the values Al2O3(A1)% ≈ 1.58% and Al2O3(A2)%

[0045] ≈ 1.58%. Then Al2O3(A2)% = 12.23% - 1.58%, and obtain Al2O3(A2)% = 12.23%.

[0046] Similarly, Substitute the value Al2O3(A2)% = 12.23%, and obtain A2% ≈ 27.70%, that is, the relative content of dolomite is 27.70%.

[0047] Similarly, Substitute the value A2% ≈ 27.70%, It is obtained that SiO2(A2)% ≈ 12.53%.

[0048] Similarly, substituting the value of A3% = Fe2O3%, Fe2O3% = 4.61%, A3% = Fe2O3% = 4.61%, it is obtained that A3% = 4.61%, that is, the relative content of magnetite is 4.61%.

[0049] Similarly, substituting the values into A4% = SiO2(A4)% = SiO2% - SiO2(A1)% - SiO2(A2)%, where SiO2% = 74.11%, SiO2(A1)% = 5.57%, SiO2(A2)% = 12.53%, A4% = SiO2(A4)% = 74.11% - 5.57% - 12.53%, it is obtained that A4% = 56.01%, that is, the relative content of quartz is 56.01%.

[0050] S4. Normalize the relative contents of each mineral obtained by calculation in step S3, and finally obtain the relative proportions of each mineral; the normalization is carried out using formula (3), and the formula (3) is:

[0051] N i = A i / N, i = 1, 2, 3, 4……m (3)

[0052] In the formula, A1, A2, …, A m represent the relative contents of the corresponding minerals calculated, and N1, N2, …, N m represent the relative contents of the corresponding minerals after normalization. N is the total element content, equal to 1 - loss on ignition. The specific calculation is as follows:

[0053] The total element content of XRF is 96.43%, and after normalization, the relative contents of each mineral are: N1% = 8.11% / 96.43% ≈ 8.41%, N2% = 27.70% / 96.43% ≈ 28.72%, N3% = 4.61% / 96.43% ≈ 4.78%, N4% = 56.01% / 96.43% ≈ 58.08%. That is, the content of albite in the debris flow sample is 8.41%, the content of muscovite is 28.72%, the content of hematite is 4.78%, and the content of quartz is 58.08%.

[0054] Example 2: A semi - quantitative analysis method for mineral content in a debris flow sample, including the following steps:

[0055] S1. Screen the debris flow sample 2 to less than 0.075 mm, and conduct XRD tests on the screened debris flow sample; dry the screened debris flow sample at 105 °C for 2 h, and after drying, conduct XRF elemental analysis after ablation at 950 °C for 2 h to obtain the contents of each element;

[0056] S2. Match the diffraction peaks obtained from the XRD test with the X-ray diffraction standard cards, select the minerals corresponding to the XRF elements, and then select according to the matching degree of the elements and the diffraction angle: hematite (Fe2O3), muscovite (H2KAl3(SiO4)3), quartz (SiO2), chlorite ((Mg,Fe)6(Si,Al)4O 10 (OH)8), albite (NaAlSi3O8), calcite (CaCO3); considering the lithology and mineral characteristics of the sampling site, the substitution ratios of magnesium-iron isomorphous and silicon-aluminum isomorphous in chlorite are Mg / Fe = 5 / 1 and Si / Al = 3 / 1 respectively; considering the element valence balance, determine the types of minerals in the debris flow as hematite (Fe2O3), muscovite (1 / 2K2O·3 / 2AI2O3·3SiO2·H2O), quartz (SiO2), albite (1 / 2Na2O·1 / 2Al2O3·3SiO2·H2O), chlorite (5MgO·1 / 2Fe2O3·1 / 2Al2O3·3SiO2·4H2O), calcite (CaO·CO2); among them, when selecting the minerals corresponding to the XRF elements, set the threshold of the element content to 0.1%, and ignore the element when the element content is lower than this value; when matching the diffraction peaks obtained from the XRD test with the X-ray diffraction standard cards, discard the diffraction peaks with intensity < 300;

[0057] S3. Calculate the relative content of each mineral based on the chemical formula of the mineral types determined in step S2 and the XRF data;

[0058] When selecting the minerals that match the elements in the XRF one by one, substitute them into formula (1) to calculate the relative content of the mineral; the formula (1) is:

[0059]

[0060] In formula (1), B1O v represents the oxide corresponding to element B; B1O v % represents the percentage content of this oxide in the XRF result; M B1Ov represents the molar mass of the oxide corresponding to element B in mineral A; M A represents the molar mass of mineral A; A% represents the percentage content of the mineral containing element B;

[0061] When two or more minerals contain a certain same element, substitute them into formula (2) to solve the relative content of each mineral respectively. The formula (2) is

[0062]

[0063] In formula (2): A1, A2, A3... A n represent different minerals; A1%, A2%, A3%... A n % represent the percentage content of different minerals containing a certain element B; M B1Ov (A1), M B1Ov (A2), M B1Ov (A3),... M B1Ov (A n ) represent the molar mass of the oxides corresponding to element B in different minerals A1 - A n ; represent the molar mass of different minerals; B% represents the percentage content of the oxide of a certain element B in the XRF test chart;

[0064] The specific calculation is as follows:

[0065] In this sample, potassium feldspar alone contains element K, chlorite alone contains element Mg, albite alone contains element Na, and calcite alone contains element Ca. Substitute them into formula (1) to calculate the relative content of albite, the relative content of chlorite, the relative content of calcite, and the relative content of muscovite. Let albite be A1, chlorite be A2, hematite be A3, quartz be A4, and muscovite be A5, and calcite be A6; A1%, A2%, A3%, A4%, A5%, A6% represent the mineral content of albite, chlorite, hematite, quartz, muscovite, and calcite; K2O%, Na2O%, Fe2O3%, SiO2%, MgO% represent the content of K2O, Na2O, Fe2O3, SiO2, and MgO in XRF, represent the molar mass of albite, chlorite, hematite, quartz, muscovite, and calcite: M CaO , M 5MgO respectively represent the molar mass of 3SiO2, 1 / 2K2O, 1 / 2Na2O, 1 / 2Fe2O3, CaO, 5MgO; K2O%, Na2O%, Fe2O3%, SiO2%, MgO% represent the content of K2O, Na2O, Fe2O3, SiO2, and MgO in XRF; SiO2(A1)%, SiO2(A2)%, SiO2(A4)%, SiO2(A5)% represent the content of SiO2 in albite, chlorite, quartz, and muscovite; Fe2O3%(A2), Fe2O3%(A3) respectively represent the content of Fe2O3 in chlorite and hematite; Substitute the value Na2O% = 1.24%, and obtain A1% ≈ 10.48%, that is, the relative content of albite is 10.48%.

[0066] Similarly, Substitute the values, A1% ≈ 10.48%, and obtain, SiO2(A1)% ≈ 7.20%.

[0067] Similarly, Substitute the values, MgO% = 3.18%, and obtain, A2% ≈ 9.27%, that is, the relative content of chlorite is 9.27%.

[0068] Similarly Substitute the values, A2% ≈ 4.26%, and obtain, SiO2(A2)% ≈ 2.86%, Fe2O3(A2)% ≈ 1.27%.

[0069] Similarly, Substitute the values, K2O% = 2.72%, and obtain, A5% ≈ 23.03%, that is, the relative content of muscovite is 23.03%.

[0070] Similarly, Substitute the values, A5% ≈ 23.03%, and obtain, SiO2(A5)% ≈ 10.42%.

[0071] Similarly, Substitute the values, CaO% ≈ 3.90%, and obtain, A6% ≈ 6.96%, that is, the relative content of calcite is 6.96%.

[0072] Similarly, Fe2O3(A3)% = Fe2O3% - Fe2O3(A2)%. Substitute the values, Fe2O3% = 6.15%, Fe2O3(A2)% ≈ 1.27%, and obtain Fe2O3(A3)% = 6.15% - 1.27% = 4.88%

[0073] Similarly, A3% = Fe2O3(A3)%. Substitute the values, Fe2O3% = 4.88%, A3% = Fe2O3(A3)% = 4.88%, and obtain, A3% = 4.88%, that is, the relative content of hematite is 4.88%.

[0074] Similarly, A4% = SiO2% - SiO2(A1)% - SiO2(A2)% - SiO2(A5)%. Substitute the values, SiO2% = 60.01%, SiO2(A1)% = 7.20%, SiO2(A2)% = 2.86%, SiO2(A5)% ≈ 10.42%.

[0075] A4% = SiO2(A4)% = 60.01% - 7.20% - 2.86% - 10.42%, it is calculated that A4% = 39.53%, that is, the relative content of quartz is 39.53%.

[0076] S4. Normalize the relative contents of each mineral obtained by calculation in step S3, and finally obtain the relative proportions of each mineral; the normalization is carried out using formula (3), and the formula (3) is:

[0077] N i = A i / N, i = 1, 2, 3, 4……m (3)

[0078] In the formula, A1, A2, …, A m represent the calculated relative contents of the corresponding minerals, and N1, N2, …, N m represent the relative contents of the corresponding minerals after normalization. N is the total element content, equal to 1 - loss on ignition. The specific calculation is as follows:

[0079] The total content of XRF elements is 94.15%, and after normalization, the relative contents of each mineral are: N1% = 10.48% / 94.15% ≈ 11.13%, N2% = 9.27% / 94.15% ≈ 9.85%, N3% = 4.88% / 94.15% ≈ 5.18%, N4% = 39.53% / 94.15% ≈ 41.99%, N5% = 23.03% / 94.15% ≈ 24.46%, N6% = 6.96% / 94.15% ≈ 7.39%. That is, the content of albite in the debris flow sample is 11.13%, the content of hematite is 5.185.18%, the content of quartz is 41.99%, the content of chlorite is 9.85%, the content of muscovite is 24.46%, and the content of calcite is 7.39%.

[0080] Example 3: A semi - quantitative analysis method for the mineral content in a debris flow sample, comprising the following steps:

[0081] S1. Screen the debris flow sample 3 to less than 0.075 mm, and perform XRD tests on the screened debris flow sample; dry the screened debris flow sample at 105 °C for 2 h, and after drying, perform XRF elemental analysis after ablation at 925 °C for 2 h to obtain the contents of each element;

[0082] S2. Match the diffraction peaks obtained from the XRD test against the X-ray diffraction standard cards, select the minerals corresponding to the XRF elements, and then determine the types of minerals in the debris flow as albite (1 / 2Na2O·1 / 2Al2O3·3SiO2), muscovite (1 / 2K2O·3 / 2Al2O3·3SiO2·H2O), calcite (CaO·CO2), and quartz (SiO2) based on the matching degree of the elements and the diffraction angle, combined with the lithology and mineral characteristics of the sampling site; among them, when selecting the minerals corresponding to the XRF elements, set the threshold of the element content to 0.1%, and ignore the element when the element content is lower than this value; when matching the diffraction peaks obtained from the XRD test against the X-ray diffraction standard cards, discard the diffraction peaks with intensity < 300;

[0083] S3. The oxide contents of the corresponding elements in the XRF test are: SiO2 = 61.30%, K2O = 2.61%, Al2O3 = 15.82%, Na2O = 1.15%, CaO = 3.51%. Based on the chemical formulas of the mineral types determined in step S2 and the XRF data, substitute them into formula (1) or formula (2) to calculate the relative contents of each mineral; the results are: albite = 9.72%, calcite = 6.27%, muscovite = 22.10%, quartz = 44.62%;

[0084] S4. The total content of XRF elements is 82.71%. Substitute the relative contents of each mineral calculated in step S3 into formula (3) for normalization, and finally obtain the relative proportions of each mineral; the results are: quartz = 53.95%, albite = 11.75%, muscovite = 26.72%, calcite = 7.58%.

[0085] Example 4: A semi-quantitative analysis method for the mineral content in a debris flow sample, comprising the following steps:

[0086] S1. Screen the debris flow sample 4 to 0.075 mm, conduct an XRD test on the screened debris flow sample to obtain an XRD diffraction pattern; dry the screened debris flow sample at 105 °C for 2 h, and after drying, conduct XRF element analysis after ablation at 920 °C for 2 h to obtain the contents of each element;

[0087] S2. Match the diffraction peaks obtained from the XRD test against the X-ray diffraction standard cards, select the minerals corresponding to the XRF elements, and then select according to the matching degree of the elements and the diffraction angle: hematite (Fe2O3), muscovite (H2KAl3(SiO4)3), dolomite (CaMg(CO3)2), quartz (SiO2), clinochlore ((Mg,Al)6(Si,Al)4O 10(OH)8), albite (NaAlSi3O8). Combining the lithology and mineral characteristics of the sampling site, it can be obtained that the substitution ratios of magnesium-iron isomorphous substitution and silicon-aluminum isomorphous substitution in clinochlore are Mg / Al = 1 / 1 and Si / Al = 3 / 1 respectively. Combining the elemental valence balance, the types of minerals in the debris flow are determined to be hematite (Fe2O3), muscovite (1 / 2K2O·3 / 2AI2O3·3SiO2·H2O), dolomite (MgO·CaO·CO2), quartz (SiO2), clinochlore (3MgO·2AI2O3·3SiO2·4H2O), albite (1 / 2Na2O·1 / 2Al2O3·3SiO2); among them, when selecting minerals corresponding to XRF elements, the threshold of element content is set to 0.1%, and when the element content is lower than this value, the element is ignored; when matching the diffraction peaks obtained by XRD testing according to the X-ray diffraction standard card, the diffraction peaks with intensity < 300 are discarded;

[0088] S3. The oxide contents of the corresponding elements in the XRF test are: K2O = 2.08%, CaO = 3.45%, SiO2 = 65.84%, AI2O3 = 13.69%, MgO = 1.94%, Fe2O3 = 4.26%, Na2O = 0.86%. Based on the chemical formulas of the mineral types determined in step S2 and the XRF data, substitute them into formula (1) or formula (2) to calculate the relative contents of each mineral; the results are: hematite = 4.26%, muscovite = 17.61%, dolomite = 12.15%, quartz = 48.02%, clinochlore = 15.11%, albite = 7.27%;

[0089] S4. The total content of XRF elements is 104.42%. Substitute the relative contents of each mineral obtained by the calculation in step S3 into formula (3) for normalization, and finally obtain the relative proportions of each mineral; the results are: hematite = 4.08%, muscovite = 16.86%, dolomite = 11.64%, quartz = 45.99%, clinochlore = 14.47%, albite = 6.96%.

[0090] Example 5: A semi-quantitative analysis method for the mineral content in a debris flow sample, comprising the following steps:

[0091] S1. Screen the debris flow sample 5 to 0.075 mm, conduct XRD testing on the screened debris flow sample to obtain an XRD diffraction pattern; dry the screened debris flow sample at 105 °C for 2 h, and after drying, ablate it at 920 °C for 2 h and then conduct XRF elemental analysis to obtain the contents of each element;

[0092] S2. Match the diffraction peaks obtained from the XRD test with the X-ray diffraction standard cards, select the minerals corresponding to the XRF elements, and then select according to the matching degree of the elements and the diffraction angle: muscovite (H2KAl3(SiO4)3), hematite (Fe2O3), quartz (SiO2), chlorite ((Mg,Fe)6(Si,Al)4O 10 (OH)8); Combining the lithology and mineral characteristics of the sampling site, it can be obtained that the substitution ratios of magnesium-iron isomorphous and silicon-aluminum isomorphous in chlorite are Mg / Fe = 5 / 1 and Si / Al = 3 / 1 respectively. Combining the element valence balance, determine the types of minerals in the debris flow as quartz (SiO2), chlorite (5MgO·1 / 2Fe2O3·1 / 2Al2O3·3SiO2·4H2O), muscovite (1 / 2K2O·3 / 2Al2O3·3SiO2·H2O), hematite (Fe2O3); Among them, when selecting the minerals corresponding to the XRF elements, the threshold of the element content is set to 0.1%. When the element content is lower than this value, the element is ignored; when matching the diffraction peaks obtained from the XRD test with the X-ray diffraction standard cards, the diffraction peaks with intensity < 300 are discarded;

[0093] S3. The oxide contents of the corresponding elements in the XRF test are: SiO2 = 61.78%, Al2O3 = 18.25%, Fe2O3 = 6.27%, K2O = 2.65%, CaO = 1.64%, MgO = 1.87%. Based on the chemical formulas of the mineral types determined in step S2 and the XRF data, substitute them into formula (1) or formula (2) to calculate the relative contents of each mineral; The results are: quartz = 49.95%, chlorite = 5.74%, muscovite = 22.44%, hematite = 5.52%;

[0094] S4. The total content of XRF elements is 83.65%. Substitute the relative contents of each mineral obtained by the calculation in step S3 into formula (3) for normalization, and finally obtain the relative proportions of each mineral; The results are: quartz = 59.71%, chlorite = 6.86%, muscovite = 26.83%, hematite = 6.60%.

[0095] In the process of quantitative calculation of the minerals described in the present invention, the experimental formula of the mineral is composed of the oxides of the corresponding elements, and the molar mass of the mineral is calculated according to its crystal chemical formula, and the molar mass is reserved to an integer decimal place.

[0096] In the selection and calculation process of the present invention, it should be noted that the selected samples should be consistent with the calculation results, the elements not contained in the minerals should be discarded during the calculation, and the calculation results are all reserved to two decimal places.

[0097] Comparative Example 1:

[0098] S1. Screen the debris flow sample 1 to less than 0.075 mm, conduct XRD tests on the screened debris flow sample to obtain XRD diffraction patterns; dry the screened debris flow sample at 105 °C for 2 h and ablate it at 900 °C for 2 h, then conduct XRF elemental analysis to obtain the contents of various elements, as Figure 1 shown;

[0099] S2. Match the diffraction peaks obtained from the XRD test according to the X-ray diffraction standard cards, as Figure 2 shown, and select the minerals corresponding to the XRF elements. When the element content is lower than this value, ignore the element. Then, based on the matching degree of the elements and diffraction angles, combined with the lithology and mineral characteristics of the sampling site, determine that the types of minerals in the debris flow are albite (1 / 2Na2O·1 / 2Al2O3·3SiO2), muscovite (1 / 2K2O·3 / 2Al2O3·3SiO2·H2O), hematite (Fe2O3) and quartz (SiO2);

[0100] S3. When solving using the herron coefficient matrix formula, the coefficient of hematite is missing, and the content of the corresponding minerals cannot be calculated.

[0101] For sample 1, in Comparative Example 1, when using the coefficient matrix to find the corresponding coefficient of the mineral lacking hematite, the mineral content cannot be solved. At this time, it is necessary to re-analyze the lithology to obtain the matrix coefficient, which increases the analysis process and reduces the convenience. Using this method, the albite content in the sample can be calculated as 8.41%, the muscovite content as 28.72%, the hematite content as 4.78%, and the quartz content as 58.08%. On the premise of retaining two decimal places in the calculation process, the total mineral content is 99.98%, which is highly close to 100%, with a low error value and reliable data. Compared with Comparative Example 1 in sample processing, the method of the present invention does not need to establish a standard sample and re-measure the core to obtain a new proportional coefficient and calculate the mineral content, making the quantitative analysis of minerals fast and efficient.

[0102] Comparative Example 2:

[0103] S1. Screen the debris flow sample 1 to less than 0.075 mm, conduct XRD tests on the screened debris flow sample to obtain XRD diffraction patterns; dry the screened debris flow sample at 105 °C for 2 h and ablate it at 900 °C for 2 h, then conduct XRF elemental analysis to obtain the contents of various elements, as Figure 1 shown;

[0104] S2. Match the diffraction peaks obtained from the XRD test according to the X-ray diffraction standard cards, as Figure 2As shown, minerals corresponding to XRF elements are selected, and elements with contents lower than this value are ignored. Then, based on the matching degree of the elements and diffraction angles, combined with the lithology and mineral characteristics of the sampling site, the types of minerals in the debris flow are determined to be albite (1 / 2Na2O·1 / 2Al2O3·3SiO2), muscovite (1 / 2K2O·3 / 2Al2O3·3SiO2·H2O), hematite (Fe2O3), and quartz (SiO2).

[0105] S3. On the basis of determining the mineral standard cards, observe the RIR values. For standard cards without RIR data, they need to be replaced with different standard cards of the same phase containing RIR data. We get RIR albite = 2.10, RIR muscovite = 0.36, RIR hematite = 2.40, and RIR quartz = 3.41.

[0106] S4. According to the RIR data, as Figure 4 shown, combined with the Xpert highscore software, after clicking Pattern list in the selected phase standard cards, find the contents of each mineral calculated by RIR in semiquant: the content of albite is 6.00%, the content of muscovite is 31.00%, the content of hematite is 1.00%, and the content of quartz is 61.00%.

[0107] S5. In the selected phase standard cards, click Qualification, find the pie chart of the RIR semiquantitative analysis results, as well as the phases and the proportion of each phase shown in the pie chart, that is, the proportion of each mineral after normalization; from Figure 5 the phases and the proportion of each phase shown, we can get: the content of albite is 6.10%, the content of muscovite is 31.30%, the content of hematite is 1.00%, and the content of quartz is 61.60%.

[0108] For Sample 1, in Comparative Example 2, the RIR semiquantitative analysis is used to calculate the sample, with the content of albite being 6.10%, the content of muscovite being 31.30%, the content of hematite being 1.00%, and the content of quartz being 61.60%; while using the method of the present invention, the content of albite in the sample can be calculated to be 8.41%, the content of muscovite to be 28.72%, the content of hematite to be 4.78%, and the content of quartz to be 58.08%. When using SiO2 or other elemental oxides for error analysis, since one element coexists in multiple minerals, it is not easy for the comparative example to directly calculate the content of oxides with complex elemental occurrence states using mineral contents. And since there is a one-to-one correspondence between hematite and Fe2O3, and the content of hematite is equal to the content of Fe2O3, the content of Fe2O3 in hematite can be directly used for error analysis with the content of Fe2O3 in XRF.

[0109] The Fe2O3 content in XRF is 4.61%, the Fe2O3 content calculated by RIR is 1.00%, and the Fe2O3 content calculated by this method is 4.78%. The Fe2O3 content calculated by RIR and the Fe2O3 content calculated by the method of the present invention are respectively compared with the Fe2O3 content in XRF to make an error analysis: the error value calculated by RIR for sample 1 is 3.61%, and the error value calculated by the method of the present invention for sample 1 is 0.17%. Obviously, 3.61% > 0.17%. The error calculated by RIR semi-quantitative analysis is much larger than the error calculated by this method. Moreover, when the calculated value of the RIR semi-quantitative analysis method is retained, it is only accurate to one decimal place, while the calculated value of the method of the present invention is accurate to two decimal places when retained, and the error value of the obtained result is smaller, more accurate, and more reliable. At the same time, when performing RIR semi-quantitative calculation, in the case of determining the standard card, there is no RIR data in some standard cards, and it is necessary to replace them with different standard cards of the same phase containing RIR data before semi-quantitative analysis calculation can be carried out. However, the method of the present invention does not require determining the RIR value and can be calculated after determining the standard card, which reflects the rapidity of the method of the present invention.

[0110] As described above, it is only the preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and all are covered by the protection scope of the present invention.

Claims

1. A semi - quantitative analysis method for the mineral content in debris flow samples, characterized in that, It includes the following steps: S1. Screen the debris flow sample to no more than 0.075 mm, and conduct XRD tests on the screened debris flow sample; conduct XRF elemental analysis on the screened debris flow sample after drying and ablation; S2. Match the diffraction peaks obtained from the XRD test according to the X-ray diffraction standard cards, select the minerals corresponding to the XRF elements, and then determine the types of minerals in the debris flow based on the matching degree of the elements and diffraction angles, combined with the lithology and mineral characteristics of the sampling site; S3. Calculate the relative content of each mineral based on the chemical formula and XRF data of the mineral types determined in step S2; When selecting the minerals that match the elements in the XRF one by one, substitute them into formula (1) to calculate the relative content of the mineral; the formula (1) is: In formula (1), B1O v represents the oxide corresponding to a certain element B; B1O v % represents the percentage content of this oxide in the XRF result; M B1Ov represents the molar mass of the oxide corresponding to a certain element B in mineral A; M A represents the molar mass of mineral A; A% represents the percentage content of the mineral containing a certain element B; When a certain same element is contained in two or more minerals, substitute them into formula (2) to solve the relative content of each mineral respectively, and the formula (2) is In formula (2): A1, A2, A3... A n represent different minerals; A1%, A2%, A3%... A n % represent the percentage content of different minerals containing an element B; M B1Ov (A1), M B1Ov (A2), M B1Ov (A3),... M B1Ov (A n ) represents the molar mass of the oxide corresponding to element B in different minerals A1 - A n ; represents the molar mass of different minerals; B% represents the percentage content of the oxide of element B in the XRF test; S4. Normalize the relative content of each mineral calculated in step S3, and finally obtain the relative proportion of each mineral.

2. The semi - quantitative analysis method for the mineral content in debris flow samples according to claim 1, characterized in that, The drying condition in step S1 is drying at 105°C for 2 h, and the ablation condition is ablation at 900 - 950°C for 2 h.

3. The semi - quantitative analysis method for the mineral content in debris flow samples according to claim 1, characterized in that, When selecting the minerals corresponding to the XRF elements in step S2, set the threshold of the element content to 0.1%, and ignore the element when the element content is lower than this value.

4. The semi - quantitative analysis method for the mineral content in debris flow samples according to claim 1, characterized in that, When matching the diffraction peaks obtained from the XRD test according to the X-ray diffraction standard cards in step S2, discard the diffraction peaks with intensity < 300.

5. The semi - quantitative analysis method for the mineral content in debris flow samples according to claim 1, characterized in that, When there is isomorphism in the mineral in step S3, first set the substitution ratio of isomorphism, and then calculate the relative content of each mineral; among them, the range of the isomorphism substitution ratio is: Mg / Fe in chlorite is 1 / 5 - 7 / 3; Al / Si in feldspar is 0 - 1.

6. The semi - quantitative analysis method for the mineral content in debris flow samples according to claim 1, characterized in that, The normalization in step S4 is carried out using formula (3), and the formula (3) is: N i = A i / N, i = 1, 2, 3, 4……m (3) Where A i represents the calculated percentage content of the corresponding mineral, and N1, N2, …, N m represent the relative content of the corresponding mineral after normalization, and N is the total element content, which is equal to 1 - loss on ignition.

7. The semi - quantitative analysis method for the mineral content in debris flow samples according to claim 1, characterized in that, The debris flow sample is a debris flow sample from the Jinsha River Basin.

Images