Method for measuring gold in gold mine through field X fluorescence

Abstract

The invention belongs to the technical field of rock ore testing, and particularly relates to a method for measuring gold in gold ore by field X fluorescence, which comprises the following steps: wetting a gold-containing sample with water, sequentially adding nitric acid and hypochlorous acid, heating, and oxidizing carbonaceous substances and sulfides in the gold-containing sample by a hypochlorous acid wet process to obtain the gold-containing sample without the carbonaceous substances and the sulfides; redissolving with an aqua regia solution, heating for dissolving, cooling, adding water and foamed plastic, oscillating, taking out the foamed plastic, and absorbing water to obtain foamed plastic adsorbed with gold; putting the foamed plastic adsorbed with gold into a colorimetric tube containing a thiourea solution, and performing thiourea gold removal in a boiling water bath; the invention discloses a method for rapidly and greenly measuring gold in a gold mine through field X fluorescence, which comprises the following steps of: drawing a standard curve by using a gold standard solution, measuring a fluorescence value of a to-be-measured solution by using X fluorescence under a prepared working condition, and comparing the standard curve to obtain the corresponding gold content, and is suitable for implementation of field on-site analysis of gold.

Description

Technical Field

[0001] The invention belongs to the technical field of rock and mineral testing, and in particular relates to a method for field X-ray fluorescence determination of gold in a gold mine. Background Art

[0002] Gold mines are mineral resources with financial value. They are related to the overall and strategic issues of national economic security and are vital to national prosperity and development, improvement of people's lives, and long-term social stability. Rapid field analysis of gold is of great significance to improving the efficiency of gold mine exploration and development, especially in remote areas such as the west. It can greatly shorten the sample transportation and detection cycle and help the high-quality development of geological surveys. Therefore, its detection method is a hot spot and difficulty in current research, and is highly valued by researchers.

[0003] The gold grade in gold mines is low and unevenly distributed. They often contain sulfides and organic matter that affect the leaching of gold. The characteristics of gold make it difficult to analyze it in the field. The existing supporting methods for field analysis are single. Conventional methods require a large amount of sampling and determination after roasting-digestion-pre-enrichment. There are many problems. First, the large amount of waste gas generated by roasting sulfides and carbonaceous materials in field samples is difficult to handle; second, the analysis environment conditions such as field pressure and temperature are difficult to control, which directly affects the accuracy and stability of gold analysis; third, it is difficult to purchase and store hazardous chemicals such as acetylene in the field when determining by flame atomic absorption method. The existing solutions are mainly concentrated in the field of back-end detection of gold. The predecessors have developed "field gold rapid analysis box" and "gold, silver and other multi-element rapid analyzer". The sample pretreatment method still uses high-temperature roasting-aqua regia digestion-foam plastic pre-enrichment of gold, which is difficult to apply in the field, and the gold detection results are low in high-altitude areas. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a method for determining gold in a gold mine by field X-ray fluorescence. The present invention establishes a method for rapid and green determination of gold in a gold mine by field X-ray fluorescence, which is suitable for the implementation of field on-site analysis of gold.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A method for determining gold in a gold mine by field X-ray fluorescence comprises the following steps:

[0007] After wetting the gold-containing sample with water, nitric acid and hypochlorous acid are added in sequence, and the sample is heated. The carbonaceous matter and sulfide in the gold-containing sample are oxidized by hypochlorous acid wet method to obtain the gold-containing sample with the carbonaceous matter and sulfide removed.

[0008] The gold-containing sample from which carbonaceous matter and sulfide have been removed is redissolved in aqua regia solution, heated to dissolve, then cooled, water and foam plastics are added, shaken, the foam plastics are taken out, rinsed with water to remove acid and residue, and then the water is absorbed to obtain foam plastics adsorbed with gold.

[0009] The foam plastic adsorbed with gold is placed in a colorimetric tube containing thiourea solution, and the gold is desorbed by thiourea in a temperature-controlled device. The foam plastic is taken out and cooled to room temperature to obtain a test solution.

[0010] A standard curve was drawn using the gold standard solution.

[0011] Under the proposed working conditions, the fluorescence value of the test liquid is measured by X-ray fluorescence, and the corresponding gold content is obtained by comparing with the standard curve.

[0012] The invention firstly adds nitric acid and hypochlorous acid to a gold-containing sample, adopts hypochlorous acid to oxidize carbonaceous matter and sulfide in the gold ore to eliminate the influence on gold determination, and replaces high-temperature roasting of the sample by adding hypochlorous acid wet oxidation. The new ecological oxygen generated by the decomposition of hypochlorous acid has extremely strong oxidizing property, and the carbonaceous matter and sulfide in the sample are quickly oxidized in a nitric acid medium, thereby eliminating the sample pre-roasting step and solving the problem of large amount of waste polluting the environment generated by roasting. In view of the fact that the analysis environment conditions such as the temperature and the atmospheric pressure in the field are difficult to control, the temperature control equipment is adopted to accurately control the temperature for thiourea release, so as to improve the gold elution efficiency and the accuracy and stability of the gold monitoring result. The portable energy dispersive X-ray fluorescence instrument is adopted to accurately monitor the gold in the sample solution, so as to replace the traditional flame atomic absorption instrument to detect the gold, thereby avoiding the use of acetylene and other fuel gases in the field, and being more green and safe.

[0013] In a preferred embodiment of the present invention, the usage ratio of the gold-containing sample to hypochlorous acid is 1.0000 g: 0.4 mL to 0.6 mL, and the usage ratio of the gold-containing sample to nitric acid is 1.0000 g: 1.8 mL to 2.2 mL.

[0014] In a preferred embodiment of the present invention, the hypochlorous acid wet oxidation time is 8 min to 12 min.

[0015] In a preferred embodiment of the present invention, the concentration of nitric acid is 0.90 g / mL to 0.96 g / mL, and the concentration of hypochlorous acid is 0.9 mg / mL to 1.1 mg / mL.

[0016] In a preferred embodiment of the present invention, when the carbonaceous matter and sulfide in the gold-containing sample are wet oxidized by hypochlorous acid, it is observed whether there is a black carbon film floating on the surface of the solution. If there is no black carbon film, hypochlorous acid is added and heated to a water-free state. If there is a black carbon film, hypochlorous acid is added and heated until the black carbon film disappears, and then hypochlorous acid is added and heated to a water-free state to obtain a gold-containing sample with carbonaceous matter and sulfide removed.

[0017] In a preferred embodiment of the present invention, the volume concentration of aqua regia solution is 45% to 55%.

[0018] In a preferred embodiment of the present invention, the temperature control device sets the thiourea gold removal temperature to 99°C to 101°C, and the thiourea gold removal time to 28min to 32min.

[0019] In a preferred embodiment of the present invention, the mass concentration of the thiourea solution is 0.95% to 1.05%.

[0020] In a preferred embodiment of the present invention, the proposed working conditions are:

[0021] The Au-Lα line of gold is selected as the analysis spectrum line, the maximum peak is the actual detection peak, the spectroscopic crystal is LiF1, the detector is a PC detector, the measurement time is 50s, the tube voltage of the X-ray fluorescence spectrometer is 40kV~50kV, and the tube current is 60mA~80mA.

[0022] In a preferred embodiment of the present invention, the foam plastic is a polyether foam plastic.

[0023] In a preferred embodiment of the present invention, a gold standard solution with a gold ion concentration of 10 mg / L is prepared, and 0 mL, 0.1 mL, 0.5 mL, 1.0 mL, 2.0 mL, 5.0 mL, 10 mL, 15 mL, and 20 mL of the gold standard solution are taken respectively, 20 mL of aqua regia and 80 mL of water are added, and a polyether foam plastic is put into the same sample, and adsorption and release are carried out together with the sample, and a standard curve is drawn with the mass concentration of gold as the abscissa and the corresponding fluorescence intensity as the ordinate, wherein the mass concentration of gold is 0 mg / L, 0.1 mg / L, 0.5 mg / L, 1.0 mg / L, 2.0 mg / L, 5.0 mg / L, 10 mg / L, 15 mg / L, and 20 mg / L, respectively.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The present invention first adds nitric acid and hypochlorous acid to a gold-containing sample, uses hypochlorous acid to oxidize carbonaceous matter and sulfide in the gold ore to eliminate the influence on gold determination, and replaces high-temperature roasting of the sample by adding hypochlorous acid wet oxidation. The new ecological oxygen generated by the decomposition of hypochlorous acid has extremely strong oxidizing property, and quickly oxidizes carbonaceous matter and sulfide in the sample in a nitric acid medium, thereby eliminating the sample pre-roasting step and solving the problem of a large amount of waste generated by roasting and polluting the environment; in view of the fact that the analysis environment conditions such as field temperature and atmospheric pressure are difficult to control, a temperature control device is used to accurately control the temperature for thiourea release, so as to improve the gold elution efficiency and improve the accuracy and stability of the gold monitoring result; a portable energy dispersive X-ray fluorescence instrument is used to accurately monitor the gold in the sample solution, replacing the traditional flame atomic absorption instrument to detect gold, avoiding the use of acetylene and other fuel gases in the field, and being more green and safe.

[0026] 2. The present invention establishes a method for rapid green determination of gold in gold mines by field X-ray fluorescence, which is suitable for the implementation of field on-site analysis of gold. DETAILED DESCRIPTION

[0027] The following is a detailed description of the technical solutions in the embodiments of the present invention in combination with preferred embodiments and data. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] It should be noted that all professional terms used in the present invention are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention. Unless otherwise specifically stated, various raw materials, reagents, instruments and equipment used in the following embodiments of the present invention can be purchased from the market or prepared by existing methods.

[0029] In view of the problem that sulfides and organic matter contained in gold mines affect the leaching of gold, samples need to be roasted at high temperature, which consumes a lot of energy and pollutes the environment in the field, the present invention replaces the high-temperature roasting of samples by quantitatively adding hypochlorous acid for wet oxidation. The new ecological oxygen generated by the decomposition of hypochlorous acid has extremely strong oxidizing property, and quickly oxidizes the carbonaceous matter and sulfide in the sample in a nitric acid medium to eliminate their adverse effects on gold determination.

[0030] Aiming at the problem that the temperature of boiling water bath does not meet the standard (100°C) in the field, especially in high-altitude areas, the gold is not completely released by thiourea boiling water bath after gold is enriched by foam plastic, and the test result is seriously low, the present invention uses thiourea to release gold by precise temperature control (100°C) of an oven to improve the gold elution efficiency, effectively avoid the adverse effect of the field environment on the gold detection result, and obtain the optimal gold release time through experiments.

[0031] In view of the problem that the existing flame atomic absorption spectrometer uses acetylene and other fuel gases when detecting gold, which poses a great safety risk, the present invention adopts a portable energy dispersive X-ray fluorescence spectrometer to establish a gold standard curve. The device does not need to use gas, and the determination results of heavy elements such as gold are accurate and reliable, replacing the traditional flame atomic absorption spectrometer for determining gold.

[0032] Drawing of standard curve

[0033] 0, 0.1, 0.5, 1.0, 2.0, 5.0, 10, 15, 20 mL of gold standard solution (10 mg / L) were respectively transferred into a group of 300 mL conical flasks, 20 mL of aqua regia (1+1) and 80 mL of water were added, a piece of 3×1.5×1.5 cm small-pore polyether foam was placed in it, and adsorption and release were performed together with the sample (see steps (4) to (6) in the embodiment for the steps). The working curve was drawn with the mass concentration of gold as the horizontal axis and the corresponding fluorescence intensity as the vertical axis. The mass concentration of gold in this standard curve was 0, 0.1, 0.5, 1.0, 2.0, 5.0, 10, 15, 20 mg / L, respectively.

[0034] Example 1

[0035] A method for determining gold in a gold mine by field X-ray fluorescence comprises the following steps:

[0036] (1) Accurately weigh 10.0000 g of sample into a 300 mL conical flask, moisten it with water, add 20 mL of nitric acid and 5 mL of hypochlorous acid in sequence, cover it with a watch glass, place it on a hot plate and heat it, keeping it at a slight boiling state for 10 min.

[0037] (2) Observe whether there is a thin layer of black carbon film floating on the surface of the solution. If not, add 1.00 mL of hypochlorous acid and heat until it is nearly dry. If so, add 1.00 mL of hypochlorous acid and heat for 5 min until the black carbon film disappears. Then add 1.00 mL of hypochlorous acid and heat until it is nearly dry to obtain a gold-containing sample with carbonaceous matter and sulfide removed.

[0038] (3) The gold-containing sample from which the carbonaceous matter and sulfide have been removed is re-dissolved in 80 mL of 50% aqua regia solution and dissolved at a slight boiling temperature for more than 50 min until the volume of the test solution is about 15 mL, and then removed and cooled.

[0039] (4) Add 80 mL of water and a 3 cm × 1.5 cm × 1.5 cm small-pore polyether foam plastic, cover with a rubber stopper, and oscillate on an oscillator for 30 min. Take out the foam plastic, wash off the acid and residue with tap water, and then rinse with water three times. Use filter paper to absorb the water to obtain the foam plastic adsorbed with gold.

[0040] (5) Place the foam plastic adsorbed with gold into a colorimetric tube containing 10 mL of 1% thiourea solution, and place it in an oven at 100°C for 30 min to de-gold it with thiourea. Remove the foam plastic and squeeze it with a glass rod several times to make the de-gold solution uniform.

[0041] (6) Take out the foam plastic, cool it to room temperature, and obtain the test liquid. Select the Au-Lα line of gold as the analysis spectrum line, the maximum peak position is the actual detection peak position, the spectroscopic crystal is LiF1, the detector is a PC detector, the measurement time is 50 s, and the fluorescence value of the test liquid is measured by an X-ray fluorescence spectrometer. The tube voltage of the X-ray fluorescence spectrometer is 45 kV, and the tube current is 70 mA. By comparing with the standard curve, the corresponding gold content is obtained.

[0042] Example 2

[0043] A method for determining gold in a gold mine by field X-ray fluorescence comprises the following steps:

[0044] (1) Accurately weigh 10.0000 g of sample into a 300 mL conical flask, moisten it with water, add 18 mL of nitric acid and 4 mL of hypochlorous acid in sequence, cover it with a watch glass, place it on a hot plate and heat it, keeping it at a slight boiling state for 8 min.

[0045] (2) Observe whether there is a thin layer of black carbon film floating on the surface of the solution. If not, add 1.00 mL of hypochlorous acid and heat until it is nearly dry. If so, add 1.00 mL of hypochlorous acid and heat for 5 min until the black carbon film disappears. Then add 1.00 mL of hypochlorous acid and heat until it is nearly dry to obtain a gold-containing sample with carbonaceous matter and sulfide removed.

[0046] (3) The gold-containing sample from which the carbonaceous matter and sulfide have been removed is re-dissolved in 80 mL of 45% aqua regia solution and dissolved at a slight boiling temperature for more than 50 min until the volume of the test solution is about 15 mL, and then removed and cooled.

[0047] (4) Add 80 mL of water and a 3 cm × 1.5 cm × 1.5 cm small-pore polyether foam plastic, cover with a rubber stopper, and oscillate on an oscillator for 30 min. Take out the foam plastic, wash off the acid and residue with tap water, and then rinse with water three times. Use filter paper to absorb the water to obtain the foam plastic adsorbed with gold.

[0048] (5) Place the foam plastic adsorbed with gold into a colorimetric tube containing 10 mL of 0.95% thiourea solution, and place it in an oven at 99°C for 28 min to de-gold it with thiourea. Remove the foam plastic and squeeze it with a glass rod several times to make the de-gold solution uniform.

[0049] (6) Take out the foam plastic, cool it to room temperature, and obtain the test liquid. Select the Au-Lα line of gold as the analysis spectrum line, the maximum peak position is the actual detection peak position, the spectroscopic crystal is LiF1, the detector is a PC detector, the measurement time is 50 s, and the fluorescence value of the test liquid is measured by an X-ray fluorescence spectrometer. The tube voltage of the X-ray fluorescence spectrometer is 40 kV, and the tube current is 60 mA. By comparing with the standard curve, the corresponding gold content is obtained.

[0050] Example 3

[0051] A method for determining gold in a gold mine by field X-ray fluorescence comprises the following steps:

[0052] (1) Accurately weigh 10.0000 g of sample into a 300 mL conical flask, moisten it with water, add 22 mL of nitric acid and 6 mL of hypochlorous acid in sequence, cover it with a watch glass, place it on a hot plate and heat it, keeping it at a slight boiling state for 12 min.

[0053] (2) Observe whether there is a thin layer of black carbon film floating on the surface of the solution. If not, add 1.00 mL of hypochlorous acid and heat until it is nearly dry. If so, add 1.00 mL of hypochlorous acid and heat for 5 min until the black carbon film disappears. Then add 1.00 mL of hypochlorous acid and heat until it is nearly dry to obtain a gold-containing sample with carbonaceous matter and sulfide removed.

[0054] (3) The gold-containing sample from which the carbonaceous matter and sulfide have been removed is re-dissolved in 80 mL of 55% aqua regia solution and dissolved at a slight boiling temperature for more than 50 min until the volume of the test solution is about 15 mL, and then removed and cooled.

[0055] (4) Add 80 mL of water and a 3 cm × 1.5 cm × 1.5 cm small-pore polyether foam plastic, cover with a rubber stopper, and oscillate on an oscillator for 30 min. Take out the foam plastic, wash off the acid and residue with tap water, and then rinse with water three times. Use filter paper to absorb the water to obtain the foam plastic adsorbed with gold.

[0056] (5) Place the foam plastic adsorbed with gold into a colorimetric tube containing 10 mL of 1.05% thiourea solution, and place it in an oven at 101°C for 32 minutes to de-gold it with thiourea. Remove the foam plastic and squeeze it several times with a glass rod to make the de-gold solution uniform.

[0057] (6) Take out the foam plastic, cool it to room temperature, and obtain the test liquid. Select the Au-Lα line of gold as the analysis spectrum line, the maximum peak position is the actual detection peak position, the spectroscopic crystal is LiF1, the detector is a PC detector, the measurement time is 50 s, and the fluorescence value of the test liquid is measured by an X-ray fluorescence spectrometer. The tube voltage of the X-ray fluorescence spectrometer is 50 kV, and the tube current is 80 mA. By comparing with the standard curve, the corresponding gold content is obtained.

[0058] Results Analysis

[0059] Determination of gold content of gold ore standard substance in Example 1

[0060] 0, 0.1, 0.5, 1.0, 2.0, 5.0, 10, 15, 20 mL of gold standard solution (10 mg / L) were respectively transferred into a group of 300 mL conical flasks, 20 mL of aqua regia (1+1) and 80 mL of water were added, and a piece of 3 cm × 1.5 cm × 1.5 cm small-pore polyether foam plastic was placed in it, and adsorption and release were performed together with the sample. X-ray fluorescence measurement was performed on 9 groups of working curve points, and the measurement results of each curve point are shown in Table 1. The deviation between the test value and the standard value is small.

[0061] Table 1 Gold working curve point X-ray fluorescence measurement results

[0062]

[0063]

[0064] The present invention takes 6 national standard materials of gold ores as examples, namely national standard materials GBW(E)070012, GBW(E)070013, GBW(E)070014a, GBW07300, GBW(E)070015a and GBW07297a. According to the determination method of the present invention, by comparing the standard working curve, the gold contents in the 6 national standard materials of gold ores are respectively determined and recorded as shown in Table 2. The determination results are consistent with the standard values.

[0065] Table 2 Determination results of national standard materials for gold ore

[0066]

[0067] Determination of gold content in actual gold ore samples

[0068] The present invention takes 6 actual samples of gold ore as examples, the actual samples are numbered S1-S6, and according to the determination method of the present invention, the gold content in the 6 actual samples of gold ore is respectively determined by comparing with the standard working curve, and the method control experiment is carried out using "Chemical Analysis Method of Gold Ore Part 1 Determination of Gold Content Flame Atomic Absorption Method" (GB / T 20899.1-2019), and the results are recorded as shown in Table 3. The determination results of X-ray fluorescence method and flame atomic absorption method are consistent.

[0069] Table 3 Gold ore actual sample determination results

[0070]

[0071] In summary, the present invention first adds nitric acid and hypochlorous acid to the gold-containing sample, uses hypochlorous acid to oxidize carbonaceous materials and sulfides in the gold ore to eliminate the influence on gold determination, and replaces the high-temperature roasting sample by adding hypochlorous acid wet oxidation. The new ecological oxygen generated by the decomposition of hypochlorous acid has extremely strong oxidizing properties, and the carbonaceous materials and sulfides in the sample are quickly oxidized in the nitric acid medium, eliminating the sample pre-roasting step, and solving the problem of a large amount of waste pollution caused by roasting; in view of the fact that the analysis environment conditions such as field temperature and atmospheric pressure are not easy to control, the temperature control equipment is used to accurately control the temperature for thiourea release, so as to improve the elution efficiency of gold and improve the accuracy and stability of the gold monitoring results; a portable energy dispersive X-ray fluorescence instrument is used to accurately monitor the gold in the sample solution, replacing the traditional flame atomic absorption instrument to detect gold, avoiding the use of acetylene and other fuel gases in the field, and being more green and safe. The present invention establishes a method for rapid green determination of gold in gold mines by field X-ray fluorescence, which is suitable for the implementation of field analysis of gold.

[0072] It should be noted that when the present invention involves a numerical range, it should be understood that the two endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as those in the embodiments, in order to avoid redundancy, the present invention describes a preferred embodiment. Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the attached claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0073] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for determining gold in a gold mine by X-ray fluorescence in the field, characterized in that: The following steps are involved: After wetting the gold-containing sample with water, nitric acid and hypochlorous acid are added in sequence, and carbonaceous matter and sulfide in the gold-containing sample are oxidized by hypochlorous acid wet method to obtain the gold-containing sample with carbonaceous matter and sulfide removed; The gold-containing sample from which the carbonaceous matter and the sulfide have been removed is redissolved in aqua regia solution, and foam plastic is added to adsorb the gold, thereby obtaining foam plastic adsorbed with gold; The foam plastic adsorbed with gold is placed in a thiourea solution, the thiourea is used to de-gold the foam plastic in a temperature control device, the foam plastic is taken out, and the foam plastic is cooled to room temperature to obtain a test solution; Under the proposed working conditions, the fluorescence value of the test liquid is measured by X-ray fluorescence, and the corresponding gold content is obtained by comparing with the standard curve.

2. The method for determining gold in a gold mine by field X-ray fluorescence according to claim 1, characterized in that: The usage ratio of gold-containing sample to hypochlorous acid is 1g:0.4mL~0.6mL, the usage ratio of gold-containing sample to nitric acid is 1g:1.8mL~22mL, the mass concentration of nitric acid is 0.90g / mL~0.96g / mL, and the mass concentration of hypochlorous acid is 0.9mg / mL~1.1mg / mL.

3. The method for determining gold in a gold mine by field X-ray fluorescence according to claim 1, characterized in that: The hypochlorous acid wet oxidation time is 8 minutes to 12 minutes.

4. The method for determining gold in a gold mine by field X-ray fluorescence according to claim 1, characterized in that: When the carbonaceous matter and sulfide in the gold-containing sample are oxidized by the hypochlorous acid wet method, observe whether there is a black carbon film floating on the surface of the solution. If there is no black carbon film, add hypochlorous acid and continue to heat it to a water-free state. If there is a black carbon film, add hypochlorous acid and heat it until the black carbon film disappears, and then add hypochlorous acid and heat it to a water-free state to obtain a gold-containing sample with carbonaceous matter and sulfide removed.

5. The method for determining gold in a gold mine by field X-ray fluorescence according to claim 1, characterized in that: The temperature control device sets the thiourea gold removal temperature to 99° C. to 101° C., and the thiourea gold removal time to 28 min to 32 min.

6. The method for determining gold in a gold mine by field X-ray fluorescence according to claim 1, characterized in that: The mass concentration of the thiourea solution is 0.95% to 1.05%.

7. The method for determining gold in a gold mine by field X-ray fluorescence according to claim 1, characterized in that: The volume concentration of aqua regia solution is 45% to 55%.

8. The method for determining gold in a gold mine by field X-ray fluorescence according to claim 1, characterized in that: The proposed working conditions are: The Au-Lα line of gold is selected as the analysis spectrum line, the maximum peak position is the actual detection peak position, the spectroscopic crystal is LiF1, the detector is a PC detector, the tube voltage of the X-ray fluorescence spectrometer is 40kV~50kV, and the tube current is 60mA~80mA.

9. The method for determining gold in a gold mine by field X-ray fluorescence according to claim 1, characterized in that: The foam plastic is a polyether foam plastic.

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