Field rapid analysis method for trace gold

Abstract

The invention discloses a field rapid analysis method for trace gold, which comprises the following steps: S1, ore dissolution: taking a rock mineral sample in a container, adding a dissolving agent, and heating until the sample is slightly boiled for high-temperature ore dissolution; the dissolving agent is hydrochloric acid, potassium nitrate and nitric acid; s2, enrichment: adding polypropyleneimine into the mineral solution, standing, taking clear liquid, diluting with hydrochloric acid, slowly dropwise adding to pass through an adsorption column filled with sulfydryl cotton, taking out the sulfydryl cotton, and washing with a solvent; s3, secondary ore dissolving after ashing: squeezing the washed sulfydryl cotton to be dry, heating until the sulfydryl cotton is ashed, then adding hydrochloric acid, and drying by distillation in a water bath; s4, determination: adding a masking agent and hydrochloric acid after drying by distillation, transferring to a colorimetric tube, dropwise adding urea and a TMK color developing agent, uniformly mixing, standing, and carrying out visual colorimetry with a standard series; the masking agent is a mixture of malic acid, glutaric acid and ethylenediaminetetraacetic acid. According to the method, trace gold can be effectively enriched, and the method is safer and more convenient while the analysis sensitivity and accuracy are guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of field gold analysis, and in particular to a field rapid analysis method for trace gold. Background Art

[0002] An important problem that often needs to be solved in the field geological exploration and development and utilization of gold mines is the accurate and rapid analysis of gold samples. There are many types of geological ore samples with complex compositions. Even experienced prospectors cannot distinguish the mineralization of gold ore with the naked eye, and must rely heavily on test data to distinguish ore rocks. However, with the increase in sampling, the workload of testing also increases, and the test results lag behind. In the long run, it is not conducive to the timely adjustment of prospecting, the submission of information, the control of dilution losses, and the adjustment of the ore grade. It is urgent to introduce a detection and analysis method that can quickly issue the test results of gold in ore.

[0003] There are few reports on scientific research results on rapid gold detection in China, but there are fruitful results in the detection of trace gold in the laboratory, which shows that there are certain difficulties and obstacles in the rapid detection of gold in the field. Patent 95104893.7 provides a method for rapid determination of gold grade, which adopts the foam plastic adsorption visual colorimetry method. After the ore sample is dissolved with dilute hydrochloric acid and hydrogen peroxide, a mixed masking agent composed of sodium fluoride solution, ammonium chloride solution, EDTA solution, urea solution and sodium acetate solution in a certain volume ratio is added. After color development, the gold grade can be measured. However, there is a risk of overflow of strong acidic solution and injury during the foam plastic vibration adsorption process and toxic gas leakage and injury during the foam plastic ashing process, which brings inconvenience to the determination and makes it difficult to promote the use of the method. Therefore, it is urgent to develop a safe and efficient field rapid analysis method for trace gold. Summary of the invention

[0004] In view of this, the present invention proposes a field rapid analysis method for trace gold to solve the above problems.

[0005] The technical solution of the present invention is achieved in this way:

[0006] A field rapid analysis method for trace gold comprises the following steps:

[0007] S1. Dissolving ore: taking a rock mineral sample into a container, adding a dissolving agent, heating to a slight boiling point to dissolve the ore at high temperature, and obtaining a mineral solution; the dissolving agent is a hydrochloric acid solution, potassium nitrate powder and a nitric acid solution;

[0008] S2, enrichment: add polypropylene imine to the mineral solution, let it stand, take the clear solution and dilute it with hydrochloric acid, slowly drip it through the adsorption column equipped with thiol cotton, take out the thiol cotton and wash it with solvent;

[0009] S3, secondary ore dissolution after ashing: squeeze the washed mercapto cotton dry, heat it until ashing, add hydrochloric acid, and evaporate it in a water bath;

[0010] S4. Determination: After evaporation, add masking agent and hydrochloric acid, transfer to a colorimetric tube, add urea and TMK color developer, mix well, let stand, and compare color with the standard series visually.

[0011] Preferably, the S1 ore dissolving is specifically as follows: taking a rock mineral sample in a conical beaker, adding potassium nitrate powder and then adding hydrochloric acid solution and stirring evenly, heating to a slight boil for 15 to 20 minutes after the reaction stops, cooling, then adding nitric acid solution and continuing to heat to a slight boil for about 15 to 20 minutes, cooling to room temperature, and diluting with purified water.

[0012] Preferably, the mass ratio of the potassium nitrate powder to the mineral sample is 1:10; the mass volume ratio of the mineral sample to the hydrochloric acid solution is 1g:2-3mL; the mass volume ratio of the mineral sample to the nitric acid solution is 1g:1-2mL.

[0013] Preferably, the mass volume ratio of the mineral sample to the solution diluted with pure water is 1 g: 10-15 mL.

[0014] Preferably, the flow rate of slowly dripping through the adsorption column equipped with mercapto cotton is 15 to 20 d / min.

[0015] Preferably, the taking out the mercapto cotton and washing it with a solvent specifically comprises taking out the mercapto cotton and washing it once with hydrochloric acid and then washing it three times with pure water.

[0016] Preferably, the masking agent is a mixture of malic acid, glutaric acid and ethylenediaminetetraacetic acid.

[0017] Preferably, the mass ratio of malic acid, glutaric acid and ethylenediaminetetraacetic acid is 1-3:1:1.

[0018] Preferably, the masking agent is prepared by weighing glutaric acid, malic acid, and ethylenediaminetetraacetic acid (EDTA) in a container, adding ammonia water and distilled water, stirring and dissolving, transferring into a clean container and adjusting the pH to 3.5-4 with acetic acid-sodium acetate buffer; the masking agent is prepared in advance in the laboratory for use.

[0019] These three chemical substances have different complexing properties and metal ion selectivity. Using their respective properties to shield different metal ions can complement each other's masking properties, which can more comprehensively reduce the interference of other metal ions on gold analysis results and improve the accuracy and reliability of the analysis.

[0020] Preferably, the color developer is prepared by dissolving thiomikler's ketone (TMK) in anhydrous ethanol until saturated, and taking the supernatant for use.

[0021] Preferably, the technical principle of the present invention is: using a solvent to dissolve the ore, adding polypropylene imine and then enriching it with mercapto cotton, removing mercury by ashing, adding a masking agent to remove interfering elements such as lead, arsenic, antimony, and thallium, and dripping thiomikler's ketone (TMK) for color development. According to the yellow-green, light pink, pink, purple-red, dark purple, etc., the approximate content of gold in the rock sample can be determined. Generally speaking, the higher the gold grade in the ore, the darker the red and purple-red color will be. If it is yellow-green, it is consistent with the color of the blank test, indicating that the rock does not contain gold.

[0022] The mineral solution contains a certain amount of soluble silicate. When the mercapto cotton absorbs gold, the test result will be low. Polypropylene imine has multiple amino (-NH2) functional groups, which can react with the silicate ion (SiO3 2 -) interaction, effectively fixing the silicate in the structure of polypropyleneimine to form a stable complex or colloidal structure. Therefore, polypropyleneimine is added before adsorption to condense the silicate and remove it by filtration. Polypropyleneimine does not affect the adsorption of gold.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention provides a field rapid analysis method for trace gold. Through the steps of ore dissolution and enrichment, trace gold can be effectively enriched, the sensitivity and accuracy of analysis can be improved, and reliable detection can be performed even if the metal content in the sample is low. In addition, the operation steps of the method are relatively simple, and no complicated instruments and equipment are required. It mainly relies on simple chemical reagents and basic laboratory equipment, which is convenient to carry out under field conditions. The overall operation of the method is relatively fast, and the process from sample preparation to analysis result acquisition can be completed in a relatively short time, which is suitable for on-site real-time analysis requirements. The reagents used in the field rapid analysis method for trace gold provided by the present invention are all selected from reagents with low toxicity. When gold mines are explored under field conditions, the harm to the environment and human body is small. The method is safe and simple to operate, and is more practical in field exploration. DETAILED DESCRIPTION

[0025] In order to better understand the technical content of the present invention, specific embodiments are provided below to further illustrate the present invention.

[0026] Unless otherwise specified, the experimental methods used in the embodiments of the present invention are all conventional methods.

[0027] Unless otherwise specified, the materials, reagents, etc. used in the embodiments of the present invention can be obtained from commercial sources.

[0028] Preparation of color developer: Dissolve thiomikler's ketone (TMK) in anhydrous ethanol until saturated, and use the supernatant.

[0029] Example 1

[0030] A field rapid analysis method for trace gold comprises the following steps:

[0031] S1. Ore dissolution: weigh 10g of rock mineral sample into a 125mL conical beaker, add 1g of potassium nitrate powder and slowly add 20mL of 12M hydrochloric acid solution. After the reaction stops, heat to a slight boil for 20min, remove and cool slightly, add 15mL of 8M nitric acid solution and continue to heat to a slight boil for about 20min, cool to room temperature, and dilute to 100mL with purified water.

[0032] S2, enrichment: add 5 drops of polypropylene imine, let stand for 20 minutes, separate 5 ml of the liquid into a beaker, dilute to 100 mL with 10 vol% hydrochloric acid, slowly drip through the adsorption column equipped with thiol cotton at a speed of 20 d / min, take out the thiol cotton, wash it once with hydrochloric acid and then wash it three times with pure water;

[0033] S3. Secondary ore dissolution after ashing: squeeze the washed mercapto cotton dry and put it into a porcelain crucible, heat it to 800℃ for ashing, take it out and add 1mL 15% hydrochloric acid, evaporate it in a water bath.

[0034] S4. After evaporation, add 2 mL of masking agent and 5 mL of 5 vol% hydrochloric acid, transfer to a colorimetric tube, then add 5 drops of 10% urea and 5 drops of color developer, shake vigorously to mix evenly, let stand to separate layers, and then compare the color with the standard series visually.

[0035] The masking agent is prepared in the laboratory in advance and can be stored for a certain period of time in the field. The preparation method is as follows: weigh 15g malic acid, 10g glutaric acid, and 10g ethylenediaminetetraacetic acid (EDTA) in a 500mL beaker, add 10mL ammonia water, add 200mL distilled water, stir well to dissolve, transfer to a clean container, and adjust the pH to 3.5-4 with acetic acid-sodium acetate buffer.

[0036] How to make standard color scale:

[0037] Pipette Au standard solutions containing 0, 0.1, 0.25, 0.5, 0.75, 1, 1.5, 2, 5, 7, and 10 mg / L into 10 mL porcelain crucibles respectively, add 50 μg FeCl3 solution, and the following operations are the same as the rock sample analysis steps.

[0038] Example 2

[0039] A field rapid analysis method for trace gold comprises the following steps:

[0040] S1. Dissolving ore: weigh 10g sample into a 125mL conical beaker, add 1g potassium nitrate powder and slowly add 30mL 12M hydrochloric acid solution. After the reaction stops, heat to a slight boil for 20min, remove and cool slightly, add 10mL 8M nitric acid solution and continue to heat to a slight boil for about 15min, cool to room temperature, and dilute to 150mL with purified water.

[0041] S2, enrichment: add 5 drops of polypropylene imine, let stand for 20 minutes, separate 5 ml of the liquid into a beaker, dilute to 100 mL with 10 vol% hydrochloric acid, slowly drip through the adsorption column equipped with thiol cotton at a speed of 20 d / min, take out the thiol cotton, wash it once with hydrochloric acid and then wash it three times with pure water;

[0042] S3. Secondary ore dissolution after ashing: squeeze the washed mercapto cotton dry and put it into a porcelain crucible, heat it to 800℃ for ashing, take it out and add 1mL 15% hydrochloric acid, evaporate it in a water bath.

[0043] S4. After evaporation, add 2 mL of masking agent and 5 mL of 5 vol% hydrochloric acid, transfer to a colorimetric tube, then add 5 drops of 10% urea and 5 drops of color developer, shake vigorously to mix evenly, let stand to separate layers, and then compare the color with the standard series visually.

[0044] The masking agent is prepared in advance in the laboratory and can be stored for a certain period of time in the field. The preparation method is as follows: weigh 11.67g malic acid, 11.67g glutaric acid, and 11.67g ethylenediaminetetraacetic acid (EDTA) in a 500mL beaker, add 10mL ammonia water, add 200mL distilled water, stir well to dissolve, transfer to a clean container, and adjust the pH to 3.5-4 with acetic acid-sodium acetate buffer.

[0045] How to make standard color scale:

[0046] Pipette Au standard solutions containing 0, 0.1, 0.25, 0.5, 0.75, 1, 1.5, 2, 5, 7, and 10 mg / L into 10 mL porcelain crucibles respectively, add 50 μg FeCl3 solution, and the following operations are the same as the rock sample analysis steps.

[0047] Example 3

[0048] A field rapid analysis method for trace gold comprises the following steps:

[0049] S1. Dissolving ore: weigh 10g sample into a 125mL conical beaker, add 1g potassium nitrate and then slowly add 20mL 12M hydrochloric acid solution. After the reaction stops, heat to a slight boil for 15min, remove and cool slightly, add 20mL 8M nitric acid solution and continue to heat to a slight boil for about 20min, cool to room temperature, and dilute to 100mL with purified water.

[0050] S2, enrichment: add 5 drops of polypropylene imine, let stand for 20 minutes, separate 5 ml of the liquid into a beaker, dilute to 100 mL with 10 vol% hydrochloric acid, slowly drip through the adsorption column equipped with thiol cotton at a speed of 15 d / min, take out the thiol cotton, wash it once with hydrochloric acid and then wash it three times with pure water;

[0051] S3. Secondary ore dissolution after ashing: squeeze the washed mercapto cotton dry and put it into a porcelain crucible, heat it to 800℃ for ashing, take it out and add 1mL 15% hydrochloric acid, evaporate it in a water bath.

[0052] S4. After evaporation, add 2 mL of masking agent and 5 mL of 5 vol% hydrochloric acid, transfer to a colorimetric tube, then add 5 drops of 10% urea and 5 drops of color developer, shake vigorously to mix evenly, let stand to separate layers, and then compare the color with the standard series visually.

[0053] The masking agent is prepared in advance in the laboratory and can be stored for a certain period of time in the field. The preparation method is as follows: weigh 21g malic acid, 7g glutaric acid, and 7g ethylenediaminetetraacetic acid (EDTA) in a 500mL beaker, add 10mL ammonia water, add 200mL distilled water, stir well to dissolve, transfer to a clean container, and adjust the pH to 3.5-4 with acetic acid-sodium acetate buffer.

[0054] How to make standard color scale:

[0055] Pipette Au standard solutions containing 0, 0.1, 0.25, 0.5, 0.75, 1, 1.5, 2, 5, 7, and 10 mg / L into 10 mL porcelain crucibles respectively, add 50 μg FeCl3 solution, and the following operations are the same as the rock sample analysis steps.

[0056] Comparative Example 1

[0057] This example provides a field rapid analysis method for trace gold, and its steps are basically the same as those in Implementation 1, except that potassium nitrate is not added in step S1, and other operations are consistent with Example 1.

[0058] A field rapid analysis method for trace gold comprises the following steps:

[0059] S1. Dissolving ore: Weigh 10g rock mineral sample into a 125mL conical beaker, slowly add 20mL 12M hydrochloric acid solution, heat to a slight boil for 20min after the reaction stops, remove and cool slightly, add 15mL 8M nitric acid solution and continue to heat to a slight boil for about 20min, cool to room temperature, and dilute to 100mL with purified water.

[0060] S2, enrichment: add 5 drops of polypropylene imine, let stand for 20 minutes, separate 5 ml of the liquid into a beaker, dilute to 100 mL with 10 vol% hydrochloric acid, slowly drip through the adsorption column equipped with thiol cotton at a speed of 20 d / min, take out the thiol cotton, wash it once with hydrochloric acid and then wash it three times with pure water;

[0061] S3. Secondary ore dissolution after ashing: squeeze the washed mercapto cotton dry and put it into a porcelain crucible, heat it to 800℃ for ashing, take it out and add 1mL 15% hydrochloric acid, evaporate it in a water bath.

[0062] S4. After evaporation, add 2 mL of masking agent and 5 mL of 5 vol% hydrochloric acid, transfer to a colorimetric tube, then add 5 drops of 10% urea and 5 drops of color developer, shake vigorously to mix evenly, let stand to separate layers, and then compare the color with the standard series visually.

[0063] The masking agent is prepared in the laboratory in advance and can be stored for a certain period of time in the field. The preparation method is as follows: weigh 15g malic acid, 10g glutaric acid, and 10g ethylenediaminetetraacetic acid (EDTA) in a 500mL beaker, add 10mL ammonia water, add 200mL distilled water, stir well to dissolve, transfer to a clean container, and adjust the pH to 3.5-4 with acetic acid-sodium acetate buffer.

[0064] How to make standard color scale:

[0065] Pipette Au standard solutions containing 0, 0.1, 0.25, 0.5, 0.75, 1, 1.5, 2, 5, 7, and 10 mg / L into 10 mL porcelain crucibles respectively, add 50 μg FeCl3 solution, and the following operations are the same as the rock sample analysis steps.

[0066] Comparative Example 2

[0067] This example provides a field rapid analysis method for trace gold, and its steps are basically the same as those in Implementation 1, except that in step S2, polypropylene imine is not added to the mineral solution, and other operations are consistent with Example 1.

[0068] A field rapid analysis method for trace gold comprises the following steps:

[0069] S1. Ore dissolution: weigh 10g of rock mineral sample into a 125mL conical beaker, add 1g of potassium nitrate powder and slowly add 20mL of 12M hydrochloric acid solution. After the reaction stops, heat to a slight boil for 20min, remove and cool slightly, add 15mL of 8M nitric acid solution and continue to heat to a slight boil for about 20min, cool to room temperature, and dilute to 100mL with purified water.

[0070] S2, enrichment: take 5 ml in a beaker, dilute to 100 mL with 10 vol% hydrochloric acid, slowly drip through an adsorption column filled with thiol cotton at a rate of 20 d / min, take out the thiol cotton, wash it once with hydrochloric acid and then wash it three times with pure water;

[0071] S3. Secondary ore dissolution after ashing: squeeze the washed mercapto cotton dry and put it into a porcelain crucible, heat it to 800℃ for ashing, take it out and add 1mL 15% hydrochloric acid, evaporate it in a water bath.

[0072] S4. After evaporation, add 2 mL of masking agent and 5 mL of 5 vol% hydrochloric acid, transfer to a colorimetric tube, then add 5 drops of 10% urea and 5 drops of color developer, shake vigorously to mix evenly, let stand to separate layers, and then compare the color with the standard series visually.

[0073] The masking agent is prepared in the laboratory in advance and can be stored for a certain period of time in the field. The preparation method is as follows: weigh 15g malic acid, 10g glutaric acid, and 10g ethylenediaminetetraacetic acid (EDTA) in a 500mL beaker, add 10mL ammonia water, add 200mL distilled water, stir well to dissolve, transfer to a clean container, and adjust the pH to 3.5-4 with acetic acid-sodium acetate buffer.

[0074] How to make standard color scale:

[0075] Pipette Au standard solutions containing 0, 0.1, 0.25, 0.5, 0.75, 1, 1.5, 2, 5, 7, and 10 mg / L into 10 mL porcelain crucibles respectively, add 50 μg FeCl3 solution, and the following operations are the same as the rock sample analysis steps.

[0076] Comparative Example 3

[0077] This example provides a field rapid analysis method for trace gold, and its steps are basically the same as those in Implementation 1, except that polypropylene imine in step S2 is replaced by polyvinyl alcohol, and other operations are consistent with Example 1.

[0078] A field rapid analysis method for trace gold comprises the following steps:

[0079] S1. Ore dissolution: weigh 10g of rock mineral sample into a 125mL conical beaker, add 1g of potassium nitrate powder and slowly add 20mL of 12M hydrochloric acid solution. After the reaction stops, heat to a slight boil for 20min, remove and cool slightly, add 15mL of 8M nitric acid solution and continue to heat to a slight boil for about 20min, cool to room temperature, and dilute to 100mL with purified water.

[0080] S2, enrichment: add 5 drops of polyvinyl alcohol, let stand for 20 minutes, separate 5 ml of the liquid into a beaker, dilute to 100 mL with 10 vol% hydrochloric acid, slowly drip through the adsorption column equipped with thiol cotton at a speed of 20 d / min, take out the thiol cotton, wash it once with hydrochloric acid and then wash it three times with pure water;

[0081] S3. Secondary ore dissolution after ashing: squeeze the washed mercapto cotton dry and put it into a porcelain crucible, heat it to 800℃ for ashing, take it out and add 1mL 15% hydrochloric acid, evaporate it in a water bath.

[0082] S4. After evaporation, add 2 mL of masking agent and 5 mL of 5 vol% hydrochloric acid, transfer to a colorimetric tube, then add 5 drops of 10% urea and 5 drops of color developer, shake vigorously to mix evenly, let stand to separate layers, and then compare the color with the standard series visually.

[0083] The masking agent is prepared in the laboratory in advance and can be stored for a certain period of time in the field. The preparation method is as follows: weigh 15g malic acid, 10g glutaric acid, and 10g ethylenediaminetetraacetic acid (EDTA) in a 500mL beaker, add 10mL ammonia water, add 200mL distilled water, stir well to dissolve, transfer to a clean container, and adjust the pH to 3.5-4 with acetic acid-sodium acetate buffer.

[0084] How to make standard color scale:

[0085] Pipette Au standard solutions containing 0, 0.1, 0.25, 0.5, 0.75, 1, 1.5, 2, 5, 7, and 10 mg / L into 10 mL porcelain crucibles respectively, add 50 μg FeCl3 solution, and the following operations are the same as the rock sample analysis steps.

[0086] Comparative Example 4

[0087] This example provides a method for rapid field analysis of trace gold, and its steps are basically the same as those in Implementation 1, except that the mass ratio of malic acid, glutaric acid, and ethylenediaminetetraacetic acid in the masking agent in step S4 is 1:1.5:1, and other operations are consistent with Example 1.

[0088] Preparation method of the masking agent: weigh 10g malic acid, 15g glutaric acid, and 10g ethylenediaminetetraacetic acid (EDTA) in a 500mL beaker, add 10mL ammonia water, add 200mL distilled water, stir well to dissolve, transfer to a clean container and adjust the pH to 3.5-4 with acetic acid-sodium acetate buffer.

[0089] Comparative Example 5

[0090] This example provides a method for rapid field analysis of trace gold, and its steps are basically the same as those of Implementation 1, except that malic acid is replaced by citric acid in the masking agent in step S4, and other operations are consistent with Example 1.

[0091] Preparation method of the masking agent: weigh 15g citric acid, 10g glutaric acid, and 10g ethylenediaminetetraacetic acid (EDTA) in a 500mL beaker, add 10mL ammonia water, add 200mL distilled water, stir well to dissolve, transfer to a clean container and adjust the pH to 3.5-4 with acetic acid-sodium acetate buffer.

[0092] Test Example 1

[0093] The gold content in 5 different ore samples was determined by the field rapid analysis method for trace gold in Example 1 and by laboratory graphite furnace atomic absorption spectrometry, and the results were compared. The results are shown in Table 1.

[0094] Table 1

[0095]

[0096] As shown in Table 1, the sensitivity of the field rapid analysis method for trace gold in Example 1 of the present invention for determining the gold content in rocks and minerals can reach 0.1×10 -6 When the gold content is greater than 0.1×10 -6 When the field rapid analysis method for trace gold in Example 1 of the present invention is used to compare the results with the graphite furnace atomic absorption spectrometry, the relative deviation is within 20%, which can meet the demand for gold content in field geological mineral samples.

[0097] Test Example 2

[0098] The gold content in the same rock and mineral sample was measured by the field rapid analysis method for trace gold in Examples 1 to 3 and Comparative Examples 1 to 5 and by the laboratory graphite furnace atomic absorption spectrometry, and the results were compared. The results are shown in Table 2.

[0099] Table 2

[0100]

[0101] As shown in Table 1, the field rapid analysis method for trace gold described in Examples 1 to 3 of the present invention is closer to the laboratory chemical quantitative analysis results for the determination of gold content in rocks and ores, and the error is small. Comparison of the results of Example 1 with those of Example 1 shows that the analysis results of the gold ore samples dissolved in hydrochloric acid and nitric acid are smaller than those of the gold ore samples dissolved in hydrochloric acid, potassium nitrate and nitric acid. This is because potassium nitrate is mainly used as an oxidant during the dissolution process, which can promote the oxidation reaction of some metal oxides or sulfides in the minerals and improve the efficiency of the dissolution process; the large test error of Example 2 is because the mineral solution contains a certain amount of soluble silicates, and when the mercapto cotton adsorbs gold, the determination result will be low, and polypropylene imine has multiple amino (-NH2) functional groups, which can react with silicate ions (SiO3 2-) interaction, effectively fixing silicate in the structure of polypropylene imine to form a stable complex or colloidal structure, so polypropylene imine is added before adsorption to condense silicate and remove it by filtration, and polyethylene oxide does not affect the adsorption of gold; Comparative Examples 4 and 5 are compared with Example 1, showing that the masking agent obtained by configuring malic acid, glutaric acid, and ethylenediaminetetraacetic acid in a certain proportion can better reduce the interference of other metal ions on the gold analysis results.

[0102] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A field rapid analysis method for trace gold, characterized in that: The following steps are involved: S1. Dissolving ore: taking a rock mineral sample into a container, adding a dissolving agent, heating to a slight boiling point to dissolve the ore at high temperature, and obtaining a mineral solution; the dissolving agent is a hydrochloric acid solution, potassium nitrate powder and a nitric acid solution; S2, enrichment: add polypropylene imine to the mineral solution, let it stand, take the clear solution and dilute it with hydrochloric acid, slowly drip it through the adsorption column equipped with thiol cotton, take out the thiol cotton and wash it with solvent; S3, secondary ore dissolution after ashing: squeeze the washed mercapto cotton dry, heat it until ashing, add hydrochloric acid, and evaporate it in a water bath; S4. Determination: After evaporation, add masking agent and hydrochloric acid, transfer to a colorimetric tube, add urea and TMK color developer, mix well, let stand, and compare color with the standard series visually.

2. A field rapid analysis method for trace gold according to claim 1, characterized in that: The S1 ore dissolution is specifically as follows: taking a rock mineral sample in a conical beaker, adding potassium nitrate powder and then adding hydrochloric acid solution and stirring evenly, heating to a slight boil for 15 to 20 minutes after the reaction stops, cooling, then adding nitric acid solution and continuing to heat to a slight boil for about 15 to 20 minutes, cooling to room temperature, and diluting with purified water.

3. A field rapid analysis method for trace gold according to claim 2, characterized in that: The mass ratio of the potassium nitrate powder to the mineral sample is 1:10; the mass volume ratio of the mineral sample to the hydrochloric acid solution is 1g:2-3mL; the mass volume ratio of the mineral sample to the nitric acid solution is 1g:1-2mL.

4. A field rapid analysis method for trace gold according to claim 2, characterized in that: The mass volume ratio of the mineral sample to the solution diluted with pure water is 1 g: 10-15 mL.

5. A field rapid analysis method for trace gold according to claim 1, characterized in that: The flow rate of the slow dripping through the adsorption column equipped with mercapto cotton is 15 to 20 d / min.

6. A field rapid analysis method for trace gold according to claim 1, characterized in that: The method of taking out the mercapto cotton and washing it with a solvent specifically comprises taking out the mercapto cotton and washing it once with hydrochloric acid and then washing it three times with pure water.

7. A field rapid analysis method for trace gold according to claim 1, characterized in that: The masking agent is a mixture of malic acid, glutaric acid and ethylenediaminetetraacetic acid.

8. A field rapid analysis method for trace gold according to claim 7, characterized in that: The mass ratio of the malic acid, glutaric acid and ethylenediaminetetraacetic acid is 1-3:1:

1.

9. A field rapid analysis method for trace gold according to claim 1, characterized in that: The preparation method of the masking agent is as follows: weigh glutaric acid, malic acid, and ethylenediaminetetraacetic acid (EDTA) in a container, add ammonia water and distilled water, stir and dissolve, transfer into a clean container, and adjust the pH to 3.5-4 with acetic acid-sodium acetate buffer; the masking agent is prepared in advance in the laboratory for use.

10. A field rapid analysis method for trace gold according to claim 1, characterized in that: The preparation method of the color developer is as follows: dissolving thiomikler's ketone (TMK) in anhydrous ethanol until saturated, and taking the upper clear liquid for use.

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