Method for improving accuracy of determination of silver content in gold-loaded carbon by flame atomic absorption spectrometry

Abstract

This invention relates to the field of gold-loaded carbon silver content testing technology, specifically disclosing a method for improving the accuracy of determining the silver content of gold-loaded carbon using flame atomic absorption spectrometry. The method includes the following steps: preheating and improving the gold-loaded carbon, then adding it to a rare earth compounding solution (4-5 times the total volume of the preheated and improved gold-loaded carbon) for oscillation modification; after modification, washing and drying. This invention uses preheating to optimize the activity of the gold-loaded carbon raw material, facilitating subsequent oscillation modification in the rare earth compounding solution. The oscillation optimization of the rare earth compounding solution activates the raw material of the test product, promoting complete carbon removal during heating to a smokeless state in a concentrated nitric acid water bath and crucible. This optimizes the accuracy of silver measurement. Finally, flame atomic absorption spectrometry is used for determination, and a standard curve is established, thus optimizing the measurement method for the accurate silver content of gold-loaded carbon.

Description

Technical Field

[0001] This invention relates to the field of spectroscopic determination of gold-loaded carbon and silver, specifically to a method for improving the accuracy of flame atomic absorption spectrometry in determining the content of gold-loaded carbon and silver. Background Technology

[0002] Gold-loaded carbon refers to activated carbon that adsorbs gold from the liquid phase and contains a certain amount of gold. It is both a product of gold extraction from gold mines and a raw material for gold smelting. Currently, the main method for recovering gold and silver from gold mines is the activated carbon adsorption process. Because silver is a by-product of gold mining, the activated carbon adsorption process can adsorb not only gold but also other precious metals such as silver. Silver recovery has high economic value, making it necessary to accurately determine the silver content in gold-loaded carbon.

[0003] The existing flame atomic absorption spectrometry method for determining silver content uses concentrated sulfuric acid and heating, which is simple but has poor accuracy in testing silver content. Therefore, this invention further improves upon it. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the purpose of this invention is to provide a method for improving the accuracy of determining the silver content of gold-loaded carbon by flame atomic absorption spectrometry, so as to solve the problems mentioned in the background art.

[0005] The present invention solves the technical problem by adopting the following technical solution:

[0006] This invention provides a method for improving the accuracy of determining the silver content of gold-loaded carbon using flame atomic absorption spectrometry, comprising the following steps:

[0007] Step 1: First, preheat and improve the gold-loaded carbon, then add it to a rare earth compounding solution with a volume of 4-5 times the total amount of the preheated and improved gold-loaded carbon and shake to modify it. After modification, wash with water and dry.

[0008] Step 2: Add 2-3 times the amount of concentrated nitric acid to the product from Step 1, and then treat it in a water bath at 90-100℃ for 1-2 hours;

[0009] Step 3: Place the product from Step 2 in the conditioning solution and stir to modify it. After stirring, wash with water and filter.

[0010] Step 4: Wash the filtered product from Step 3 with hot nitric acid, then transfer it to a crucible and heat it until it is smokeless. Add concentrated nitric acid and concentrated hydrochloric acid to the crucible. The ratio of crucible product, concentrated nitric acid, and concentrated hydrochloric acid is 1:2:5.

[0011] Step 5: Finally, flame atomic absorption spectrometry is used to determine the standard curve.

[0012] Preferably, the specific operation steps of the preheating improvement treatment are as follows:

[0013] S01: Pre-treat at 110-120℃ for 5-10 min, then raise the temperature to 175-180℃ at a rate of 1-3℃ / min and hold for 2-5 min;

[0014] S02: Then air cool to 85-90℃, hold for 10-20 minutes, and finally cool to room temperature at a rate of 3-5℃ / min.

[0015] Preferably, the specific steps for oscillation modification in the rare earth conditioning solution are as follows:

[0016] S11: Add the rare earth lanthanum sulfate solution to the chitosan solution at a weight ratio of 1:3, then add 3-6% of the total amount of rare earth lanthanum sulfate solution in phosphate buffer solution, and perform primary stirring.

[0017] S12: Then add 2-5% of the total amount of rare earth lanthanum sulfate solution with organic alcohol and 2-5% of the total amount of rare earth lanthanum sulfate solution with silane coupling agent KH560, and perform secondary stirring. After stirring is completed, a rare earth compound solution is obtained.

[0018] S13: Add the thermally modified gold-loaded carbon to a rare earth compounding solution of 4-5 times the total amount of thermally modified gold-loaded carbon and shake to modify it. After the treatment is completed, wash with water and dry.

[0019] Preferably, the chitosan solution has a mass fraction of 4-8%; the phosphate buffer solution has a pH of 5.0; and the rare earth lanthanum sulfate solution has a mass fraction of 3-5%.

[0020] Preferably, the primary stirring process has a rotation speed of 350-450 r / min and a stirring time of 20-30 min; the secondary stirring process has a rotation speed of 650-750 r / min and a stirring time of 45-55 min.

[0021] Preferably, the oscillation power of the oscillation modification treatment is 300-500W, and the oscillation time is 1-2h.

[0022] Preferably, the specific steps of the stirring modification treatment in the conditioning solution are as follows: a 5% yttrium nitrate solution and a 90% ethanol solution are mixed to obtain a conditioning solution, and then the product from step two is placed in the conditioning solution at a weight ratio of 1:5 and stirred at a speed of 450-500 r / min for 20-30 min for modification.

[0023] Preferably, the standard curve is prepared as follows: 0.0, 0.25, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, and 5.0 μg / mL of silver standard solution are respectively transferred to 100 mL volumetric flasks, and diluted to the mark with 20% aqua regia. Under the instrument measurement conditions, the absorbance of the standard series solutions is measured, and a working curve is plotted with absorbance as the ordinate and silver concentration as the abscissa.

[0024] Preferably, the linear equation of the working curve is: γ = 0.003510 + 0.1810x, and the correlation coefficient is: 0.93550.

[0025] Preferably, the instrument includes an MKII-M6 atomic absorption spectrophotometer and a hollow cathode lamp.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] This invention employs preheating improvements to optimize the activity of the gold-loaded carbon raw material, facilitating subsequent oscillation modification in the rare earth compounding solution. Through oscillation optimization in the rare earth compounding solution, the raw material of the test product can be activated. Heating to a smokeless state in a concentrated nitric acid water bath and crucible promotes complete carbon removal, optimizing the accuracy of silver measurement. Finally, flame atomic absorption spectrometry is used to determine the silver content, establishing a standard curve and optimizing the measurement method for accurate gold-loaded carbon silver content. Simultaneously, the stirring modification treatment in the conditioning solution and the oscillation modification in the rare earth compounding solution work synergistically to optimize the measurement accuracy of the product. Furthermore, the elements in the conditioning solution and rare earth compounding solution, after being processed by this invention, are not present in the test product, thus achieving a highly efficient measurement method. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to specific examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The method for improving the accuracy of determining the silver content of gold-loaded carbon using flame atomic absorption spectrometry in this embodiment includes the following steps:

[0030] Step 1: First, preheat and improve the gold-loaded carbon, then add it to a rare earth compounding solution with a volume of 4-5 times the total amount of the preheated and improved gold-loaded carbon and shake to modify it. After modification, wash with water and dry.

[0031] Step 2: Add 2-3 times the amount of concentrated nitric acid to the product from Step 1, and then treat it in a water bath at 90-100℃ for 1-2 hours;

[0032] Step 3: Place the product from Step 2 in the conditioning solution and stir to modify it. After stirring, wash with water and filter.

[0033] Step 4: Wash the filtered product from Step 3 with hot nitric acid, then transfer it to a crucible and heat it until it is smokeless. Add concentrated nitric acid and concentrated hydrochloric acid to the crucible. The ratio of crucible product, concentrated nitric acid, and concentrated hydrochloric acid is 1:2:5.

[0034] Step 5: Finally, flame atomic absorption spectrometry is used to determine the standard curve.

[0035] The specific operation steps of the preheating improvement process in this embodiment are as follows:

[0036] S01: Pre-treat at 110-120℃ for 5-10 min, then raise the temperature to 175-180℃ at a rate of 1-3℃ / min and hold for 2-5 min;

[0037] S02: Then air cool to 85-90℃, hold for 10-20 minutes, and finally cool to room temperature at a rate of 3-5℃ / min.

[0038] The specific steps for vibration modification in the rare earth compounding solution in this embodiment are as follows:

[0039] S11: Add the rare earth lanthanum sulfate solution to the chitosan solution at a weight ratio of 1:3, then add 3-6% of the total amount of rare earth lanthanum sulfate solution in phosphate buffer solution, and perform primary stirring.

[0040] S12: Then add 2-5% of the total amount of rare earth lanthanum sulfate solution with organic alcohol and 2-5% of the total amount of rare earth lanthanum sulfate solution with silane coupling agent KH560, and perform secondary stirring. After stirring is completed, a rare earth compound solution is obtained.

[0041] S13: Add the thermally modified gold-loaded carbon to a rare earth compounding solution of 4-5 times the total amount of thermally modified gold-loaded carbon and shake to modify it. After the treatment is completed, wash with water and dry.

[0042] In this embodiment, the chitosan solution has a mass fraction of 4-8%; the phosphate buffer solution has a pH value of 5.0; and the rare earth lanthanum sulfate solution has a mass fraction of 3-5%.

[0043] In this embodiment, the primary stirring speed is 350-450 r / min and the stirring time is 20-30 min; the secondary stirring speed is 650-750 r / min and the stirring time is 45-55 min.

[0044] In this embodiment, the oscillation power of the oscillation modification treatment is 300-500W, and the oscillation time is 1-2h.

[0045] The specific steps of the stirring modification treatment in the conditioning solution in this embodiment are as follows: a 5% yttrium nitrate solution and a 90% ethanol solution are mixed to obtain a conditioning solution. Then, the product from step two is placed in the conditioning solution at a weight ratio of 1:5 and stirred at a speed of 450-500 r / min for 20-30 min for modification.

[0046] In this embodiment, the standard curve is prepared as follows: 0.0, 0.25, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, and 5.0 μg / mL of silver standard solution are respectively transferred to 100 mL volumetric flasks, and diluted to the mark with 20% aqua regia. Under the instrument's measurement conditions, the absorbance of the standard series solutions is measured. A working curve is plotted with absorbance as the ordinate and silver concentration as the abscissa.

[0047] The linear equation of the working curve in this embodiment is: γ = 0.003510 + 0.1810x, and the correlation coefficient is: 0.93550.

[0048] The instruments used in this embodiment include an MKII-M6 atomic absorption spectrophotometer and a hollow cathode lamp.

[0049] Example 1.

[0050] The method for improving the accuracy of determining the silver content of gold-loaded carbon using flame atomic absorption spectrometry in this embodiment includes the following steps:

[0051] Step 1: First, preheat and improve the gold-loaded carbon, then add it to a rare earth compounding solution with a volume of 4-5 times the total amount of the preheated and improved gold-loaded carbon and shake to modify it. After modification, wash with water and dry.

[0052] Step 2: Add twice the amount of concentrated nitric acid to the product from Step 1, and then treat it in a water bath at 90°C for 1 hour;

[0053] Step 3: Place the product from Step 2 in the conditioning solution and stir to modify it. After stirring, wash with water and filter.

[0054] Step 4: Wash the filtered product from Step 3 with hot nitric acid, then transfer it to a crucible and heat it until it is smokeless. Add concentrated nitric acid and concentrated hydrochloric acid to the crucible. The ratio of crucible product, concentrated nitric acid, and concentrated hydrochloric acid is 1:2:5.

[0055] Step 5: Finally, flame atomic absorption spectrometry is used to determine the standard curve.

[0056] The specific operation steps of the preheating improvement process in this embodiment are as follows:

[0057] S01: Pre-treat at 110-120℃ for 5 min, then raise the temperature to 175℃ at a rate of 1℃ / min and hold for 2 min;

[0058] S02: Then air cool to 85℃, hold for 10 minutes, and finally cool to room temperature at a rate of 3℃ / min.

[0059] The specific steps for vibration modification in the rare earth compounding solution in this embodiment are as follows:

[0060] S11: Add the rare earth lanthanum sulfate solution to the chitosan solution at a weight ratio of 1:3, then add 3-6% of the total amount of rare earth lanthanum sulfate solution in phosphate buffer solution, and perform primary stirring.

[0061] S12: Then add 2-5% of the total amount of rare earth lanthanum sulfate solution with organic alcohol and 2-5% of the total amount of rare earth lanthanum sulfate solution with silane coupling agent KH560, and perform secondary stirring. After stirring is completed, a rare earth compound solution is obtained.

[0062] S13: Add the thermally modified gold-loaded carbon to a rare earth compounding solution of 4-5 times the total amount of thermally modified gold-loaded carbon and shake to modify it. After the treatment is completed, wash with water and dry.

[0063] In this embodiment, the chitosan solution has a mass fraction of 4-8%; the phosphate buffer solution has a pH value of 5.0; and the rare earth lanthanum sulfate solution has a mass fraction of 3-5%.

[0064] In this embodiment, the primary stirring speed is 350-450 r / min and the stirring time is 20-30 min; the secondary stirring speed is 650-750 r / min and the stirring time is 45-55 min.

[0065] In this embodiment, the oscillation power of the oscillation modification treatment is 300-500W, and the oscillation time is 1-2h.

[0066] The specific steps of the stirring modification treatment in the conditioning solution in this embodiment are as follows: a 5% yttrium nitrate solution and a 90% ethanol solution are mixed to obtain a conditioning solution. Then, the product from step two is placed in the conditioning solution at a weight ratio of 1:5 and stirred at a speed of 450-500 r / min for 20-30 min for modification.

[0067] In this embodiment, the standard curve is prepared as follows: 0.0, 0.25, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, and 5.0 μg / mL of silver standard solution are respectively transferred to 100 mL volumetric flasks, and diluted to the mark with 20% aqua regia. Under the instrument's measurement conditions, the absorbance of the standard series solutions is measured. A working curve is plotted with absorbance as the ordinate and silver concentration as the abscissa.

[0068] The linear equation of the working curve in this embodiment is: γ = 0.003510 + 0.1810x, and the correlation coefficient is: 0.93550.

[0069] The instruments used in this embodiment include an MKII-M6 atomic absorption spectrophotometer and a hollow cathode lamp.

[0070] Example 2.

[0071] The method for improving the accuracy of determining the silver content of gold-loaded carbon using flame atomic absorption spectrometry in this embodiment includes the following steps:

[0072] Step 1: First, preheat and improve the gold-loaded carbon, then add it to a rare earth compounding solution with a volume of 5 times the total amount of the preheated and improved gold-loaded carbon and shake to modify it. After the modification is completed, wash with water and dry.

[0073] Step 2: Add 3 times the amount of concentrated nitric acid to the product from Step 1, and then treat it in a water bath at 100°C for 2 hours;

[0074] Step 3: Place the product from Step 2 in the conditioning solution and stir to modify it. After stirring, wash with water and filter.

[0075] Step 4: Wash the filtered product from Step 3 with hot nitric acid, then transfer it to a crucible and heat it until it is smokeless. Add concentrated nitric acid and concentrated hydrochloric acid to the crucible. The ratio of crucible product, concentrated nitric acid, and concentrated hydrochloric acid is 1:2:5.

[0076] Step 5: Finally, flame atomic absorption spectrometry is used to determine the standard curve.

[0077] The specific operation steps of the preheating improvement process in this embodiment are as follows:

[0078] S01: Pre-treat at 120℃ for 10 min, then raise the temperature to 180℃ at a rate of 3℃ / min and hold for 5 min;

[0079] S02: Then air cool to 90℃, hold for 20 minutes, and finally cool to room temperature at a rate of 5℃ / min.

[0080] The specific steps for vibration modification in the rare earth compounding solution in this embodiment are as follows:

[0081] S11: Add the rare earth lanthanum sulfate solution to the chitosan solution at a weight ratio of 1:3, then add 6% of the total amount of rare earth lanthanum sulfate solution in phosphate buffer solution, and perform primary stirring.

[0082] S12: Then add 5% of the total amount of rare earth lanthanum sulfate solution with organic alcohol and 5% of the total amount of rare earth lanthanum sulfate solution with silane coupling agent KH560, and perform secondary stirring. After stirring, a rare earth compound solution is obtained.

[0083] S13: Add the thermally modified gold-loaded carbon to a rare earth compounding solution with a volume of 5 times the total amount of thermally modified gold-loaded carbon and shake to modify it. After the treatment is completed, wash with water and dry.

[0084] In this embodiment, the chitosan solution has a mass fraction of 8%; the phosphate buffer solution has a pH value of 5.0; and the rare earth lanthanum sulfate solution has a mass fraction of 5%.

[0085] In this embodiment, the primary stirring speed is 450 r / min and the stirring time is 30 min; the secondary stirring speed is 750 r / min and the stirring time is 55 min.

[0086] In this embodiment, the oscillation power of the oscillation modification treatment is 500W, and the oscillation time is 2h.

[0087] The specific steps of the stirring modification treatment in the conditioning solution in this embodiment are as follows: a 5% yttrium nitrate solution and a 90% ethanol solution are mixed to obtain a conditioning solution. Then, the product from step two is placed in the conditioning solution at a weight ratio of 1:5 and stirred at 500 r / min for 30 min for modification.

[0088] In this embodiment, the standard curve is prepared as follows: 0.0, 0.25, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, and 5.0 μg / mL of silver standard solution are respectively transferred to 100 mL volumetric flasks, and diluted to the mark with 20% aqua regia. Under the instrument's measurement conditions, the absorbance of the standard series solutions is measured. A working curve is plotted with absorbance as the ordinate and silver concentration as the abscissa.

[0089] The linear equation of the working curve in this embodiment is: γ = 0.003510 + 0.1810x, and the correlation coefficient is: 0.93550.

[0090] The instruments used in this embodiment include an MKII-M6 atomic absorption spectrophotometer and a hollow cathode lamp.

[0091] Example 3.

[0092] The method for improving the accuracy of determining the silver content of gold-loaded carbon using flame atomic absorption spectrometry in this embodiment includes the following steps:

[0093] Step 1: First, preheat and improve the gold-loaded carbon, then add it to a rare earth compounding solution with a total volume of 4.5 times that of the preheated and improved gold-loaded carbon and shake to modify it. After modification, wash with water and dry.

[0094] Step 2: Add the product from Step 1 to 2.5 times the amount of concentrated nitric acid, and then treat it in a water bath at 95°C for 1.5 hours;

[0095] Step 3: Place the product from Step 2 in the conditioning solution and stir to modify it. After stirring, wash with water and filter.

[0096] Step 4: Wash the filtered product from Step 3 with hot nitric acid, then transfer it to a crucible and heat it until it is smokeless. Add concentrated nitric acid and concentrated hydrochloric acid to the crucible. The ratio of crucible product, concentrated nitric acid, and concentrated hydrochloric acid is 1:2:5.

[0097] Step 5: Finally, flame atomic absorption spectrometry is used to determine the standard curve.

[0098] The specific operation steps of the preheating improvement process in this embodiment are as follows:

[0099] S01: Pre-treat at 115℃ for 7.5 min, then heat to 178℃ at a rate of 2℃ / min and hold for 3.5 min;

[0100] S02: Then air cool to 88℃, hold for 15 minutes, and finally cool to room temperature at a rate of 4℃ / min.

[0101] The specific steps for vibration modification in the rare earth compounding solution in this embodiment are as follows:

[0102] S11: Add the rare earth lanthanum sulfate solution to the chitosan solution at a weight ratio of 1:3, and then add 4.5% of the total amount of rare earth lanthanum sulfate solution in phosphate buffer solution, followed by primary stirring.

[0103] S12: Then add 3.5% of the total amount of rare earth lanthanum sulfate solution with organic alcohol and 3.5% of the total amount of rare earth lanthanum sulfate solution with silane coupling agent KH560, and perform secondary stirring. After stirring, a rare earth compound solution is obtained.

[0104] S13: Add the thermally modified gold-loaded carbon to a rare earth compounding solution with a volume of 4.5 times the total amount of thermally modified gold-loaded carbon and shake to modify it. After the treatment is completed, wash with water and dry.

[0105] In this embodiment, the chitosan solution has a mass fraction of 6%; the phosphate buffer solution has a pH value of 5.0; and the rare earth lanthanum sulfate solution has a mass fraction of 4%.

[0106] In this embodiment, the primary stirring speed is 400 r / min and the stirring time is 25 min; the secondary stirring speed is 700 r / min and the stirring time is 50 min.

[0107] In this embodiment, the oscillation power of the oscillation modification treatment is 400W, and the oscillation time is 1.5h.

[0108] The specific steps of the stirring modification treatment in the conditioning solution in this embodiment are as follows: a 5% yttrium nitrate solution and a 90% ethanol solution are mixed to obtain a conditioning solution. Then, the product from step two is placed in the conditioning solution at a weight ratio of 1:5 and stirred at 470 r / min for 25 min for modification.

[0109] In this embodiment, the standard curve is prepared as follows: 0.0, 0.25, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, and 5.0 μg / mL of silver standard solution are respectively transferred to 100 mL volumetric flasks, and diluted to the mark with 20% aqua regia. Under the instrument's measurement conditions, the absorbance of the standard series solutions is measured. A working curve is plotted with absorbance as the ordinate and silver concentration as the abscissa.

[0110] The linear equation of the working curve in this embodiment is: γ = 0.003510 + 0.1810x, and the correlation coefficient is: 0.93550.

[0111] The instruments used in this embodiment include an MKII-M6 atomic absorption spectrophotometer and a hollow cathode lamp.

[0112] Example 4

[0113] The method for improving the accuracy of determining the silver content of gold-loaded carbon using flame atomic absorption spectrometry in this embodiment includes the following steps:

[0114] Step 1: First, preheat and improve the gold-loaded carbon, then add it to a rare earth compounding solution with a volume of 4 times the total amount of the preheated and improved gold-loaded carbon and shake to modify it. After the modification is completed, wash with water and dry.

[0115] Step 2: Add the product from Step 1 to 2.2 times the volume of concentrated nitric acid, and then treat it in a water bath at 92°C for 1.2 hours;

[0116] Step 3: Place the product from Step 2 in the conditioning solution and stir to modify it. After stirring, wash with water and filter.

[0117] Step 4: Wash the filtered product from Step 3 with hot nitric acid, then transfer it to a crucible and heat it until it is smokeless. Add concentrated nitric acid and concentrated hydrochloric acid to the crucible. The ratio of crucible product, concentrated nitric acid, and concentrated hydrochloric acid is 1:2:5.

[0118] Step 5: Finally, flame atomic absorption spectrometry is used to determine the standard curve.

[0119] The specific operation steps of the preheating improvement process in this embodiment are as follows:

[0120] S01: Pre-treat at 112℃ for 6 min, then heat to 178℃ at a rate of 2℃ / min and hold for 3 min;

[0121] S02: Then air cool to 87℃, hold for 12 minutes, and finally cool to room temperature at a rate of 4℃ / min.

[0122] The specific steps for vibration modification in the rare earth compounding solution in this embodiment are as follows:

[0123] S11: Add the rare earth lanthanum sulfate solution to the chitosan solution at a weight ratio of 1:3, then add 4% of the total amount of rare earth lanthanum sulfate solution in phosphate buffer solution, and perform primary stirring.

[0124] S12: Then add 3% of the total amount of rare earth lanthanum sulfate solution with organic alcohol and 3% of the total amount of rare earth lanthanum sulfate solution with silane coupling agent KH560, and perform secondary stirring. After stirring, a rare earth compound solution is obtained.

[0125] S13: Add the thermally modified gold-loaded carbon to a rare earth compounding solution with a volume of 4 times the total amount of thermally modified gold-loaded carbon and shake to modify it. After the treatment is completed, wash with water and dry.

[0126] In this embodiment, the chitosan solution has a mass fraction of 5%; the phosphate buffer solution has a pH value of 5.0; the rare earth lanthanum sulfate solution has a mass fraction of 4%; and the organic alcohol is ethylene glycol.

[0127] In this embodiment, the primary stirring speed is 360 r / min and the stirring time is 22 min; the secondary stirring speed is 680 r / min and the stirring time is 50 min.

[0128] In this embodiment, the oscillation power of the oscillation modification treatment is 400W, and the oscillation time is 1.2h.

[0129] The specific steps of the stirring modification treatment in the conditioning solution in this embodiment are as follows: a 5% yttrium nitrate solution and a 90% ethanol solution are mixed to obtain a conditioning solution. Then, the product from step two is placed in the conditioning solution at a weight ratio of 1:5 and stirred for 22 minutes at a speed of 460 r / min.

[0130] In this embodiment, the standard curve is prepared as follows: 0.0, 0.25, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, and 5.0 μg / mL of silver standard solution are respectively transferred to 100 mL volumetric flasks, and diluted to the mark with 20% aqua regia. Under the instrument's measurement conditions, the absorbance of the standard series solutions is measured. A working curve is plotted with absorbance as the ordinate and silver concentration as the abscissa.

[0131] The linear equation of the working curve in this embodiment is: γ = 0.003510 + 0.1810x, and the correlation coefficient is: 0.93550.

[0132] The instruments used in this embodiment include an MKII-M6 atomic absorption spectrophotometer and a hollow cathode lamp.

[0133] Comparative Example 1.

[0134] Unlike Example 3, no preheating improvement treatment was used.

[0135] Comparative Example 2.

[0136] Unlike Example 3, this method did not employ oscillation modification in a rare earth compounding solution.

[0137] Comparative Example 3.

[0138] Unlike Example 3, no organic alcohol was added in the preparation of the rare earth compounding solution.

[0139] Comparative Example 4.

[0140] Unlike Example 3, no silane coupling agent KH560 was added in the preparation of the rare earth complexation solution.

[0141] Comparative Example 5.

[0142] Unlike Example 3, no stirring modification treatment was used in the conditioning liquid.

[0143] Comparative Example 6.

[0144] Unlike Example 3, yttrium nitrate solution was not used in the preparation of the conditioning solution.

[0145] The products from Examples 1-4 and Comparative Examples 1-6 were subjected to performance tests, and the test results are as follows.

[0146] Example 1 0.32 Example 2 0.34 Example 3 0.31 Example 4 0.33 Comparative Example 1 0.87 Comparative Example 2 1.05 Comparative Example 3 0.66 Comparative Example 4 0.54 Comparative Example 5 0.95 Comparative Example 6 0.57

[0147] As can be seen from Comparative Examples 1-6 and Examples 1-4;

[0148] The product in Example 3 has excellent RSD, with a relative standard deviation as low as 0.31%, and has precise detection efficiency;

[0149] As can be seen from Comparative Examples 1-6 and Example 3, the performance of the product deteriorated significantly because the present invention did not employ preheating improvement treatment, oscillation modification in rare earth compounding solution, or stirring modification in conditioning solution. Furthermore, the absence of organic alcohol and silane coupling agent KH560 in the preparation of rare earth compounding solution, as well as the absence of yttrium nitrate solution in the preparation of conditioning solution, all contributed to a decline in the detection performance of the product. Only when the conditioning solution and rare earth compounding solution prepared by the method of the present invention work together in coordination and synergistic effect can the detection performance of the product be most accurate.

[0150] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0151] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for improving the accuracy of determining the silver content of gold-loaded carbon using flame atomic absorption spectrometry, characterized in that, Includes the following steps: Step 1: First, preheat and improve the gold-loaded carbon, then add it to a rare earth compounding solution with a volume of 4-5 times the total amount of the preheated and improved gold-loaded carbon and shake to modify it. After modification, wash with water and dry. The specific steps for the oscillation modification in the rare earth compounding solution are as follows: S11: Add the rare earth lanthanum sulfate solution to the chitosan solution at a weight ratio of 1:3, then add 3-6% of the total amount of rare earth lanthanum sulfate solution in phosphate buffer solution, and perform primary stirring. S12: Then add 2-5% of the total amount of rare earth lanthanum sulfate solution with organic alcohol and 2-5% of the total amount of rare earth lanthanum sulfate solution with silane coupling agent KH560, and perform secondary stirring. After stirring, a rare earth compound solution is obtained. S13: Add the thermally modified gold-loaded carbon to a rare earth compounding solution of 4-5 times the total amount of thermally modified gold-loaded carbon and shake to modify it. After the treatment is completed, wash with water and dry. Step 2: Add the product from Step 1 to 2-3 times the volume of concentrated nitric acid, and then treat it in a water bath at 90-100℃ for 1-2 hours; Step 3: Place the product from Step 2 in the conditioning solution and stir to modify it. After stirring, wash with water and filter. Step 4: Wash the filtered product from Step 3 with hot nitric acid, then transfer it to a crucible and heat it until it is smokeless. Add concentrated nitric acid and concentrated hydrochloric acid to the crucible. The ratio of crucible product, concentrated nitric acid, and concentrated hydrochloric acid is 1:2:

5. Step 5: Finally, flame atomic absorption spectrometry is used to determine the standard curve.

2. The method for improving the accuracy of determining the silver content of gold-loaded carbon by flame atomic absorption spectrometry according to claim 1, characterized in that, The specific steps of the preheating improvement treatment are as follows: S01: Pre-treat at 110-120℃ for 5-10 min, then raise the temperature to 175-180℃ at a rate of 1-3℃ / min and hold for 2-5 min; S02: Then air cool to 85-90℃, hold for 10-20 minutes, and finally cool to room temperature at a rate of 3-5℃ / min.

3. The method for improving the accuracy of determining the silver content of gold-loaded carbon by flame atomic absorption spectrometry according to claim 1, characterized in that, The chitosan solution has a mass fraction of 4-8%; the phosphate buffer solution has a pH of 5.0; and the rare earth lanthanum sulfate solution has a mass fraction of 3-5%.

4. The method for improving the accuracy of determining the silver content of gold-loaded carbon by flame atomic absorption spectrometry according to claim 1, characterized in that, The primary stirring process involves a stirring speed of 350-450 r / min and a stirring time of 20-30 min; the secondary stirring process involves a stirring speed of 650-750 r / min and a stirring time of 45-55 min.

5. The method for improving the accuracy of determining the silver content of gold-loaded carbon by flame atomic absorption spectrometry according to claim 1, characterized in that, The oscillation power of the oscillation modification treatment is 300-500W, and the oscillation time is 1-2h.

6. The method for improving the accuracy of determining the silver content of gold-loaded carbon by flame atomic absorption spectrometry according to claim 1, characterized in that, The specific steps for the stirring modification treatment in the conditioning solution are as follows: a 5% yttrium nitrate solution and a 90% ethanol solution are mixed to obtain a conditioning solution. Then, the product from step two is placed in the conditioning solution at a weight ratio of 1:5 and stirred at a speed of 450-500 r / min for 20-30 min for modification.

7. The method for improving the accuracy of determining the silver content of gold-loaded carbon by flame atomic absorption spectrometry according to claim 1, characterized in that, The standard curve was prepared as follows: 0.0, 0.25, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, and 5.0 μg / mL of silver standard solution were transferred to 100 mL volumetric flasks, respectively, and diluted to the mark with 20% aqua regia. Under the instrument's measurement conditions, the absorbance of the standard series solutions was measured. The working curve was plotted with absorbance as the ordinate and silver concentration as the abscissa.

8. The method for improving the accuracy of determining the silver content of gold-loaded carbon by flame atomic absorption spectrometry according to claim 7, characterized in that, The linear equation of the working curve is: γ = 0.003510 + 0.1810x, and the correlation coefficient is: 0.93550.

9. The method for improving the accuracy of determining the silver content of gold-loaded carbon by flame atomic absorption spectrometry according to claim 7, characterized in that, The instruments used for measurement include the MKII-M6 atomic absorption spectrophotometer and a hollow cathode lamp.