A high-temperature fusion digestion reagent and method, and a chemical sample analysis method

Abstract

This invention provides a high-temperature melting digestion reagent and method, and a chemical sample analysis method, belonging to the field of chemical analysis technology. The high-temperature melting digestion reagent includes a first composition, a second composition, and a third composition, with a mass ratio of (1-5):(20-80):(20-50). The first composition includes an internal standard reagent and a first foaming agent in a mass ratio of (1-5):(1-3). The second composition includes a strong oxidant, a weak basic oxidant, and a thermally decomposing gas-generating agent in a mass ratio of (85-95):(7-12):(0.6-1.2). The third composition includes a weak basic oxidant, a strong oxidant, and a second foaming agent in a mass ratio of (27-35):(60-70):(0.5-1.2). This invention improves the efficiency of high-temperature melting and avoids the problem of sample ejection affecting the accuracy of detection.

Description

Technical Field

[0001] This invention relates to the field of chemical analysis technology, and more specifically, to a high-temperature melting digestion reagent and method, and a chemical sample analysis method. Background Technology

[0002] Chemical analysis samples of inorganic materials such as rocks, minerals, metals, and alloys require a digestion process to uniformly dissolve the analyte components in a solution before subsequent analysis and measurement. High-temperature melting digestion is a method that rapidly melts the chemical analysis sample with a solid solvent to obtain a eutectic mixture of the chemical analysis sample and the solid flux, which is then used to prepare a solution.

[0003] Currently, commonly used reagents in high-temperature melting digestion processes include sodium carbonate, sodium carbonate + boric acid, sodium carbonate + sodium peroxide, sodium hydroxide + potassium nitrate, and sodium carbonate + potassium nitrate + oxalic acid. The main process involves adding a high-temperature melting reagent, adding the chemical analysis sample and mixing it thoroughly, covering it with a layer of high-temperature melting reagent, melting at high temperature, and then leaching the melt with water or acid to obtain a digestion solution. However, the digestion process using existing high-temperature melting reagents is time-consuming, typically taking 3-4 hours, and has low digestion efficiency, failing to meet the timeliness requirements of chemical analysis results in production and operation processes. Furthermore, splashing and other problems can easily occur during high-temperature melting digestion, limiting the accuracy of the final test results. Summary of the Invention

[0004] The problem addressed by this invention is how to provide a high-temperature melting digestion reagent that can improve the efficiency of high-temperature melting digestion without affecting the accuracy of detection.

[0005] To address the above problems, the present invention provides a high-temperature melting and digestion reagent, comprising a first composition, a second composition, and a third composition, wherein the mass ratio of the first composition, the second composition, and the third composition is (1-5):(20-80):(20-50);

[0006] The first composition comprises an internal standard reagent and a first foaming agent, wherein the mass ratio of the internal standard reagent to the first foaming agent is (1-5):(1-3);

[0007] The second composition comprises a first strong oxidant, a first weak basic oxidant, and a thermally decomposable gas-generating agent, wherein the mass ratio of the first strong oxidant, the first weak basic oxidant, and the thermally decomposable gas-generating agent is (85-95):(7-12):(0.6-1.2).

[0008] The third composition comprises a second weakly basic oxidant, a second strong oxidant, and a second foaming agent, wherein the mass ratio of the second weakly basic oxidant, the second strong oxidant, and the second foaming agent is (27-35):(60-70):(0.5-1.2).

[0009] Wherein, the first foaming agent and the second foaming agent are used to form a two-in-one foaming agent;

[0010] The first composition, the second composition, and the third composition are arranged sequentially from bottom to top in a digestion container, and a chemical sample is placed between the second composition and the third composition.

[0011] Preferably, the internal standard reagent includes one of basic zinc carbonate, copper oxide, and cobalt oxide; the first strong oxidant and the second strong oxidant include one of sodium peroxide, potassium peroxide, and lithium peroxide; the first weakly basic oxidant and the second weakly basic oxidant include one of sodium carbonate and potassium carbonate; and the thermal decomposition gas generator includes one of potassium nitrate, sodium nitrate, and cobalt nitrate.

[0012] The first foaming agent includes one of lithium tetraborate, lithium borate, and borax, and the second foaming agent includes one of sodium fluoride and potassium fluoride.

[0013] Preferably, the mass ratio of the first composition, the second composition, and the third composition is (1-2):(20-50):(10-30);

[0014] In the first composition, the internal standard reagent is basic zinc carbonate, and the first foaming agent is lithium tetraborate;

[0015] In the second composition, the first strong oxidant is sodium peroxide, the first weak alkaline oxidant is sodium carbonate, and the thermal decomposition gas-generating agent is potassium nitrate;

[0016] In the third composition, the second strong oxidant is sodium peroxide, the second weak alkaline oxidant is sodium carbonate, and the second foaming agent is sodium fluoride.

[0017] Preferably, in the first composition, the mass ratio of the first composition, the second composition, and the third composition is 2:20:15;

[0018] In the first composition, the mass ratio of the basic zinc carbonate to the lithium tetraborate is 3:2;

[0019] In the second composition, the mass ratio of sodium peroxide, sodium carbonate, and potassium nitrate is 90:9:1;

[0020] In the third composition, the mass ratio of sodium carbonate, sodium peroxide, and sodium fluoride is 10:40:1.

[0021] The high-temperature melting digestion reagent provided by this invention includes a first composition, a second composition, and a third composition. Through the interaction of different compositions, rapid high-temperature melting digestion is achieved, which can complete the high-temperature melting of chemical samples within 3-5 minutes, significantly improving the efficiency of high-temperature melting. This meets the timeliness requirements for chemical sample testing in production and operation activities, and avoids problems such as contamination and wall adhesion caused by stirring during high-temperature melting digestion, as well as the problem of sample ejection affecting the accuracy of testing. Specifically: The first composition provides an internal standard element and contains one component of the two-in-one foaming agent, which acts as a flux when placed at the bottom; the second composition includes a strong oxidant, a weak alkaline oxidant, and a thermally decomposing gas-generating agent, with a low melting point and strong oxidizing properties, enabling rapid formation of molten liquid and accelerating the melting process. The gas released by the thermally decomposing gas-generating agent during melting also provides an initial stirring effect. Furthermore, the second composition acts as a barrier before forming molten liquid, preventing the reaction between the first and second foaming agents; the third composition covers the chemical sample and provides initial insulation, further accelerating the melting efficiency of the second composition. The third composition also includes a weak alkaline oxidant and a strong oxidant, which can rapidly mix with the first and second compositions during melting, further improving the digestion ability of the chemical sample. The second foaming agent in the third composition reacts with the first foaming agent in the first composition after mixing, generating bubbles and providing a second stirring effect, achieving rapid melting.

[0022] The present invention also provides a high-temperature melting digestion method, based on the high-temperature melting digestion reagent described above, comprising the following steps:

[0023] Step S1: Prepare the first composition, the second composition, and the third composition;

[0024] Step S2: Spread the first composition evenly on the bottom of the digestion container, and then spread the second composition evenly on the surface of the first composition;

[0025] Step S3: Spread the chemical sample evenly on the surface of the second composition, and then cover the surface of the chemical sample with the third composition;

[0026] Step S4: Heat the digestion container to dissolve the first composition, the second composition, the third composition, and the chemical sample to obtain a molten sample;

[0027] Step S5: Cool the molten sample and then mix it with the leachate to obtain the sample leachate;

[0028] Step S6: Adjust the volume of the sample leachate to obtain a digestion solution.

[0029] Preferably, in step S4, the digestion container is heated using a Bunsen lamp for 3 minutes.

[0030] Preferably, in step S5, the digestion container is placed in a water bath for rapid cooling and then removed after 30 seconds.

[0031] Preferably, in step S5, the molten sample is cooled, and then the digestion container is placed in a tall beaker, a dilute hydrochloric acid solution at 95°C is added, and after soaking for 30 seconds, the digestion container is removed to obtain the sample leachate.

[0032] The beneficial effects of the high-temperature melting and digestion method provided by this invention compared to the prior art are the same as those of the high-temperature melting and digestion reagent, and will not be repeated here.

[0033] This invention also provides a method for analyzing chemical samples, comprising the following steps:

[0034] Step T1: Process the chemical sample using the method described above to obtain a digestion solution;

[0035] Step T2: Establish standard working curves for the element to be analyzed using inductively coupled plasma atomic emission spectrometry (ICP-AES).

[0036] Step T3: Run the standard working curve to test the digestion solution and obtain the test results.

[0037] Preferably, step T2 includes:

[0038] Standard solutions with different concentration gradients were prepared using solutions of the element to be analyzed. Sodium chloride and ferric chloride were added to the standard solutions for matrix matching, and hydrochloric acid and internal standard solution were added. Then, the standard solutions were detected using the inductively coupled plasma atomic emission spectrometer to establish the standard working curve.

[0039] This invention combines the above-mentioned high-temperature melting digestion method with the ICP-OES detection method, which enables rapid digestion and analysis of chemical samples, significantly improving the analysis efficiency of chemical samples. Attached Figure Description

[0040] Figure 1 This is a schematic flowchart of the high-temperature melting and digestion method in an embodiment of the present invention;

[0041] Figure 2 This is a schematic flowchart of the chemical sample analysis method in an embodiment of the present invention. Detailed Implementation

[0042] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below.

[0043] It should be noted that, unless otherwise specified, the features in the embodiments of this invention can be combined with each other. The terms "comprising," "including," "containing," and "having" are non-limiting, meaning that other steps and other components that do not affect the results can be added. The above terms cover the terms "composed of" and "substantially composed of." Unless otherwise specified, the materials, equipment, and reagents are commercially available.

[0044] Furthermore, although specific embodiments have been described herein, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways not used in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

[0045] This invention provides a high-temperature melting and digestion reagent, comprising a first composition, a second composition, and a third composition, wherein the mass ratio of the first composition, the second composition, and the third composition is (1-5):(20-80):(20-50);

[0046] The first composition comprises an internal standard reagent and a first foaming agent, wherein the mass ratio of the internal standard reagent to the first foaming agent is (1-5):(1-3);

[0047] The second composition comprises a first strong oxidant, a first weak basic oxidant, and a thermally decomposable gas-generating agent, wherein the mass ratio of the first strong oxidant, the first weak basic oxidant, and the thermally decomposable gas-generating agent is (85-95):(7-12):(0.6-1.2).

[0048] The third composition comprises a second weakly basic oxidant, a second strong oxidant, and a second foaming agent, wherein the mass ratio of the second weakly basic oxidant, the second strong oxidant, and the second foaming agent is (27-35):(60-70):(0.5-1.2).

[0049] Wherein, the first foaming agent and the second foaming agent are used to form a two-in-one foaming agent;

[0050] The first composition, the second composition, and the third composition are arranged sequentially from bottom to top in a digestion container, and a chemical sample is placed between the second composition and the third composition.

[0051] The high-temperature melting digestion reagent provided in this invention includes a first composition, a second composition, and a third composition. Through the interaction of different compositions, rapid high-temperature melting digestion is achieved, which can complete the high-temperature melting of chemical samples within 3-5 minutes, significantly improving the efficiency of high-temperature melting. This meets the timeliness requirements for chemical sample testing in production and operation activities, and avoids problems such as contamination and wall adhesion caused by stirring during high-temperature melting digestion, as well as the problem of sample ejection affecting the accuracy of testing. Specifically: The first composition provides an internal standard element and contains one component of the two-in-one foaming agent, which also has a certain fluxing effect when laid at the bottom; the second composition includes a strong oxidant, a weak alkaline oxidant, and a thermal decomposition gas-generating agent, with a low melting point and strong oxidizing effect, which can quickly form a molten liquid and accelerate the melting process. The gas released by the thermal decomposition gas-generating agent during melting can play a first stirring role. In addition, the second composition has a certain barrier effect before forming a molten liquid, avoiding the reaction between the first and second foaming agents; the third composition covers the chemical sample and has a heat preservation effect in the initial stage, which can further accelerate the melting efficiency of the second composition. The third composition also includes a weak alkaline oxidant and a strong oxidant, which can quickly mix with the first and second compositions during its melting process, further improving the digestion ability of the chemical sample. The second foaming agent in the third composition can react with the first foaming agent in the first composition after mixing, generating bubbles and playing a second stirring role, achieving the purpose of rapid melting.

[0052] In one embodiment, the internal standard reagent includes one of basic zinc carbonate, copper oxide, and cobalt oxide; the first strong oxidant and the second strong oxidant include one of sodium peroxide, potassium peroxide, and lithium peroxide; the first weakly basic oxidant and the second weakly basic oxidant include one of sodium carbonate and potassium carbonate; and the thermal decomposition gas generator includes one of potassium nitrate, sodium nitrate, and cobalt nitrate.

[0053] The first foaming agent includes one of lithium tetraborate, lithium borate, and borax, and the second foaming agent includes one of sodium fluoride and potassium fluoride.

[0054] The internal standard reagent uses a flux-type internal standard element, which effectively eliminates losses during the transfer process caused by the need for melting, decanting, and acidification, reducing operational difficulty and ensuring the accuracy of analytical results. The first and second strong oxidizing agents have low melting points, are low-melting-point basic fluxes, and are strong oxidizing agents; they dissolve rapidly upon heating to form a molten liquid. The first and second weakly basic oxidizing agents can act as fluxes to improve the melting effect of chemical samples. The thermally decomposing gas-generating agent releases a certain amount of gas during heating, producing a stirring effect.

[0055] In addition, the first foaming agent and the second foaming agent can form a two-in-one foaming agent. Initially, the two do not come into contact with each other. As the reagent in the digestion container gradually melts during the heating process, the two come into contact and react to produce gas, which plays a pushing and stirring role.

[0056] Further, the mass ratio of the first composition, the second composition, and the third composition is (1-2):(20-50):(10-30);

[0057] In the first composition, the internal standard reagent is basic zinc carbonate, and the first foaming agent is lithium tetraborate;

[0058] In the second composition, the first strong oxidant is sodium peroxide, the first weak alkaline oxidant is sodium carbonate, and the thermal decomposition gas-generating agent is potassium nitrate;

[0059] In the third composition, the second strong oxidant is sodium peroxide, the second weak alkaline oxidant is sodium carbonate, and the second foaming agent is sodium fluoride.

[0060] Basic zinc carbonate is chemically stable, non-hygroscopic, and of stable quality. It can also provide carbonate ions as a flux during high-temperature melting and decomposition, thereby improving the melting and decomposition effect. Boron in lithium tetraborate is a good flux, and lithium tetraborate and sodium fluoride in the third composition can undergo a chemical reaction in the molten state to generate boron fluoride gas, which can be used for pneumatic stirring of the melt.

[0061] Sodium peroxide is a low-melting-point alkaline flux and a strong oxidizing agent. It can melt at relatively low temperatures to form a molten liquid, thus accelerating the melting process. Sodium carbonate has a good fluxing effect, which also accelerates the melting process. The pyrolysis gas generator is potassium nitrate. When heated, potassium nitrate decomposes and releases a small amount of oxygen, which acts as a pusher for the chemical sample located above the second composition. Since the total amount of potassium nitrate is small, the gas produced will not cause the flux to bubble or bulge, and there will be no splashing. Under the pushing and stirring action, the chemical sample gradually disperses into the melt below for oxidative melting.

[0062] In the third composition, the second strong oxidant is the same as the first strong oxidant, which is sodium peroxide. Sodium peroxide is a low-melting-point alkaline flux and also a strong oxidant. It can melt at a lower temperature to form a molten liquid, thus accelerating the melting process. The second weak alkaline oxidant is the same as the first weak alkaline oxidant, which is sodium carbonate. Sodium carbonate has a good fluxing effect and accelerates the melting process. The second foaming agent is sodium fluoride. When the first and second compositions melt and come into contact with sodium fluoride in the third composition, boron can react with sodium fluoride to produce boron fluoride gas, which has a stirring effect on the melt, so that the chemical sample continues to remain dispersed with the flux base, thereby achieving the effect of rapid melting.

[0063] Furthermore, in the first composition, the mass ratio of the first composition, the second composition, and the third composition is 2:20:15;

[0064] In the first composition, the mass ratio of the basic zinc carbonate to the lithium tetraborate is 3:2;

[0065] In the second composition, the mass ratio of sodium peroxide, sodium carbonate, and potassium nitrate is 90:9:1;

[0066] In the third composition, the mass ratio of sodium carbonate, sodium peroxide, and sodium fluoride is 10:40:1.

[0067] The second composition begins to melt at around 460°C, which can accelerate the high-temperature melting and dissolution process and form a molten liquid within 1 minute. In the first composition, lithium tetraborate is in excess compared to sodium fluoride in the third composition. When the two react, only a small amount of boron fluoride gas is produced, which will not cause the flux to bubble or bulge, and will not cause splashing.

[0068] like Figure 1 As shown, the present invention also provides a high-temperature melting digestion method, based on the high-temperature melting digestion reagent described above, comprising the following steps:

[0069] Step S1: Prepare the first composition, the second composition, and the third composition;

[0070] Step S2: Spread the first composition evenly on the bottom of the digestion container, and then spread the second composition evenly on the surface of the first composition;

[0071] Step S3: Spread the chemical sample evenly on the surface of the second composition, and then cover the surface of the chemical sample with the third composition;

[0072] Step S4: Heat the digestion container to dissolve the first composition, the second composition, the third composition, and the chemical sample to obtain a molten sample;

[0073] Step S5: Cool the molten sample and then mix it with the leachate to obtain the sample leachate;

[0074] Step S6: Adjust the volume of the sample leachate to obtain a digestion solution.

[0075] In step S1, during the preparation of the first composition, the internal standard reagent and the first foaming agent are ground, then mixed evenly according to the ratio, and then sealed and stored; during the preparation of the second composition, the first weakly basic oxidant and the pyrolysis gas-generating agent are ground, then mixed evenly according to the ratio, and then sealed and stored; during the preparation of the third composition, the second strong oxidant, the second weakly basic oxidant and the second foaming agent are mixed evenly according to the ratio, and then sealed and stored.

[0076] In step S2, the digestion container is a crucible, preferably a pure nickel crucible;

[0077] Place the first composition in the crucible and gently rotate the crucible to spread the first composition evenly on the bottom of the crucible. Then place the second composition in the crucible above the first composition and gently rotate the crucible again to spread the second composition evenly on the surface of the first composition.

[0078] In step S3, the chemical sample is placed above the second composition in the crucible, and the crucible is gently shaken to spread the chemical sample evenly over the second composition. Then, the third composition is spread evenly over the chemical sample in the crucible to completely cover the chemical sample.

[0079] The first composition, the second composition, the chemical sample, and the third composition are arranged sequentially from bottom to top in the crucible.

[0080] In step S4, the digestion container is heated using a Bunsen lamp for 3 minutes.

[0081] Bunsen burners are high-temperature heating tools. The temperature of their outer flame can reach 800-900℃, which can rapidly heat the crucible. With the combined action of the first, second, and third compositions, heating for 3 minutes can completely melt and dissolve the chemical sample inside the crucible.

[0082] In step S5, the crucible is placed in a water bath, which allows the molten sample inside the crucible to be rapidly cooled. Then, dilute hydrochloric acid at 90-95℃ is used for leaching, which can complete the sample leaching process within 1-3 minutes, and obtain the sample leachate.

[0083] In step S6, the sample leachate is placed in a volumetric container and the volume is adjusted to obtain the digestion solution, which is then ready for analysis.

[0084] like Figure 2 As shown, this embodiment of the invention also provides a method for analyzing chemical samples, including the following steps:

[0085] Step T1: Process the chemical sample using the method described above to obtain a digestion solution;

[0086] Step T2: Establish standard working curves for the element to be analyzed using inductively coupled plasma atomic emission spectrometry (ICP-AES).

[0087] Step T3: Run the standard working curve to test the digestion solution and obtain the test results.

[0088] Step T2 includes:

[0089] Standard solutions with different concentration gradients were prepared using the solutions of the elements to be analyzed. Sodium chloride and ferric chloride were added to the standard solutions for matrix matching, and hydrochloric acid and internal standard solutions were added. Then, the standard solutions were detected using the inductively coupled plasma optical emission spectrometer (ICP-OES) and the standard working curve was established.

[0090] In other words, based on the element to be analyzed, solutions of the element to be analyzed at known concentrations are prepared into standard solutions with different concentration gradients. When there are multiple elements to be analyzed, solutions of different elements to be analyzed can be mixed to prepare mixed standard solutions (such as a mixture of silicon standard solution, manganese standard solution and phosphorus standard solution). In order to eliminate the interference of chloride ions, sodium ions and iron ions brought about by high-temperature melting and digestion, appropriate amounts of sodium chloride and ferric chloride are added for matrix matching to reduce interference. An internal standard solution (such as zinc standard solution) is added, and ICP-OES is used to detect the standard solutions to establish a simultaneous analytical standard working curve.

[0091] This invention combines the aforementioned high-temperature melting digestion method with ICP-OES detection, enabling rapid digestion and analysis of chemical samples and significantly improving analytical efficiency. High-temperature melting digestion can be completed in 3-5 minutes, sample leaching in 2-3 minutes, and combined with ICP-OES detection technology, the analysis and measurement time for chemical samples can be controlled within 10 minutes.

[0092] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed according to the conditions recommended by the manufacturer.

[0093] Example 1

[0094] Test object: Carbon chromium iron;

[0095] Test items: mass fraction (%) of manganese, silicon, and phosphorus;

[0096] Experimental apparatus: analytical balance, hot plate, Bunsen burner, ICP-PRO spectrometer;

[0097] Experimental reagents:

[0098] Basic lithium carbonate, lithium tetraborate, sodium peroxide, sodium carbonate, potassium nitrate, sodium fluoride, pure iron, hydrochloric acid 1+5, distilled water, zinc standard solution (6g / L);

[0099] Experimental steps:

[0100] 1.1 Grind basic zinc carbonate and lithium tetraborate into a fine powder, and prepare the first composition by accurately weighing and mixing them using an analytical balance at a mass ratio of 3:2. Grind sodium carbonate and potassium nitrate into a fine powder, and prepare the second composition by accurately weighing and mixing them using an analytical balance at a mass ratio of 90:9:1. Prepare the third composition by accurately weighing and mixing them using an analytical balance at a mass ratio of 33:65:1.

[0101] 1.2. Accurately weigh 0.2000g of the first composition using an analytical balance, place it in a pure nickel crucible, and gently rotate the crucible by hand to spread the first composition evenly on the bottom of the crucible; then weigh 2.0g of the second composition, place it in the crucible, and gently rotate the crucible by hand to spread the second composition evenly on top of the first composition;

[0102] 1.3. Accurately weigh 0.2000g of carbon ferrochrome sample using an analytical balance, spread it evenly in the crucible, and gently shake the crucible by hand to spread the sample evenly on top of the second composition; then weigh 1.5g of the third composition and cover it on top of the sample.

[0103] 1.4 Place the crucible over a Bunsen burner flame and heat for 3 minutes. Remove the crucible and place it in a water bath for 30 seconds for rapid cooling. Then place it vertically in a 500 mL stemmed beaker and slowly add 100 mL of dilute hydrochloric acid solution (1+5 hydrochloric acid) at 95 °C. After 30 seconds, remove the crucible from the stemmed beaker and rinse it. Transfer the solution from the stemmed beaker to a 250 mL volumetric flask and dilute to volume with distilled water at 0-5 °C. Shake well to obtain the digestion solution.

[0104] 1.5. Prepare five mixed standard solutions with different concentration gradients by combining silicon, manganese, and phosphorus standard solutions with different concentration gradients. Then, add sodium chloride and ferric chloride solutions with the same concentration as those in the digestion solution to each solution for matrix matching. Add 15 mL of hydrochloric acid and 20 mL of zinc standard solution to each solution. Make up to volume in a volumetric flask to obtain the standard curve solution.

[0105] 1.6. Start the inductively coupled plasma atomic emission spectrometer, preheat for at least 0.5 hours, and detect the standard curve solutions with different concentration gradients to establish a synchronous analysis working curve;

[0106] 1.7. Inductively Coupled Plasma Emission Spectrometry (ICP-ESI) was used to analyze the digestion solution. During the analysis, the recommended spectral lines from technical standards or instrument applications were used. The iron element spectral line was selected, along with the corresponding internal standard line. The mass fractions of silicon, manganese, and phosphorus in the carbon-chromium ferrocarbon sample were calculated. The results are shown in Table 1.

[0107] Table 1. Detection results of silicon, manganese, and phosphorus content in different samples.

[0108] Sample number Sample type Si content (%) Mn content (%) P content (%) A088 Carbon ferrochrome 2.85 0.78 0.025 A089 Carbon ferrochrome 3.79 0.45 0.031 A090 Carbon ferrochrome 3.51 1.29 0.018

[0109] Experimental Example 1

[0110] The same sample from Example 1 was tested using a traditional high-temperature melting digestion method and a chemical spectrophotometric detection method to verify the accuracy of the results obtained by using the high-temperature melting digestion method and detection method provided in this embodiment of the invention.

[0111] Test object: Carbon chromium iron;

[0112] Test items: mass fraction (%) of manganese, silicon, and phosphorus;

[0113] Experimental apparatus: analytical balance, hot plate, alcohol burner, spectrophotometer, volumetric flask;

[0114] Experimental reagents:

[0115] (1) Melting acidification reagents: sodium carbonate, sodium peroxide, pure iron, hydrochloric acid, phosphoric acid, sulfuric acid;

[0116] (2) 1.5% ammonium molybdate, 5% oxalic acid, 1% ascorbic acid, 5% sodium periodate, 5% sodium nitrite, 1% bismuth nitrate, 0.5% silver nitrate;

[0117] Experimental steps:

[0118] 2.1. Accurately weigh sodium carbonate and sodium peroxide using an analytical balance to prepare a composite flux (the mass ratio of sodium carbonate to sodium peroxide is 1:2);

[0119] 2.2 Weigh 5g of composite flux and place it in the crucible. Then, accurately weigh 0.2000g of carbon ferrochrome sample using an analytical balance. Tilt and rotate the crucible continuously to mix the sample and composite flux evenly. Then, weigh 3g of composite reagent to cover the surface.

[0120] 2.3 Place the crucible over an alcohol torch and heat for 5-7 minutes until all the reagents inside the crucible are melted. Then maintain this temperature for 1-2 minutes, remove the crucible, and allow it to cool. Place the crucible in a 300 mL beaker, slowly add 150 mL of water, heat on a hot plate to leach out the solution, and acidify it. Transfer the solution from the beaker to a 250 mL volumetric flask and dilute to volume. Shake well to obtain the digestion solution.

[0121] 2.4 Take 5 portions of manganese standard solution to form manganese standard curve solutions with different concentration gradients. Perform color development according to the sodium periodate oxidation spectrophotometry method, measure the absorbance, and establish the working curve equation. Take 2 appropriate portions of digestion solution, perform color development according to the sodium periodate oxidation spectrophotometry method, and measure the absorbance. Calculate the mass fraction of manganese in the sample.

[0122] 2.5. Take 5 portions of silicon standard solution to form silicon standard curve solutions with different concentration gradients. Develop the color using the silicon molybdenum blue light spectrophotometry method, measure the absorbance, and establish the working curve equation. Take 2 appropriate portions of digestion solution, develop the color using the silicon molybdenum blue light spectrophotometry method, and measure the absorbance. Calculate the mass fraction of silicon in the sample.

[0123] 2.6 Take 5 portions of phosphorus standard solution to form phosphorus standard curve solutions with different concentration gradients. Perform color development according to the phosphorus-bismuth-molybdenum blue spectrophotometric method, measure the absorbance, and establish the working curve equation. Take 2 appropriate portions of digestion solution, perform color development according to the phosphorus-bismuth-molybdenum blue spectrophotometric method, and measure the absorbance. Calculate the mass fraction of phosphorus in the sample.

[0124] The results obtained from this experiment are shown in Table 2:

[0125] Table 2. Detection results of silicon, manganese, and phosphorus content in different samples.

[0126] Sample number Sample type Si content (%) Mn content (%) P content (%) A088 Carbon ferrochrome 2.87 0.77 0.026 A089 Carbon ferrochrome 3.77 0.45 0.031 A090 Carbon ferrochrome 3.49 1.27 0.017

[0127] A comparison of Tables 1 and 2 shows that there is no significant difference between the results obtained in Example 1 and Experimental Example 1, and the results are less than the reproducibility limit specified by the method. This indicates that the high-temperature melting and digestion method and detection method provided by the embodiments of the present invention are basically consistent with the results obtained by the traditional method. However, the embodiments of the present invention significantly simplify the process and improve efficiency.

[0128] Experiment Example 2

[0129] The reaction was verified by changing the proportion of potassium nitrate added to the second composition. Specifically, all other conditions remained the same as in Example 1, but the proportion of potassium nitrate added to the second composition was changed, and the phenomena observed and recorded during the high-temperature melting and digestion process.

[0130] This experiment included six treatments. In treatment 1, the mass ratio of sodium peroxide, sodium carbonate, and potassium nitrate was 90:9:0.5; in treatment 2, it was 90:9:1; in treatment 3, it was 90:9:1.5; in treatment 4, it was 90:9:2.5; in treatment 5, it was 90:9:3.5; and in treatment 6, it was 90:9:5. The results are shown in Table 3.

[0131] Table 3. Records of Phenomena under Different Treatments (Table 1)

[0132]

[0133] It should be noted that the phenomena described in Table 3 occurred before the third composition melted.

[0134] As can be seen from Table 3, treatment 2 (sodium peroxide, sodium carbonate, and potassium nitrate in a mass ratio of 90:9:1) has a good stirring effect, while the other treatments have different problems.

[0135] Experimental Example 3

[0136] The reaction was verified by changing the proportion of sodium fluoride added to the third composition. Specifically, all other conditions remained the same as in Example 1, but the proportion of sodium fluoride added to the second composition was changed, and the phenomena observed and recorded during the high-temperature melting and digestion process.

[0137] This experiment included six treatments. In treatment 1, the mass ratio of sodium carbonate, sodium peroxide, and sodium fluoride was 33:65:0.5; in treatment 2, the ratio was 33:65:1; in treatment 3, the ratio was 33:65:1.5; in treatment 4, the ratio was 33:65:2.5; in treatment 5, the mass ratio of sodium peroxide, sodium carbonate, and potassium nitrate was 33:65:3.5; and in treatment 6, the mass ratio was 33:65:5. The results are shown in Table 4.

[0138] Table 4. Records of Phenomena under Different Treatments (Table 2)

[0139]

[0140] It should be noted that the phenomena described in Table 4 occur when the third composition melts.

[0141] As can be seen from Table 4, treatment 1 (mass ratio of sodium carbonate, sodium peroxide, and sodium fluoride is 33:65:0.5) and treatment 2 (mass ratio of sodium carbonate, sodium peroxide, and sodium fluoride is 33:65:1) have a stirring effect, while the other treatments have different problems.

[0142] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A high-temperature melting digestion reagent, characterized in that, It includes a first composition, a second composition, and a third composition, wherein the mass ratio of the first composition, the second composition, and the third composition is (1-5):(20-80):(20-50); The first composition comprises an internal standard reagent and a first foaming agent, wherein the mass ratio of the internal standard reagent to the first foaming agent is (1-5):(1-3); The second composition comprises a first strong oxidant, a first weak basic oxidant, and a thermally decomposable gas-generating agent, wherein the mass ratio of the first strong oxidant, the first weak basic oxidant, and the thermally decomposable gas-generating agent is (85-95):(7-12):(0.6-1.2). The third composition comprises a second weakly basic oxidant, a second strong oxidant, and a second foaming agent, wherein the mass ratio of the second weakly basic oxidant, the second strong oxidant, and the second foaming agent is (27-35):(60-70):(0.5-1.2). Wherein, the first foaming agent and the second foaming agent are used to form a two-in-one foaming agent; The first composition, the second composition, and the third composition are arranged sequentially from bottom to top in a digestion container, and a chemical sample is placed between the second composition and the third composition.

2. The high-temperature melting and digestion reagent according to claim 1, characterized in that, The internal standard reagent includes one of basic zinc carbonate, copper oxide, and cobalt oxide; the first strong oxidant and the second strong oxidant include one of sodium peroxide, potassium peroxide, and lithium peroxide; the first weak alkaline oxidant and the second weak alkaline oxidant include one of sodium carbonate and potassium carbonate; and the thermal decomposition gas generator includes one of potassium nitrate, sodium nitrate, and cobalt nitrate. The first foaming agent includes one of lithium tetraborate, lithium borate, and borax, and the second foaming agent includes one of sodium fluoride and potassium fluoride.

3. The high-temperature melting and digestion reagent according to claim 2, characterized in that, The mass ratio of the first composition, the second composition, and the third composition is (1-2):(20-50):(10-30); In the first composition, the internal standard reagent is basic zinc carbonate, and the first foaming agent is lithium tetraborate; In the second composition, the first strong oxidant is sodium peroxide, the first weak alkaline oxidant is sodium carbonate, and the thermal decomposition gas-generating agent is potassium nitrate; In the third composition, the second strong oxidant is sodium peroxide, the second weak alkaline oxidant is sodium carbonate, and the second foaming agent is sodium fluoride.

4. The high-temperature melting and digestion reagent according to claim 3, characterized in that, In the first composition, the mass ratio of the first composition, the second composition, and the third composition is 2:20:15; In the first composition, the mass ratio of the basic zinc carbonate to the lithium tetraborate is 3:2; In the second composition, the mass ratio of sodium peroxide, sodium carbonate, and potassium nitrate is 90:9:1; In the third composition, the mass ratio of sodium carbonate, sodium peroxide, and sodium fluoride is 33:65:

1.

5. A high-temperature melting digestion method, based on the high-temperature melting digestion reagent as described in any one of claims 1-4, characterized in that, Includes the following steps: Step S1: Prepare the first composition, the second composition, and the third composition; Step S2: Spread the first composition evenly on the bottom of the digestion container, and then spread the second composition evenly on the surface of the first composition; Step S3: Spread the chemical sample evenly on the surface of the second composition, and then cover the surface of the chemical sample with the third composition; Step S4: Heat the digestion container to dissolve the first composition, the second composition, the third composition, and the chemical sample to obtain a molten sample; Step S5: Cool the molten sample and then mix it with the leachate to obtain the sample leachate; Step S6: Adjust the volume of the sample leachate to obtain a digestion solution.

6. The high-temperature melting and digestion method according to claim 5, characterized in that, In step S4, the digestion container is heated using a Bunsen lamp for 3 minutes.

7. The high-temperature melting and digestion method according to claim 5, characterized in that, In step S5, the digestion container is placed in a water bath for rapid cooling, and then removed after 30 seconds.

8. The high-temperature melting and digestion method according to claim 5, characterized in that, In step S5, the molten sample is cooled, and then the digestion container is placed in a tall beaker. A dilute hydrochloric acid solution at 95°C is added, and after soaking for 30 seconds, the digestion container is removed to obtain the sample leachate.

9. A method for analyzing chemical samples, characterized in that, Includes the following steps: Step T1: The chemical sample is treated using the method described in any one of claims 5-8 to obtain a digestion solution; Step T2: Establish standard working curves for the element to be analyzed using inductively coupled plasma atomic emission spectrometry (ICP-AES). Step T3: Run the standard working curve to test the digestion solution and obtain the test results.

10. The chemical sample analysis method according to claim 9, characterized in that, Step T2 includes: Standard solutions with different concentration gradients were prepared using solutions of the element to be analyzed. Sodium chloride and ferric chloride were added to the standard solutions for matrix matching, and hydrochloric acid and internal standard solution were added. Then, the standard solutions were detected using the inductively coupled plasma atomic emission spectrometer to establish the standard working curve.

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