Method for detecting content of elemental aluminum in aluminum slag

Abstract

The invention discloses a method for detecting the content of elemental aluminum in aluminum slag, which comprises the following steps: fully crushing and sieving an aluminum slag sample to be detected, and sampling by a quartering method to obtain crushed aluminum slag; the crushed aluminum slag is dried and naturally cooled to the room temperature, and a sample is obtained; then carrying out heating treatment on the sample and the dried sulfur powder; adding a dry organic solvent, and fully stirring to obtain a stirred solution; filtering to obtain filtrate; and concentrating to be dry, and calculating the content of elemental aluminum in the to-be-detected aluminum slag sample. According to the invention, fewer types and dosages of reagents are selected, so that the possibility of introducing errors is further reduced; after the reagent is used, secondary circulation can be realized, so that the waste of the reagent is reduced; the aluminum simple substance content is obtained by a gravimetric method, high selectivity is achieved, and it is ensured that the measurement result is not interfered; the aluminum content is calculated in a weighing mode, the process has low requirements for basic skills of operators, and the method is convenient for the operators in the field to use.

Description

Technical Field

[0001] The invention relates to the technical field of chemical analysis, and in particular to a method for detecting the content of elemental aluminum in aluminum slag. Background Art

[0002] Aluminum slag, also known as "aluminum ash", is an industrial solid waste generated during the electrolytic aluminum oxide, metal aluminum processing, and waste aluminum recycling process. It can be divided into primary aluminum ash and secondary aluminum ash according to the aluminum content in the aluminum ash:

[0003] 1) Primary aluminum ash is also called white ash, the main components of which are aluminum and aluminum oxide, of which the metallic aluminum content can reach 30% to 70%;

[0004] 2) Secondary aluminum ash, also known as black ash, comes from the residues produced by recycling primary aluminum ash or aluminum alloy refining. The metallic aluminum content in secondary aluminum ash is only 12% to 18%, and the main components are aluminum oxide, salt flux, oxides, etc. Secondary aluminum ash is difficult to handle due to its low aluminum content and high impurities. Factories generally directly landfill it. However, with the increase in aluminum ash production, if it is directly dumped as waste slag, it will not only waste aluminum resources but also cause environmental problems.

[0005] With the development of science and technology, the industrial application of aluminum in aluminum slag is becoming more and more extensive. The content of aluminum in aluminum slag determines its different industrial uses, and it is very important to accurately detect the content of aluminum in aluminum slag. At present, the methods for detecting the content of aluminum in aluminum slag mainly use gas volumetric method and EDTA titration method. When the gas volumetric method is used, the hydrogen generated by the reaction of aluminum and water under acidic conditions is used as the indicator for determining the content of aluminum. Therefore, the air tightness of the equipment and the stability of atmospheric pressure are extremely high, and it is difficult to accurately and quickly detect the content of aluminum in aluminum particles; and the impurity AlN will react with water under acidic conditions to generate NH3, affecting the accuracy of the test results. When the EDTA titration method is used, the operation steps are cumbersome and the efficiency is low; and other components that may exist in aluminum slag, such as Fe, Ca, Mg, Zn and other impurities, will consume EDTA, which has a great interference with the detection of aluminum content. These methods have cumbersome operation steps, require specific instruments and equipment during the detection process, and have poor stability. They are not suitable for accurate and rapid detection of aluminum content in aluminum slag.

[0006] Therefore, it is necessary to develop a detection method for the elemental aluminum content in aluminum slag that is simple to operate, easy to implement and stable, which is of great significance to the development and progress of the aluminum industry and the construction of ecological civilization. Summary of the invention

[0007] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for detecting the content of elemental aluminum in aluminum slag, which is not only simple to operate, but also requires low-priced equipment and good stability.

[0008] The present invention determines the content of elemental aluminum in aluminum slag by weight method, and is applicable to the content of elemental aluminum in samples such as electrolytic aluminum slag, and the present invention is only applicable to the dry basis state of the above samples.

[0009] To achieve the above purpose, the technical solution designed by the present invention is as follows:

[0010] The present invention provides a method for detecting the content of elemental aluminum in aluminum slag, comprising the following steps:

[0011] Step S1: fully crush and sieve the aluminum slag sample to be tested, and obtain crushed aluminum slag by quartering method;

[0012] Step S2: drying the crushed aluminum slag and naturally cooling it to room temperature under anhydrous and oxygen-free conditions to obtain a test material;

[0013] Step S3: weighing m of the sample and m1 of the dry sulfur powder, and then heating them in an anhydrous and oxygen-free operating environment;

[0014] Step S4: naturally cooling to room temperature under anhydrous and oxygen-free conditions, adding a dry organic solvent, and stirring sufficiently to obtain a stirring liquid;

[0015] Step S5: filtering the stirred liquid under anhydrous and oxygen-free conditions to obtain a filtrate;

[0016] Step S6: Concentrate the filtrate to dryness to obtain a solid with a mass of m2; then use the following formula to calculate the elemental aluminum content ω in the aluminum slag sample to be tested:

[0017]

[0018] Where: ω is the content of elemental aluminum in aluminum slag, %;

[0019] m is the mass of the sample, g;

[0020] m1 is the amount of sulfur powder added, g;

[0021] m2 is the amount of sulfur powder recovered, g;

[0022] k is the mass conversion coefficient of aluminum and sulfur, k = 0.56096.

[0023] Furthermore, in the step S1, the mesh size of the sieving is 30-100 meshes.

[0024] Furthermore, in step S2, the drying temperature is 105±5°C and the drying time is 60-120min.

[0025] Furthermore, in step S3, the mass ratio of the sample m to the sulfur powder m1 is 1:2-3.

[0026] Furthermore, in step S3, the heating temperature is 200-400° C., and the heating time is 15-30 min.

[0027] Furthermore, the heating temperature is 350°C.

[0028] Furthermore, in step S4, the organic solvent is one or more of carbon disulfide, benzene, and carbon tetrachloride; wherein the mass ratio of sulfur powder to the organic solvent is 1:5-10.

[0029] Furthermore, the organic solvent is carbon disulfide.

[0030] The organic solvent may also be other non-polar solvents that can dissolve sulfur powder and other components in the aluminum slag are insoluble in the organic solvent.

[0031] Furthermore, in step S4, the stirring time is 10-30 minutes.

[0032] Furthermore, the anhydrous and oxygen-free condition is an inert gas environment with an oxygen content of less than 1 ppm and a moisture content of less than 1 ppm.

[0033] Beneficial effects of the present invention:

[0034] (1) The present invention uses fewer reagents and uses fewer amounts, further reducing the possibility of introducing errors;

[0035] (2) The reagent of the present invention can be recycled twice after use, thus reducing the waste of reagent;

[0036] (3) The present invention uses a weight method to obtain the aluminum content, which is highly selective and ensures that the measurement results are not interfered with;

[0037] (4) The present invention calculates the aluminum content by weighing, and the process requires relatively low basic skills of the operator, which is convenient for use by people in this field.

[0038] In summary, the detection method of the present invention has no limitation on the content of metallic aluminum and can detect metallic aluminum in any content range in aluminum slag, and has a wide range of applications. DETAILED DESCRIPTION

[0039] The present invention is further described in detail below in conjunction with specific embodiments so that those skilled in the art can understand.

[0040] Example 1

[0041] A method for detecting the content of elemental aluminum in aluminum slag comprises the following steps:

[0042] Step S1: The aluminum slag sample to be tested is fully crushed and sieved through 40 meshes, and the crushed aluminum slag is obtained by sampling using the quartering method;

[0043] Step S2: placing the crushed aluminum slag in an oven at a temperature of 105±5° C. and drying it for 60 min, and naturally cooling it to room temperature in a vacuum glove box (the anhydrous and oxygen-free condition of the vacuum glove box is an inert gas environment with an oxygen content of less than 1 ppm and a moisture content of less than 1 ppm) to obtain a test material;

[0044] Step S3: weighing m=1.0049 g of the sample and m1=2.5321 g of dried sulfur powder into a 100 ml round-bottom flask, and then heating them at 200° C. for 30 min in a vacuum glove box;

[0045] Step S4: then naturally cool to room temperature in a vacuum glove box, add 12.7755 g of dry carbon disulfide, and stir thoroughly for 30 minutes to obtain a stirring liquid;

[0046] Step S5: filtering the stirred liquid in a vacuum glove box to obtain a filtrate;

[0047] Step S6: Concentrate the filtrate to dryness to obtain m2 = 2.0819 g of solid; then use the following formula to calculate the elemental aluminum content ω in the aluminum slag sample to be tested:

[0048]

[0049] Where: ω is the content of elemental aluminum in aluminum slag, %;

[0050] m is the mass of the sample, g;

[0051] m1 is the amount of sulfur powder added, g;

[0052] m2 is the amount of sulfur powder recovered, g;

[0053] k is the mass conversion coefficient of aluminum and sulfur, k = 0.56096.

[0054] Example 2

[0055] A method for detecting the content of elemental aluminum in aluminum slag comprises the following steps:

[0056] Step S1: The aluminum slag sample to be tested is fully crushed and sieved through 40 meshes, and the crushed aluminum slag is obtained by sampling using the quartering method;

[0057] Step S2: placing the crushed aluminum slag in an oven at a temperature of 105±5° C. and drying it for 60 min, and naturally cooling it to room temperature in a vacuum glove box (the anhydrous and oxygen-free condition of the vacuum glove box is an inert gas environment with an oxygen content of less than 1 ppm and a moisture content of less than 1 ppm) to obtain a test material;

[0058] Step S3: weighing m=2.0133 g of the sample and m1=5.0261 g of dried sulfur powder into a 100 ml round-bottom flask, and then heating them at 280° C. for 30 min in a vacuum glove box;

[0059] Step S4: then naturally cool to room temperature in a vacuum glove box, add 25.3475 g of dry carbon disulfide, and stir thoroughly for 30 minutes to obtain a stirring liquid;

[0060] Step S5: filtering the stirred liquid in a vacuum glove box to obtain a filtrate;

[0061] Step S6: Concentrate the filtrate to dryness to obtain m2 = 4.1235 g of solid; then use the following formula to calculate the elemental aluminum content ω in the aluminum slag sample to be tested:

[0062]

[0063] Where: ω is the content of elemental aluminum in aluminum slag, %;

[0064] m is the mass of the sample, g;

[0065] m1 is the amount of sulfur powder added, g;

[0066] m2 is the amount of sulfur powder recovered, g;

[0067] k is the mass conversion coefficient of aluminum and sulfur, k = 0.56096.

[0068] Example 3

[0069] A method for detecting the content of elemental aluminum in aluminum slag comprises the following steps:

[0070] Step S1: The aluminum slag sample to be tested is fully crushed and sieved through 40 meshes, and the crushed aluminum slag is obtained by sampling using the quartering method;

[0071] Step S2: placing the crushed aluminum slag in an oven at a temperature of 105±5°C for 100 min, and naturally cooling it to room temperature in a vacuum glove box (the anhydrous and oxygen-free condition of the vacuum glove box is an inert gas environment with an oxygen content of less than 1 ppm and a moisture content of less than 1 ppm) to obtain a test material;

[0072] Step S3: weighing m=2.0125 g of the sample and m1=6.0041 g of dried sulfur powder into a 100 ml round-bottom flask, and then heating them at 350° C. for 30 min in a vacuum glove box;

[0073] Step S4: then naturally cool to room temperature in a vacuum glove box, add 59.8991 g of dry carbon disulfide, and stir thoroughly for 20 minutes to obtain a stirring liquid;

[0074] Step S5: filtering the stirred liquid in a vacuum glove box to obtain a filtrate;

[0075] Step S6: Concentrate the filtrate to dryness to obtain m2 = 5.0986 g of solid; then use the following formula to calculate the elemental aluminum content ω in the aluminum slag sample to be tested:

[0076]

[0077] Where: ω is the content of elemental aluminum in aluminum slag, %;

[0078] m is the mass of the sample, g;

[0079] m1 is the amount of sulfur powder added, g;

[0080] m2 is the amount of sulfur powder recovered, g;

[0081] k is the mass conversion coefficient of aluminum and sulfur, k = 0.56096.

[0082] Example 4

[0083] A method for detecting the content of elemental aluminum in aluminum slag comprises the following steps:

[0084] Step S1: The aluminum slag sample to be tested is fully crushed and sieved through 40 meshes, and the crushed aluminum slag is obtained by sampling using the quartering method;

[0085] Step S2: placing the crushed aluminum slag in an oven at a temperature of 105±5°C for 100 min, and naturally cooling it to room temperature in a vacuum glove box (the anhydrous and oxygen-free condition of the vacuum glove box is an inert gas environment with an oxygen content of less than 1 ppm and a moisture content of less than 1 ppm) to obtain a test material;

[0086] Step S3: weighing m=2.0119 g of the sample and m1=6.0038 g of dried sulfur powder into a 100 ml round-bottom flask, and then heating them at 400° C. for 30 min in a vacuum glove box;

[0087] Step S4: then naturally cool to room temperature in a vacuum glove box, add 59.8665 g of dry carbon disulfide, and stir thoroughly for 20 minutes to obtain a stirring liquid;

[0088] Step S5: filtering the stirred liquid in a vacuum glove box to obtain a filtrate;

[0089] Step S6: Concentrate the filtrate to dryness to obtain m2 = 5.0910 g of solid; then use the following formula to calculate the elemental aluminum content ω in the aluminum slag sample to be tested:

[0090]

[0091] Where: ω is the content of elemental aluminum in aluminum slag, %;

[0092] m is the mass of the sample, g;

[0093] m1 is the amount of sulfur powder added, g;

[0094] m2 is the amount of sulfur powder recovered, g;

[0095] k is the mass conversion coefficient of aluminum and sulfur, k = 0.56096.

[0096] Comparative Example 1

[0097] The method for detecting aluminum content comprises the following steps:

[0098] Step S1: The aluminum slag sample to be tested is fully crushed and sieved through a 40-mesh sieve, and crushed aluminum slag is obtained by quartering;

[0099] Step S2: placing the crushed aluminum slag in an oven at a temperature of 105±5°C and fully drying it for 60 minutes;

[0100] Step S3: placing the fully dried aluminum slag in a vacuum glove box and naturally cooling it to room temperature to obtain a sample;

[0101] Step S4: weigh m = 2.0110 g of the sample and m1 = 5.0306 g of fully dried sulfur powder into a 100 ml round-bottom flask, and heat them at 180° C. for 30 min in a vacuum glove box;

[0102] Step S5: The reaction container is naturally cooled to room temperature in a vacuum glove box, 25.3650 g of dry carbon disulfide is added, and stirred for 30 minutes to obtain a stirring liquid;

[0103] Step S6: filtering the stirred liquid in a vacuum glove box to obtain a filtrate;

[0104] Step S7: Concentrate the filtrate to dryness to obtain m2 = 4.1569 g of solid; then use the following formula to calculate the elemental aluminum content ω in the aluminum slag sample to be tested:

[0105]

[0106] Where: ω is the content of elemental aluminum in aluminum slag, %;

[0107] m is the mass of the sample, g;

[0108] m1 is the amount of sulfur powder added, g;

[0109] m2 is the amount of sulfur powder recovered, g;

[0110] k is the mass conversion coefficient of aluminum and sulfur, k = 0.56096.

[0111] Comparative Example 2

[0112] The method for detecting aluminum content comprises the following steps:

[0113] Step S1: The aluminum slag sample to be tested is fully crushed and sieved through 40 meshes, and the crushed aluminum slag is obtained by quartering;

[0114] Step S2: placing the crushed aluminum slag in an oven at a temperature of 105±5°C and fully drying it for 60 minutes;

[0115] Step S3: placing the fully dried aluminum slag in a vacuum glove box and naturally cooling it to room temperature to obtain a sample;

[0116] Step S4: weigh m = 2.0129 g of the sample and m1 = 5.0314 g of fully dried sulfur powder into a 100 ml round-bottom flask, and heat them at 450° C. for 30 min in a vacuum glove box;

[0117] Step S5: The reaction container is naturally cooled to room temperature in a vacuum glove box, 25.3611 g of dry carbon disulfide is added, and stirred for 30 minutes to obtain a stirring liquid;

[0118] Step S6: filtering the stirred liquid in a vacuum glove box to obtain a filtrate;

[0119] Step S7: Concentrate the filtrate to dryness to obtain m2-=4.0665 g of solid; then use the following formula to calculate the elemental aluminum content ω in the aluminum slag sample to be tested:

[0120]

[0121] Where: ω is the elemental aluminum content in the aluminum slag sample to be tested, %;

[0122] m is the mass of the sample, g;

[0123] m1 is the amount of sulfur powder added, g;

[0124] m2 is the amount of sulfur powder recovered, g;

[0125] k is the mass conversion coefficient of aluminum and sulfur, k = 0.56096.

[0126] The comparison of the elemental aluminum content in the aluminum slag detected in the above Examples 1 to 3 and Comparative Examples 1 to 2 is shown in Table 1 below:

[0127] Table 1 Test values ​​and error values ​​of metal aluminum content detected in the embodiments and comparative examples

[0128] Case Metal aluminum content test value Industry standard test value Error value Example 1 25.13％ 25.29％ 0.17％ Example 2 25.15％ 25.29％ 0.14％ Example 3 25.24％ 25.29％ 0.05％ Example 4 25.45％ 25.29％ 0.16％ Comparative Example 1 24.37％ 25.29％ 0.92％ Comparative Example 2 26.89％ 25.29％ 1.60％

[0129] Note: Theoretical value: The existing aluminum slag samples were measured using the metal aluminum content determination method in the industry standard YS / T 1179.2-2017. The average result of three repeated measurements was 25.29%, which was used to verify the accuracy of the test results. The detection range of the metal aluminum content in the industry standard is 5.00% to 35.00%.

[0130] As shown in Table 1: In the detection method of Comparative Example 1, when the reaction temperature is lower than 200°C, the sulfur powder cannot fully react with the aluminum element, and after adding carbon disulfide, the remaining sulfur powder content is high, resulting in a low detection result; in the detection method of Comparative Example 2, when the reaction temperature is higher than 400°C, part of the sulfur powder will volatilize due to heat during the reaction process, and the remaining sulfur powder content is low, resulting in a high detection result. In the detection method of the present invention, the reaction temperature is 200-400°C, so that the sulfur powder and the aluminum element fully react, and the detection error is small, among which the best effect is achieved when the reaction temperature is 350°C.

[0131] Although the above embodiments have been described in detail, they are only a part of the embodiments of the present invention, not all of them. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all belong to the protection scope of the present invention.

Claims

1. A method for detecting the content of elemental aluminum in aluminum slag, characterized in that: The following steps are involved: Step S1: fully crush and sieve the aluminum slag sample to be tested, and obtain crushed aluminum slag by quartering method; Step S2: drying the crushed aluminum slag and naturally cooling it to room temperature under anhydrous and oxygen-free conditions to obtain a test material; Step S3: weighing m of the sample and m1 of the dry sulfur powder, and then heating them in an anhydrous and oxygen-free operating environment; Step S4: naturally cooling to room temperature under anhydrous and oxygen-free conditions, adding a dry organic solvent, and stirring sufficiently to obtain a stirring liquid; Step S5: filtering the stirred liquid under anhydrous and oxygen-free conditions to obtain a filtrate; Step S6: Concentrate the filtrate to dryness to obtain a solid with a mass of m2; then use the following formula to calculate the elemental aluminum content ω in the aluminum slag sample to be tested: Where: ω is the content of elemental aluminum in aluminum slag, %; m is the mass of the sample, g; m1 is the amount of sulfur powder added, g; m2 is the amount of sulfur powder recovered, g; k is the mass conversion coefficient of aluminum and sulfur, k = 0.56096.

2. The detection method according to claim 1, characterized in that: In the step S1, the mesh size of the sieving is 30-100 meshes.

3. The detection method according to claim 1, characterized in that: In step S2, the drying temperature is 105±5° C. and the drying time is 60-120 min.

4. The detection method according to claim 1, characterized in that: In the step S3, the mass ratio of the sample m to the sulfur powder m1 is 1:2-3.

5. The detection method according to claim 1, characterized in that: In step S3, the heating temperature is 200-400° C. and the heating time is 15-30 minutes.

6. The detection method according to claim 1 or 5, characterized in that: The heating temperature is 350°C.

7. The detection method according to claim 1, characterized in that: In step S4, the organic solvent is one or more of carbon disulfide, benzene, and carbon tetrachloride; wherein the mass ratio of sulfur powder to the organic solvent is 1:5-10.

8. The detection method according to claim 1 or 7, characterized in that: The organic solvent is carbon disulfide.

9. The detection method according to claim 1 or 7, characterized in that: In step S4, the stirring time is 10-30 min.

10. The detection method according to claim 1, characterized in that: The anhydrous and oxygen-free condition is an inert gas environment with an oxygen content of less than 1 ppm and a moisture content of less than 1 ppm.

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