Method for detecting silver content in pure silver

Abstract

The invention discloses a method for detecting the content of silver in pure silver, and belongs to the field of chemical material detection, the pure silver is dissolved by dilute nitric acid, hydrochloric acid is added to form silver chloride precipitate, the precipitate is filtered and put into a crucible, sodium carbonate and sodium tetraborate decahydrate are added, salt in the crucible is dissolved by hot water after high-temperature melting, and the pure silver is obtained. And weighing to calculate the silver content in the pure silver. According to the method, silver chloride is reduced into silver through molten sodium carbonate, the silver content in pure silver is measured through a classic gravimetric method, and the method is low in cost, simple and accurate. A simple and accurate product control method can be provided for the production field, and a good detection means is provided for the field of analysis and detection.

Description

Technical Field

[0001] The present invention relates to the field of chemical material detection, and in particular to a method for detecting the silver content in pure silver. Background Art

[0002] Silver is a precious metal chemical material widely used in electronics, electroplating, photosensitive materials, chemical engineering, and scientific research. The silver content of pure silver products is a key quality indicator, and its determination has traditionally been done using titration or impurity reduction methods. For example, Chinese Patent No. CN202411669632.7 discloses an analytical test method for determining the content of impurity elements in high-purity silver using inductively coupled plasma mass spectrometry, a technique that falls within the technical field of silver chemical analysis. In a strongly oxidizing nitric acid solution, silver and some impurities are converted into soluble ions. In a nitric acid-hydrochloric acid system, impurities such as Au, Pt, and Rh are converted into soluble ions. Thiourea complexation of the silver ions fully ionizes the silver and impurity elements, forming a soluble solution that is then analyzed by ICP-MS. Analytical elements include Cu, Bi, Fe, Pb, Se, Te, As, Mg, Co, Mn, Ni, Zn, Cd, Ca, Al, Sb, Pd, Sn, Rh, Au, and Pt. The present invention mainly solves the problems of dissolving impurities in high-purity silver and determining the impurity content, and can be used as a conventional method for analyzing and testing the impurity content in high-purity silver.

[0003] However, existing technologies for higher-purity silver use a titration method that falls short, while impurity reduction methods cannot directly measure silver content. Titration suffers from inaccuracy issues for silver products exceeding 99% purity. Impurity reduction methods generally only measure elements required by standards and cannot exclude non-standard elements that may be present in pure silver, thus failing to meet the quality requirements of pure silver products. Therefore, there is an urgent need for an accurate method for measuring the silver content in pure silver. Summary of the Invention

[0004] Based on this, in order to solve one of the above problems, the present invention provides a method for checking the silver content in pure silver, and the specific technical solution is as follows:

[0005] A method for detecting the silver content in pure silver, the detection method comprising the following steps:

[0006] Weigh the pure silver sample to the nearest 0.0001g and record it as m1;

[0007] Place the weighed pure silver sample in a beaker, add water and nitric acid, heat until the silver is completely dissolved, then add an appropriate amount of chloride, cover and boil until the silver chloride is completely precipitated, filter after the solution cools, and wrap the silver chloride precipitate for later use;

[0008] The wrapped silver chloride precipitate is placed in a crucible paved with reagents and covered with sodium carbonate and sodium tetraborate decahydrate; the crucible is then covered and placed in a muffle furnace, heated, and cooled naturally;

[0009] After cooling, remove the crucible and place it in a 200mL beaker. Add water to cover the crucible and boil until the salts are completely dissolved. Then filter the liquid and place the silver particles on the filter paper back into a clean beaker for cleaning. Then place the cleaned silver particles into the beaker and heat and dry them on a hot plate to obtain the weight of the silver, which is recorded as m2.

[0010] According to the calculation formula, the silver content in pure silver is calculated.

[0011] Furthermore, the calculation formula is as follows:

[0012]

[0013] Furthermore, the chloride is at least one of hydrochloric acid, sodium chloride and potassium chloride.

[0014] Furthermore, the silver chloride precipitate is wrapped with a carbon-containing material, and the carbon-containing material is at least one of filter paper, plastic film, non-woven fabric and graphite paper.

[0015] Furthermore, the reagent is at least one of sodium carbonate, potassium carbonate and borax.

[0016] Furthermore, the temperature rising treatment is: uniformly rising the temperature from room temperature to 455° C. to 1100° C., and keeping the temperature for 10 to 60 minutes.

[0017] Furthermore, the cleaning treatment uses an acetic acid aqueous solution.

[0018] Furthermore, the weight of silver can be obtained by weighing directly after drying, or by adding 15 mL of hydrochloric acid to the filtrate, adjusting the volume to a 100 mL volumetric flask, and measuring the silver content using an air-acetylene flame at a wavelength of 328.1 nm using an atomic absorption spectrometer; or by using an inductively coupled plasma atomic emission spectrometer (ICP) to measure the silver content.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The present invention involves dissolving a pure silver sample in nitric acid, converting it into a silver chloride precipitate, adding sodium carbonate and sodium tetraborate decahydrate, and then melting the solution at high temperature. The salts in the crucible are then dissolved in hot water to obtain pure silver. The silver content of the pure silver can be calculated by weighing the sample. This method utilizes molten sodium carbonate to reduce the silver chloride to silver, and the silver content of the pure silver is determined using a classic gravimetric method. This method is low-cost, simple, and accurate.

[0021] 2. The present invention can effectively separate other impurity elements, and then convert silver chloride into pure silver by utilizing the property that silver chloride can be reduced to pure silver by molten sodium carbonate. The silver content in the pure silver is obtained by the classic gravimetric method, which can provide a simple and accurate product control method for the production field and a good detection means for the analysis and detection field. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with its embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not limit the scope of protection of the present invention.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0024] In one embodiment of the present invention, a method for detecting the silver content in pure silver comprises the following steps:

[0025] Weigh the pure silver sample to the nearest 0.0001g and record it as m1;

[0026] Place the weighed pure silver sample in a beaker, add water and nitric acid, heat until the silver is completely dissolved, then add an appropriate amount of chloride, cover and boil until the silver chloride is completely precipitated, filter after the solution cools, and wrap the silver chloride precipitate for later use;

[0027] The wrapped silver chloride precipitate is placed in a crucible paved with reagents and covered with sodium carbonate and sodium tetraborate decahydrate; the crucible is then covered and placed in a muffle furnace, heated, and cooled naturally;

[0028] After cooling, remove the crucible and place it in a 200mL beaker. Add water to cover the crucible and boil until the salts are completely dissolved. Then filter the liquid and place the silver particles on the filter paper back into a clean beaker for cleaning. Then place the cleaned silver particles into the beaker and heat and dry them on a hot plate to obtain the weight of the silver, which is recorded as m2.

[0029] According to the calculation formula, the silver content in pure silver is calculated.

[0030] In one embodiment, the calculation formula is as follows:

[0031]

[0032] In one embodiment, the chloride is at least one of hydrochloric acid, sodium chloride and potassium chloride.

[0033] In one embodiment, the silver chloride precipitate is wrapped with a carbon-containing material, and the carbon-containing material is at least one of filter paper, plastic film, non-woven fabric and graphite paper.

[0034] In one embodiment, the reagent is at least one of sodium carbonate, potassium carbonate and borax.

[0035] In one embodiment, the temperature rising treatment is: uniformly rising the temperature from room temperature to 455°C to 1100°C, and keeping the temperature for 10 to 60 minutes.

[0036] In one embodiment, the cleaning process uses an acetic acid aqueous solution.

[0037] In one embodiment, the method for obtaining the weight of silver is to weigh directly after drying, or to add 15 mL of hydrochloric acid to the filtrate, dilute to a 100 mL volumetric flask, and measure the silver content at a wavelength of 328.1 nm using an air-acetylene flame on an atomic absorption spectrometer; or to measure the silver content using an inductively coupled plasma atomic emission spectrometer (ICP).

[0038] The above scheme can obtain the silver content in pure silver with high accuracy through simple reagents.

[0039] The embodiments of the present invention will be described in detail below with reference to specific examples.

[0040] Example 1:

[0041] A method for detecting the silver content in pure silver comprises the following steps:

[0042] Weigh 0.50g of pure silver, record it as m1; put the weighed pure silver into a beaker, add water and nitric acid, heat until the silver is completely dissolved, then add an appropriate amount of hydrochloric acid to the beaker, cover and boil until the silver chloride is completely precipitated, filter the solution after it cools down, fold the filter paper into several layers, wrap it and set aside.

[0043] Place the encapsulated silver chloride precipitate in a crucible lined with 2g of sodium carbonate, then cover with 4g of sodium carbonate and 1.5g of sodium tetraborate decahydrate. Then, cover the crucible and place it in a muffle furnace. Heat the temperature uniformly to 455°C and hold for 30 minutes. After cooling naturally, remove the crucible and place it in a 200mL beaker. Add water to cover the crucible and boil until the salts are completely dissolved. Filter the precipitate, place it back in a clean beaker, add 10mL of water and 5mL of glacial acetic acid, and boil for 10 minutes. Remove the beaker and rinse the silver precipitate with water. Place the rinsed silver precipitate in a beaker, heat on a hot plate to dry, and weigh it (m²).

[0044] The silver content in pure silver is calculated according to the following formula:

[0045]

[0046] Example 2:

[0047] A method for detecting the silver content in pure silver comprises the following steps:

[0048] Weigh 0.50g of pure silver, record it as m1; put the weighed pure silver into a beaker, add water and nitric acid, heat until the silver is completely dissolved, then add an appropriate amount of hydrochloric acid to the beaker, cover and boil until the silver chloride is completely precipitated, filter the solution after it cools down, fold the filter paper into several layers, wrap it and set aside.

[0049] Place the wrapped silver chloride precipitate in a crucible covered with 2g of sodium carbonate, covered with 4g of sodium carbonate and 1.5g of sodium tetraborate decahydrate, then cover the crucible and place it in a muffle furnace, uniformly heat to 851°C, keep warm for 30 minutes, take out the crucible after natural cooling, place it in a 200mL beaker, add water to cover the crucible, heat and boil until the salts are completely dissolved, filter, take the filter residue silver particles and place them back in a clean beaker, add 10mL of water and 5mL of glacial acetic acid, and boil for 10 minutes; remove the beaker and wash the silver particles with water, put the washed silver particles into the beaker, place it on a hot plate to heat and dry, weigh it, and record it as m2.

[0050] The silver content in pure silver is calculated according to the following formula:

[0051]

[0052] Example 3:

[0053] A method for detecting the silver content in pure silver comprises the following steps:

[0054] Weigh 0.50g of pure silver and record it as m1;

[0055] Place the weighed pure silver into a beaker, add water and nitric acid, and heat until the silver is completely dissolved. Then add an appropriate amount of hydrochloric acid to the beaker, cover and boil until the silver chloride is completely precipitated. After the solution cools, filter it, fold the filter paper into several layers, wrap it and set aside.

[0056] Place the coated silver chloride in a crucible lined with 2g of sodium carbonate, then cover with 4g of sodium carbonate and 1.5g of sodium tetraborate decahydrate. Place the covered crucible in a muffle furnace and heat it uniformly to 1000°C for 30 minutes. After cooling naturally, remove the crucible and place it in a 200mL beaker. Add water to cover the crucible and boil until the salts are completely dissolved. Filter the residue, place the silver particles back in a clean beaker, add 10mL of water and 5mL of glacial acetic acid, and boil for 10 minutes. Remove the beaker and rinse the silver particles with water. Place the washed silver particles in a beaker, heat on a hot plate to dry, and weigh them (m²).

[0057] The silver content in pure silver is calculated according to the following formula:

[0058]

[0059] The test results of Examples 1 to 3 are shown in Table 1 below.

[0060] Table 1: Test results

[0061]

[0062]

[0063] From the analysis of the test data in Table 1, it can be seen that the method for detecting the silver content in pure silver provided in this application is highly operable and can accurately detect the silver content in pure silver.

[0064] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0065] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A method for checking the silver content in pure silver, characterized in that: The detection method comprises the following steps: Weigh the pure silver sample to the nearest 0.0001g and record it as m1; Place the weighed pure silver sample in a beaker, add water and nitric acid, heat until the silver is completely dissolved, then add an appropriate amount of chloride, cover and boil until the silver chloride is completely precipitated, filter after the solution cools, and wrap the silver chloride precipitate for later use; The wrapped silver chloride precipitate is placed in a crucible paved with reagents and covered with sodium carbonate and sodium tetraborate decahydrate; the crucible is then covered and placed in a muffle furnace, heated, and cooled naturally; After cooling, remove the crucible and place it in a 200mL beaker. Add water to cover the crucible and boil until the salts are completely dissolved. Then filter the liquid and place the silver particles on the filter paper back into a clean beaker for cleaning. Then place the cleaned silver particles into the beaker and heat and dry them on a hot plate to obtain the weight of the silver, which is recorded as m2. According to the calculation formula, the silver content in pure silver is calculated.

2. The detection method according to claim 1, characterized in that The calculation formula is as follows:

3. The detection method according to claim 1, wherein The chloride is at least one of hydrochloric acid, sodium chloride and potassium chloride.

4. The detection method according to claim 1, wherein The silver chloride precipitate is wrapped by a carbon-containing material, and the carbon-containing material is at least one of filter paper, plastic film, non-woven fabric and graphite paper.

5. The detection method according to claim 1, wherein The reagent is at least one of sodium carbonate, potassium carbonate and borax.

6. The detection method according to claim 1, characterized in that The heating treatment comprises the following steps: uniformly heating the temperature from room temperature to 455° C. to 1100° C., and keeping the temperature for 10 to 60 minutes.

7. The detection method according to claim 1, characterized in that The cleaning treatment uses an acetic acid aqueous solution.

8. The detection method according to claim 1, wherein The weight of silver can be obtained by weighing the filtrate directly after drying, or by adding 15 mL of hydrochloric acid to the filtrate, adjusting the volume to a 100 mL volumetric flask, and measuring the silver content using an air-acetylene flame at a wavelength of 328.1 nm using an atomic absorption spectrometer; or by using an inductively coupled plasma atomic emission spectrometer (ICP).

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