Method for determining silicon dioxide in quartz flux for copper smelting

Abstract

The invention belongs to the field of chemical detection, and particularly relates to a method for determining silicon dioxide in a quartz flux for copper smelting. The method specifically comprises the following steps: leaching with hot water, acidifying, adding potassium chloride, potassium fluoride and silicate into a strong acid solution to form potassium fluosilicate precipitate, hydrolyzing the potassium fluosilicate in the hot water, separating out hydrofluoric acid with equal amount of substance, and titrating with a sodium hydroxide standard titration solution by taking phenol red-bromothymol blue as an indicator, and calculating the mass fraction of silicon dioxide according to the volume of the consumed sodium hydroxide standard titration solution. According to the method, acid-base titration is adopted, and the process is short (3.5 hours). The method is a simple, convenient, rapid and low-cost chemical analysis method; and the detection range is 0.50%-99.9%.

Description

Technical Field

[0001] The invention belongs to the field of chemical detection, and in particular relates to a method for determining silicon dioxide in quartz flux used for copper smelting. Background Art

[0002] 1. Quartz flux is an important auxiliary material in the copper smelting process. The silicon dioxide content in it is usually between 70.0% and 99.9%. Its function is to separate copper from slag and purify copper by combining silicon dioxide and most impurity elements to form silicates during the smelting and blowing process of copper.

[0003] 2. Quartz flux usually includes different types such as quartz stone, quartz powder, quartz sand, etc., all of which are processed from natural rocks, river sand, etc. In recent years, with the upgrading of national environmental protection policies, the protection of rivers has been strengthened, and the mining of river sand has been greatly restricted. Therefore, the current quartz solvent is mainly quartz stone and quartz powder processed from rocks.

[0004] 3. Our factory purchases a large amount of quartz solvent for pyrometallurgy every year, most of which is quartz stone and quartz powder, and a small amount of gold- or silver-containing quartz sand. The silicon dioxide content in the quartz solvent is an important ingredient indicator, which is related to the safe and smooth operation of the pyrometallurgy process system and the realization of important technical and economic indicators such as "comprehensive recovery rate of copper smelting" and "copper content of flash slag".

[0005] As an industrial mineral raw material, quartz flux has a wide range of applications, including but not limited to glassmaking, refractory materials, and non-ferrous metal smelting. The silica content directly determines its purity and functionality, which in turn affects the quality and performance of the final product. Therefore, accurate silica content measurement is crucial for ensuring product quality, optimizing process flows, and improving market competitiveness. Summary of the Invention

[0006] The present invention discloses a method for determining silicon dioxide in quartz flux for copper smelting, so as to solve any of the above and other potential problems in the prior art.

[0007] In order to solve the above technical problems, the technical solution of the present invention is: a method for determining silicon dioxide in quartz flux for copper smelting, the method specifically comprising the following steps:

[0008] S1) The quartz flux sample to be measured is alkali-melted, leached with hot water, and acidified;

[0009] S2) placing the quartz flux sample acidified in S1) in a strongly acidic solution, adding a certain amount of potassium chloride and potassium fluoride to form a precipitate, filtering and washing, and then hydrolyzing in hot water;

[0010] S3) adding an indicator to the hydrolyzed solution obtained in S2), placing the solution in a medium, and then adding a standard sodium hydroxide solution for titration;

[0011] S4) Substituting the volume of the consumed sodium hydroxide standard titration solution obtained in S3) into the formula for calculating the mass fraction of silicon dioxide in the quartz flux.

[0012] Furthermore, the specific steps of S1) are:

[0013] S1.1) Weigh 0.1-0.2g of quartz flux and place it in a nickel crucible; then add 2-3g of alkali metal salt and dehydrate on an electric furnace;

[0014] S1.2) After dehydration, place the crucible in a muffle furnace preheated to 400°C and remove from the furnace when the temperature reaches 700°C.

[0015] S1.3) Hot leaching: Place the crucible in a PTFE beaker and blow in hot water. After the sample reacts, rinse the crucible with hot water to obtain the leaching solution.

[0016] Furthermore, the alkali metal salt is potassium hydroxide, sodium hydroxide or sodium peroxide.

[0017] Further, the specific steps of S2) are:

[0018] S2.1) Add 15-20 mL of concentrated nitric acid to the leached PTFE beaker and shake well, keeping the test solution volume between 40-60 mL.

[0019] S2.2) After the test solution has cooled to room temperature, add potassium chloride solid until saturated, allowing the crystals to spread 2 cm below the bottom of the cup. 2 , add 10mL of potassium fluoride solution dropwise, stirring while adding, and let it stand for 5-7 minutes;

[0020] S2.3) Using a plastic funnel, rinse the neutralization funnel and filter paper with detergent before filtering. Filter through medium-speed filter paper. Rinse the plastic beaker 2 to 3 times with detergent and wash the precipitate 3 times.

[0021] Furthermore, the concentrated acid in S2.1) is concentrated nitric acid.

[0022] Further, the specific steps of S3) are:

[0023] S4.1) Add 0.2-1 mL of indicator to the original beaker, place in 10 mL of medium, and neutralize with sodium hydroxide solution until purple. Place the filter paper and precipitate into the original plastic beaker, squeeze the filter paper, and wipe the beaker walls.

[0024] S4.2) Continue to neutralize with sodium hydroxide until it turns purple. Ignoring the volume of sodium hydroxide solution consumed, add 150-200 mL of boiled neutral sodium potassium tartrate solution or pure water at pH 7.

[0025] S4.3) While hot, titrate with standard sodium hydroxide solution until it turns purple. Perform a blank test with the sample. The solution temperature should not be lower than 70°C at the titration endpoint.

[0026] Furthermore, the indicator is a phenol red-bromothymol blue mixture; and the medium is a potassium chloride-ethanol solution.

[0027] Furthermore, the calculation formula in S4) is:

[0028]

[0029] Where: C NaoH is the actual concentration of the sodium hydroxide standard titration solution, mol / L; V1 is the volume of the sodium hydroxide standard solution consumed in the titration of the test solution, mL; V0 is the volume of the sodium hydroxide standard solution consumed in the titration of the blank, mL; m0 is the amount of quartz flux sample, g; M is the molar mass of SiO2.

[0030] Principle of the method: After alkali fusion, the sample is leached with hot water. After acidification, potassium chloride and potassium fluoride are added to a strong acidic solution to react with silicate to form potassium fluorosilicate precipitate. Potassium fluorosilicate is hydrolyzed in hot water to precipitate an equal amount of hydrofluoric acid. The solution is titrated with a standard sodium hydroxide solution using phenol red-bromothymol blue as an indicator. The mass fraction of silicon dioxide is calculated based on the volume of the standard sodium hydroxide solution consumed.

[0031] Compared with the prior art, the characteristics and beneficial effects of the present invention are:

[0032] 1. Currently, there is a silicate method for determining silicon dioxide, which uses a gravimetric method with a long process (2 days), while the present invention uses acid-base titration with a short process (3.5 hours).

[0033] 2. This method is greatly affected by the ambient temperature and humidity, and the entire process must be strictly operated in accordance with the conditions provided by the present invention.

[0034] 3. Provides a simple, fast and low-cost chemical analysis method.

[0035] 4. The detection range of the present invention is 0.50%-99.9%. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The present invention is a flowchart of a method for determining silicon dioxide in quartz flux for copper smelting. DETAILED DESCRIPTION

[0037] The technical solution of the present invention is further described in detail below through examples.

[0038] like Figure 1 As shown, the technical solution adopted by the present invention is: a method for determining silicon dioxide in quartz flux for copper smelting, the method comprising the following steps:

[0039] Step 1: Weigh the sample into a nickel crucible according to the sample weight, add 2g-3g of alkali metal salt, dehydrate the crucible on an electric furnace, shake the crucible from time to time to mix it thoroughly, then put it into a Muffle furnace that has been preheated to 400℃, and heat it to 700℃ before taking it out of the furnace.

[0040] Step 2: Move the crucible into a 300mL PTFE beaker, add a small amount of hot water, cover with a watch glass, and after the melt has finished reacting, pour the reactants in the crucible into a plastic beaker, rinse the crucible with water (total volume is about 40mL), add 15-20mL of nitric acid, and cool.

[0041] Step 3: Add potassium chloride solid until saturated and the crystals spread about 2cm on the bottom of the cup 2 , add 10mL of potassium fluoride solution (200g / L) dropwise, stirring while adding, and let it stand for 5-7 minutes.

[0042] Step 4: Use a plastic funnel. Before filtering, rinse the neutralization funnel and filter paper with washing liquid, filter with medium-speed filter paper, wash the plastic beaker 2 to 3 times with washing liquid, and wash the precipitate 3 times.

[0043] Step 5: Add 0.2-1.0 mL of phenol red-bromothymol blue mixed indicator and 10 mL of potassium chloride-ethanol solution to the original beaker (circle the solution along the side of the beaker). Neutralize with sodium hydroxide solution until the solution turns purple. Place the filter paper and precipitate back into the original plastic beaker, squeeze the filter paper, and wipe the beaker walls. Continue neutralizing with sodium hydroxide until the solution turns purple. The volume of the sodium hydroxide solution consumed is not counted.

[0044] Step 6. Add 150mL-200mL of boiling neutral potassium sodium tartrate solution or pure water with a pH of about 7, and while hot, add sodium hydroxide standard solution until the end point is purple. Perform a blank test along with the sample. The liquid temperature should not be lower than 70℃ at the titration end point.

[0045] Step 7: Calculate the results

[0046] Calculate the content according to the following formula:

[0047]

[0048] Where V1 is the volume of sodium hydroxide standard solution consumed by titrating the test solution, mL;

[0049] V0---the volume of sodium hydroxide standard solution consumed in the titration blank, mL;

[0050] M0---weigh the sample amount, g;

[0051] M---molar mass of SiO2;

[0052] c NaOH --The actual concentration of the sodium hydroxide standard titration solution, mol / L;

[0053] 1. Reagents and utensils

[0054] Unless otherwise stated, only reagents of confirmed analytical grade and distilled or deionized water or water of equivalent purity were used in the analyses.

[0055] 2.1 Potassium hydroxide

[0056] 2.2 Potassium chloride

[0057] 2.3 Nitric acid (ρ1.42 g / mL)

[0058] 2.4 Hydrochloric acid (1+1)

[0059] 2.5 Potassium fluoride solution (200g / L): Dissolve 100g potassium fluoride in 300mL of water, add 100mL of nitric acid, add potassium chloride until saturated, dilute to 500mL with water, and shake well. After 30 minutes, filter and store in a plastic bottle for later use.

[0060] 2.6 Washing solution: Weigh 250g potassium chloride in 4000mL water, add 1000mL ethanol, dilute to 5000mL with water, add a little mixed indicator, and neutralize with sodium hydroxide until purple

[0061] 2.7 Potassium chloride-ethanol solution: Weigh 5 g potassium chloride into 50 mL water, add 50 mL ethanol, and mix well.

[0062] 2.8 Potassium sodium tartrate solution (10g / L): Weigh 10g of potassium sodium tartrate and dissolve it in 1L of water. After boiling, add a few drops of mixed indicator and neutralize with sodium hydroxide until the solution turns purple.

[0063] 2.9 Sodium hydroxide standard titration solution (C NaOH ≈0.2mol / L)

[0064] 2.10 Phenol red-bromothymol blue mixed indicator (1g / L): Dissolve 0.1g of each indicator in 50mL of ethanol and 50mL of water and mix thoroughly. Store at a temperature not exceeding 25°C. It is best to prepare it before use.

[0065] 2.11 Beaker, funnel and stirring rod are all made of plastic.

[0066] Example 1

[0067] This embodiment includes the following steps:

[0068] Step 1: Weigh 0.1000 g of national standard material (siliceous sandstone) GBW03114, add 2 g of potassium hydroxide, dehydrate the crucible on an electric furnace, shake the crucible from time to time to mix it thoroughly, then put it into a Muffle furnace preheated to 400°C, take it out of the furnace when it reaches 700°C, and cool it down.

[0069] Step 2: Move the crucible into a 300mL PTFE beaker, add a small amount of hot water, cover with a watch glass, and after the melt has reacted, pour the reactants in the crucible into a plastic beaker, rinse the crucible with water (total volume is about 40mL), add 15mL of nitric acid, and cool.

[0070] Step 3: Add potassium chloride solid until saturated and the crystals spread about 2cm on the bottom of the cup 2 , add 10mL of potassium fluoride solution (200g / L) dropwise, stirring while adding, and let it stand for 5-7 minutes.

[0071] Step 4: Use a plastic funnel. Before filtering, rinse the neutralization funnel and filter paper with washing liquid, filter with medium-speed filter paper, wash the plastic beaker 2 to 3 times with washing liquid, and wash the precipitate 3 times.

[0072] Step 5: Add 0.5 mL of phenol red-bromothymol blue mixed indicator and 10 mL of potassium chloride-ethanol solution to the original beaker (circle the solution along the side of the beaker). Neutralize with sodium hydroxide solution until the solution turns purple. Place the filter paper and precipitate back into the original plastic beaker, squeeze the filter paper, and wipe the beaker walls. Continue neutralizing with sodium hydroxide until the solution turns purple. The volume of sodium hydroxide solution consumed is not counted.

[0073] Step 6. Add 200 mL of boiling neutral potassium sodium tartrate solution or pure water with a pH of about 7, and titrate with sodium hydroxide standard solution while hot until the solution turns purple, consuming 29.80 mL of standard solution. The liquid temperature should not be lower than 70°C at the titration endpoint.

[0074] Step 7: Perform a blank test along with the sample. The blank consumption of this method is 0.00 mL of standard solution.

[0075] Step 8. Calculate the results

[0076]

[0077] Where V1 is the volume of sodium hydroxide standard solution consumed by titrating the test solution, mL;

[0078] V0---the volume of sodium hydroxide standard solution consumed in the titration blank, mL;

[0079] M0---weigh the sample amount, g;

[0080] N--molar mass of SiO2;

[0081] c NaOH --The actual concentration of the sodium hydroxide standard titration solution, mol / L;

[0082] The SiO2(%) of this sample is calculated to be 89.52%, and the fixed value is 89.59%. The results are consistent and accurate and reliable.

[0083] Example 2

[0084] This embodiment includes the following steps:

[0085] Step 1: Weigh 0.1000 g of national standard material (siliceous sandstone) GBW03113, add 2 g of potassium hydroxide, dehydrate the crucible on an electric furnace, shake the crucible from time to time to mix it thoroughly, then put it into a Muffle furnace preheated to 400°C, take it out of the furnace when it reaches 700°C, and cool it down.

[0086] Step 2: Move the crucible into a 300mL polytetrafluoroethylene beaker, add a small amount of hot water, cover with a watch glass, and after the melt has reacted, pour the reactants in the crucible into a plastic beaker, rinse the crucible with water (total volume is about 40mL), add 15mL of nitric acid, and cool.

[0087] Step 3: Add potassium chloride solid until saturated and the crystals spread about 2cm on the bottom of the cup 2 , add 10mL of potassium fluoride solution (200g / L) dropwise, stirring while adding, and let it stand for 5-7 minutes.

[0088] Step 4: Use a plastic funnel. Before filtering, rinse the neutralization funnel and filter paper with washing liquid, filter with medium-speed filter paper, wash the plastic beaker 2 to 3 times with washing liquid, and wash the precipitate 3 times.

[0089] Step 5: Add 0.5 mL of phenol red-bromothymol blue mixed indicator and 10 mL of potassium chloride-ethanol solution to the original beaker (circle the solution along the side of the beaker). Neutralize with sodium hydroxide solution until the solution turns purple. Place the filter paper and precipitate back into the original plastic beaker, squeeze the filter paper, and wipe the beaker walls. Continue neutralizing with sodium hydroxide until the solution turns purple. The volume of sodium hydroxide solution consumed is not counted.

[0090] Step 6. Add 200 mL of boiling neutral potassium sodium tartrate solution or pure water with a pH of about 7, and titrate with sodium hydroxide standard solution until the solution turns purple while hot. 31.37 mL of standard solution is consumed. The liquid temperature should not be lower than 70°C at the titration endpoint.

[0091] Step 7: Perform a blank test along with the sample. The blank consumption of this method is 0.00 mL of standard solution.

[0092] Step 8. Calculate the results

[0093]

[0094] Where V1 is the volume of sodium hydroxide standard solution consumed by titrating the test solution, mL;

[0095] V0---the volume of sodium hydroxide standard solution consumed in the titration blank, mL;

[0096] M0---weigh the sample amount, g;

[0097] M--molar mass of SiO2;

[0098] c NaOH --The actual concentration of the sodium hydroxide standard titration solution, mol / L;

[0099] The calculated SiO2(%) of this sample is 94.24%, and the fixed value is 94.41%. The results are consistent and accurate and reliable.

[0100] The above describes in detail a method for determining silica in quartz flux for copper smelting, as provided in the examples of this application. The description of the above examples is intended only to facilitate understanding of the method and core concept of this application. Furthermore, those skilled in the art will appreciate that variations in the specific implementation and scope of application may occur based on the concepts of this application. In summary, this specification should not be construed as limiting this application.

[0101] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different nouns to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. For example, "including" and "comprising" mentioned throughout the specification and claims are open-ended terms, so they should be interpreted as "including / including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problems within a certain error range and basically achieve the technical effects. The subsequent description in the specification is a preferred embodiment of the present application, but the description is for the purpose of illustrating the general principles of the present application, and is not used to limit the scope of the present application. The scope of protection of the present application shall be as defined in the attached claims.

[0102] It should also be noted that the terms "include," "comprises," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a product or system comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such product or system. In the absence of further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the product or system comprising the element.

[0103] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0104] The above description shows and describes several preferred embodiments of the present application. However, as previously mentioned, it should be understood that the present application is not limited to the form disclosed herein and should not be construed as excluding other embodiments. Instead, the present application can be used in various other combinations, modifications, and environments and can be modified within the scope of the application concept described herein through the above teachings or technology or knowledge in the relevant field. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present application should be protected by the claims appended hereto.

Claims

1. A method for determining silicon dioxide in quartz flux for copper smelting, characterized in that: The method specifically comprises the following steps: S1) alkali-melting the quartz flux sample to be measured, leaching it with hot water, and acidifying it; S2) placing the quartz flux sample acidified in S1) in a strongly acidic solution, adding a certain amount of potassium chloride and potassium fluoride to form a precipitate, filtering and washing, and then hydrolyzing in hot water; S3) adding an indicator to the hydrolyzed solution obtained in S2), placing the solution in a medium, and then adding a standard sodium hydroxide solution for titration; S4) Substituting the volume of the consumed sodium hydroxide standard titration solution obtained in S3) into the formula for calculating the mass fraction of silicon dioxide in the quartz flux.

2. The method according to claim 1, characterized in that The specific steps of S1) are: S1.1) Weigh 0.1-0.2g of quartz flux and place it in a nickel crucible; then add 2-3g of alkali metal salt and dehydrate on an electric furnace; S1.2) After dehydration, place the crucible in a muffle furnace preheated to 400°C and remove from the furnace when the temperature reaches 700°C. S1.3) Hot leaching: Place the crucible in a PTFE beaker and blow in hot water. After the sample reacts, rinse the crucible with hot water to obtain the leaching solution.

3. The method according to claim 2, characterized in that The alkali metal salt is potassium hydroxide, sodium hydroxide or sodium peroxide.

4. The method according to claim 1, wherein The specific steps of S2) are: S2.1) Add 15-20 mL of concentrated nitric acid to the leached PTFE beaker and shake well, keeping the test solution volume between 40-60 mL. S2.2) After the test solution has cooled to room temperature, add potassium chloride solid until saturated, allowing the crystals to spread 2 cm below the bottom of the cup. 2 , add 10mL of potassium fluoride solution dropwise, stirring while adding, and let it stand for 5-7 minutes; S2.3) Using a plastic funnel, rinse the neutralization funnel and filter paper with detergent before filtering. Filter through medium-speed filter paper. Rinse the plastic beaker 2 to 3 times with detergent and wash the precipitate 3 times.

5. The method according to claim 1, wherein The concentrated acid in S2.1) is concentrated nitric acid.

6. The method according to claim 1, characterized in that The specific steps of S3) are: S4.1) Add 0.2-1 mL of indicator to the original beaker, place in 10 mL of medium, and neutralize with sodium hydroxide solution until purple. Place the filter paper and precipitate into the original plastic beaker, squeeze the filter paper, and wipe the beaker walls. S4.2) Continue to neutralize with sodium hydroxide until it turns purple. Ignoring the volume of sodium hydroxide solution consumed, add 150-200 mL of boiled neutral sodium potassium tartrate solution or pure water at pH 7. S4.3) While hot, titrate with standard sodium hydroxide solution until it turns purple. Perform a blank test with the sample. The solution temperature should not be lower than 70°C at the titration endpoint.

7. The method according to claim 6, characterized in that The indicator is a phenol red-bromothymol blue mixed solution; and the medium is a potassium chloride-ethanol solution.

8. The method according to claim 1, characterized in that The calculation formula in S4) is: Where: C NaoH is the actual concentration of the sodium hydroxide standard titration solution, mol / L; V1 is the volume of the sodium hydroxide standard solution consumed in the titration of the test solution, mL; V0 is the volume of the sodium hydroxide standard solution consumed in the titration of the blank, mL; m0 is the amount of quartz flux sample, g; M is the molar mass of SiO2.

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