Method for determining silicon dioxide in covering agent

Abstract

The invention discloses a method for measuring silicon dioxide in a covering agent, which is characterized by comprising the following steps of: decomposing a sample by using a mixed solvent, extracting by using hydrochloric acid, dehydrating polyoxyethylene to separate silicon dioxide from other metal ions, filtering, firing, and weighing to a constant amount, thereby measuring the content of silicon dioxide. The invention aims to provide a method for measuring silicon dioxide in a covering agent so as to solve the problem that no method for detecting silicon dioxide in the covering agent exists.

Description

Technical Field

[0001] The invention belongs to the technical field of covering agent analysis, and in particular relates to the determination of silicon dioxide in a covering agent. Background Art

[0002] In steel production, silicon dioxide (SiO2) as the main component of the covering agent has many important functions: 1. Promote slag formation: During the steelmaking process, silicon dioxide can react with substances such as iron oxide to form slag. Slag is an indispensable part of the steelmaking process. It can absorb undesirable impurities and metallurgical reaction products in the molten steel to ensure the purity and quality of the molten steel. The higher the content of silicon dioxide in the slag, the higher the content of the slag, which promotes the formation of slag. 2. Improve the consistency and fluidity of the slag: silicon dioxide can increase the viscosity and fluidity of the slag. In the slag, the presence of silicon dioxide will increase the viscosity of the slag, making it easier for the slag to drip into the molten steel, achieving the purpose of purifying the molten steel. At the same time, it can also make the slag denser, so as to better wrap and extract non-metallic inclusions in the steel and ensure the purity of the steel. 3. Reduction and deoxidation: During the steelmaking process, silicon dioxide can undergo reduction reactions with substances such as iron oxide to reduce to compounds such as SiO and SiO2. These compounds can effectively reduce the iron content in the slag, thereby improving the reducibility of the slag. At the same time, it can also remove oxides in the molten steel, thereby reducing inclusions and improving the quality of the steel. 4. Prevent oxidation of molten steel: Silicon dioxide can also prevent oxidation and reduction or reduction reactions in the molten steel during steelmaking. In the continuous casting process, silicon dioxide can also play a role similar to a cutting machine, cutting off the continuous outflow of molten steel, thereby maintaining the stability of the molten steel shape.

[0003] Therefore, accurate analysis of the silicon dioxide content in the covering agent is an important part of controlling the quality of steel products. To this end, we have invented an analysis method for the silicon dioxide content in the covering agent. Summary of the invention

[0004] The purpose of the present invention is to provide a method for determining silicon dioxide in a covering agent, so as to solve the problem that there is no detection method for silicon dioxide in the covering agent.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] The present invention provides a method for determining silicon dioxide in a covering agent, comprising: decomposing the sample with a mixed solvent, extracting with hydrochloric acid, dehydrating with polyethylene oxide to separate silicon dioxide from other metal ions, filtering, burning, and weighing to a constant weight, thereby determining the content of silicon dioxide.

[0007] 2. The method of claim 1, wherein the method comprises:

[0008] Weigh 0.2500g of sample into a platinum crucible pre-mixed with 2.5-3g of mixed solvent, mix well with a glass rod, cover the surface with a small amount of mixed solvent, melt in a muffle furnace at 850-900℃ for 15-20min, put into a 400mL beaker after cooling, add 50mL of hydrochloric acid to extract the frit, and wash out the crucible with hot water. Concentrate the solution after extracting the frit to nearly dryness, wipe the glass rod and the side wall of the beaker with filter paper, add 20mL of polyethylene oxide, stir well, crush the lumps with a glass rod, let stand for 5-10min, add 50mL of hot water to dissolve the salts, filter with medium-speed quantitative filter paper, wash the beaker, wash with hot hydrochloric acid until there is no iron ion, and then wash with hot water until there is no chloride ion.

[0009] Transfer the precipitate together with the filter paper into a porcelain crucible, carbonize and ashed, burn at 1000±50℃ for 30-50min, take out, cool to room temperature, and weigh; repeat burning and weighing until constant weight;

[0010] Calculation of analysis results:

[0011]

[0012] Where: m1: sample sediment mass (g)

[0013] m0: Blank precipitate mass (g)

[0014] m: sample mass (g).

[0015] Furthermore, 2.5 g of crystalline aluminum chloride was added to the fluorine-containing sample.

[0016] Furthermore, the concentration of polyethylene oxide is 2 g / L.

[0017] Further, 50 mL of 70-80°C hot water was added to dissolve the salts.

[0018] Further, the sample was calcined at 1000°C for 40 minutes and then taken out.

[0019] Furthermore, during carbonization burning, the furnace door should be opened and burned for 10 minutes before closing the furnace door.

[0020] Compared with the prior art, the beneficial technical effects of the present invention are:

[0021] 1) Fast, efficient and low-cost: This method greatly shortens the operation process, saves drugs, reduces testing costs and improves production efficiency.

[0022] 2) Accurate and stable: Accurate and stable: Using this method, the measurement results are stable and the data are accurate.

[0023] 3) Currently, there is a lack of relevant detection methods. This method provides accurate data for the content of silicon dioxide in the covering agent, filling the gap in the determination of the content of silicon dioxide in the covering agent. DETAILED DESCRIPTION

[0024] A method for determining silicon dioxide in a covering agent comprises:

[0025] 1 Main instruments and reagents

[0026] Mixed solvent: grind two parts of anhydrous sodium carbonate and one part of boric acid into powder and mix well;

[0027] Hydrochloric acid (ρ1.19)(1+1)(5+95);

[0028] Polyethylene oxide solution (2 g / L);

[0029] Weigh 0.2g polyethylene oxide, add 100mL water, stir to dissolve (prepare when needed);

[0030] Crystalline aluminum chloride (solid);

[0031] Silicon standard solution (1000 μg / mL).

[0032] 2 Experimental methods

[0033] 2.1 Blank test

[0034] Carry out a blank test along with the sample.

[0035] 2.2 Determination

[0036] Weigh 0.2500g of sample into a platinum crucible pre-mixed with 2.5-3g of mixed solvent, mix well with a glass rod, cover the surface with a small amount of mixed solvent, melt in a muffle furnace at 850-900℃ for 15-20min, cool and put into a 400mL beaker (fluorine-containing sample plus 2.5g of crystallized aluminum chloride [1] ), add 50mL hydrochloric acid (1+1) to soak the frit, and wash out the crucible with hot water. Concentrate the solution after soaking the frit to nearly dry (wet salt state), wipe the glass rod and the side wall of the beaker with filter paper, add 20mL polyethylene oxide (2g / L), stir evenly, crush the lumps with a glass rod, let it stand for 5-10 minutes, add 50mL hot water (70-80℃) to dissolve the salts, filter with medium-speed quantitative filter paper, wash the beaker, wash with hot hydrochloric acid (5+95) until there is no iron ion, and then wash with hot water until there is no chloride ion.

[0037] Transfer the precipitate and filter paper into a porcelain crucible and carbonize it. [2] , ash, burn at 1000℃ for 40min, take out, cool to room temperature, weigh [3] Repeatedly burn and weigh until constant weight is reached.

[0038] Note [1]: If there is no crystalline aluminum chloride, 0.3 g of pure aluminum can be used instead, pre-dissolved in the acid used.

[0039] [2]: During carbonization, the furnace door should be opened and burned for 10 minutes before closing.

[0040] [3]: Weigh immediately after cooling.

[0041] 2.3 Calculation of analysis results

[0042]

[0043] Where: m1: sample sediment mass (g)

[0044] m0: Blank precipitate mass (g)

[0045] m: sample mass (g)

[0046] 3 Results and discussion

[0047] 3.1 Precision of the method

[0048] The same sample was measured 11 times continuously to verify the precision of the method, as shown in Table 1.

[0049] Table 1 Method precision experiment

[0050]

[0051] As can be seen from the above table, the RSDs are all less than 1%, so they have good precision.

[0052] 3.2 Accuracy of the method

[0053] The present invention uses the accuracy of the standard addition recovery determination method when there is no suitable standard sample. When determining silicon, a silicon standard solution is added. The corresponding addition amount is shown in Table 2.

[0054] Table 2 Method accuracy experiment

[0055]

[0056] It can be seen from Table 2 that the invention can ensure the accuracy of the test results.

[0057] 4. Conclusion

[0058] A large amount of experimental data shows that the present invention provides a reliable new analytical method for determining silicon dioxide in covering agents. The method has the advantages of simple operation, easy mastery, high accuracy and precision of the measurement results, and can fully meet the requirements of detection and analysis, and provide accurate data of its composition for the use of covering agents.

[0059] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for determining silicon dioxide in a covering agent, characterized in that: include: The sample is decomposed with a mixed solvent, extracted with hydrochloric acid, dehydrated with polyethylene oxide to separate silicon dioxide from other metal ions, and then filtered, burned, and weighed to a constant weight, thereby measuring the silicon dioxide content.

2. The determination of silicon dioxide in the covering agent according to claim 1, characterized in that: Specifically include: Weigh 0.2500g of sample into a platinum crucible pre-mixed with 2.5-3g of mixed solvent, mix well with a glass rod, cover the surface with a small amount of mixed solvent, melt in a muffle furnace at 850-900℃ for 15-20min, put into a 400mL beaker after cooling, add 50mL of hydrochloric acid to extract the frit, and wash out the crucible with hot water. Concentrate the solution after extracting the frit to nearly dryness, wipe the glass rod and the side wall of the beaker with filter paper, add 20mL of polyethylene oxide, stir well, crush the lumps with a glass rod, let stand for 5-10min, add 50mL of hot water to dissolve the salts, filter with medium-speed quantitative filter paper, wash the beaker, wash with hot hydrochloric acid until there is no iron ion, and then wash with hot water until there is no chloride ion. Transfer the precipitate together with the filter paper into a porcelain crucible, carbonize and ashed, burn at 1000±50℃ for 30-50min, take out, cool to room temperature, and weigh; repeat burning and weighing until constant weight; Calculation of analysis results: Where: m1: sample sediment mass (g) m0: Blank precipitate mass (g) m: sample mass (g).

3. The determination of silicon dioxide in the covering agent according to claim 2, characterized in that: Add 2.5 g of crystalline aluminum chloride to the fluorine-containing sample.

4. The determination of silicon dioxide in the covering agent according to claim 1, characterized in that: The concentration of polyethylene oxide was 2 g / L.

5. The determination of silicon dioxide in the covering agent according to claim 1, characterized in that: Add 50 mL of 70-80°C hot water to dissolve the salts.

6. The determination of silicon dioxide in the covering agent according to claim 1, characterized in that: Burn at 1000℃ for 40min and take out.

7. The determination of silicon dioxide in the covering agent according to claim 1, characterized in that: During carbonization burning, the furnace door should be opened and burned for 10 minutes before closing the furnace door.

Images