Method for rapidly dissolving ferroniobium

Abstract

The invention relates to a method for rapidly dissolving ferroniobium, which comprises the following steps: after ferroniobium is weighed, hydrofluoric acid and concentrated nitric acid are sequentially added to clarify the solution, and the purpose of adding hydrofluoric acid is that niobium is extremely easy to be hydrolyzed and precipitated, but Nb in a hydrofluoric acid system can exist in a stable soluble complex form; in the test, boric acid is added to mask F ions, and tartaric acid is added to inhibit Nb hydrolysis; in the dissolving process of ferroniobium, tartaric acid and boric acid must be added firstly, otherwise, the solution is directly turbid, and the experiment fails. In the ferroniobium dissolution process, Nb hydrolysis can be inhibited to generate niobic acid precipitates, F ions can be masked, the ferroniobium solution can be rapidly dissolved and clear, and the purpose of complete dissolution is achieved. Operation is simple, and dissolution is fast.

Description

Technical Field

[0001] The invention belongs to the technical field of metal materials, and in particular relates to a method for rapidly dissolving ferroniobium. Background Art

[0002] Ferroniobium is an essential alloy material for high-temperature steel and high-temperature alloy steel. It can improve high-temperature strength and refine grains. Ferroniobium combines with carbon to form carbides, which can eliminate the harmful effects of chromium carbide deposition in stainless steel.

[0003] As an additive in steel production, ferroniobium can effectively improve the performance and quality of steel, and significantly increase its strength and corrosion resistance. The application of ferroniobium is becoming more and more widespread, so the laboratory's testing requirements for ferroniobium materials must be fast and accurate. However, during the dissolution of ferroniobium, niobium is very easy to hydrolyze, and the niobium acid produced is solid, which cannot meet the rapid analysis requirements of the plasma spectrometer. Therefore, it is very necessary for the laboratory to explore a fast method for dissolving ferroniobium. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a method for rapidly dissolving ferroniobium, which has simple operation steps and high analysis efficiency.

[0005] In order to solve the above technical problems, the present invention provides a method for quickly dissolving ferroniobium, which is characterized in that firstly, a weighed ferroniobium powder sample is placed in a container, hydrofluoric acid is first added, and then concentrated nitric acid is added dropwise; then the solution in the container is heated until a precipitate just appears in the solution, tartaric acid is immediately added dropwise to the solution, and after the precipitate is completely dissolved, heating is continued to reduce the liquid volume of the solution; the dissolved reagents are placed in the air for natural cooling, and after the temperature reaches room temperature, tartaric acid is first added, and then boric acid is added; finally, the volumetric flask with the fixed volume is first shaken and then left to stand to complete the entire dissolution process of the ferroniobium sample.

[0006] Beneficial effects: The present invention provides a specific method that can be quantified and operated, which can inhibit the hydrolysis of Nb to generate niobate precipitation and mask F ions during the dissolution of ferroniobium, so that the ferroniobium solution can be quickly dissolved and clear, achieving the purpose of complete dissolution. The operation is simple and the dissolution is fast. DETAILED DESCRIPTION

[0007] In order to make the purpose, content and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below.

[0008] The present invention provides a method for rapidly dissolving ferroniobium, comprising the following steps:

[0009] S1. First, accurately weigh 0.1g of ferroniobium powder sample and place it in a gold crucible (or a polytetrafluoroethylene beaker). Use a pipette to add 2.5-3.5ml of hydrofluoric acid, and then use a disposable plastic dropper to drop 0.5-1.5mL of concentrated nitric acid into the solution.

[0010] S2. Next, place the gold crucible (or polytetrafluoroethylene beaker) on the laboratory hot plate for heating. When precipitation just appears in the solution, immediately take the acid-dripping operation, specifically, quickly add 5-7% tartaric acid to the solution. After the precipitation is completely dissolved, continue heating. The purpose of this step is to reduce the liquid volume of the solution to facilitate subsequent operations by the experimenter.

[0011] S3. Remove the dissolved reagent from the hot plate and place it in the air for natural cooling. When it reaches room temperature, add 18-22mL of 5-7% tartaric acid and transfer it to a 100mL volumetric flask. Then add 45-55mL of 4-6% boric acid and adjust the volume to the mark of the 100mL volumetric flask. This step is particularly critical. In the experiment, do not add boric acid first and then tartaric acid, otherwise the solution will become turbid, resulting in failure of ferroniobium dissolution.

[0012] S4. Finally, shake the volumetric flask and let it stand to complete the dissolution process of the ferroniobium sample.

[0013] After weighing the ferroniobium, place it in a gold crucible or a polytetrafluoroethylene beaker. In the experiment, hydrofluoric acid and concentrated nitric acid must be added in sequence to make the solution clear, otherwise precipitation is likely to occur directly. The purpose of adding hydrofluoric acid is that niobium is very easy to precipitate out of water, but in the hydrofluoric acid system, Nb can exist in the form of a stable soluble complex;

[0014] The purpose of adding boric acid in the experiment is to mask F ions, while the purpose of adding tartaric acid is to inhibit Nb hydrolysis. In the dissolution process of ferroniobium, the last step is particularly critical. It is absolutely forbidden to add boric acid first and then tartaric acid, otherwise the solution will become turbid directly, resulting in failure of the experiment.

[0015] Example:

[0016] The present invention provides a method for rapidly dissolving ferroniobium, comprising the following steps:

[0017] S1. First, accurately weigh 0.1g of ferroniobium powder sample and place it in a gold crucible (or a polytetrafluoroethylene beaker). Use a pipette to add 3ml of hydrofluoric acid, and then use a disposable plastic dropper to drop 1ml of concentrated nitric acid into the solution.

[0018] S2. Next, place the gold crucible (or polytetrafluoroethylene beaker) on the laboratory hot plate for heating. When precipitation just appears in the solution, immediately take the acid-dripping operation, specifically, quickly add 6% tartaric acid to the solution. After the precipitation is completely dissolved, continue heating. The purpose of this step is to reduce the liquid volume of the solution to facilitate subsequent operations by the experimenter.

[0019] S3. Remove the dissolved reagent from the hot plate and place it in the air for natural cooling. When it reaches room temperature, add 20mL of 6% tartaric acid and transfer it to a 100mL volumetric flask. Then add 50mL of 5% boric acid and adjust the volume to the mark on the 100mL volumetric flask. This step is particularly critical. In the experiment, do not add boric acid first and then tartaric acid, otherwise the solution will become turbid, resulting in failure of ferroniobium dissolution.

[0020] S4. Finally, shake the volumetric flask and let it stand to complete the dissolution process of the ferroniobium sample.

[0021] The present invention can inhibit the hydrolysis of Nb to generate niobic acid precipitation and mask F ions during the ferroniobium dissolution process, so that the ferroniobium solution can be quickly dissolved and clear, thereby achieving the purpose of complete dissolution.

[0022] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for rapidly dissolving ferroniobium, characterized in that: First, the weighed ferroniobium powder sample is placed in a container, and hydrofluoric acid is added first, and then concentrated nitric acid is added; then the solution in the container is heated until a precipitate just appears in the solution, and tartaric acid is immediately added to the solution. After the precipitate is completely dissolved, heating is continued to reduce the liquid volume of the solution; the dissolved reagents are placed in the air for natural cooling, and tartaric acid is added first and then boric acid when the temperature reaches room temperature. Finally, the volumetric flask with the fixed volume is shaken well and then left to stand to complete the entire dissolution process of the ferroniobium sample.

2. A method for rapidly dissolving ferroniobium according to claim 1, characterized in that: First, accurately weigh 0.1 g of ferroniobium powder sample and place it in a container.

3. The method for rapidly dissolving ferroniobium according to claim 1, characterized in that: The container is a gold crucible or a polytetrafluoroethylene beaker.

4. A method for rapidly dissolving ferroniobium according to claim 2, characterized in that: Add 2.5-3.5 ml of hydrofluoric acid.

5. The method for rapidly dissolving ferroniobium according to claim 2, characterized in that: Add 0.5-1.5 mL of concentrated nitric acid.

6. The method for rapidly dissolving ferroniobium according to claim 1, characterized in that: Add 18-22 mL of 5-7% tartaric acid and transfer to a 100 mL volumetric flask. Then add 45-55 mL of 4-6% boric acid and adjust the volume to the mark on the 100 mL volumetric flask.

7. The method for rapidly dissolving ferroniobium according to claim 1, characterized in that: Heat the container on a laboratory hot plate.

8. The method for rapidly dissolving ferroniobium according to claim 1, characterized in that: Add 3 ml of hydrofluoric acid.

9. The method for rapidly dissolving ferroniobium according to claim 1, characterized in that: Add 1 mL of concentrated nitric acid.

10. The method for rapidly dissolving ferroniobium according to claim 1, characterized in that: Add 20 mL of 6% tartaric acid and transfer to a 100 mL volumetric flask. Add 50 mL of 5% boric acid and adjust the volume to the mark on the 100 mL volumetric flask.