JPH04307355A - Formation of fine particles in inert gas blowing fine particle forming plasma emission spectral method - Google Patents

Abstract

PURPOSE:To achieve stable analysis and enhancement of accuracy regardless of the state of the surface of a molten metal by sampling the molten metal by a molten metal analyzing probe and immersing an inert gas blow nozzle in molten steel to form molten metal fine particles to subject said particles to plasma omission spectral analysis. CONSTITUTION:When a probe 1 is immersed in a molten metal 2, the thin metal plate closing an inflow port 3 is melted and the molten metal flows in from the inflow port. When the probe 1 is pulled up to stop, the surface 5 of the sampled molten metal is held to a constant surface by the position of the inflow port 3. An inert gas blow nozzle 7 is immersed in the molten metal 8 within a molten metal sampling container 6 to blow gas Ar in the molten metal to form fine particles which are, in turn, guided to a plasma emission spectral analyser from the end part of a fine particle discharge pipe 9. By this constitution, stable measurement can be performed without being affected by the change of the surface of the molten metal.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an analytical method for directly analyzing the composition of molten metal by blowing inert gas into molten metal to generate fine particles, and for directly analyzing the composition of molten metal by plasma emission spectroscopy. This paper relates to a method for generating fine particles suitable for direct analysis of molten metals used in the field of manufacturing process control and quality control analysis in industry.

0002

2. Description of the Related Art For manufacturing process control analysis in the metal manufacturing industry, spark emission spectroscopy is used to sample and solidify a block sample of molten metal. However, in recent years, especially in the iron mining industry, online real-time analysis of molten metals such as hot metal and molten steel has become increasingly necessary for faster manufacturing process control or operational control of new manufacturing processes such as multi-stage steelmaking. There is a strong need to develop a method.

[0003] For the above-mentioned purpose, a method (PH Scholes: BIS
RA Open Report MG/D, (1966
), P302, A. A. Rush: EUR Rep
Comm Eur Commu, No EUR-628
2 (1980)), various methods have been studied. However, none of these methods have ever been put into practical use at manufacturing sites, and have only been attempted on a laboratory scale. The present inventors also used a method for collecting fine particles by blowing inert gas (Japanese Patent Laid-Open No. 6
No. 0-219538), etc., and filed a patent application earlier.

In the case of the inert gas blowing method, it is necessary to control the gas discharge port to an optimal position below the hot water level, so it is effective when the hot water level fluctuations are relatively slow, but when the hot water level fluctuations are In severe cases, it was necessary to take measures to suppress the fluctuations, which was quite difficult to implement. Therefore, in order to solve these problems, the present inventors conducted further research, and as a result, published ``Particle conveying device for molten metal direct analysis device (Japanese Patent Application Laid-Open No. 63-30234).
” and “Direct analysis method of molten metal (JP-A-1-21589
8)" and filed a patent application.

[0005]

[Problems to be Solved by the Invention] However, as a result of further experiments and research by the present inventors, it was found that these inventions related to direct analysis methods for molten metals that generate fine particles by blowing inert gas do not require a suction pump due to the method of generating fine particles. It has been found that there is a problem in that it is necessary to attach accessory devices such as a pressure regulator to the probe, which complicates the mechanism of the probe body. That is, when attempting to analyze molten metal using the above method, an accessory device is required in addition to the original fine particle generation mechanism to always maintain a constant position of the molten metal in response to fluctuations in the molten metal level. An object of the present invention is to provide a method for producing fine particles for direct analysis of molten metals, which solves the above-mentioned problems.

[0006]

[Means for Solving the Problems] The present invention effectively solves the above problems, and the inventors have found that the following method is effective. In the above-mentioned inert gas injection particle generation plasma emission spectroscopy, a fixed amount of molten metal was sampled by simply immersing a molten metal analysis probe equipped with a molten metal collection container under the molten metal surface, and then sampled. The inert gas suction nozzle is lowered and immersed in the molten steel to blow inert gas such as Ar gas to generate molten metal fine particles to be analyzed, or
Molten metal fine particles are generated by simply immersing a molten metal analysis probe, which is equipped with a molten metal collection container into which inert gas is blown from an inert gas injection nozzle, under the surface of the molten metal. By making it possible to stably control the gas outlet to the optimal position below the molten metal surface regardless of the molten metal surface condition without installing the device on the probe, fine particles suitable for plasma emission spectroscopy are generated. A method for producing fine particles, characterized by carrying them out and analyzing them by plasma emission spectrometry.

[0007]

[Operations and Examples] The present invention will be explained in detail below. An example of a probe for analyzing molten steel used in the present invention is shown in FIG. In the analysis method of the present invention using this probe, first, the probe 1 for collecting fine particles shown in FIG. 1 is immersed in a metal bath of molten metal 2 for a certain period of time as shown in FIG. 2, and then lifted onto the metal bath. perform an action. By immersing the probe in the metal bath, the thin metal plate 4 that blocked the inlet 3 is melted, molten metal flows in from the molten metal inlet 3, and when the probe is pulled up and held still, the sampled molten metal is removed. The molten metal level 5 is kept constant by the position of the molten metal inlet 3. Thereafter, as shown in FIG. 3, an inert gas is blown into the inside 6 of the molten metal collecting container from an inert gas blowing nozzle 7, and after adjusting the atmosphere, the inert gas blowing nozzle 7 is immersed in the molten metal 8 collected. Generate fine particles.

Next, an example of generating fine particles using the molten steel analysis probe shown in FIG. 4 will be described. In the probe of FIG. 4, the inert gas blowing nozzle 10 is directly embedded in the container 6, without using the inert gas blowing nozzle that can be raised and lowered as shown in FIG. In the case of FIG. 4, first, inert gas is blown into the molten metal collection container 6 installed in the particulate collection probe 1 using the inert gas injection nozzle 10 for generating molten metal particulates, and the particulate transport pipe is The inside of the molten metal collection container 6 is made into an inert gas atmosphere while discharging the inert gas from the end of the molten metal collection container 9. Next, as shown in FIG. 5, the probe 1 for collecting fine particles is immersed in a metal bath of molten metal 8 for a certain period of time, and then lifted onto the metal bath. By immersing the probe in the metal bath, the thin metal plate 4 that shields the molten metal inlet 3 melts, and molten metal flows in from the inlet 3, as shown in FIG.
By raising the probe and keeping it stationary as shown in FIG. 2, the level 5 of the sampled molten metal is kept constant depending on the position of the molten metal inlet 3. At this time, since the inert gas is discharged from the inert gas injection nozzle, molten metal fine particles are generated as the molten metal level rises due to the inflow of molten steel.

Among the inert gas suction nozzles used in the method of the present invention, the nozzle 7 shown in FIG. 1 preferably has an inert gas blowing angle of approximately 45 degrees upward from the bottom. In this method, the molten metal level is always kept uniform depending on the position of the molten metal inlet 3, so there are basically no molten metal level fluctuations that can cause major errors in measurement, and as a result, the inert gas injection nozzle 7 If the vertical stroke of the molten metal analysis probe is controlled to a constant value depending on the position of the molten metal inlet 3 (in the case of FIG. 1), or if the vertical stroke of the molten metal analysis probe is controlled (in the case of FIG. 2),
It is possible to generate fine particles under always optimal fine particle generation conditions. The generated particles are guided to the plasma emission spectrometer by the internal pressure inside the probe from the end of the particle discharge pipe 9 facing the inside 6 of the molten metal collection container.

The major difference between the present invention and the conventional invention is that
With conventional methods, it was necessary to install a pressure control device near the probe to maintain constant control of the hot water level position, which has a large effect on analysis accuracy, but with this method, a complicated pressure control device can be installed. By making it possible to control the molten metal level at a constant level, the probe for molten metal analysis can be reliably immersed below the molten metal surface, regardless of whether the molten metal level fluctuates or not. This means that analysis is now possible. The example of FIG. 4 also has the advantage that the nozzle lifting device required in FIG. 1 is not required.

[0011]

[Effects of the Invention] By using the probe according to the present invention, analysis of molten metal components by inert gas injection, particulate generation plasma emission spectroscopy in iron and steel refining or non-ferrous refining can be performed using a probe with a simple structure that does not require any special accessory equipment. This has made it possible to perform stable measurements regardless of whether or not there are fluctuations in the level of the molten metal being measured, improving the accuracy of on-site operational management and quality control.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an example of a probe for measuring molten metal used in the present invention.

FIG. 2 is a schematic diagram of the molten metal measurement probe of FIG. 1 immersed in molten metal.

FIG. 3 is a schematic diagram of the case where analytical fine particles are generated by the molten metal measurement probe of FIG. 1.

FIG. 4 is a schematic diagram of another example of the probe for measuring molten metal used in the present invention.

FIG. 5 is a schematic diagram of the molten metal measuring probe shown in FIG. 4 immersed in molten metal.

FIG. 6 is a schematic diagram of the case where analytical fine particles are generated by the molten metal measurement probe of FIG. 4; 1 Probe for collecting fine particles 2 Molten metal 3 Molten metal inlet 4 Metal plate 5 Hot water level of collected molten metal 6 Molten metal collecting device 7, 10 Inert gas blowing nozzle 8 Collected molten metal 9 Particulate discharge pipe

Claims (2)

[Claims] Claim 1: In inert gas suction fine particle generation plasma emission spectroscopy, molten metal is collected with a molten metal analysis probe equipped with a molten metal collection container, and then an inert gas suction nozzle is immersed in the collected molten steel. A method for generating fine particles in inert gas injection fine particle generation plasma emission spectroscopy, characterized in that molten metal fine particles are generated, transported, and analyzed by plasma emission spectroscopy. [Claim 2] In inert gas inhalation fine particle generation plasma emission spectroscopy, a molten metal analysis probe equipped with a molten metal collection container is used, and an inert gas injection nozzle for fine particle generation is used to inject into the molten metal collection container. Fine particles used in inert gas blown fine particle generation plasma emission spectroscopy, which is characterized by immersing molten metal in molten metal while blowing an inert gas to generate, transport, and analyze molten metal fine particles using plasma emission spectroscopy. Generation method.