JPS6027847A - Preparation of specimen for fluorescent x-ray analysis - Google Patents

Abstract

PURPOSE:To prevent damage on the surface of a crucible, by preparing a glass- bead specimen by charging consecutively flux, combustible fibrous material, powder specimen and flux into a Pt crucible and allowing the charge to be heated and melted in a sandwich condition by the flux. CONSTITUTION:On the bottom of a Pt crucible 1 a layer 2 of flux (for example, sodium borate) of the specified quantity (4-6 times of the specimens) is spread and combustible fibrous material (for example, filter paper) is spread and on top of the composite layer. A mass of powder specimen 4 (iron are, blast-furnace slug. convertor slug, sintered ore, etc.) of the specified quantity is charged in a layer in such a way that the charge contacts the inner periphery of the Pt crucible and the top surface of the powder specimen is covered and the specified quantity of peeling agent 5 is added. Thus, the powder specimen and the combustible fibrous material are made in the sandwich condition with the flux and after the charge is heated and melted without allowing the powder specimen to contact the Pt crucible and a glass-bead specimen is prepared by normal temperature cooling. Thus, any damage of the crucible surface is prevented.

Description

[Detailed description of the invention] It is something that

Conventionally, fluorescent X-ray analysis has been employed as a method for quantifying the component content of powder samples such as iron ore, blast furnace slag, converter slag, and sintered ore. This fluorescent X-ray analysis method is used for sample K.
When X-rays are irradiated, secondary X-rays specific to the element are generated, and the component content is determined by detecting the amount of secondary X-rays generated. Conventionally, press-molded powder samples have been used as analysis samples, but errors occur in quantitative values due to the influence of mineral history, particle size, coexisting elements, etc.

Therefore, in order to reduce these error factors and improve the accuracy of analysis, a method of melting the sample has been adopted.

The above-mentioned melting method involves weighing out a crushed sample and a certain amount of sodium borate, placing them in a platinum-platinum (5%) crucible, adding a release agent, and then heating them in a heating furnace (for example, at 7086°C).
) for several 79 minutes, and after cooling, the glass bead sample was peeled off from the platinum rutsuho, the contact part with the bottom of the platinum rutsuho faced upward, and quantification was performed by irradiating it with X-rays.

The samples to be analyzed are not necessarily all oxides like natural minerals, and some may contain substances that form alloys with platinum. If such a sample is directly melted as described above, it will form an alloy with platinum and the platinum will be severely corroded. If the platinum is attacked, it may need to be polished or recast, depending on the degree of attack.

In order to solve the above problem, combustible fiber material (filter paper,
Place a powder sample on top of it (plane waste, cloth, gauze, etc.), open the door of the heating furnace (electric furnace, high-frequency heating furnace, etc.), and leave the flammable fiber material to burn (preliminary roasting). After the flame is extinguished, close the door of the furnace, take out the platinum crucible after 3 to 3 minutes, and add a melting agent (for example, boric acid).
A method has been proposed in which glass bead samples are prepared by adding a certain amount (5 to 78 times the amount of Jum) to the sample, mixing it, charging it into a heating furnace again, and heating and melting it.

For example, in the case of blast furnace slag, since the iron content is low, this method only requires a thin film to be applied to the bottom of the platinum crucible.
This is an excellent method that has the effect of significantly reducing the degree of damage compared to conventional methods.

However, in this method, a powder sample is placed on a combustible fiber material, pre-roasted, the pre-roasted powder sample and a melting agent are mixed, and the powder sample and melting agent are heated and melted. When mixed, a portion of the powder sample comes into direct contact with the platinum crucible. Therefore, if the powder sample is in direct contact with this platinum crucible, especially if it is converter slag with a high iron content, it will form an alloy with the platinum crucible and will be in a state where it can easily dissolve, thereby eliminating damage to the platinum crucible. The disadvantage is that it cannot be done.

In order to solve the above-mentioned problems, the present invention has been developed as a result of various studies on the conditions for heating and melting the powder sample with a melting agent without direct contact between the platinum crucible and the powder sample. First, charge a melting agent, a combustible fiber material, a powder sample, and a melting agent from the bottom in this order, and heat and melt the combustible material and powder sample in a sandwich state using the melting agent. It has been found that the thin film formed on the bottom of the platinum crucible and the formation of alloys with the platinum crucible can be significantly reduced.

By obtaining a glass bead sample using the sample preparation method for fluorescent X-ray analysis as described above, it is possible to prevent significant damage to the surface of the platinum crucible even when using converter slag with a high iron content, which was a problem with conventional methods. In addition, the preliminary roasting process can be omitted.

Hereinafter, the invention will be specifically congratulated based on the drawings. FIG. 1 is a cross-sectional view showing a platinum crucible, a powder sample, a melting agent, a stripping agent, and the like charged therein before preparing a sample for fluorescent X-ray analysis in an embodiment of the present invention.

First, on the bottom of a platinum crucible, spread a fixed amount of melting agent 2 (e.g., sodium borate) (6 times the amount of glue for the sample), then spread a combustible fiber material 3 (e.g., filter paper), and place powder on top of it. A certain amount (usually θ3 to /θ2) of the sample (iron ore, blast furnace slag, converter slag, sintered ore, etc.) is placed in a layer, and then a certain amount of melting agent (same as in 2) is placed on top of it. (9 to 6 times the amount of the sample) was added in a layer so as to be in contact with the periphery of the platinum crucible and to cover the top surface of the powder sample, and release agent j (
e.g. sodium iodide) (usually combined with a melting agent and two
30 +nlF) is added to the

In this way, the powder sample and the combustible fiber material are sandwiched with a melting agent, and the powder sample and platinum crucible are heated and melted without direct contact with each other to achieve complete oxidation.

Furthermore, the platinum crucible was placed in a heating furnace heated to 7,000 to 7,050°C, the door was closed, and melted for about 75 minutes.Then, the door of the heating furnace was opened, the platinum crucible was taken out, and the platinum crucible was placed at room temperature. Allow to cool to prepare a glass bead sample with a predetermined shape. The glass bead sample prepared by the above method is peeled off from the platinum crucible and analyzed using a fluorescent X-ray analyzer.

Next, specific examples of the method of the present invention will be shown.

Example: Place boric acid on the bottom of a platinum crucible) IJ Umgu 2 is spread, filter paper is placed on top of it, powder sample θg2 is placed on top of it in a layer, and sodium borate DA 2 is placed on top of it so as to be in contact with the periphery of the platinum crucible. After adding 30 my of sodium iodide to the powder sample,
The mixture is placed in a heating furnace heated to /θθ0 to /θSθ°C, the door is closed, and melted for 7.5 minutes. After that, the door of the heating furnace was opened, the platinum crucible was taken out, the platinum crucible was left to cool at room temperature, and the obtained glass bead sample was peeled off from the platinum crucible.
Analysis was performed using a fluorescent X-ray analyzer.

According to this example, in the conventional method (JP-A-Sho, FF7-5 Google Otsu No. 2), there was significant damage to the surface of the platinum crucible, such as spotty alloy formation or thin coating. Even with a large amount of powder sample (for example, converter slag), no damage to the platinum crucible was observed, and satisfactory results were obtained in terms of analysis accuracy.

According to the method of the present invention, it is possible to prevent significant damage to the surface of a platinum crucible that occurs when heating and melting a powder sample such as converter slag with a high iron content as described above. As a result (1) The number of times of polishing and recasting for repairing a damaged platinum crucible can be reduced to 5 minutes/less than that of the conventional method, and the durability of the platinum crucible is significantly improved.

(2) Workability is improved because the preliminary roasting step in the conventional method can also be omitted.

It has the following effects.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a platinum crucible used for preparing samples for fluorescent X-ray analysis, and the state in which melting agents, combustible fiber materials, powder samples, stripping agents, etc. are charged. /... Platinum melting agent 2... Melting agent 3... Flammable fiber material G... Powder sample S... Stripping agent 7- Figure J

Claims (1)

[Claims] A melting agent, a combustible fiber material, a powder sample, and a melting agent are sequentially charged into a platinum crucible, and the combustible material and powder sample are heated and melted in a sandwich state using the melting agent to prepare a glass bead sample. A sample preparation method for fluorescent X-ray analysis.