JPH0313531A - Method for solubilizing ruthenium - Google Patents

Abstract

PURPOSE:To efficiently recover Ru from Ru scraps or Ru oxide in the form of an aq. soln. by allowing the Ru scraps or Ru oxide to react with chlorine at a high temp., capturing the resulting volatile chloride with a specified capturing agent and carrying out treatment with water. CONSTITUTION:Ru scraps or Ru oxide 1 such as RuO4 is packed into a reaction tube 2 contg. silica sand 5 for heating gaseous chlorine, porous ceramics 4 and a ceramic filter 3 on the sand 5. An outer tube 10 is set around the tube 2 and an Ru chloride capturing agent 9 such as BaCl2, KCl, NaCl or CaCl2 is filled into the tube 10. Gaseous chlorine 6 is fed into the tube 2 from the bottom, heated to 700-1,200 deg.C with an electric furnace 7 and allowed to react with the Ru or RuO4 1. The resulting volatile Ru chloride is heated with an electric furnace 7 and allowed to react with the capturing agent 9 during passing through the tube 10 to form water soluble BaRuCl5, etc. This product is treated with water and the Ru or RuO4 is separated and recovered as an aq. soln. of BaRuCl5, etc.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention involves carrying out a chlorination reaction of ruthenium and/or its oxide, and a complex salt-forming reaction of the chloride with a complex salt-forming agent.
The present invention relates to a method for solubilizing ruthenium, which is characterized by producing a soluble ruthenium complex salt.

(Prior art and its problems) Ruthenium has traditionally been used in large quantities as a vapor deposition target for making contact materials such as reed switches, and as a resistor material. It is necessary to collect, purify, and use them effectively.

Generally, ruthenium can be purified by a method that takes advantage of the volatility of its oxide, Rub, after it is first made into a solution.However, due to the nature of ruthenium, it is difficult to make it into a solution. (By the usual method of dissolving using a 10-NaOH mixture, it is difficult to dissolve metallic solids, and it is difficult to dissolve oxides using this method.

Oxide powders and the like are reduced into metallic powders and then dissolved by the above method.

Dissolution methods using alkali molten salts such as KNO and -KOH have also been carried out, but the dissolution rate of metallic solids is slow and is not suitable for industrial use.

(Objective of the Invention) The present invention was made to solve the above problems, and its object is to provide a method for easily and efficiently solubilizing ruthenium and/or its oxide.

(Means for Solving the Problems) In order to solve the above problems, the ruthenium solubilization method of the present invention includes heating ruthenium and/or its oxides while flowing chlorine gas. is converted into chloride and volatilized, and the volatile product is passed through a chloride complex salt forming agent layer to form a soluble ruthenium chloride complex salt through a complex salt forming reaction between ruthenium chloride and the complex salt forming agent. It is.

The heating temperature at this time is preferably 700 to 1200°C.

FIG. 1 shows the relationship between the amount of chloride volatilization of ruthenium and its oxides and temperature. As shown in the figure, the chlorination reaction of ruthenium occurs below 700°C, but sufficient vapor pressure for volatilization cannot be obtained.

Further, there is a peak in the amount of volatilization at 850 to 950°C, and the higher the temperature, the lower the efficiency is. At 1200°C or higher, not only the amount of volatilization decreases, but also energy is required for heating, which is not efficient.

The same applies to oxides, and in the case of oxides, 800
Requires temperature above ℃. Suitable chloride scavengers are:

B a Cj22 K(I aCjI Ca C12 M g C12 rc12 (Example 1) Examples and conventional examples of the ruthenium solubilization method of the present invention will be described.

First, an example of the ruthenium solubilization method of the present invention will be described. 113.62 g of ruthenium buttons (24 buttons) 1 for vapor deposition were set in a reaction tube (inner tube) 2 as shown in FIG.

In the reaction tube (inner tube) 2, there is a silica sand 5 for heating chlorine gas.
The mechanism has a porous ceramic 4 and a ceramic filter 3 above it for gas dispersion. Thereafter, a reaction tube (outer tube) 10 was loaded.

The reaction tube (outer tube) 10 has a scavenger layer on the top, and BaCj! 2 was filled. Electric furnace (A) 7 by 9
While heating to 00° C., chlorine gas was flowed through the chlorine gas blowing pipe 6 at a rate of 10 1/min to carry out a chlorination reaction.

The reaction gas was passed through a 13 a C12 layer packed in a collector 9 heated to 830° C. in an electric furnace (B) 8 to collect ruthenium chloride.

After this reaction was carried out for 4 hours and 30 minutes, Ba (1!2) filled in the scavenger layer was taken out and melted with ice, resulting in an aqueous solution (of BaRuCj!s) without any precipitate.

(Example 2) 180 g of ruthenium oxide 11 powder for resistance paste was compression molded and set in a reaction tube 12 as shown in FIG.

Further, the collecting agent 13 was filled with K(l).

While heating the ruthenium oxide to 1000°C in the electric furnace (A) 14, chlorine gas is supplied at 2f/2f/2 from the chlorine gas blowing pipe 15.
The chlorination reaction was carried out at a flow rate of min.

The reaction gas was passed through a KCl layer filled in a collector 13 heated to 750° C. in an electric furnace (B) 16 to collect ruthenium chloride.

After carrying out this reaction for 7 hours, the KCl packed in the scavenger layer
When I took it out and dissolved it in water, there was no precipitate (K
It became an aqueous solution of JuCβ.

(Conventional example) Ruthenium button 151g1O NaCl0:Na0
The mixture was placed in a solution 51 of H=8:1 and heated to 60° C., and dissolved while stirring.

When this continued for 10 hours, the amount of dissolved ruthenium was 2
It was 8.30 g.

(Effects of the Invention) As can be seen from the above explanation, the method of the present invention has the excellent effect of being able to solubilize ruthenium efficiently, easily, and in a short time.

[Brief explanation of the drawing]

Figure 1 is a graph showing the relationship between the amount of ruthenium chloride volatilization and temperature, Figure 2 is a diagram showing an example of the ruthenium solubilization method of the present invention, and Figure 3 is the ruthenium solubilization method of the present invention. It is a figure showing other examples of.

Claims (1)

[Claims] 1. Ruthenium and/or its oxide 700-12
Ruthenium and/or its oxides are converted into chlorides and volatilized by flowing chlorine gas while heating to 00°C, and the volatiles are passed through a chloride complex salt forming agent layer to form a complex salt of ruthenium chloride and chloride. A method for solubilizing ruthenium, which comprises producing a soluble ruthenium chloride complex salt through a complex salt-forming reaction with a forming agent.