JPS6360237A - Reducing and refining method for metal oxide - Google Patents

Abstract

PURPOSE:To easily reduce and refine metal oxides, by impregnating metal oxides with acetic acid in which saccharides are dissolved, by subjecting the above to heat treatment for reduction and then to pulverization, by mixing the resulting powder with inorganic reducing agents, etc., by allowing the resulting mixture to react by the addition of sulfuric acid, and then by applying heat treatment to the above. CONSTITUTION:Saccharides such as cane sugar, etc., are added to acetic acid to undergo dissolution. Single or plural metal oxides are impregnated with the resulting dissolved substance, which is subjected to heat treatment to about 500-800 deg.C. The above heat treatment is continued until generation of decomposition gas is stopped, so that above-mentioned metal oxides are reduced into metals or alloys. Subsequently, the above reduced metals or alloys are pulverized into powder. The above metal or alloy powder is mixed with reducing agents such as borax, acetic soda, etc., and the resulting mixture is allowed to react by the addition of sulfuric acid. Thereafter, the powdered metals or alloys are heated slowly to undergo drying and solidification and further heated to about 900-1,200 deg.C to undergo melting, so that products can be completely refined.

Description

[Detailed Description of the Invention] The present invention is rare gold! f4 oxide
This invention relates to a method of directly reducing and refining metals using i-oxides as raw materials.

The applicant proposes a method in which a metal oxide is impregnated in a reducing organic solvent, heated, and directly refined as a metal, that is, as described below, a raw material mixture is prepared using acetic acid, which is a mixture of gold M oxide and sugar added, as a solvent. Heat treatment is performed to separate and reduce gold H4 from the raw material mixture. We can provide a method of finely pulverizing this reduced metal, mixing it with an inorganic reducing substance, adding sulfuric acid, reacting it, and performing heat treatment to refine it. Acetic acid is originally a reducing solvent and is adsorbed to oxides. It has the characteristic of being easy to use. In particular, a substance prepared by dissolving sugars in acetic acid has an extremely strong reducing power against metal oxides, and it does not require the high temperature heat treatment that is used to simply reduce carbon or hydrogen. It has characteristics comparable to magnesium or calcium reduction. however.

Since reduction cannot be achieved with just acetic acid, sugars are added to increase the reducing power of acetic acid.

The sugar added to acetic acid dissolves in acetic acid as hydrated carbon, and the carbon molecules have the following composition.

Sucrose C,, H1,0, (OH), →C+t + (Ha
O).

Glucose C, H,, O, → C,, + (H, 0) 11 The reducing power of acetic acid increases or decreases depending on the amount of dissolved carbon, that is, the amount of sugar added. Here, the complete relationship between sugar and reduction using several types of oxides is as follows.

(Data) (Concentration of sucrose required for reduction W/CH)
M-0! (Molybdic anhydride/molybdenum trioxide) 4
．． 0WO, (tungstic anhydride/tungsten trioxide)4. IT atOs (tantalum pentoxide) 6.3Zr
Ot (diA/=y nium oxide)8. OB, O, (anhydrous fluoric acid/boron oxide) 9.0 reduction method is glacial acetic acid (C
H, COOH・Pure acetic acid 96% or more ◆Melting point 16.68℃・
Sucrose is dissolved at a boiling point of 118° C. and a specific gravity of 1.057), and the oxide is immersed in this solution, followed by heat treatment. Heat treatment begins with body heat, and as the surface gradually dries out, the surface is sealed with granular or powdered carbon to maintain a reducing atmosphere, and the temperature is further raised to approximately 500°C to 800°C to generate decomposition gas. It is reduced to metal by heating until it stops. The required time for this Fyr is approximately 80 minutes.

Excessive administration of acetic acid during oxide reduction does not affect the degree of reduction, but if the purity used is less than glacial acetic acid, the degree of reduction becomes poor. In addition, if sugar addition is excessive, it is expected that carbon will remain, but even if a shield with carbon equivalent to the total oxygen equivalent of the oxide is provided, it will vaporize as a dissolved substance with acetic acid and there will be no free carbon. Decoy acetic acid is also a buffering agent.

However, the amount of sugar actually required is less than the theoretical equivalent of 175, so there is no concern about carbon remaining in the reducing substance.

Most of the materials mentioned above are mixed with acetic acid and reduced as they are without being dissolved; however, if the reduction is carried out by mixing one or more kinds of materials, and other kinds or a number of materials other than one kind are reduced. When dissolved in vinegar, the product is an alloy.9. Things that have an indispensable relationship with the alloy become mutual compounds and reduce. This alloy formation is a characteristic of acetic acid reduction and is extended to nonmetals by sugar addition adjustment.

Metal or alloy 110 obtained by reducing a metal oxide as described above
Finely pulverized powder to 0 mesh to 200 mesh is mixed with borax or sodium acetate at a ratio of 1:1 to total powdered gold Ml.
5 to 1:0.5 of the total weight of this mixture.
Add sulfuric acid of about 1/100 to 10/100 and allow to react for about 300 minutes. When the reaction has stopped, heat treatment is performed.

Initially, body heat is applied for about 30 minutes within 100°C, and when the surface gradually dries out, the surface is sealed with granular carbon to maintain a reducing atmosphere and the temperature is raised directly. fil? The temperature given varies depending on the metal being forged, but
90 minutes to 12 minutes in the range of 00℃ to 1200℃
After the powdered metal or alloy is melted by continuous heating for 0 minutes, it is thoroughly refined.

After reducing the metal oxide, the powdered metal is pulverized as described above and made into a fine powder using a viscous organic solvent (for example).

A paste-like hydrate of gum arabic, a hydrate of glue or gelate) is mixed and stirred, applied to the surface of a metal that can withstand the heat treatment temperature described below to form a thin film, and this is embedded in carbon powder. Heat treatment at approximately 900℃ to 1100℃ for 90
Powdered metal can be heated at the melting stage by heating for 120 minutes, by directly embedding it in finely powdered metal, or by heat treating by selecting one of the methods depending on the material and shape. IT conversion is carried out to the surface of the metal and about 3 mm below the surface. If the reduced alloy prepared here uses zirconium oxide and boric acid as raw materials, it is natural that Zr-B (
zirconium boron) alloy and heat treated ki4
The surface and subsurface are hardened by substitution precipitation of Zr-B alloy.

(Example 1) 100 grams of tungstic anhydride is mixed with 53 durams of boric acid. Add and dissolve 13 grams of sucrose in 310 grams of glacial acetic acid. This was added, stirred, and left for about 120 minutes to allow sufficient impregnation, and then kept at an annealing temperature of about 100° C. for about 20 minutes to dry the surface. Next, the temperature is raised to around 800°C to generate decomposed gas, and after death, the completion of gas generation is confirmed, heating is stopped, and the animal is gradually cooled. The product is 96 grams of tungsten boride (WB). Total heating time is 90 minutes. A quartz tube was used as the container. The heat source is city gas and the appliance used for the heat source is a city gas burner.

(Example 2) 170 grams of boric acid is mixed with 80 grams of d-zirconium. Add 20 grams of sucrose to 400 grams of glacial acetic acid and dissolve. This was added to the oxide and stirred for about 1 hour (6
0 minutes) After leaving it for sufficient impregnation, heat it at a temperature of approximately 100°C.
Let the surface dry for 5 minutes, then raise the temperature to around 1000℃ for 80 minutes until the end of decomposition gas generation is confirmed. The surface is sealed with granular carbon to maintain the I atmosphere.
Stop the heat source and cool slowly. The product is 160 grams of zirconium boron (Zr-B). Total heating time 95
minutes. The container used is an iron crucible. The heat source is propane gas.
The equipment used as a heat source was a propane gas burner.

(Example 3) The zirconium boron produced according to Example 2 was ground into about 200 meshes using a ball mill.

5 grams of gum arabic is dissolved in 500 cc of water, and 100 grams of zirconium boron powder is mixed and stirred into this aqueous solution.

Using this mixed solvent, mold steel pieces (material 5K-8KS)
-8KD, etc.) A homogeneous coating film is made on the surface and dried. Fill a graphite crucible with carbon powder, embed the prepared steel pieces, and heat to approximately 1100°C for 90 minutes.

Stop heating and slowly cool. The degree of hardening of the steel surface is based on the test results obtained using the Vickers hardness tester at the Chiba Prefecture Machinery and Metals Research Institute in the attached table.

(Example 4) 13 grams of sucrose was dissolved in 310 grams of glacial acetic acid, 150 grams of titanium dioxide was added thereto, mixed and stirred, and left for about 120 minutes to allow sufficient impregnation. Next, heat the mixture at a temperature of 1o for about 20 minutes.
Dry the surface at 0°C. Further, the heating temperature is increased to around 800° C., and after confirming that generation of decomposed gas has stopped, the heat source is stopped and cooling is performed gradually. Reduced nine titanium (TI)! i is 9
It is 8 grams. This was ground into powder using a ball mill into 200 mesh pieces. After mixing 98 grams of powdered titanium with 90 grams of sodium acetate, 10 grams of titanium was added to react, and the mixture was allowed to stand for about 300 minutes, and once the heat of reaction had stopped, heat treatment was performed again.

First, the reaction material in the container, which is about to thermally expand within 50 to 100 degrees Celsius, is suppressed by temperature control and gradually dried. In order to maintain a return deposit atmosphere, the surface is sealed with granular carbon, and the temperature is further increased to around t-1000°C, heated for 120 minutes, and then the heat source is stopped and slowly cooled. Powdered titanium is completely refined into metallic titanium using a melter.

Excluding the amount of N scattered into the crucible, the product weight is 84 grams.

The container used is a graphite crucible, the heat source is propane gas, and the equipment used is a propane burner.

As explained above, in this method, one or a few oxides are brought into contact with acetic acid in which sugar has been added and dissolved, the surface is heated and dried, and the temperature is maintained at 500°C or higher to generate decomposed gas. is released and reduced to produce a powdered metal or alloy.

This powdered reduced metal is mixed with a viscous organic solvent to produce other gold M4.
A collapsed surface is created on the surface, and the coated surface is melted and replaced by heat treatment.

Furthermore, the above-mentioned method is characterized in that an inorganic reducing substance is blended into the powdered metal or alloy, borosemic acid is added thereto, the reaction is performed, and the metal is melted by heat treatment to directly refine the metal.

Claims (3)

[Claims] (1) We discovered that a substance prepared by adding sugars to acetic acid and dissolving it in various organic solvents has a strong reducing power. Next, single or multiple metal oxides are impregnated into this dissolved substance, and by subjecting it to heat treatment, the dissolved mixed substance is separated and reduced to become a metal or an alloy. Furthermore, this reduced metal or alloy is finely pulverized into a powder, mixed with a reducing agent such as borax or sodium acetate, and then sulfuric acid is added to cause a reaction. Heat treatment is performed to melt the powdered metal or alloy and produce a product. A method for reducing and refining metal oxides, characterized by complete refining. (2) A single metal oxide or a mixture of multiple metal oxides is impregnated into a substance prepared by dissolving sucrose in pure acetic acid, and then heat treated to reduce the metal or alloy substance to a finely ground powder, which is then mixed with a viscous organic solvent. mixed and stirred to form a coating film on the surface of the metal material or metal processing material, and heat-treated by immersing the material in powdered carbon, or directly immersing it in finely ground powder, Choose one method. 2. A method according to claim 1, characterized in that the powdered metal or alloy is displaced and expanded on the surface and subsurface of the metal material or metal processing material during the melting stage. (3) A raw material mixture of zirconium oxide and boric acid is immersed in a solution of glacial acetic acid and sucrose, and then heat treated to dry and reduce. Next, this is made into a finely ground powder, mixed with a viscous organic solvent, applied to the surface of metal materials or metal processing materials, etc. to create a film, and then embedded in carbon powder such as charcoal powder or granular carbon and heat treated. 3. The method according to claim 2, wherein the surface and subsurface of the material are hardened by displacement precipitation of a zirconium boron alloy.