High purity manganese and method for producing same

Patent metadata

Field	Value
Publication number	US-9725814-B2
Application number	US-201214365287-A
Country	US
Kind code	B2
Filing date	Jul 18, 2012
Priority date	Jan 10, 2012
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

High purity manganese having a purity of 3N (99.9%) or more, wherein number of non-metal inclusions with a size of 0.5 μm or more is 50000 or less per 1 g of the high purity manganese. A method for producing high purity manganese, wherein refining is performed using a raw material (secondary raw material) obtained by acid-washing a manganese raw material (primary raw material) so that the produced high purity manganese has a purity of 3N (99.9%) or more, and number of non-metal inclusions with a size of 0.5 μm or more is 50000 or less per 1 g of the high purity manganese. The present invention provides a method for producing high purity metal manganese from commercially available manganese, and aims to obtain high purity metal manganese having a low LPC.

First claim

The invention claimed is:

1. A method for producing a high purity manganese, comprising a refining process performed by the steps of:
acid-washing a manganese primary raw material having a purity of 2N or higher to remove contaminants and a layer of oxides from a surface thereof to obtain a secondary raw material;
leaching manganese with an acid from the secondary raw material to produce an acid leachate such that an amount of 1% or more of the secondary raw material remains undissolved within the acid leachate after said leaching step;
performing electrolysis using the acid leachate as an electrolytic solution on a cathode side of the electrolysis to obtain a manganese deposit; and
melting the manganese deposit in an inert atmosphere of a reduced pressure of 0.01 to 750 torr to eliminate impurities as slag and to obtain a cast ingot of high purity manganese having a purity of 3N (99.9%) or higher and containing a dispersion of foreign substances of non-metal inclusions with a size of 0.5 μm or larger in a number of 50000 or less per 1 g of the high purity manganese.

2. The method according to claim 1 , wherein, during said melting step, a deoxidizing agent having a stronger active potency than Mn is added to the manganese deposit and wherein the slag is concentrated on an upper part of the ingot.

3. The method according to claim 2 , wherein the deoxidizing agent is La, Ca or Mg.

4. The method according to claim 1 , further comprising the step of washing the manganese deposit with diluted nitric acid.

5. The method for producing high purity manganese according to claim 1 , wherein the amount of the secondary raw material remaining undissolved in the acid leachate is 1 to 50%.

6. The method according to claim 5 , wherein, during said melting step, a deoxidizing agent having a stronger active potency than Mn is added to the manganese deposit and wherein the slag is concentrated on an upper part of the ingot.

7. The method according to claim 6 , wherein the deoxidizing agent is La, Ca or Mg.

8. The method according to claim 6 , further comprising the step of washing the manganese deposit with diluted nitric acid.

Assignees

• Yagi Kazuto
• Shindo Yuichiro
• Hino Eiji
• Jx Nippon Mining & Metals Corp

Inventors

• Yagi Kazuto
• Shindo Yuichiro
• Hino Eiji

Classifications

• C22C22/00

  Alloys based on manganese · CPC title

• C25C1/10 Primary

  of chromium or manganese · CPC title

• C22B47/00

  Obtaining manganese · CPC title