IP Library Granted Patent US 7,935,328
Granted Patent B2
US 7,935,328 · App. 12/010,377 · Granted May 3, 2011

Method for manufacturing scorodite

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Quick Facts
Patent No.
US 7,935,328
App. No.
12/010,377
Granted
May 3, 2011
Kind
B2
Abstract

The present invention provides a method for manufacturing scorodite in which scorodite may be obtained at high production efficiency and a high As concentration ratio. The present invention provides a method for manufacturing crystalline scorodite from acidic aqueous solution containing pentavalent As and trivalent Fe, the method comprising a step for adding a basic sodium compound to the acidic aqueous solution such that the sodium concentration in the acidic aqueous solution becomes larger than 0 g/L and equal to or less than 4 g/L.

Claims (5)

1. A method for manufacturing crystalline scorodite from acidic aqueous solution containing pentavalent As and trivalent Fe, the method comprising a step for adding a basic sodium compound to the acidic aqueous solution such that the sodium concentration in the acidic aqueous solution becomes larger than 0 g/L and equal to or less than 4 g/L.

2. The method for manufacturing crystalline scorodite claimed in claim 1 wherein said basic sodium compound is at least one compound selected from the group consisting of sodium carbonate, sodium hydroxide, and sodium hydrogen carbonate.

3. The method for manufacturing crystalline scorodite claimed in claim 1 wherein the pH of said acidic aqueous solution is less than 1.0 before the addition of said basic sodium compound and is 1.0 to 1.5 after the addition.

4. The method for manufacturing crystalline scorodite claimed in claim 1 wherein the trivalent Fe is provided as ferric sulfate.

5. The method for manufacturing crystalline scorodite claimed in claim 1 wherein said acidic aqueous solution is sulfuric acid-leached solution from electrolytically precipitated copper.

Assignments (3)
CHANGE OF NAME Recorded Oct 19, 2010
From: NIPPON MINING HOLDINGS, INC.
To: JX NIPPON MINING & METALS CORPORATION
Reel/Frame 025163/0049 →
MERGER Recorded Oct 14, 2010
From: NIPPON MINING & METALS CO., LTD.
To: NIPPON MINING HOLDINGS, INC.
Reel/Frame 025140/0159 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 24, 2008
From: KIMURA, YUKIO; KATSURA, SHIGEO
To: NIPPON MINING & METALS CO., LTD
Reel/Frame 020475/0364 →