| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 423087000 | Group VA metal or arsenic (Sb, Bi, or As) | 8 |
| 20080233023 | Method for manufacturing scorodite - 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. | 09-25-2008 |
| 20100196230 | METHOD OF PROCESSING NON-FERROUS SMELTING INTERMEDIATE CONTAINING ARSENIC - Provided is a method of easily producing easily-filterable and stable scorodite that meets the leaching standard (conformance to Japanese Environmental Agency Notice 13) with excellent reproducibility and without using complex operations, when processing arsenic that is included in non-ferrous smelting intermediates, and particularly when processing arsenic in the form of a sulfide. Scorodite is produced by a leaching step of leaching arsenic from a non-ferrous melting intermediate containing arsenic in the weakly acid region, a solution adjusting step of oxidizing trivalent arsenic to pentavalent arsenic by adding an oxidizing agent to the leaching solution, and a crystallizing step of converting the arsenic in the adjusted solution to scorodite crystals. | 08-05-2010 |
| 20100196231 | Method Of Processing Non-Ferrous Smelting Intermediates Containing Arsenic - The object is to remove arsenic in a stable form from an arsenic-containing smelting intermediate product. Thus, disclosed is a method for treating an arsenic-containing nonferrous smelting intermediate product, which comprises: a leaching step of subjecting a mixed slurry of a nonferrous smelting intermediate product containing arsenic in the form of a sulfide and a nonferrous smelting intermediate product containing arsenic and metal copper to the oxidation/leaching in an acidic range to produce a leaching solution; a solution preparation step of adding an oxidizing agent to the leaching solution to oxidize trivalent arsenic into pentavalent arsenic, thereby producing a preparation solution; and a crystallization step of converting arsenic contained in the preparation solution into a scorodite crystal. | 08-05-2010 |
| 20110076208 | Method of Extracting Te and Bismuth Oxide and Recovering Byproducts - A method of extracting Te and bismuth oxide and recovering byproduct comprises: leaching raw materials with a Te content of ≧1.8% by utilizing a leaching system containing H | 03-31-2011 |
| 20120164041 | Stabilization of Arsenic-Containing Wastes Generated During Treatment of Sulfide Ores - A method is provided for the efficient stabilization, removal and disposal of arsenic-containing wastes generated in metal recovery processes that employ roasting techniques and the like. The conversion of the mostly trivalent arsenite compounds in the wastes to mostly pentavalent solid arsenate precipitates is accomplished by mixing the wastes with water and a ground iron-containing mineral, such as goethite, to form an aqueous slurry of wastes and ground iron-containing mineral, acidifying the slurry to a pH of less than about 1.0, treating the acidified slurry with oxygen gas in a pressurized vessel at a temperature higher than about 120° C. and providing an oxidation catalyst comprised of a water-soluble nitrate and a water-soluble iodide. The overall efficiency of the controlling chemical reactions is improved by the addition and use of the catalyst. The resulting solid arsenate precipitates, in the form of scorodite, are ideally suited for safe disposal with minimum or no further treatment. Unconverted soluble trivalent arsenic compounds remaining in solution may be converted and precipitated as additional scorodite by mixing and agitating the slurry with soluble iron salts under controlled conditions. The resulting precipitates meet or exceed environmental requirements for impoundment and safe disposal. | 06-28-2012 |
| 20130272932 | Precipitation of Antimony and Bismuth from Copper Refinery Electrolyte Using PbO2 - The invention is suitable for use in metal and nonmetal mining and in general, in any area of operation containing Sb and Bi in solution in an electrolyte based mainly on sulfuric acid. The system consists in contacting solid lead dioxide (PbO | 10-17-2013 |
| 20140356261 | METHOD FOR ARSENIC OXIDATION AND REMOVAL FROM PROCESS AND WASTE SOLUTIONS - The disclosure relates to the oxidation and immobilization of trivalent arsenic from arsenic-containing solutions. The process includes oxidation of trivalent arsenic (As | 12-04-2014 |
| 20180023165 | METHOD FOR VITRIFICATION OF ARSENIC AND ANTIMONY | 01-25-2018 |
