METHOD OF TREATING SLAG CONTAINING CHROMIUM OXIDE

• Main Authors: YUKI TOSHITAKA, IKEZAKI EIJI, YANAGI MASATO
• Format: Patent
• Language: English
• Published: 28.07.2005
• Edition: 7
• Subjects: BLASTING; CHEMISTRY; DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS,IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KINDOF FURNACE; DISPOSAL OF SOLID WASTE; FURNACES; HEATING; KILNS; LIGHTING; MECHANICAL ENGINEERING; METALLURGY; METALLURGY OF IRON; OVENS; PERFORMING OPERATIONS; PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OFWROUGHT-IRON OR STEEL; RECLAMATION OF CONTAMINED SOIL SOIL; RETORTS; TRANSPORTING; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS; TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE; WEAPONS

PROBLEM TO BE SOLVED: To provide a method of treating slag containing a chromium oxide for easily treating hexavalent chromium in the slag containing the chromium oxide while preventing the generation of drain containing hydrogen sulfide or sulfur. SOLUTION: The slag containing the chromium oxide is dipped in warm water, and hexavalent chromium in the slag containing the chromium oxide is eluted into the warm water and eliminated from the slag containing the chromium oxide. The temperature of the warm water is 30-100°C, and the slag containing the chromium oxide is dipped in a treatment vessel 15 at a ratio V/W of the volume V of warm water to the weight W of the slag containing the chromium oxide being 0.25 or more. A dipping time T is at least 30 minutes. Further, it is preferable that the layer of the slag containing the chromium oxide put in the treatment vessel 15 is rolled within the dipping time T at least the number of times N computed by N=INT[0.25T/(30V/W)]. INT shows arithmetic processing for obtaining an integer value by omitting fractions to a decimal point of 0.25T/(30V/W). COPYRIGHT: (C)2005,JPO&NCIPI