Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB39542/59A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Asahi Kasei Corp
Asahi Chemical Industry Co Ltd
Original Assignee
Asahi Chemical Industry Co Ltd
Asahi Kasei Kogyo KK
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Filing date
Publication date
Application filed by Asahi Chemical Industry Co Ltd, Asahi Kasei Kogyo KKfiledCriticalAsahi Chemical Industry Co Ltd
Publication of GB894085ApublicationCriticalpatent/GB894085A/en
C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
C01B19/00—Selenium; Tellurium; Compounds thereof
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Chemical & Material Sciences
(AREA)
Organic Chemistry
(AREA)
Inorganic Chemistry
(AREA)
Organic Low-Molecular-Weight Compounds And Preparation Thereof
(AREA)
Catalysts
(AREA)
Abstract
Selenium values are recovered from unsaturated aldehydes produced by the oxidation of unsaturated hydrocarbons in the presence of selenium or selenium dioxide as catalyst, or from the unsaturated nitriles produced from the aldehydes by reaction with ammonia, by spraying with water having a pH of 7-9 and a temperature below 50 DEG C. separating sprayed water containing selenium values from the treated gas, and separating the selenium values from the water. The sprayed water may be recycled one or more times. The finally separated sprayed water may be treated with hydrochloric, nitric, or sulphuric acid so as to produce an acid concentration of 2-12%, and the temperature maintained at 40 DEG -80 DEG C. with aeration so as to precipitate elementary selenium.
GB39542/59A1959-09-041959-11-20A method for the recovery of selenium
ExpiredGB894085A
(en)
Process for the manufacture of melamine by means of catalytic conversion of carbamide in the presence of gaseous nh3 or an nh3containing gaseous mixture