%0 Journal Article
%T Mechanism of Extraction of Oxalic Acid by Quaternary Ammonium Salt<br>季铵盐萃取草酸的机理
%A TANG Hong-ping
%A YANG Ming-de
%A HE Pei-jiong
%A <br>唐红萍，杨明德，何培炯
%J 过程工程学报
%D 2002
%I 
%X Quaternary ammonium salt (N263) has strong affinity with Au(CN)2 in cyanide solutions, but Au is not readily stripped. Stripping by acidic thiourea solutions with air sparging shows good promise, and the stripping efficiency is improved significantly by addition of oxalic acid in the stripping solution. It is found that oxalic acid is extracted into the organic phase during stripping. In this paper, the mechanism of extraction of oxalic acid is studied by 3 models of extraction equilibrium and infrared spectrum. It is shown that oxalic acid is extracted mainly as neutral molecule (ratio to N263 is 1:1), which is associated with the anions of quaternary ammonium salts by hydrogen bond. There are still small quantities of oxalic acid anions H3C4O8 which exchange with Cl of N263 to form 1:2 ionic pairs with the cations of N263.
%K quaternary ammonium salt
%K oxalic acid
%K hydrogen bond
%K solvent extraction
%K mechanism<br>季铵盐
%K 草酸
%K 中性缔合
%K 溶剂萃取
%K 金矿石
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=5B3AB970F71A803DEACDC0559115BFCF0A068CD97DD29835&cid=3FCF8B1A330466D5&jid=B9EE12934D19905403D996AE65CEEEED&aid=0D54765487999BF3&yid=C3ACC247184A22C1&vid=0B39A22176CE99FB&iid=B31275AF3241DB2D&sid=60E9AACF61B3107F&eid=B99A53AADE50D922&journal_id=1009-606X&journal_name=过程工程学报&referenced_num=1&reference_num=11