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Ion flotation of dichromate with a cationic surfactant
Author(s) -
Grieves Robert B.,
Wilson Thomas E.,
Shih Kenneth Y.
Publication year - 1965
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690110515
Subject(s) - pulmonary surfactant , potassium dichromate , chemistry , aqueous solution , cationic polymerization , chromium , bromide , inorganic chemistry , adsorption , nuclear chemistry , organic chemistry , biochemistry
An experimental investigation is presented of the flotation of dichromate ion from aqueous solution with a cationic surfactant, ethylheaxadecyldimethylammonium (EHDA) bromide. Dichromate forms a colloidal complex with EHDA ion in a molar ratio of approximately 1 : 2. Excess surfactant causes the formation of a stable foam to which the complex is adsorbed, providing the separation of dichromate from aqueous solution. Batch flotation studies were conducted utilizing approximately 2‐liter solutions containing from 10 to 200 mg. of dichromate ion (4.8 to 96.3 mg. of hevavalent chromium), with masses of EHDA‐Br ranging from 400 to 800 mg. The effects of mass of surfactant added, dichromate concentration, p H, and possible interfering anions were determined. A comparison is made with pure surfactant solutions, and the mechanism of the process is discussed. Most efficient operation is achieved with a molar feed ration of EHDA ion to dichromate ion from 2.1 to 3.0, and removal ratios ranging from 80 to 95% are obtained. Reduction of the residual dichromate below 10% of the feed concentration requires additional surfactant and produces excessive foam, which could be overcome by modifications in operating conditions.