title: The use of a rotating cylinder electrode to recover zinc from rinse water generated by the electroplating industry.
abstract: This work concerns the application of a laboratory scale rotating cylinder electrode (RCE) to recover zinc from rinse water generated by the electrolytic zinc process (initially 1,300, 4,400, 50, 20 mg L(-1) of Zn(II), Fe(III), Ag(I) and Cr(VI), respectively, at pH 2), although it is also applicable to other electroplating industries. Experimental results demonstrated the convenience of the removal of ferric ions, as (Fe(OH)(3(s))) by a pH adjustment to 4, before zinc electro recovery on the RCE. The generation of smooth zinc deposits on the RCE was obtained at Reynolds numbers within the range of 15,000 ≤ Re ≤ 124,000 and limiting current densities (J(L)) in the interval of -4.8 to -13 mA cm(-2). The zinc recovery reached a conversion of 67% in 90 min of electrolysis for Re = 124,000 and J = -13 mA cm(-2), 21% current efficiency, and energy consumption of 9.5 kWh m(-3). The treated solution can be recycled back through the same rinsing process.
authors.affiliation: Universidad Nacional Autónoma de México, México.
authors.forename: Sairi
authors.initials: S
authors.lastname: Matlalcuatzi
authors.forename: José L
authors.initials: JL
authors.lastname: Nava
mesh_terms: D011232:Chemical Precipitation; D004566:Electrodes; D004595:Electroplating; D007220:Industrial Waste; D007501:Iron / Q000737:chemistry; D015032:Zinc / Q000302:isolation & purification*
chemical_list: D007220:Industrial Waste; D007501:Iron; D015032:Zinc