Investigation of zinc dissolution and cadmium precipitation rates in a Cd2+/Zn cementation system

Halikia, I; Voudouris, N

dc.contributor.author	Halikia, I	en
dc.contributor.author	Voudouris, N	en
dc.date.accessioned	2014-03-01T01:54:27Z
dc.date.available	2014-03-01T01:54:27Z
dc.date.issued	2005	en
dc.identifier.issn	03719553	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/27391
dc.subject	Cadmium precipitation	en
dc.subject	Cd2+/Zn cementation	en
dc.subject	Zinc dissolution	en
dc.subject.other	Cadmium	en
dc.subject.other	Correlation methods	en
dc.subject.other	Dissolution	en
dc.subject.other	Precipitation (chemical)	en
dc.subject.other	Zinc	en
dc.subject.other	Zinc metallography	en
dc.subject.other	Cadmium precipitation	en
dc.subject.other	Cd2+/Zn cementation	en
dc.subject.other	Mass balances	en
dc.subject.other	Zinc dissolution	en
dc.subject.other	Cadmium metallurgy	en
dc.title	Investigation of zinc dissolution and cadmium precipitation rates in a Cd2+/Zn cementation system	en
heal.type	journalArticle	en
heal.identifier.primary	10.1179/037195505X49732	en
heal.identifier.secondary	http://dx.doi.org/10.1179/037195505X49732	en
heal.publicationDate	2005	en
heal.abstract	In this paper, an investigation of the Cd2-/Zn cementation system is attempted through a semi-theoretical approach, correlating the rates of zinc dissolution and cadmium precipitation under various conditions. Two series of experiments were carried out using zinc in the form of sticks and dust, respectively, while cadmium ions were dissolved as sulphates. The parameters examined were temperature (25-50°C), additives (H 2SO4, NH4OH, Na2SO4), stirring speed (200-600 rpm), initial Cd2+ concentration and granulometric size of zinc dust (0-78-1-84 mm). In the second group of tests, continuous recording of pH change versus time was carried out. Total dissolved solids curves versus pH were constructed for each experiment showing solid cadmium to be the only precipitated phase, and mass balances for the two elements were evaluated for all tests. To account for the sampling position in the reactor, a new concept, the normalisation coefficient, is introduced and evaluated, correlating the species' concentrations in the system. Also time expansion was taken into account and equilibrium constants were evaluated. Based on the above, a correlation equation between the rates of zinc dissolution and cadmium precipitation is derived theoretically and it is confirmed by the experimental results. This analysis demonstrated the important role of pH for the system kinetics and the considerable effect obtained using normalisation coefficient on the experimental data. The plots of the normalised Cd2+ concentrations in the solution versus Zn2+ dissolved, verify the proposed linear dependence between the rates of cadmium precipitation and zinc dissolution. © 2005 Institute of Materials, Minerals and Mining and Australasian Institute of Mining and Metallurgy.	en
heal.journalName	Transactions of the Institutions of Mining and Metallurgy, Section C: Mineral Processing and Extractive Metallurgy	en
dc.identifier.doi	10.1179/037195505X49732	en
dc.identifier.volume	114	en
dc.identifier.issue	2	en
dc.identifier.spage	95	en
dc.identifier.epage	108	en