Removing mercury ion from aq. solns. - by pptn. with formamidine:sulphinic acid followed by filtration

摘要

A process for removing Hg and Hg salts from aq. liquids by pptn. and filtration, in which formamidinesulphinic acid (I) is added to ppte. ionic Hg. Pref. the (I) is added in up to 20 times molar excess w.r.t. total Hg present in ionic form in the liq. Pref. filtration is carried out after addn. of a filter aid, esp. where the filter aid is Fe hydroxide or Fe chloride used in an amt. of up to 5 mmol per litre of the liq. to be purified. The pptn. and filtration can be carried out continuously or discontinuously. USE/ADVANTAGE - Use of (I) gives good removal of ionic Hg from aq. solns. and the process can be used with Hg-contg. salt sols. from chloralkali electrolysis which also contain high concns. of chlorate and chlorine which have an oxidising effect but do not interfere with the action of the (I).