Mercury recovery from alkali works effluents by ion - exchange resisn wti thio urea elution

摘要

Method of recovery metallic mercury from mercurous solns. such as waste brine from alkali-chloride electrolysis carried out using an Hg-cathode. The Hg-ions in the waste soln. are first sequestered using a polystyrene divinylbenzene ion exchange resin and then eluted with aqs. thiourea soln. The Hg is then dissociated from the enriched eluant as HgS by the controlled addition of ammonia, sodium carbonate, or hydrogen sulphide, whilst maintaining the pH constant to achieve quantitative desportion by forming a complex. The HgS is then worked up into metallic Hg by thermal treatment in admixture with iron filings.