Stabilizing method for mercury vapor release from burning amalgam mimicking the practice of artisanal small scale gold mining

A stabilizing method for mercury vapor using compatible pellets containing immobilized-colloidal sulfur has been studied. The pellets were made of sawdust and subsequently coated by chitosan prior to immobilization of colloidal sulfur. The treated pellets were physically stable during rotating in dry conditions and did not decompose during 5 days of immersion either in water, in diluted acetic acid, in methanol or in hexane. The sulfur and water contents of the pellets were 2% and 16.25% respectively. The absorption capacity for mercury vapor released from burning amalgam was 0.12 g of Hg per gram pellets. The 20 gram of treated pellets absorbed and stabilized 93-96 wt% of 1.5 g mercury vapor source. At least 30% of HgS can be desorbed and separated from the pellets by washing it with diluted aqueous acetic acid. (C) 2018 Elsevier B.V. All rights reserved.