Preparation of sulfur of high purity

Abstract

A mc thod is described for producing sulfur thaL conLains Ie. Lhan 1.3 X lO-5 m ole [racLion of li q uid-solu ble, solid-insolubl e impuriLies as dcLermin ed by Lh e fr'e ezing point depression. This co rr e ponds t.o a purity of 99.999 mole p ercen t. Man y of Lhe impurities, including organic maLLcl', a r(' re moved by o,(ldaLion with s ulfuric and nitric ac ids. The nonvo lati le impuri ties are r e movcd on disLi lhng the s ulfur. The r esidual s ulfuric acid IS r e moved by a s pecia l exLractIO n wi th dist illed wat er. Methods a rc described [or deter mining sm a ll a mounLs of Lhe foll owing impurities : Se lrn ium , tellurium, arsen ic, iron, carbo n, SlIlful'i c acid, and residuc after ignition .