Selective dissolution of lead from sulphur cpds. - by contacting within aq. soln. contg. a chloride (SW 7.11.77)

摘要

A PbCl2 soln. free from Cu is obtd. from S cpds. contg. Pb by contacting the cpd. with an aq. soln. contg. =1 chloride of Cu, Bi, Sb or Ag. The amt. of chloride is less than or equal to that which is stoichiometrically necessary for complete dissolution of the Pb in the cpd. Pref. the temp. of the aq. soln. is between 60 degrees C and the b.pt. of the reaction mixt. The aq. soln. contains =4 g. equiv. of Cl ions/l. The Cl ions are introduced by adding a chloride of NH4, an alkali metal or an alkaline earth metal. The pH is 0-3. Selective dissolution of Pb from S cpds. contg. Pb is possible. Galena mixed with other S cpds. e.g. Zn blend, Fe pyrites can be treated.