UNI 3870-1957 Procedures for chemical analysis of minerals. Determination of the lead, copper and zinc content of iron minerals. Electrolytic and gravimetric method for standard analysis.
From the hydrochloric solution of the sample, after reduction of the arsenic with ferrous chloride and the iron with sodium bisulfite, lead and copper are precipitated at the same time, in an acidic environment by acetic acid. The sulfides obtained are dissolved in nitric acid and lead and copper are simultaneously separated from the solution by electrolysis, when the lead content is less than 1 percent; for higher lead contents, the lead is first separated in the form of sulphate; copper is precipitated in the filtrate in the form of sulphide and, after redissolution, it is determined electrolytically. Finally, in the solution from which lead and copper have been separated, the remaining traces of iron are first precipitated using ammonia; then the zinc is precipitated in the form of sulphide in an acetic environment and, after calcination, it is determined as an oxide. Solutions and reagents. Method. Calculations.
UNI 3870-1957 history
1957UNI 3870-1957 Procedures for chemical analysis of minerals. Determination of the lead, copper and zinc content of iron minerals. Electrolytic and gravimetric method for standard analysis.