Abstract
An investigation was made to develop a simple, rapid and accurate determination of zinc in ore by use of EDTA titration with X. O. (xylenol orange) as an indicator. In the method, copper was masked by the addition of thiosulphate without separation. Lead was separated by precipitation with sulphuric acid. Iron, aluminium, manganese and bismuth were precipitated by ammonia, ammonium chloride and ammonium persulphate. Cadmium, if present, had to be separated by hydrogen sulphide. Calcium, magnesium, arsenic and antimony did not interfere. The solution containing zinc was adjusted to pH about 5 using a buffer solution and titrated by EDTA at room temperature. The end point was a sharp change of the coloration from pink to pure yellow. The determination of zinc in various ores by the method gave satisfactory results both in accuracy and precision.
The time required for the analysis was about 4 hours, so that this method was considered to be well suited for routine works.
