METHOD OF DETERMINING CONTENT OF COPPER AND OXIDES THEREOF IN ULTRAFINE COPPER POWDERS

摘要

FIELD: analytical methods.;SUBSTANCE: invention is directed to determining content of Cu, Cu2O, and CuO in cases of their copresence in ultrafine copper powders used in powder metallurgy for preparing products by caking methods, synthesis of intermetallides, and as components of current lubricating materials and metal-polymers. Method comprises dissolving copper and its oxides and determining content thereof by titration technique. More specifically, sample of ultrafine copper is preliminarily treated for 30-40 min in helium stream at 70-90°C and then evacuated to pressure 10^-4-10^-5 mm Hg for 20-30 min and dissolved in sulfuric acid solution of potassium dichromate, after which excess of potassium dichromate is found via potentiometric titration of Moor salt. Contents of copper and its oxides are then calculated in terms of following equations: m(Cu)=34.270·C₂·V₂-3.396·(C₀·V₀-C₁·V₁)-428.380·M (grams); m(CuO)=M-m(Cu)-m(Cu₂O) (grams), where m represents mass of Cu or Cu₂O, or CuO (grams), M mass of ultrafine copper powder sample (grams), C₀ concentration of initial potassium dichromate solution (N), V₀ volume of initial potassium dichromate solution (mL), C₁ concentration of Moor salt solution (N), V₁ volume of Moor salt solution (mL), C₂ concentration of sodium thiosulafate solution (N), and V₂ volume of sodium thiosulafate solution (mL).;EFFECT: simplified analytical procedure.;2 tbl