Abstract:

Uniform particles of copper(Ⅱ) a11d chromium (Ⅵ) compounds were prepared by homogeneous precipitation from copper nitrate and ammonium dichromate solutions in the presence of urea. The effects of various experimental parameters on the composition, morphology, and size of the resulting particles were studied. The concentrations of metal salts varied over the raug2.0×10-4-3.2×10-3 mol•dm-3, with ratio [Cu(NO3)2]/[(NH4)2Cr2O7] = 2, and with the urea concentration 0.1-1.25 mol•dm-3. The aging was carried out at 78℃ over a period up to several hours. Thus, copper nitrate and ammonium dichromate solutions yielded spherical thorny particles which had the composition of hydrated copper chromate. Calcination of the particles at 400 ℃ produced CuCrO4, the particle morphology of which was retained.

Key words: Copper(II) and chromium(VI) compounds, Particle morphology, Spherical thorny particles