INDUSTRIAL precipitation of cUPRIC HydroxY-salts

Andrej Lubej,a Tine Koloini,b and Ciril Poharb
a Cinkarna Celje, Metallurgical and Chemical Company, Kidričeva 26, SI-3000 Celje, Slovenia,
b Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5 SI-1000 Ljubljana, Slovenia

The reaction between Cu2Cl(OH)3 and slaked lime suspension was studied. It was found that the concentrations of the participating ions in the reaction mixture determined which of the possible products CuO, or CaCu3Cl2(OH)6, or CaCu4Cl2(OH)8 was precipitated. The reaction conditions also influenced the repose times of the precipitates. The considerably longer repose time of CuO than that of the MB4 enables industrial production of the MB4 of the prescribed purity. When co-precipitation of MB4 and CuO occurs, it causes blackening of the product. From the composition and the concentrations of all the ionic species present in equilibrium with the solid phase, the solubility products of the precipitated compounds were estimated.

Key words: Copper fungicides, copper oxide, calcium tri-copper di-chloride hexa-hydroxide, calcium tetra-copper di-chloride octa-hydroxide, solubility constant, industrial precipitation.