method of coprecipitation malachite and method for preparing a bismuth complex of copper acetylure from coprecipite, and complex product

摘要

1501459 Basic copper carbonate EI DU PONT DE NEMOURS & CO 25 Feb 1975 [25 Feb 1974] 7877/75 Heading C1A [Also in Divisions Bl and C2] Agglomerates of crystalline particles of basic copper carbonate having uniformly dispersed therein bismuth in amounts in the range of 1-5% by weight based on the amount of copper present are prepared by a process comprising the following steps: precipitating hydrated copper carbonate particles by the simultaneous addition to water of solutions of cupric salts and alkali metal carbonate or bicarbonate to form a reaction mixture, said solutions being in such proportions as to maintain the pH in the range of 5À0 to 8À0, nucleating and converting the hydrated copper carbonate to basic copper carbonate in the reaction mixture at a temperature of at least 60‹ C., and growing agglomerates of the nucleated crystalline particles by precipitating basic copper carbonate containing bismuth by the addition to the reaction mixture of solutions of cupric salts, bismuth salts and alkali metal carbonate or bicarbonate in such proportions as to maintain the pH in the range 5À0 to 8À0 with the reaction mixture at a temperature of at least 60‹ C. until the average cross-sectional dimension of the agglomerate of crystallites is at least 10 microns. A particulate cuprous acetylide complex having the general formula wherein w=4, x = 0À24-4À0, y=0À24-2À40 and z = 0À67-2À80 and the Bi is present in an amount of 2-5% by weight based on the amount of copper present, and having a total surface area of at least 5 m.SP2/SP/g. and average particle size of at least 10 Á is produced by subjecting the basic carbonate as a slurry in aqueous medium at 50-120‹ C. to the simultaneous action of formaldehyde and acetylene at a partial pressure of not more than 2 atmospheres, the aqueous medium having a pH of 3-10 at the start of the reaction.