Verfahren zur Herstellung von Silberpulver

摘要

Powdered silver is produced by reacting an aqueous solution of silver nitrate with an alkali hydroxide to form a precipitate of silver oxide and reducing an aqueous suspension of the precipitate by formaldehyde in the presence of a water soluble colloid e.g. gum arabic. The reduction may be effected in two stages (i) at a temperature of 20-40 DEG C. to form silver formate and (ii) at a temperature of 40-70 DEG C. to dissociate the silver formate and produce silver. Alternatively, the silver nitrate may be dissolved in water in the presence of formaldehyde and gum arabic and sodium or potassium hydroxide added at a temperature of 50-70 DEG C.