FIELD: chemistry of organophosphorus compounds, chemical technology. SUBSTANCE: invention relates to a method for preparing bis-[(1-hydroxyethane-1,1-diphosphonato(2-)] ammonium cuprate (II) dihydrate that involves the following procedures: bis-[(1-hydroxyethane-1,1-diphosphonato(2-)] ] ammonium cuprate (II) is prepared by crystallization from a solution prepared by mixing printed board depleted itching solution containing copper (II) and ammonia or ammonium salts and 1-hydroxyethane-1,1-diphosphonic acid taken in the amount providing the mole ratio copper (II) : 1-hydroxyethane-1,1-diphosphonic acid = 1.0:(2.0-4.0) with pH value about 2.0-3.5. Product prepared by this method can be used for antibacterial treatment of water, for protection of equipment against corrosion in petroleum extracting, petroleum processing, paper and pulp industry as a fungicide and copper microfertilizer in agriculture, for preparing electrolytes for galvanic copper plating, for preparing other copper chelates. Invention provides reducing cost of bis-[(1-hydroxyethane-1,1-diphosphonato(2-)] ammonium cuprate (II) in retention of its phase homogenous properties and simultaneous utilization of toxic waste in radio-electronic manufacture, i. e. the depleted solution of printed boards. EFFECT: improved preparing method. 10 cl, 1 tbl, 5 ex
