The invention discloses a method for preparing fine
copper powder by suspension reduction
roasting of
alkaline etching waste liquid, which comprises the following steps: firstly, adding
magnesium chloride into the
alkaline etching waste liquid, adjusting the pH value of the solution, forming
magnesium hydroxide precipitate and adsorbing
impurity metal; then, under a dispersing agent or an ultrasonic
system, three-phase separation of
copper,
ammonia and
chlorine of the
alkaline etching waste liquid is achieved through an alkalization reaction, and particle size control can be conducted on
copper oxide. And then carrying out suspension reduction
roasting on the fine
copper oxide powder by taking
ammonia-containing gas recovered by an alkalization method as carrier gas flow and a
reducing agent to finally prepare the fine copper
powder. According to the method, an alkalization method and suspension
roasting are combined, a new path for clean and efficient
recovery of copper in the alkaline
etching waste liquid through a pyrogenic process is opened up, and the superfine copper powder with the average particle size smaller than 10 microns is prepared by optimizing alkalization reaction and roasting conditions. Compared with the prior art, the preparation period is short, the
resource utilization rate is high, the process is safe and
environmentally friendly, and the problem of large-scale production of the fine copper powder is expected to be solved.