The invention discloses a green method for preparing battery grade
nickel sulfate from
nickel salt. The green method for preparing battery grade
nickel sulfate from the
nickel salt comprises the stepsthat the
nickel salt and
ammonium salt are mixed,
ammonia water is added,
ammonia leaching reaction is carried out, a first-stage
ammonia leaching solution and first-stage ammonia leaching residues are obtained through
solid-liquid separation, the first-stage ammonia leaching solution is subjected to ammonia
distillation, the pH of the solution obtained after ammonia
distillation is adjusted, then nickel
powder is prepared through adopting a pressurized
hydrogen reduction method; filtrate obtained by carrying out multi-stage ammonia leaching reaction and
solid-liquid separation on the first-stage ammonia leaching residues returns to first-stage ammonia leaching slurrying, filter residues is washed by using a three-stage CCD, then a
carbonization process is adopted, CO2
partial pressure, reaction time and
reaction temperature are controlled, a carbonized liquid and carbonized residues are obtained, and
pyrolysis and
calcination on the carbonized liquid are carried out, then a magnesiumoxide product is obtained; and the
carbide residues are subjected to reduction
smelting through a pyrogenic process, and upper-layer rich-manganous slags and lower-layer nickel-
cobalt-
manganese slagsare obtained after crushing and screening. According to the green method for preparing battery grade nickel
sulfate from the
nickel salt, the method is easy to control, green and energy-saving, the ammonia water and the
ammonium salt in the
system can be recycled, a new process for preparing battery grade nickel sulfate without
wastewater, waste residues and extraction is realized, and the production cost is greatly reduced.