The invention relates to a method for co-production of chromate from
chromite and
ferrochrome, and the method comprises the following steps: firstly, carrying out first
liquid phase oxidation reaction on
chromite, aqueous alkali and
magnesium iron
slag, and then sequentially carrying out cooling, slurrying reaction and
solid-liquid separation to obtain a first reaction
solid phase; then, the first reaction
solid phase obtained in the step (1) is sequentially subjected to first washing treatment and second washing treatment, and a second washed
liquid phase is obtained; then, evaporating and concentrating the second washed
liquid phase to obtain a concentrated solution; and finally, carrying out a second liquid-phase oxidation reaction on the ferrochromium, the iron
slag and the concentrated solution, and then sequentially carrying out cooling and solid-liquid separation to obtain a chromate solution. The method provided by the invention has the advantages of simple process, lower
energy consumption and cost, less
water consumption and the like, does not have an
evaporation and concentration process of high-concentration alkali, does not
discharge waste residues, has strong
operability and is easy to industrialize.