A hydrothermal oxidation method for production of alkali metal dichromate from carbon ferrochrome

A hydrothermal oxidation method for the production of alkali metal dichromate from carbon ferrochrome is provided. The method involves the following steps: preparing primary reaction liquid by mixing carbon ferrochrome, alkaline substance and water and controlling the amount of the alkaline substance employed practically lower than that required theoretically; adding the primary reaction liquid in a reaction kettle and filling oxygen; reacting for 0.5h~3h under the conditions of 150 ~370 and 2Mpa~24Mpa; separating solid from the liquid, cooling the obtained filtrate to -12 to -20 , precipitating crystals and centrifugally separating to obtain the solution of alkali metal dichromate; increasing the acidification rate to greater than or equal to 100% by adding CrO3 into the solution of alkali metal dichromate; evaporating and concentrating, cooling and crystallizing, thereby obtaining alkali metal dichromate. Said method is a simple process and easy to control, which can be used to directly produce sodium dichromate under hydrothermal condition.