A kind of method for preparing potassium dichromate crystal from chromite in microwave field

Abstract

The invention relates to a method for preparing potassium dichromate crystals by chromic iron ores in a microwave field, and belongs to the technical field of chromium salt preparation. The method includes the steps: firstly, uniformly mixing chromic iron ore powder with the particle size smaller than 0.75 micrometer and sodium carbonate solids, heating to the temperature of 750 DEG C by the aid of microwaves, performing reaction for more than 60 minutes, and naturally cooling mixture to the indoor temperature after reaction to obtain oxidizing roasting products; grinding the obtained oxidizing roasting products to powder, adding water to ultrasonically leach to obtain sodium chromate solution, and filtering the sodium chromate solution to remove impurity Fe2O3 solids; continuing to add CH3COOH into the sodium chromate solution removed the impurity Fe2O3 solids to adjust pH (potential of hydrogen) to be smaller than 5, adding KCl solids, performing evaporation and contraction, and filtering, washing and drying cooled crystals to obtain the potassium dichromate crystals. The method is low in reaction temperature and short in technological process, and the conversion rate of chromium is high.

Description

technical field

[0001] The invention relates to a method for preparing potassium dichromate crystals from chromite in a microwave field, and belongs to the technical field of chromium salt preparation. Background technique

[0002] Potassium dichromate crystals are mainly used in the chemical industry as the main raw material for the production of chromium salt products such as chromium trioxide. The match industry is used as an oxidizing agent in the manufacture of match heads. The enamel industry is used to make enamel enamel powder, which makes enamel green. The glass industry is used as a colorant. It is used as a mordant in the printing and dyeing industry. The spice industry is used as an oxidizing agent, etc. In addition, it is also one of the important reagents for testing the chemical oxygen demand (COD) of water. Its acidic aqueous solution can detect ethanol, and will quickly generate blue-green trivalent Cr ions when encountering ethanol. The acidified pota...