27 октября, 2015 
Pokraskin Other production processes are suggested in the patent literature, but have not so far gained industrial importance. For instance, sodium dichromate can be mixed with heating oil and reacted at 300 °C. The soda formed must be washed out prior to calcining at 800 °C to avoid reoxidation in the alkaline melt [3.66].
In alkaline solution, sodium chromate can be reduced with sulfur at atmospheric pressure with formation of sodium thiosulfate. After neutralization, more sodium chromate is added to exhaust the reducing capacity of the thiosulfate. The mixture is calcined at 900-1070 °C [3.67].
Another process involves the shock heating of sodium dichromate in a flame at 900-1600 °C in the presence of excess hydrogen and chlorine to bind the alkali as sodium chloride [3.68]. This method is suitable for the preparation of pigment-grade chromium oxide of high purity, with especially low sulfur content.
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