Hi Samir22!
You can see the methods in the books of Inorganic Chemistry.
It's obtained by reduction with combustion of K2Cr2O7 +S
The potassium dichromate can be sustituted by sodium dichromate,more cheap,and the sulphur by organic matter: glucose or other carbohydrate.
The better materials for nozzles at high temp. and abrasion are made with silicium carbide, silicium nitride or mix of the two.Ask to makers of ceramic kilns.