Co precipitation Technique
In this method first mixture of Magnesium Nitrate or Magnesium chloride and Aluminium Nitrate are mixed in a ratio of 1:2 and 30% ammonium hydroxide is added to increase the pH of the system to level of pH 10 at a temperature of 60 to 80oC. In this stage reaction takes place and co precipitation of the hydroxides happens.
The precipitate formed is aged for one day for stability and full reaction. The precipitate solution is filtered and the precipitate is washed with water and the washed precipitate is dried and pulverised.
The powder is then calcined in a furnace at about 1100oC so as to form the pure spinel powder of particle size less than 200 to 300 nano metre.
To be contd…
