Birch, Stewart, Kolasch & Birch
Process for the preparation of magnesium chloride for use as an electrolyte in electrolytic production of magnesium metal
 In electrolytic production of magnesium metal the concentration of magnesium chloride in the bath is required to be replenished periodically or continuously. This magnesium chloride should be anhydrous and of certain specifications. This invention provides a method for the production of such anhydrous magnesium chloride in a two-stage dehydration of magnesium chloride solution, the first step consisting of preparation of a fine powder from magnesium chloride with 0.5 to 1.5 molecules of water and about 4 to 10% magnesium oxide with or without alkali or alkaline earth metal chlorides, or both depending on the starting material. This first step is carried out in a conventional apparatus like the spray drier, briquetting the above partially dehydrated product in admixture with carbon powder under pressure to obtain compacted material such as briquettes of bulk density of 0.6 to 1.3 g/c.c., and size 1.5 to 5 cm. Second step comprises heating the above briquettes to a temperature of 200.degree. to 350.degree. C. in a current of chlorine gas for a period of 2 to 4 hours to obtain a completely dehydrated magnesium chloride with reduced magnesium oxide content suitable for electrolysis. 
Council of Scientific and Industrial Research
C C
C01F C25C
inventional inventional
Kadathur S. Poonamalle Narasimhan Koyalmannam S. Chanassery O. Thangaraj S. Handady V. Gajavalli N. R. Arunachalam Panchapagesa Srinivasa Somasundaram Laguduva K. I.
Srinivasan Srinivasadesikan Rajagopalan Dhandapani Augustin Devasahayam Udupa Kannan Selvakesavan Subramanian Srikantan Sukumaran Srinivasan