Experiences in the development of magnesium cell technology at Central Electrochemical Research Institute, Karaikudi

Research activities on the preparation of magnesium metal by molten salt electrolytic process were initiated in CECRI as early as in 1958. CECRI started its experiments on a bench scale level and further developed into pilot plant scale and finally to the scale of semicommercial unit. Various types of electrolytic cells were developed at CECRI which include externally heated cells with different design modifications, modular cells, bipolar/multipolar cells and new modified monopolar ceUs. The primary aim of each development was aimed at high current efficiencies energy efficiencies and space time yields. Various types of raw materials like magnesite, sea bitterns, and byproduct MgCl2 from ZrrTi plants etc. were utilised during the investigations. These studies were carried out with financial grants from Govt. of Tamil Nadu, CSIR, DRDO and Nuclear Fuel Complex. The paper illustrates the design and operational features of different electrolytic cells with consequent gradual decrease in specific energy consumption for magnesium production and increased space time yields with improvement in cell design and operational parameters

Bipolar cell for production of magnesium

Bipolar type of cells appear to be promising in the field of fused chloride electrolysis as found in the case of ALCOA type aluminium cells. The adoption of this technique for magnesium production could also lead to design of improved type of cells which would result in further cost reduction. CECRI with its experience on building modular cells without the diaphragm has conducted trial experiment's on bipolar systems for magnesium production. The preliminary results obtained from a cell of 500 A capacity is discussed