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

Electro-refining of aluminium

Bench scale cells of MO A capecity have been designed and operated for electrowfining of aluminium, incorporating nome improvements in the design Factors to be studied are alloy composition. electrolyte composition, operating parameters like current derisity, interpolar gap, developing a suitable method of feeding the impure metel and rembving the purified aluminium

An electrolyte for energy efficient magnesium electrolytic cells

153-156<span style="font-size:11.0pt;line-height: 115%;font-family:Calibri;mso-fareast-font-family:" times="" new="" roman";mso-bidi-font-family:="" "times="" roman";mso-ansi-language:en-us;mso-fareast-language:en-us;="" mso-bidi-language:ar-sa"="" lang="EN-US">The new generation cells for magnesium metal extraction such as bipolar cells are energy efficient. In such cells, the electrolyte composition plays a major role in obtaining pure metal with less energy consumption. To identify such an electrolyte, a series of experiments have been carried out with alkali and alkaline earth chlorides. A ternary composition consisting of magnesium chloride, sodium chloride and potassium chloride has been found suitable.</span

A new electrorefining system for aluminium

Super pure aluminium is at present produced on commercial scale by three layer electrorefining process which has several drawbacks. A new nonalloying refining system was hence developed and tried in laboratory scale cells. The performance of the new system and the results obtained therein are discussed in this pape

Intraspecies variation in sodium partitioning, potassium and proline accumulation under salt stress in <em>Casuarina equisetifolia</em> Forst

International audienceCasuarina equisetifolia Forst., a member of the Casuarinaceae family, is widely planted in coastal areas due to its ability to function as potential barrier against wind and waves. Significant variation has been reported in the ability of C. equisetifolia to grow under salinity stress. In the present study, 82 clones of C. equisetifolia were assessed for their response to 50 mM incremental NaCl concentrations ranging from 50 mM to 550 mM in Hoagland's solution and clones with contrasted salt tolerance were identified. Several earlier reports attribute salt sensitivity in Casuarina species to the toxic effect of sodium. Intraclonal variation in the levels of sodium accumulation was therefore analysed. However, sodium content in the shoots and roots, showed little correlation (0.351 and -0.171) with salt tolerance in C. equisetifolia. Similarly, sodium to potassium ratio in the shoots and roots of NaCl treated and untreated clones also did not show correlation with mortality although certain tolerant clones exhibited selectivity of potassium over sodium under salt stress. Analysis of the shoot to root ratio of sodium however, showed better correlation (0.448) with salt tolerance, suggesting that restricted translocation of sodium to shoots and its relative retention in roots might play a crucial role in the salt tolerant clones of C. equisetifolia, and that shoot to root ratio of sodium could be a better parameter for salt tolerance in C. equisetifolia clones. The higher salt tolerance observed in certain clones despite higher sodium accumulation or shoot to root ratio of sodium suggests the presence of different multiple adaptive mechanisms that may be operating in different clones to help protect the cells from the toxic effects of sodium. The tolerant clone, TNIPT 4, which accumulated high concentrations of Na+, had low shoot to root ratio of Na+, and also a higher constitutive as well as NaCl induced accumulation of the compatible osmolyte, proline. The study thus emphasizes the need for characterising the genetic components involved in sodium transport, proline metabolism and other mechanisms contributing to salinity tolerance. The identified clones with contrasted stress tolerance mechanisms would thus be a valuable resource for transcriptomic, proteomic and metabolomic exploration in addition to their utility for field evaluation in flooded and coastal saline tracts