Magnesium is the 8^th most abundant element and constitutes 2% of the earth's crust. It is present at 0.13% in seawater. Magnesium and its compounds are produced from seawater, well and lake brines and bitterns, as well as from minerals like Magnesite.

High purity magnesium oxide for sintered magnesia refractories is made by pyrohydrolysis of magnesium chloride brine. The presence of boron in the magnesium chloride brine is undesirable because boron embrittles the magnesia ceramics during drying operations. The presence of boron also prevents the coalescence of magnesium metal during electrolysis of fused magnesium chloride salts.

In both cases, boron can be removed from the magnesium chloride brine by using Amberlite™ IRA743 which is a boron-selective resin with N-methyl glucamine functionality. Amberlite™ IRA743 is capable of reducing boron concentrations from around 100 ppm to <10 ppm in 12% MgCl_2.

 

 

 

 

Fig. 1: Boron Removal Process   Column Position Step Loading Polishing Regenerating 1 A B C 2 B C A 3 C A B     Typical Operating conditions*     Process configuration Merry-go-round with 2 or 3 columns Influent Composition 100 ppm Boron in 12% MgCl2 Flow rate 16 BV/h Typical operating capacity 2 g/LR Regenerant mode Co-flow Regeneration step 10% H2SO4 (50 g/LR) Conversion step 4% NaOH at 4 BV/h for 30-45 min (80-120 g NaOH/LR) Regeneration 4% NaOH (65 g/LR) or 4 % NH4OH (50 g/LR) Effluent quality < 10 ppm B   * depending on the plant lay out, acceptable leakage levels and influent composition, these values may change considerably.     Recommended Product   Amberlite™ IRA743 Very low boron leakage. Excellent operating capacity and low regenerant consumption. High physical and chemical stability. Improved operating capacity.     For sampling, pricing, availability or more information please contact your Rohm and Haas representative. Back