海水マグネシアの製造法と成分 (第3報)

抄録

In continuing the previous studies (This Journal, 59 456-461 (1951) and 60 540-544 (1952)), the present authors reported in this third paper the results of the further studying on the manufacturing sea water magnesia by the special method. The main points of the process and results are as following, (a) Dolomite obtained from the famous dolomite bed at Kuzuu in Tochigi Pref., was mixed with 3 or 5% limonite, calcined at 900°C for 2 hours, slaked with water to dolomite milk, and then to 10% dolomite solution, (b) Bittern of Bé 32° was diluted about four times with water, (c) The diluted dolomite solution and the dilute bittern solution were reacted to prepare magnesium hydroxide, by changing various conditions, e.g., (1) The concentration of dolomite solution, (2) The reaction temperatures, (3) The molecular ratio of CaO in the dilute dolomite solution to MgO of magnesium salts in the dilute bittern solution, etc., (d) The various samples of thus prepared magnesium hydroxide were analysed and compared with those from various factories manufactured by lime water and sea water or bittern. The lime content in the prepared samples was about 4-5%, which is smaller than that (about 8-14%) of the factory samples, but this lime content must be further reduced to 1-2%, to obtain the suitable magnesia clinker for various magnesian basic refractories.