| 摘要 |
<p>Briquettes having a high green strength and a high strength after drying are produced from a finely divided natural or synthetic magnesium compound which yields magnesia, on firing, e.g. raw magnesite which has been freed from impurities by flotation by forming a solid, water-containing mixture of the magnesium compound and flue dust obtained by firing magnesite, subjecting the moist mixture to the action of gaseous carbon dioxide and thereafter pressing the mixture to form briquettes. The mixture preferably contains neutral or basic salts (e.g. MgSO4, preferably kieserite or epsomite) or solutions thereof in amounts such that the mixture contains 0.3-1.5 per cent by weight of these salts. The neutral or basic salt solutions may be added to the mixture before and/or after treatment with CO2. If MgSO4 solution is added it is preferably 29-32 DEG Be-. The carbon dioxide may be used in the form of exhaust gases which contain CO2. The "flue dust" (primarily caustic magnesia) is used in amounts of 5-30 per cent by weight based on the mixture of magnesia-yielding compound and flue dust. The mixture is preferably pressed into briquettes 30-60 minutes after its preparation.</p> |
