| 摘要 |
<p>Sodium fluosilicate is reacted with ammonia in a continuous or discontinuous process, to form ammonium fluoride and other materials separable by conventional physical means. The discontinuous process is carried out by placing an aq. sodium fluorosilicate slurry in a reactor, adding ammonia as an aq. soln. or gas, in amount above stoichiometric, subjecting to strong agitation, and maintaining at 60-90 deg. C. The ammonia is added over 15-120 minutes and the digestion time is 30-60 minutes, with a final ammonia excess of 2.5-25%.</p> |
