| 摘要 |
<p>A process for treating and drying a thixotropic prod. contg. solid impurities in the form of insoluble grains, e.g. impure Ca(OH)2 as occurs in the residues of acetylene prodn., comprises (a) kneading the gel to render it liq. making use of its thixotropic properties, with opt. addn. of water to obtain a sufficiently low viscosity; (b) homogenising several batches of the liq. prod. in a mixing buffer tank; (c) removing the solid impurities of size above a certain value by filtration or sieving; (d) dessicating by filtering; (e) crumbling and (f) drying in a heated drier where the combustion gases do not come into contact with the prods. to be dried. The process enables chemically useful prods. to be recovered from slurries which are otherwise rejected as useless. Unlike prior art, it does not require a large amt. of water or result in the Ca(OH)2 coming into contact with CO2 in the combustion gases which might lead to undesired CaCO3 formation.</p> |
