| 摘要 |
<p>Absorption of SiF4, from e.g. gases evolved during dissolution of phosphate ores with H2SO4, in water or a H2SiF6 soln. in two slit-plate absorbers connected in series to obtain conc. H2SiF6 soln. as in the DL 67408 is improved by cooling the gases by addition of cold air so that the temp. of the suspension is 50-60 degrees C and a conc. of 20-30% H2SiF6 is attained. By this method, the deposition of silica due to dehydration above 60 degrees C is avoided.</p> |
