| 摘要 |
<p>Molar ratio phosphate to sulphate is form 1:1 to 1:9 and particle size 0.01-10 microns. A suspension of an alkaline earth hydroxide is mixed with phosphoric acid and simultaneously or subsequently with sulphuric acid. If the sulphuric acid is added subsequently, additional alkaline earth hydroxide is added at the same time.</p> |
