| 摘要 |
<p>A method for producing bleaching earth from clay which comprises providing uncalcined naturally-occurring acidic clay selected from (a) palygorskite clay containig at leat 90 wt.% attapulgite and (b) mixtures of palygorskite and bentonite clays, mixing said clay with an acid solution in amount corresponding to an acid dosage of 1 to 10% by weight, reacting said clay with said acid (e.g. at a temperature of 25 to 99<o>C), and recovering said reacted clay for use as a bleaching earth.</p> |
