| 摘要 |
<p>A ferrous sulphate hydrate product for use as chromate reducing agent for dry cement is made from a technical or commercial grade ferrous sulphate heptahydrate by one or more treatments selected from moderate drying, powder dilution, physical absorption, and chemical absorption. In particular, the technical grade ferrous sulphate heptahydrate is mixed with fly ash or gypsum and subjected to a moderate drying at temperatures in the range of 20-60<o>C.</p> |
