| 摘要 |
<p>Cement base material is prepared by mixing moist powdered calcium sulphate dihydrate with Portland cement or Portland cement clinker, in a proportion of 70-80 kg calcium sulphate dihydrate, calculated as dry product, to 30-20 kg. cement or clinker, and then allowing the moisture present to react with the cement or clinker. The calcium sulphate dihydrate is pref. a waste gypsum produced during the preparation of phosphoric acid from phosphate rock by the wet process. The cement base material can be easily mixed with cement to form uniform mixtures.</p> |
