| 摘要 |
<p>The way of talc treatment consists in the mixing-up 74 up to 89 weight % of water, 10 up to 20 weight % of talc and 1 up to 6 weight % of hydrochloric acid and the resulting substance is heated at constant stirring in 0.5 up to 6 hours to the temperature 40 °C up to 60 °C and it is maintained at this temperature during 1 up to 6 hours. Out of the reaction mixture there is afterwards separated the sediment and following the adjustment of its acidity to the pH value 5 up to 8 it is mixed with water and sulphuric acid in the ratio 10 up to 20 volume % of sediment, 74 up to 89 volume % of water and 1 up to 6 volume % of sulphuric acid in dependence with the laboratory temperature, and at constant stirring is the reaction mixture heated during 0.5 hour up to 6 hours to the temperature 75 °C up to 125 °C and it is maintained at this temperature until the time when there is reached a quasi unchangeable value of the iron content in the reaction mixture, and then the sediment is separated, its acidity is adjusted to the pH value 5 up to 8 and subsequently it is dried and sterilized at the temperature 160 °C up to 250 °C during two up to four hours.</p> |
