| 摘要 |
<p>1326850 Moulding building bricks F L SMIDTH & CO AS 28 Oct 1971 [3 Nov 1970] 50243/71 Heading B5A In a method of producing building blocks, a mixture of flint and limestone is in sequence burned, ground, hydrated, moulded and autoclaved, these steps being carried out in direct succession. The burning takes place at 1000- 1200‹ C. and the resulting mixture is ground to a particle size of 0À2 mm. The hydration process is carried out at a temperature of less than 80‹ C., and is of such brief duration that only insignificant amounts of hydrated limestone and flint react with each other prior to the autoclaving process, in which the mixture is hardened.</p> |
