| 摘要 |
<p>Method for extracting and providing in desired composition of granular material, comprising the following steps of: sucking or scooping (6) up granular material; separating (7,9,10,11,12,13,14,15) the granular material into fractions (B,C,D,E,F,G); mixing the granular material into a mixture of the different fractions; and adding granular material from a fraction insufficiently available at the extraction location. 2. Installation for extracting and providing granular material, for instance sand and gravel, in desired composition, comprising: means for sucking or scooping (6) up granular material; means for sorting (7,9,10,11,12,13,14,15) the material into two or more grain size classes; means for mixing the material from the classes into a mixture of granular material; and means for adding one or more additives to the mixture. <IMAGE></p> |
