| 摘要 |
1,241,797. Roadstone. J. G. JAMES and J. R. HOSKING. 13 Aug., 1968 [22 Aug., 1967], No. 38630/67. Heading C1H. An artificial roadstone having a Polished Stone Value of at least 45 comprises a waterinsoluble abrasive of a Moh hardness of at least 6 bonded in a matrix of a water insoluble of a Moh hardness of at least 3 but less than that of the abrasive. 5-75% sized 2.5 mm. to 50 microns of the abrasive is preferred examples being calcined bauxite and kyanite, quartz, garnet, cordierite, emery, sillimanite, crushed grinding wheels and crushed refractory bricks. Matrices specified are fired earths, glasses, mortars, slags, silicates, clays, fly ash and red mud. In an example bauxite is added to a high alumina cement and limestone. |
