| 摘要 |
The invention relates to a process for the preparation of polycrystalline materials, and to an equipment suitable to the accomplishing thereof. The process comprises the steps of: 1) submitting the material to be crystallized to a heating by means of a resistor which extends vertically, and is positioned around said material, charged on a laterally thermally insulated and open atop vessel, up to a temperature lower by 30 to 100 DEG C than material's melting temperature; 2) submitting the material in the vessel to a further heating from the bottom, up to reaching a temperature greater by 30 to 200 DEG C than material's melting temperature; 3) submiting molten material to cooling, decreasing the heating from the bottom, with a rate comprised within the range of from 0.1 DEG C/minute to 3 DEG C/minute, in a time comprised within the range of from 10 to 30 hours; 4) extracting polycrystalline material in the shape of a slab. The equipment is shown in the figure. |
