Production of silicon of improved purity
Реферат: <PICT:0872282/III/1> In the production of pure silicon by reacting impure silicon with iodine vapour, recrystallizing the resulting silicon tetraiodide, e.g. from n-heptane, distilling the recrystallized tetraiodide, and depositing silicon from the vaporized tetraiodide on a heated surface, the silicon and iodine are reacted in a fluidized bed of the silicon. The silicon may have a particle size of 44-100 microns and the temperature of reaction may be 500-1000 DEG C. The silicon may be deposited on a rod or hollow cylinder of silicon, silica, or tantalum. The temperature of deposition may be 1000 DEG C. Heating may be by induction. The silicon deposition surface may have a resistivity of 100-200 ohm cm. The product may have a resistivity of 3000-13,000 ohm cm. and contain 2-9 X 10-11 atoms impurity per atom of silicon. As shown silicon tetraiodide is produced in a fluidized bed contained in a quartz tube 7 heated by an electric element 11 in a furnace 8. The product is condensed in a jacketed vessel 14 of glass lined steel and recrystallized therein. The recrystallized product is passed to a distillation column 17, reboiler 19, and condenser 20, of quartz. The distilled product is passed to a vaporizer 21 and a decomposer comprising a quartz tube 23 containing a silicon rod 24 heated by an induction coil 25.
Method of producing high purity silicon powder from mixture of silicon dioxide and aluminium
Номер патента: RU2648436C2. Автор: Сергей Павлович Андреев,Николай Николаевич Лавров,Юрий Петрович Удалов,Борис Александрович Лавров,Галимжан Мендикараевич Сержанов. Владелец: Общество с Ограниченной Ответственностью Научно-Производственное Предприятие "КЛИН". Дата публикации: 2018-03-26.