초록 ▼

A process for the production of silicon or ferrosilicon by reduction of silicon oxide, optionally in the presence of iron oxide, by means of a carbonaceous reducing agent in a reduction furnace. The furnace operation is simplified and the yield is increased by making the supply of energy and the sup

A process for the production of silicon or ferrosilicon by reduction of silicon oxide, optionally in the presence of iron oxide, by means of a carbonaceous reducing agent in a reduction furnace. The furnace operation is simplified and the yield is increased by making the supply of energy and the supply of silicon oxide, respectively, independent of each other and by adjusting the ratio between them in such a manner that the gases leaving the furnace have a silicon monoxide content below 10 mole percent. A controlled supply of at least a part of the silicon oxide to the hotter parts of the furnace can be used as a means of making the supply of energy and the supply of silicon oxide reciprocally adjustable.

대표청구항 ▼

A process for the preparation of silicon or ferrosilicon by reduction of silicon oxide in the form of silicas or cation containing silicates and oxides, optionally in the presence of iron or iron oxide, by means of a carbonaceous reducing agent in a reaction zone, which reaction zone comprises a zon

A process for the preparation of silicon or ferrosilicon by reduction of silicon oxide in the form of silicas or cation containing silicates and oxides, optionally in the presence of iron or iron oxide, by means of a carbonaceous reducing agent in a reaction zone, which reaction zone comprises a zone of energy supply and a zone of subsequent reaction, whereby at least energy and condensed phases from the zone of subsequent reaction are brought to the zone of energy supply while silicon product and a gas phase are leaving the zone of energy supply and whereby at least carbonaceous reducing agent and the gas phase from the zone of energy supply are brought to the zone of subsequent reaction while a gas phase product and condensed phase are leaving the zone of subsequent reaction so that the gas phase product leaves the reaction zone and the condensed phases enter the zone of energy supply and whereby the silicon oxide is supplied in condensed form somewhere in the reaction zone or in gas phase to the zone of energy supply, comprising the steps of: (a) supplying at least 33 percent of the silicon oxide directly into the zone of energy supply through a channel through the furnace wall, or a channel through the charge or a channel through the electrodes, (b) controlling the supply rate of the silicon oxide to the zone of energy supply essentially continuously and in an adjustable way to make the consumption of the silicon oxide in the zone of energy supply independent of the charging of energy to the zone of energy supply so that the temperature in the zone of energy supply can be influenced, and (c) regulating the supply rate of silicon oxide and the supply rate of energy to the zone of energy supply to give a high enough temperature in the zone of energy supply to give a content of silicon monoxide below 5 mole percent in the gas leaving the zone of subsequent reaction.