TW200904750A - Method for the initial start of reaction in a process for the direct chlorination of silicon metal or a silicon containing meterial at a low temperature - Google Patents

Abstract

Method for the initial start of reaction when producing silicon tetrachloride by reaction of silicon metal, ferrosilicon, silicon oxide, and/or silicon carbide with chlorine in fluid bed, fixed bed or disappearing bed reactors. The temperature at the start of chlorination (ignition) is at or close to ambient temperature (room temperature), whereby a small amount of an ignition or reaction initiation material such as an alloy and/or compound that readily reacts exothermally with chlorine at or close to ambient temperature thereby raising the temperature of the adjacent silicon or silicon containing material to a temperature above the chlorination ignition temperature of silicon or the silicon containing material.

Description

200904750 IX. DESCRIPTION OF THE INVENTION: TECHNICAL FIELD The present invention relates to a reaction in a fluidized bed, a fixed bed or a hidden bed reactor by using ruthenium metal, lanthanum iron, cerium oxide and/or lanthanum lanthanum and gas. The method used to initiate the reaction when ruthenium tetrachloride is used. [Prior Art] The reaction of base metal with chlorine is characterized by a very high positive reaction 仟 687 仟 joules per mole of siC. This high energy release poses major challenges and explains why other methods have been more attractive for industrial use than direct chlorination. The second question relates to the onset of chlorination, which can be determined at a gas pressure of 1 atmosphere in a typical fluidized bed reactor for direct gasification of base metals, depending on the quality of the crucible, at 35 〇 4 〇 Hey. Start within the scope of 〇. When the partial pressure of C 〖2 is lower, the ignition temperature is increased. For example, under the pressure of 〇 33atmCi2, the ignition temperature was found to increase to 400-500t:. This rather high degree of fire creates a need for an auxiliary heated gasification reactor in the form of a gas/oil burner or a more complex heat exchanger system that is heated by resistance, induction heating, or placed directly on the wall. When the main challenge is to remove excess heat, the auxiliary heating system may cause additional problems after starting the reaction. SUMMARY OF THE INVENTION The present invention represents a method for solving the above heating problem and can be applied to a "L body bed solid boring bed or a hidden bed reaction to directly ruthenium ruthenium metal, ruthenium iron, 200904750 ruthenium oxide and/or ruthenium carbide. The present invention is characterized in that (4) η consumption is defined as _# points as defined in the independent item of the stipulations. The preferred embodiment of the present invention is in the subsidiary of the T-Kiss patent range 2-6. The invention is characterized in that the temperature at the beginning of the chlorination can be lowered to a close by a small amount of ignition or a reaction inducing substance such as a pro-introduction of tin (Sn).

Around - degrees 'about 40.不需要 No external training is required above this temperature. The reaction between sn and Cl2 to form tin tetrachloride (SnCl4) is exothermic; the reaction is carried out by 川 仟 joule/mole Sncl4. The heat released during the vaporization of Sn heats the surrounding feed to a temperature above the ignition temperature of the chlorinated Si. The amount of Sn in the initial charge should be large enough to ensure that the reaction is carried out for a period of time sufficient to heat the adjacent particles containing particles above the ignition temperature of Si. Depending on the reactor type (fluidized bed, fixed bed or hidden bed) and the type and size distribution of the cerium-containing particles and tin particles, the molar ratio of Sn in the initial charge should be in the range of 0.05-5%. The invention is not limited to the use of Sn pre-ignition. Other elements, alloys and/or compounds may be used provided that it reacts readily with chlorine to produce a sufficient heat at significantly below 35 〇t:2 /JEL to eliminate the reaction to external heating requirements. Examples are solders with a high tin content, white bearing alloys with high tin content (Babbit metal) and tin-lead alloys. Sulfides of Sn and Sb (SnS2 and St^S3) can also be used. These sulfides can be reduced by gas to form sci2. In addition, trace reaction products that may contaminate SiCh should be separable from siCl4. If SiCl4 is later reduced to high purity Si for use in the solar or electronics industry, then

Claims (1)

200904750 X. Patent application: 1. A method for producing antimony tetrachloride by reacting rhodium, ferroniobium, cerium oxide and/or cerium carbide with chlorine in a fluidized bed, fixed bed or a hidden bed reactor. The method of initiating the reaction, characterized in that the temperature at which the chlorination starts (ignition) is at or near the ambient temperature (room temperature), by igniting a small amount or reacting the starting material as easily or near the surroundings. An alloy and/or a compound that exotherms with gas at a temperature is added to the reactor, thereby bringing adjacent crucibles or The temperature of the stone-containing material is increased to the temperature above the gasification ignition temperature of the material or cut (4). The method of claim 1, wherein the ignition material is added in an amount corresponding to 5 mol% of the initial ♦ content of the cut feed. · 3. According to the scope of the patent application, the ignition material is tin. 4. According to the scope of the patent application, the ignition material system is added. 5. According to the scope of the patent application, the ignition material is a tin-based alloy containing niobium. 6. According to the scope of the patent application, the ignition material is a sulfide of tin or antimony or a method of two items. 'A method characterized by or 2, characterized in that the method of 〇 or 2 is characterized by Benefit diagram: