METHOD FOR REFINING CRUDE SILICON MELTS USING A PARTICULATE MEDIATOR

• Main Authors: Dr. Konrad Mautner, Dr. Karl-Heinz Rimbck
• Format: Patent
• Language: English
• Published: 04.12.2024
• Subjects: CHEMISTRY; COMPOUNDS THEREOF; FERROUS OR NON-FERROUS ALLOYS; INORGANIC CHEMISTRY; METALLURGY; NON-METALLIC ELEMENTS; PRETREATMENT OF RAW MATERIALS; PRODUCTION AND REFINING OF METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

The subject matter of the invention is a process for oxidatively refining a crude silicon melt in the preparation of industrial-grade silicon, in which process during the refining stage a particulate mediator is added that contains a minimum content of metallurgical silicon of 8 mass % and at least one or more of the elements H, C, O, F, Cl, Ca, Fe and Al, the mediator being described by a characteristic K which has a value of 0.03 to 6 mm-1 and is calculated as follows: (I), (equation 1), where d50,M is particle size (diameter) at 50% of the cumulative distribution on the particle-size distribution curve for the mediator,d50,Med [mm] and em,M is average effective porosity of the particulate mediator.