Patent ID: 9580327
Date: 2017-02-28
CPC Classifications: C01B,G01N

Claim:
1. A method of converting a sample of silicon granules into a form suitable for measurement of the purity of the silicon, the method comprising: placing a volume of silicon granules into a vessel having a surface that defines an upwardly opening cavity having a capacity of ≦500 cm embedding a silicon slug of known purity at least partially in the volume of silicon granules near the leading end; positioning the vessel to pass through an induction coil of an induction heater, the induction coil defining an axially extending passageway sized such that the vessel can pass through the passageway, wherein at least one of the vessel and the induction coil is configured to move axially relative to the other of the vessel and the induction coil; heating the silicon slug with a preheater comprising conductive silicon carbide to a temperature sufficient to couple the silicon slug with the induction heater, wherein the preheater is configured to heat contents of the cavity; inductively heating the preheated silicon slug to a temperature sufficient to melt at least a portion of the preheated silicon slug to form a silicon melt; and moving the vessel or the induction coil generally horizontally such that the vessel passes through the induction coil at a rate to successively inductively heat and melt regions of the volume of silicon granules from the leading end to the trailing end with each region solidifying as the molten silicon exits the induction coil to provide a multicrystalline silicon ingot in the cavity.