Ladle Clause Samples

Ladle. ‌ The material flow from the ladle to the casting mold is characterized by a specific chemistry, a temperature and a mass flow rate. All of these parameters are in principle dynamic in nature. The change of composition during casting is by experience rather small and is to a first approximation considered constant. In principle, the composition change could be measured with a standard dip sample, taking samples at the beginning and at the end of the casting. However, there are several practical issues concerning access to the melt during casting. Perhaps the easiest way of sampling is to take a sample from the melt as it flows out from the ladle. The temperature of the silicon leaving the ladle (and thus entering the “casting process”) can be measured in several ways. 3.1.1 Dip temperature measurement in ladle‌ The normal way of using a hand-held probe is technically feasible, low cost and accurate. However, the access to the ladle as it is continuously tilting over is very poor. The intense radiation from the molten bath and ladle effectively prevents the operator to be located in front of the opening. Thus, he can have no direct visual contact with the silicon inside the ladle as the measurement is done. This method has practical limitations due to limited access and multiple issues regarding safety for the operator carrying out the measurement. The long-term strategy for Elkem is to remove all personnel from hazardous areas, including by or near a ladle filled with molten silicon. As such, dip measurements are disregarded as means of obtaining the temperature of the silicon before casting. 3.1.2 Continuous temperature measurement within ladle‌ The development of the Dyntemp® system by BFI and Minkon has opened up the opportunity to measure the temperature in the molten silicon in a far more elegant way than dip measurements. The basic idea is to insert the fiber optic wire with the refining gas through the bottom plug. A temperature can then be obtained throughout the casting process, if desirable. The involvement of humans is kept to a strict minimum as the Dyntemp system is fully automatic.