I guess I'm not too sure quite what you're asking. But, I will try to answer what I think is your question.
When a/c are deiced on the ground there are several types of deicing fluid that can be used. Generally Type IV
provides the best "holdover" time. Holdover time is basically the length of time the a/c can sit in the conditions before it has to be deiced again. There are charts in the a/c that you can refer to that will determine holdover time. It is based on temp and type of precipitation.
As far as taking off in icing conditions, this is all for the 747-400. It is nothing really too special. There is engine anti icing which would be on, that takes bleed air and heats the cowling to prevent the formation of ice. On the -400 there is also wing heat for deicing of the wing leading. However with flaps out of the up position, the bleed air used for the wing heat is vented overboard. Once the flaps are retracted, you have wing heat available. However, the way the wing on the -400 is designed build up on the leading edge almost never occurs. You will find on the classic and the -400 the application of wing heat almost never occurs.
Hope that helps.