Process and equipment for producing nodular graphite cast iron

摘要

The conventional procedures in the production of nodular graphite cast iron by means of pure magnesium in iron foundries are affected by substantial disadvantages. These include low productivity per unit time, high transport costs, intensive personnel use, inaccuracy of the magnesium analysis in the cast iron and high magnesium losses from the cast iron melt as a function of time. To solve the problems, a process and equipment have been found in which the equipment forms a treatment space in a treatment vessel bottom, the treatment vessel being filled with molten cast iron and the latter penetrating into the treatment space filled with pure magnesium. A reaction of the magnesium to form a magnesium alloy in the molten cast iron then takes place. A treatment vessel has advantages if it is designed as vacuum treatment vessel, because in this case, in conjunction with a cast iron receiver, partial automation of the step of filling of the treatment vessel is possible via a level indicator with control. If the finished molten cast iron must be held in the vacuum treatment vessel for a prolonged period, magnesium losses are avoided by the use of blanketing gases.