Particulate metallurgical hot topping compositions and method of use

摘要

Preparation of particulate metallurgical hot topping compositions that react in situ to form a protective cover over the exposed surface of as-cast ingots. The compositions consist essentially of 9 to 33 percent by weight of oxidizing constituents, 40 to 65 percent by weight refractory constituents and 15 to 45 percent by weight of fuel constituent. Careful control of the quality and size of the major fuel constituent minimizes smoke evolution during reaction of the composition and subsequently if the covering is disturbed. By varying the ingredients in the hot topping composition, there can optionally be produced (1) a hard crust so that the as-cast ingots can be moved before a major portion of the ingot has solidified (2) a medium density crust for delayed addition of a highly exothermic hot topping composition, or (3) a low strength crust for "back-pouring" practice.