Ferro silicon nitride is a Si3N4 as the main ingredient，along with free iron, no-nitride Ferro Silicon and small amounts of other components of the mixture. Ferro Silicon Nitride of refractory is a kind of gray powder,and it is the gray granular matter when used for steel making.

The powder ferrosilicon is mainly used for the closure of a large blast furnace taphole clay, and a small amount of it is used in the iron ditch material or other unshaped refractory materials.

The granular ferro silicon nitride is mainly used for oriented silicon steel or other steels that use nitride to increase strength (such as HRB400 rebar).

Ferro Silicon Nitride in the blast furnace taphole clay are universally applied in the developed countries to significantly improve the opening blocked and meet the needs of the blast furnace.It is an indispensable ingredient of modern large-scale blast furnace taphole clay. adding a small amount of ferro silicon nitride in ferrous material greatly improve the iron content of iron trough. Japan began to use it in the 1970s.

The domestic application of ferro silicon nitride is in a relatively short time, Baosteel first added ferro silicon nitride to blast furnace taphole clay, the taphole clay properties are improved to meet the needs of Baosteel, many other steel mills in China are basically using ferro silicon nitride, Adding ferro silicon nitride stemming is very good to meet the needs of large-scale blast furnace,  the blast furnace tapping times from 18 decreased to 12, the lowest down to 6, the consumption of taphole clay reduced by 1.2kg/ tons of iron to 0.5kg/ tons of iron.In the past 3 years,  the blast furnace tap hole clay that above 2000M3 of the national key large-scale iron and Steel Enterprisesare are basically using it.