Patent ID: 11920214
Assignee: DEREF S.P.A.
Field: Materials, metallurgy (Chemistry)
Classification: CPC C  B  Y | IPC B  C

Claim 0:
1. A method for recovering spent refractory material in one or more steel plants and reusing finished product of recovered spent refractory material, the method comprising the following steps:
a) receiving refractory material coming from demolition of refractory material linings in containers used in steel making, treatment and manufacturing processes, wherein the refractory material includes basic refractory parts comprising at least one of magnesic material and dolomite material,
b) sieving and separating the refractory material, and
c) collecting the refractory material,
wherein
step b) comprises the following sub-steps:
b1) first sieving of the refractory material into at least two fractions on the basis of a first specific threshold size value, so as to identify a fine fraction and a coarse fraction,
b2) magnetically separating the fine fraction, and
b3) magnetically separating the coarse fraction into at least one of a magnetic metal part, a nonmagnetic metal part, and a refractory part, and wherein said coarse fraction is fragmented into small granules,
b4) second sieving of the fine fraction into three different sub-fractions on the basis of two second specific threshold size values,
b5) identifying two sub-fractions with greater size, and
b6) nonmagentically separating the two sub-fractions with greater size such that nonmagnetic metal parts are separated with respect to fine parts,
b7) producing basic granulate materials as a finished product by a grinding operation of the small granules in combination with said fine parts, wherein the basic granulate materials consist of raw material usable in a melting process in an electric furnace; and
b8) partially replacing lime necessary for the melting process in the electric furnace by disposing slag conditioner into the electric furnace, wherein slag conditioner comprises the raw material of the basic granulate materials.