Refractory lining structure

A refractory lining structure for a metallurgical vessel comprising:

• a monolithic first layer having a first surface facing away from a sidewall of a metallurgical vessel and a second surface located opposite the first surface and facing toward the sidewall of the metallurgical vessel, the first layer comprising a first refractory material, wherein the monolithic first layer comprises a thickness;
• a second layer underlying at least a portion of the first layer, the second layer having a first surface facing away from the sidewall of the metallurgical vessel and a second surface located opposite the first surface and facing toward the sidewall of the metallurgical vessel, the second layer comprising a second refractory material, wherein the second surface of the first layer contacts the first surface of the second layer;
• and
• at least one elongated expansion joint formed in the first surface of the first layer and extending through the first surface of the first layer in a substantially vertical direction, wherein the at least one elongated expansion joint comprises a width dimension, a sum of horizontal width dimensions, a depth dimension and a vertical height dimension,
• wherein the sum of the horizontal width dimensions of the at least one elongated expansion joint is characterized by a width ratio of at least 0.010, wherein the width ratio≡
• ∑
• j
• =
• 1
• n
• w
• j
• w
• 1
• ,
• wherein the first surface of the monolithic first layer contains “n” number of the at least one elongated expansion joints, each of horizontal width wj, wherein w1 is a total horizontal width dimension of the first surface of the monolithic first layer on the sidewall.