Due to lignite production in open-pit mining, the need to transport overburdened rock also increased, which can be handled cost-effectively by recycling existing equipment like a bridge frame of conveyor belt system. This paper briefly outlines the 3D finite element stress analysis of a bridge structure, which is reused to assist the path of the conveyor belt in the work area. In this paper, the steel bridge, which consists of various structural steel beams, is modeled as a 3D frame using beam elements. Our investigation of the bridge frame refers to the operation of the conveyor belt during transport at full capacity. Considering that the loads applied are derived from only the masses, in this article, the effects of transverse vibrations of the belt are neglected on the structure. The results of the simulations were in favor of reusing the bridge frame, as it has sufficient reserves up to the proportional stress limit.