The invention relates to the technical field of
tin recovery, in particular to a detection method for recovered
tin and a method for preparing a lead-free
tin bar, a tin wire, a tin sheet and a tin bar, and the detection method for recovered tin comprises the steps that S1, the surface of a tin block is cleaned; s2, the tin block is placed in a fluxing agent; s3, the fluxing agent is heated to 240 DEG C to 290 DEG C, so that the tin block is melted into tin beads; and S4, the tin beads are cooled to the
room temperature in the fluxing agent. If black substances exist on the surfaces of the cooled tin balls, it is determined that the recycled tin blocks cannot be used for production. And if no
black substance exists on the surface of the cooled tin bead, the recovered tin block can be directly used for production. Therefore, the quality of the recycled
tin can be quickly distinguished.