The Recovery of Metallic Tin from an Industrial Tin-Bearing By-Product Containing Na2SO4 by Reduction Smelting Process

Jongshin Chang,Hosang Sohn

doi:10.3390/met11111697

Abstract

Tin was recovered in metal from an industrial tin-bearing byproduct containing Na2SO4 by carbothermic reduction smelting, and the effects of basicity (Na2O/SiO2), temperature, and reaction time on the recovery of tin were studied. Na2SO4 was reduced by carbon and formed into sodium silicate slag (Na2O–SiO2) in the presence of SiO2. Tin content in slag decreased with the increase of Na2O/SiO2 ratio in slag, temperature, and reaction time, but the recovery of tin was affected by volatilization of tin in high temperature and high silica region of basicity. In this study, the maximum recovery rate of tin was 94.8% at the experimental condition of 1200 °C, 2 h, and 0.55 of Na2O/SiO2 ratio. The major impurities in produced metal were Bi, Pb, Cu, Fe, and most of Bi, Pb, Cu were distributed to the metal phase, but the distribution of Fe was closely related to basicity.

Highlights

Tin has been widely used in electronic solder, tinplate, alloys, and chemicals, and it is crucial for the future because it is a key metal to both the Fourth Industrial Revolution and the Green Revolution
The recent copper smelting industry treats a lot of e-wastes as a secondary resource, and tin, used as a soldering material on the printed circuit board (PCB) of electronic devices, comes into the copper smelting industry
It is expected that more tin would flow into the copper smelting industry because the amount of collected e-wastes has been increasing due to recent advancement in electronic and electrical technologies [3], and in addition, there has been much development of alternative solder alloy largely based upon tin due to environmental issue of lead-based solder [4]

Summary

Introduction

Tin has been widely used in electronic solder, tinplate, alloys, and chemicals, and it is crucial for the future because it is a key metal to both the Fourth Industrial Revolution and the Green Revolution. According to research results about the behavior of tin in the copper smelting process [5,6,7,8,9,10,11], it is distributed to copper and slag and to gas because SnS and SnO are relatively volatile.

Results

Conclusion