Chapter 14 - Capture and Fixation of Sulfur

Abstract

This chapter discusses the manufacturing of sulfuric acid from smelter gases, offgases from smelting and converting, and future developments in sulfur capture. It describes that most copper is extracted from sulfide minerals so that sulfur, in some form, is a byproduct of most copper extraction processes. The usual byproduct is sulfuric acid, made from sulfur dioxide that is produced during smelting and converting. The production of sulfuric acid entails the cleaning and drying of the furnace gases, catalytically oxidizing sulfuric dioxide to sulfur trioxide, and absorbing the resulting sulfur trioxide into a 98% sulfuric acid solution. The recovery of sulfur dioxide can be increased by scrubbing the acid plant tail gas with basic solutions. Some modern smelting processes produce extra-strong sulfur dioxide gases that tend to overheat during sulfur dioxide to sulfur trioxide oxidation, causing catalyst degradation and inefficient conversion. This will lead to the development of catalysts that have low ignition temperatures and high degradation temperatures. The use of oxygen-enriched air or industrial oxygen for sulfur dioxide to sulfur trioxide conversion would minimize the size of the acid plant and the amount of gas being blown.