摘要 |
<p>The invention relates to a method for the concentration of the spent acid produced in connection with the scrubbing smelter or roaster gas. The hot gas produced is scrubbed first by dry and then by wet separation, and the scrubbed gas is conducted to the manufacture of a sulfurous end product. The spent acid formed is dilute, and its sulfuric acid content is increased by making use of the thermal capacity of the actual hot gas, which comes from dry separation. Thus, by making use of the thermal capacity of the gas created in the process, it is possible to replace, at least partly, the use of evaporators.</p> |