The sulfuric acid produced from gold concentrates with high arsenic and sulfur content has recently taken on a slight pink hue; I would appreciate some advice!
Thread Content
Our company is a gold smelting enterprise that deals with gold ores high in arsenic and sulfur; the raw materials contain 7% arsenic and 26% sulfur, as well as elements such as Cu, Fe, C, Sb, Pb, Zn, etc. Details on other elements are not available. The sulfur dioxide fumes generated after the roasting of raw materials are processed through concentration, drying, conversion, and absorption to produce 98% acid. Recently, 98 acid has taken on a slightly red color, quite faint. I need some advice.
The reddening of the sulfuric acid is likely due to poor dust removal or too high gas velocity, which causes the diluted acidic solution used for purification to be carried into the drying system. It has nothing to do with impurities in the raw materials.
It must be related to the components of the raw materials. A full elemental analysis of the finished acid may be related to the tin content.
The main issue is the poor dust collection efficiency; it is recommended to upgrade the dust collection system.
Reply 1# zxallan: It should be considered that the conversion gas contains NOx, which is transferred into sulfuric acid to form NO2- and NO3-, giving it a pink color.
Sulfuric Acid Industry 2010(4):16-20 Ways to Improve Product Quality in the Wet Process for Sulfuric Acid Production; the red color is caused by a complex formed between ferrous sulfate and nitric oxide