Re: Please explain us the method of removing free sulfur from carbon black

In reading about carbon black, there seems to be several processes for 
producing carbon. Many of these processes use differing feedstocks to 
produce the desired quality of carbon black. The quality seems also 
dependent on the "art" of its production. The CB from acetylene, furfural 
extracts, or heavy residuum differ in their properties. 

From my experience, sulfur in the "free" state, is extremely small. Sulfur 
in hydrocarbon feeds consist mainly of organically bound sulfur, 
mercaptans, sulfides, and thiophenes. The sweetening of hydrocarbon 
streams deals with these organic sulfur compounds using caustics and 
amines. 

During processing, the inorganic sulfur compounds generated are mainly 
hydrogen sulfide, carbonyl sulfide, and sulfoxides. Sulfur recovery plants 
produce elemental sulfur from these gas streams.

From your question, it's difficult to determine the source of the carbon 
black, the nature of the process CB is being used, and the quantities of 
CB you're processing. These will play a major role in determining a system 
suitable for your needs.