Forming Sulfur Filter Cake Recovered from Sulfiran Process for Agricultural Purposes

Hydrogen sulfide is an extremely toxic, corrosive and odorous gas, causing safety problems in its unaltered form. Different processes have been introduced to remove H2S from energy sources and recover it as elemental sulfur. Sulfiran process is an iron-redox based hydrogen sulfide removal technology and has been commercialized at RIPI. This process is an aqueous, low temperature sulfur recovery process, which produces micronized solid sulfur particles. The sulfur is normally filtered and washed to produce a filter cake, which is about 85% sulfur. Conducted studies indicate that obtained sulfur cake could be used in agriculture as a soil amendment and a plant nutrient after enrichment. However, evidence shows that the mechanical strength of such product after drying is low and will break down easily and its forming as granule gives it breakage resistance. This paper describes how this waste sulfur filter cake can be formulated by addition of proper additives such as 5% bentonite, 2% sodium lignosulfonate, 10% humic acid, and formed via wet granulation methods to be useful as a valuable product for agricultural purposes without being crushed. The product disintegrates rapidly on contact with soil moisture to provide fine sulfur powder.