Stretford Sulfur Dewatering | Filter Press
DOFASCO INC., HAMILTON, ON, CANADA
Hamilton, Ontario, Canada
(1) VP-25-1 - 316SS
3-4 Ton/day Dry Sulfur Cake
Filtering, dewatering, washing of Sulfur from Stretford Process
The Dofasco Inc. facility processes coal into coke, in their #1 By-products area. The coke is used in the on-site, steel making process. While cooking the coal, many gases release from the coke ovens, which are used for fuel in the steel plant. The gas that comes off that cannot be used is Hydrogen Sulfide (H2S). This gas is sent through a reactor vessel with Stretford liquor that converts the gas into water and elemental Sulfur. The sulfur has to be removed from the Stretford liquor to recycle the costly, Stretford Process, chemicals. The Sulfur is a by-product as the liquor can be reuse many times, but the Sulfur is only valuable if it is filtered, washed and de-watered.
Previous to installation of the Verti-Press Filter, Dofasco Inc., utilized rotary vacuum drum filters and discharged the filter cake into an autoclave to dry the product. They did an extensive engineering study to determine what technologies would be available to replace their existing system.
They selected a system that would eliminate the recurring costs of running an autocalve and get the benefit of being able to rinse the Stretford liquor from the filtered Sulfur, to transform a hazardous waste disposal problem into a marketable product.
Since the Verti-Press Filter has been in operation at Dofasco, they have been producing Sulfur, which is rinsed of any impurities, non-hazardous, and is utilized as an additive in the steel making process. They are currently investigating the markets for selling the sulfur, i.e. agriculture, acid production, etc.