Desulfurization of phosphogypsum

A process for producing sulfur and/or sulfur dioxide from phosphogypsum comprising the steps of

• forming a mixture of fine high-sulfur content coal and fine phosphogypsum so that the mixture includes at least about 3 to 8 parts by weight fixed carbon content for every 92 to 97 parts by weight gypsum content,
• balling the mixture to form pellets having a diameter of about 13 mm,
• charging the pellets to a circular travelling grate to form a layer of pellets on the grate,
• moving the grate and layer of pellets successively through drying, firing, post firing and cooling zones in a sealed hood arrangement,
• burning high sulfur content fuel in a fixed bed gas producer to produce a hot raw low BTU gas,
• feeding the hot gas to the firing zone to heat the pellets to about 1200.degree. C. to produce a product gas containing sulfur or sulfur dioxide or both sulfur and sulfur dioxide from the pellets,
• removing the product gas from the firing zone, and
• passing a portion of the product gas through the charge in the post firing zone.