Method of treating coal refuse

Claim 1

A METHOD OF TREATING RELATIVELY LOW HEATING VALUE COAL REFUSE CONTAINING A HIGH ASH CONTENT AND SULFUR IN THE FORM OF PYRITES COMPRISING THE STEPS OF: MIXING THE COAL REFUSE WITH LIMESTONE IN AN AMOUNT OF AT LEAST ABOUT 3 POUNDS OF LIMESTONE PER POUND OF SULFUR CONTAINED IN SAID COAL REFUSE, AGGLOMERATING THE COAL REFUSE-LIMESTONE MIXTURE INTO PELLETS, HEATING THE COAL REFUSE-LIMESTONE PELLETS TO A TEMPERATURE IN THE RANGE OF FROM ABOUT 1,600*F TO ABOUT 2,800*F WITHOUT MELTING SAID PELLETS SO THAT PYRITES CONTAINED IN THE COAL REFUSE REACT WITH LIME TO FORM METALLIC OXIDE COMPOUNDS AND CALCIUM SULFIDE THEREBY CONVERTING THE PELLETS TO MIXTURES OF CALCIUM SULFIDE, METALLIC OXIDE COMPOUNDS AND ASH, AND REACTING THE CALCIUM SULFIDE-METALLIC OXIDE-ASH PELLETS WITH CARBON DIOXIDE AND WATER TO FORM A COHERENT CALCIUM CARBONATE BONDED PELLET PRODUCT AND HYDROGEN SULFIDE.

Claim 2

A METHOD OF TREATING RELATIVELY LOW HEATING VALUE COAL REFUSE CONTAINING A HIGH ASH CONTENT AND SULFUR IN THE FORM OF PYRITES COMPRISING THE STEPS OF: MIXING THE COAL REFUSE WITH LIMESTONE IN AN AMOUNT OF AT LEAST ABOUT 3 POUNDS OF LIMESTONE PER POUND OF SULFUR CONTAINED IN SAID COAL REFUSE, AGGLOMERATING THE COAL REFUSE-LIMESTONE MIXTURE INTO PELLETS, HEATING THE COAL REFUSE-LIMESTONE PELLETS TO A TEMPERATURE IN THE RANGE OF FROM ABOUT 1,600*F TO ABOUT 2,800*F WITHOUT MELTING SAID PELLETS SO THAT PYRITES CONTAINED IN THE COAL REFUSE REACT WITH LIME TO FORM METALLIC OXIDE COMPOUNDS AND CALCIUM SULFIDE THEREBY CONVERTING THE PELLETS TO MIXTURES OF CALCIUM SULFIDE, METALLIC OXIDE COMPOUNDS AND ASH, AND REACTING THE CALCIUM SULFIDE-METALLIC OXIDE-ASH PELLETS WITH CARBON DIOXIDE AND WATER TO FORM A COHERENT CALCIUM CARBONATE BONDED PELLET PRODUCT AND HYDROGEN SULFIDE.

Claim 6

A method of treating relatively low heating value coal refuse containing sulfur in the form of pyrites and a high ash content, comprising the steps of: particulating the coal refuse to a particle size of from about one-half inch in diameter to about 100 mesh (U.S. Sieve Series); mixing the particulated coal refuse with crushed limestone in an amount of at least about 3 pounds of limestone per pound of sulfur contained in said coal refuse; pelletizing the mixture of coal refuse and limestone; heating the coal refuse-limestone pellets to a temperature in the range of from about 1,600* to about 2,800*F without melting said pellets so that the limestone and pyrites contained therein react to form metallic oxide compounds and calcium sulfide; cooling the resulting calcium sulfide-metallic oxide-ash pellets to a temperature of about 200*F; and reacting the resulting cooled pellets with carbon dioxide in an amount of at least about 1.5 pounds of carbon dioxide per pound of sulfur contained in said coal refuse and water in an amount of at least about 0.6 pounds of water per pound of sulfur contained in said coal refuse to form a pelletized calcium carbonate bonded product and hydrogen sulfide.

Claim 7

A method of treating relatively low heating value coal refuse containing sulfur in the form of pyrites and a high ash content, comprising the steps of: particulating the coal refuse to a particle size of from about one-half inch in diameter to about 100 mesh (U.S. Sieve Series); mixing the particulated coal refuse with crushed limestone in an amount of at least about 3 pounds of limestone per pound of sulfur contained in said coal refuse; pelletizing the mixture of coal refuse and limestone; heating the coal refuse-limestone pellets to a temperature in the range of from about 1,600* to about 2,800*F without melting said pellets so that the limestone and pyrites contained therein react to form metallic oxide compounds and calcium sulfide; cooling the resulting calcium sulfide-metallic oxide-ash pellets to a temperature of about 200*F; and reacting the resulting cooled pellets with carbon dioxide in an amount of at least about 1.5 pounds of carbon dioxide per pound of sulfur contained in said coal refuse and water in an amount of at least about 0.6 pounds of water per pound of sulfur contained in said coal refuse to form a pelletized calcium carbonate bonded product and hydrogen sulfide.

Claim 9

A method of treating relatively low heating value coal refuse containing sulfur in the form of pyrites and a high ash content comprising the steps of: particulating the coal refuse to a particle size of from about one-half inch in diameter to about 100 mesh (U.S. Sieve Series); mixing the particulated coal refuse with crushed limestone in an amount of at least about 3 pounds limestone Per pound of sulfur contained in said coal refuse; pelletizing the mixture of coal refuse and limestone; heating the coal refuse-limestone pellets to a temperature in the range of from about 1,600* to about 2,800*F without melting said pellets so that the limestone and pyrites contained therein react to form metallic oxide compounds and calcium sulfide; reacting the calcium sulfide-metallic oxide-ash pellets with steam in an amount of at least about 0.6 pounds of steam per pound of sulfur contained in the coal refuse and air in an amount of about 2 pounds of air per pound of sulfur contained in said coal refuse to form calcium oxide-metallic oxide-ash pellets and elemental sulfur vapor; and contacting the calcium oxide-metallic oxide-ash pellets with carbon dioxide to form a pelletized calcium carbonate bonded product.

Claim 10

A method of treating relatively low heating value coal refuse containing sulfur in the form of pyrites and a high ash content comprising the steps of: particulating the coal refuse to a particle size of from about one-half inch in diameter to about 100 mesh (U.S. Sieve Series); mixing the particulated coal refuse with crushed limestone in an amount of at least about 3 pounds limestone Per pound of sulfur contained in said coal refuse; pelletizing the mixture of coal refuse and limestone; heating the coal refuse-limestone pellets to a temperature in the range of from about 1,600* to about 2,800*F without melting said pellets so that the limestone and pyrites contained therein react to form metallic oxide compounds and calcium sulfide; reacting the calcium sulfide-metallic oxide-ash pellets with steam in an amount of at least about 0.6 pounds of steam per pound of sulfur contained in the coal refuse and air in an amount of about 2 pounds of air per pound of sulfur contained in said coal refuse to form calcium oxide-metallic oxide-ash pellets and elemental sulfur vapor; and contacting the calcium oxide-metallic oxide-ash pellets with carbon dioxide to form a pelletized calcium carbonate bonded product.