Direct reduction of iron ore

Claim 2

A process for reducing iron oxide as recited in claim 1 wherein said carbonaceous material is pulverized coal and said iron oxide is pulverized and wherein said steps of introducing said pulverized coal and iron oxide include conveying said pulverized coal and iron oxide into said reactor entrained in gas streams.

Claim 3

A process for reducing iron oxide as recited in claim 3 wherein said coal is pulverized such that the particles are primarily smaller than 200 mesh.

Claim 4

A process for reducing iron oxide as recited in claim 3 wherein said gas stream conveying said pulverized coal into said upper oxidizing zone comprises at least a portion of said oxygen-containing gas.

Claim 5

A process for reducing iron oxide as Recited in claim 5 wherein said portion of said oxygen-containing gas conveying said pulverized coal comprises air and wherein another portion of said oxygen-containing gas comprises relatively pure oxygen.

Claim 6

A process for reducing iron oxide as recited in claim 6 wherein said gas stream conveying said iron oxide into said reduction zone comprises relatively pure nitrogen.

Claim 7

A process for reducing iron oxide as recited in claim 7 wherein said gas stream conveying said pulverized coal into said reduction zone comprises air, said air comprising a portion of said additional oxygen-containing gas and wherein another portion of said additional oxygen-containing gas comprises relatively pure oxygen.

Claim 8

A process for reducing iron oxide as recited in claim 1 wherein said carbonaceous material, iron oxide and oxygen-containing as are introduced into said reactor from a plurality of locations circumferentially spaced around said reactor in each of said zones.

Claim 9

A process for reducing iron oxide as recited in claim 1 wherein said carbonaceous material, said oxygen-containing gas, said additional carbonaceous material, said additional oxygen-containing gas and said iron oxide are introduced into said reactor in a generally horizontal direction and generally tangential to an imaginary circle in said annular space.

Claim 10

The process for reducing iron oxide to form an iron product in a vertically extending generally cylindrical reactor including a central gas outlet duct extending downwardly into said reactor from the top thereof forming an annular space in said reactor around said duct and having an oxidizing zone adjacent the top of said annular space and a reducing zone spaced downwardly in said annular space from said oxidizing zone comprising the steps of: a. entraining pulverized coal in an airstream; b. introducing said pulverized coal in said airstream into said oxidizing zone of said reactor in a direction generally tangential to an imaginary circle in said annular space; c. introducing relatively pure oxygen into said oxidizing zone of said reactor also in a direction generally tangential to said circle, said pulverized coal and said oxygen and the oxygen in said air reacting in the absence of any significant amount of iron oxide to form an atmosphere having a CO2/CO ratio capable of reducing iron oxide and a temperature sufficiently high to maintain said iron product in a molten state, said atmosphere spiraling downwardly through said annular space; d. entraining pulverized iron ore in a gas stream; e. entraining additional pulverized coal in an airstream; f. introducing said pulverized iron ore in said gas stream and said additional pulverized coal in said airstream and additional relatively pure oxygen into said reducing zone of said reactor also in a direction generally tangential to said circle, said coal and said additional relatively pure oxygen and the oxygen in said air reacting to produce additional CO and CO2 to maintain said CO2/CO ratio and said temperature substantially throughout said reactor, said CO and said iron oxide reacting to produce said iron product; g. removing molten iron from the bottom of said reactor; h. removing the gaseous reaction products from said reactor upwardly through said central gas outlet duct; and i. conducting said gaseous reaction products directly to a boiler wherein said CO in said gaseous reaction products is burned and wherein heat is removed from said gaseous reaction products.

Claim 11

The process for reducing iron oxide as recited in claim 11 wherein said gas stream entraining said iron ore comprises nitrogen.

Claim 12

The process for reducing iron oxide as recited in claim 11 including introducing said pulverized coal and said relatively pure oxygen into said oxidizing zone from a plurality of locations circumferentially spaced around said reactor wherein each of said locations for introducing said relatively pure oxygen is directly adjaCent to one of said locations for introducing said pulverized coal.

Claim 13

The process for reducing iron oxide as recited in claim 13 including introducing said additional pulverized coal and said pulverized iron ore and said additional relatively pure oxygen into said reducing zone from a plurality of locations circumferentially spaced around said reactor wherein each of said locations for introducing said additional pulverized coal is directly adjacent to one of said locations for introducing pulverized iron ore and wherein each of said locations for introducing said additional relatively pure oxygen is directly adjacent to one of said locations for introducing additional pulverized coal.

Claim 14

The process for reducing iron oxide as recited in claim 14 wherein said additional pulverized coal is introduced upstream of said adjacent pulverized iron ore and said additional relatively pure oxygen is introduced upstream of said adjacent additional pulverized coal with respect to the direction of flow of the material around said annular space.

Claim 15

Apparatus for reducing iron oxide to form an iron product comprising: a. a vertically extending reactor vessel closed at the top and having a generally circular cross section, said reactor vessel including conduit means embedded therein for conducting H20 therethrough; b. a gas outlet duct having a generally circular cross section extending down into said reactor vessel through the closed top thereof thereby forming an annular space in said reactor vessel around said duct; c. iron product collecting means located at the bottom of said reactor vessel; d. a plurality of circumferentially spaced burners located adjacent the top of said reactor vessel adapted to feed pulverized coal and an oxygen-containing gas into said reactor vessel in a generally horizontal direction into said annular space said pulverized coal and oxygen-containing gas being introduced into said reactor generally tangential to an imaginary circle in said annular space; e. a plurality of circumferentially spaced nozzles located below said plurality of burners adapted to feed pulverized coal and an oxygen-containing gas and pulverized iron oxide into said reactor in a generally horizontal direction into said annular space said pulverized coal and oxygen-containing gas being introduced into said reactor generally tangential to said imaginary circle; and f. a steam generator mounted generally above said reactor vessel and adapted to receive the gases from said reactor vessel, wherein said gas outlet duct forms a portion of said steam generator, said steam generator including a combustion zone with means for introducing combustion air to react with CO gas in the gas flowing from said reactor vessel into said steam generator.

Claim 16

Apparatus for reducing iron oxide as recited in claim 16 wherein each of said circumferentially spaced nozzles include means for introducing said pulverized iron ore entrained in a gas stream and separate means for introducing said pulverized coal directly adjacent said pulverized iron oxide and separate means for introducing relatively pure oxygen directly adjacent said pulverized coal.

Claim 17

Apparatus for reducing iron oxide as recited in claim 16 wherein said conduit means for conducting cooling H20 through said reactor vessel is operatively connected to the steam generating circuit of said steam generator.