Method of calcining and desulfurizing carbonaceous contiguous bed of agglomerates with particulate heat carriers

Claim 2

The method according to claim 2 in which the carbonaceous agglomerates are derived from sulfur-containing coal.

Claim 3

The method according to claim 3 in which the solid heat carrier is an H2S acceptor.

Claim 4

The method according to claim 4 in which a minor portion of the H2S acceptor is introduced into the preheating zone.

Claim 5

In the process of making calcined formcoke pellets from a sulfur-containing coal which includes the formation of the green pellets in a rotary tumbling kiln followed by calcination of the green pellets to produce formcoke suitable for use in an ore reduction furnace, the improvement in the calcination step of said process which comprises: a. establishing and maintaining a downwardly moving bed consisting essentially of a column of contiguous pellets, b. introducing hot finely divided H2S acceptor solids into said downwardly moving bed of pellets, a minor proportion of said acceptor solids being introduced into the top of said bed while the rest is introduced therebelow, c. showering said hot acceptor solids downwardly through the interstices of said downwardly moving bed of pellets at a velocity which is greater than that of said downwardly moving bed, d. passing a non-oxidizing gas upwardly through the downwardly moving streams of solids in countercurrent flow relationship thereto, e. regulating the temperature of the acceptor solids introduced into the downwardly moving bed of pellets and the relative velocities and amounts of the gas stream and the two streams of solids to preheat the pellets in the top portion of the downwardly moving bed to about 1,450* F. at a heating rate less than 10* F. per minute over the range of about 1,100* to about 1,450* F., and to maintain the temperature of the pellets above 1,400* F. in the lower portion of the bed until the desired calcination is effected, f. separating the acceptor solids from the calcined pellets, and regenerating the acceptor solids for recycle to the downwardly moving bed, and g. recovering the calcined pellets as formcoke suitable for use in ore reduction furnaces.

Claim 6

In the process of heat-treating heat-sensitive carbonaceous agglomerates, the improvement which comprises: a. establishing and maintaining a downwardly moving bed consisting essentially of a column of contiguous heat-sensitive carbonaceous agglomerates in a vertical retort, b. introducing a stream of hot heat carrier solids of finer size consist than the heat-sensitive solids into the downwardly moving bed of said heat-sensitive solids at a point intermediate the top and bottom of the column of downwardly moving heat-sensitive solids, c. showering said heat-carrier solids downwardly over the heat-sensitive solids and through the interstices thereof at a higher velocity than that of said hEat-sensitive solids, d. separating said heat-carrier solids from said heat-sensitive solids at the foot of said column of downwardly moving bed of solids, e. passing gas in heat exchange relation with the now hot separated heat-sensitive solids to effect cooling of said solids in a cooling zone, f. circulating the effluent gas from said cooling zone upwardly in countercurrent flow relationship to both downwardly moving streams of solids to assist in the transfer of heat from the heat-carrier solids to the heat-sensitive solids in a heating zone while at the same time being itself further elevated in temperature, and g. continuing the circulation of the gas beyond said point of introduction of heat-carrier solids upward through and in countercurrent flow relationship to the downwardly moving bed of heat-sensitive solids to effect preheating thereof in a preheating zone.