Outokumpu Oyj

Heikki Siiril&auml;

Jens Nyberg

Juha J&auml;rvi

The present invention relates to an arrangement and method that help to reduce the build-up formed on the grate of a fluidized-bed furnace in the roasting of fine-grained material such as concentrate. The concentrate is fed into the roaster furnace from the wall of the furnace, and oxygen-containing gas is fed via gas jets under the grate in the bottom of the furnace in order to fluidize the concentrate and oxidize it during fluidization. Below the concentrate feed point, or feed grate, the oxygen content of the gas to be fed is raised compared with gas fed elsewhere using additional gas jets situated in the feed grate higher than the other jets. The extra jets of the feed grate are connected to their own gas distribution unit.

Arrangement and method for reducing build-up on a roasting furnace grate

The invention relates to a method of regulating a roasting furnace in fluidized bed roasting. Part of the roasting furnace grate is separated off into a separate grate section, known as the overflow grate, where the nozzles and the amount of roasting gas blown through them can be regulated independently of the main grate. It is advantageous to position the separately regulated grate in the section of the furnace where the overflow aperture is located.

Growing community of inventors

Parkki, Finland

Heikki Siirilä

Growing community of inventors

Parkki, Finland

Heikki Siiril&auml;

Heikki Siirilä