PROCESS FOR THE TREATMENT OF PARTICULATE MATTER BY FLUIDISATION, AND VESSEL WITH APPARATUS TO CARRY OUT THE TREATMENT

摘要

PURPOSE: A process and a vessel for reduction treating particulate matters by fluidisation is required not to generate sticking or fouling and to minimize the consumption of reduction treatment gas. CONSTITUTION: Particulate matter containing iron oxide, with a wide ranging grain size distribution and a relative large content of fines, preferably with a size being 50-150 micrometer of that of the largest particle, is used in the treatment. The empty pipe flow rate of the reducing gas in the fluidised bed (2) is kept smaller than, for example 0.25-0.75 Vmin/Dmax of the flow rate required for the fluidising of the larger particles of the particulate matter, the particulate matter is held and treated in a fluidised bed (2) with the reducing gas flowing from the bottom to the top, and all the larger particles thereof move to the top with the particulate and are released from the upper part of the fluidised bed (2). The vessel comprises a cylinder-type fluidized bed section (3) for supplying and distributing a reducing gas; a corn-type upper section (9) where the empty pipe flow rate of the reducing gas is decreased homogeneously and continuously; and a calming section (15). A gas pipe (17) is connected with a cyclone (21) for separating dust of the reducing gas, a recycling pipe of dust (22) from the cyclone (21) comes down to be connected into the fluidized bed (2), and the cyclone (20) represents a gas releasing by a reference signal (22).