SU117648A1 - Reductive roasting of iron ores in a fluidized bed - Google Patents

Description

In the implementation of the known methods of reducing iron ores with gaseous reducing agents, only a small part of the heat spent is spent on the reduction processes, and a large part of it is spent on heating the ore. As a consequence, the consumption of gaseous fuel during the roasting of iron ores is too high.

The described method of reducing roasting of iron ores in a bipedal layer makes it possible to dryly increase the use of heat for reduction processes, significantly reduce the specific consumption of gaseous fuel, partially replacing it with solid. This is achieved by the fact that the combustion of solid fuel is produced in a mixture with ore, after which the heated ore in a mixture with cold fuel is reduced with a gaseous reducing agent.

Both fuel combustion and ore recovery are carried out in a fluidized bed.

The described method is carried out as follows.

The crushed ore mixed with solid reducing agent (fuel) is loaded from bunker 1 (see drawing) with feeder 2 to the upper part 3 of reactor A, where hot gases enter through lattice 4 from reactor B and lower part of reactor A. In contact with the ore and the fuel in the fluidized bed, these gases release their heat and go to the dust collection system 5, from where the dust returns to the reactor and the purified gases are removed from the system. After heating the charge through valve 6, it enters from the upper part of the reactor into its lower part 7, where the air supplied under the grill 8 is also introduced. Air, looking through the bale, look for a layer of ore and fuel, burns the latter.

A temperature of 650-800 ° C is maintained in the reactor.

The gases leaving the bed contain only carbon dioxide and water vapor, since carbon monoxide and hydrogen are used to reduce the iron oxide.

№ 117648

The heated ore through valve 9 enters the reactor B. In the same reactor, from the bunker 10, cold ore is fed by the feeder 11, which quickly mixes in the fluidized bed with the heated ore, lowering the bed temperature to 450-550 °. A gas, for example blast furnace or semi-water gas, is supplied to the grate 12. Gas can be fed into the ore layer by hot without much purification or cooling.

The recovered ore from reactor B through clanan 13 is poured into tank 14, where a stream of cold water is continuously fed, cooling and carrying the ore with it. Burned ore enters the magnetic enrichment.

To increase energy k. It is possible to load all the processed ore (without fuel) into the upper part of reactor A. In this case, the fuel is fed directly to its lower part. The ore, which is heated by gases, is partially supplied to the lower part of reactor A, and partially to reactor B.

The recovery of 1 ton of ore containing 60% iron oxide, 40% silica with a moisture content of 8%, consumes 50 kg of brown coal with a calorific value of 5000 kcal, 100 nm of gas with a calorific value of 900 cal / m and 350 nm of air.

Subject invention

The method of reductive roasting of iron ores in a fluidized bed, characterized in that, in order to reduce the consumption of solid gasified fuel, its combustion is carried out in a mixture with ore at 650-800 °, after which the heated ore is mixed in the ore reduction apparatus with ore the mixture is reduced by gaseous fuel at 450-550 °.