JPH03183709A - Smelting reduction apparatus - Google Patents

Abstract

PURPOSE:To reduce powdery ore with good yield by executing dust collecting treatment to reducing waste gas in a smelting reduction furnace with a dust collecting apparatus, supplying this into a pre-reduction furnace, forming fluidized bed and executing pre- reduction to raw material powdery ore at the time of refining the powdery ore into a metal with the pre-reduction furnace and the smelting reduction furnace. CONSTITUTION:In the powdery ore refining apparatus composed of the smelting reduction furnace 1 using the powdery ore as the raw material and the pre-reduction furnace 11 for the powdery ore with CO-containing reducing high temp. waste gas 7 generated from the above reduction furnace 1, after recovering the dust of the powdery ore, a reducing agent, etc., contained in the waste gas by passing the waste gas 7 through a porous filter 23, the high temp. reducing gas is blown up into the pre-reduction furnace 11 through a gas dispersion plate 14, and by forming the fluidized bed 13 for the powdery ore, the pre-refining is executed to the powdery ore. This pre-refined material is supplied into the smelting reduction furnace 1 and also by using the dust recovered with the dust collecting apparatus in the smelting reduction furnace, the powdery ore is reduced into the metal with good yield for the raw material and excellent heat efficiency.

Description

[Detailed description of the invention]

[Industrial f11 application field 1 The present invention relates to a smelting reduction furnace and the gas generated from the smelting reduction furnace to f1
The present invention relates to a metal oxide melting and reduction apparatus comprising a fluidized bed pre-reduction furnace used in the present invention.

[Conventional Technology J] In recent years, ore raw materials containing iron oxide or various gold rim compounds have become less lumpy ores and more powdery or granular ores, and this trend is expected to become more pronounced in the future. Ru. In view of this current situation, technology has been developed to directly use granular ore for smelting. This is a method of directly producing molten metal. This method is a method for pre-reducing metal oxide-containing ores in a fluidized bed format using high-temperature exhaust gas from a smelting reduction furnace as a source of the reducing agent and heat necessary for pre-reducing ores. According to this method, the granular ore can be used directly as a raw material without being agglomerated, so it is possible to produce molten metal at low cost. FIG. 3 shows an example of a smelting reduction apparatus comprising a smelting reduction furnace and a fluidized bed preliminary reduction furnace that utilizes the gas generated by the smelting reduction furnace. The smelting reduction furnace l is vertical and equipped with a carbon material inlet 2 at the upper end to form a carbon material packed bed 3 in the furnace, and a tuyere 4 for injecting oxygen and semi-reduced powder ore into the bottom of the furnace. is equipped with a molten metal reservoir 5 and its discharge port 6. The generated gas 7 of the smelting reduction furnace 1 is led through a cyclone 8 to a fluidized bed preliminary reduction furnace ti, where it fluidizes and reduces the powdered ore supplied from the stone hopper 12. The high-temperature exhaust gas 7 generated from the melting reduction furnace 1 functions as a reducing gas and a fluidizing gas in the fluidized bed preliminary reduction furnace 1. By introducing this reducing gas into the fluidized bed preliminary reduction furnace 11, the powdery ore is fluidized to form a fluidized bed 13 and fluidized and reduced. [Problems to be Solved by the Invention] In such a smelting reduction apparatus, the cyclone 8 collects dust consisting of fine ore, graphite, etc. discharged from the smelting reduction furnace 1 together with the exhaust gas. In conventional one-stage or multi-stage cyclones, gas with low collection efficiency and high dust concentration was supplied to the fluidized bed pre-reduction furnace 11. Therefore, there was a problem that the distribution plate 14 at the entrance of the fluidized bed was clogged. The present invention provides a metal oxide smelting reduction apparatus comprising such a smelting reduction furnace and a fluidized bed pre-reduction furnace that utilizes the gas generated from the smelting reduction furnace. Instead of the conventional cyclone, we replaced the collection device installed in the airflow with a dust collection device with a simple and long-life Ill structure that has high dust collection efficiency and has a long service life. γ that can be supplied to the reduction furnace
The purpose of the present invention is to provide a refractory reduction device. [Means for Solving the Problems J] The present invention provides a metal oxide smelting reduction apparatus consisting of a smelting reduction furnace and a fluidized bed pre-reduction furnace that utilizes gas generated from the smelting reduction furnace. This melting reduction apparatus is characterized in that a dust collection device made of a porous filter is provided in the gas line between the layer and the preliminary reduction furnace. [Function] A dust collection device consisting of a porous filter tube is installed in the gas line between the smelting reduction furnace and the fluidized bed pre-reduction furnace, so clean gas from which dust has been removed is introduced into the fluidized bed pre-reduction furnace. be done. The filter is divided into at least two series to form a gas immersion path, and each series is occasionally backwashed to prevent the filter from clogging. In this way, since clean gas is supplied, clogging of the distribution plate of the fluidized bed pre-reduction furnace can be prevented, and long-term continuous stable operation has become possible. [Example] As shown in FIG. 1, a smelting reduction furnace 1 and a fluidized bed pre-reduction furnace 11 that forms a fluidized bed 13 using the generated gas 7 of the smelting reduction furnace 1 to pre-reduce fine ore. In a metal oxide melting reduction device consisting of
A dust collection device 21 equipped with a porous filter 23 was provided in place of the cyclone. As shown in FIG. 2, the dust collection device 21 has an outer diameter of 250 mmφ and a length L=2000 mm inside the casing 22.
50 porous filter tubes 23 and 25 pieces each
They are divided into series, and the outlet pipe 26 corresponds to this series. The filter tube 23 uses a hollow cylindrical ceramic filter through which gas is filtered from the inner diameter to the outer diameter, and dust made of fine ore adheres to the inner diameter of the filter tube 23. Two series of filters or more: 4 L+ -5 printings 1; Yang Hiroshi 1. Removes Red 1 fraud from τi Sunpu Damata. This dust accumulates on the bottom 24 of the dust collector 21 as collected dust 25, and is again blown into the melting reduction furnace through the tuyere. A smelting reduction furnace exhaust gas of 300 ONd/H at a temperature of 1050°C was generated and used as a reducing gas in the fluidized bed pre-reduction furnace. Concentration in smelting reduction furnace exhaust gas is 50 to 150 kg/Nrr
? With the conventional cyclone method, the collection efficiency of dust from the generated gas was 90.5%, but with the present invention, the collection efficiency was 90.5%.
It became 9.99%. [Effects of the Invention] According to the present invention, there is no clogging of the fluidized bed dispersion plate, and long-term continuous operation is possible.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of an embodiment of the present invention, Fig. 2 is (a) a longitudinal sectional view, (b) a view taken along the line B-B, and Fig. 3 is a molten ore collecting device of the embodiment. This is an overall flow sheet of the reduction device. l... Melting reduction furnace 7... Generated gas 8... Cyclone 11... Fluidized bed preliminary reduction furnace 13...-Fluidized bed 14... Gas distribution plate 21-... Fine ore collection device 22 ...Casing 23...Porous filter 24...Lower casing 25...Collected dust 26...Outlet pipe Applicant Kawasaki representative

Claims (1)

[Claims] 1. In a metal oxide smelting reduction apparatus consisting of a smelting reduction furnace and a fluidized bed pre-reduction furnace that utilizes gas generated from the smelting reduction furnace, a gas line between the smelting reduction furnace and the fluidized bed pre-reduction furnace is provided. , a melting and reducing apparatus characterized by comprising a dust collection device made of a porous filter.