RU2476035C1 - Reducing method of metals from oxides - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: reducing method of metals from oxides refers to reducing technologies of metals from non-organic oxides, at which preparation of homogeneous mixture is performed from ultradisperse powders of metal oxide and carbon, supply of prepared mixture under pressure to high-temperature zone in the well, which is formed with plasmatron jet, decomposition of metal oxide with formation of carbon dioxide that is removed through upper tuyeres of the well, and finished product is removed in the form of ultradisperse metal powder through tap holes in lower part of the well.

EFFECT: method allows reducing power consumption at reduction of metals from oxides and ensures the reduction of content of impurities in finished product at direct extraction of metals from oxides during continuous process.

Description

The invention relates to technologies for the recovery of metals from inorganic oxides.

For recovery, it is necessary to destroy the energy of intramolecular bonds. Quantitatively, such relationships have been well studied and are reference values [1]. In practice, the most common reduction technology is carbon, when the energy released during the oxidation of carbon (395 kJ / mol) destroys the intramolecular bonds in molecular particles located in the “combustion” zone of carbon. In particular, for the destruction of intramolecular bonds in magnetite (FeO · Fe ₂ O ₃ ) it is required to expend energy in the amount of 1117 kJ / mol.

To improve production characteristics, the reaction part of blast furnaces is lined with carbon material [2], combined blasting with fuel additives [3], oxygen and natural gas supply through additional tuyeres [4], a gas generator connected by a channel to the shaft in its lower part [5] , an electric furnace using hollow and solid carbon electrodes [6], a plasma torch with electrodes made in the form of graphite tubes coaxially arranged with a gap between them [7], oxidative plasma iron oxide melting th jet of a mixture of oxygen and natural gas. In addition, natural gas is supplied behind the nozzle section of the plasma torch, during the conversion of which hydrogen and pyrocarbon are formed [8].

The closest analogue is the technology of plasma-chemical reduction of metals, described in [9]. The installation includes a loading hopper with metal oxide, a zone of high-temperature decomposition of raw materials by a plasma torch jet (reactor), precipitation chambers and filters equipped with a shaking device for unloading the reduced metal powder. The disadvantage of this technology is the high energy intensity of the process, which requires constant operation of the plasma torch, and the plasma-forming jet must be reducing, for example, hydrogen.

The objective of the invention is to reduce energy consumption during the recovery of metals from oxides.

The technical result of the invention is the ability to recover metals from oxides using a cheap oxidizing agent - finely divided coal powder, mixed in the required stoichiometric ratio with finely divided metal oxide powder.

The technical result is achieved in that the mixture is prepared in the form of a homogeneous mixture of ultrafine powders of metal oxide with carbon and is fed into the high temperature zone of the oxide melt (decomposition). The oxygen released from the oxides binds to carbon, and the resulting carbon dioxide is then removed from the process through a filter. The plasma torch “ignites” the process, the metal oxide decomposes and the released oxygen oxidizes carbon (finely dispersed carbon powder) and subsequently the required temperature is maintained by the generated heat (4900 kJ / kg).

The invention is illustrated by the figure, in which 1 is a container containing a homogeneous mixture of ultrafine oxide and carbon powders in the stoichiometric ratio necessary for a given oxide, 2 is a plasmatron initiating a high-temperature zone in channel 3. Behind this channel is a container 4 with filter 5 and nozzle 6. Metal powder is discharged through channel 7.

The technology is implemented as follows.

Under the action of the vacuum created by the nozzle 6, the mixture

fine powders of metal oxide and coal enters the channel 3, the plasma torch 2 “ignites” the oxide and subsequently the temperature in the channel is maintained by oxidation of carbon. Carbon dioxide through the filter 5 is removed from the process, and metal powder accumulates in the hopper 4 and is discharged through the channel 7.

Information sources

1. Constants of inorganic substances: reference book / R.A. Lidin, L.L. Andreeva, V.A. Molochko. - M.: Bustard, 2008.

2. RU No. 2133291, publ. 07/20/1999.

3. RU No. 2086657, publ. 08/10/1997.

4. US No. 5100313, publ. 03/31/1992.

5. RU No. 2095710, publ. 11/10/1997.

6. RU No. 2121518, publ. 11/10/1998.

7. RU No. 1387423, publ. 03/10/1997.

8. RU No. 2371490, publ. 10/27/2009.

9. RU No. 2238824, publ. 10/27/2004 (Prototype).

Claims (1)

A method of recovering metals from oxides, comprising preparing a homogeneous mixture of ultrafine metal oxide powder and fine coal powder, feeding the prepared mixture under pressure into a high-temperature zone formed by a plasma torch jet, the nozzle of which is angled into a channel adjacent to the shaft, subsequent decomposition of metal oxide with the formation molten metal oxide and carbon dioxide, which is fed into the upper part of the aforementioned mine and removed from it through lances to release gas, and the finished product t in the form of reduced metal is removed through the notches in the lower part of the mine.

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