RU2525881C1 - Device for extraction of elements from oxide ores - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: proposed device comprises plasmatron, feed channel, reaction channel, filter and powder collection vessel. Besides, this device comprises vessel to load the stock composed of the mix of coal nanopowders oxide ore. Nozzle serves to adjust stock feed rate from vessel into reaction channel arranged in feed channel. It has heat carrier channel surrounding said reaction channel and communicated with process channel including heat exchanger, thermal turbine and electric generator. Said process circuit can recover heat power as the difference between power released at carbon oxidation and power required for decomposition of oxides to electric power. Reaction channel expands in diameter from stock inlet and stock ignition by plasmatron to zone of the formation of oxide decomposition and carbon oxidation gases. Multisection filter is arranged downstream of said reaction channel.

EFFECT: extraction of powder elements, more complete usage of heat release at carbon oxidation and decomposition of oxides.

1 dwg, 3 tbl

Description

The invention relates to means for extracting elements from oxide ores.

Known devices for the extraction of iron oxides (RU 2244753, publ. 20.12.2003), aluminum (RU 2163268, publ. 02.20.2001) and silicon (RU 2165989, publ. 27.04.2001). In these devices, the mixture is prepared in the form of crushed ore powders, and the reducing agent is carbon-containing materials, including graphite electrodes. The disadvantage of these devices is the incomplete use of the oxygen component of the oxides, the need for input and heating of the oxidizing gas, mainly air. To equalize the energy distribution over the volume of the reduction reactor, the charge is moved in height (RU 2317342, publ. 07/27/2007), dual-zone reactors with cones diverging upward (RU 2247154, publ. 12/20/2003), lasers with periodic displacement of rays towards the zone elevated temperature (RU 2406766, publ. 20.12.2010), a melt of halides is introduced into the reaction zone, and to prevent carburization of the metal, the walls of the reactor are made of magnesite refractories (RU 2133291, publ. 07.20.1999). The disadvantages of the above devices are high energy consumption and the need for expensive reagents and materials.

The closest analogue is a device for plasma-chemical recovery of metals from a powder mixture (US 6821500 B2, publ. 23.11.2004). This device includes a supply container with ore powder, a plasma generator, a reaction channel, a filter, and a container for collecting the finished powder. The disadvantage of this device is its high energy intensity and the incomplete use of the energy of oxidation of carbon by oxygen oxides.

The objective of the invention is to reduce the energy intensity of the process of extracting elements from any oxide ores.

The technical result is a more complete use of the energy of carbon oxidation by oxygen oxides.

A device for extracting elements from oxide ores in the form of a powder contains a plasmatron, a feed channel, a reaction channel, a filter and a container for collecting powder. The device is also equipped with a capacity for loading raw materials in the form of a mixture of coal and oxide nanopowders in a stoichiometric ratio, an nozzle for regulating the feed rate of the raw materials from the tank into the reaction channel located in the feed channel, a coolant channel located with the coverage of the reaction channel and connected with the technological circuit comprising a heat exchanger, a heat turbine and an electric generator and configured to utilize thermal energy in the form of a difference between the energy released during oxidation and carbon, and the energy necessary for the decomposition of oxides into electrical energy. The reaction channel is made with expansion in diameter from the entrance to it of raw materials and ignition of raw materials by a plasma torch to the zone of formation of gases of decomposition of oxides and carbon oxidation. After the reaction channel, a multi-section filter is installed, which ensures the direction of the obtained powder into a container for collecting powder, and gases for disposal or into the atmosphere.

The technical result is achieved by using a mixture of a mixture of nanopowders of oxide ore and coal in a stoichiometric ratio for this type of reduction reaction. At the beginning of the process, for the decomposition of oxide into an element and oxygen, a plasmatron is used, the energy density of the “tongue” of which ensures complete decomposition of the oxides based on the feed rate of the charge, the difference in heat during the oxidation of carbon and during the decomposition of the oxide is utilized through a heat carrier, a heat turbine and an electric generator and is used in the future, both in equipment for the production of coal and ore nanopowders, and for heating industrial premises. The plasma torch is used only to “ignite” the process, then the necessary energy is extracted from the oxidative reaction. In addition, there remains excess heat and electricity, which are commercial products, additional to the finished powders of the elements. Table 1 shows the chemical reactions and heat balance for the main oxides that make up the oxide ores.

Table 1

For the case when “pure” oxide and “pure” carbon (demineralized coal) are used, Table 2 presents the carbon content, carbon dioxide yield and yield of marketable products: nanopowders of elements, thermal and electric energies per 1 ton of charge.

Table 2 Oxide C kg kWh Gcal Element, kg CO ₂ kg Al ₂ O ₃ 151 548 0.148 454 546 CaO 137 781 0.209 500 500 Cr ₂ O ₃ 81 374 0.105 701 299 CuO 82 653 0.176 699 301 FeO 96 554 0.151 649 351 Fe ₂ O ₃ 73 415 0.116 731 269 K ₂ O 63 510 0.140 769 231 MgO 190 1129 0.297 304 696 MnO one hundred 587 0.159 635 365 Na ₂ O 119 992 0.262 563 437 Nio 90 605 0.164 671 329 P ₂ O ₅ 151 1075 0.283 446 554 Pbo 12 42 0,021 956 44 SiO ₂ 197 478 0,132 278 722 TiO ₂ 146 348 0,099 466 534 Wo ₂ 28 32 0.018 899 101 Zno 81 638 0.172 703 297 ZrO ₂ 136 176 0,055 499 501 H ₂ O 268 1394 0.365 16 984

Pure oxides and demineralized coal can be prepared using a dry mineral processing unit (RU 2472593, publ. 01.20.2013). The preparation of nanopowders for the charge can be done using collider grinders with a fixed support shaft (RU 2397021, publ. 08/20/2010) using an air-dust flow synchronizer (RU 2450861, publ. 05/20/2012) and counter-rotation disks with bypass cavities (RU 2457033, published on July 27, 2012). Such crushers provide a destructive capacity of up to 250 kJ / kg, which is quite enough to break intermolecular bonds in any oxides and coals and to obtain initial powders for a mixture with a dispersion of 20–40 nm.

Almost more important and cost-effective is the direct use of oxide ores and commercial coal for the preparation of a charge. Table 3 shows the data on the output of marketable products when using coal from the Kuzbass basin with an ash content of 13%, apatite of Apatit OJSC, North-Onega bauxite, Krivorozhsky iron ore and red clay of the village. Aunts, Tatarstan.

Table 3 Oxide Apatite Bauxite Zhel. ore Clay The content of oxides in ores,% SiO ₂ 25.8 16,2 10.7 31.8 Al ₂ O ₃ 14.9 59.0 1,1 10.6 Fe ₂ O ₃ 5.1 11,4 86.6 3,5 CaO 25.6 1,2 od 25.3 MgO 0.9 0.3 0.2 1.4 P ₂ O ₅ 13.8 0.1 0.1 0 Na ₂ O 7.2 0.1 0 0.4 K ₂ O 3,5 0.2 0.1 1.9 TiO ₂ 1.8 3.4 0 0.5 MnO 0.2 0.1 0.1 0.1 H ₂ O 1,2 8.0 1,1 24.5 Coal content in 1 ton of pulp, kg coal 151 158 90 187 The output of commercial electric and thermal energy per 1 ton of pulp kWh 698 493 437 796 Gcal 0.187 0.159 0.122 0.213 Carbon dioxide output per 1 ton of pulp, kg CO ₂ 554 577 330 683 The outputs of the elements per 1 ton of pulp, kg Si 72 thirty thirty 88 Al 68 268 5,0 48 Fe 37 83 633 26 Sa 128 6.0 0.5 127 Mg 2.7 0.9 0.6 4.3 R 62 0.4 0.4 0 Na 41 0.6 0 2,3 TO 27 1,5 0.8 fifteen Ti 8.4 16 0 2,3 Mn 1.3 0.6 0.6 0.6

The invention is illustrated in the drawing. From the tank 1, the mixture using the nozzle 2 through the channel with a diameter of D ₁ enters the reaction channel 3. The feed rate of the mixture is determined by the ratio:

W is the feed rate of the charge, kg / s;

s is the cross-sectional area of the cross section of the feed channel, m ² ;

ΔP is the vacuum in the feed channel created by the nozzle 2, Pa;

ρ is the bulk density of the charge in the feed channel, kg / m ³ ;

k is the dimensionless aerodynamic coefficient (k≈0.3).

For example, for an inch channel, with a bulk density of the charge of 200 kg / m ³ and a vacuum created by a 0.2 bar nozzle, 1.86 kg / s (6.7 t / h) will be fed into the reaction volume. For guaranteed decomposition of such an amount of Fe ₂ O ₃ oxide, a kindling plasma torch with a tongue power of 4.2 MW is required.

The decomposition of oxide occurs during ignition in zone I of reaction channel 3 (the boundary of the zone in the drawing is indicated by a vertical dashed line), then, after the plasma torch is turned off, the oxide decomposition region is mixed into zone II. From the charge inlet to the end of the oxide decomposition zone, the diameter of the reaction zone increases from the value of D_one to the value of D₂ due to changes in the volume of solid pulp powder to a gaseous state of the products of decomposition and oxidation reactions. The reaction channel diameter D₂ covered by a channel of inner diameter D coolant chains 11. The length of the reaction channel and the coolant channel L is selected based on the heat balance of chemical reactions, the thermal conductivity of the walls of the reaction channel and the coolant channel, the heat capacity of the coolant and the feed rate of the pulp. Accordingly, the technical characteristics of the heat exchanger 8, turbine 9 and electric generator 10 are selected. The calculation data contained in tables 2 and 3 take the characteristics of Surgut GRES-2 according to the actual efficiency of using free heat of the reaction channel in the production of commercial heat and electric energy (33% for electricity and 10% of electricity for heat, which can actually be used for external consumers).

The gas-dust mixture from the reaction channel enters the interior of the multi-section filter 4. Sections with larger cells are located closer to the center, and sections with smaller sections are closer to the periphery. The technical characteristics of the filter allow passing gases discharged for disposal or into the atmosphere through hole 5, delaying and cooling the powders of elements that fall into the receiving tank of the finished metal powder 6 and are directed either through separation 7 to the separation (when using multicomponent oxide ores in the charge) or to the finished goods warehouse (when using pre-enriched oxides).

Using the equipment described above, as can be seen from the data in table 3, will bring a great economic effect, because revenues from the sale of nanopowders of elements, thermal and electric energies are tens, and in some ores, hundreds of times higher than the costs of raising and primary grinding of ores.

Claims (1)

A device for extracting elements from oxide ores in the form of a powder, containing a plasma torch, a feed channel, a reaction channel, a filter and a powder collecting container, characterized in that it is equipped with a container for loading raw materials in the form of a mixture of coal and oxide ore nanopowders in a stoichiometric ratio, a nozzle to control the feed rate from the tank to the reaction channel located in the feed channel, a coolant channel located with the coverage of the reaction channel and associated with the process circuit, containing a heat exchanger, a heat turbine and an electric generator and configured to utilize thermal energy in the form of the difference between the energy released during the oxidation of carbon and the energy necessary for the decomposition of oxides into electrical energy, while the reaction channel is made with an expansion in diameter from the input of raw materials and ignition of raw materials by the plasma torch to the zone of formation of gases of decomposition of oxides and oxidation of carbon, and after the reaction channel a multisection filter is installed that ensures the direction of the obtained Single in a container for collecting the powder and gases for recycling or to the atmosphere.