RU2399003C2 - Melting furnace - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: furnace consists of case with installed therein melting section equipped with facility for charge supply and burner and electro-thermal section divided from melting section with partition not reaching hearth; also melting section is equipped with electrodes, electric holders, devices for metal and slag tapping and with gas duct. A lower edge of the partition is positioned above the level of the slag tapping device thereby forming a gas-overflow port of alternate cross section with the level of melt. The metal tapping device is equipped with a well communicated with an overflow zone of the partition via a channel. Section of the port is chosen according to specified ratio of furnace width to inter-axis distance between electrodes. The charge supply facility has a chute superposed on a stepped hearth with incline to a partition side.

EFFECT: treatment of lead concentrate of current production of raised humidity (up to 4-6%) ensuring additional recovery of metal from volatile dust-gas components by transmitting them through electro-thermal section; reduced exhaust of lead containing dust.

1 dwg

Description

The field of technology. The invention relates to the field of non-ferrous metallurgy and, in particular, to devices for smelting lead concentrate obtained from scrap waste automobile batteries.

The level of technology. Known short-drum furnace for torch melting battery scrap. The disadvantage of the furnace is a large yield of dusts (8-10%) and slags (about 20%), with a lead content of ~ 15%, in addition, low lining resistance and low productivity (see Khudyakov I.F. et al. “Technology of secondary non-ferrous metals. ”M., Metallurgy, 1981, 80 pp.)

Known electrothermal furnace for melting battery scrap, the advantages of the furnace: ease of regulation, low slag yield (3-5%), with soda. Pb 1-4% and dust - about 4% (see Khudyakov I.F. et al. “Technology of secondary non-ferrous metals.” M., Metallurgy, 1981, 80 pp.) However, with increased humidity of the starting material, there is a need drying, which leads to increased costs for the construction and operation of the furnace complex. In addition, in the electrothermal zone, the arch around the electrodes quickly burns out and needs to be repaired, and bypassing the electrodes and releasing the metal are laborious operations; for example, a lead lead should be carefully sealed after each metal release and burned each time before release, this is due to increased labor costs (time, materials, energy, etc.).

A known furnace for processing battery scrap according to the Kivcet (Kepal-ZhV) method, comprising a hearth, a body with a melting section located therein with a charge-oxygen burner and an electrothermal section separated from the melting section by a water-cooled partition that does not reach the bottom (and immersed in the melt ), with tap holes for the production of slag and metal, an opening for the removal of sublimates and process gases and electrodes, "Metallurgical processing of secondary lead raw materials" / Ed. A.V. Tarasova. - M .: Gintsvetmet, 2003 .-- 224 p.

The main disadvantage of the known design is the possibility of increased dust removal and, in particular, due to particles of boundary size that have not passed into the liquid metal phase in the flare zone. In addition, there is instability of the overflow (under the partition), often blocked by hearth floorings, and the need to dry the starting material (up to 1%).

The closest analogue to the claimed invention is a unit for processing copper-zinc and lead-zinc materials, including a hearth, a housing with a melting section located therein with a charge-oxygen burner, a tap hole for the discharge of a liquid metal bottom phase, an opening for the removal of process gases and dust, and electrothermal section, separated from the melting section by a water-cooled partition that does not reach the bottom, with a notch for the release of slag, an opening for the removal of sublimates and process gases and electric cathodes immersed in a slag melt and connected to a current source, characterized in that the melting section additionally contains electrodes mounted on a hearth and connected to one pole of the current source, while the electrodes placed in the electrothermal section are connected to the opposite pole of the current source. Patent RU No. 2236659 C1, F27B 3/08, C22B 15/00, C22B 19/00, C22B 13/00, Author (s): Nus G.S. (RU); Tarasov A.V. (RU); Paretsky V.M. (RU).

The main disadvantage of the known design, in relation to the smelting of lead (Pb) concentrate obtained from scrap automobile batteries, is the need for drying of the starting material and the possibility of large dust removal (through the hole for removing process gases and dust from the flare zone to the filter). The re-melting of circulating dusts is associated with additional costs for re-heating and a decrease in productivity, etc. In addition, in the electrothermal section, the arch around the electrodes quickly burns out and requires repair, and bypassing the electrodes and releasing the metal are labor-intensive operations.

The purpose of the invention. Improving the ecology and safety of the scrap preparation and melting system with the ability to load granules of the current production with humidity up to 4-6%, while increasing the reliability of the equipment.

SUMMARY OF THE INVENTION 1. The furnace allows you to process lead concentrate of current production - high humidity (up to 4-6%), with the receipt (in the flare section) of intermediate products, non-explosive and fire hazardous for further loading and smelting in the electrothermal section. 2. There is the possibility of additional extraction of metal from the "volatile", dust and gas components of the flare smelting during their passage into the electrothermal section, while the yield of lead-containing dusts is reduced.

This goal is achieved by the fact that the melting and electrothermal sections of the furnace are separated by a partition that forms (with a melt level) a gas transfer window of variable cross section, and the metal exhaust device is equipped with a well connected by a channel to the lower transfer zone of the partition; at the same time, changing the window cross section allows you to choose the optimal mode in accordance with a given ratio of the width of the furnace to the center distance between the electrodes;

Besides:

- the charge supply is equipped with a groove superimposed on the stepped hearth of the melting section, with an inclination towards the partition;

- part of the arch around the electrodes is coffered, and the electrode holders are made water-cooled and with pneumatic extraction.

The relationship of these elements is manifested and implemented as follows.

1. Usually, when moistened raw materials are loaded into an electrothermal furnace, there is a danger of the formation of explosive slopes, when they are turned over, the wet mixture comes into contact with a liquid bath and an explosion occurs - “cotton”;

- in the inventive furnace, the charge is fed to the "gutter 17, superimposed on a stepped hearth 18 with an inclination towards the partition b".

This relative position of the elements of the melting section 2 contributes to the safe melting and breaking (on the steps) of the moistened material and the inclined displacement of the softened, during flare melting, charge to the partition 6, into the main bath of the furnace; and the proximity of the channel 16 enhances the turbulization and mobility of the flows in the area of the partition 6. Thus, the formation of slopes and "pops" is excluded.

2. There is the possibility of additional extraction of metal from the "volatile", dust and gas components of the flare smelting due to:

- interference of the fused particles into the surface of the liquid bath in the zone of the gas transfer window of variable cross section (formed by a partition separating the melting and electrothermal sections of the furnace);

- as well as during the melting of more refractory components during the subsequent passage of the dust and gas stream through the high-temperature electrothermal section.

At the same time, changing the window cross section due to raising or lowering the partition allows one to influence the dynamics of processes in the - transfer zone and the electrothermal section of the furnace and select the optimal mode in accordance with the given ratio of the furnace width to the center distance between the electrodes (or the length of the furnace);

4. - "the device for the release of metal is equipped with a well connected by a channel to the overflow zone of the partition";

- the structural implementation of these elements is used for accelerated and / or continuous release of metal through the upper part of the well 15 (see also figure 2), i.e. no need to burn lead lead in each release of lead; however, if necessary (for example, when emptying the furnace, then part of the flow in channel 16 (from well 15) has the opposite direction) this possibility is available - in the lower part of the well 15 connected to channel 16.

5. - the need to eliminate the "rapid burnout of the arch around the electrodes ..." and the "laborious operations of bypassing the electrodes" is important in this design of the furnace, given the possibility of intensification of heat flows (when reflecting the inclined dust and gas stream from the surface of the liquid bath of the transfer zone) and is achieved by that "part of the arch around the electrodes is coffered, and the electrode holders are made water-cooled and with pneumatic extraction."

Description of the device. The drawing shows the inventive device, comprising a housing 1 and a melting section 2 located therein (with a charge feeding device 3 and a burner 4) and an electrothermal section 5 separated from the melting section by a partition 6, a vault 7, a hearth 8, with electrodes 9, electrode holders 10 , devices for the release of metal 11, slag 12 and a gas duct 13, a gas transfer window of variable cross-section 14, a well 15, a channel 16, a lower transfer zone 14 / A, an opening 19; groove 17, stepped hearth 18.

The principle of operation: the source material is fed into the flare zone 2, to the gutter 17, the resulting liquid metal fraction flows down a stepped hearth 18 into the partition zone 6.

The remaining part - more refractory and other solid fragments, as well as small (submicron-sized) particles are displaced along the stepped surface of the inclined hearth 18 into the zone of the partition 6. In this case, there is the possibility of additional extraction of metal due to:

1. interference of dust and gas particles, for example, partially fused (containing about 55-70% lead) in the surface layers of the liquid bath of the transfer zone;

2. subsequent melting of more refractory dust and gas particles in the high-temperature (and chemically active) electrothermal part of the furnace 5, after reflection of the inclined dust and gas stream from the surface of the liquid bath of the transfer zone (through window 14).

The electrothermal section 5 is heated by means of electrodes 9, the slag is removed through a slag discharge device 12, the process gases and dust are removed through a gas duct 13, and the metallized bottom phase (with the possibility of an accelerated, i.e., not requiring normal time, burning lead lead , and / or continuous release of metal) - through the opening 19, channel 16, well 15 and further into the drain trough 11. The well 15 is connected by channel 16 to the lower transfer zone 14 / A of the partition 6. In operation, the bottom layers of the melt are quite mobile. The increased mobility of the upper layers of the liquid bath, in the area of the window 14, is facilitated by a heated, directed dust and gas flow (from the melting section 2). Moreover, changing the cross section of the window 14 allows you to choose the optimal mode in accordance with a given ratio of the width of the furnace 5 to the interaxal distance between the electrodes 9.

Device check. An experimental verification of the principal possibility of flaring of lead-containing briquettes with a moisture content of 4-6% was carried out on an experimental model of a melting (flare) section.

Pb concentrate of scrap scrap, pressed in the form of briquettes (diameter about 35 mm), containing on average%: lead - 65-70; moisture - up to 4-6.

As a result of melting, the following intermediates were obtained,%:

liquid metal fraction 35-45; solid dry fragments 35-45  "Volatile" the rest (including dust - 8-10).

As a result of the tests, it was established: 1. The flare section of the unit allows to process lead concentrate of high humidity (up to 4-6%) to obtain intermediates that are not fire and explosion hazardous for further loading and smelting in the electrothermal section. 2. There is a possibility of additional extraction of metal from the “volatile”, dust and gas components of the flare smelting as they pass through the gas transfer window into the electrothermal section and reduce the dust output.

Based on the positive results of the tests of the melting section and taking into account the authors' long experience with electrothermal and other furnace equipment (at the timber processing plant, now Ridder, Kazakhstan, etc.), a project for the reconstruction of the metallurgical production of TAZ OJSC is being implemented. The expected economic effect is more than 20 million rubles per year.

Claims (1)

A melting furnace for lead scrap of used automobile batteries, including a housing and a melting section located in it with a charge feed device and a burner, and an electrothermal section separated from the melting section by a partition not reaching the bottom, with electrodes, electrode holders, devices for the release of metal, slag and gas duct, characterized in that the lower edge of the partition is located above the level of the device for the release of slag, forming with the level of the melt gas transmission window of variable cross section, and oystvo tapping provided with a well connected with the overflow channel zone partitions, wherein the window section is selected in accordance with a predetermined ratio of furnace width to center distance between the electrodes, wherein the device is provided with charge feeding trough, superimposed on the stepped hearth inclined towards the septum.