Oxygen blowing and coal injection regenerated lead smelting furnace and oxygen blowing and coal injection method

Abstract

An oxygen-blowing and coal-spraying regenerated lead smelting furnace and an oxygen-blowing and coal-spraying method belong to the technical field of non-ferrous metal smelting. The discharge port at the bottom of the coal-spraying tank is connected to the coal-spraying machine; the inlet end of the coal-spraying machine is connected to the gas outlet port of the gas storage tank, the outlet end of the coal-spraying machine is connected to the coal powder inlet of the coal-spraying oxygen gun through the coal-spraying pipe, and the coal-spraying oxygen gun is inserted into the smelting furnace body; the gas outlet port of the gas storage tank is connected to the coal-spraying tank, and the gas inlet port of the gas storage tank is connected to the air compressor through the gas storage pressurizing valve; the upper cap of the coal-spraying tank is also connected to a coal-filling valve, a pressure gauge and an air inlet valve, and the upper inlet end of the coal-filling valve is connected to a coal hopper; the oxygen station is connected to the oxygen inlet of the coal-spraying oxygen gun; the gas outlet port of the gas storage tank is connected to the compressed air inlet of the coal-spraying oxygen gun. Advantages: simple structure, low manufacturing cost; more complete combustion, improved smelting efficiency; coal powder penetrates into the molten liquid slag, accelerates the decomposition of lead sulfate, greatly reduces the consumption of iron filings or iron ore, and reduces the slag production.

Description

Technical Field

[0001] The invention belongs to the technical field of nonferrous metal smelting, and in particular relates to an oxygen blowing and coal injection secondary lead smelting furnace and an oxygen blowing and coal injection method. Background Art

[0002] During metal smelting, coal powder needs to be added to the smelting furnace body. The role of coal powder in the smelting furnace body is to provide the heat required for the smelting process, and also to serve as a reducing agent for reducing metals. There are various ways to add coal and coal injection devices, which can basically meet production needs. Conventional coal injection devices are mainly composed of raw coal storage and transportation, coal powder preparation, coal powder transportation, coal powder injection, dry gas preparation and gas supply power system. The equipment is complex, occupies a large area, has a large investment, and has high operating costs. Improper operation often causes tank explosions, which harms the equipment and even endangers people's lives. A large amount of coal powder will be blown into the air, which not only pollutes the air, but also causes a lot of waste. At the same time, the structural design of the existing coal injection device has certain defects. The coal powder cannot be directly sprayed into the high-temperature molten liquid for deep reduction, causing the combustion conditions of the coal powder in the furnace to deteriorate and the combustion rate to decrease.

[0003] With the continuous development of my country's automobile industry and electric vehicle industry, the amount of waste lead-acid batteries produced each year is as high as 6 million tons, and waste lead-acid batteries have become a huge recyclable resource. The proportion of recycled lead production in developed countries such as Europe, the United States, and Japan accounts for more than 90% of the total lead production, while my country's recycled lead production accounts for only about 40%. Therefore, the development of the recycled lead industry is the only way for my country to develop a circular economy and build a conservation-oriented society. In recent years, my country's recycled lead industry has made significant progress. In response to the problems of low recovery rate, backward equipment, high cost, and difficulty in treating low-concentration SO2 in the smelting of lead mud from domestic waste lead-acid batteries, some domestic scientific research institutions and enterprises have studied some new smelting processes. The wet process includes pre-desulfurization-electrolytic deposition process and solid-phase electrolytic reduction lead process, and the pyrometallurgical process includes pre-desulfurization-low-temperature reduction smelting process. However, the cost of wet desulfurization is high, and the by-products sodium sulfate or ammonium sulfate are poor in market, so they are less used. Summary of the invention

[0004] The purpose of the present invention is to provide an oxygen blowing and coal injection secondary lead smelting furnace and an oxygen blowing and coal injection method to solve the problems in the prior art of insufficient combustion of coal powder and inability to directly spray coal powder into the molten liquid, resulting in low smelting efficiency.

[0005] The object of the present invention is achieved in this way: the present invention comprises an oxygen blowing and coal injection secondary lead smelting furnace and an oxygen blowing and coal injection method based on the oxygen blowing and coal injection secondary lead smelting furnace.

[0006] The oxygen-blowing and coal-injection secondary lead smelting furnace includes: a coal-injection tank, a pressure gauge, a coal-adding valve, a coal hopper, a safety valve, an air intake valve, an air intake flow meter, an air intake pressure regulating valve, an air jet pressure regulating valve, an air jet flow meter, an air storage pressurizing valve, an air compressor, an air storage tank, a coal-injection machine, a coal-injection pipe, a coal-injection oxygen gun, an oxygen station, an oxygen pressure regulating valve, an oxygen flow meter, a compressed air pressure regulating valve, a compressed air flow meter and a smelting furnace body;

[0007] The discharge port at the bottom of the coal injection tank 1 is connected to the feed port of the coal injection machine; the inlet end of the coal injection machine is connected to the gas outlet port of the gas storage tank through a jet flowmeter and a jet pressure regulating valve connected in sequence, the outlet end of the coal injection machine is connected to one end of the coal injection pipe, the other end of the coal injection pipe is connected to the pulverized coal inlet of the coal injection oxygen gun, and the gun barrel of the coal injection oxygen gun is inserted into the smelting furnace body; the gas outlet port of the gas storage tank is also connected to the coal injection tank through an air inlet pressure regulating valve, an air inlet flowmeter and an air inlet valve, and the air inlet port of the gas storage tank is connected to the air compressor through an air storage pressurizing valve; a coal filling valve, a pressure gauge and an air inlet valve are also connected to the upper cap of the coal injection tank, and a coal hopper is connected to the upper inlet end of the coal filling valve; the oxygen station is connected to the oxygen inlet of the coal injection oxygen gun through a pipeline and an oxygen pressure regulating valve and an oxygen flowmeter connected in series; the gas outlet port of the gas storage tank is also connected to the compressed air inlet of the coal injection oxygen gun through a pipeline and a compressed air pressure regulating valve and a compressed air flowmeter connected in series.

[0008] The coal injection machine comprises: a coal injection motor, a reducer, a coupling, a feed port, a machine base and a coal mixer; the coal mixer is installed on the machine base, and a feed port is provided at the upper end of the coal mixer; a reducer is provided at one end of the coal mixer, and an input shaft of the reducer is connected to an output shaft of the coal injection motor, and the output shaft of the reducer is connected to a rotor shaft of the coal mixer through a coupling; an air inlet and a coal injection outlet are respectively connected to both ends of the lower side of the coal mixer body.

[0009] The coal mixer comprises: a machine body, a sealing ring, a bearing, an air inlet, a coal injection outlet, a rotor shaft, a rotor and fins; the two ends of the rotor are connected to the two ends of the machine body through bearings, and a sealing ring is connected to the rotor shaft inside the bearing; a rotor cavity matching the rotor is provided in the middle position of the machine body, and the rotor is located in the rotor cavity; a coal inlet corresponding to the coal inlet valve is provided on the upper side wall of the machine body, and the coal inlet is communicated with the rotor cavity; the air inlet and the coal injection outlet at the two ends of the lower side of the machine body are communicated with the rotor cavity and are located on the same axis.

[0010] The rotor comprises: a coal injection channel, a rotor shaft, fins and a rotor body; the rotor body is cylindrical, and the rotor shaft is connected to both ends of the rotor body, and the rotor shaft and the cylinder of the rotor body are on the same axis; a plurality of fins are evenly distributed on the outer wall of the rotor body, and the fins are axially arranged on the rotor body to form a groove between two fins, and the groove between the two fins and the air inlet and the coal injection outlet constitute the coal injection channel.

[0011] The coal-injected oxygen lance comprises: a gas collecting cylinder, an oxygen inlet, an oxygen chamber, a pulverized coal inlet, a pulverized coal pipe, an oxygen pipe, a compressed air inlet, a compressed air chamber and a compressed air pipe; a partition is welded inside the gas collecting cylinder, the partition divides the gas collecting cylinder into two independently sealed oxygen chambers and compressed air chambers, the wall panels and partitions at both ends of the oxygen chamber and the compressed air chamber are provided with holes, and the three holes are on the same axis; the pulverized coal pipe, the oxygen pipe and the compressed air pipe are sleeved together in sequence and connected to the three holes respectively, and there are gaps between the pulverized coal pipe, the oxygen pipe and the compressed air pipe;

[0012] The pulverized coal pipe is sealed and welded to the inner side of the hole of the end wall plate of the oxygen chamber, and a pulverized coal inlet is connected to the outer side of the hole, the pulverized coal pipe is communicated with the pulverized coal inlet, and an oxygen inlet is connected to the side wall plate of the oxygen chamber, and the oxygen inlet is communicated with the oxygen chamber;

[0013] The oxygen pipe is connected to the partition, the oxygen pipe is welded and sealed on the partition on one side of the compressed air chamber, there is a gap between the oxygen pipe and the partition on one side of the oxygen chamber, and the oxygen pipe is communicated with the oxygen chamber;

[0014] The compressed air pipe is seal-welded on the outer side of the end wall plate of the compressed air chamber. There is a gap between the compressed air pipe and one side wall plate of the compressed air chamber, and the compressed air pipe is communicated with the compressed air chamber. A compressed air inlet is connected to the side wall plate of the compressed air chamber, and the compressed air inlet is communicated with the compressed air chamber.

[0015] The bottom of the coal injection tank is provided with at least one discharge port, the discharge port is connected with a coal discharge valve; the outlet end of the coal discharge valve is connected with a coal injection machine.

[0016] The bottom of the coal injection tank is provided with a plurality of discharge ports, and each discharge port is connected with a coal injection machine.

[0017] Multiple discharge ports at the bottom of the coal injection tank are all connected with coal discharge valves; and the outlet end of each coal discharge valve is connected with a coal injection machine.

[0018] The steps of oxygen blowing and coal injection are as follows:

[0019] Step 1: Turn on the air compressor to deliver compressed air to the air storage tank, and provide compressed air with a flow rate of 100-200m³ / h and a pressure of 0.2-0.5Mpa to the coal injection tank through the air inlet valve; provide compressed air with a flow rate of 200-400m³ / h and a pressure of 0.4-1.0Mpa to the coal injection machine through the jet pressure regulating valve;

[0020] Step 2, conveying coal powder to the coal mixer through the coal injection tank and the coal adding valve 3;

[0021] Step 3, start the coal injection motor, the rotor shaft drives the rotor to rotate at high speed, the coal injection machine starts to work, the coal powder from the coal injection tank enters the axially distributed grooves on the rotor, and the air inlet and coal injection outlet form a coal injection channel, the coal powder particles are fully mixed with the compressed air and transported to the coal injection pipe through the coal injection outlet;

[0022] Step 4: Use the coal-injection oxygen gun connected to the coal-injection pipe to directly spray the coal powder particles into the molten liquid slag 30-50cm below, implement strong blowing and spraying to fully diffuse the coal powder particles, thereby improving the distribution uniformity of the coal powder. At the same time, start the oxygen station to spray 100-600 m³ / h of oxygen or oxygen-enriched air with a pressure of 0.4-1.0Mpa into the molten liquid slag through the coal-injection oxygen gun.

[0023] The main components of waste lead-acid battery lead mud are lead sulfate, lead oxide and metallic lead, including 45-65% lead sulfate, 20-35% lead oxide and a small amount of metallic lead.

[0024] The purpose of adding coal powder is to supplement heat and reducer of lead mud, ensure the smooth chemical reaction in the furnace, and improve the fluidity of slag, which is conducive to the separation of slag and lead and the smooth release of slag. Coal powder has a strong ability to penetrate in slag, and it is easy to enter the lower part of the molten pool and react to produce a large number of bubbles. On the one hand, it is very beneficial to increase the temperature of the lower part of the molten pool, improve the quality of crude lead, and accelerate the stirring of the molten pool; on the other hand, the coal powder is stirred by the compressed air or oxygen or oxygen-enriched air blown into the coal-injected oxygen lance, diffuses into the high-temperature molten slag, is surrounded and burned, and the coal powder undergoes a series of chemical reactions with oxygen, lead sulfate, and lead oxide.

[0025] The combustion of pulverized coal provides heat energy and participates in the reduction reaction of metallic lead;

[0026] C+O2=CO2

[0027] 2C+O2=2CO

[0028] CO2+C=2CO

[0029] PbO+C=Pb+CO

[0030] PbO+CO=Pb+CO2

[0031] Lead sulfate in lead mud undergoes many reactions in an oxidation-reduction atmosphere, including thermal decomposition of lead sulfate, reduction of lead sulfate, and interactive reactions. The reactions of lead sulfate are as follows:

[0032] 2PbSO4=PbO·PbSO4+SO3

[0033] PbSO4=PbO+SO2+1 / 2O2

[0034] PbSO4+4CO=PbS+4CO2

[0035] PbSO4+4C=PbS+4CO

[0036] PbSO4+PbS=2Pb+2SO2

[0037] 2PbO+PbS=3Pb+SO2

[0038] PbS+Fe=Pb+FeS

[0039] By continuously injecting coal powder and compressed air or oxygen or oxygen-enriched air, the smelting reaction process is accelerated, the lead compounds in the slag are reduced to metallic lead, and the slag and lead are separated.

[0040] Compared with the prior art, the above technical solution has the following beneficial effects:

[0041] 1. The device has a simple structure, is easy to implement, has low manufacturing cost, and is friendly to the working environment.

[0042] 2. The pulverized coal is fully mixed with compressed air or oxygen or oxygen-enriched air, which makes the combustion more complete, increases the combustion rate and furnace temperature of the pulverized coal, and effectively improves the smelting efficiency.

[0043] 3. The complicated coal powder grinding process is eliminated, the coal powder particle size range is wide, and the requirement for coal powder moisture is not high.

[0044] 4. Reduce the melting temperature, save resources and reduce production costs.

[0045] 5. Emission reduction: the amount of flue gas, smoke dust, SO2 and Pb dust emissions are significantly reduced.

[0046] 6. Coal powder and air or oxygen or oxygen-enriched air penetrate into the molten liquid slag, accelerating the decomposition of lead sulfate. The decomposed lead oxide is reduced to metallic lead by coal powder or carbon monoxide, greatly reducing the consumption of iron filings or iron ore, thereby reducing the slag production. The slag production per ton of lead is less than 50% of the traditional one.

[0047] 7. The metal is fully reduced, the smelting time is shortened, and the fluidity of the slag is improved, which is conducive to the separation of slag and lead and the smooth discharge of slag. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic diagram of the structure of the present invention.

[0049] Figure 2 This is a schematic diagram of the structure of Example 2 of the present invention.

[0050] Figure 3 It is a structural schematic diagram of the coal injection machine of the present invention.

[0051] Figure 4 A schematic diagram of the rotor structure of the coal injection machine of the present invention.

[0052] Figure 5 for Figure 3 Schematic diagram of the side structure.

[0053] Figure 6 It is a schematic diagram of the structure of the coal injection oxygen lance of the present invention.

[0054] Figure 7 This is a structural diagram of the combined outlet end face of the pulverized coal pipe, oxygen pipe and compressed air pipe of the coal-injection oxygen gun.

[0055] Figure 8 It is a structural schematic diagram of a coal injection tank with multiple coal outlets of the present invention.

[0056] In the figure, 1. coal injection tank; 2. pressure gauge; 3. coal adding valve; 4. coal hopper; 5. safety valve; 6. air intake valve; 7. air intake flow meter; 8. air intake pressure regulating valve; 9. coal outlet valve; 10. jet pressure regulating valve; 11. jet flow meter; 12. gas storage pressurizing valve; 13. air compressor; 14. gas storage tank; 15. coal injection machine; 16. coal injection pipe; 17. coal injection oxygen gun; 18. oxygen station; 19. oxygen pressure regulating valve; 20. oxygen flow meter; 21. compressed air pressure regulating valve; 22. compressed air flow meter; 23. smelting furnace body.

[0057] 15-1, coal-injection motor; 15-2, reducer; 15-3, coupling; 15-4, machine body; 15-5, feed inlet; 15-6, sealing ring; 15-7, bearing; 15-8, air inlet; 15-9, coal-injection channel; 15-10, coal-injection outlet; 15-11, machine base; 15-12, shaft shaft; 15-13, rotor; 15-14, fin.

[0058] 17-1, gas cylinder; 17-2, oxygen inlet; 17-3, oxygen chamber; 17-4, coal powder inlet; 17-5, coal powder pipe; 17-6, oxygen pipe; 17-7, compressed air inlet; 17-8, compressed air chamber; 17-9, compressed air pipe. DETAILED DESCRIPTION

[0059] Embodiment 1: The oxygen-blowing and coal-injection secondary lead smelting furnace comprises: a coal-injection tank 1, a pressure gauge 2, a coal-adding valve 3, a coal hopper 4, a safety valve 5, an air intake valve 6, an air intake flowmeter 7, an air intake pressure regulating valve 8, an air jet pressure regulating valve 10, an air jet flowmeter 11, an air storage pressurizing valve 12, an air compressor 13, an air storage tank 14, a coal-injection machine 15, a coal-injection pipe 16, a coal-injection oxygen gun 17, an oxygen station 18, an oxygen pressure regulating valve 19, an oxygen flowmeter 20, a compressed air pressure regulating valve 21, a compressed air flowmeter 22 and a smelting furnace body 23;

[0060] The discharge port at the bottom of the coal injection tank 1 is connected to the feed port 15-5 of the coal injection machine 15; the inlet end of the coal injection machine 15 is connected to the gas outlet port of the gas storage tank 14 through the sequentially connected jet flowmeter 11 and the jet pressure regulating valve 10, the outlet end of the coal injection machine 15 is connected to one end of the coal injection pipe 16, the other end of the coal injection pipe 16 is connected to the coal powder inlet of the coal injection oxygen gun 17, and the gun barrel of the coal injection oxygen gun 17 is inserted into the smelting furnace body 23; the gas outlet port of the gas storage tank 14 is also connected to the coal injection tank through the air inlet pressure regulating valve 8, the air inlet flowmeter 7 and the air inlet valve 6 The air inlet port of the gas storage tank 14 is connected to the air compressor 13 through the gas storage pressure valve 12; the upper cap of the coal injection tank 1 is also connected to the coal filling valve 3, the pressure gauge 2 and the air inlet valve 6, and the upper inlet end of the coal filling valve 3 is connected to the coal hopper 4; the oxygen station 18 is connected to the oxygen inlet of the coal injection oxygen gun 17 through a pipeline and a series-connected oxygen pressure regulating valve 19 and an oxygen flow meter 20; the gas outlet port of the gas storage tank 14 is also connected to the compressed air inlet of the coal injection oxygen gun 17 through a pipeline and a series-connected compressed air pressure regulating valve 21 and a compressed air flow meter 22. The coal injection tank 1 has at least one discharge port at the bottom.

[0061] The coal injection machine comprises: a coal injection motor 15-1, a reducer 15-2, a coupling 15-3, a feed port 15-5, a machine base 15-11 and a coal mixer; the coal mixer is installed on the machine base 15-11, and a feed port 15-5 is provided at the upper end of the coal mixer; a reducer 15-2 is provided at one end of the coal mixer, and an input shaft of the reducer 15-2 is connected to an output shaft of the coal injection motor 15-1, and an output shaft of the reducer 15-2 is connected to a rotor shaft 15-12 of the coal mixer through a coupling 15-3; an air inlet and a coal injection outlet are connected to both ends of the lower side of the coal mixer body.

[0062] The coal mixer comprises: a machine body 15-4, a sealing ring 15-6, a bearing 15-7, an air inlet 15-8, a coal injection outlet 15-10, a rotor shaft 15-12, a rotor 15-13 and a fin 15-14; the two ends of the rotor 15-13 are connected to the two ends of the machine body 15-4 through bearings 15-7, and a sealing ring 15-6 is connected to the rotor shaft inside the bearing 15-7; a rotor cavity matching the rotor 15-13 is provided in the middle position of the machine body 15-4, and the rotor is located in the rotor cavity; a coal inlet corresponding to the coal inlet valve is provided on the upper side wall of the machine body 15-4, and the coal inlet is communicated with the rotor cavity; the air inlet 15-8 and the coal injection outlet 15-10 at the two ends of the lower side of the machine body 15-4 are communicated with the rotor cavity and are located on the same axis.

[0063] The rotor 15-13 comprises: a coal injection channel 15-9, a rotor shaft 15-12, fins 15-14 and a rotor body; the rotor body is cylindrical, and the rotor shaft 15-12 is connected to both ends of the rotor body, and the rotor shaft 15-12 and the cylinder of the rotor body are on the same axis; a plurality of fins 15-14 are evenly distributed on the outer wall of the rotor body, and the fins 15-14 are arranged axially on the rotor body to form a groove between two fins 15-14, and the groove between the two fins and the air inlet 15-8 and the coal injection outlet 15-10 form a coal injection channel 15-9.

[0064] The coal injection oxygen lance comprises: a gas collecting cylinder 17-1, an oxygen inlet 17-2, an oxygen chamber 17-3, a pulverized coal inlet 17-4, a pulverized coal pipe 17-5, an oxygen pipe 17-6, a compressed air inlet 17-7, a compressed air chamber 17-8 and a compressed air pipe 17-9;

[0065] A partition is welded inside the gas collecting cylinder 17-1, which divides the gas collecting cylinder 17-1 into two independently sealed oxygen chambers 17-3 and compressed air chambers 17-8. There are holes on the wall panels and partitions at both ends of the oxygen chamber 17-3 and the compressed air chamber 17-8, and the three holes are on the same axis; the pulverized coal pipe 17-5, the oxygen pipe 17-6 and the compressed air pipe 17-9 are sequentially sleeved together and connected to the three holes respectively, and there are gaps between the pulverized coal pipe 17-5, the oxygen pipe 17-6 and the compressed air pipe 17-9;

[0066] The pulverized coal pipe 17-5 is sealed and welded to the inner side of the hole of the end wall plate of the oxygen chamber 17-3, and the outer side of the hole is connected to the pulverized coal inlet 17-4, the pulverized coal pipe 17-5 is communicated with the pulverized coal inlet 17-4, and the side wall plate of the oxygen chamber 17-3 is connected to the oxygen inlet 17-2, and the oxygen inlet 17-2 is communicated with the oxygen chamber 17-3;

[0067] The oxygen pipe 17-6 is connected to the partition, and the oxygen pipe 17-6 is welded and sealed on the partition on one side of the compressed air chamber 17-8. There is a gap between the oxygen pipe 17-6 and the partition on one side of the oxygen chamber 17-3, and the oxygen pipe 17-6 is connected to the oxygen chamber 17-3;

[0068] The compressed air pipe 17-9 is sealed and welded to the outer side of the end wall panel of the compressed air chamber 17-8. There is a gap between the compressed air pipe 17-9 and the side wall panel of the compressed air chamber 17-8, and the compressed air pipe 17-9 is communicated with the compressed air chamber 17-8; a compressed air inlet 17-7 is connected to the side wall panel of the compressed air chamber 17-8, and the compressed air inlet 17-7 is communicated with the compressed air chamber 17-8.

[0069] The steps of oxygen blowing and coal injection are as follows:

[0070] Step 1: Turn on the air compressor to deliver compressed air to the air storage tank, and provide the coal injection tank with a flow rate of 100-200m³ / h and a pressure of 0.2-0.5Mpa of compressed air through the air inlet valve 6; provide the coal injection machine 15 with a flow rate of 200-400m³ / h and a pressure of 0.4-1.0Mpa of compressed air through the jet pressure regulating valve 10;

[0071] Step 2, conveying coal powder to the coal mixer through the coal injection tank and the coal adding valve 3;

[0072] Step 3, start the coal injection motor 15-1, the rotor shaft 15-12 drives the rotor 15-13 to rotate at high speed, the coal injection machine 15 starts to work, the coal powder from the coal injection tank enters the axially distributed grooves on the rotor 15-13 and forms a coal injection channel 15-9 with the air inlet 15-8 and the coal injection outlet 15-10, and the coal powder particles are fully mixed with the compressed air and transported to the coal injection pipe 16 through the coal injection outlet 15-10;

[0073] Step 4: Use the coal-injection oxygen gun connected to the coal-injection pipe to directly spray the coal powder particles into the molten liquid slag 30-50cm below, implement strong blowing and spraying to fully diffuse the coal powder particles, thereby improving the distribution uniformity of the coal powder. At the same time, start the oxygen station to spray 100-600 m³ / h of oxygen or oxygen-enriched air with a pressure of 0.4-1.0Mpa into the molten liquid slag through the coal-injection oxygen gun.

[0074] The main components of waste lead-acid battery lead mud are lead sulfate, lead oxide and metallic lead, including 45-65% lead sulfate, 20-35% lead oxide and a small amount of metallic lead.

[0075] The purpose of adding coal powder is to supplement heat and reducer of lead mud, ensure the smooth chemical reaction in the furnace, and improve the fluidity of slag, which is conducive to the separation of slag and lead and the smooth release of slag. Coal powder has a strong ability to penetrate in slag, and it is easy to enter the lower part of the molten pool and react to produce a large number of bubbles. On the one hand, it is very beneficial to increase the temperature of the lower part of the molten pool, improve the quality of crude lead, and accelerate the stirring of the molten pool; on the other hand, the coal powder is stirred by the compressed air or oxygen or oxygen-enriched air blown by the coal-injection oxygen lance, diffuses into the high-temperature molten slag, is surrounded and burned, and the coal powder undergoes a series of chemical reactions with oxygen, lead sulfate, and lead oxide.

[0076] The combustion of pulverized coal provides heat energy and participates in the reduction reaction of metallic lead;

[0077] C+O2=CO2

[0078] 2C+O2=2CO

[0079] CO2+C=2CO

[0080] PbO+C=Pb+CO

[0081] PbO+CO=Pb+CO2

[0082] Lead sulfate in lead mud undergoes many reactions in an oxidation-reduction atmosphere, including thermal decomposition of lead sulfate, reduction of lead sulfate, and interactive reactions. The reactions of lead sulfate are as follows:

[0083] 2PbSO4=PbO·PbSO4+SO3

[0084] PbSO4=PbO+SO2+1 / 2O2

[0085] PbSO4+4CO=PbS+4CO2

[0086] PbSO4+4C=PbS+4CO

[0087] PbSO4+PbS=2Pb+2SO2

[0088] 2PbO+PbS=3Pb+SO2

[0089] PbS+Fe=Pb+FeS

[0090] By continuously injecting coal powder and compressed air or oxygen-enriched air, the smelting reaction process is accelerated, the lead compounds in the slag are reduced to metallic lead, and the slag and lead are separated.

[0091] Example 2: Figure 2 In the embodiment, the oxygen blowing and coal injection secondary lead smelting furnace further comprises: a coal outlet valve 9; a coal outlet valve 9 connected to the discharge port at the bottom of the coal injection tank 1; and a coal injection machine 15 connected to the outlet end of the coal outlet valve 9. Others are the same as those in embodiment 1.

[0092] Example 3: Figure 8 In the embodiment, the bottom of the coal injection tank 1 has no less than two discharge ports, and each discharge port is connected with a coal injection machine 15.

[0093] Embodiment 4: The multiple discharge ports at the bottom of the coal injection tank 1 are connected to the coal injection machine 15 through the coal discharge valve 9. Others are the same as in Embodiment 1.

Claims

1. An oxygen blowing and coal injection secondary lead smelting furnace, characterized by: The oxygen-blowing and coal-injection secondary lead smelting furnace includes: a coal-injection tank, a pressure gauge, a coal-adding valve, a coal hopper, a safety valve, an air intake valve, an air intake flow meter, an air intake pressure regulating valve, an air jet pressure regulating valve, an air jet flow meter, an air storage pressurizing valve, an air compressor, an air storage tank, a coal-injection machine, a coal-injection pipe, a coal-injection oxygen gun, an oxygen station, an oxygen pressure regulating valve, an oxygen flow meter, a compressed air pressure regulating valve, a compressed air flow meter and a smelting furnace body; The discharge port at the bottom of the coal injection tank is connected to the feed port of the coal injection machine; the inlet end of the coal injection machine is connected to the gas outlet port of the gas storage tank through a jet flowmeter and a jet pressure regulating valve connected in sequence, the outlet end of the coal injection machine is connected to one end of the coal injection pipe, the other end of the coal injection pipe is connected to the pulverized coal inlet of the coal injection oxygen gun, and the gun barrel of the coal injection oxygen gun is inserted into the smelting furnace body; the gas outlet port of the gas storage tank is also connected to the coal injection tank through an air intake pressure regulating valve, an air intake flowmeter and an air intake valve, and the gas intake port of the gas storage tank is connected to the air compressor through an air storage pressurizing valve; a coal filling valve, a pressure gauge and an air intake valve are also connected to the upper cap of the coal injection tank, and a coal hopper is connected to the upper inlet end of the coal filling valve; the oxygen station is connected to the oxygen inlet of the coal injection oxygen gun through a pipeline and an oxygen pressure regulating valve and an oxygen flowmeter connected in series; the gas outlet port of the gas storage tank is also connected to the compressed air inlet of the coal injection oxygen gun through a pipeline and a compressed air pressure regulating valve and a compressed air flowmeter connected in series.

2. The oxygen-blowing and coal-injecting secondary lead smelting furnace according to claim 1, characterized in that: The coal injection machine comprises: a coal injection motor, a reducer, a coupling, a feed port, a machine base and a coal mixer; the coal mixer is installed on the machine base, and a feed port is provided at the upper end of the coal mixer; a reducer is provided at one end of the coal mixer, and an input shaft of the reducer is connected to an output shaft of the coal injection motor, and the output shaft of the reducer is connected to a rotor shaft of the coal mixer through a coupling; an air inlet and a coal injection outlet are respectively connected to both ends of the lower side of the coal mixer body.

3. The oxygen blowing and coal injection secondary lead smelting furnace according to claim 2, characterized in that: The coal mixer comprises: a machine body, a sealing ring, a bearing, an air inlet, a coal injection outlet, a rotor shaft, a rotor and fins; the two ends of the rotor are connected to the two ends of the machine body through bearings, and a sealing ring is connected to the rotor shaft inside the bearing; a rotor cavity matching the rotor is provided in the middle position of the machine body, and the rotor is located in the rotor cavity; a coal inlet corresponding to the coal inlet valve is provided on the upper side wall of the machine body, and the coal inlet is communicated with the rotor cavity; the air inlet and the coal injection outlet at the two ends of the lower side of the machine body are communicated with the rotor cavity and are located on the same axis.

4. The oxygen blowing and coal injection secondary lead smelting furnace according to claim 2, characterized in that: The rotor comprises: a coal injection channel, a rotor shaft, fins and a rotor body; the rotor body is cylindrical, and the rotor shaft is connected to both ends of the rotor body, and the rotor shaft and the cylinder of the rotor body are on the same axis; a plurality of fins are evenly distributed on the outer wall of the rotor body, and the fins are axially arranged on the rotor body to form a groove between two fins, and the groove between the two fins and the air inlet and the coal injection outlet constitute the coal injection channel.

5. The oxygen blowing and coal injection secondary lead smelting furnace according to claim 1 is characterized in that: The coal-injected oxygen lance comprises: a gas collecting cylinder, an oxygen inlet, an oxygen chamber, a pulverized coal inlet, a pulverized coal pipe, an oxygen pipe, a compressed air inlet, a compressed air chamber and a compressed air pipe; a partition is welded inside the gas collecting cylinder, the partition divides the gas collecting cylinder into two independently sealed oxygen chambers and compressed air chambers, the wall panels and partitions at both ends of the oxygen chamber and the compressed air chamber are provided with holes, and the three holes are on the same axis; the pulverized coal pipe, the oxygen pipe and the compressed air pipe are sleeved together in sequence and connected to the three holes respectively, and there are gaps between the pulverized coal pipe, the oxygen pipe and the compressed air pipe; The pulverized coal pipe is sealed and welded to the inner side of the hole of the end wall plate of the oxygen chamber, and a pulverized coal inlet is connected to the outer side of the hole, the pulverized coal pipe is communicated with the pulverized coal inlet, and an oxygen inlet is connected to the side wall plate of the oxygen chamber, and the oxygen inlet is communicated with the oxygen chamber; The oxygen pipe is connected to the partition, the oxygen pipe is welded and sealed on the partition on one side of the compressed air chamber, there is a gap between the oxygen pipe and the partition on one side of the oxygen chamber, and the oxygen pipe is communicated with the oxygen chamber; The compressed air pipe is seal-welded on the outer side of the end wall plate of the compressed air chamber. There is a gap between the compressed air pipe and one side wall plate of the compressed air chamber, and the compressed air pipe is communicated with the compressed air chamber. A compressed air inlet is connected to the side wall plate of the compressed air chamber, and the compressed air inlet is communicated with the compressed air chamber.

6. The oxygen blowing and coal injection secondary lead smelting furnace according to claim 1 is characterized in that: The bottom of the coal injection tank is provided with at least one discharge port, the discharge port is connected with a coal discharge valve; the outlet end of the coal discharge valve is connected with a coal injection machine.

7. The oxygen blowing and coal injection secondary lead smelting furnace according to claim 1 is characterized in that: The bottom of the coal injection tank is provided with a plurality of discharge ports, and each discharge port is connected with a coal injection machine.

8. The oxygen blowing and coal injection secondary lead smelting furnace according to claim 1 is characterized in that: Multiple discharge ports at the bottom of the coal injection tank are all connected with coal discharge valves; and the outlet end of each coal discharge valve is connected with a coal injection machine.

9. The oxygen blowing and coal injection method for the oxygen blowing and coal injection secondary lead smelting furnace according to claim 1, characterized in that: The steps of oxygen blowing and coal injection are as follows: Step 1: Turn on the air compressor to deliver compressed air to the air storage tank, and provide compressed air with a flow rate of 100-200m³ / h and a pressure of 0.2-0.5Mpa to the coal injection tank through the air inlet valve; provide compressed air with a flow rate of 200-400m³ / h and a pressure of 0.4-1.0Mpa to the coal injection machine through the jet pressure regulating valve; Step 2, conveying coal powder to the coal mixer through the coal injection tank and the coal adding valve; Step 3, start the coal injection motor, the rotor shaft drives the rotor to rotate at high speed, the coal injection machine starts to work, the coal powder from the coal injection tank enters the axially distributed grooves on the rotor, and the air inlet and coal injection outlet form a coal injection channel, the coal powder particles are fully mixed with the compressed air and transported to the coal injection pipe through the coal injection outlet; Step 4: Use the coal-injection oxygen gun connected to the coal-injection pipe to directly spray the coal powder particles into the molten liquid slag 30-50cm below, implement strong blowing and spraying to fully diffuse the coal powder particles, thereby improving the distribution uniformity of the coal powder. At the same time, start the oxygen station to spray 100-600 m³ / h of oxygen or oxygen-enriched air with a pressure of 0.4-1.0Mpa into the molten liquid slag through the coal-injection oxygen gun.

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