Method for starting up a side-blown reduction furnace in a lead concentrate smelting process

Abstract

The present application relates to a kind of lead concentrate smelting process side-blown reduction furnace start-up method, belong to lead concentrate smelting technical field, the present application smelts lead concentrate with Isa furnace and side-blown reduction furnace combination, before starting up side-blown reduction furnace, from the raw material of lead concentrate added in Isa furnace start control, and the height control of lead bath before starting up, in the process of starting up, to the control of Isa furnace slagging slag type, the control of side-blown reduction furnace heat preservation fuel, the control of fuel etc. in the process of side-blown reduction furnace temperature rising, the starting-up time of side-blown reduction furnace is shortened from two days to 12 hours, greatly shorten the starting-up time;In addition, the present application's bath height control, in combination with Isa furnace slagging slag type control and heat preservation and temperature rising measure control, not only start up smoothly, and guarantee the integrity of copper water jacket.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of lead concentrate smelting, in particular to a method for starting up a side-blown reduction furnace in a lead concentrate smelting process. BACKGROUND

[0002] Lead matte is a copper, lead and iron sulfide produced in the lead ore smelting process or in the crude lead fire refining process. Its main components are FeS, Cu2S, PbS and ZnS. Lead matte contains not only copper and sulfur, but also a certain amount of valuable metals such as lead and zinc.

[0003] Lead concentrate smelting usually uses blast furnaces, oxygen bottom-blown furnaces, side-blown reduction furnaces and other smelting technologies. The use of Isa furnace combined with side-blown reduction furnace to smelt lead concentrate is a technology pioneered by our company. In this technology, lead, copper and zinc are first enriched and smelted in the Isa furnace. After lead enrichment, the lead-rich slag is discharged through the hot slag port into the side-blown reduction furnace. The side-blown reduction furnace uses natural gas and oxygen-enriched air as a heat source and adds granular coal and coke to control the reducing atmosphere in the furnace. After a certain operating period, high-temperature lead liquid and reduced lead slag are produced by reduction smelting. The produced lead liquid flows into the lead receiving pot through the siphon port of the reduction furnace from the chute.

[0004] The production of lead matte is inevitable during the smelting of copper-containing lead concentrate, especially during the long-term shutdown and heat preservation of the side-blown reduction furnace. As the temperature changes, a lead matte layer will form, dividing the side-blown reduction furnace into two parts. The upper layer of the lead matte layer is the reduction slag layer, and the lower layer is the lead liquid layer. Lead matte is a fusion body mainly composed of iron sulfide and lead sulfide. When the furnace is started up to resume production, the lead matte layer needs to be melted to restore normal operation of the side-blown reduction furnace. The lead matte layer has the characteristics of high melting point, high hardness and fast cooling, making it difficult to melt. The successful start-up of the side-blown reduction furnace mainly depends on the rapid melting of the lead matte layer, and the melting of the lead matte layer must be ensured while ensuring the height of the molten pool of the side-blown reduction furnace.

[0005] Currently, hot molten slag is repeatedly introduced and discharged into the side-blown reduction furnace to melt the lead matte layer using the heat of the hot molten slag. This method requires a large amount of hot molten slag, has a long start-up time, and produces a large amount of un-reduced molten slag during the start-up process. This part of un-reduced molten slag can only be stored and treated, causing environmental pressure and resource waste. In addition, the existing start-up method requires continuous discharge of molten slag to continuously utilize the heat of the discharged molten slag to melt the lead matte layer. In addition, due to the low temperature in the furnace hearth area, the siphon passage is easily burned through by the oxygen blowing pipe. This method mainly melts the lead matte layer through heat conduction and heat radiation of the hot molten slag. Each start-up time requires more than two days, and the success rate of start-up is only 48%. Not only does it consume a large amount of manpower and resources, but it also reduces the operation rate of the device, and once the equipment is damaged, the downtime is indefinitely extended, which has a great impact on the smelting of lead concentrate. SUMMARY

[0006] In order to overcome the problems in the background art, the present application provides a method for starting up a side-blown reduction furnace in a lead concentrate smelting process, which realizes a 100% success rate of starting up once by controlling the starting up process and the process indicators during the starting up process, and effectively avoids damage to the copper water jacket and the siphon passage during the starting up process, thereby ensuring the safety of the production device.

[0007] In order to achieve the above-mentioned purpose, the present application is realized by the following technical scheme:

[0008] The method for starting up a side-blown reduction furnace in a lead concentrate smelting process comprises the following steps:

[0009] (1) 24 hours before the planned shutdown of the side-blown reduction furnace, the copper content of the lead concentrate entering the Isa furnace is controlled to be less than 1wt%;

[0010] (2) after the last reduction of the side-blown reduction furnace is completed, the height of the lead bath of the side-blown reduction furnace is controlled to be 550mm-700mm, and the total bath height is controlled to be 1000mm-1200mm;

[0011] (3) the side-blown reduction furnace is kept warm for more than 12 hours, during which the compressed air supply of the side-blown reduction furnace is turned off, and 150Nm³ / h of natural gas and 300Nm³ / h of oxygen are introduced to keep the side-blown reduction furnace warm;

[0012] (4) the starting up time of the Isa furnace is determined, and the amount of material entering the Isa furnace is adjusted by the main control personnel of the Isa furnace to ensure that the amount of lead-rich slag discharged is 45-50t;

[0013] (5) 8-12 hours before starting up, the bath of the side-blown reduction furnace is warmed up, and natural gas and oxygen are introduced during the warming up process;

[0014] (6) the total bath height of the side-blown reduction furnace needs to be controlled to be 1800mm-2300mm when starting up, and the amount of material entering the Isa furnace is controlled to be 55-65t / t;

[0015] (7) 45-50t of lead-rich slag is discharged from the Isa furnace into the side-blown reduction furnace for temperature raising operation, the side-blown reduction furnace is warmed up, and granular coal is added during the warming up and melting process, the amount of granular coal added is 0.3-0.5 tons / time; the total bath height of the side-blown reduction furnace after the lead-rich slag is discharged needs to be controlled to be 1800mm-2300mm;

[0016] (8) while the lead ice-copper interlayer of the side-blown reduction furnace is warmed up and melted, the lead spout is heated to keep it in a high temperature state, so as to avoid the cold lead in the siphon passage from flowing out and blocking the lead spout; after warming up, the siphon is burned;

[0017] (9) When the siphon is boiled, the coal supply is adjusted in time according to the lead liquid flow of the lead tapping channel, and the reducing atmosphere of the side-blown reduction furnace is maintained, and the coal reduction is prohibited when there is no lead flow, and the reduction operation is carried out after the lead flow is normal.

[0018] Further, in step (4), the lead-rich slag produced by the Isa furnace has a slag type of SiO2 / Fe (mass ratio): 0.6-1.5, CaO / SiO2 (mass ratio): 0.3-0.65, and lead-rich slag Pb: 35%-45%.

[0019] Further, during the whole process of starting the furnace, the lead bath of the side-blown reduction furnace needs to be controlled below the height of the lance copper water jacket.

[0020] Further, after step (9), natural gas, oxygen, nitrogen and compressed air are started to be introduced, and the normal production of the side-blown reduction furnace is entered.

[0021] Further, the lead concentrate smelting adopts the combination of the Isa furnace and the side-blown reduction furnace, the lead concentrate is first smelted in the Isa furnace, and the obtained lead-rich slag enters the side-blown reduction furnace for lead recovery.

[0022] The beneficial effects of the present application are:

[0023] The present application fully utilizes the process characteristics of the combination of the Isa furnace and the side-blown reduction furnace for lead concentrate smelting, controls the raw materials of the lead concentrate added to the Isa furnace before starting the furnace of the side-blown reduction furnace, controls the height of the lead bath before starting the furnace and during the process of starting the furnace, controls the slag type of the Isa furnace, controls the fuel for temperature maintenance of the side-blown reduction furnace, and controls the fuel during the process of heating the side-blown reduction furnace, so that the starting time of the side-blown reduction furnace is shortened from two days to within 12 hours, and the starting time is greatly shortened.

[0024] The present application not only shortens the starting time of the side-blown reduction furnace, but also has a success rate of 100% for one-time starting of the side-blown reduction furnace, effectively solving the problem of difficult starting of the side-blown reduction furnace. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a structural schematic diagram of the side-blown reduction furnace used in the present application;

[0026] In the figure, 1 is lead-rich slag, 2 is copper matte interlayer, 3 is lead liquid, 4 is siphon, 5 is furnace brick, 6 is lance water jacket, 7 is lance, h1 is lead bath height, h2 is total bath height, and h3 is the height of the lance water jacket from the furnace bottom. DETAILED DESCRIPTION

[0027] In order to make the purposes, technical solutions and beneficial effects of the present application clearer, the technical solutions of the present application will be described in detail below. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0028] The method of the present application is suitable for smelting of lead concentrates in combination of an Isa furnace and a side-blown reduction furnace, and is proposed for the problem that the side-blown reduction furnace cannot be normally started up due to long-time shutdown and formation of a lead matte layer in the furnace.

[0029] The present application adopts the process of combination of an Isa furnace and a side-blown reduction furnace, the Isa furnace has strong adaptability to raw materials and can adapt to a wide range of indexes of lead concentrates, the side-blown reduction furnace has strong reduction capacity, the combination of the Isa furnace and the side-blown reduction furnace can fully exert the advantages of the two types of furnaces, and has the advantages of high capacity, low energy consumption and high metal recovery rate.

[0030] The starting-up method of the side-blown reduction furnace comprises the following steps:

[0031] (1) 24 hours before the planned shutdown of the side-blown reduction furnace, the copper content of the lead concentrate fed into the Isa furnace is controlled to be less than 1%, and by controlling the copper content of the lead concentrate, the thickness of the lead matte layer after the shutdown of the side-blown reduction furnace is reduced, and the difficulty of starting up is reduced; the high adaptability of the Isa furnace can adapt to the index adjustment of the lead concentrate.

[0032] (2) After the reduction of the last furnace of the side-blown reduction furnace is completed, the height of the lead bath is controlled to be 550mm-700mm to avoid high loss and damage to the copper water jacket of the lance; and the total bath height is controlled to be 1000mm-1200mm to avoid excessive bath height causing large vibration of the furnace body during the subsequent reduction process, and at the same time to ensure the safe bearing capacity of the hot slag package.

[0033] (3) The compressed air supply of the side-blown reduction furnace is turned off, and the side-blown reduction furnace is kept warm for more than 12 hours by using 150Nm³ / h of natural gas and 300Nm³ / h of oxygen; turning off the compressed air can avoid the generation of a large amount of flue gas and the loss of heat, which affects the bath temperature; and after the compressed air is turned off, more heat is generated by the natural gas.

[0034] (4) The starting-up time of the Isa furnace is determined, and the operation of the Isa furnace is controlled according to the bath height of the side-blown reduction furnace to ensure that the Isa furnace can discharge 45-50t of lead-rich slag.

[0035] (5) 8-12 hours before starting up, the bath of the side-blown reduction furnace is warmed up, and natural gas and oxygen are supplied during the warming-up process; in this step, only natural gas is used, and the calorific value of the natural gas is higher, which can improve the starting-up time of the side-blown reduction furnace.

[0036] (6) When starting up the side-blown reduction furnace, the total molten pool height should be controlled at 1800mm-2300mm, and the feed rate of the Isa furnace should be controlled at 55-65t / t; the lead-rich slag profile (in the following description, the material ratio of the slag profile is expressed as a mass ratio) is as follows: SiO2 / Fe: 0.6-1.5, CaO / SiO2: 0.3-0.65, and lead-rich slag Pb: 40%-45%. Through extensive experiments and demonstrations, the inventors have found that controlling the slag profile of the lead-rich slag has a significant impact on the success of furnace start-up and the start-up time. Moreover, the slag profile of the lead-rich slag also affects the reduction time of the side-blown reduction furnace and the reduction coal consumption.

[0037] (7) 45-50t of lead-rich slag is fed into the side-blown reduction furnace for heating. During the heating and melting process, granular coal is added at a rate of 0.3-0.5 tons per batch. The total molten pool height of the side-blown reduction furnace after the lead-rich slag is fed into the furnace must be controlled at 1800mm-2300mm. Granular coal is added intermittently to avoid reducing metallic lead in the slag and damaging the copper water jacket of the spray gun. The inventors have verified through extensive experiments that granular coal can only be added intermittently during the heating and melting process to ensure the atmosphere inside the side-blown reduction furnace and prevent lead from being reduced. Since the matte layer has not melted, the reduced lead liquid cannot settle to the lead liquid layer and concentrates above the matte layer. Once it comes into contact with the copper water jacket, it will corrode the copper water jacket and cause damage to the copper water jacket of the spray gun.

[0038] In addition, step (5) uses natural gas for heating, which not only has a higher calorific value, but also avoids the reduction of lead in this step. Furthermore, the inventors have demonstrated through experiments that if only natural gas is used for heating, the viscosity of the lead-rich slag on the lead matte layer will increase rapidly. Using granular coal for heating can prevent the viscosity of the lead-rich slag on the lead matte layer from increasing.

[0039] (8) While the side-blown reduction furnace heats up to melt the lead matte interlayer, it also heats the lead chute to keep it at a high temperature and prevent cold lead from flowing out of the siphon channel and clogging the lead chute; after heating up, the siphon burning operation is carried out.

[0040] (9) After the siphon is heated, adjust the coal feed rate according to the lead liquid flow rate of the lead chute (control the lead liquid to cover 1 / 2 of the height of the lead chute) to maintain the reducing atmosphere of the side-blown reduction furnace. Coal feeding for reduction is prohibited when there is no lead flow. Reduction operation is carried out after the lead flow rate is normal.

[0041] (10) After the lead flow rate is normal, start introducing natural gas, oxygen, nitrogen, and compressed air into the side-blown reduction furnace. The natural gas flow rate is 240-260 Nm³ / h, and the oxygen flow rate is 750 Nm³ / h. 3 / h, nitrogen 30-50Nm 3 / h, compressed air 200-250 Nm 3 / h, to restore normal production operation of the side-blown reduction furnace.

[0042] During the whole blowing process, the lead bath height of the side-blown reduction furnace needs to be controlled below the height of the copper water jacket of the lance.

[0043] In order to make the present application clearer, the following examples are used for detailed description. Example 1

[0044] A side-blown reduction furnace blowing method, comprising the following steps:

[0045] Preparation before parking:

[0046] (1) 24 hours before the planned parking of the side-blown reduction furnace, the copper content of the lead concentrate fed into the Isa furnace is controlled to be less than 1%.

[0047] Parking preparation:

[0048] (2) After the reduction of the last furnace of the side-blown reduction furnace is completed, the lead bath height is controlled to be 570 mm, and the total bath height is controlled to be 1200 mm.

[0049] (3) The compressed air supply of the side-blown reduction furnace is turned off, and the side-blown reduction furnace is kept warm for more than 12 hours by using 150 Nm³ / h of natural gas and 300 Nm³ / h of oxygen.

[0050] (4) The blowing time of the Isa furnace is determined, and the operation of the Isa furnace is controlled according to the bath height of the side-blown reduction furnace, so that the Isa furnace can discharge 45-50 t of lead-rich slag, the slag type of the lead-rich slag is SiO2 / Fe: 0.6, CaO / SiO2: 0.35, and the Pb content of the lead-rich slag is 40%.

[0051] Starting and warming up:

[0052] (5) 8 hours before the blowing, the bath of the side-blown reduction furnace is warmed up, and natural gas and oxygen are supplied during the warming up process.

[0053] (6) The total bath height of the side-blown reduction furnace needs to be controlled to be 1800-2300 mm when the side-blown reduction furnace is blown, and the feed amount of the Isa furnace is controlled to be 55-65 t / t.

[0054] (7) The Isa furnace discharges 45-50 t of lead-rich slag into the side-blown reduction furnace, and the total bath height of the side-blown reduction furnace after the lead-rich slag is discharged is 2000 mm; during the warming and melting process, granular coal is added, the amount of the granular coal is 0.35 tons per time, and the granular coal is added every 15-30 minutes.

[0055] (8) While the lead ice-copper interlayer of the side-blown reduction furnace is warmed and melted, the lead tank is heated to keep the lead tank in a high-temperature state, so as to avoid that the cold lead in the siphon flows out and blocks the lead tank; after warming up, the siphon is burned.

[0056] During the heating process, a carbon rod was inserted from the top of the furnace into the side-blown reduction furnace to detect the melting of the lead matte layer. The carbon rod detection showed that the melting time of the lead matte layer was 10.6 hours.

[0057] Restore the side-blown reduction furnace to normal operation:

[0058] (9) After the lead matte layer has been completely melted and the siphon channel has been opened (without low-temperature blockage) by using a carbon rod to detect it, adjust the coal feed rate (the coal feed rate affects the amount of lead reduced, that is, the amount of lead liquid discharged), control the lead liquid to cover 1 / 2 of the height of the lead chute, maintain the reducing atmosphere of the side-blown reduction furnace, and prohibit coal feeding for reduction when there is no continuous lead flow to prevent unmelted lead matte from entering the siphon with the lead liquid. If the lead flow is not continuous, the siphon will be blocked. After the lead flow is normal, the reduction operation will be carried out.

[0059] (10) After the lead flow rate is normal, start introducing natural gas, oxygen, nitrogen, and compressed air into the side-blown reduction furnace. The natural gas flow rate is 240-260 Nm³ / h, and the oxygen flow rate is 750 Nm³ / h. 3 / h, nitrogen 30-50Nm 3 / h, compressed air 200-250 Nm 3 / h, to restore normal production operation of the side-blown reduction furnace. Example 2

[0060] A method for starting up a side-blown reduction furnace includes the following steps:

[0061] Preparations before parking:

[0062] (1) 26 hours before the planned shutdown of the side-blown reduction furnace, control the copper content of the lead concentrate fed into the Isa furnace to be less than 1%.

[0063] Parking preparation:

[0064] (2) After the last reduction in the side-blown reduction furnace is completed, the height of the lead molten pool is controlled at 680 mm and the total height of the molten pool is controlled at 1000 mm.

[0065] (3) Turn off the compressed air supply to the side-blown reduction furnace, keep the side-blown reduction furnace warm for more than 12 hours, and keep the side-blown reduction furnace warm with 150 Nm³ / h of natural gas and 300 Nm³ / h of oxygen.

[0066] (4) Determine the start-up time of the Isa furnace and control the operation of the Isa furnace according to the height of the side-blown reduction furnace molten pool to ensure that the Isa furnace can release 45-50t of lead-rich slag. The lead-rich slag type is SiO2 / Fe: 1.4, CaO / SiO2: 0.60, and lead-rich slag Pb: 44%.

[0067] Warming up the car:

[0068] (5) Before starting the furnace, heat the side-blown reduction furnace molten pool 8 hours in advance, and introduce natural gas and oxygen during the heating process.

[0069] (6) When the side-blown reduction furnace is started, the total height of the molten pool should be controlled at 1800mm-2300mm, and the feed rate of the Isa furnace should be controlled at 55-65t / t.

[0070] (7) 45-50t of lead-rich slag is fed into the side-blown reduction furnace. After the lead-rich slag is fed into the side-blown reduction furnace, the total molten pool height of the side-blown reduction furnace is 2000mm. During the heating and melting process, granular coal is added at a rate of 0.5 tons / time, and granular coal is added every 15-30 minutes.

[0071] (8) While the side-blown reduction furnace heats up to melt the lead matte interlayer, it also heats the lead chute to keep it at a high temperature and prevent cold lead from flowing out of the siphon channel and clogging the lead chute; after heating up, the siphon burning operation is carried out.

[0072] During the heating process, a carbon rod was inserted from the top of the furnace into the side-blown reduction furnace to detect the melting of the lead matte layer. The carbon rod detection showed that the melting time of the lead matte layer was 10.2 hours.

[0073] Restore the side-blown reduction furnace to normal operation:

[0074] (9) After the lead matte layer has been completely melted and the siphon channel has been opened (without blockage) by using a carbon rod, adjust the coal feed rate to control the lead liquid to cover 1 / 2 of the height of the lead chute, maintain the reduction atmosphere of the side-blown reduction furnace, prohibit coal feeding for reduction when there is no lead flow, and carry out reduction operation after the lead flow is normal.

[0075] (10) After the lead flow rate is normal, start introducing natural gas, oxygen, nitrogen, and compressed air into the side-blown reduction furnace. The natural gas flow rate is 240-260 Nm³ / h, and the oxygen flow rate is 750 Nm³ / h. 3 / h, nitrogen 30-50Nm 3 / h, compressed air 200-250 Nm 3 / h, to restore normal production operation of the side-blown reduction furnace.

[0076] Comparative Example 1: Adding granular coal during step (5) of the heating process.

[0077] A method for starting up a side-blown reduction furnace includes the following steps:

[0078] Preparations before parking:

[0079] (1) 26 hours before the planned shutdown of the side-blown reduction furnace, control the copper content of the lead concentrate fed into the Isa furnace to be less than 1%.

[0080] Parking preparation:

[0081] (2) After the last reduction of the side-blown reduction furnace, the height of the lead bath is controlled at 680 mm, and the total bath height is controlled at 1000 mm.

[0082] (3) The compressed air supply of the side-blown reduction furnace is turned off, and the side-blown reduction furnace is kept warm for more than 12 hours. The side-blown reduction furnace is kept warm by using 150 Nm3 / h of natural gas and 300 Nm3 / h of oxygen.

[0083] (4) The start-up time of the Isa furnace is determined, and the operation of the Isa furnace is controlled according to the bath height of the side-blown reduction furnace to ensure that the Isa furnace can discharge 45-50 t of lead-rich slag. The slag type of the lead-rich slag is SiO2 / Fe: 1.4, CaO / SiO2: 0.60, and the Pb content of the lead-rich slag is 44%.

[0084] Start-up and temperature rise:

[0085] (5) Before starting up, the bath of the side-blown reduction furnace is warmed up 8 hours in advance. During the warming-up process, natural gas and oxygen are introduced through the lance, and granular coal is added from the cold material port of the side-blown furnace.

[0086] (6) The total bath height of the side-blown reduction furnace during start-up needs to be controlled at 1800-2300 mm, and the feed quantity of the Isa furnace is controlled at 55-65 t / t.

[0087] (7) The Isa furnace discharges 45-50 t of lead-rich slag into the side-blown reduction furnace, and the total bath height of the side-blown reduction furnace after the lead-rich slag is discharged into the side-blown reduction furnace is 2000 mm. Granular coal is added during the warming and melting process, and the amount of granular coal added is 0.5 tons per time, with an interval of 15-30 minutes. Due to the addition of granular coal in step (5), part of the lead has been reduced during the warming of the side-blown reduction furnace. If granular coal is continuously added in this step, the reduced lead cannot be discharged due to the non-melting of the lead matte layer, which causes corrosion of the copper water jacket. If the amount of granular coal is reduced, the warming rate will be greatly reduced, and increasing the amount of natural gas for warming will cause the viscosity of the lead-rich slag on the lead matte layer to increase dramatically, not only reducing the heat transfer effect, but also prolonging the reduction time of the material in the side-blown reduction furnace by 5-12% after start-up, and reducing the lead yield after reduction by 1.2-1.5%. This has a great impact on the smooth start of the side-blown reduction furnace.

[0088] (8) While the lead matte layer is being warmed and melted in the side-blown reduction furnace, the lead spout is also heated to maintain a high temperature state to prevent the cold lead in the siphon from flowing out and blocking the lead spout. After warming, the siphon is burned.

[0089] During the warming process, a carbon rod is inserted into the side-blown reduction furnace from the top of the furnace, and the melting of the lead matte layer is detected by the carbon rod. According to the carbon rod detection, the melting time of the lead matte layer is 16.5 hours.

[0090] Comparative Example 2, step (7) uses natural gas

[0091] A side-blown reduction furnace starting method, comprising the following steps:

[0092] Preparation before parking:

[0093] (1) 26 hours before the planned shutdown of the side-blown reduction furnace, the copper content of the lead concentrate fed into the Isa furnace is controlled to be less than 1%.

[0094] Parking preparation:

[0095] (2) After the last reduction of the side-blown reduction furnace, the height of the lead bath is controlled to be 680 mm, and the total bath height is controlled to be 1000 mm.

[0096] (3) The compressed air supply of the side-blown reduction furnace is turned off, and the side-blown reduction furnace is kept warm for more than 12 hours, and the side-blown reduction furnace is kept warm by 150 Nm³ / h of natural gas and 300 Nm³ / h of oxygen.

[0097] (4) Determine the starting time of the Isa furnace, control the operation of the Isa furnace according to the bath height of the side-blown reduction furnace, and ensure that the Isa furnace can discharge 45-50t of lead-rich slag, the slag type of the lead-rich slag is SiO2 / Fe: 1.4, CaO / SiO2: 0.60, and the Pb content of the lead-rich slag is 44%.

[0098] Starting and warming up:

[0099] (5) 8 hours before starting, the bath of the side-blown reduction furnace is warmed up, and natural gas and oxygen are introduced during the warming up process.

[0100] (6) The total bath height of the side-blown reduction furnace needs to be controlled at 1800mm-2300mm when starting, and the feed amount of the Isa furnace is controlled at 55-65t / t.

[0101] (7) The Isa furnace discharges 45-50t of lead-rich slag into the side-blown reduction furnace, and the total bath height of the side-blown reduction furnace after the lead-rich slag is discharged is 2000mm; natural gas is used to warm up and melt the lead matte layer.

[0102] (8) While warming up and melting the lead matte layer of the side-blown reduction furnace, the lead tank is heated to keep it in a high-temperature state to avoid the blockage of the lead tank caused by the flow of cold lead in the siphon; after warming up, the siphon is burned.

[0103] During the warming up process, a carbon rod is inserted into the side-blown reduction furnace from the top of the furnace, and the melting condition of the lead matte layer is detected by the carbon rod. According to the detection by the carbon rod, the melting time of the lead matte layer is 18.3 hours. The use of natural gas for warming up in step (7) will cause the material to be sticky and the heat transfer efficiency to be low, which will greatly affect the melting speed of the lead matte and the normal reduction of the side-blown reduction furnace after the lead matte is melted.

[0104] Resuming normal operation of the side-blown reduction furnace:

[0105] (9) After the carbon rod detects that the lead matte layer has completely melted and the siphon channel has been burned open (without low-temperature blockage), adjust the coal supply amount, control the lead liquid to cover 1 / 2 height of the lead tank, maintain the reducing atmosphere of the side-blown reduction furnace, prohibit coal reduction when there is no lead flow, and perform reduction operation after the lead flow is normal.

[0106] (10) After the lead flow is normal, start to pass natural gas, oxygen, nitrogen and compressed air into the side-blown reduction furnace, the natural gas is 240-260 Nm 3 / h, the oxygen is 750 Nm 3 / h, the nitrogen is 30-50 Nm 3 / h, and the compressed air is 200-250 Nm 3 / h, to resume normal production operation of the side-blown reduction furnace.

[0107] Note: In the case of no special description, the percentage content represented by "%" in the present application is mass percentage content.

[0108] Finally, it should be pointed out that the above preferred embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present application.

Claims

1. A method for starting up a side-blown reduction furnace in a lead concentrate smelting process, characterized by The method comprises the following steps: (1) 24 hours before the side-blown reduction furnace is planned to be stopped, the copper content of the lead concentrate entering the Isa furnace is controlled to be less than 1wt%; (2) after the last reduction of the side-blown reduction furnace is completed, the height of the lead bath is controlled to be 550mm-700mm, and the total bath height is controlled to be 1000mm-1200mm; (3) the side-blown reduction furnace is kept for more than 12 hours, during which the compressed air supply of the side-blown reduction furnace is turned off, and 150Nm³ / h of natural gas and 300Nm³ / h of oxygen are supplied to keep the side-blown reduction furnace; (4) the time of starting the Isa furnace is determined, the entering amount of the material is adjusted by the main control personnel of the Isa furnace according to the bath height of the side-blown reduction furnace, so that the 45-50t of lead-rich slag can be discharged; (5) 8-12 hours before the furnace is started, the bath of the side-blown reduction furnace is heated, and natural gas and oxygen are supplied during the heating process; (6) when the side-blown reduction furnace is started, the total bath height is controlled to be 1800mm-2300mm, and the feeding amount of the Isa furnace is controlled to be 55-65t / h; (7) the 45-50t of lead-rich slag is discharged from the Isa furnace into the side-blown reduction furnace to heat the side-blown reduction furnace, and 0.3-0.5 tons of granular coal is added during the heating and melting process; the total bath height of the side-blown reduction furnace after the lead-rich slag is discharged is controlled to be 1800mm-2300mm; (8) while the lead-rich slag layer of the side-blown reduction furnace is heated and melted, the lead channel is heated to keep the lead channel in a high-temperature state, so that the cold lead in the siphon is prevented from flowing out and blocking the lead channel; after heating, the siphon is burned; (9) after the siphon is burned, the coal feeding amount is adjusted according to the lead flow of the lead channel to maintain the reduction atmosphere of the side-blown reduction furnace; no coal is fed for reduction when there is no lead flow, and the reduction is performed after the lead flow is normal.

2. The method according to claim 1, wherein the method is characterized by: In step (4), the lead-rich slag discharged from the Isa furnace has a mass ratio of SiO2 to Fe of 0.6-1.5 and a mass ratio of CaO to SiO2 of 0.3-0.65, and the Pb content is 35%-45%.

3. The method of starting up a side-blown reduction furnace in a lead concentrate smelting process according to claim 1, characterized in that, During the whole starting process, the lead bath of the side-blown reduction furnace is controlled to be below the copper water jacket height of the lance.

4. The method of starting up a side-blown reduction furnace for smelting of lead concentrates according to claim 1, characterized in that, After step (9), natural gas, oxygen, nitrogen and compressed air are supplied to the side-blown reduction furnace for normal production.

5. The method according to any one of claims 1 to 4, wherein the method is characterized by, The lead concentrate is smelted by using the combination of the Isa furnace and the side-blown reduction furnace, the lead concentrate is first smelted in the Isa furnace, and the lead-rich slag obtained is discharged into the side-blown reduction furnace for lead recovery.

Images