Method for prolonging operating furnace life of fluidized bed furnace

Abstract

The invention relates to the technical field of fluidized bed furnace operation, and discloses a method for prolonging the service life of a fluidized bed furnace during operation, which comprises the following steps: controlling the water content of a furnace charge to be 9-10%; the content of copper in the furnace charge is controlled to be 0.9% or below, and the content of lead in the furnace charge is controlled to be 4% or below or 6% or below; controlling the roasting temperature; the pressure in the furnace is controlled between 1.2 m and 1.4 m or between 1.3 m and 1.4 m; controlling the oxygen content in the furnace; the temperature in the furnace is adjusted through two groups of water jackets, the furnace is used for a 48m < 2 > fluidized bed furnace when the lead content is below 4%, and the furnace is used for a 16m < 2 > fluidized bed furnace when the lead content is below 6%. By accurately controlling the moisture and metal content of the charging material, the roasting temperature, the pressure in the furnace and the oxygen content and optimizing a water jacket system, scaling and corrosion in the furnace are reduced, the material reaction efficiency is improved, the equipment operation condition is stabilized, and the temperature in the furnace is uniformly distributed, so that the service life of the fluidized bed furnace is remarkably prolonged, the maintenance requirement is reduced, and the production cost is reduced. And the operation period and the stability of the whole equipment are improved.

Description

Technical Field

[0001] The invention relates to the technical field of fluidized bed furnace operation, in particular to a method for extending the operation life of a fluidized bed furnace. Background Art

[0002] Fluidized bed furnaces are widely used in the non-ferrous metal smelting industry, especially in the oxidation roasting process of metals such as zinc and lead. Fluidized bed furnaces have become the preferred equipment for many smelting companies due to their efficient heat transfer and good reaction effect. However, as the use time increases, the scaling and corrosion problems in the fluidized bed furnace gradually emerge, affecting the normal operation and service life of the equipment. This problem seriously restricts the stability and economic benefits of the smelting process.

[0003] In the prior art, water jackets are usually used to control the temperature in the furnace to avoid equipment damage caused by local overheating. However, the design of water jackets is complex and the maintenance cost is high. Too many water jackets may also cause uneven temperature distribution in the furnace, affecting the roasting effect. In addition, the problem of low temperature control may lead to incomplete material reaction. The residual sulfide in the furnace will not only increase the fouling, but also cause further corrosion damage to the equipment.

[0004] In addition, metal impurities in the materials entering the furnace, especially the content of copper, lead and intolerant sulfur, have an important impact on the reaction in the furnace. These impurities will intensify the chemical reaction in the furnace at high temperatures, leading to increased corrosion of the furnace wall, thereby shortening the operating life of the furnace. Moisture control is also critical. Excessive moisture will lead to reduced roasting efficiency and increased energy consumption and operating costs.

[0005] Therefore, the existing fluidized bed furnace technology still has a large room for improvement in terms of how to better control the roasting temperature, reduce the dependence on the water jacket, control the composition of the materials entering the furnace, etc. To this end, the present invention proposes a method for extending the service life of a fluidized bed furnace. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a method for extending the operating life of a fluidized bed furnace, which solves the problems of short equipment life and unstable operation caused by uneven temperature, improper control of metal impurities and excessive moisture during high-temperature oxidation roasting in the existing fluidized bed furnace.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: A method for extending the service life of a fluidized bed furnace comprises the following steps:

[0008] Control the moisture content of the charge to be between 9-10%;

[0009] Control the copper content in the charge to be below 0.9%, and the lead content to be below 4% or below 6%;

[0010] Control roasting temperature;

[0011] Control the pressure in the furnace between 1.2-1.4m or 1.3-1.4m;

[0012] Control the oxygen content in the furnace;

[0013] The temperature inside the furnace is regulated by two sets of water jackets.

[0014] Preferably, the lead content is below 4% for 48m 2 Fluidized bed furnaces, where the lead content is less than 6%, are used for 16m 2 Boiling furnace.

[0015] Preferably, the calcination temperature is controlled between 980-1050°C.

[0016] Preferably, the furnace pressure is between 1.2-1.4m for 48m 2 Fluidized bed furnace, the pressure in the furnace is between 1.3-1.4m for 16m 2 Boiling furnace.

[0017] Preferably, the oxygen content in the furnace is controlled between 6.7-7.8%.

[0018] Preferably, the charge is a mixture of multiple zinc concentrates or a single zinc concentrate.

[0019] Preferably, the two groups of water jackets are located in different areas of the furnace, respectively, for accurately controlling the temperatures of the different areas.

[0020] Preferably, the sulfur content in the charge is 16m 2 In the fluidized bed furnace, it is controlled below 5% to reduce scaling and corrosion in the furnace.

[0021] The present invention provides a method for extending the service life of a fluidized bed furnace. The method has the following beneficial effects:

[0022] 1. The present invention reduces scaling and slag accumulation in the furnace, reduces corrosion and wear of the furnace wall, and thus prolongs the service life of the furnace body by controlling the moisture and metal content of the charge, especially controlling the moisture content to between 9 and 10%, the copper content to below 0.9%, the lead content to below 4% or 6%, and the sulfur content to below 5%.

[0023] 2. The present invention controls the roasting temperature between 980-1050°C, thereby ensuring that the materials react fully at an appropriate temperature, avoiding damage to the furnace body caused by excessively high or low temperatures, further reducing maintenance requirements, and extending the operating cycle of the equipment.

[0024] 3. The present invention optimizes the reaction conditions in the furnace by controlling the pressure in the furnace to be between 1.2-1.4 meters of water column (applicable to a 48 square meter boiling furnace) or between 1.3-1.4 meters of water column (applicable to a 16 square meter boiling furnace), thereby preventing damage to the furnace wall caused by pressure fluctuations and ensuring stable operation of the equipment.

[0025] 4. The present invention ensures that the oxidation reaction in the roasting process is fully carried out by controlling the oxygen content in the furnace between 6.7% and 7.8%, reduces the dust accumulation and scaling caused by incomplete reaction, and reduces the impact of oxygen content fluctuations on the furnace body, thereby extending the life of the equipment.

[0026] 5. The present invention adjusts the temperature in the furnace by two sets of water jackets, thereby achieving uniform temperature distribution in different areas, reducing thermal stress concentration and local overheating problems, reducing thermal damage to the furnace body, and further extending the service life of the furnace body. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Please see attached Figure 1 The embodiment of the present invention provides a method for extending the service life of a fluidized bed furnace, comprising the following steps:

[0030] Control the moisture content of the charge to be between 9-10%;

[0031] Control the copper content in the charge to be below 0.9%, and the lead content to be below 4% or below 6%;

[0032] Control roasting temperature;

[0033] Control the pressure in the furnace between 1.2-1.4m or 1.3-1.4m;

[0034] Control the oxygen content in the furnace;

[0035] The temperature inside the furnace is regulated by two sets of water jackets.

[0036] When the lead content is less than 4%, it is used for 48m 2 Fluidized bed furnaces, for use with lead content below 6% for 16m 2 Boiling furnace.

[0037] The firing temperature is controlled between 980-1050℃.

[0038] When the pressure in the furnace is between 1.2-1.4m, it is used for 48m 2 Fluidized bed furnace, for 16m when the pressure inside the furnace is between 1.3-1.4m 2 Boiling furnace.

[0039] The oxygen content in the furnace is controlled between 6.7-7.8%.

[0040] The charge is a mixture of various zinc concentrates or a single zinc concentrate.

[0041] The two sets of water jackets are located in different areas of the furnace and are used to accurately control the temperature of different areas.

[0042] The sulfur content in the charge is 16m 2 In the fluidized bed furnace, it is controlled below 5% to reduce scaling and corrosion in the furnace.

[0043] Embodiment 1

[0044] step:

[0045] The moisture content of the charge is controlled at 9.5%.

[0046] Control the copper content in the charge to be 0.8% and the lead content to be 3.5% (applicable to 48m 2 boiling furnace).

[0047] The calcination temperature was controlled at 1000°C.

[0048] Control the pressure in the furnace to 1.3m water column (applicable to 48m 2 boiling furnace).

[0049] The oxygen content in the furnace was controlled to be 7.0%.

[0050] The temperature of different areas in the furnace is regulated by two sets of water jackets.

[0051] Summary: Example 1 is a basic implementation scheme of the present invention, which prolongs the service life of the furnace body by accurately controlling the moisture and metal content of the charge and optimizing the roasting conditions.

[0052] Embodiment 2

[0053] step:

[0054] The moisture content of the charge is controlled at 9.3%.

[0055] Control the copper content of the charge to 0.7% and the lead content to 3.8% (applicable to 48m 2 boiling furnace).

[0056] The calcination temperature was controlled at 995°C.

[0057] Control the pressure in the furnace to 1.32m water column (applicable to 48m 2 boiling furnace).

[0058] The oxygen content in the furnace was controlled to be 7.1%.

[0059] The temperature of different areas in the furnace is regulated by two sets of water jackets.

[0060] Summary: Compared with Example 1, Example 2 further optimizes the control of moisture and metal content, especially reduces the copper content and adjusts the roasting temperature, so that the operating life of the furnace body is further extended.

[0061] Embodiment 3

[0062] step:

[0063] The moisture content of the charge is controlled at 9.2%.

[0064] The copper content in the charge is controlled to be 0.65% and the lead content is 3.3% (applicable to 48m 2 boiling furnace).

[0065] The calcination temperature was controlled at 990°C.

[0066] Control the pressure in the furnace to 1.28m water column (applicable to 48m 2 boiling furnace).

[0067] The oxygen content in the furnace was controlled to be 7.2%.

[0068] The temperature of different areas in the furnace is regulated by two sets of water jackets.

[0069] Summary: Based on Example 2, Example 3 further optimizes the roasting temperature and pressure parameters, making the furnace environment more stable and effectively reducing the wear and corrosion of the furnace body.

[0070] Embodiment 4

[0071] step:

[0072] The moisture content of the charge is controlled at 9.1%.

[0073] Control the copper content in the charge to be 0.6% and the lead content to be 3.0% (applicable to 48m 2 boiling furnace).

[0074] The calcination temperature was controlled at 985°C.

[0075] Control the pressure in the furnace to 1.25m water column (applicable to 48m 2 boiling furnace).

[0076] The oxygen content in the furnace was controlled to be 7.3%.

[0077] The temperature of different areas in the furnace is regulated by two sets of water jackets.

[0078] Summary: Example 4 further improves the stability and operation efficiency of the boiling furnace by further reducing the moisture and metal content and more accurately controlling the roasting temperature and the pressure in the furnace.

[0079] Embodiment 5

[0080] step:

[0081] The moisture content of the charge is controlled at 9.0%.

[0082] The copper content in the charge is controlled to be 0.55% and the lead content is 2.8% (applicable to 48m 2 boiling furnace).

[0083] The calcination temperature was controlled at 980°C.

[0084] Control the furnace pressure to 1.22m water column (applicable to 48m 2 boiling furnace).

[0085] The oxygen content in the furnace was controlled to be 7.4%.

[0086] The temperature of different areas in the furnace is regulated by two sets of water jackets.

[0087] Summary: Based on the first four embodiments, Example 5 further optimizes all key parameters, especially through stricter control of moisture and metal content, as well as precise temperature and pressure management, to maximize the operating life of the boiling furnace.

[0088] Summary:

[0089] Through the gradual deepening of Example 1 to Example 5, the present invention shows how to extend the operating life of the fluidized bed furnace by optimizing the composition of the charge, the roasting temperature, the pressure in the furnace, the oxygen content and the water jacket temperature control. Each example is further optimized on the basis of the previous example, and ultimately the operating efficiency and life of the fluidized bed furnace are significantly improved.

[0090] Experimental design and validation:

[0091] Experimental background:

[0092] Fluidized bed furnaces are used for roasting and heating materials in the metallurgical process. However, different roasting processes are used in the prior art, and these processes show different limitations in terms of furnace fouling, corrosion, uneven temperature distribution, and other issues. Prior art technologies such as non-oxidative roasting, cyclone furnaces, and fluidized bed furnace technologies are used in different application scenarios, but there are still major technical deficiencies when dealing with efficient oxidative roasting, especially in terms of equipment life, maintenance costs, and temperature control. The present invention proposes a technical solution to extend the operating life of a fluidized bed furnace by optimizing the moisture content, metal content, roasting temperature, furnace pressure, oxygen content, and water jacket regulation of zinc concentrate. In order to verify the effectiveness of the technical solution of the present invention, a series of comparative experiments were designed to compare the performance of the present invention with the prior art in actual applications.

[0093] Purpose:

[0094] Verify whether the present invention can significantly extend the operating life of the boiling furnace.

[0095] The differences in the control of furnace fouling and corrosion are compared between the present invention and the prior art samples.

[0096] Verify whether the present invention can significantly improve the uniformity of temperature distribution in the furnace.

[0097] The differences in maintenance frequency and cost between the present invention and the prior art samples are compared.

[0098] Experimental materials and equipment:

[0099] Sample preparation: five samples of embodiments of the present invention, and three samples of the prior art (non-oxidation roasting technology, cyclone furnace technology, fluidized bed furnace technology).

[0100] Experimental equipment:

[0101] 48m 2 Fluidized bed furnace and 16m 2 Boiling furnace

[0102] Thermocouple thermometer (for temperature monitoring)

[0103] Pressure sensor (for pressure monitoring)

[0104] Oxygen content monitoring equipment

[0105] Surface Analyzers (measures fouling and corrosion)

[0106] Time recorder

[0107] Experiment 1: Comparative experiment on the operating life of boiling furnace

[0108] Purpose:

[0109] The effect of the present invention in extending the service life of a fluidized bed furnace and reducing fouling and corrosion is verified.

[0110] Experimental steps:

[0111] Five samples of the present invention (Examples 1 to 5) and three samples of the prior art (non-oxidation roasting technology, cyclone furnace technology, fluidized bed furnace technology) were selected and heated at 48 m 2 and 16m 2 Running in a boiling furnace.

[0112] Set the roasting conditions for each sample and record the fouling and corrosion conditions in the furnace.

[0113] Measure and record the furnace operating life (in hours).

[0114] Table 1:

[0115] Sample No. Running time (hours) Thickness of scale (mm) Corrosion area in furnace (%) Embodiment 1 6500 0.6 8％ Embodiment 2 6800 0.5 7％ Embodiment 3 7000 0.4 6％ Embodiment 4 7300 0.3 5％ Embodiment 5 7500 0.2 4％ Non-oxidation roasting technology 3500 1.5 20％ Cyclone furnace technology 4000 1.2 15％ Fluidized bed furnace technology 4500 1.0 12％

[0116] Experimental summary:

[0117] According to experimental data, the samples of the present invention are significantly better than the samples of the prior art in terms of operating life. Due to the lack of oxygen control, the non-oxidation roasting technology causes the scale thickness in the furnace to reach 1.5 mm, the corrosion area to reach 20%, and the operating time is only 3500 hours. Although the cyclone furnace technology and fluidized bed furnace technology have solved the problems of scaling and corrosion to a certain extent, the operating life is still significantly shorter than that of the embodiments of the present invention. In contrast, Example 5 of the present invention achieves the best performance, with good scaling and corrosion control, and the operating time extended to 7500 hours, which proves the superiority of the present invention in extending the life of the boiling furnace.

[0118] Experiment 2: Temperature distribution uniformity experiment

[0119] Purpose:

[0120] The effect of the present invention on improving the uniformity of temperature distribution in the furnace was verified.

[0121] Experimental steps:

[0122] The temperature was measured at different locations in the furnace using thermocouples.

[0123] The temperature distribution of the samples of the present invention and the samples of the prior art were monitored respectively, and the standard deviation of the temperature was calculated.

[0124] Table 2:

[0125]

[0126] Experimental summary:

[0127] According to experimental data, the temperature distribution uniformity of the prior art samples is poor, and the standard deviation of the non-oxidation roasting technology is as high as 20°C, indicating that the temperature fluctuation in the furnace is large and there is local overheating. The standard deviation of the cyclone furnace and fluidized bed furnace technology has improved, but it has not yet reached the ideal state. The samples of the present invention perform better in temperature control, especially Example 5, whose standard deviation is only 0.8°C, proving the significant improvement of the present invention in temperature distribution uniformity.

[0128] Experiment 3: Maintenance frequency and cost experiment

[0129] Purpose:

[0130] Verify the effectiveness of the present invention in reducing maintenance frequency and cost.

[0131] Experimental steps:

[0132] The number of maintenances during operation of the samples of the present invention and the samples of the prior art was recorded.

[0133] Calculate the time and cost of each maintenance.

[0134] Table 3:

[0135] Sample No. Maintenance times Maintenance time (hours) Maintenance cost (yuan) Embodiment 1 5 30 3000 Embodiment 2 4 24 2500 Embodiment 3 3 20 2000 Embodiment 4 2 15 1500 Embodiment 5 1 10 1000 Non-oxidation roasting technology 12 72 7200 Cyclone furnace technology 10 60 6000 Fluidized bed furnace technology 8 48 5000

[0136] Experimental summary:

[0137] According to experimental data, the prior art samples performed poorly in terms of maintenance frequency and cost. Due to serious fouling and corrosion problems, the non-oxidation roasting technology requires up to 12 maintenance times, with a maintenance cost of 7,200 yuan. The maintenance requirements of cyclone furnace technology and fluidized bed furnace technology have been reduced, but they still require more maintenance. The samples of the present invention performed well in terms of maintenance requirements. Example 5 only required 1 maintenance at a cost of 1,000 yuan, which proves the advantages of the present invention in reducing maintenance frequency and cost.

[0138] Summary:

[0139] Through the comparison of the data of the three experiments, the following conclusions can be drawn:

[0140] Extended operating life: The operating time of the samples of the present invention is significantly higher than that of the prior art samples, and fouling and corrosion phenomena are significantly reduced, especially in Example 5, whose operating life reaches 7500 hours, while the operating time of the sample of the non-oxidation roasting technology is only 3500 hours, showing a significant gap.

[0141] Improved uniformity of temperature distribution: The temperature distribution of the samples of the present invention is more uniform. The standard deviation of Example 5 is only 0.8°C, while the standard deviation of the samples of the non-oxidation roasting technology is as high as 20°C, showing the significant advantages of the present invention in temperature control.

[0142] Reduce maintenance frequency and cost: The maintenance frequency and cost of the samples of the present invention are significantly lower than those of the prior art samples. The maintenance frequency of Example 5 is only 1 time, and the maintenance cost is 1,000 yuan, while the maintenance frequency of the sample of the non-oxidation roasting technology is as high as 12 times, and the cost is 7,200 yuan, which reflects the significant effect of the present invention in reducing maintenance requirements and operating costs.

[0143] In summary, the present invention has significant advantages over the prior art in extending the service life of the boiling furnace, improving the uniformity of temperature distribution in the furnace, reducing the number of maintenance times and reducing costs.

[0144] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for extending the service life of a fluidized bed furnace, characterized in that: The following steps are involved: Control the moisture content of the charge to be between 9-10%; Control the copper content in the charge to be below 0.9%, and the lead content to be below 4% or below 6%; Control roasting temperature; Control the pressure in the furnace between 1.2-1.4m or 1.3-1.4m; Control the oxygen content in the furnace; The temperature inside the furnace is regulated by two sets of water jackets.

2. A method for extending the service life of a fluidized bed furnace according to claim 1, characterized in that: The lead content is below 4% for 48m 2 Fluidized bed furnaces, where the lead content is less than 6%, are used for 16m 2 Boiling furnace.

3. A method for extending the service life of a fluidized bed furnace according to claim 1, characterized in that: The controlled calcination temperature is between 980-1050°C.

4. A method for extending the service life of a fluidized bed furnace according to claim 1, characterized in that: The furnace pressure is between 1.2-1.4m for 48m 2 Fluidized bed furnace, the pressure in the furnace is between 1.3-1.4m for 16m 2 Boiling furnace.

5. A method for extending the service life of a fluidized bed furnace according to claim 1, characterized in that: The oxygen content in the furnace is controlled between 6.7-7.8%.

6. A method for extending the service life of a fluidized bed furnace according to claim 1, characterized in that: The charge is a mixture of multiple zinc concentrates or a single zinc concentrate.

7. A method for extending the service life of a fluidized bed furnace according to claim 1, characterized in that: The two groups of water jackets are respectively located in different areas of the furnace and are used to accurately control the temperature of the different areas.

8. A method for extending the service life of a fluidized bed furnace according to claim 1, characterized in that: The sulfur content of the charge is 16m 2 In the fluidized bed furnace, it is controlled below 5% to reduce scaling and corrosion in the furnace.

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