Titanium concentrate drying and flue gas treatment system

Abstract

The application discloses a titanium concentrate drying and flue gas treatment system and relates to the technical field of titanium concentrate production. The application increases the temperature of the dried flue gas, saves the heating equipment in the denitration process and energy consumption cost; a flue gas heat exchanger is additionally arranged after the denitration process, and the excessive heat is used to provide high-temperature gas for the heater, thereby saving energy and fuel consumption; the high-temperature metal filter bag dust collector is adopted to replace the traditional process of cyclone + bag dust collector, the dust removal efficiency is high, and the equipment maintenance cost is reduced; in addition, the dust removal ash is recycled and matched with high-grade titanium concentrate to form qualified-grade titanium concentrate, which is beneficial to improving the income; the desulfurizer is sodium hydroxide, so that the solid waste emission is reduced. While reducing the energy consumption, the production cost is saved.

Description

Technical Field

[0001] This invention relates to the field of titanium concentrate production technology, and more specifically, to a titanium concentrate drying and flue gas treatment system. Background Technology

[0002] The conventional design of a flue gas treatment system in titanium concentrate production involves using a cyclone + bag filter for dust removal at the tail gas temperature of 120℃ after titanium concentrate drying, followed by wet desulfurization and heated denitrification. Before denitrification, the tail gas temperature is raised to 280℃-300℃, and finally, the purified flue gas is discharged. This design increases energy consumption and requires an additional heating system, thus increasing production costs.

[0003] In view of this, the present invention is proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a titanium concentrate drying and flue gas treatment system to solve the above-mentioned technical problems.

[0005] This invention is implemented as follows:

[0006] In a first aspect, embodiments of the present invention provide a titanium concentrate drying and flue gas treatment system, the titanium concentrate drying and flue gas treatment system including a dryer and a flue gas treatment system; the flue gas treatment system includes a first dust removal device, an SCR denitrification process, a flue gas heat exchanger, a fan, a flue gas desulfurization process, a second dust removal device, and a chimney.

[0007] Specifically, the first outlet of the dryer is connected to the inlet of the first dust removal device; the first outlet of the first dust removal device is connected to the inlet of the SCR denitrification process; the outlet of the SCR denitrification process is connected to the first inlet of the flue gas heat exchanger; the first outlet of the flue gas heat exchanger is connected to the inlet of the fan; the outlet of the fan is connected to the first inlet of the flue gas desulfurization process; the first outlet of the flue gas desulfurization process is connected to the inlet of the second dust removal device; the outlet of the second dust removal device is connected to the inlet of the chimney; and the first dust removal device is a high-temperature metal filter bag dust collector.

[0008] The present invention has the following beneficial effects:

[0009] The titanium concentrate drying and flue gas treatment system provided in this invention uses a high-temperature metal bag filter dust collector to replace the traditional cyclone + bag filter dust collector, resulting in higher dust removal efficiency, reduced equipment maintenance costs, and thus savings in production costs. The low-grade titanium concentrate collected by the high-temperature metal bag filter dust collector is combined with the high-grade titanium concentrate output from the dryer in a packaging device to form qualified titanium concentrate, which helps improve profitability. The flue gas treatment system first denitrates the dried flue gas before heat exchange and makeup air treatment, reducing equipment and energy consumption, achieving the goal of cost reduction and efficiency improvement for enterprises. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the flue gas treatment system in conventional titanium concentrate production.

[0012] Figure 2 This is a schematic diagram of the flue gas treatment system in titanium concentrate production provided in the first embodiment.

[0013] Icons: 1-Heater; 101-Heater First Inlet; 102-Heater Second Inlet; 103-Heater Third Inlet; 104-Heater Outlet; 2-Feeding Device; 201-Feeding Device Inlet; 202-Feeding Device Outlet; 3-Dryer; 301-Dryer First Inlet; 302-Dryer Second Inlet; 303-Dryer First Outlet; 304-Dryer Second Outlet; 4-First Dust Collector; 401-First Dust Collector Inlet; 402-First Dust Collector First Outlet; 403-First Dust Collector Second Outlet; 5-SCR Denitrification Process; 501-SCR Denitrification Process Inlet; 502-SCR Denitrification Process Outlet; 6-Flue Gas Heat Exchanger; 601-Flue Gas Heat Exchanger 602 - First inlet of flue gas heat exchanger; 603 - Second inlet of flue gas heat exchanger; 604 - First outlet of flue gas heat exchanger; 7 - Fan; 701 - Fan inlet; 702 - Fan outlet; 8 - Flue gas desulfurization process; 801 - Flue gas desulfurization process inlet; 802 - First outlet of flue gas desulfurization process; 803 - Second outlet of flue gas desulfurization process; 9 - Second dust removal device; 901 - Second dust removal device inlet; 902 - First outlet of second dust removal device; 903 - Second outlet of second dust removal device; 10 - Chimney; 1001 - Chimney inlet; 11 - Packing device; 1101 - First inlet of packing device; 1102 - Second inlet of packing device; 12 - Thickening tank; 13 - Solid waste treatment process. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0015] In a first aspect, embodiments of the present invention provide a titanium concentrate drying and flue gas treatment system, which includes a dryer 3 and a flue gas treatment system; the flue gas treatment system includes a first dust removal device 4, an SCR denitrification process 5, a flue gas heat exchanger 6, a fan 7, a flue gas desulfurization process 8, a second dust removal device 9, and a chimney 10.

[0016] Specifically, the first outlet 303 of the dryer is connected to the inlet 401 of the first dust removal device; the first outlet 402 of the first dust removal device is connected to the inlet 501 of the SCR denitrification process; the outlet 502 of the SCR denitrification process is connected to the first inlet 601 of the flue gas heat exchanger; the first outlet 604 of the flue gas heat exchanger is connected to the inlet 701 of the fan; the outlet 702 of the fan is connected to the first inlet of the flue gas desulfurization process 8; the first outlet 802 of the flue gas desulfurization process is connected to the inlet 901 of the second dust removal device; the outlet of the second dust removal device 9 is connected to the inlet 1001 of the chimney; and the first dust removal device 4 is a high-temperature metal filter bag dust collector.

[0017] In an optional embodiment of the present invention, the titanium concentrate drying and flue gas treatment system further includes a heater 1 and a feeding device 2; the heater 1 is used to provide heat to the drying fuel; the feeding device 2 is used to transport the semi-finished titanium concentrate; further, the semi-finished titanium concentrate is input from the feeding device inlet 201 and transported to the dryer 3 via the feeding device 2.

[0018] The dryer 3 is also equipped with a first inlet, a second inlet, and a second outlet. The first inlet 301 of the dryer is connected to the outlet 104 of the heater; the second inlet 302 of the dryer is connected to the outlet 202 of the feeding device; the first outlet 303 of the dryer is connected to the inlet 401 of the first dust removal device; and the second outlet 304 of the dryer is connected to the first inlet 1101 of the packaging device, which is used to transport high-grade finished titanium concentrate.

[0019] In an optional embodiment of the present invention, the flue gas temperature from the heater 1 is as high as 950°C, and the heater outlet 104 is connected to the first inlet 301 of the dryer.

[0020] In an optional embodiment of the present invention, the heater 1 is further provided with a first inlet, a second inlet and a third inlet; wherein, the first inlet 101 of the heater is used to transport drying fuel; the second inlet 102 of the heater is connected to the flue gas heat exchanger 6 and is used to transport high-temperature gas generated from the flue gas heat exchanger 6; the third inlet 103 of the heater is connected to the outlet 502 of the SCR denitrification process and is used to transport high-temperature gas generated from the SCR denitrification process 5.

[0021] The specific type of heater 1 can be selected as a hot air furnace or a fluidized bed furnace according to actual needs. In the optional embodiment of the present invention, the pipe specifications are φ2.8m×18m. In other embodiments, the pipe specifications can be reasonably adjusted according to actual needs.

[0022] It should be noted that the main purpose of recovering the high-temperature gas generated in the SCR denitrification process 5 and the high-temperature gas generated in the flue gas heat exchanger 6 to the heater 1 for reuse is as follows:

[0023] (1) Energy saving and emission reduction: The flue gas generated during the drying process usually contains a large amount of heat energy. Through flue gas recycling technology, this heat energy can be effectively recovered and utilized for preheating drying equipment or other processes, thereby reducing energy consumption.

[0024] (2) Environmental protection: The drying flue gas may contain harmful substances such as particulate matter, sulfur dioxide, and nitrogen oxides. By reusing the flue gas, the emission of these harmful substances can be reduced, thereby mitigating environmental pollution.

[0025] (3) Improve economic efficiency: Flue gas reuse can reduce the energy costs of enterprises, improve resource utilization, and thus enhance the economic efficiency of enterprises.

[0026] The high-temperature gas is recovered and reused in heater 1, which has the following characteristics:

[0027] (1) High thermal energy utilization rate: The drying flue gas reuse technology can efficiently recover and utilize the thermal energy in the flue gas, avoiding the waste of thermal energy.

[0028] (2) Reduce pollutant emissions: By reusing flue gas, the emissions of pollutants generated during the drying process can be significantly reduced, which is conducive to improving environmental quality.

[0029] (3) Reduce production costs: Flue gas reuse can reduce the company's energy consumption and environmental protection costs, thereby reducing production costs.

[0030] (4) Improve production efficiency: Flue gas recycling technology can optimize the drying process, improve production efficiency, and enable enterprises to better meet market demands.

[0031] (5) Promote sustainable development: Flue gas reuse technology is in line with the concept of sustainable development. By improving resource utilization and reducing environmental pollution, it lays the foundation for the long-term development of enterprises.

[0032] It should be noted that in practical applications, high-temperature flue gas reuse technology can be achieved by installing equipment such as flue gas waste heat recovery systems and flue gas purification systems. These devices can effectively collect, process, and utilize the heat energy and other resources in the flue gas, thereby achieving the goals of energy conservation, emission reduction, environmental protection, and improved economic efficiency.

[0033] In an optional embodiment of the present invention, the outlet 202 of the feeding device is connected to the second inlet of the dryer 3 for conveying semi-finished titanium concentrate. The TiO2 grade of the titanium concentrate in the semi-finished titanium concentrate is 46%-47%, and the moisture content is 7.5%.

[0034] Specifically, the feeding device 2 transports semi-finished titanium concentrate via a feeding conveyor. This invention does not impose specific limitations on the model, width, and length of the feeding conveyor. In a specific embodiment of this invention, the feeding conveyor consists of two TD75 type B650 mm × 30 m conveyors, which transport the semi-finished titanium concentrate to the dryer 3. In other embodiments of this invention, adjustments and replacements can be made reasonably according to the actual production line and the amount of material processed.

[0035] In an optional embodiment of the present invention, the dryer 3 consists of a fluidized bed furnace and a hot air furnace arranged in parallel; the dryer 3 is matched and connected to the fluidized bed furnace or the hot air furnace in the heater 1; wherein, the fuel for the fluidized bed furnace in the dryer 3 is biomass pellets, and the fuel for the hot air furnace in the dryer 3 is natural gas.

[0036] It should be noted that the fluidized bed furnace and hot air furnace in this invention adopt a one-in-one standby mode. If one of the devices fails, the other device will be activated immediately to ensure the smooth operation of the production process.

[0037] In an optional embodiment of the present invention, the titanium concentrate drying and flue gas treatment system further includes a packaging device 11, which is used to package and transport qualified titanium concentrate; the packaging device 11 has a first inlet, a second inlet and an outlet.

[0038] The first inlet 1101 of the packaging device is connected to the second outlet 304 of the dryer and is used to transport high-grade finished titanium concentrate with a TiO2 grade of 46%-47%. The second inlet of the packaging device 11 is connected to the second outlet 403 of the first dust removal device and is used to transport the dust generated by the first dust removal device 4.

[0039] It should be noted that the dust generated by the first dust removal device 4 in this embodiment of the invention is low-grade finished titanium concentrate, and the TiO2 grade of the titanium concentrate in the dust is 45%-45.5%. The dust and the high-grade finished titanium concentrate output from the second outlet 304 of the dryer are combined in proportion in the packaging device 11 to form qualified titanium concentrate, and the qualified titanium concentrate is output from the outlet of the packaging device 11.

[0040] In an optional embodiment of the present invention, the grade of titanium concentrate in the qualified grade titanium concentrate is >46% and the moisture content is <0.5%.

[0041] It should be noted that the moisture content of titanium concentrate directly affects its weight and volume, thus impacting its stability and transportation and storage costs. Specifically, higher moisture content increases both the weight and volume of the titanium concentrate, leading to higher transportation costs. Furthermore, titanium concentrate with high moisture content is prone to absorbing moisture during storage, increasing storage difficulty and costs.

[0042] In an optional embodiment of the present invention, the first dust removal device 4 is a high-temperature metal filter bag dust collector, and the dust collector and its frame are made of 316L stainless steel. The use of a high-temperature metal filter bag dust collector to replace the traditional cyclone + bag dust collector results in high dust removal efficiency and reduced equipment maintenance costs.

[0043] In an optional embodiment of the present invention, a reducing agent is also supplied to the inlet 401 of the first dust removal device. The reducing agent is injected into the flue gas stream and reacts with NO in the flue gas under the action of a catalyst. x The reaction produces nitrogen gas (N2) and water (H2O), thereby reducing NO levels. x The purpose of the emission. The reducing agent is ammonia water with a mass concentration of 8%-12%; further, the reducing agent is ammonia water with a mass concentration of 10%.

[0044] In an optional embodiment of the present invention, the temperature of the flue gas entering the inlet 401 of the first dust removal device from the first outlet 303 of the dryer is controlled to be 300°C. This operation can save the equipment and energy consumption costs required by the traditional denitrification process to raise the exhaust gas temperature from 120°C to 300°C using a burner.

[0045] In an optional embodiment of the present invention, the first outlet 402 of the first dust removal device is connected to the inlet 501 of the SCR denitrification process; the SCR denitrification process 5 consists of a reducing agent system (storage, conveying, evaporation, injection system, etc.), a denitrification reaction system (reactor, catalyst, soot blowing system), a flue gas heat exchange system (plate heat exchanger, blower 7, supporting pipelines and other equipment and structural components, as well as an automatic control system).

[0046] The second outlet 403 of the first dust removal device and the first inlet 1101 of the packaging device are used to transport the dust removal ash to the packaging device 11.

[0047] It should be noted that in this invention, the SCR denitrification process 5 is placed after the high-temperature metal filter bag dust collector, and the flue gas enters the reactor of the denitrification reaction system to remove NO. x The nitrate is drawn away by the blower 7. In embodiments of the present invention, temperature measurement systems are added to the inlet and outlet of the SCR denitrification process 5, and an automatic denitrification control system is introduced.

[0048] Specifically, in optional embodiments of the present invention, a vanadium-titanium-based medium-temperature catalyst (250℃-280℃) is selected, a honeycomb vanadium-titanium catalyst, the main active component is V2O5, the catalyst promoter is WO3, and the support is TiO2; the catalyst can operate under any normal load in a drying furnace or fluidized bed; the flue gas passes vertically downward through the catalyst block layer; the flue gas velocity in the catalyst channel is about 6m / s-7m / s; the catalyst is arranged in a 3-layer pattern, and the interlayer height of the catalyst support beam is not less than 3.0 meters; the catalyst replacement time does not exceed 72 hours; the chemical life is 30,000 hours, and the mechanical life is not less than 5 years.

[0049] In an optional embodiment of the present invention, part of the high-temperature gas generated in the SCR denitrification process 5 enters the fluidized bed furnace from the third inlet of the heater 1 through the action of the induced draft fan 7 to provide heat to the fluidized bed furnace; the other part enters the flue gas heat exchanger 6 through the first inlet 601 of the flue gas heat exchanger to exchange heat with the blower air (i.e., room temperature air), wherein the blower air enters the flue gas heat exchanger 6 through the second inlet 603 of the flue gas heat exchanger.

[0050] Specifically, the outlet 502 of the SCR denitrification process is connected to the third inlet 103 of the heater, which directly recovers and reuses a portion of the high-temperature gas produced by the SCR denitrification process 5, thereby improving heat utilization efficiency, reducing pollutant emissions, and lowering production costs.

[0051] In addition, the SCR denitrification process outlet 502 is also connected to the first inlet 601 of the flue gas heat exchanger. A flue gas heat exchanger 6 is added after the SCR denitrification process 5 to exchange the temperature of another part of the high-temperature gas generated in the SCR denitrification process 5 from 270°C to 120°C. The excess heat is transferred from the second outlet 602 of the flue gas heat exchanger to the heater 1 to heat the blower of the heater 1, thereby saving energy and reducing fuel consumption.

[0052] It should be noted that the first outlet 604 of the flue gas heat exchanger is connected to the fan inlet 701. The fan 7 is used to quickly extract the gas from the flue gas heat exchanger 6, ensuring the smooth operation of the production process and avoiding corrosion of the tail flue and chimney 10, as well as environmental pollution. Extracting the flue gas by the fan 7 ensures that the flue gas does not stagnate in the system, thereby reducing corrosion problems caused by the condensation of acidic substances in the flue gas. Simultaneously, controlling the flow of flue gas improves the thermal efficiency of the entire system, reduces energy waste, and helps reduce pollutant emissions, thus mitigating the environmental impact. Furthermore, the suction effect of the fan 7 creates a certain negative pressure in the flue gas heat exchanger 6 and its upstream equipment, helping to prevent harmful gases from leaking into the working environment and ensuring the health and safety of operators. The fan outlet 702 is connected to the first inlet of the flue gas desulfurization process 8 for desulfurization treatment of the flue gas.

[0053] The flue gas heat exchanger 6 has a second outlet connected to the second inlet of the heater 1, which is used to transport the high-temperature gas after heat exchange to the heater 1 for recycling.

[0054] It should be noted that the high-temperature gas generated in the SCR denitrification process 5 or the high-temperature gas generated in the flue gas heat exchanger 6 is a recovery and utilization of the waste heat in the flue gas; the transportation of the high-temperature gas raises the temperature of the gas entering the heater 1 from room temperature to above 120°C, saving energy, reducing fuel consumption and lowering investment costs.

[0055] In an optional embodiment of the present invention, the flue gas desulfurization process 8 adopts a liquid alkali wet desulfurization process; the desulfurizing agent used in the liquid alkali wet desulfurization process is sodium hydroxide.

[0056] The flue gas from the flue gas heat exchanger 6 is drawn by the fan 7 and enters the desulfurization absorption tower in the flue gas desulfurization process 8 through the inlet 801. The flue gas rises in the desulfurization absorption tower and passes through the dust removal and desulfurization efficiency enhancement tray, the spray layer, and the high-efficiency demister in sequence before being discharged from the outlet of the flue gas desulfurization process 8. However, efficiency improvement or enhancement measures should be taken in the desulfurization absorption tower, and relevant equipment and facilities should be installed.

[0057] Specifically, the flue gas desulfurization process 8 includes a flue gas system, a flue gas cooling device, an SO2 absorption system, a slurry preparation system, an oxidation fan system, a process water system, an emergency slurry system, and a power distribution and control system.

[0058] It should be noted that, in an optional embodiment of the present invention, sodium hydroxide is used as the desulfurizing agent, and the tailings concentrate generated during the desulfurization process is transported to the concentration tank 12 through the second outlet 803 of the flue gas desulfurization process for recycling and treatment, thereby reducing the emission of solid waste.

[0059] Traditional lime-gypsum desulfurization processes, which use limestone-gypsum as a desulfurizing agent, consume a significant amount of energy. Steps such as limestone production, gypsum crystallization, and calcium oxide cooling all require substantial amounts of electricity and heat. This not only increases production costs for enterprises but also has a negative environmental impact. Furthermore, the lime-gypsum method generates large quantities of waste residue containing various harmful substances that are difficult to reuse. Improper disposal can cause significant environmental damage and also requires substantial financial investment.

[0060] In an optional embodiment of the present invention, the first outlet 802 of the flue gas desulfurization process is connected to the inlet 901 of the second dust removal device, wherein the second dust removal device 9 is a wet electrostatic precipitator, which is used to treat the liquid output from the first outlet 802 of the flue gas desulfurization process for dust removal.

[0061] It should be noted that wet electrostatic precipitators are characterized by low energy consumption and simple operation; their dust removal efficiency can reach over 90%, demonstrating their high dust removal capacity; in addition, wet electrostatic precipitators are also characterized by small size, simple and compact structure, small footprint, and low price, making them ideal equipment for controlling atmospheric dust pollution.

[0062] The first outlet 902 of the second dust removal device is connected to the inlet 1001 of the chimney and is used to discharge the final flue gas. The dust removal waste liquid output from the second outlet 903 of the second dust removal device and the material output from the second outlet 803 of the flue gas desulfurization process enter the thickening tank 12 together, and then enter the solid waste treatment process 13 for unified treatment.

[0063] It should be noted that the height of chimney 10 should meet the requirements of the integrated emission standards for air pollutants. It must not only comply with the prescribed emission rate standards but also ensure that it is at least 5 meters higher than buildings within a 200-meter radius. The structural design of chimney 10 should be reasonably adjusted and designed based on actual usage conditions, functional requirements, material supply, and construction needs.

[0064] In an optional embodiment of the present invention, the chimney 10 is a steel chimney 10 with a top elevation of 30m.

[0065] In an optional embodiment of the present invention, the titanium concentrate drying and flue gas treatment system further includes a monitoring device, which monitors SO and NO in the flue gas. x The concentration changes are monitored in real time to control the amount of desulfurizer and denitrifier added.

[0066] Specifically, the temperature of the flue gas emitted from chimney 10 is <50℃, NO x Content ≤50mg / Nm 3 SO2 content ≤35mg / Nm 3 Particulate matter content ≤50g / Nm 3 VOC x Content ≤15mg / Nm 3 .

[0067] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0068] First Embodiment

[0069] This embodiment provides a titanium concentrate drying and flue gas treatment system, which is described below in conjunction with... Figure 2 A detailed explanation of its working principle:

[0070] The drying fuel is heated by heater 1 (fluidized bed furnace), and the heated flue gas (temperature 950℃) is conveyed into dryer 3 from the first inlet 301. Simultaneously, semi-finished titanium concentrate is fed into dryer 3 from the second inlet 2 via feeder 2. Flue gas (temperature 300℃) exits from the first outlet 303 of dryer and passes through the first dust removal device inlet 401 for first dust removal device 4. High-grade finished titanium concentrate (temperature <90℃) obtained in dryer 3 exits from the second outlet 304 of dryer and is conveyed to packaging device 11 via the second inlet 1102. It is then mixed with dust (low-grade titanium concentrate) exiting from the second outlet 403 of the first dust removal device in a specific ratio to form qualified-grade titanium concentrate, which is then packaged and output. It should be noted that in this embodiment, 10% ammonia water is also conveyed at the first dust removal device inlet 401 as a reducing agent.

[0071] It should be noted that the TiO2 grade of the semi-finished titanium concentrate is 46%-47%, and the moisture content is 7.5%; the TiO2 grade of the high-grade finished titanium concentrate is 46%-47%; and the TiO2 grade of the qualified titanium concentrate is >46%, and the moisture content is <0.5%.

[0072] The flue gas (temperature 290℃) output from the first outlet 402 of the first dust removal device enters the SCR denitrification process 5 through the inlet 501 of the SCR denitrification process for denitrification treatment; the high-temperature flue gas (temperature 270℃) after denitrification, part of it enters the fluidized bed furnace from the third inlet of the heater 1 through the action of the induced draft fan 7 to provide heat to the fluidized bed furnace; the other part enters the flue gas heat exchanger 6 through the first inlet 601 of the flue gas heat exchanger to exchange heat with the blower air (i.e., room temperature air), and the high-temperature gas (120℃) after heat exchange is sent from the second outlet 602 of the flue gas heat exchanger to the second inlet of the heater 1 to enter the fluidized bed furnace to provide heat to the fluidized bed furnace; the flue gas (temperature ≤120℃) output from the first outlet 604 of the flue gas heat exchanger is extracted by the fan 7 and enters the flue gas desulfurization process 8 through the first inlet of the flue gas desulfurization process 8 for desulfurization treatment. It should be noted that the flue gas desulfurization process 8 in this embodiment adopts a wet desulfurization process, and the desulfurizing agent used is flake sodium hydroxide. The tailings concentrate after desulfurization is transported from the second outlet 803 of the flue gas desulfurization process to the concentration tank 12 for recovery, and finally enters the solid waste treatment process 13 for unified treatment.

[0073] The material (temperature 50℃) output from the first outlet 802 of the flue gas desulfurization process is sent to the second dust removal device 9 through the inlet 901 of the second dust removal device for dust treatment. The flue gas after dust removal is discharged from the chimney 10 through the outlet of the second dust removal device 9.

[0074] The titanium concentrate drying and flue gas treatment system provided in this embodiment does not require heating the flue gas from the first dust removal device 4 before the SCR denitrification process 5 (increasing the flue gas temperature from 120°C in the traditional process to 300°C), thus eliminating the need for combustion heating equipment and energy consumption costs. The specific cost savings are shown in Table 1 (calculated based on natural gas heating). It should be noted that these costs may fluctuate depending on the actual unit price and usage of natural gas.

[0075] Table 1

[0076] Cost (ten thousand yuan) / year Unit consumption (yuan / ton) <![CDATA[Natural gas consumption (m 3 / h)]]> 181.29 4.53222 70

[0077] Furthermore, in the titanium concentrate drying and flue gas treatment system provided in this embodiment, the waste heat of the flue gas heat exchanger 6 is recovered and utilized. That is, the high-temperature gas (120°C) after heat exchange is transported to the heater 1 through the second outlet 602 of the flue gas heat exchanger as makeup air for use, which saves energy and reduces the equipment and energy consumption for heating the makeup air (room temperature air) in the heater 1 section. Specifically, the heat exchange power saved is 1100Kw / h.

[0078] In summary, the titanium concentrate drying and flue gas treatment system provided in this embodiment of the invention increases the temperature of the dried flue gas, eliminating the need for heating equipment and energy consumption costs in the denitrification process; a flue gas heat exchanger 6 is added after the denitrification process, and the excess heat is used to provide high-temperature gas to the heater 1, saving energy and fuel consumption; a high-temperature metal filter bag dust collector is used to replace the traditional cyclone + bag dust collector, resulting in high dust removal efficiency and reduced equipment maintenance costs; in addition, the dust is recovered and combined with high-grade titanium concentrate to form qualified-grade titanium concentrate, which is beneficial to improving profitability; sodium hydroxide is used as the desulfurizing agent to reduce solid waste emissions.

[0079] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A titanium concentrate drying and flue gas treatment system, characterized in that, The titanium concentrate drying and flue gas treatment system comprises a dryer and a flue gas treatment system. The flue gas treatment system comprises a first dust removal device, an SCR denitration process, a flue gas heat exchanger, a fan, a flue gas desulfurization process, a second dust removal device and a chimney. The first outlet of the dryer is in communication with the inlet of the first dust removal device; the first outlet of the first dust removal device is in communication with the inlet of the SCR denitration process; the outlet of the SCR denitration process is in communication with the first inlet of the flue gas heat exchanger; the first outlet of the flue gas heat exchanger is in communication with the inlet of the fan; the outlet of the fan is in communication with the first inlet of the flue gas desulfurization process; the first outlet of the flue gas desulfurization process is in communication with the inlet of the second dust removal device; and the outlet of the second dust removal device is in communication with the inlet of the chimney. The first dust removal device is a high-temperature metal filter bag dust remover. The titanium concentrate drying and flue gas treatment system further comprises a heater and a feeding device. The heater is further provided with a first inlet, a second inlet and a third inlet; the first inlet of the heater is used for conveying drying fuel; the second inlet of the heater is in communication with the flue gas heat exchanger and is used for conveying high-temperature gas generated from the flue gas heat exchanger; and the third inlet of the heater is in communication with the outlet of the SCR denitration process and is used for conveying high-temperature gas generated from the SCR denitration process. The heater is used for providing heat for the drying fuel; and the feeding device is used for conveying semi-finished titanium concentrate into the dryer. The dryer is further provided with a first inlet and a second inlet; the first inlet of the dryer is in communication with the outlet of the heater; and the second inlet of the dryer is in communication with the outlet of the feeding device.

2. The titanium concentrate drying and flue gas treatment system of claim 1, wherein, The titanium concentrate drying and flue gas treatment system further comprises a packing device which is used for packing qualified-grade titanium concentrate. The dryer is further provided with a second outlet; the second outlet of the dryer is in communication with the first inlet of the packing device and is used for conveying high-grade finished titanium concentrate.

3. The titanium concentrate drying and flue gas treatment system of claim 1, wherein, The dryer is composed of a fluidized bed furnace and a hot blast furnace which are arranged side by side.

4. The titanium concentrate drying and flue gas treatment system of claim 1, wherein, The first dust removal device is further provided with a second outlet; the second outlet of the first dust removal device is in communication with the second inlet of the packing device and is used for conveying dust removal ash generated from the first dust removal device; and the dust removal ash is low-grade finished titanium concentrate. The dust removal ash and the high-grade finished titanium concentrate in the packing device are combined to form qualified-grade titanium concentrate.

5. The titanium concentrate drying and flue gas treatment system of claim 1, wherein, The first dust removal device is further conveyed with a reducing agent at the inlet. The reducing agent is ammonia water with a mass concentration of 8%-12%.

6. The titanium concentrate drying and flue gas treatment system of claim 1, wherein, The flue gas desulfurization process adopts a liquid alkali wet desulfurization process; and the desulfurizer used in the liquid alkali wet desulfurization process is sodium hydroxide.

7. The titanium concentrate drying and flue gas treatment system of claim 1, wherein, The second dust removal device is a wet-type electric dust collector which is used for dust treatment of the material output from the first outlet of the flue gas desulfurization process.

8. The titanium concentrate drying and flue gas treatment system of claim 1, wherein, The titanium concentrate drying and flue gas treatment system further comprises a monitoring device that monitors the concentration of SO2 and NO x in the flue gas in real time, thereby controlling the amount of desulfurizing agent and denitrating agent added.

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