Titanium concentrate drying and flue gas treatment system

Abstract

The invention discloses a titanium concentrate drying and flue gas treatment system, and relates to the technical field of titanium concentrate production. According to the invention, the temperature of the dried flue gas is increased, and heating equipment and energy consumption cost in the denitration process are saved; the flue gas heat exchanger is additionally arranged after the denitration procedure, redundant heat is used for providing high-temperature gas for the heat supplier, and energy and fuel loss are reduced; a cyclone and bag-type dust collector in the traditional process is replaced by the high-temperature metal filter bag dust collector, so that the dust collection efficiency is high, and the equipment maintenance cost is reduced; in addition, the dedusting ash is recycled and matched with high-grade titanium concentrate to form qualified-grade titanium concentrate, and the benefit is increased; the desulfurizer is sodium hydroxide, so that the discharge of solid waste is reduced. And the energy consumption is reduced, and the production cost is saved.

Description

Technical Field

[0001] The invention relates to the technical field of titanium concentrate production, and in particular to a titanium concentrate drying and flue gas treatment system. Background Art

[0002] The conventional design of flue gas treatment system in titanium concentrate production is that the tail gas temperature after titanium concentrate drying is 120℃, cyclone + bag dust collector is used for dust removal, then wet desulfurization process is used for desulfurization, heating denitrification process is used for denitrification, and the tail gas temperature is increased to 280℃-300℃ before denitrification, and finally the purified flue gas is discharged. This design system increases energy consumption and requires an additional heating system, which increases production costs.

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

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

[0005] The present invention is achieved in that:

[0006] In a first aspect, an embodiment of the present invention provides a titanium concentrate drying and flue gas treatment system, the titanium concentrate drying and flue gas treatment system comprising a dryer and a flue gas treatment system; the flue gas treatment system comprising 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] Among them, 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; 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 by the embodiment of the present invention adopts a high-temperature metal filter bag dust collector to replace the cyclone + bag dust collector of the traditional process, which has high dust removal efficiency, reduces equipment maintenance costs, and thus saves production costs; the low-grade titanium concentrate collected by the high-temperature metal filter bag dust collector and the high-grade titanium concentrate output by the dryer are combined in the packaging device to form a qualified grade of titanium concentrate, which is conducive to increasing profits. The flue gas treatment system first denitrates the dried flue gas, and then performs heat exchange and air supply, reducing equipment and energy consumption, and achieving the purpose of reducing costs and increasing efficiency for enterprises. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

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

[0012] Figure 2 A schematic flow chart of a flue gas treatment system in titanium concentrate production provided in the first embodiment.

[0013] Icons: 1-heater; 101-first inlet of heater; 102-second inlet of heater; 103-third inlet of heater; 104-exit of heater; 2-feeding device; 201-inlet of feeding device; 202-exit of feeding device; 3-dryer; 301-first inlet of dryer; 302-second inlet of dryer; 303-first outlet of dryer; 304-second outlet of dryer; 4-first dust removal device; 401-inlet of first dust removal device; 402-first outlet of first dust removal device; 403-second outlet of first dust removal device; 5-SCR denitration process; 501-inlet of SCR denitration process; 502-exit of SCR denitration process; 6-flue gas heat exchanger; 601-flue gas heat exchanger The first inlet of the flue gas heat exchanger; 602-the second outlet of the flue gas heat exchanger; 603-the second inlet of the flue gas heat exchanger; 604-the first outlet of the flue gas heat exchanger; 7-fan; 701-fan inlet; 702-fan outlet; 8-flue gas desulfurization process; 801-flue gas desulfurization process inlet; 802-the first outlet of the flue gas desulfurization process; 803-the second outlet of the flue gas desulfurization process; 9-the second dust removal device; 901-the inlet of the second dust removal device; 902-the first outlet of the second dust removal device; 903-the second outlet of the second dust removal device; 10-chimney; 1001-chimney inlet; 11-packing device; 1101-the first inlet of the packing device; 1102-the second inlet of the packing device; 12-concentration tank; 13-solid waste treatment process. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0015] In the first aspect, an embodiment of the present invention provides 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] Among them, 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 fan inlet 701; the fan outlet 702 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 chimney inlet 1001; 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 also 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 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 provided with a first inlet, a second inlet and a second outlet, wherein the first inlet 301 of the dryer is connected to the heater outlet 104; the second inlet 302 of the dryer is connected to the feeding device outlet 202; the first outlet 303 of the dryer is connected to the first dust removal device inlet 401; the second outlet 304 of the dryer is connected to the first inlet 1101 of the packaging device, for conveying high-grade finished titanium concentrate.

[0019] In an optional embodiment of the present invention, the temperature of the flue gas 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 dried fuel; the second inlet 102 of the heater is connected to the flue gas heat exchanger 6, and is used to transport the high-temperature gas generated from the flue gas heat exchanger 6; the third inlet 103 of the heater is connected to the SCR denitrification process outlet 502, and is used to transport the high-temperature gas generated from the SCR denitrification process 5.

[0021] The specific type of the heater 1 is selected as a hot air furnace or a boiling furnace according to actual needs. The specification of the pipe connected thereto is φ2.8m×18m in an optional embodiment of the present invention. In other embodiments, the pipe specification can be reasonably adjusted according to actual needs.

[0022] It should be noted that the high-temperature gas generated by the SCR denitration process 5 and the high-temperature gas generated by the flue gas heat exchanger 6 are respectively recovered to the heater 1 for recycling, and the main purpose is:

[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 recycled and used to preheat the drying equipment or other process, thereby reducing energy consumption.

[0024] (2) Environmental protection: Drying flue gas may contain harmful substances, such as particulate matter, sulfur dioxide, nitrogen oxides, etc. By recycling flue gas, the emission of these harmful substances can be reduced, thereby reducing pollution to the environment.

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

[0026] The high-temperature gas is recovered to the heater 1 for recycling, which has the following characteristics:

[0027] (1) High thermal energy utilization rate: Drying flue gas recycling technology can efficiently recycle the heat energy in the flue gas, avoiding the waste of heat energy.

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

[0029] (3) Reduce production costs: Flue gas recycling 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 demand.

[0031] (5) Promote sustainable development: Flue gas recycling technology is in line with the concept of sustainable development. It lays the foundation for the long-term development of the enterprise by improving resource utilization and reducing environmental pollution.

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

[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 the 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 conveys the semi-finished titanium concentrate through the feeding conveyor. The present invention does not specifically limit the specific model, width and length of the feeding conveyor. Specifically, in the embodiment of the present invention, the feeding conveyor is specifically composed of two conveyors of TD75 type B650 mm×30m, which convey the semi-finished titanium concentrate to the dryer 3. In other embodiments of the present invention, reasonable adjustments and replacements can be made according to the actual production line and the amount of material processed.

[0035] In an optional embodiment of the present invention, the dryer 3 is composed of a boiling furnace and a hot air furnace arranged in parallel; the dryer 3 is matched and connected with the boiling furnace or the hot air furnace in the heater 1; wherein the fuel of the boiling furnace in the dryer 3 is biomass particles, and the fuel of the hot air furnace in the dryer 3 is natural gas.

[0036] It should be noted that the boiling furnace and the hot blast furnace in the present invention adopt a one-in-use and one-in-standby mode. If one of the devices fails, the other device is immediately activated to ensure the smooth progress 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 titanium concentrate of qualified grade; the packaging device 11 is provided with a first inlet, a second inlet and an outlet.

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

[0039] It should be noted that the dust ash produced by the first dust removal device 4 in the embodiment of the present invention is a low-grade finished titanium concentrate, and the TiO2 grade of the titanium concentrate in the dust ash is 45%-45.5%; the dust ash 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 a qualified grade titanium concentrate, and the qualified grade titanium concentrate is output from the outlet of the packaging device 11.

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

[0041] It should be noted that the moisture content in titanium concentrate directly affects the weight and volume of titanium concentrate, which in turn affects the stability of titanium concentrate, as well as the transportation and storage costs. Specifically, the higher the moisture content, the greater the weight and volume of the titanium concentrate, leading to higher transportation costs. In addition, titanium concentrate with high moisture content tends to absorb 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 high-temperature metal filter bag dust collector is used to replace the traditional cyclone + bag dust collector, which has high dust removal efficiency and reduces equipment maintenance costs.

[0043] In an optional embodiment of the present invention, a reducing agent is also delivered to the inlet 401 of the first dust removal device. The reducing agent is sprayed into the flue gas flow and reacts with NO in the flue gas under the action of the catalyst. x The reaction generates nitrogen (N2) and water (H2O), thereby reducing NO x The purpose of discharge. 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 first dust removal device inlet 401 from the first outlet 303 of the dryer is controlled to be 300°C. This operation can save the equipment and energy consumption costs of using a burner to increase the exhaust gas temperature from 120°C to 300°C during denitrification in the traditional denitrification process.

[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 is composed of a reductant system (storage, transportation, 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 and automatic control system), etc.

[0046] The second outlet 403 of the first dust removing device and the first inlet 1101 of the packing device are used to transport the dust removed to the packing device 11 .

[0047] It should be noted that the present invention places the SCR denitration process 5 after the high-temperature metal filter bag dust collector, and the flue gas enters the reactor in the denitration reaction system to remove NO x , and is sucked away by the fan 7. In the embodiment of the present invention, a temperature measurement system is added to the inlet and outlet of the SCR denitration process 5, and an automatic denitration control system is introduced.

[0048] Specifically, in an optional embodiment of the present invention, a vanadium-titanium medium-temperature catalyst (250°C-280°C) and a honeycomb vanadium-titanium catalyst are selected, the main active ingredient is V2O5, the catalyst is assisted to become WO3, and the carrier is TiO2; the catalyst can operate under any normal load of the drying furnace and fluidization; the flue gas passes vertically downward through the catalytic block layer; the flue gas flow rate in the catalyst channel is about 6m / s-7m / s; the catalyst is arranged in a 3-layer mode, and the interlayer height of the catalyst support beam is not less than 3.0 meters; the single catalyst replacement time does not exceed 72 hours; the chemical life is 30,000h, and the mechanical life is not less than 5 years.

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

[0050] Specifically, the SCR denitration process outlet 502 is connected to the third inlet 103 of the heater, so that a part of the high-temperature gas produced by the SCR denitration process 5 is directly recycled and utilized, thereby improving the heat utilization rate, reducing pollutant emissions and lowering production costs.

[0051] In addition, the SCR denitration process outlet 502 is also connected to the first inlet 601 of the flue gas heat exchanger. The flue gas heat exchanger 6 is added after the SCR denitration process 5 to exchange the temperature of another part of the high-temperature gas generated by the SCR denitration process 5 from 270°C to 120°C. The excess heat is transported from the second outlet 602 of the flue gas heat exchanger to the heater 1 to heat the blast 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, and the fan 7 is used to quickly extract the gas in the flue gas heat exchanger 6 to ensure the smooth progress of the production process and avoid corrosion of the tail flue and chimney 10 and environmental pollution. By extracting the flue gas through the fan 7, it can be ensured that the flue gas will not stagnate in the system, thereby reducing the corrosion problem caused by the condensation of acidic substances in the flue gas. At the same time, by controlling the flow of flue gas, the thermal efficiency of the entire system can be improved, energy waste can be reduced, and it helps to reduce the emission of pollutants, thereby reducing the impact on the environment. At the same time, through the suction effect of the fan 7, a certain negative pressure state is formed in the flue gas heat exchanger 6 and its upstream equipment, which helps to prevent harmful gases from leaking into the working environment and ensure 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 of the flue gas.

[0053] The flue gas heat exchanger 6 has a second outlet connected to the second inlet of the heater 1, so as 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 by the SCR denitrification process 5 or the high-temperature gas generated by the flue gas heat exchanger 6 is the recovery and utilization of waste heat in the flue gas; the transportation of high-temperature gas increases 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 desulfurizer used in the liquid alkali wet desulfurization process is sodium hydroxide.

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

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

[0058] It should be noted that in an optional embodiment of the present invention, the desulfurizing agent used is sodium hydroxide, and the tailings concentrate produced in 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 to reduce the discharge of solid waste.

[0059] The traditional process uses limestone gypsum as a desulfurization agent. The reaction process consumes a lot of energy. For example, limestone production, gypsum crystallization, calcium oxide cooling and other links all consume a lot of electricity and heat energy, which not only increases the production cost of the enterprise, but also has a certain impact on the environment. In addition, the limestone gypsum method as a desulfurization agent will produce a large amount of waste residue, which contains various harmful substances and is difficult to reuse. Improper treatment will have a great impact on the environment and also requires a certain amount of capital 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 for treating dust from the liquid output from the first outlet 802 of the flue gas desulfurization process.

[0061] It should be noted that the wet electrostatic precipitator has the characteristics of low energy consumption and easy operation; its dust removal efficiency can reach more than 90%, showing its efficient dust removal ability; in addition, the wet electrostatic precipitator also has the characteristics of small size, simple and compact structure, small footprint and low price, and is an ideal equipment for controlling atmospheric dust pollution.

[0062] The first outlet 902 of the second dust removal device is connected to the chimney inlet 1001 for discharging 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 concentration tank 12 together, and then enter the solid waste treatment process 13 for unified treatment.

[0063] It should be noted that the height of the chimney 10 should meet the requirements of the comprehensive emission standards for air pollutants, not only meet the prescribed emission rate standard value, but also ensure that it is at least 5 meters higher than the surrounding buildings within a radius of 200 meters. The structural design of the chimney 10 is reasonably adjusted and designed according to the actual use conditions, functional requirements, material supply and construction conditions.

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

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

[0066] Specifically, the flue gas temperature discharged from the chimney 10 is less than 50°C, NO x Content ≤50mg / Nm 3 , SO2 content ≤35mg / Nm 3 , particle content ≤50g / Nm 3 , VOC x Content ≤15mg / Nm 3 .

[0067] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0068] First embodiment

[0069] This embodiment provides a titanium concentrate drying and flue gas treatment system. Figure 2 The working principle is described in detail:

[0070] The drying fuel is heated by the heater 1 (boiling furnace), and the heated flue gas (temperature 950°C) is transported into the dryer 3 from the first inlet 301 of the dryer, and the semi-finished titanium concentrate is sent into the dryer 3 from the second inlet of the dryer 3 through the feeding device 2, wherein the flue gas (temperature 300°C) is output from the first outlet 303 of the dryer, and is sent to the first dust removal device 4 through the first dust removal device inlet 401; the high-grade finished titanium concentrate (temperature <90°C) obtained in the dryer 3 is output from the second outlet 304 of the dryer, and is transported to the packaging device 11 through the second inlet 1102 of the packaging device, and is mixed with the dust removal ash (low-grade titanium concentrate) output from the second outlet 403 of the first dust removal device in proportion to form a titanium concentrate of qualified grade, which is packaged and output. It should be noted that in this embodiment, ammonia water with a mass concentration of 10% is also transported at the inlet 401 of the first dust removal device as a reducing agent.

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

[0072] The flue gas (temperature is 290°C) output from the first outlet 402 of the first dust removal device enters the SCR denitrification process 5 through the SCR denitrification process inlet 501 for denitrification treatment; a part of the high-temperature flue gas (temperature 270°C) after denitrification enters the boiling furnace from the third inlet of the heater 1 through the action of the induced draft fan 7, which is used to provide heat for the boiling furnace; the other part enters the flue gas heat exchanger 6 through the first inlet 601 of the flue gas heat exchanger for heat exchange treatment with the blast (i.e., room temperature air), and the high-temperature gas (120°C) after heat exchange is output from the second inlet of the heater 1 through the second outlet 602 of the flue gas heat exchanger to enter the boiling furnace, which is used to provide heat for the boiling furnace; the flue gas (temperature ≤120°C) 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 from 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 desulfurizer used is flaky 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°C) output from the first outlet 802 of the flue gas desulfurization process is sent to the second dust removal device 9 through the second dust removal device inlet 901 for dust treatment, and 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 need to heat the flue gas coming out of 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), thereby eliminating the combustion heating equipment and energy consumption costs. The cost savings are specifically shown in Table 1 (calculated according to natural gas heating). It should be noted that the cost will fluctuate according to the actual unit price and usage of natural gas.

[0075] Table 1

[0076] Cost (10,000 yuan) / year Unit consumption (yuan / ton) <![CDATA[Natural gas consumption (m 3 / h)]]> 181.29 4.53222 70

[0077] In addition, 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 recycled, 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 for use as make-up air, thereby saving energy and reducing the equipment and energy loss for heating the make-up air (room temperature air) in the heater 1. Specifically, the heat exchange power saved is 1100Kw / h.

[0078] In summary, the titanium concentrate drying and flue gas treatment system provided in the embodiment of the present invention increases the temperature of the flue gas after drying, thereby eliminating the 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 loss; a high-temperature metal filter bag dust collector is used to replace the cyclone + bag dust collector of the traditional process, with high dust removal efficiency and reduced equipment maintenance costs; in addition, the dust ash is recycled and combined with high-grade titanium concentrate to form a qualified grade titanium concentrate, which is beneficial to increasing profits; the desulfurizer is sodium hydroxide to reduce the emission of solid waste.

[0079] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope 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 includes 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; Among them, 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 denitration process; the outlet of the SCR denitration 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; The first dust removal device is a high-temperature metal filter bag dust collector.

2. The titanium concentrate drying and flue gas treatment system according to claim 1, characterized in that: The titanium concentrate drying and flue gas treatment system also includes a heater and a feeding device; the heater is used to provide heat to the drying fuel; the feeding device is used to transport the semi-finished titanium concentrate into the dryer; The dryer is also provided with a first inlet and a second inlet, wherein the first inlet of the dryer is communicated with the outlet of the heater; and the second inlet of the dryer is communicated with the outlet of the feeding device.

3. The titanium concentrate drying and flue gas treatment system according to claim 2, characterized in that: The titanium concentrate drying and fume treatment system further comprises a packaging device, which is used for packaging and transporting titanium concentrate of qualified grade; The dryer is also provided with a second outlet, which is connected to the first inlet of the packaging device and is used for conveying high-grade finished titanium concentrate.

4. The titanium concentrate drying and flue gas treatment system according to claim 2, characterized in that: The heater is also provided with a first inlet, a second inlet and a third inlet; wherein the first inlet of the heater is used for conveying dried fuel; the second inlet of the heater is connected to the flue gas heat exchanger, and is used for conveying high-temperature gas generated from the flue gas heat exchanger; the third inlet of the heater is connected to the outlet of the SCR denitration process, and is used for conveying high-temperature gas generated from the SCR denitration process.

5. The titanium concentrate drying and flue gas treatment system according to claim 1, characterized in that: The drying machine is composed of a boiling furnace and a hot air furnace which are arranged in parallel.

6. The titanium concentrate drying and flue gas treatment system according to claim 1, characterized in that: The first dust removal device is also provided with a second outlet; the second outlet of the first dust removal device is connected to the second inlet of the packaging device, and is used to transport dust generated by the first dust removal device; the dust is low-grade finished titanium concentrate; The dust removal ash is combined with the high-grade finished titanium concentrate in the packaging device to form titanium concentrate of qualified grade.

7. The titanium concentrate drying and flue gas treatment system according to claim 1, characterized in that: A reducing agent is also delivered to the inlet of the first dust removal device; The reducing agent is aqueous ammonia with a mass concentration of 8%-12%.

8. The titanium concentrate drying and flue gas treatment system according to claim 1, characterized in that: The flue gas desulfurization process adopts a liquid alkali wet desulfurization process; the desulfurizer used in the liquid alkali wet desulfurization process is sodium hydroxide.

9. The titanium concentrate drying and flue gas treatment system according to claim 1, characterized in that: The second dust removal device is a wet electrostatic precipitator, which is used to treat dust from the material output from the first outlet of the flue gas desulfurization process.

10. The titanium concentrate drying and flue gas treatment system according to claim 1, characterized in that: The titanium concentrate drying and flue gas treatment system also includes a monitoring device, which monitors SO2, NO x The concentration changes can be monitored in real time to control the amount of desulfurizer and denitrifier added.

Images