CN113957237B - Multistage preheating manganese ore reduction roasting method capable of realizing energy conservation and emission reduction and multistage preheating manganese ore reduction roasting system - Google Patents

Multistage preheating manganese ore reduction roasting method capable of realizing energy conservation and emission reduction and multistage preheating manganese ore reduction roasting system Download PDF

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CN113957237B
CN113957237B CN202111059306.0A CN202111059306A CN113957237B CN 113957237 B CN113957237 B CN 113957237B CN 202111059306 A CN202111059306 A CN 202111059306A CN 113957237 B CN113957237 B CN 113957237B
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gas
manganese ore
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manganese
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CN113957237A (en
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刘小银
陈雯
李家林
刘旭
彭泽友
陆晓苏
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Changsha Research Institute of Mining and Metallurgy Co Ltd
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B1/00—Preliminary treatment of ores or scrap
    • C22B1/02—Roasting processes
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B47/00—Obtaining manganese
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/10—Reduction of greenhouse gas [GHG] emissions
    • Y02P10/143—Reduction of greenhouse gas [GHG] emissions of methane [CH4]

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  • Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)

Abstract

The invention discloses a multistage preheating manganese ore reduction roasting method capable of realizing energy conservation and emission reduction, which takes a gas fuel with low nitrogen content as a raw material, utilizes the reaction of the gas fuel and manganese ore to carry out reduction roasting, the reaction of the gas fuel and manganese ore can realize self-heating, and the gas phase of a reaction product almost contains only CO 2 And/or H 2 O, manganese ore is manganese ore powder after multistage preheating. Correspondingly, the multistage preheating manganese ore reduction roasting system comprises a manganese ore bin, a metering and conveying device, an autothermal reducer, a roasting ore cooler, a secondary suspension preheating device and a high-temperature exhaust gas generating device; wherein the high temperature exhaust gas generating device is at least one of an autothermal reducer, a roasted mine cooler or a gaseous fuel combustion chamber. The invention has the advantages of high efficiency, economy, energy conservation, environmental protection and CO emission reduction 2 The roasting quality can be ensured, and the like.

Description

Multistage preheating manganese ore reduction roasting method capable of realizing energy conservation and emission reduction and multistage preheating manganese ore reduction roasting system
Technical Field
The invention belongs to the technical field of metallurgical mineral separation, and particularly relates to reduction roasting and CO (carbon monoxide) of manganese ores 2 An emission reduction method and system.
Background
Electrolytic manganese metal is one of the indispensable raw materials in the industries of steel, aluminum alloy, magnetic materials, chemical industry and the like. The electrolytic manganese metal industry in China mostly uses rhodochrosite (MnCO 3 ) Adopts 'H' as raw material 2 SO 4 Leaching, impurity removal and electrolysis. Because the high-grade rhodochrosite resources in China are completely consumed, the manganese grade of the rhodochrosite raw material is reduced to 10% -12% and is still difficult to succeed, so that the acid consumption in the production process is high, the slag quantity is large, the production cost is high, and the slag quantity per ton of electrolytic manganese metal is as high as 7 tons. Along with the gradual perfection of the environmental protection policy in China, the production enterprises of electrolytic manganese metal face dailyAnd the environmental protection pressure is serious. With high grade pyrolusite (MnO) 2 ) Adopts' reduction roasting → H as raw material 2 SO 4 The process of leaching, impurity removal and electrolysis is used for producing electrolytic manganese metal, so that the solid waste amount in the production of the electrolytic manganese metal can be reduced by about 70%, and meanwhile, the acid consumption in the leaching process is reduced, the impurity removal operation of the leaching liquid is simplified, and the process is a necessary trend in the production of the electrolytic manganese metal.
The key process for producing electrolytic manganese metal by using pyrolusite as raw material is to reduce and convert acid-insoluble high-valence Mn into acid-soluble Mn 2+ . The pyrolusite reduction roasting method includes rotary kiln reduction, shaft furnace reduction, fluidization reduction and the like. Recently, fluidized reduction roasting methods have been greatly developed, and a number of patents have been filed, such as: CN104878193a "a system and method for fluidization reduction roasting of low-grade manganese oxide ore", CN104911334A "a system and method for fluidization reduction of high-grade manganese dioxide ore", CN111500854A "a suspension roasting system and method for industrial treatment of ferro-manganese ore", CN101591731a "a suspension roasting comprehensive utilization system and method for ferro-manganese ore", etc., these patents disclose a method for reduction roasting of pyrolusite in a fluidized state by using gas or combustion flue gas as fluidization and reduction medium.
We have found that, due to 79% of the air being inert gas N 2 Thus, more than 60% of the tail gas generated by the combustion of the gas and the fuel is inert gas N 2 . Inert gas N 2 Is very bad due to the large number of existing: (1) Inert gas N 2 The reaction is not participated in the process, but the process needs to be subjected to an ineffective heating process of 'heating from room temperature to reduction reaction temperature-cooling from reduction reaction temperature to reasonable temperature and then discharging', a large amount of conveying power and fuel are consumed, the roasting energy consumption is greatly increased, and the process discharged CO is further increased 2 An amount of; (2) CO of tail gas of reduction roasting system 2 The concentration is about 20 percent, the separation and purification difficulty is high, and the cost is high, thus, the CO 2 Cannot be utilized, can only be discharged to the atmosphere, and does not accord with the current carbon dioxide emission reduction policy; (3) Inert gas N 2 With O in a high temperature process 2 React to generate a small amount of NO X Resulting inAdverse environmental effects; (4) The volume of the gas treated in the process is large, and the equipment and pipeline size are required to be increased, so that the construction investment is increased.
Aiming at the practical problems existing in the reduction roasting process of the manganese oxide ore at the present stage, how to comprehensively realize CO 2 The method has the advantages of emission reduction, energy conservation, consumption reduction, investment reduction and environmental pollution reduction, and has important significance for the reduction roasting process of manganese oxide ores and the subsequent production and utilization of manganese metal.
Disclosure of Invention
The invention aims to solve the technical problems of overcoming the defects and the shortcomings in the prior art and providing the high-efficiency, economical, energy-saving, environment-friendly and emission-reducing CO 2 The roasting quality can be ensured, and the multistage preheating manganese ore reduction roasting method and the multistage preheating manganese ore reduction roasting system can be realized.
In order to solve the technical problems, the technical proposal provided by the invention is a multistage preheating manganese ore reduction roasting method capable of realizing energy conservation and emission reduction, which is characterized in that a gas fuel with low nitrogen content is used as a raw material, the gas fuel is reacted with manganese ore to carry out reduction roasting, the reaction of the gas fuel and manganese ore can realize self-heating, and the gas phase of a reaction product almost contains CO 2 And/or H 2 And O, wherein the manganese ore is manganese ore powder after multistage preheating (at least two stages). The method for reducing and roasting the manganese ore is also combined with multistage preheating, and the multistage preheating treatment is carried out on the manganese ore, so that not only can the energy consumption be better saved and the temperature of the manganese ore before entering the reactor be improved, but also the subsequent full and complete reaction between the gas fuel and the manganese ore can be better ensured to realize self-heating, and the utilization rate of the gas fuel can be improved.
Further preferably, the multi-stage preheating adopts a two-stage suspension preheating mode, and the high-temperature air flow of the two-stage suspension preheating is from high-temperature exhaust gas generated after the combustion, the reduction roasting or the heat exchange of the gas fuel. The gas generated after the combustion or the reduction roasting of the gas fuel has obvious advantages, because no new impurities, no invalid gas such as nitrogen and the like are introduced, and the gas has promotion effect on the subsequent reduction roasting reaction. By carrying out contact preheating on mineral powder and tail gas generated by combustion or reduction roasting reaction, the temperature of the tail gas generated by the reaction can be reduced (the tail gas can be cooled to below 250 ℃), waste heat utilization can be realized, and heat consumption in a later-stage self-heating reducer is reduced. In addition, the gas fuel can be adopted to firstly exchange heat and absorb heat and then is introduced into the secondary suspension preheating device.
In the above method for reducing and roasting multi-stage preheated manganese ore, preferably, the gas fuel contains at least CH 4 、CO、H 2 More preferably, the gas fuel contains mainly CH 4 And contains little other gaseous components, such as natural gas itself or cracked or purified gaseous fuel; the manganese ore is mainly prepared from MnO 2 As the oxygen carrier (particularly preferred is a single pyrolusite).
When gaseous fuel and manganese ore raw materials are the aforementioned preferred materials, the following chemical reactions almost mainly occur:
CH 4 +4MnO 2 ＝4MnO+CO 2 +2H 2 O-60.16kcal/mol (1)
CO+MnO 2 ＝MnO+CO 2 -34.91kcal/mol (2)
H 2 +MnO 2 ＝MnO+H 2 O-25.06kcal/mol (3)
from the above, the reactions (1) to (3) are exothermic reactions, and the self-heating can be realized by the reduction roasting of pyrolusite by utilizing the exothermic reaction of the chemical reactions, so that the energy consumption is reduced; at the same time, the gaseous product of the above reaction contains almost only CO 2 And H 2 O, cooling the tail gas to below 100deg.C, condensing to remove water vapor to obtain high concentration CO 2 The gas being CO 2 Creates good conditions for utilization and emission reduction. And due to the absence of inert gas N 2 Not only does not produce NO during the roasting process x The process gas quantity can be greatly reduced by more than 60%, so that the gas conveying power is reduced, the volumes of equipment and conveying pipelines are reduced, the construction investment is reduced, and the economic and environment-friendly manganese ore reduction roasting process is realized. We use CH 4 Proceeding withBy taking manganese ore reduction as an example, calculating and obtaining CO produced by each ton of electrolytic manganese metal 2 The discharge amount is about 280kg/t, and compared with the production of electrolytic manganese metal by using rhodochrosite as raw material, CO 2 The discharge amount is reduced by 65 percent.
It is further preferred that the feedstock and manganese ore are subjected to reduction roasting by flameless combustion, the reduction roasting being carried out in an autothermal reducer (preferably provided with a flame detector). The flameless combustion mode can greatly reduce energy consumption and gas fuel consumption, and can reduce side reaction, so that self-heating reaction can be smoothly carried out. And the high-temperature exhaust gas generated by the reduction roasting is subjected to secondary suspension preheating, condensation and purification, and then the tail gas containing high-concentration carbon dioxide is collected.
Further preferably, the self-heating reducer is a fluidized reactor with a stepped air distribution plate in an inner cavity, a plurality of reaction areas (preferably 2-5) are divided between adjacent steps by a partition plate, manganese ore entering the self-heating reducer is firstly conveyed to a first reaction area where the highest stepped air distribution plate is located, then sequentially goes down through each reaction area where each stepped air distribution plate is located, and finally flows out of the self-heating reducer from a last reaction area where the lowest stepped air distribution plate is located. The step air distribution plate is arranged to divide the self-heating reduction roasting into a plurality of reaction areas, so that a certain residence time of mineral aggregate in the self-heating reduction device can be ensured (the preferable residence time can be controlled to be 3-50 min), and the gas fuel can be fully utilized to react completely, so that the concentration of carbon dioxide content in reaction tail gas is prevented from being influenced by inclusion of the gas fuel, and the recycling of the tail gas is further influenced. The temperature of the fluidized zone in the autothermal reducer is preferably controlled at 500℃to 900 ℃. With such an optimized configuration, mn in the feedstock in the autothermal reducer can be obtained 4+ Fully reduce to Mn 2+ Almost all of the gaseous fuel is converted to CO 2 And H 2 O; mn in the reduced roasted ore 2+ /TMn＞90％。
Further preferably, a gas fuel inlet is formed in the bottom of the self-heating reducer, a gas outlet for reaction tail gas is formed in the top of the self-heating reducer, and the reaction tail gas generated after the gas fuel sequentially passes through each reaction zone for reaction is discharged from the gas outlet;
a sensor for detecting gas and a gas diverter valve for controlling according to the detection data of the sensor are arranged near the gas outlet; when the concentration of the gas fuel collected by the sensor is less than 5 percent (generally, the volume concentration), the gas diverter valve guides the tail gas to be sent into a secondary suspension preheating device capable of preheating manganese ores; otherwise, the gas diverter valve directs the off-gas to be recycled into the reaction zone of the autothermal reducer.
The sensor is additionally arranged on the air outlet, so that the concentration of combustible gas in the reaction tail gas can be better ensured to be lower than the specified concentration, and the phenomenon that the utilization rate of the fuel and the CO of the tail gas are influenced due to the fact that gas fuel enters the reaction tail gas under abnormal working conditions is avoided 2 The recycling concentration of the catalyst can better ensure continuous production under various working conditions.
In the multistage preheating manganese ore reduction roasting method, preferably, the air inflow velocity of the gas fuel takes 0.8-1.2 times of the theoretical consumption of the manganese ore reduction reaction as a control standard; the air inlet flow rate of the gas fuel can be adjusted according to the acquired data of a flame detector and/or a sensor arranged in the reduction roasting; when the flame detector detects that flame exists or the sensor detects that the concentration of the gas fuel of the reaction tail gas is high (for example, more than 5 percent), the inlet air flow rate of the gas fuel is reduced.
By controlling the gas fuel inlet flow rate, the self-heating reaction can be better realized, and the full utilization of the gas fuel is ensured.
In the above method for reducing and roasting multi-stage preheated manganese ores, preferably, the high-temperature exhaust gas generated after heat exchange of the gas fuel refers to high-temperature exhaust gas generated by the gas fuel in an ignition or non-ignition mode after absorbing waste heat of roasted ores. If the secondary suspension preheating device is fed in a non-ignition mode, the gas fuel corresponding to heat absorption can realize the prereduction of the manganese ore in the secondary suspension preheating device, and in such a case, the temperature of the gas fuel and the temperature of the manganese ore after entering the suspension preheating device need to be properly increased. Aiming at different suspension preheating heat supply modes, different subsequent treatments can be carried out on tail gas generated by suspension preheating. The method is preferable to realize the pre-reduction of the manganese ore in the suspension preheating device by igniting or not igniting the mode of alternately supplying high-temperature exhaust gas, firstly raising the preheating temperature of the manganese ore by the ignited high-temperature exhaust gas and then directly supplying gas fuel at intervals in a non-igniting mode after absorbing heat.
According to the multistage preheating manganese ore reduction roasting method, preferably, the secondary suspension preheating mode specifically comprises the primary preheater and the secondary preheater, a gas source of high-temperature exhaust gas (namely, a high-temperature exhaust gas generating device) is communicated with the gas inlet of the secondary preheater through a conveying pipeline, manganese ore is conveyed into a pipeline connecting the gas outlet of the secondary preheater and the gas inlet of the primary preheater, is suspended in flue gas flowing out of the secondary preheater and enters the primary preheater along with gas flow, gas-solid separation and preliminary preheating are completed in the primary preheater, and manganese ore powder flowing out of the primary preheater is sent into the pipeline connecting the gas source of high-temperature exhaust gas and the gas inlet of the secondary preheater again and flows into the secondary preheater along with high-temperature exhaust gas again, so that gas-solid separation and cyclic preheating are completed in the secondary preheater. Through the two-stage circulation preheating, the investment cost of multistage suspension preheating can be reduced, and the negative influence of aerodynamic force and wind resistance in the multistage suspension preheating can be reduced, so that the rapid preheating treatment of manganese ores is realized.
In the above-described multistage-preheated manganese ore reduction roasting method, preferably, the manganese ore is required to be ground to a particle size of 1mm or less and the moisture content is controlled to 5% or less before the reduction roasting reaction is performed. By controlling the granularity and the moisture content of the raw materials before the reduction roasting reaction, the manganese ore raw materials can be better reacted completely in the self-heating reducer, and the quality of roasted ores is improved.
In the multistage preheating manganese ore reduction roasting method, preferably, the temperature of manganese ore powder after multistage preheating is controlled to be 200-800 ℃.
Further preferably, the reduction roasting is performed or the preheating is performed in multiple stagesDust collection treatment is carried out on dust-containing tail gas generated after the treatment by a dust remover, and dust obtained by the dust collection treatment is used as a reclaimed material to be combined with manganese ore and returned for reduction roasting; the purified tail gas obtained by dust collection treatment enters a condenser to be cooled in a non-contact way, the temperature of the tail gas is reduced to below 100 ℃, water vapor in the tail gas is condensed into liquid water and is separated from gas, and the residual gas is collected and then is used for preparing high-concentration CO 2 And (3) gas. Since the whole reduction roasting process of manganese ore does not have inert gas N 2 Takes part in that the generated purified tail gas almost only contains CO 2 And water vapor, cooling to below 100deg.C, condensing into liquid water, separating from gas, and collecting the rest gas as high concentration CO 2 The gas can be used as chemical raw material for sale, thereby reducing CO generated by reduction roasting of manganese ore 2 And (5) discharging.
The invention also provides a multistage preheating manganese ore reduction roasting system capable of realizing energy conservation and emission reduction, which comprises a manganese ore storage bin, a metering and conveying device, an autothermal reducer, a roasting ore cooler, a secondary suspension preheating device and a high-temperature exhaust gas generating device; the discharge port of the manganese ore bin is communicated with the feed port of the metering and conveying device; the discharge port of the metering and conveying device is communicated with the feed port of the secondary suspension preheating device; the air inlet and the discharge port of the secondary suspension preheating device are respectively communicated with the air outlet of the high-temperature discharge gas generating device and the feed inlet of the self-heating reducer; the discharge port of the self-heating reducer is connected with the roasting ore cooler; the bottom of the self-heating reducer is provided with an air inlet communicated with a gas fuel conveying system, and the gas fuel at least contains CH 4 、CO、H 2 One or more of (the gaseous fuel does not contain inert gas N) 2 Both as a reducing medium and as a fluidizing medium); the gas outlet of the self-heating reduction device is provided with a gas outlet for conveying the gas almost containing CO 2 And/or H 2 A conveying pipeline for reaction tail gas of O; the high-temperature exhaust gas generating device is at least one of the self-heating reducer, the roasting ore cooler or a gas fuel combustion chamber.
In the multistage preheating manganese ore reduction roasting system, preferably, a heat supplementing device can be additionally arranged in the self-heating reducer, and if the self-heating reaction heat is insufficient, the heat required by the reaction can be supplemented at any time through the control system so as to ensure the stability, the persistence and the continuity of the reduction roasting process.
In the above multistage pre-heating manganese ore reduction roasting system, preferably, the multistage pre-heating manganese ore reduction roasting system further comprises a dust remover and a condenser, wherein the condenser is preferably a dividing wall type cooler, and the cooling medium can be water or air. The air outlet of the secondary suspension preheating device and/or the self-heating reducer is communicated with the air inlet of the dust remover, the air outlet of the dust remover is connected with the air inlet of the condenser, and the air outlet of the condenser is connected to the process of producing high-concentration CO through an induced draft fan 2 The gas collecting device is used for further completing the dust removal, dehydration, transportation and purification of the reaction tail gas. CO of the gas collecting device 2 A portion of the gas or a gaseous fuel is fed into the calciner for cooling the reduced-roasted ore and maintaining the roasted ore in an oxygen-isolated atmosphere.
In the multistage preheated manganese ore reduction roasting system, the roasting ore cooler can be a dividing wall type cooler, and the roasting ore and the cooling medium perform non-contact heat exchange, but preferably, the CO of the gas collecting device 2 Part of the gas or gas fuel is fed into the roasting ore cooler for cooling the reduced roasted ore (for example, below 150 ℃) and maintaining the roasted ore under an oxygen-isolated atmosphere, and the gas outlet of the roasting ore cooler is further communicated with an autothermal reducer, a secondary suspension preheating device, a gas fuel combustion chamber or other raw material conveying pipelines. By part of CO 2 The gas is conveyed into the roasting ore cooler, so that CO can be realized in situ 2 The recycling of gas can prevent reoxidation of roasted ore, ensure the roasting quality of the roasted ore, and raise the temperature of CO after cooling 2 The gas can also supplement the waste heat back to the reaction system to maintain the low air concentration in the reaction system, and can further recover CO at last 2 And (3) gas. By feeding gaseous fuel gas into the calciner cooler not onlyThe utilization of the waste heat of the roasted ore can be realized, and the heat supply for suspension preheating and the prereduction of the manganese ore can be realized.
In the above multistage pre-heating manganese ore reduction roasting system, preferably, the multistage pre-heating manganese ore reduction roasting system is a device system close to a sealed environment to ensure that the leak rate of air to the multistage pre-heating manganese ore reduction roasting system is less than 5%, and air lockers are arranged on solid material conveying pipelines in the multistage pre-heating manganese ore reduction roasting system to prevent gas from moving and ensure that the gas flows according to the flow direction required by the process. In addition, by adjusting the rotating speed of the induced draft fan, the negative pressure in the equipment and the pipeline from the air outlet of the self-heating reducer to the air inlet of the induced draft fan can be further ensured, the leakage of gas and dust is prevented, the generation of clean environment is ensured, and the self-heating reducer is CO 2 The delivery of the gas provides the motive force.
According to the multistage preheating manganese ore reduction roasting system, preferably, the secondary suspension preheating device specifically comprises the primary preheater and the secondary preheater, the high-temperature exhaust gas device is communicated with the gas inlet of the secondary preheater through the conveying pipeline, manganese ore is conveyed into the pipeline connecting the gas outlet of the secondary preheater and the gas inlet of the primary preheater, the manganese ore is suspended in flue gas flowing out of the secondary preheater and enters the primary preheater along with gas flow, gas-solid separation and preliminary preheating are completed in the primary preheater, manganese ore powder flowing out of the primary preheater is sent into the pipeline connecting the high-temperature exhaust gas generating device and the gas inlet of the secondary preheater again, and flows into the secondary preheater along with high-temperature exhaust gas again, and gas-solid separation and circulating preheating are completed in the secondary preheater.
Compared with the prior art, the invention has the beneficial effects that:
1) The invention utilizes MnO 2 And CH (CH) 4 、CO、H 2 The self-heating characteristic of the reaction develops a reducing tail gas without N 2 And only contains CO 2 And H 2 In the continuous reduction roasting mode of the manganese ore of O, the reduction roasting method and the reduction roasting system have no inert gas N 2 The participation of the ineffective gas volume in the system can be reduced by more than 60 percent, and the method has the remarkable advantages that: due to self-heatingThe tail gas of the original device is only CO 2 、H 2 O and a small amount (or no) of gas fuel, and the reaction tail gas can obtain CO with the purity of at least 80 percent (preferably more than 90 percent) after condensation and dehydration 2 Gas, which is CO 2 Creates good conditions for reducing the emission and comprehensively utilizing, and can further realize CO reduction of manganese ores 2 And emission is reduced greatly.
2) The reduction roasting method and the system have the advantages that the occupation ratio of the invalid gas volume in the system is greatly reduced, so that good reaction conditions are created for the self-heating reaction, the self-heating in the roasting process can be basically realized by fully utilizing the heat release of the reaction, and the process energy consumption is greatly reduced.
3) Because the reduction roasting method and the system of the invention have no inert gas N 2 Avoiding N existing in other existing reduction roasting methods 2 The process is more energy-saving and consumption-reducing through the invalid process of 'heating from room temperature to reduction reaction temperature-cooling from the reduction reaction temperature to reasonable temperature and then discharging'; at the same time, due to the system controlling N 2 NO NO is generated upon entry of (2) x Under the conditions of (2) hardly generating NO x The process is more environment-friendly.
4) Because the reduction roasting method and the system of the invention have no inert gas N 2 On the premise of equivalent action, the gas conveying power in the system is greatly reduced, and the power consumption in the process is smaller.
5) Because the reduction roasting method and the system of the invention have no inert gas N 2 The volumes of process equipment and pipelines are reduced greatly, the construction land of process equipment is reduced, and the construction investment of a process system is reduced.
6) The reduction rate of the manganese ore of at least 90% can be obtained by optimally controlling the parameter conditions and the system operation (such as comprehensive realization of raw material control, flow control, reaction condition control and the like) of the reduction roasting process, the technical index is more advanced, and the quality of the roasted ore is easier to be ensured.
In general, the multistage preheating manganese ore reduction roasting method and system have the advantages of high efficiency, economy, energy conservation, environmental protection, Emission reduction CO 2 The advantages in all aspects, etc., are more in line with the current energy-saving and environment-friendly policy, and have important significance for the green development and utilization of manganese oxide ore resources in China.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic structural diagram and a schematic process diagram of a multistage preheated manganese ore reduction roasting system of the invention.
FIG. 2 is a schematic diagram of the internal structure of the autothermal reducer in the multi-stage pre-heated manganese ore reduction roasting system of the present invention.
Legend description:
the device comprises a 1-manganese ore bin, a 2-metering conveying device, a 3-self-heating reducer, a 31-stepped air distribution plate, a 32-partition plate, a 33-sensor, a 34-gas flow dividing valve, a 35-gas fuel air inlet, a 36-flame detector, a 4-roasting ore cooler, a 5-secondary suspension preheating device, a 6-dust remover, a 7-condenser, an 8-induced draft fan, a 9-air locking device, a 10-gas collecting device, a 11-solid material conveying pipeline, a 12-gas fuel combustion chamber, a 51-primary preheater and a 52-secondary preheater.
Detailed Description
The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments are shown, for the purpose of illustrating the invention, but the scope of the invention is not limited to the specific embodiments shown.
Unless defined otherwise, all technical and scientific terms used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the scope of the present invention.
Unless otherwise specifically indicated, the various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or may be prepared by existing methods.
The specific embodiment is as follows:
the invention discloses a multistage preheating manganese ore reduction roasting system capable of realizing energy conservation and emission reduction, which is shown in figure 1, and comprises a manganese ore storage bin 1, a metering and conveying device 2, an autothermal reducer 3, a roasting ore cooler 4 and a secondary suspension preheating device 5; the discharge port of the manganese ore bin 1 is communicated with the feed port of the metering and conveying device 2; the discharge port of the metering and conveying device 2 is communicated with the feed port of the secondary suspension preheating device 5; the air inlet of the secondary suspension preheating device 5 is communicated with the air outlet of the high-temperature exhaust gas generating device; the discharge port of the secondary suspension preheating device 5 is communicated with the feed port of the self-heating reducer 3; the discharge port of the self-heating reducer 3 is connected with a roasting ore cooler 4; the bottom of the self-heating reducer 3 is provided with an air inlet communicated with a gas fuel conveying system, and the gas fuel at least contains CH 4 、CO、H 2 One or more of the following; the gas outlet of the self-heating reducer 3 is provided with a gas outlet for conveying the gas almost containing CO only 2 And/or H 2 And a conveying pipeline for O reaction tail gas.
The high temperature exhaust gas generating means may be at least one of an autothermal reducer 3, a calciner cooler 4 or a gaseous fuel combustor 12. When the gas fuel combustion chamber 12 is selected, the gas fuel is directly mixed with air and then enters the gas fuel combustion chamber 12 to be ignited, and then the high-temperature exhaust gas is sent into the secondary suspension preheating device 5 (see a path a in fig. 1); when the autothermal reducer 3 is selected, the reaction tail gas of the autothermal reducer 3 can be directly introduced into the secondary suspension preheating device 5 (see path b in fig. 1), and the reaction tail gas temperature is cooled to below 250 ℃; when the roasting ore cooler 4 is selected, the cooled gas fuel can firstly exchange heat to absorb heat through the roasting ore cooler 4, and the absorbed gas fuel can be firstly ignited in the gas fuel combustion chamber 12 and then sent to the secondary suspension preheating device 5 (namely, the path a is equivalent), or can be directly sent to the secondary suspension preheating device 5, particularly according to the heat condition required by the secondary suspension preheating device 5 (see the path c in fig. 1). The high-temperature exhaust gas generating device of the embodiment can adopt the mode of the path a+path c at the same time, and can realize the interval replacement of the path a+path c through the control valve so as to perform the preheating treatment on mineral aggregate, and simultaneously can partially realize the pre-reduction operation and improve the efficiency of the later reaction.
As shown in fig. 2, the autothermal reducer 3 of the present embodiment is a fluidized reactor having a stepped air distribution plate 31 provided in the inner cavity, and the adjacent steps are divided into a plurality of reaction zones (3 in the present embodiment) by a partition plate 32. The step-type air distribution plate 31 is arranged to divide the self-heating reduction roasting into a plurality of reaction areas, and the conveying path of mineral aggregate in the self-heating reduction device 3 is prolonged, so that the certain residence time of the mineral aggregate in the self-heating reduction device 3 can be ensured (the residence time can be preferably controlled to be 3-60 min), the gas fuel can be fully utilized to realize complete reaction, the concentration of carbon dioxide content in reaction tail gas is prevented from being influenced by inclusion of the gas fuel, and the recycling of the tail gas is further influenced.
As shown in fig. 2, the bottom of the autothermal reducer 3 in this embodiment is provided with a gas fuel inlet 35, and the top is provided with a gas outlet for reaction tail gas, and the reaction tail gas generated after the reaction of the gas fuel in each reaction zone sequentially is discharged from the gas outlet. A sensor 33 for detecting gas and a gas diverter valve 34 controlled according to the detection data of the sensor 33 are arranged near the gas outlet; when the concentration of the combustible gas collected by the sensor 33 is less than 5%, the gas diverter valve 34 guides the tail gas to be sent to the secondary suspension preheating device 5 or directly to the dust remover 6 (in the embodiment, to the dust remover 6); otherwise, the gas diverter valve 34 directs the off-gas to be recycled into the first reaction zone of the autothermal reducer 3. The sensor 33 is additionally arranged on the air outlet, so that the reaction tail gas is better ensured not to be mixed with gas fuel, and the gas fuel is prevented from entering the reaction tail gas under abnormal working conditions, thereby influencing the utilization rate of the fuel and the CO of the tail gas 2 The recycling concentration of the catalyst can better ensure continuous production under various working conditions.
In addition, as shown in fig. 2, three reaction areas are provided in this embodiment, and three gas fuel inlets 35 may be provided correspondingly, because the reaction states of mineral aggregates facing different reaction areas may be different, unreacted mineral aggregates near the feed inlet are more and react more fully, mineral aggregates near the discharge outlet are more and react fully, and the demand for gas fuel is relatively smaller, in order to ensure that the gas fuel introduced in different reaction areas react more fully and improve the reaction efficiency, we can adjust the intake air amount and intake air rate of gas fuel in different reaction areas by controlling the feed valve and the flow control valve at the gas fuel inlet 35, so that the intake air amount and intake air rate of gas fuel near the feed inlet are properly increased, shorten the flow path of gas fuel near the discharge outlet by the baffle plate, and prolong the flow path of gas fuel near the discharge outlet by the baffle plate, so as to further improve the reaction efficiency and the sufficiency of gas fuel.
The secondary suspension preheating device 5 in this embodiment specifically includes a primary preheater 51 and a secondary preheater 52, the high-temperature exhaust gas generating device is connected to the gas inlet of the secondary preheater 52 through a conveying pipeline, the manganese ore is conveyed into the pipeline connecting the gas outlet of the secondary preheater 52 with the gas inlet of the primary preheater 51, the manganese ore is suspended in the flue gas flowing out of the secondary preheater 52 and enters the primary preheater 51 along with the gas flow, the gas-solid separation and preliminary preheating are completed in the primary preheater 51, the manganese ore powder flowing out of the primary preheater 51 is sent into the pipeline connecting the high-temperature exhaust gas generating device with the gas inlet of the secondary preheater 52 again, and flows into the secondary preheater 52 along with the high-temperature exhaust gas again, the gas-solid separation and cyclic preheating are completed in the secondary preheater 52, and finally, the manganese ore powder is sent into the self-heating reducer 3.
The autothermal reducer 3 of this embodiment is further provided with a flame detector 36 (existing detection devices such as infrared detection and image detection can be adopted), and the intake flow rate of the gaseous fuel can be adjusted according to the collected data of the flame detector 36 and/or the sensor 33; when flame detector 36 detects a flame or sensor 33 detects a high concentration of reactive tail gas combustible gas (e.g., greater than 5%), the gas fuel intake flow rate may be reduced. By controlling the gas fuel inlet flow rate, the self-heating reaction can be better realized, and the full utilization of the gas fuel is ensured.
The multistage preheating manganese ore reduction roasting system of the specific embodiment further comprises a dust remover 6 and a condenser 7, wherein the air outlet of the secondary suspension preheating device 5 is communicated with the air inlet of the dust remover 6, the air outlet of the self-heating reduction device 3 in the specific embodiment can also be directly communicated with the air inlet of the dust remover 6, the air outlet of the dust remover 6 can be connected with the air inlet of the condenser 7, and the air outlet of the condenser 7 is connected to the production of high-concentration CO through an induced draft fan 8 2 The gas collecting device 10 can directly enter the gas collecting device 10 without condensation if the water vapor content in the dust remover 6 is small.
CO of the gas collecting device 10 in this embodiment 2 Part or all of the gas can be conveyed to the roasting ore cooler 4 through a conveying pipeline for cooling the roasting ore subjected to reduction roasting and maintaining the roasting ore in an oxygen-isolated atmosphere, and the gas outlet of the roasting ore cooler 4 is communicated with the self-heating reducer 3 or the secondary suspension preheating device 5.
The multistage pre-heated manganese ore reduction roasting system of the present embodiment is a device system close to a sealed environment (i.e., the equipment, the pipes and the connection thereof in the multistage pre-heated manganese ore reduction roasting system are all required to have good sealing performance) so as to ensure that the leak rate of air into the multistage pre-heated manganese ore reduction roasting system is less than 5%. In addition, the rotation speed of the induced draft fan 8 is regulated so as to control negative pressure in equipment and pipelines from the air outlet of the self-heating reducer 3 to the air inlet of the induced draft fan 8; preventing gas and dust from leaking out, ensuring that the environment is clean and is CO 2 The delivery of the gas provides the motive force.
The solid material conveying pipelines 11 in the multistage preheating manganese ore reduction roasting system of the specific embodiment are all provided with air lockers 9.
The method for carrying out reduction roasting on manganese ores by the multistage preheating manganese ore reduction roasting system based on the specific embodiment specifically comprises the following steps (the steps are sequentially carried out according to the following step sequence in terms of single-batch mineral materials, but the steps in the operation of the system are not in sequential order and can be matched with each other to be carried out simultaneously):
s1, preparing mineral powder:
the pyrolusite is crushed, ground and dried to the granularity of 0-1 mm, the water content is less than 5%, then the pyrolusite is fed into a manganese ore bin 1, mineral powder flows out from a bottom discharge hole of the manganese ore bin 1 to a metering and conveying device 2, and the metering and conveying device 2 accurately meters and adjusts the ore feeding amount.
S2, preheating powder:
the metered manganese ore powder is conveyed into a secondary suspension preheating device 5, in particular, the manganese ore powder is conveyed into a pipeline connecting an air outlet of a secondary preheater 52 and an air inlet of a primary preheater 51, manganese ore is suspended in flue gas flowing out of the secondary preheater 52 and enters the primary preheater 51 along with gas flow, gas-solid separation and preliminary preheating are completed in the primary preheater 51, the manganese ore powder flowing out of the primary preheater 51 is conveyed into a pipeline connecting a high-temperature exhaust gas generating device and the air inlet of the secondary preheater 52 again, and flows into the secondary preheater 52 along with high-temperature exhaust gas again, gas-solid separation and cyclic preheating are completed in the secondary preheater 52, and finally the manganese ore powder is conveyed into an autothermal reducer 3 to be preheated to 200-800 ℃;
In this embodiment, the roasting ore cooler 4 is selected as the high-temperature exhaust gas generating device, the cooling gas fuel is subjected to heat exchange and heat absorption through the roasting ore cooler 4, the absorbed gas fuel can be ignited in the gas fuel combustion chamber 12 and then sent into the secondary suspension preheating device 5 (i.e. the path a in fig. 1), and also can be directly sent into the secondary suspension preheating device 5, specifically according to the heat condition required by the secondary suspension preheating device 5 (see the path c in fig. 1), the mode of the path a+path c can be adopted at the same time, and the interval replacement of the path a+path c can be realized through the control valve, so that the pre-reduction operation can be partially realized while the ore is subjected to the preheating treatment, and the efficiency of the later reaction can be improved.
S3, self-heating reduction:
the preheated mineral powder flows out of the secondary suspension preheating device 5 and enters the self-heating reducer 3, the self-heating reducer 3 is of a fluidized bed structure with a built-in stepped air distribution plate 31, and the manganese mineral powder entering the self-heating reducer 3 is firstly conveyed to the first stage where the highest stepped air distribution plate is locatedThe reaction zone (zone A) is that the gas fuel is continuously introduced into the self-heating reducer 3 from the gas fuel inlet 35 (the heat supplementing device may be needed to supplement heat in advance when the system is started for the first time), the mineral powder is suspended in the gas fuel, manganese dioxide in the mineral powder is taken as an oxygen carrier, and the manganese dioxide and the gas fuel are subjected to flameless combustion, mn 4+ Reduction to Mn 2+ Oxidation of gaseous fuels to CO 2 And H 2 O; because the reaction is exothermic, the temperature in the self-heating reducer 3 can be maintained at 500-900 ℃ by releasing heat by the reaction, and self-heating is realized in the reaction process.
In the reaction process, the inlet flow rate of the gas fuel is controlled to be 0.8 to 1.2 times (preferably more than 1.05 times) of the theoretical consumption of the reduction reaction of the manganese ore; the gas fuel is guided by the baffle plate 32 and other various baffles in the autothermal reducer 3 to be bent through each reaction zone, so as to finally realize the full and complete reaction of the gas fuel and the manganese ore.
In addition, in order to cope with abnormal conditions and ensure stable and continuous progress of the reaction, a flame detector 36 and a sensor 33 are further disposed in the autothermal reducer 3, and when the flame detector 36 detects that there is a flame or the sensor 33 detects that the concentration of the gaseous fuel in the reaction tail gas is high, the intake flow rate of the gaseous fuel can be reduced to achieve flameless combustion and complete reaction as much as possible. In addition, the gas diverter valve 34 may direct the reaction off-gas output to the secondary suspension preheating device 5 or recycled to the first reaction zone of the autothermal reducer 3 based on the data collected from the sensor 33. By controlling the gas fuel inlet flow rate, the self-heating reaction can be better realized, and the full utilization of the gas fuel is ensured.
The optimal arrangement of the present embodiment enables Mn in the raw material in the autothermal reformer 3 4+ Fully reduce to Mn 2+ Almost all of the gaseous fuel is converted to CO 2 And H 2 O; mn in the reduced roasted ore 2+ /TMn＞90％。
S4, purifying tail gas:
dust-containing tail gas flowing out of the secondary suspension preheating device 5 is subjected to dust collection treatment by adopting a dust remover 6 (a cyclone dust remover and/or a cloth bag dust remover can be selected), and the reaction tail gas of the self-heating reducer 3 is also subjected to dust collection treatment by adopting the dust remover 6; the tail gas containing dust is purified, and the reclaimed material can be combined with the manganese ore raw material and then returned into the self-heating reducer 3 for continuous reduction roasting.
S5, dehydrating tail gas:
the purified tail gas after dust removal can enter a condenser 7 for non-contact cooling (mainly aiming at the reaction tail gas of the self-heating reducer 3), the temperature is reduced to below 100 ℃, the water vapor is condensed into liquid water and separated from the gas, and the residual gas can be used for preparing high-concentration CO after being collected 2 The gas is used as raw material gas in chemical process, thereby reducing CO generated by reduction roasting of manganese ore 2 And (5) discharging. The dust-containing tail gas flowing out of the secondary suspension preheating device 5 can directly enter the gas collecting device 10 without condensation treatment.
S6, gas delivery:
the air outlet of the condenser 7 is connected with the induced draft fan 8, the rotating speed of the induced draft fan 8 is regulated, the air in the system can flow to the induced draft fan 8, the negative pressure is ensured in the equipment and the pipeline from the air outlet of the self-heating reducer 3 to the air inlet of the induced draft fan 8, the leakage of the air and dust is prevented, the environmental safety and the cleaning are ensured, and the air and the dust are CO 2 The gas delivery provides the motive force. The induced draft fan 8 can be used for converting CO 2 The gas is introduced into the gas collecting device 10.
S7, cooling the roasted ore:
the roasted ore flowing out of the self-heating reducer 3 enters the roasted ore cooler 4, the mode of combining a dividing wall type cooler with contact cooling can be selected in the specific embodiment, indirect heat exchange can be carried out between the dividing wall type cooler and cooling mediums such as water, air and the like until the temperature of the roasted ore is less than 100 ℃, the roasted ore waste heat is recovered while the reduced roasted product is cooled, the heated gas fuel is preheated, and the energy consumption of the system is reduced. In addition, it is preferable that the CO of the gas collecting device 10 2 Part of the gas can be conveyed to the roasting ore cooler 4 through a conveying pipeline for cooling the roasting ore subjected to reduction roasting and maintaining the roasting ore in an oxygen-isolated atmosphere; the air outlet of the roasting ore cooler 4 may be re-connected to the autothermal reducer 3 for re-recovery for useCooled carbon dioxide gas. The gas fuel in the present embodiment may be preferably used as a cooling medium, so that the cooling medium firstly enters the roasting ore cooler 4 to recover the waste heat of the roasting ore, and then may be directly connected to the air inlet of the secondary suspension preheating device 5 for preheating and pre-reduction treatment, and may be further connected to the gas fuel combustion chamber 12, so as to further reduce energy consumption and greatly improve the waste heat recovery utilization rate (see the flow direction of the air flow arrow shown in fig. 1 c).
From the above, the multistage preheating manganese ore reduction roasting method and system capable of realizing energy conservation and emission reduction in the embodiment can almost realize CO 2 And a large amount of other pollutants are reduced, so that the energy conservation and the consumption reduction are realized in a true sense, the pollution is reduced, the comprehensive utilization of various resources is realized, and the method has an demonstration effect on the realization of circular economy.
Example 1
Tmn=42% and Mn in pyrolusite used in this example 2+ Tmn=1.62%, high valence manganese (trivalent or tetravalent manganese) must be reduced to Mn 2+ And then the ideal leaching effect can be obtained by adopting sulfuric acid leaching.
The multistage pre-heated manganese ore reduction roasting system of the above specific embodiment is used for reduction roasting of manganese oxide ore, and mainly comprises the following steps (the following steps only list main parameters in the example, and the operation steps and equipment conditions which are not specifically described are the same as the above examples):
s1, preparing mineral powder: the pyrolusite is crushed and ground to prepare-0.074mm80% granularity mineral powder, the mineral powder is sent into a manganese mineral bin 1, and the mineral powder flows out from a discharge hole at the bottom of the manganese mineral bin 1 to a metering and conveying device 2.
S2, preheating mineral powder: the metered ore powder is fed into a secondary suspension preheating device 5, and the ore powder is preheated to 400 ℃. The heat source for preheating the mineral powder comes from gas fuel which enters a gas fuel combustion chamber 12 to ignite and discharge high-temperature gas after absorbing heat by a roasting ore cooler 4, and gas which is directly fed into the gas fuel after absorbing heat by the roasting ore cooler 4; both can be simultaneously or alternately introduced;
S3, self-heating reduction: the preheated mineral powder flows out of the secondary suspensionA floating preheating device 5 which enters the self-heating reducer 3 and contains CH in a suspended state 4 、CO、H 2 The gas fuel (preferably natural gas or methane-based gas fuel obtained after pyrolysis and purification) is reacted for 20min, and Mn in mineral powder 4+ Conversion to Mn 2+ After the gas fuel is fully consumed, CO is generated 2 And H 2 O; the self-heating in the reaction process is realized by utilizing the heat released by the reaction, and the temperature in the self-heating reducer 3 is maintained at 700 ℃; the gas fuel is introduced in an amount which is 0.98 times the theoretical consumption of the reduction reaction of the manganese ore.
S4, purifying tail gas: the reaction tail gas discharged from the self-heating reducer 3 and the dust-containing tail gas discharged from the secondary suspension preheating device 5 are purified and collected by a cyclone dust collector, and the collected dust can be recycled into the self-heating reducer 3 for continuous reduction after being used as raw material to combine manganese ore powder.
S5, dehydrating tail gas: if the water vapor content in the purified tail gas from which dust is removed is large, the tail gas can enter a condenser 7 for non-contact cooling, the temperature of the tail gas is reduced to 70 ℃, the water vapor is condensed into liquid water and separated from gas, and the residual gas is measured to be CO with the concentration of 94 percent 2 And (3) gas.
S6, gas delivery: the air outlet of the condenser 7 is connected with the air inlet of the induced draft fan 8, the rotating speed of the induced draft fan 8 is regulated to enable the air in the system to flow to the induced draft fan 8, negative pressure is ensured in equipment and pipelines from the air outlet of the self-heating reducer 3 to the air inlet of the induced draft fan 8, the leakage of air and dust is prevented, the clean environment is ensured to be generated, and the CO is purified 2 The gas is conveyed to an adjacent chemical plant to be used as raw material gas in the chemical process, so that CO generated by reducing and roasting manganese ores is realized 2 And emission is reduced greatly.
S7, cooling the roasted ore: the roasted ore flowing out of the self-heating reducer 3 enters a dividing wall type cooler to indirectly exchange heat with a water cooling medium and introduced cooling gas fuel until the temperature of the roasted ore is less than 80 ℃ to obtain a reduced roasted product, and Mn in the product 2+ /TMn＝95.3％。
The natural gas consumption of the two procedures of mineral powder suspension preheating and self-heating reduction in the reducing roasting process of the embodiment is about 1:2, and the natural gas consumption is compared with that of the conventional manganese oreComparing the reduction processes, the CO generated in the self-heating reduction process 2 As raw material gas in chemical process, and energy saving in technological process, the manganese ore reduction process of the method can reduce CO emission by more than 70 percent 2 。
The experiment in this example shows that Mn can be obtained by reducing and roasting manganese oxide ore with natural gas as a reducing agent and gas fuel 2+ The TMn is about 95% of roasted ore. The chemical reaction for preparing manganese sulfate by taking manganese oxide ore as a raw material comprises the following steps:
MnO+H 2 SO 4 ——→MnSO 4 +H 2 O
the chemical reaction formula calculates that manganese oxide ore is used as raw material to prepare manganese sulfate and ton of CO of manganese sulfate 2 The theoretical yield of (5) is 72.85kg, and compared with the process using rhodochrosite as raw material, the method can reduce CO 2 The emission was 70%. In fact, although the manganese oxide ore natural gas reduction process is an exothermic reaction, the reduction process can fully utilize the exothermic reaction, if the exothermic reaction is insufficient, only a proper heat source is needed to supplement the heat source, and CH is used as a reducing agent 4 The (natural gas) may in turn be combusted to provide heat for the reduction process.
The heat balance calculation of reduction roasting is carried out on manganese oxide ore with 40% -45% of manganese content, and the natural gas required to be combusted in the reduction process is 25Nm 3 T (natural gas consumption can be further reduced if sufficient residual heat utilization is performed), and generated CO 2 49.11kg/t. Then the manganese oxide ore is used for producing manganese sulfate, the required quantity of the manganese oxide ore is 1.29t/t, the manganese oxide ore is converted into manganese sulfate products, and CO generated by combustion is converted 2 The discharge amount was 63.34kg/t. Thus, manganese sulfate is produced by taking manganese oxide ore as raw material, and the actual CO of manganese sulfate product is unit 2 The discharge amount is 136.19kg/t (72.85+63.34); conversion to electrolytic manganese metal, actual CO 2 The discharge amount was 273.90kg/t. Compared with the production process using rhodochrosite as raw material, the method can reduce CO 2 53.26% of the emissions. Furthermore, manganese oxideMnO in ore 2 The mineral content reaches 71.18%, the impurity mineral content is only 28.82%, the manganese sulfate is produced by taking the manganese sulfate as a raw material, the waste residue amount of a ton of manganese sulfate product is 372kg, the manganese sulfate is converted into electrolytic manganese metal, the waste residue amount is 1020kg/t, and compared with the manganese ore with the manganese grade of 12% which is used as a raw material for producing the electrolytic manganese metal, the waste residue amount is reduced by more than 80%.
The production of the manganese product is carried out by taking high-grade manganese oxide ore as raw material by using 200 ten thousand tons per year of the manganese product of the wet process in China, thereby reducing solid waste and CO 2 The emission is 1100 ten thousand tons/year and 105 ten thousand tons/year respectively, and the ecological environment benefit is very obvious.
Example 2:
tmn=38% and Mn in pyrolusite used in this example 2+ Tmn=0.83%, high valence manganese (trivalent or tetravalent manganese) must be reduced to Mn 2+ And then the ideal leaching effect can be obtained by adopting sulfuric acid leaching.
The conditions for the reduction roasting were controlled to be substantially the same as those of example 1, but the gas fuel was introduced in an amount 1.1 times the theoretical amount of the reduction reaction to obtain Mn 2+ TMn is 96.8% of the reduction roasting product, and the reduction conversion effect is good.
In addition, in example 1, the sensor 33, the gas flow dividing valve 34 and the comprehensive optimization control of the gas fuel flow rate were used together, so that the finally collected gas could reach 94% CO by measurement 2 The gas, while in this embodiment, the CO in the dehydrated residual gas is condensed without activating the sensor 33, the gas diverter valve 34 and the flame detector 36 2 The concentration of the gas is 90.87 percent and the concentration of the gas fuel is 7.39 percent, and the residual gas is absorbed by alkaline solution to remove CO 2 The gas and the gas fuel can be returned for use.
As can be seen from a comparison of this example 2, the CO can be greatly increased with the sensor 33, gas diverter valve 34 and flame detector 36 activated 2 Gas collection concentration and gas fuel utilization.
The multi-stage preheating reduction roasting system of the embodiment also has significant advantages:
(1) The roasting energy consumption is low: art chargerThe exothermic heat of the reduction process is utilized, and the energy consumption of natural gas fluidization reduction roasting is only 30kgce/t (raw ore). Compared with the roasting energy consumption of the electric heating rotary kiln reduction process which is about 300kW.h/t (36.87 kgce/t of the folded standard coal), the roasting energy consumption of the natural gas fluidization reduction roasting process is reduced by 18.63%, thereby reducing CO in the reduction process 2 Discharging; compared with the suspension flash reduction roasting energy consumption of 48.94kgce/t, the roasting energy consumption of the natural gas fluidization reduction roasting process is reduced by 38.70%.
(2) The roasting tail gas can be utilized, and the tail gas can be prepared into CO with the concentration of more than 90 percent only by simple dust removal, cooling and dehydration 2 The gas can be used as chemical raw material.
(3) The processing capacity of the unit equipment is large. The unit equipment treatment capacity of the natural gas fluidization reduction roasting process can be determined according to the needs from 5 ten thousand tons/year to 100 ten thousand tons/year.
(4) The processing cost is low. The processing cost of the reduction roasting of manganese oxide ore is about 250 yuan/t (the price of natural gas is 3.5 yuan/m) by adopting the natural gas fluidization reduction roasting process 3 And does not contain raw ore cost).
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The use of terminology is for convenience in describing the particular implementations and is not intended to limit the scope of the present invention. All technical solutions belonging to the inventive concept are within the scope of the present invention, and it should be noted that, for those skilled in the art, substitutions, improvements, modifications and adjustments of the process parameters without departing from the principles of the present invention should be considered as the scope of the present invention.

Claims (11)

1. A multistage preheating manganese ore reduction roasting method capable of realizing energy conservation and emission reduction is characterized in that a gas fuel with low nitrogen content is used as a raw material, the gas fuel is utilized to react with manganese ore for reduction roasting, the reaction of the gas fuel and manganese ore can realize self-heating, and the gas phase of a reaction product only contains CO 2 And/or H 2 O, wherein the manganese ore is manganese ore powder after multistage preheatingMaterial preparation; the gas fuel is CH 4 ；
The gas fuel and manganese ore powder are subjected to reduction roasting in a flameless combustion mode, the reduction roasting is performed in an autothermal reducer (3), and high-temperature exhaust gas generated by the reduction roasting is subjected to secondary suspension preheating, condensation and purification, and then carbon dioxide-containing tail gas is collected;
the self-heating reducer (3) is a fluidization reactor with a stepped air distribution plate (31) arranged in an inner cavity, a plurality of reaction areas are separated by a partition plate (32) between adjacent steps, manganese ore powder entering the self-heating reducer (3) is firstly conveyed to a first reaction area where the highest stepped air distribution plate is located, then sequentially goes down through each reaction area where each stepped air distribution plate is located, and finally flows out of the self-heating reducer (3) from a last reaction area where the lowest stepped air distribution plate is located; a flame detector (36) is also arranged in the self-heating reducer (3);
The bottom of the self-heating reducer (3) is provided with a gas fuel inlet (35), the top of the self-heating reducer is provided with a gas outlet of reaction tail gas, and the reaction tail gas generated after the gas fuel sequentially passes through each reaction zone for reaction is discharged from the gas outlet;
a sensor (33) for detecting the gas fuel is arranged near the gas outlet, and a gas diverter valve (34) is controlled according to the detection data of the sensor (33); when the concentration of the gas fuel collected by the sensor (33) is less than 5%, the gas diverter valve (34) guides the tail gas to be sent into a secondary suspension preheating device (5) capable of preheating manganese ores; otherwise, the gas diverter valve (34) directs the off-gas to be recycled into the reaction zone of the autothermal reducer (3).
2. The method for reducing and roasting multi-stage preheated manganese ore according to claim 1, wherein the multi-stage preheating adopts a two-stage suspension preheating mode, and the high-temperature air flow of the two-stage suspension preheating is from high-temperature exhaust gas generated after the reduction roasting or heat exchange of the gas fuel.
3. The multistage preheated manganese ore reduction roasting according to claim 2The method is characterized in that the manganese ore is treated with MnO 2 As oxygen carrier.
4. The multistage preheated manganese ore reduction roasting method according to claim 1, wherein the inlet flow rate of the gas fuel is controlled to be 0.8-1.2 times of the theoretical consumption of the manganese ore reduction reaction; and the intake flow rate of the gaseous fuel can be adjusted according to the collected data of a flame detector (36) and/or a sensor (33) arranged in the reduction roasting.
5. The method for reducing and roasting the multistage preheated manganese ores according to any one of claims 2 to 4, wherein the secondary suspension preheating mode specifically comprises a primary preheater (51) and a secondary preheater (52), a gas source of high-temperature exhaust gas is communicated with a gas inlet of the secondary preheater (52) through a conveying pipeline, the manganese ores are conveyed into a pipeline connecting a gas outlet of the secondary preheater (52) and the gas inlet of the primary preheater (51), the manganese ores are suspended in flue gas flowing out of the secondary preheater (52) and enter the primary preheater (51) along with gas flow, gas-solid separation and preliminary preheating are completed in the primary preheater (51), manganese ore powder flowing out of the primary preheater (51) is sent into the pipeline connecting the gas source of high-temperature exhaust gas and the gas inlet of the secondary preheater (52) again, and then enters the secondary preheater (52) again along with the high-temperature exhaust gas, and gas-solid separation and cyclic preheating are completed in the secondary preheater (52).
6. The multi-stage pre-heated manganese ore reduction roasting method according to any one of claims 1 to 4, wherein the manganese ore is required to be ground to a particle size of 1mm or less and the moisture content is controlled to be 5% or less before the reduction roasting reaction is performed; and the temperature of the manganese ore powder after multistage preheating reaches 200-800 ℃.
7. The multistage preheated manganese ore reduction roasting method according to any one of claims 1 to 4, wherein the dust-containing tail gas produced after the reduction roasting or after the multistage preheating treatment is subjected to dust removal by a dust remover (6)Dust collection treatment, wherein dust obtained by the dust collection treatment is taken as a reclaimed material to be returned again for the reduction roasting; the purified tail gas obtained by dust collection treatment enters a condenser (7) for non-contact cooling to reduce the temperature to below 100 ℃, water vapor in the purified tail gas is condensed into liquid water and separated from gas, and the residual gas is used for preparing CO after being collected 2 And (3) gas.
8. A multistage pre-heated manganese ore reduction roasting system used in the multistage pre-heated manganese ore reduction roasting method capable of realizing energy saving and emission reduction according to any one of claims 1 to 7, wherein the multistage pre-heated manganese ore reduction roasting system comprises a manganese ore storage bin (1), a metering and conveying device (2), an autothermal reducer (3), a roasting ore cooler (4), a secondary suspension pre-heating device (5) and a high-temperature exhaust gas generating device; the discharge port of the manganese ore bin (1) is communicated with the feed port of the metering and conveying device (2); the discharge port of the metering and conveying device (2) is communicated with the feed port of the secondary suspension preheating device (5); the air inlet and the discharge port of the secondary suspension preheating device (5) are respectively communicated with the air outlet of the high-temperature exhaust gas generating device and the feed inlet of the self-heating reducer (3); the discharge port of the self-heating reducer (3) is connected with the roasting ore cooler (4); the bottom of the self-heating reducer (3) is provided with an air inlet communicated with a gas fuel conveying system, and the gas fuel is CH 4 The method comprises the steps of carrying out a first treatment on the surface of the The gas outlet of the self-heating reducer (3) is provided with a device for conveying CO only 2 And/or H 2 A conveying pipeline for reaction tail gas of O;
the high-temperature exhaust gas generating device is at least one of the self-heating reducer (3) or the roasting ore cooler (4).
9. The multistage pre-heated manganese ore reduction roasting system according to claim 8, further comprising a dust remover (6) and a condenser (7), wherein the air outlet of the secondary suspension pre-heating device (5) and/or the self-heating reducer (3) is communicated with the air inlet of the dust remover (6), and the dust remover is a part of the whole plant6) The air outlet is connected with the air inlet of the condenser (7), and the air outlet of the condenser (7) is connected to the production of CO through an induced draft fan (8) 2 A gas collecting device (10) for collecting gas;
CO of the gas collecting device (10) 2 And part of gas or gas fuel is conveyed into the roasting ore cooler (4) for cooling the roasting ore subjected to reduction roasting and maintaining the roasting ore in an oxygen-isolated atmosphere, and the gas outlet of the roasting ore cooler (4) is communicated with the self-heating reducer (3), the secondary suspension preheating device (5) or other raw material conveying pipelines.
10. The multistage pre-heating manganese ore reduction roasting system according to claim 8 or 9, wherein the multistage pre-heating manganese ore reduction roasting system is a device system close to a sealed environment so as to ensure that the leakage rate of air into the multistage pre-heating manganese ore reduction roasting system is less than 5%, and the rotation speed of a draught fan (8) is regulated so as to control negative pressure in equipment and pipelines from the air outlet of the self-heating reducer (3) to the air inlet of the draught fan (8); and air lockers (9) are arranged on solid material conveying pipelines (11) in the multistage preheating manganese ore reduction roasting system.
11. The multistage preheating manganese ore reduction roasting system according to claim 8 or 9, wherein the secondary suspension preheating device (5) specifically comprises a primary preheater (51) and a secondary preheater (52), the high-temperature exhaust gas generating device is communicated with the gas inlet of the secondary preheater (52) through a conveying pipeline, manganese ore is conveyed into the pipeline connecting the gas outlet of the secondary preheater (52) and the gas inlet of the primary preheater (51), manganese ore is suspended in flue gas flowing out of the secondary preheater (52) and enters the primary preheater (51) along with gas flow, gas-solid separation and preliminary preheating are completed in the primary preheater (51), manganese ore powder flowing out of the primary preheater (51) is sent into the pipeline connecting the high-temperature exhaust gas generating device and the gas inlet of the secondary preheater (52) again, and flows into the secondary preheater (52) along with high-temperature exhaust gas again, and gas-solid separation and cyclic preheating are completed in the secondary preheater (52).
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5270022A (en) * 1992-09-14 1993-12-14 Paramount Sinters Private Limited Process for the reduction roasting of manganese ores and a device therefor
CN102363837A (en) * 2011-11-14 2012-02-29 中国科学院过程工程研究所 Fluidized low-temperature reduction device and reduction method for powdery manganese oxide ores
CN104833208A (en) * 2015-05-28 2015-08-12 北京四维天拓技术有限公司 Multi-bed linkage fluidized bed roasting furnace
CN108165730A (en) * 2017-12-05 2018-06-15 中信大锰矿业有限责任公司大新锰矿分公司 The method for producing manganese monoxide using sawdust reduction roasting manganese oxide ore
CN108239700A (en) * 2018-03-07 2018-07-03 长沙矿冶研究院有限责任公司 A kind of coal base fluidization reduction roasting system and its method of roasting

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106868292B (en) * 2017-03-31 2018-04-06 东北大学 A kind of refractory iron ore multistage suspension magnetizing roast magnetic separation system device and method

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5270022A (en) * 1992-09-14 1993-12-14 Paramount Sinters Private Limited Process for the reduction roasting of manganese ores and a device therefor
CN102363837A (en) * 2011-11-14 2012-02-29 中国科学院过程工程研究所 Fluidized low-temperature reduction device and reduction method for powdery manganese oxide ores
CN104833208A (en) * 2015-05-28 2015-08-12 北京四维天拓技术有限公司 Multi-bed linkage fluidized bed roasting furnace
CN108165730A (en) * 2017-12-05 2018-06-15 中信大锰矿业有限责任公司大新锰矿分公司 The method for producing manganese monoxide using sawdust reduction roasting manganese oxide ore
CN108239700A (en) * 2018-03-07 2018-07-03 长沙矿冶研究院有限责任公司 A kind of coal base fluidization reduction roasting system and its method of roasting

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