Method and device for step-by-step fluidized reduction of iron and manganese in high-crystal-water ferromanganese ore

Abstract

Step-by-step fluidized reduction treatment is adopted for the high-crystal-water ferromanganese ore, firstly, the high-crystal-water ferromanganese ore is fed into a first furnace tube, first reducing gas is introduced into the first furnace tube, iron minerals in the high-crystal-water ferromanganese ore and the first reducing gas are subjected to a reduction reaction, and Fe2O3 is reduced into Fe3O4; and then cooling and magnetically separating the material discharged from the first furnace tube to obtain iron ore magnetic concentrate, feeding non-magnetic manganese mineral into a second furnace tube for reduction, carrying out reduction reaction on the manganese mineral and second reducing gas introduced into the second furnace tube to reduce MnO2 into MnO, and cooling to obtain a MnO reduction product. According to the method, the difference of reduction reaction conditions of iron and manganese compounds of the high-crystal-water ferromanganese ore is utilized, two-step fluidized reduction is performed, the first step is used for reducing iron ore, and the second step is used for reducing manganese ore, so that the problem of insufficient manganese element reduction conditions or excessive iron element reduction conditions in one-step reduction in the prior art is effectively avoided; and comprehensive recovery of iron and manganese elements can be realized.

Description

Technical Field

[0001] The present invention relates to a method and device for reducing iron and manganese in ferromanganese ore, and in particular to a step-by-step fluidized reduction method and device for iron and manganese in high-crystallization-water ferromanganese ore, belonging to the technical field of ferromanganese ore metallurgy. Background Art

[0002] During geological formation, manganese and iron often coexist closely due to their similar chemical properties, and some exhibit isomorphism. Among my country's manganese ore resources, as much as 73% contain excessive iron concentrations (m(Mn) / m(Fe) ≥ 6). High-iron manganese ore (Mn / Fe ≤ 3) accounts for 35.18%, while ferromanganese ore (Mn / Fe ≤ 1) reserves also reach tens of millions of tons. This resource is often rich in crystal water and is primarily distributed in Hunan, Guizhou, Chongqing, and Guangxi. Manganese in high-crystallization-water ferromanganese ore occurs primarily as pyrolusite and psilomelane, while iron mostly occurs as limonite. The primary gangue components are quartz, clay, and chalcedony. The ore is well-crystalline, densely structured, and often presents in massive or granular forms. Therefore, strengthening research on the beneficiation and smelting technology of high-crystallization-water ferromanganese ore is of vital practical significance to addressing the current supply and demand situation of my country's ferromanganese ore resources.

[0003] At present, there are three main methods for processing high-crystalline hydrometallurgical ferromanganese ore: mineral processing, pyrometallurgy and hydrometallurgy.

[0004] (1) Ore dressing method

[0005] The beneficiation process for highly crystalline hydroferromanganese ore generally uses a combination of several beneficiation methods: jig-wet high-intensity magnetic separation, high-intensity magnetic separation-flotation-gravity separation, high-intensity magnetic roughing separation-jigging concentrator-high-intensity magnetic sweeping separation, etc. The beneficiation of highly crystalline hydroferromanganese ore strictly requires its particle size, ore mud content, and ore magnetic properties. Because the density and specific magnetic susceptibility of the iron and manganese compounds in the ore are similar, and the two often coexist closely and have a fine embedded particle size, the beneficiation process is more complicated. It is difficult to obtain high-quality manganese and iron concentrates using conventional flotation, gravity separation, and high-intensity magnetic separation methods. At the same time, there is also the problem of serious manganese loss in the ore mud.

[0006] (2) Pyrometallurgy

[0007] Pyrometallurgical processing of high-crystallization-water ferromanganese ores is well established in my country, and is often used to treat difficult-to-separate, low-grade manganese ores with high iron and phosphorus content. However, pyrometallurgical processing of ferromanganese ores suffers from incomplete iron and manganese separation, substandard pyrometallurgical equipment that fails to meet process requirements (such as throat congestion, short smelting cycles, high slag volumes, and cooling difficulties), and high production costs.

[0008] (3) Hydrometallurgy

[0009] Hydrometallurgical treatment of highly crystalline ferromanganese ore primarily involves the production of sulfate using sulfide, ferrous salts, SO2, and other reducing organic compounds as reducing agents. In addition to the common drawbacks of conventional chemical leaching of manganese ore, its main drawbacks are high iron concentration, the need for large amounts of acid, severe environmental pollution, and difficulty in recovering metallic iron. Furthermore, the theoretical processes and mechanisms of chemical beneficiation of highly crystalline ferromanganese ore remain underdeveloped, making industrial application difficult.

[0010] The fluidized reduction of high-crystallization water iron manganese ore has gradually become a common technology in the existing technology. Fluidization refers to the process in which solid particles are in a fluid state under the action of a fluid medium. The fluidization process makes the material have liquid-like properties. Its advantages are: (1) the particle distribution is relatively dispersed, the gas-solid contact is more complete, and the product quality is stable and uniform; (2) the reaction intensity is high, the speed is fast, the mass and heat transfer effect during the chemical reaction is good, and the energy consumption is low; (3) the air flow and temperature distribution are uniform, easy to control, and the degree of automation is high; (4) the equipment has few operating parts, easy to adjust, and low maintenance costs.

[0011] Many domestic research institutes have conducted extensive research on fluidized reduction roasting equipment and technology. The Changsha Research Institute of Mining and Metallurgy has conducted research on the fluidized magnetic roasting of dozens of iron ores, achieving excellent process indicators. Using a complete set of flash magnetic roasting technology and equipment, a mixed ore with a raw grade of 32.52% iron ore can achieve an iron concentrate grade of 57.52% and an iron recovery rate of 90.24% in industrial production. This has opened up a new path for the development and utilization of complex and difficult-to-separate iron ores in my country. The Institute of Process Engineering of the Chinese Academy of Sciences used a fluidized bed reactor as a magnetic roasting device and a mixture of N2 and CO as the reducing gas to investigate the factors affecting the magnetic roasting and magnetic separation of oolitic hematite from a region in Yunnan at 550-800°C. The results show that when the unpretreated ore powder is separated by magnetic roasting and magnetic separation, the iron grade in the concentrate can be increased to about 55%, and the iron recovery rate is <70%; after pretreatment, the iron grade in the concentrate can be increased to 60.18%, and the iron recovery rate reaches 85.91%. The pretreated ore powder forms a porous and loose structure, which makes it easy for reducing gas to enter the interior of the iron ore particles, which is conducive to the formation of Fe3O4 and improves the magnetic separation index.

[0012] Manganese ore is a scarce resource in my country. The country's manganese ore resources are scarce, and the ore grade is low, failing to meet domestic demand for manganese-based products. The main reason for the recent rise in electrolytic manganese prices is that domestic manganese ore riches have been largely depleted, leading to a sharp decline in resource supply. While my country possesses a considerable amount of manganese ore, the ore grade is low, and a large proportion of iron-manganese mixed ore with high crystal water content makes its development and utilization challenging. High-crystallization-water ferromanganese ore has the chemical formula nFe2O3·mH2O (n=1-3, m=1-4), MnO2·nH2O. Crystal water significantly affects the concentration of ferromanganese ore, making it impossible to obtain qualified iron and manganese concentrates using gravity separation, magnetic separation, and flotation separation processes. Fluidized bed reduction (FDR) has garnered attention as a relatively efficient and effective technology for processing high-crystallization-water ferromanganese resources. However, during FDR, the iron element in high-crystallization-water ferromanganese ore requires a low reaction temperature and a weak reducing atmosphere, while the manganese element requires a high reaction temperature and a strong reducing atmosphere. Therefore, when the high-crystallization water iron-manganese ore is subjected to one-step fluidized reduction, when the reaction conditions meet the requirements of the iron element, the reduction effect of iron is good, but the reduction conditions of the manganese element are insufficient, and the reduction effect is poor; when the reaction conditions meet the requirements of the manganese element, the reduction effect of manganese is good, but the reduction conditions of the iron element are excessive, and it is easy to over-reduction to generate non-magnetic FeO, which cannot be recovered by magnetic separation, and the reduction effect is poor. Summary of the Invention

[0013] In response to the shortcomings of the prior art in the one-step fluidized reduction process for highly crystalline hydroferromanganese ore, the present invention proposes a step-by-step fluidized reduction method and apparatus for iron and manganese in highly crystalline hydroferromanganese ore. The present invention utilizes a step-by-step fluidized reduction process for highly crystalline hydroferromanganese ore. First, the highly crystalline hydroferromanganese ore is fed into a first furnace tube, and a first reducing gas is introduced into the first furnace tube. The iron minerals in the highly crystalline hydroferromanganese ore react with the first reducing gas to reduce Fe2O3 to Fe3O4. The material discharged from the first furnace tube is then cooled and magnetically separated to obtain an iron ore magnetic concentrate. The non-magnetic manganese minerals are then fed into a second furnace tube for reduction. The manganese minerals react with the second reducing gas introduced into the second furnace tube to reduce MnO2 to MnO. After cooling, a MnO reduction product is obtained. The present invention utilizes the difference in reduction reaction conditions of iron and manganese compounds in high-crystallization water ferromanganese ore, and performs a two-step fluidized reduction, wherein the first step reduces the iron mineral and the second step reduces the manganese mineral. This effectively avoids the problems of insufficient manganese reduction conditions or excessive iron reduction conditions in the one-step reduction of the prior art, and achieves a significant reduction effect, thereby realizing the comprehensive recovery of iron and manganese elements and improving resource utilization.

[0014] According to a first embodiment of the present invention, a step-by-step fluidized reduction method for iron and manganese in high-crystallization water ferromanganese ore is provided.

[0015] A step-by-step fluidized reduction method for iron and manganese in high-crystallization water ferromanganese ore, the method comprising the following steps:

[0016] 1) Raw materials are fed into the furnace: high crystallization water iron manganese ore is transported into the first furnace tube.

[0017] 2) Fluidized Reduction of Iron Ore: A first reducing gas is introduced from the bottom of the first furnace tube. The first reducing gas flows upward, fluidizing the highly crystalline hydroferromanganese ore. The first reducing gas reacts with the iron ore in the highly crystalline hydroferromanganese ore, reducing Fe₂O₃ to Fe₃O₄.

[0018] 3) Cooling and Magnetic Separation of the Material Discharged from the First Furnace Tube: After the reduction reaction of the iron ore is complete, the flow rate of the first reducing gas is increased to blow the reacted material out of the first furnace tube. The material discharged from the first furnace tube undergoes cooling and magnetic separation to obtain the iron ore magnetic concentrate. The non-magnetic manganese ore after the magnetic separation process is transferred to the tailings.

[0019] 4) Fluidized reduction of manganese ore: The dried tailings are transferred to a second furnace tube. Simultaneously, a second reducing gas is introduced from the bottom of the second furnace tube. The second reducing gas flows upward, fluidizing the tailings. The second reducing gas reacts with the manganese ore in the tailings, reducing MnO2 to MnO.

[0020] 5) Cooling of the material discharged from the second furnace tube: After the reduction reaction of the manganese ore is completed, the flow rate of the second reducing gas is increased to blow the reacted material out of the second furnace tube and cool it to obtain a MnO reduction product.

[0021] In the present invention, the method further comprises:

[0022] 6) Recycling of reducing gas: The reaction gas in the first furnace tube in step 2) enters the second furnace tube. While preheating the second furnace tube, the remaining reducing gas continues to participate in the reduction reaction in the second furnace tube. The reaction gas in the second furnace tube in step 4) circulates to the first furnace tube. While heating the first furnace tube, the remaining reducing gas continues to participate in the reduction reaction in the first furnace tube.

[0023] In the present invention, the first reducing gas and the second reducing gas are each independently a mixture of one or more reducing gases and N2. Preferably, the reducing gas is CO or H2, preferably CO.

[0024] More preferably, the content of reducing gas in the first reducing gas is 1-20%, preferably 2-18%, more preferably 3-15%.

[0025] More preferably, the content of reducing gas in the second reducing gas is 3-60%, preferably 5-55%, and more preferably 8-50%.

[0026] In the present invention, the reduction reaction temperature of the iron ore in the first furnace tube is 300-800° C., preferably 350-750° C., more preferably 400-700° C. The reduction reaction time of the iron ore is 0.1-1 h, preferably 0.2-0.8 h, more preferably 0.3-0.7 h.

[0027] In the present invention, the reduction reaction temperature of the manganese ore in the second furnace tube is 600-1000° C., preferably 650-950° C., more preferably 700-900° C. The reduction reaction time of the manganese ore is 0.3-2 h, preferably 0.4-1.8 h, more preferably 0.5-1.5 h.

[0028] In the present invention, step 1) specifically comprises grinding the highly crystalline hydroferromanganese ore, and then feeding the resulting highly crystalline hydroferromanganese ore particles into the first furnace tube through a feed port at the lower portion of the first furnace tube. Preferably, the particle size of the ground highly crystalline hydroferromanganese ore particles is 0.1-1 mm, more preferably 0.2-0.9 mm.

[0029] Preferably, in step 4), the dried tailings are fed into the second furnace tube from a feed port at the lower portion of the second furnace tube.

[0030] In the present invention, during the reduction reaction of the iron ore, the flow rate of the first reducing gas is 0.2-2 m / s, preferably 0.3-1.8 m / s, and more preferably 0.5-1.5 m / s.

[0031] In the present invention, during the reduction reaction of the manganese ore, the flow rate of the second reducing gas is 0.5-1.5 m / s, preferably 0.6-1.4 m / s, and more preferably 0.7-1.3 m / s.

[0032] Preferably, an O and Fe element detection device is provided at the discharge port of the first furnace tube, and the content of the reducing gas in the first furnace tube is adjusted according to the real-time detected O / Fe molar ratio to ensure the reduction of the iron ore.

[0033] Preferably, an O and Mn element detection device is provided at the discharge port of the second furnace tube, and the content of the reducing gas in the second furnace tube is adjusted according to the real-time detected O / Mn molar ratio to ensure the reduction of the manganese ore.

[0034] In the present invention, in step 2), the O / Fe mol ratio at the first furnace tube discharge port is detected in real time and is designated as a(O / Fe). When the interval of the O / Fe mol ratio detected is a(O / Fe)>1.33, the reducing gas content in the first furnace tube is insufficient, and the reducing gas content b=2.0*a(O / Fe)% that needs to be increased is now. When the interval of the O / Fe mol ratio detected is 1<a(O / Fe)≤1.33, the reducing gas content in the first furnace tube meets the requirements, and the reducing gas content remains unchanged. When the interval of the O / Fe mol ratio detected is 0<a(O / Fe)≤1, the reducing gas content in the first furnace tube is excessive, and the reducing gas content b=3.0*[a(O / Fe)+1]% that needs to be reduced is now.

[0035] In the present invention, in step 4), the O / Mn molar ratio at the discharge port of the second furnace tube is detected in real time and is recorded as a(O / Mn). When the interval of the detected O / Mn molar ratio is 1.0<a(O / Mn)≤2.0, it indicates that the reducing gas content in the second furnace tube is insufficient, and the reducing gas content c=3.0*[a(O / Mn)+1]% needs to be increased. When the interval of the detected O / Mn molar ratio is 0.5<a(O / Mn)≤1.0, it indicates that the reducing gas content in the second furnace tube meets the requirements, and the reducing gas content remains unchanged. When the interval of the detected O / Mn molar ratio is 0<a(O / Mn)≤0.5, it indicates that the reducing gas content in the second furnace tube is excessive, and the reducing gas content c=4.0*[a(O / Mn)+2]% needs to be reduced.

[0036] According to a second embodiment of the present invention, a device for fluidized reduction of iron and manganese in high-crystallization water ferromanganese ore is provided.

[0037] A device for the stepwise fluidized reduction of iron and manganese in highly crystalline hydroferromanganese ore, or a device for reducing highly crystalline hydroferromanganese ore using the method described in the first embodiment, comprises a first furnace tube, a second furnace tube, a first water-cooling tank, a magnetic separator, a filter, a dryer, and a second water-cooling tank. The first furnace tube is provided with a first material inlet, a first reducing gas inlet, a first reducing gas outlet, and a first material outlet. The second furnace tube is provided with a second material inlet, a second reducing gas inlet, a second reducing gas outlet, and a second material outlet. The first material inlet and the first material outlet are respectively located at the lower and upper portions of the sidewall of the first furnace tube. The first reducing gas inlet and the first reducing gas outlet are respectively located at the bottom and top portions of the sidewall of the second furnace tube. The second material inlet and the second material outlet are respectively located at the lower and upper portions of the sidewall of the second furnace tube. The second reducing gas inlet and the second reducing gas outlet are respectively located at the bottom and top portions of the second furnace tube. The first material outlet of the first furnace tube is connected to the first water-cooling tank. The material outlet of the first water-cooling tank is connected to the feed inlet of the magnetic separator. The non-magnetic material outlet of the magnetic separator is connected to the filter. The material outlet of the filter is connected to the dryer. The material outlet of the dryer is connected to the second material inlet of the second furnace tube. The second material outlet of the second furnace tube is connected to the second water cooling tank.

[0038] In the present invention, the first gas outlet of the first furnace tube is connected to the second gas inlet of the second furnace tube via a first pipe. The second gas outlet of the second furnace tube is connected to the first gas inlet of the first furnace tube via a second pipe.

[0039] Preferably, the device further comprises an O and Fe element detection device arranged at the first material outlet position of the first furnace tube.

[0040] Preferably, the device further comprises an O and Mn element detection device arranged at the second material outlet position of the second furnace tube.

[0041] To address the problems of insufficient manganese reduction conditions or excessive iron reduction conditions in the one-step fluidized reduction of highly crystalline hydroferromanganese ore in the prior art, the present invention proposes a step-by-step fluidized reduction method for iron and manganese in highly crystalline hydroferromanganese ore. The method utilizes a step-by-step fluidized reduction process for highly crystalline hydroferromanganese ore. First, the highly crystalline hydroferromanganese ore is fed into a first furnace tube, and a first reducing gas is introduced into the first furnace tube. The iron minerals in the highly crystalline hydroferromanganese ore react with the first reducing gas to reduce Fe2O3 to Fe3O4. The material discharged from the first furnace tube is then cooled and magnetically separated to obtain an iron ore magnetic concentrate. The non-magnetic manganese minerals are then fed into a second furnace tube for reduction. The manganese minerals react with the second reducing gas introduced into the second furnace tube to reduce MnO2 to MnO. After cooling, a MnO reduction product is obtained. The present invention utilizes the difference in reduction reaction conditions of iron and manganese compounds in high-crystallization water ferromanganese ore, and performs a two-step fluidized reduction, wherein the first step reduces the iron mineral and the second step reduces the manganese mineral. This effectively avoids the problems of insufficient manganese reduction conditions or excessive iron reduction conditions in the one-step reduction of the prior art, and achieves a significant reduction effect, thereby realizing the comprehensive recovery of iron and manganese elements and improving resource utilization.

[0042] As preferred version, the reducing gas in the first furnace tube and the second furnace tube (comprising the first reducing gas and the second reducing gas) can adopt the mode of recycling among the present invention, wherein, the reaction gas after the reduction of the iron ore in the first furnace tube (from the bottom of the second furnace tube) enters in the second furnace tube, this part reaction gas not only can preheat the second furnace tube, and remaining reducing gas can continue to participate in the reduction reaction of manganese ore in the reaction gas; And the reaction gas after the reduction of the manganese ore in the second furnace tube then (from the bottom of the first furnace tube) enters the first furnace tube, this part reaction gas can provide heat source for the first furnace tube, remaining reducing gas can also continue to utilize in the first furnace tube, participate in the reduction reaction of iron ore, because the reduction of iron ore requires a weaker reducing atmosphere (with respect to the reduction of manganese ore), therefore, when remaining reducing gas is more in this part reaction gas, even the first furnace tube does not need to additionally add reducing gas. The present invention recycles the reducing gas in the first furnace tube and the second furnace tube, and when realizing the comprehensive recovery of iron and manganese elements, reduces investment cost, improves resource utilization.

[0043] In the present invention, the first reducing gas is a mixed gas of one or more reducing gases and N2 (or an inert gas, such as Ar, He, etc.). The reducing gas is CO or H2, preferably CO. In the first reducing gas, the content of reducing gas is 1-20%, preferably 2-18%, more preferably 3-15%, and the remaining gas is N2 or an inert gas. Similarly, the second reducing gas is also a mixed gas of one or more reducing gases and N2 (or an inert gas, such as Ar, He, etc.). The reducing gas is CO or H2, preferably CO. It should be noted that the gas components of the first reducing gas and the second reducing gas can be the same or different, but due to the differences in the reduction reaction conditions of iron minerals and manganese minerals, that is, the reduction of iron minerals requires a low reaction temperature and a weak reducing atmosphere, while the reduction of manganese minerals requires a high reaction temperature and a strong reducing atmosphere, therefore, the content of reducing gas in the second reducing gas is different from the content of reducing gas in the first reducing gas, and is greater than the content of reducing gas in the first reducing gas. Based on this, in the second reducing gas, the content of reducing gas is 3-60%, preferably 5-55%, more preferably 8-50%, and the remaining gas is N2 or inert gas.

[0044] As previously mentioned, the reduction reaction temperatures of the iron ore compound and the manganese ore compound are different. If both are reduced under the same temperature conditions, when the reduction temperature conditions of the manganese ore compound are met, the iron ore compound will be over-reduced to non-magnetic FeO and Fe, and the required Fe3O4 cannot be generated, and magnetic separation recovery cannot be performed, resulting in a poor reduction effect. When the reduction temperature conditions of the iron ore compound are met, the temperature required for the reduction of the manganese ore compound cannot be reached, the reduction conditions are insufficient, and the reduction effect is also poor. Based on this, the present invention sets the reduction temperature of the iron ore compound in the first furnace tube to 300-800°C, preferably 350-750°C, and more preferably 400-700°C; the reaction time of the iron ore compound is 0.1-1h, preferably 0.2-0.8h, and more preferably 0.3-0.7h. The iron ore compound in the high crystallization water iron manganese ore undergoes a reduction reaction under the conditions of a set temperature (300-800 ℃, for example, 500 ℃) and a time (0.1-1h, for example, 0.5h). At this temperature and in a weak reducing atmosphere, Fe2O3 is reduced to Fe3O4, but the conditions for manganese ore reduction are not reached. The material discharged from the first furnace tube after the first step reduction treatment is subjected to magnetic separation, filtration, and drying, and the Fe3O4 obtained by the reduction is magnetically recovered, while the non-magnetic manganese ore compound is sent to the second furnace tube for the second step reduction treatment. Accordingly, the present invention sets the reduction temperature of the manganese ore compound in the second furnace tube to 600-1000 ℃, preferably 650-950 ℃, more preferably 700-900 ℃. The reaction time is 0.3-2h, preferably 0.4-1.8h, more preferably 0.5-1.5h. The non-magnetic manganese ore compound undergoes a reduction reaction under set temperature (600-1000° C., such as 800° C.) and time (0.3-2 hours, such as 1.1 hours), and MnO2 is reduced to MnO at this temperature and in a strong reducing atmosphere.

[0045] To ensure that high crystallization hydroferromanganese ore can be fluidized smoothly after entering the first furnace tube, thus before entering the furnace, high crystallization hydroferromanganese ore needs to be ground so that its particle size can meet the particle size requirement of fluidized reduction. In the present invention, the particle size of the high crystallization hydroferromanganese ore particles obtained after grinding is 0.1-1mm, preferably 0.2-0.9mm. Considering that the first furnace tube is high crystallization hydroferromanganese ore particles, namely including iron minerals and manganese minerals, the second furnace tube is mainly manganese minerals, based on the different specific gravity of the two iron minerals and manganese minerals, the present invention controls the flow velocity of the first reducing gas entering the first furnace tube and the flow velocity of the second reducing gas entering the second furnace tube respectively, to ensure that high crystallization hydroferromanganese ore particles can be fluidized smoothly in the first furnace tube, and manganese mineral particles can be fluidized smoothly in the second furnace tube. During the reduction of iron ore in the first furnace tube, the flow rate of the first reducing gas is 0.2-2 m / s, preferably 0.3-1.8 m / s, and more preferably 0.5-1.5 m / s. During the reduction of manganese ore in the second furnace tube, the flow rate of the second reducing gas is 0.5-1.5 m / s, preferably 0.6-1.4 m / s, and more preferably 0.7-1.3 m / s. It should be noted that after the reduction reaction of the iron ore or manganese ore is completed, it is necessary to increase the flow rate of the first reducing gas or the flow rate of the second reducing gas to blow the reacted materials out of the first furnace tube or the second furnace tube.

[0046] As a preferred embodiment, the present invention further provides an O and Fe element detection device at the discharge port of the first furnace tube for real-time detection of the O / Fe molar ratio in the material at the discharge port of the first furnace tube. The device adjusts the content of reducing gas (e.g., CO or H2) in the first furnace tube based on the real-time detected O / Fe molar ratio to ensure proper reduction of the iron ore. Accordingly, the present invention further provides an O and Mn element detection device at the discharge port of the second furnace tube for real-time detection of the O / Mn molar ratio in the material at the discharge port of the second furnace tube. The device adjusts the content of reducing gas in the second furnace tube based on the real-time detected O / Mn molar ratio to ensure proper reduction of the manganese ore. In the present invention, the O and Fe element detection devices detect the molar amount of O and the molar amount of Fe in the material discharged from the discharge port of the first furnace tube. The molar amount of O in the O / Fe molar ratio is calculated by subtracting the molar amount of O in MnO2 from the molar amount of O detected in the entire material. That is, the molar amount of O when calculating the O / Fe molar ratio = the molar amount of O detected in the material - the molar amount of O in MnO2. The molar amount of O in MnO2 = the molar amount of Mn in the material * 2. The molar amount of Mn in the material can be obtained by testing the raw material composition.

[0047] In the reduction process of iron ore, the O / Fe molar ratio at the first furnace tube discharge port is detected by the O and Fe element detection device in real time, denoted as a(O / Fe), when the detected O / Fe molar ratio is in the range of a(O / Fe)>1.33, at this time Fe2O3 is mainly in the system, indicating that the reduction reaction is not complete, the system is insufficient in the content of reducing gas, and the content of reducing gas to be increased b=2.0*a(O / Fe)%. When the detected O / Fe molar ratio is in the range of 1

[0048] The present invention discloses a method for the step-by-step fluidized reduction of iron and manganese in highly crystalline hydroferromanganese ore. Aiming at the shortcoming of the difficulty in synchronously reducing iron and manganese minerals in the fluidized reduction process of highly crystalline hydroferromanganese ore, the present invention proposes a new process for the step-by-step reduction of highly crystalline hydroferromanganese ore based on the differences in the reduction conditions of iron and manganese minerals. First, highly crystalline hydroferromanganese ore of a certain particle size enters the fluidized reduction system from the lower part of the first furnace tube, and a first reducing gas enters the system from the bottom of the first furnace tube at a certain airflow velocity, with the running direction being from bottom to top. The material is controlled to be suspended in the first furnace tube by adjusting the airflow velocity. The first reducing gas reacts with the iron minerals in the highly crystalline hydroferromanganese ore under set temperature and time conditions, and Fe2O3 is reduced to Fe3O4 under a lower reduction reaction temperature and a weak reducing atmosphere, at which point the conditions for the reduction of manganese minerals are not met. An O and Fe element detection device is provided at the discharge port of the first furnace tube, and the content of the reducing gas in the first reducing gas is adjusted according to the detected O / Fe molar ratio in the material at the discharge port position to ensure the proper reduction of the iron minerals. When the reduction reaction of the iron ore is complete, the flow rate of the first reducing gas is increased, and the material is blown into the first water-cooling pool for cooling. Magnetic separation is then performed to obtain the iron ore concentrate, and the non-magnetic manganese compounds enter the tailings. Next, the tailings, or manganese compounds, are dried and then enter the fluidized reduction system from the lower portion of the second furnace tube. By adjusting the flow rate of the second reducing gas introduced into the second furnace tube, the material is suspended within the second furnace tube. The second reducing gas reacts with the manganese ore in the high-crystallization-water iron-manganese ore under predetermined temperature and time conditions, reducing MnO2 to MnO at the high reduction reaction temperature and in a strong reducing atmosphere. Elemental O and Mn detection devices are installed at the discharge port of the second furnace tube. The reducing gas content in the second reducing gas is adjusted based on the detected O / M molar ratio in the material at the discharge port to ensure proper reduction of the manganese ore. When the reduction reaction of the manganese ore is complete, the flow rate of the second reducing gas is increased, and the material is blown into the second water-cooling pool for cooling. After dehydration, the material enters the hydrometallurgical system. In addition, the high-temperature flue gas and reducing gas of the two fluidized reduction systems (i.e., including the first furnace tube and the second furnace tube) of the present invention can be recycled. The reaction gas of the first furnace tube enters the second furnace tube, which can be preheated, and the residual reducing gas can be continued to be used in the second furnace tube; the reaction gas of the second furnace tube returns to the first furnace tube, which can provide a heat source for the first furnace tube, and the residual reducing gas continues to be used in the first furnace tube, and even the first furnace tube does not need to add additional reducing gas. The technical route of the present invention is to utilize the difference in the reduction reaction conditions of the iron and manganese compounds of high-crystallization water ferromanganese ore, through two-step fluidized reduction, the first step is to reduce the iron compound, and the second step is to reduce the manganese compound, and the high-temperature reducing gas is recycled, which can realize the comprehensive recovery of iron and manganese elements, improve resource utilization, and comply with national industrial policies. The promotion of the present invention has good economic and environmental benefits, and is expected to open up a more stable and efficient way for the development and utilization of high-crystallization water ferromanganese ore.

[0049] Based on the above-mentioned step-by-step fluidized reduction method for iron and manganese in highly crystalline hydroferromanganese ore, the present invention also proposes a step-by-step fluidized reduction device for iron and manganese in highly crystalline hydroferromanganese ore. Along the material flow path, the device includes a first furnace tube, a first water-cooling tank, a magnetic separator, a filter, a dryer, a second furnace tube, and a second water-cooling tank connected in sequence. The first furnace tube provides a place for the fluidized reduction of iron minerals in highly crystalline hydroferromanganese ore, and thus the first furnace tube is provided with a first material inlet, a first reducing gas inlet, a first reducing gas outlet, and a first material outlet. To better achieve the fluidization of the material in the first furnace tube, the first material inlet and the first material outlet are respectively arranged at the lower and upper parts of the side wall of the first furnace tube, and the first reducing gas inlet and the first reducing gas outlet are respectively arranged at the bottom and top of the first furnace tube. Correspondingly, the second furnace tube provides a place for the fluidized reduction of manganese minerals in highly crystalline hydroferromanganese ore, and thus the second furnace tube is provided with a second material inlet, a second reducing gas inlet, a second reducing gas outlet, and a second material outlet. To better fluidize the material within the second furnace tube, the second material inlet and second material outlet are located at the lower and upper sides of the second furnace tube, respectively. The second reducing gas inlet and second reducing gas outlet are located at the bottom and top of the second furnace tube, respectively. The first reducing gas enters the first furnace tube from the bottom and moves upward. Highly crystallized hydroferromanganese ore enters the first furnace tube from the bottom. Under the influence of the first reducing gas flow, it flows from the lower part of the furnace tube to the upper part, becoming fluidized within the furnace tube. The iron ore in the highly crystallized hydroferromanganese ore undergoes a reduction reaction with the first reducing gas, reducing Fe₂O₃ to Fe₃O₄, completing the reduction of the iron ore. After the reduction reaction is complete, the reacted material is blown out of the first furnace tube and cooled in a first water-cooling tank. It is then separated by a magnetic separator to obtain an iron ore concentrate. The non-magnetic manganese ore is filtered by a filter and dried in a dryer before entering the second furnace tube. The second reducing gas enters the second furnace tube from the bottom and flows upward. Manganese ore enters the second furnace tube from the bottom. Under the influence of the second reducing gas flow, the manganese ore flows from the bottom of the furnace tube to the top of the furnace tube. It becomes fluidized within the furnace tube and reacts with the second reducing gas, reducing MnO2 to MnO, completing the reduction of the manganese ore. After the reduction reaction of the manganese ore is complete, the reacted material is blown out of the second furnace tube and cooled in a second water-cooling tank, where it is cooled to obtain a MnO reduction product.

[0050] Corresponding to the method, in order to realize the recycling of reducing gas in the first furnace tube and the second furnace tube, the device of the present invention connects the first gas outlet of the first furnace tube to the second gas inlet of the second furnace tube via a first pipe, and the second gas outlet of the second furnace tube is connected to the first gas inlet of the first furnace tube via a second pipe.

[0051] The apparatus of the present invention further includes an O and Fe element detection device at the first material outlet of the first furnace tube. Based on the O / Fe molar ratio of the material at the first material outlet of the first furnace tube detected in real time by the O and Fe element detection device, the reducing gas content in the first reducing gas is adjusted in real time to ensure proper reduction of the iron ore. Correspondingly, the apparatus of the present invention further includes an O and Mn element detection device at the second material outlet of the second furnace tube. Based on the O / Mn molar ratio of the material at the second material outlet of the second furnace tube detected in real time by the O and Mn element detection device, the reducing gas content in the second reducing gas is adjusted in real time to ensure proper reduction of the manganese ore.

[0052] In the present invention, multiple first material inlets and second material inlets can be set, and the multiple first material inlets are evenly distributed at the lower part of the side wall of the first furnace tube, and the multiple second material inlets are evenly distributed at the lower part of the side wall of the second furnace tube. Feed pipes can also be set on the first material inlet and the second material inlet to facilitate the transportation of materials.

[0053] In this application, the feed port of the first furnace tube and the first material inlet are synonymous, both indicating the location where material enters the first furnace tube. Accordingly, the discharge port of the first furnace tube and the first material outlet, the feed port of the second furnace tube and the second material inlet, and the discharge port of the second furnace tube and the second material outlet are synonymous.

[0054] Compared with the prior art, the present invention has the following beneficial technical effects:

[0055] 1. The present invention utilizes the difference in reduction reaction conditions of iron and manganese compounds in high-crystallization water ferromanganese ore, and performs a two-step fluidized reduction, wherein the first step reduces iron minerals and the second step reduces manganese minerals. This effectively avoids the problems of insufficient manganese reduction conditions or excessive iron reduction conditions in the one-step reduction of the prior art, and achieves a significant reduction effect, thereby achieving comprehensive recovery of iron and manganese elements and improving resource utilization.

[0056] 2, in the present invention, the reaction gas after the reduction of iron mineral in the first furnace tube enters in the second furnace tube, this part reaction gas not only can preheat the second furnace tube, and remaining reducing gas can continue to participate in the reduction reaction of manganese ore in the second furnace tube in the reaction gas; And the reaction gas after the reduction of manganese ore in the second furnace tube then enters the first furnace tube, this part reaction gas can be that the first furnace tube provides heat source, remaining reducing gas can also continue to utilize in the first furnace tube, participate in the reduction reaction of iron mineral, because the reduction of iron mineral requires a weaker reducing atmosphere (with respect to the reduction of manganese ore), therefore, when remaining reducing gas is more in this part reaction gas, even the first furnace tube does not need to additionally add reducing gas.The present invention recycles the reducing gas in the first furnace tube and the second furnace tube, and when realizing the comprehensive recovery of iron and manganese elements, reduces investment cost, improves resource utilization.

[0057] 3. The present invention further provides an O and Fe element detection device at the discharge port of the first furnace tube for real-time detection of the O / Fe molar ratio of the material at the discharge port of the first furnace tube, and adjusts the content of the reducing gas in the first furnace tube according to the real-time detected O / Fe molar ratio to ensure proper reduction of the iron ore. The present invention further provides an O and Mn element detection device at the discharge port of the second furnace tube for real-time detection of the O / Mn molar ratio of the material at the discharge port of the second furnace tube, and adjusts the content of the reducing gas in the second furnace tube according to the real-time detected O / Mn molar ratio to ensure proper reduction of the manganese ore.

[0058] The promotion of the present invention has good economic and environmental benefits, and is expected to open up a more stable and efficient way for the development and utilization of high-crystallization water iron manganese ore. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 This is a schematic diagram of the first structure of a device for stepwise fluidized reduction of iron and manganese in high-crystallization water ferromanganese ore according to the present invention;

[0060] Figure 2 This is a second structural schematic diagram of a step-by-step fluidized reduction device for iron and manganese in high-crystallization water ferromanganese ore according to the present invention.

[0061] Reference numerals:

[0062] 1: First furnace tube; 101: First material inlet; 102: First reducing gas inlet; 103: First reducing gas outlet; 104: First material outlet; 2: Second furnace tube; 201: Second material inlet; 202: Second reducing gas inlet; 203: Second reducing gas outlet; 204: Second material outlet; 3: First water-cooling tank; 4: Magnetic separator; 5: Filter; 6: Dryer; 7: Second water-cooling tank; 8: O and Fe element detection device; 9: O and Mn element detection device; L1: First pipeline; L2: Second pipeline. DETAILED DESCRIPTION

[0063] The technical solutions of the present invention are illustrated below with examples, and the scope of protection requested by the present invention includes but is not limited to the following embodiments.

[0064] According to a second embodiment of the present invention, a device for fluidized reduction of iron and manganese in high-crystallization water ferromanganese ore is provided.

[0065] A device for the stepwise fluidized reduction of iron and manganese in highly crystalline hydroferromanganese ore, or a device for reducing highly crystalline hydroferromanganese ore using the method described in the first embodiment, comprises a first furnace tube 1, a second furnace tube 2, a first water-cooling pool 3, a magnetic separator 4, a filter 5, a dryer 6, and a second water-cooling pool 7. The first furnace tube 1 is provided with a first material inlet 101, a first reducing gas inlet 102, a first reducing gas outlet 103, and a first material outlet 104. The second furnace tube 2 is provided with a second material inlet 201, a second reducing gas inlet 202, a second reducing gas outlet 203, and a second material outlet 204. The first material inlet 101 and the first material outlet 104 are respectively disposed at the lower and upper portions of the sidewall of the first furnace tube 1. The first reducing gas inlet 102 and the first reducing gas outlet 103 are respectively disposed at the bottom and top portions of the first furnace tube 1. The second material inlet 201 and the second material outlet 204 are respectively disposed at the lower and upper portions of the sidewall of the second furnace tube 2. The second reducing gas inlet 202 and the second reducing gas outlet 203 are respectively arranged at the bottom and top of the second furnace tube 2. The first material outlet 104 of the first furnace tube 1 is connected to the first water cooling pool 3. The material outlet of the first water cooling pool 3 is connected to the feed port of the magnetic separator 4. The non-magnetic material outlet of the magnetic separator 4 is connected to the filter 5. The material outlet of the filter 5 is connected to the dryer 6. The material outlet of the dryer 6 is connected to the second material inlet 201 of the second furnace tube 2. The second material outlet 204 of the second furnace tube 2 is connected to the second water cooling pool 7.

[0066] In the present invention, the first gas outlet 103 of the first furnace tube 1 is connected to the second gas inlet 202 of the second furnace tube 2 via the first pipe L1. The second gas outlet 203 of the second furnace tube 2 is connected to the first gas inlet 102 of the first furnace tube 1 via the second pipe L2.

[0067] Preferably, the device further comprises an O and Fe element detection device 8 arranged at the first material outlet 104 of the first furnace tube 1 .

[0068] Preferably, the device further comprises an O and Mn element detection device 9 arranged at the second material outlet 204 of the second furnace tube 2 .

[0069] Example 1

[0070] like Figure 1As shown, a step-by-step fluidized reduction device for iron and manganese in highly crystalline hydroferromanganese ore comprises a first furnace tube 1, a second furnace tube 2, a first water-cooling pool 3, a magnetic separator 4, a filter 5, a dryer 6, and a second water-cooling pool 7. The first furnace tube 1 is provided with a first material inlet 101, a first reducing gas inlet 102, a first reducing gas outlet 103, and a first material outlet 104. The second furnace tube 2 is provided with a second material inlet 201, a second reducing gas inlet 202, a second reducing gas outlet 203, and a second material outlet 204. The first material inlet 101 and the first material outlet 104 are respectively disposed at the lower and upper portions of the sidewall of the first furnace tube 1. The first reducing gas inlet 102 and the first reducing gas outlet 103 are respectively disposed at the bottom and top portions of the first furnace tube 1. The second material inlet 201 and the second material outlet 204 are respectively disposed at the lower and upper portions of the sidewall of the second furnace tube 2. The second reducing gas inlet 202 and the second reducing gas outlet 203 are respectively arranged at the bottom and top of the second furnace tube 2. The first material outlet 104 of the first furnace tube 1 is connected to the first water cooling pool 3. The material outlet of the first water cooling pool 3 is connected to the feed port of the magnetic separator 4. The non-magnetic material outlet of the magnetic separator 4 is connected to the filter 5. The material outlet of the filter 5 is connected to the dryer 6. The material outlet of the dryer 6 is connected to the second material inlet 201 of the second furnace tube 2. The second material outlet 204 of the second furnace tube 2 is connected to the second water cooling pool 7.

[0071] Example 2

[0072] like Figure 2 As shown, Example 1 is repeated except that the first gas outlet 103 of the first furnace tube 1 is connected to the second gas inlet 202 of the second furnace tube 2 via a first pipe L1. The second gas outlet 203 of the second furnace tube 2 is connected to the first gas inlet 102 of the first furnace tube 1 via a second pipe L2.

[0073] Example 3

[0074] Example 2 is repeated, except that the device further includes an O and Fe element detection device 8 disposed at the first material outlet 104 of the first furnace tube 1. The device further includes an O and Mn element detection device 9 disposed at the second material outlet 204 of the second furnace tube 2.

[0075] Example 4

[0076] A step-by-step fluidized reduction method for iron and manganese in highly crystalline hydrometallurgical ferromanganese ore, using the apparatus described in Example 1, comprises the following steps:

[0077] 1) Raw materials are fed into the furnace: the high-crystallization water iron manganese ore is transported into the first furnace tube 1.

[0078] 2) Fluidized Reduction of Iron Ore: A first reducing gas is introduced from the bottom of the first furnace tube 1. The first reducing gas flows upward, fluidizing the highly crystalline hydrometallurgical ferromanganese ore. The first reducing gas reacts with the iron ore in the highly crystalline hydrometallurgical ferromanganese ore, reducing Fe₂O₃ to Fe₃O₄.

[0079] 3) Cooling and Magnetic Separation of the Material Discharged from the First Furnace Tube: After the reduction reaction of the iron ore is complete, the flow rate of the first reducing gas is increased to blow the reacted material out of the first furnace tube 1. The material discharged from the first furnace tube 1 undergoes cooling and magnetic separation to obtain the iron ore magnetic separation concentrate. The non-magnetic manganese ore after the magnetic separation process is transferred to the tailings.

[0080] 4) Fluidized Reduction of Manganese Ore: The dried tailings are transferred to the second furnace tube 2. Simultaneously, a second reducing gas is introduced from the bottom of the second furnace tube 2. The second reducing gas flows upward, fluidizing the tailings. The second reducing gas reacts with the manganese ore in the tailings, reducing MnO2 to MnO.

[0081] 5) Cooling of the material discharged from the second furnace tube: After the reduction reaction of the manganese ore is completed, the flow rate of the second reducing gas is increased to blow the reacted material out of the second furnace tube 2 and cool it to obtain a MnO reduction product.

[0082] Example 5

[0083] A step-by-step fluidized reduction method for iron and manganese in highly crystalline hydrometallurgical ferromanganese ore, using the apparatus described in Example 2, comprises the following steps:

[0084] 1) Raw materials are fed into the furnace: the high-crystallization water iron manganese ore is transported into the first furnace tube 1.

[0085] 2) Fluidized Reduction of Iron Ore: A first reducing gas is introduced from the bottom of the first furnace tube 1. The first reducing gas flows upward, fluidizing the highly crystalline hydrometallurgical ferromanganese ore. The first reducing gas reacts with the iron ore in the highly crystalline hydrometallurgical ferromanganese ore, reducing Fe₂O₃ to Fe₃O₄.

[0086] 3) Cooling and Magnetic Separation of the Material Discharged from the First Furnace Tube: After the reduction reaction of the iron ore is complete, the flow rate of the first reducing gas is increased to blow the reacted material out of the first furnace tube 1. The material discharged from the first furnace tube 1 undergoes cooling and magnetic separation to obtain the iron ore magnetic separation concentrate. The non-magnetic manganese ore after the magnetic separation process is transferred to the tailings.

[0087] 4) Fluidized reduction of manganese minerals: After drying, the tailings are transported into the second furnace tube 2, and a second reducing gas is introduced from the bottom of the second furnace tube 2, which moves upward. The tailings are in a fluidized state under the action of the gas flow of the second reducing gas. The second reducing gas reacts with the manganese minerals in the tailings to reduce Mn02to MnO.

[0088] 5) Cooling of the second furnace tube discharge material: After the reduction reaction of the manganese minerals is completed, the flow rate of the second reducing gas is increased to blow the reacted material out of the second furnace tube 2 and cool it, and the MnO reduction product is obtained after cooling.

[0089] 6) Recycling of the reducing gas: The reaction gas in the first furnace tube 1 in step 2) enters the second furnace tube 2, and the residual reducing gas continues to participate in the reduction reaction in the second furnace tube 2 while preheating the second furnace tube 2. The reaction gas in the second furnace tube 2 in step 4) circulates to the first furnace tube 1, and the residual reducing gas continues to participate in the reduction reaction in the first furnace tube 1 while heating the first furnace tube 1.

[0090] Example 6

[0091] A method for stepwise fluidized reduction of iron and manganese in high-crystalline water iron-manganese ore, using the device described in Example 3, includes the following steps:

[0092] 1) Raw material into the furnace: The high-crystalline water iron-manganese ore is ground, and then the ground high-crystalline water iron-manganese ore particles are fed into the first furnace tube 1 from the first material inlet 101 at the lower part of the first furnace tube 1. The particle size of the ground high-crystalline water iron-manganese ore is 0.5 mm.

[0093] 2) Fluidized reduction of iron minerals: A first reducing gas is introduced from the bottom of the first furnace tube 1, which moves upward. The high-crystalline water iron-manganese ore is in a fluidized state under the action of the gas flow of the first reducing gas. The first reducing gas reacts with the iron minerals in the high-crystalline water iron-manganese ore to reduce Fe203to Fe304.

[0094] The first reducing gas is a mixture of CO and N2. The content of CO in the first reducing gas is 10%. In the first furnace tube 1, the reduction reaction temperature of the iron minerals is 550°C. The reduction reaction time of the iron minerals is 0.5 h. During the reduction reaction of the iron minerals, the flow rate of the first reducing gas is 1.2 m / s.

[0095] 3) Cooling and magnetic separation of the material discharged from the first furnace tube: after the reduction reaction of the iron ore is completed, the flow rate of the first reducing gas is increased, and the reacted material is blown out of the first furnace tube 1. The material discharged from the first furnace tube 1 is sequentially subjected to the cooling and magnetic separation processes, and the iron ore magnetic separation concentrate is obtained. The non-magnetic manganese ore after the magnetic separation process enters the tailings.

[0096] 4) Fluidized reduction of the manganese ore: the tailings after drying are fed into the second furnace tube 2 through the second material inlet 201 at the lower part of the second furnace tube 2, and the second reducing gas is introduced from the bottom of the second furnace tube 2. The second reducing gas moves upward, and the tailings are in a fluidized state under the action of the gas flow of the second reducing gas. The second reducing gas reacts with the manganese ore in the tailings to reduce MnO2 to MnO.

[0097] The second reducing gas is a mixture of CO and N2. The content of CO in the second reducing gas is 31%. In the second furnace tube 2, the reduction reaction temperature of the manganese ore is 800°C. The reduction reaction time of the manganese ore is 1.1 h. During the reduction reaction of the manganese ore, the flow rate of the second reducing gas is 1.0 m / s.

[0098] 5) Cooling of the material discharged from the second furnace tube: after the reduction reaction of the manganese ore is completed, the flow rate of the second reducing gas is increased, and the reacted material is blown out of the second furnace tube 2 and cooled, and the MnO reduction product is obtained after cooling.

[0099] 6) Recycling of the reducing gas: the reaction gas in the first furnace tube 1 in step 2) enters the second furnace tube 2, and the residual reducing gas continues to participate in the reduction reaction in the second furnace tube 2 while preheating the second furnace tube 2. The reaction gas in the second furnace tube 2 in step 4) circulates to the first furnace tube 1, and the residual reducing gas continues to participate in the reduction reaction in the first furnace tube 1 while heating the first furnace tube 1.

[0100] In this embodiment, the iron ore magnetic separation concentrate reduction product is obtained in step 3), and the MnO reduction product is obtained in step 5). In the iron ore magnetic separation concentrate reduction product, the ratio of the magnetic iron content to the total iron content mFe / TFe is 95.3%; in the MnO reduction product, the ratio of the MnO content to the total manganese content MnO / TMn is 96.2%. It can be seen that the purity of the two reduction products is very high. Therefore, based on the difference in the reduction conditions of iron and manganese ores, the application adopts a new process of stepwise fluidized reduction for high-crystallization water iron-manganese ore, effectively avoids the problems of insufficient reduction conditions of manganese elements or excessive reduction conditions of iron elements in the existing one-step reduction technology, and significantly improves the reduction effect, thereby realizing the comprehensive recovery of iron and manganese elements and improving the resource utilization rate.

[0101] Example 7

[0102] Example 6 was repeated, except that the first reducing gas was a mixture of H2 and N2. The H2 content in the first reducing gas was 14%. The second reducing gas was also a mixture of H2 and N2. The H2 content in the second reducing gas was 39%.

[0103] Example 8

[0104] Example 6 was repeated except that the reduction reaction temperature of the iron ore was 600° C. and the reduction reaction time of the iron ore was 0.4 h in the first furnace tube 1. The reduction reaction temperature of the manganese ore was 890° C. and the reduction reaction time of the manganese ore was 0.9 h in the second furnace tube 2.

[0105] Example 9

[0106] Example 6 was repeated, except that in step 1), the particle size of the high-crystallization water iron manganese ore particles obtained after grinding was 0.7 mm. Accordingly, during the reduction reaction of the iron ore, the flow rate of the first reducing gas was 1.4 m / s. During the reduction reaction of the manganese ore, the flow rate of the second reducing gas was 1.2 m / s.

[0107] Example 10

[0108] Example 6 was repeated, except that an O and Fe element detection device 8 was set at the first material outlet 104 of the first furnace tube 1, and the content of the reducing gas in the first furnace tube 1 was adjusted according to the real-time detected O / Fe molar ratio to ensure the reduction of iron ore.

[0109] An O and Mn element detection device 9 is provided at the second material outlet 204 of the second furnace tube 2 to adjust the content of the reducing gas in the second furnace tube 2 according to the real-time detected O / Mn molar ratio to ensure the reduction of manganese ore.

[0110] Example 11

[0111] Example 10 was repeated, except that in step 2), the O / Fe molar ratio at the discharge port of the first furnace tube 1 was detected in real time, denoted as a(O / Fe). When the detected O / Fe molar ratio was a(O / Fe)=1.45, it was obvious that a(O / Fe)>1.33, indicating that the CO content of the reducing gas in the first furnace tube 1 was insufficient. In this case, the CO content needed to be increased by b=2.0*a(O / Fe)%=2.9%.

[0112] In step 4), the O / Mn molar ratio at the discharge port of the second furnace tube 2 is detected in real time and recorded as a(O / Mn). When the detected O / Mn molar ratio a(O / Mn) = 1.8, it is obvious that 1.0 < a(O / Mn) ≤ 2.0, indicating that the CO content of the reducing gas in the second furnace tube 2 is insufficient. In this case, the CO content to be increased is c = 3.0*[a(O / Mn) + 1]% = 8.4%.

[0113] Example 12

[0114] Example 10 was repeated, except that in step 2), the O / Fe molar ratio at the discharge port of the first furnace tube 1 was detected in real time, denoted as a(O / Fe). When the detected O / Fe molar ratio was a(O / Fe)=0.7, it is clear that 0<a(O / Fe)≤1, indicating that the CO content of the reducing gas in the first furnace tube 1 was excessive. In this case, the CO content to be reduced was b=3.0*[a(O / Fe)+1]%=5.1%.

[0115] In step 4), the O / Mn molar ratio at the discharge port of the second furnace tube 2 is detected in real time and recorded as a(O / Mn). When the detected O / Mn molar ratio a(O / Mn) = 0.3, it is obvious that 0 < a(O / Mn) ≤ 0.5, indicating that the CO content of the reducing gas in the second furnace tube 2 is excessive. At this time, the CO content to be reduced is c = 4.0*[a(O / Mn) + 2]% = 9.2%.

[0116] Example 13

[0117] Example 10 was repeated, except that in step 2), the O / Fe molar ratio at the discharge port of the first furnace tube 1 was detected in real time, denoted as a(O / Fe). When the detected O / Fe molar ratio was a(O / Fe) = 1.23, it was apparent that 1 < a(O / Fe) ≤ 1.33, indicating that the CO content of the reducing gas in the first furnace tube 1 met the requirements, and the CO content remained unchanged.

[0118] In step 4), the O / Mn molar ratio at the discharge port of the second furnace tube 2 is detected in real time, denoted as a(O / Mn). When the detected O / Mn molar ratio a(O / Mn) = 0.8, it is obvious that 0.5 < a(O / Mn) ≤ 1.0, indicating that the CO content of the reducing gas in the second furnace tube 2 meets the requirements, and the CO content remains unchanged.

Claims

1. A step-by-step fluidized reduction method for iron and manganese in high-crystallization water ferromanganese ore, the method comprising the following steps: 1) Raw materials are fed into the furnace: high crystallization water iron manganese ore is transported into the first furnace tube (1); 2) Fluidized reduction of iron ore: a first reducing gas is introduced from the bottom of the first furnace tube (1), the first reducing gas moves from bottom to top, and the high-crystallization hydrometallurgical ferromanganese ore is fluidized under the action of the airflow of the first reducing gas; the first reducing gas reacts with the iron ore in the high-crystallization hydrometallurgical ferromanganese ore to reduce Fe2O3 to Fe3O4; 3) Cooling and magnetic separation of the material discharged from the first furnace tube: After the reduction reaction of the iron ore is completed, the flow rate of the first reducing gas is increased to blow the reacted material out of the first furnace tube (1); the material discharged from the first furnace tube (1) is subjected to cooling and magnetic separation processes in sequence to obtain iron ore magnetic separation concentrate; and the non-magnetic manganese ore after the magnetic separation process enters the tailings; 4) Fluidized reduction of manganese ore: the tailings are dried and transported to the second furnace tube (2), and a second reducing gas is introduced from the bottom of the second furnace tube (2). The second reducing gas moves from bottom to top, and the tailings are fluidized under the action of the second reducing gas flow; the second reducing gas reacts with the manganese ore in the tailings to reduce MnO2 to MnO; 5) Cooling of the material discharged from the second furnace tube: After the reduction reaction of the manganese ore is completed, the flow rate of the second reducing gas is increased, and the reacted material is blown out of the second furnace tube (2) and cooled to obtain a MnO reduction product.

2. The method according to claim 1, wherein: The method further includes: 6) Recycling of reducing gas: in step 2), the reaction gas in the first furnace tube (1) enters the second furnace tube (2), and while preheating the second furnace tube (2), the remaining reducing gas continues to participate in the reduction reaction in the second furnace tube (2); in step 4), the reaction gas in the second furnace tube (2) circulates to the first furnace tube (1), and while heating the first furnace tube (1), the remaining reducing gas continues to participate in the reduction reaction in the first furnace tube (1).

3. The method according to claim 1 or 2, characterized in that: The first reducing gas and the second reducing gas are each independently a mixed gas of one or more reducing gases and N2; preferably, the reducing gas is CO or H2, preferably CO; More preferably, the content of reducing gas in the first reducing gas is 1-20%, preferably 2-18%, more preferably 3-15%; and / or The content of reducing gas in the second reducing gas is 3-60%, preferably 5-55%, more preferably 8-50%.

4. The method according to any one of claims 1 to 3, characterized in that: In the first furnace tube (1), the reduction reaction temperature of the iron ore is 300-800°C, preferably 350-750°C, more preferably 400-700°C; the reduction reaction time of the iron ore is 0.1-1h, preferably 0.2-0.8h, more preferably 0.3-0.7h; and / or In the second furnace tube (2), the reduction reaction temperature of the manganese ore is 600-1000°C, preferably 650-950°C, more preferably 700-900°C; the reduction reaction time of the manganese ore is 0.3-2h, preferably 0.4-1.8h, more preferably 0.5-1.5h.

5. The method according to any one of claims 1 to 4, characterized in that: Step 1) specifically comprises: grinding the high-crystalline hydroferromanganese ore, and then feeding the high-crystalline hydroferromanganese ore particles obtained after grinding into the first furnace tube (1) from the feed port at the lower part of the first furnace tube (1); preferably, the particle size of the high-crystalline hydroferromanganese ore particles after grinding is 0.1-1 mm, preferably 0.2-0.9 mm; and / or In step 4), the dried tailings are fed into the second furnace tube (2) from the feed port at the lower portion of the second furnace tube (2).

6. The method according to any one of claims 1 to 5, characterized in that: During the reduction reaction of the iron ore, the flow rate of the first reducing gas is 0.2-2 m / s, preferably 0.3-1.8 m / s, more preferably 0.5-1.5 m / s; and / or During the reduction reaction of the manganese ore, the flow rate of the second reducing gas is 0.5-1.5 m / s, preferably 0.6-1.4 m / s, and more preferably 0.7-1.3 m / s.

7. The method according to any one of claims 3 to 6, characterized in that: An O and Fe element detection device is provided at the discharge port of the first furnace tube (1), and the content of the reducing gas in the first furnace tube (1) is adjusted according to the real-time detected O / Fe molar ratio to ensure the reduction of the iron ore; and / or An O and Mn element detection device is provided at the discharge port of the second furnace tube (2), and the content of the reducing gas in the second furnace tube (2) is adjusted according to the real-time detected O / Mn molar ratio to ensure the reduction of the manganese ore.

8. The method according to claim 7, wherein: In step 2), the O / Fe molar ratio at the discharge port of the first furnace tube (1) is detected in real time, which is recorded as a(O / Fe); when the detected O / Fe molar ratio is within a range of a(O / Fe)>1.33, it indicates that the reducing gas content in the first furnace tube (1) is insufficient, and the reducing gas content b=2.0*a(O / Fe)% needs to be increased at this time; when the detected O / Fe molar ratio is within a range of 1<a(O / Fe)≤1.33, it indicates that the reducing gas content in the first furnace tube (1) meets the requirements, and the reducing gas content remains unchanged at this time; when the detected O / Fe molar ratio is within a range of 0<a(O / Fe)≤1, it indicates that the reducing gas content in the first furnace tube (1) is excessive, and the reducing gas content b=3.0*[a(O / Fe)+1]% needs to be reduced at this time; and / or In step 4), the O / Mn molar ratio at the discharge port of the second furnace tube (2) is detected in real time and is recorded as a(O / Mn); when the detected O / Mn molar ratio is within a range of 1.0<a(O / Mn)≤2.0, it indicates that the reducing gas content in the second furnace tube (2) is insufficient, and the reducing gas content c=3.0*[a(O / Mn)+1]% needs to be increased at this time; when the detected O / Mn molar ratio is within a range of 0.5<a(O / Mn)≤1.0, it indicates that the reducing gas content in the second furnace tube (2) meets the requirements, and the reducing gas content remains unchanged at this time; when the detected O / Mn molar ratio is within a range of 0<a(O / Mn)≤0.5, it indicates that the reducing gas content in the second furnace tube (2) is excessive, and the reducing gas content c=4.0*[a(O / Mn)+2]% needs to be reduced at this time.

9. A device for the stepwise fluidized reduction of iron and manganese in highly crystalline hydroferromanganese ore, or a device for reducing highly crystalline hydroferromanganese ore using the method according to any one of claims 1 to 8, characterized in that: The device comprises a first furnace tube (1), a second furnace tube (2), a first water-cooling pool (3), a magnetic separator (4), a filter (5), a dryer (6), and a second water-cooling pool (7); the first furnace tube (1) is provided with a first material inlet (101), a first reducing gas inlet (102), a first reducing gas outlet (103), and a first material outlet (104); the second furnace tube (2) is provided with a second material inlet (201), a second reducing gas inlet (202), a second reducing gas outlet (203), and a second material outlet (204); wherein the first material inlet (101) and the first material outlet (104) are respectively provided at the lower part and the upper part of the side wall of the first furnace tube (1); the first reducing gas inlet (102) and the first reducing gas outlet (103) are respectively provided at the lower part and the upper part of the side wall of the first furnace tube (1); The first furnace tube (1) is provided with a first material inlet (201) and a second material outlet (204) at the bottom and the top of the side wall of the second furnace tube (2), respectively; the second reducing gas inlet (202) and the second reducing gas outlet (203) are provided at the bottom and the top of the second furnace tube (2), respectively; the first material outlet (104) of the first furnace tube (1) is connected to the first water cooling pool (3); the material outlet of the first water cooling pool (3) is connected to the feed port of the magnetic separator (4); the non-magnetic material outlet of the magnetic separator (4) is connected to the filter (5); the material outlet of the filter (5) is connected to the dryer (6); the discharge port of the dryer (6) is connected to the second material inlet (201) of the second furnace tube (2); and the second material outlet (204) of the second furnace tube (2) is connected to the second water cooling pool (7).

10. The device according to claim 9, characterized in that: The first gas outlet (103) of the first furnace tube (1) is connected to the second gas inlet (202) of the second furnace tube (2) via the first pipe (L1); the second gas outlet (203) of the second furnace tube (2) is connected to the first gas inlet (102) of the first furnace tube (1) via the second pipe (L2); Preferably, the device further comprises an O and Fe element detection device (8) arranged at the first material outlet (104) of the first furnace tube (1); and / or The device further comprises an O and Mn element detection device (9) arranged at the second material outlet (204) of the second furnace tube (2).

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