WO2021031526A1 - 强化复杂难选铁矿石解离的微波连续悬浮焙烧方法 - Google Patents

强化复杂难选铁矿石解离的微波连续悬浮焙烧方法 Download PDF

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WO2021031526A1
WO2021031526A1 PCT/CN2020/071950 CN2020071950W WO2021031526A1 WO 2021031526 A1 WO2021031526 A1 WO 2021031526A1 CN 2020071950 W CN2020071950 W CN 2020071950W WO 2021031526 A1 WO2021031526 A1 WO 2021031526A1
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pretreatment
reduction
iron ore
fluidizer
microwave
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PCT/CN2020/071950
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English (en)
French (fr)
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孙永升
周文涛
韩跃新
李艳军
高鹏
袁帅
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东北大学
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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
    • C22B1/10—Roasting processes in fluidised form

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  • the invention belongs to the technical field of mineral processing, and specifically relates to a microwave continuous suspension roasting method for intensifying the dissociation of complex refractory iron ore.
  • China iron ore resources are abundant.
  • China’s identified iron ore reserves were 84.888 billion tons; however, China’s iron ore resources are generally in grade
  • the characteristics of low crystal grain size and complex mineral composition have resulted in the failure of a large amount of iron ore resources to be effectively developed and utilized, which has forced the iron and steel industry to rely on imports; in 2017, China imported 1.075 billion tons of iron ore, an increase of 7.5%. The degree of foreign dependence exceeds 86%.
  • microwave roasting shows great advantages compared with traditional roasting.
  • the roasting rate is 3.97-7.15 times higher than the traditional roasting rate.
  • the unique selective heating advantage of microwave makes the absorbing characteristics of useful minerals and gangue minerals have a big difference, and then generates internal stress on the mineral joint surface to form cracks and cracks , Can significantly improve the degree of dissociation and grindability of mineral monomers, more energy saving and consumption reduction, and the sorting effect is more significant.
  • the purpose of the present invention is to provide a microwave continuous suspension roasting method that strengthens the dissociation of complex and difficult-to-dress iron ore, through the combination of microwave heat storage pretreatment and suspension magnetization roasting, to selectively and quickly heat storage iron ore materials , Continuous suspension roasting, enhance the dissociation degree of iron mineral monomer, and increase the mineral sorting index, realize the efficient comprehensive development and utilization of complex and difficult-to-dress iron ore.
  • the method of the present invention adopts a microwave continuous suspension roasting system, which includes a feeding silo, a pretreatment fluidizer, a microwave cavity, a microwave generating device, a reducing fluidizer, a cooler and a collection tank; the output at the bottom of the feeding silo
  • the feed port is connected with the feed port of the pretreatment fluidizer.
  • the pretreatment fluidizer is sheathed with a microwave cavity and a pretreatment baffle is arranged inside to divide the interior of the pretreatment fluidizer into a pretreatment feed chamber and pretreatment.
  • the top edge of the pretreatment baffle is connected to the top plate of the pretreatment fluidizer, the two sides of the pretreatment baffle are connected to the side walls of the pretreatment fluidizer, and the bottom edge of the pretreatment baffle is connected to the pretreatment fluidizer.
  • the gap between the bottom plates of the treatment fluidizer is used as a pretreatment channel; the bottom of the pretreatment feed chamber and the pretreatment discharge chamber are respectively provided with a first air inlet and a second air inlet, and the top of the pretreatment feed chamber
  • An air outlet is provided to communicate with the inlet of the gas-solid separator; the inlet of the pretreatment fluidizer is set at the upper part of the pretreatment feed chamber; the outlet of the pretreatment fluidizer is set at the pretreatment discharge chamber
  • the upper part of the reducing fluidizer is connected to the feed inlet of the reducing fluidizer; the reducing fluidizer is provided with a reducing baffle to separate the reducing fluidizer into a reducing feed chamber and a reducing discharge chamber.
  • the top edge of the reducing baffle is connected to The top plate of the reduction fluidizer is connected, the two sides of the reduction baffle are connected to the side walls of the reduction fluidizer, and the control between the bottom edge of the reduction baffle and the bottom plate of the reduction fluidizer is used as a reduction channel; reduction feed The bottom of the chamber and the reduction discharge chamber are respectively provided with a third air inlet and a fourth air inlet; the feed inlet of the reducing fluidizer is set at the upper part of the reducing feed chamber, and the outlet of the reducing fluidizer is set at Reduce the upper part of the discharge chamber and communicate with the feed port of the cooler; the discharge port of the cooler is opposite to the collection tank; the microwave cavity is assembled with the microwave generator;
  • the method is carried out as follows:
  • the generated microwave enters the microwave cavity, and the iron ore powder in the pretreatment fluidizer is heated to 800 ⁇ 1100°C through the microwave cavity, and the heated iron ore powder is fluidized from the pretreatment
  • the discharge port of the filter is discharged and enters the reducing fluidizer
  • the reduced material After the reduced material is cooled to below 100°C in the cooler, it continuously enters the collection tank from the discharge port of the cooler to obtain magnetized roasted iron ore powder.
  • the first air inlet is communicated with the first air storage tank through a pipe with a first valve
  • the second air inlet is communicated with the first air storage tank through a pipe with a second valve
  • the third air inlet communicates with the second gas storage tank through a pipeline with a third valve and a fourth valve
  • the fourth air inlet communicates with the second air tank through a pipeline with a fifth valve and a fourth valve.
  • the gas storage tank is connected, and the fourth air inlet is also connected with the third gas storage tank through a pipeline with a sixth valve.
  • the discharge port of the gas-solid separator is opposite to the feed bin.
  • the microwave generating device is composed of a waveguide, a magnetron and an antenna cap.
  • the waveguide is connected to the power supply through a wire.
  • the waveguide is located under the magnetron.
  • the magnetron is equipped with a microwave power meter.
  • the antenna cap under the magnetron is inserted Inside the waveguide.
  • the top of the pretreatment fluidizer, the reduction vulcanizer and the cooler are respectively provided with a first thermocouple, a second thermocouple and a third thermocouple, the first thermocouple, the second thermocouple and the third thermocouple They are respectively connected with the thermometer through data lines; wherein the first thermocouple is located in the pretreatment discharge chamber, and the second thermocouple is located in the reduction discharge chamber.
  • the above-mentioned cooler is a tube heat exchanger, and the cooling medium is water.
  • the volume ratio of the aforementioned pretreatment feed chamber to the pretreatment discharge chamber is 1:(4-8), and the height ratio of the pretreatment baffle to the pretreatment fluidizer is 1:(1 ⁇ 1.5); reduction feed
  • the volume ratio of the chamber to the reduction discharging chamber is 1: (4-8), and the height ratio of the reduction baffle to the reduction fluidizer is 1: (1 to 1.5).
  • the volume ratio of the aforementioned pretreatment fluidizer and reducing fluidizer is 1:1.
  • step 2 above the solid materials separated by the gas-solid separator enter the feed silo.
  • the iron grade of the above-mentioned iron ore is 10 to 58%.
  • to crush and grind the complex refractory iron ore is to first crush the complex refractory iron ore to a particle size ⁇ 1mm, and then grind it to a particle size ⁇ 0.074mm, which accounts for 70 ⁇ 90% is made into iron ore powder.
  • the above-mentioned protective gas is N 2 or CO 2 and is stored in the first gas storage tank and the second gas storage tank;
  • the reducing gas is CO, H 2 , CH 4 or water gas, and is stored in the third gas storage tank.
  • the residence time of the iron ore powder in the pretreatment fluidizer is 20-60 min.
  • the time for the heated iron ore powder to undergo reduction magnetization roasting in the reducing fluidizer is 20-60 minutes.
  • the volume ratio of the amount of reducing gas introduced to the amount of protective gas introduced into the reducing feed chamber is 1:9 ⁇ 4 : 6.
  • the obtained magnetized roasted iron ore powder is ground to a particle size of ⁇ 0.038mm, which accounts for 40-80% of the total mass, and then subjected to weak magnetic separation under the condition of a magnetic field strength of 80-100kA/m to obtain magnetic separation iron Concentrate, whose iron grade is ⁇ 61%.
  • the iron recovery rate of the magnetic separation iron concentrate relative to the iron ore is ⁇ 88%.
  • the ratio of the total volume of the protective gas passed into the pretreatment feed chamber and the pretreatment discharge chamber per unit time to the mass of the iron ore powder passed into the pretreatment feed chamber is 1-10m 3 / kg, wherein the volume ratio of the protective gas passing into the pretreatment feed chamber to the pretreatment discharge chamber is 1:(2 ⁇ 4).
  • the protective gas is passed into the reduction feed chamber and the reduction discharge chamber.
  • the volume flow ratio of the protective gas is 1: (1.5-2); the ratio of the volume of the protective gas passed into the reduction feed chamber per unit time to the mass of the iron ore powder entering the pretreatment feed chamber is 1-10m 3 /kg.
  • the microwave continuous suspension roasting device used in addition to focusing on the advantages of fluidized roasting and microwave heating, compared with the microwave-fluidized intermittent roasting device that has been applied for, the device can realize the simulation of industrial continuous test.
  • the level of equipment automation and intelligence has been greatly improved.
  • Figure 1 is a schematic structural diagram of a microwave continuous suspension roasting system in an embodiment of the present invention
  • the material of the pretreatment fluidizer and the pretreatment baffle in the embodiment of the present invention is quartz.
  • the material of the reducing fluidizer and the reducing baffle in the embodiment of the present invention is stainless steel, and the exterior is wrapped with insulation cotton.
  • the power control range of the microwave power meter used in the embodiment of the present invention is 50-2400W.
  • the material of the feed bin, gas-solid separator, microwave cavity, reducing fluidizer, cooler and collection tank in the embodiment of the present invention is stainless steel.
  • thermocouple in the embodiment of the present invention is 0-1100°C.
  • thermometer used in the embodiment of the present invention is a digital display thermometer.
  • the waveguide model used in the embodiment of the present invention is BJ26.
  • the model of the magnetron used in the embodiment of the present invention is 2M343K.
  • the material of the antenna cap used in the embodiment of the present invention is stainless steel.
  • the microwave frequency in the embodiment of the present invention is 2450 ⁇ 25 MHz.
  • the flow rate of the protective gas is 0.1-20 m 3 /h; the flow rate of the reducing gas is 0.1-20 m 3 /h.
  • the dissociation degree of the roasted iron ore powder is increased by more than 3%, and the grindability is increased by more than 3% (compared to the traditional resistance heat conduction heating or heat convection heating-fluidized roasting method).
  • the iron grade of the magnetic separation iron concentrate in the embodiment of the present invention is 60-70%.
  • the structure of the microwave continuous suspension roasting system is shown in Figure 1, including a feed bin 1, a pretreatment fluidizer 2, a microwave cavity 8, a microwave generator 5, a reducing fluidizer 17, a cooler 18 and a collection tank 19;
  • the discharge port at the bottom of the feed silo 1 is connected to the feed port of the pretreatment fluidizer 2.
  • the pretreatment fluidizer 2 is sheathed with a microwave cavity 8 and a pretreatment baffle is installed inside to connect the pretreatment fluidizer 2
  • the interior is divided into a pretreatment feed chamber and a pretreatment discharge chamber.
  • the top edge of the pretreatment baffle is connected to the top plate of the pretreatment fluidizer 2, and the two sides of the pretreatment baffle are connected to the pretreatment fluidizer 2.
  • the side walls are connected, and the gap between the bottom edge of the pretreatment baffle and the bottom plate of the pretreatment fluidizer 2 serves as the pretreatment channel;
  • the bottoms of the pretreatment feed chamber and the pretreatment discharge chamber are respectively provided with a first air inlet and a second air inlet, and the top of the pretreatment feed chamber is provided with an air outlet 15 and a gas-solid separator 14 inlet Connected; the gas outlet of the gas-solid separator 14 is connected with an exhaust pipe 13;
  • the feed port of the pretreatment fluidizer 2 is set at the upper part of the pretreatment feed chamber; the discharge port of the pretreatment fluidizer 2 is set at the upper part of the pretreatment discharge chamber, and is connected to the feed inlet of the reduction fluidizer 17 Mouth connected
  • the reduction fluidizer 17 is provided with a reduction baffle to separate the reduction fluidizer 17 into a reduction feed chamber and a reduction discharge chamber.
  • the top edge of the reduction baffle is connected to the top plate of the reduction fluidizer 17, and the reduction baffle
  • the two sides are connected with the side walls of the reducing fluidizer 17, and the control between the bottom edge of the reducing baffle and the bottom plate of the reducing fluidizer 17 serves as a reducing channel;
  • the bottoms of the reduction feed chamber and the reduction discharge chamber are respectively provided with a third air inlet and a fourth air inlet;
  • the feed inlet of the reducing fluidizer 17 is arranged at the upper part of the reducing feed chamber, and the outlet of the reducing fluidizer 17 is arranged at the upper part of the reducing discharge chamber and communicates with the inlet of the cooler 18;
  • the discharge port of the cooler 18 is opposite to the collection tank 19;
  • the microwave cavity 8 and the microwave generating device 5 are assembled together;
  • the first air inlet is in communication with the first gas tank 12 through a pipe with a first valve 10
  • the second air inlet is in communication with the first air tank 12 through a pipe with a second valve 11
  • the gas in the tank 12 is N 2 ;
  • the third air inlet is in communication with the second gas storage tank 27 through a pipe with a third valve 21 and a fourth valve 23 connected in series, and the fourth air inlet is connected with a fifth valve 20 and a fourth valve 23 connected in series.
  • the pipeline is connected to the second gas storage tank 27, and the fourth air inlet is also connected to the third gas storage tank 28 through a pipeline with a sixth valve 22;
  • the gas in the second gas storage tank 27 is N 2
  • the gas in the third gas storage tank 28 is CO;
  • the discharge port of the gas-solid separator 14 is opposite to the feed bin 1;
  • the microwave generating device 5 is composed of a waveguide 7, a magnetron 4, and an antenna cap 6.
  • the waveguide 7 is connected to the power supply 9 through a wire.
  • the waveguide 7 is located under the magnetron 4, and the magnetron 4 is equipped with a microwave power regulator 3.
  • the antenna cap 6 under the control tube 4 is inserted into the waveguide 7;
  • thermocouple 24 The tops of the pretreatment fluidizer 2, the reduction vulcanizer 17 and the cooler 18 are respectively provided with a first thermocouple 24, a second thermocouple 25 and a third thermocouple 26, the first thermocouple 24, the second thermocouple 25 and The third thermocouple 26 is respectively connected to the thermometer 16 through a data line; wherein the first thermocouple 24 is located in the pretreatment discharge chamber, and the second thermocouple 25 is located in the reduction discharge chamber;
  • the cooler 18 is a tubular heat exchanger, and the cooling medium is water;
  • the volume ratio of the pretreatment feed chamber to the pretreatment discharge chamber is 1:6, the height ratio of the pretreatment baffle to the pretreatment fluidizer 2 is 1:1.1; the volume ratio of the reduction feed chamber to the reduction discharge chamber 1:6, the height ratio of the reduction baffle to the reduction fluidizer 17 is 1:1.1;
  • the volume ratio of the pretreatment fluidizer 2 to the reducing fluidizer 17 is 1:1;
  • the method is:
  • To crush and grind the complex refractory iron ore is to first crush the complex refractory iron ore to a particle size of ⁇ 1mm, and the part that is ground to a particle size of ⁇ 0.074mm accounts for 80% of the total mass to produce iron ore powder. Then it is poured into the feed silo, and is continuously transported to the pretreatment fluidizer through the feed silo; the complex refractory iron ore used is a hematite-limonite type complex refractory iron ore from a certain place in Yunnan, with iron grade 35.25%, with FeO 9.24% and SiO 2 49.41% by mass percentage;
  • the protective gas is introduced into the pretreatment feed chamber and the pretreatment discharge chamber through the first air inlet and the second air inlet respectively, so that the iron ore powder in the pretreatment fluidizer is in a fluidized state, and the protective gas It is discharged from the gas outlet on the top of the pretreatment feed chamber, and part of the iron ore powder is discharged with the protective gas into the gas-solid separator; the solid material separated by the gas-solid separator enters the feeding bin, and the gas material separated by the gas-solid separator It is discharged through the exhaust pipe; the ratio of the total volume of the protective gas passing into the pretreatment feed chamber and the pretreatment discharge chamber per unit time to the mass of iron ore powder passing into the pretreatment feed chamber is 4m 3 /kg, The volume ratio of the protective gas passing into the pretreatment feed chamber to the pretreatment discharge chamber is 1:3;
  • the generated microwave enters the microwave cavity, and heats the iron ore powder in the pretreatment fluidizer to 900°C through the microwave cavity, and the heated iron ore powder is discharged from the pretreatment fluidizer Outlet and enter the reducing fluidizer;
  • the residence time of iron ore powder in the pretreatment fluidizer is 45min; when the third air inlet and the fourth air inlet respectively pass into the reduction feed chamber and the reduction discharge chamber
  • the volume flow ratio of the protective gas passing into the reduction feed chamber and the reduction discharge chamber is 1:1.5; the volume of the protective gas passing into the reduction feed chamber per unit time and the pretreatment
  • the mass ratio of the iron ore powder in the feeding chamber is 4.5m 3 /kg;
  • the protective gas Pass the protective gas into the reduction feed chamber and the reduction discharge chamber through the third air inlet and the fourth air inlet respectively, so that the heated iron ore powder in the reducing fluidizer is in a fluidized state; when heated When the temperature of the later iron ore powder drops to 550°C, the reducing gas is introduced into the reduction discharge chamber through the fourth air inlet, and the iron ore powder in the discharge chamber is reduced and magnetized and roasted to generate reducing materials and reducing gas. Enter the cooler; the heated iron ore powder undergoes reduction and magnetization roasting in the reducing fluidizer for 35 minutes; when the reducing gas is introduced into the reduction discharge chamber, the amount of reducing gas introduced and the reduction feed chamber The amount of protective gas introduced is 1:9 by volume;
  • the reduced material After the reduced material is cooled to below 100°C in the cooler, it continuously enters the collection tank from the discharge port of the cooler to obtain magnetized roasted iron ore powder;
  • the obtained magnetized roasted iron ore powder is ground to a particle size of ⁇ 0.038mm, which accounts for 40% of the total mass, and then subjected to weak magnetic separation under the condition of a magnetic field strength of 90kA/m to obtain a magnetically separated iron concentrate with an iron grade of 62.1% ;
  • the iron recovery rate of magnetic separation iron concentrate relative to iron ore is 88.5%.
  • the gas in the first gas storage tank is CO 2 ;
  • the gas in the second gas storage tank is CO 2
  • the gas in the third gas storage tank is H 2 ;
  • the volume ratio of the pretreatment feed chamber and the pretreatment discharge chamber is 1:5, the height ratio of the pretreatment baffle and the pretreatment fluidizer is 1:1; the reduction of the feed chamber and the reduction discharge chamber The volume ratio is 1:5, and the height ratio of the reduction baffle to the reduction fluidizer is 1:1;
  • the part of the iron ore powder with a particle size ⁇ 0.074mm accounts for 70% of the total mass, and the iron grade of the iron ore is 15.1%;
  • the ratio of the total volume of protective gas passing into the pretreatment feed chamber and the pretreatment discharge chamber per unit time to the mass of the iron ore powder passing into the pretreatment feed chamber is 5.5m 3 /kg, where The volume ratio of the protective gas entering the pretreatment feed chamber to the pretreatment discharge chamber is 1:4;
  • the iron ore powder in the pretreatment fluidizer is heated to 1100°C through the microwave cavity; the residence time of the iron ore powder in the pretreatment fluidizer is 20min; when the third and fourth air inlets When the protective gas is passed into the reduction feed chamber and the reduction discharge chamber respectively, the volume flow ratio of the protective gas passed into the reduction feed chamber to the reduction discharge chamber is 1:2; the reduction is passed in the unit time The ratio of the volume of the protective gas in the feeding chamber to the mass of the iron ore powder entering the pretreatment feeding chamber is 6m 3 /kg;
  • the reducing gas is introduced into the reduction discharge chamber through the fourth air inlet, and the iron ore powder in the discharge chamber is reduced and magnetized and roasted;
  • the heated iron ore powder undergoes reduction magnetization roasting in the reducing fluidizer for 25 minutes;
  • the reducing gas is introduced into the reducing discharge chamber, the amount of reducing gas introduced and the protective nature of the reducing inlet chamber
  • the gas flow rate is 4:6 by volume;
  • the obtained magnetized roasted iron ore powder is ground to a particle size of ⁇ 0.038mm accounting for 80% of the total mass, and then subjected to weak magnetic separation under the condition of a magnetic field strength of 100kA/m to obtain a magnetically separated iron concentrate.
  • the grade is 63.3%; the iron recovery rate of magnetic separation iron concentrate relative to iron ore is 89.4%.
  • the gas in the third gas storage tank is CH 4 ;
  • the volume ratio of the pretreatment feed chamber and the pretreatment discharge chamber is 1:8, the height ratio of the pretreatment baffle and the pretreatment fluidizer is 1:1.5; the reduction of the feed chamber and the reduction discharge chamber The volume ratio is 1:8, and the height ratio of the reduction baffle to the reduction fluidizer is 1:1.5;
  • the part of the iron ore powder with a particle size ⁇ 0.074mm accounts for 90% of the total mass, and the iron grade of the iron ore is 29.6%;
  • the ratio of the total volume of protective gas passing into the pretreatment feed chamber and the pretreatment discharge chamber per unit time to the mass of iron ore powder passing into the pretreatment feed chamber is 7.5m 3 /kg, where The volume ratio of the protective gas entering the pretreatment feed chamber to the pretreatment discharge chamber is 1:2;
  • the iron ore powder in the pretreatment fluidizer is heated to 1000°C through the microwave cavity; the residence time of the iron ore powder in the pretreatment fluidizer is 30min; when the third and fourth air inlets When the protective gas is passed into the reduction feed chamber and the reduction discharge chamber respectively, the volume flow ratio of the protective gas passed into the reduction feed chamber to the reduction discharge chamber is 1:1.8; the reduction is passed in the unit time
  • the ratio of the volume of the protective gas in the feeding chamber to the mass of the iron ore powder entering the pretreatment feeding chamber is 3.5m 3 /kg;
  • the obtained magnetized roasted iron ore powder is ground to a particle size of ⁇ 0.038mm accounting for 50% of the total mass, and then subjected to weak magnetic separation under the condition of a magnetic field strength of 80kA/m to obtain a magnetically separated iron concentrate.
  • the grade is 65.4%; the iron recovery rate of the magnetic separation iron concentrate relative to the iron ore is 89.2%.
  • the gas in the first gas storage tank is CO 2 ;
  • the gas in the second gas storage tank is CO 2
  • the gas in the third gas storage tank is water gas;
  • the volume ratio of the pretreatment feed chamber to the pretreatment discharge chamber is 1:4, and the height ratio of the pretreatment baffle to the pretreatment fluidizer is 1:1.3; the reduction of the feed chamber and the reduction discharge chamber The volume ratio is 1:4, and the height ratio of the reduction baffle to the reduction fluidizer is 1:1.3;
  • the part of the iron ore powder with a particle size ⁇ 0.074mm accounts for 85% of the total mass, and the iron grade of the iron ore is 47.3%;
  • the ratio of the total volume of protective gas passing into the pretreatment feed chamber and the pretreatment discharge chamber per unit time to the mass of iron ore powder passing into the pretreatment feed chamber is 2.5m 3 /kg, where The volume ratio of the protective gas entering the pretreatment feed chamber to the pretreatment discharge chamber is 1:2.5;
  • the iron ore powder in the pretreatment fluidizer is heated to 800°C through the microwave cavity; the residence time of the iron ore powder in the pretreatment fluidizer is 60min; when the third air inlet and the fourth air inlet When the protective gas is introduced into the reduction feed chamber and the reduction discharge chamber respectively, the volume flow ratio of the protective gas into the reduction feed chamber to the reduction discharge chamber is 1:1.6; the reduction is introduced per unit time The ratio of the volume of the protective gas in the feeding chamber to the mass of the iron ore powder entering the pretreatment feeding chamber is 7m 3 /kg;
  • the obtained magnetized roasted iron ore powder is ground to a particle size of ⁇ 0.038mm accounting for 60% of the total mass, and then subjected to weak magnetic separation under the condition of a magnetic field strength of 95kA/m to obtain a magnetic separation iron concentrate.
  • the grade is 62.8%; the iron recovery rate of the magnetic separation iron concentrate relative to the iron ore is 86.1%.

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Abstract

一种强化复杂难选铁矿石解离的微波连续悬浮焙烧方法，采用微波连续悬浮焙烧系统，按以下步骤进行：（1）将复杂难选铁矿石破碎磨细倒入给料仓，输送到预处理流化器；（2）向预处理进料室和预处理出料室内通入保护性气体，使铁矿粉处于流化状态；（3）开启微波发生装置，通过微波腔体加热，然后进入还原流化器；（4）分别向还原进料室和还原出料室内通入保护性气体；当温度降低至450~650℃时，通入还原性气体进行还原磁化焙烧，还原物料进入冷却器；（5）降温至100℃以下 后进入收集槽。本发明的方法能够显著提高矿物单体解离度和可磨度，实现了复杂难选铁矿石的资源化和高效化的开发利用。

Description

强化复杂难选铁矿石解离的微波连续悬浮焙烧方法 技术领域
本发明属于矿物加工技术领域，具体涉及到一种强化复杂难选铁矿石解离的微波连续悬浮焙烧方法。
背景技术
近年来我国钢铁工业迅速发展，极大的促进铁矿石的需求，我国铁矿资源储量丰富，2017年底，我国查明铁矿石资源储量为848.88亿t；然而，我国铁矿资源整体呈品位低、结晶粒度细、矿物组成复杂的特点，致使大量的铁矿资源未能得到有效开发利用，这不得不使钢铁工业依赖进口；2017年，我国进口铁矿石10.75亿t，增长7.5％，对外依存度超过86％，随着国际铁矿石供需关系的改变，造成国内铁矿石价格大幅下跌和铁矿山严重亏损；因此，加强复杂难选铁矿石的高效开发利用，对降低我国铁矿石对外依存度、促进我国钢铁工业健康发展具有重要意义。
近年来，围绕复杂难选铁矿石的高效开发利用，国内外众多研究单位开展了大量的基础研究和技术开发工作，其中以选冶联合即磁化焙烧-磁选工艺效果最为突出，而磁化焙烧-磁选工艺中应用最为成功的当属悬浮磁化焙烧-磁选工艺；其中，东北大学自主研发的预富集悬浮焙烧磁选技术，以湖北五峰状赤铁矿、渝东典型沉积型赤褐铁矿、鞍钢东部尾矿、东鞍山铁矿石及酒钢粉矿等为原料，开展了系统的PSRM实验室及中试试验，均获得良好的分选指标；在此基础之上，如何更好的实现提高矿物单体解离和可磨度、节能降耗和提高分选指标成为研究的重点和难点；在冶金工程应用过程中，微波焙烧相较于传统焙烧表现出巨大的优势，微波焙烧速率比传统焙烧速率高3.97～7.15倍，微波所特有的选择性加热优势，使得有用矿物与脉石矿物吸波特性存在较大差异，进而在矿物结合面产生内应力而形成裂纹和裂缝，能够显著提高矿物单体解离度和可磨度，更为节能降耗，选别效果更为显著。
众多专家学者针对微波焙烧开展了大量的基础研究，主要研究方向集中在矿物 微波预处理、矿物吸波特性、矿物静态碳热还原微波焙烧等，针对流态化状态下的微波焙烧鲜有研究，依据目前利用悬浮焙烧-磁选工艺高效开发利用复杂难选铁矿石的研究现状，如何更好的实现提高矿物单体解离和可磨度、分选指标和节能降耗，在此基础之上，能够提高设备自动化和智能化水平，将是未来的研究重点和难点。
发明概述
技术问题
问题的解决方案
技术解决方案
本发明的目的是提供一种强化复杂难选铁矿石解离的微波连续悬浮焙烧方法，通过微波蓄热预处理和悬浮磁化焙烧组合的新方式，对铁矿石物料进行选择性快速蓄热、连续性悬浮焙烧、增强铁矿物单体解离度，进而增大矿物分选指标，实现复杂难选铁矿石高效综合开发利用。
本发明的方法是采用微波连续悬浮焙烧系统，该系统包括给料仓、预处理流化器、微波腔体、微波发生装置、还原流化器、冷却器和收集槽；给料仓底部的出料口与预处理流化器的进料口连通，预处理流化器外部套有微波腔体，内部设有预处理挡板将预处理流化器内部分隔为预处理进料室和预处理出料室，预处理挡板的顶边与预处理流化器的顶板连接，预处理挡板的两个侧边与预处理流化器的侧壁连接，预处理挡板的底边与预处理流化器的底板之间的空隙作为预处理通道；预处理进料室和预处理出料室的底部分别设有第一进气口和第二进气口，预处理进料室的顶部设有出气口与气固分离器的进料口连通；预处理流化器的进料口设置在预处理进料室的上部；预处理流化器的出料口设置在预处理出料室的上部，并与还原流化器的进料口连通；还原流化器内部设有还原挡板将还原流化器内部分隔为还原进料室和还原出料室，还原挡板的顶边与还原流化器的顶板连接，还原挡板的两个侧边与还原流化器的侧壁连接，还原挡板的底边与还原流化器的底板之间的控制作为还原通道；还原进料室和还原出料室的底部分别设有第三进气口和第四进气口；还原流化器的进料口设置在还原进料室的上部，还原流化器的出料口设置在还原出料室的上部，并与冷却器 的进料口连通；冷却器的出料口与收集槽相对；微波腔体与微波发生装置装配在一起；
方法按以下步骤进行：
1、将复杂难选铁矿石破碎并磨细制成铁矿粉，然后倒入给料仓，经过给料仓连续输送到预处理流化器内；
2、通过第一进气口和第二进气口分别向预处理进料室和预处理出料室内通入保护性气体，使预处理流化器内的铁矿粉处于流化状态，保护性气体从预处理进料室顶部的出气口排出，部分铁矿粉随保护性气体排出进入气固分离器；
3、开启微波发生装置，产生的微波进入微波腔体，并通过微波腔体对预处理流化器内的铁矿粉加热至800～1100℃，被加热后的铁矿粉从预处理流化器的出料口排出，进入还原流化器；
4、通过第三进气口和第四进气口分别向还原进料室和还原出料室内通入保护性气体，使还原流化器内被加热后的铁矿粉处于流化状态；当被加热后的铁矿粉的温度降低至450～650℃时，通过第四进气口向还原出料室内通入还原性气体，对出料室内的铁矿粉进行还原磁化焙烧，生成还原物料随还原性气体进入冷却器；
5、还原物料在冷却器内降温至100℃以下后，从冷却器出料口连续进入收集槽，获得磁化焙烧铁矿粉。
上述方法中，第一进气口通过带有第一阀门的管道与第一储气罐连通，第二进气口通过带有第二阀门的管道与第一储气罐连通。
上述方法中，第三进气口通过带有第三阀门和第四阀门的管道与第二储气罐连通，第四进气口通过带有第五阀门的和第四阀门的管道与第二储气罐连通，第四进气口还通过带有第六阀门的管道与第三储气罐连通。
上述方法中，气固分离器的出料口与给料仓相对。
上述方法中，微波发生装置由波导、磁控管和天线帽组成，波导通过导线与电源连接，波导位于磁控管下方，磁控管上装配有微波功率仪，磁控管下方的天线帽插入波导内。
上述方法中，预处理流化器、还原硫化器和冷却器的顶部分别设有第一热电偶 、第二热电偶和第三热电偶，第一热电偶、第二热电偶和第三热电偶分别通过数据线与测温仪连接；其中第一热电偶位于预处理出料室内，第二热电偶位于还原出料室内。
上述的冷却器为管式换热器，冷却介质为水。
上述的预处理进料室与预处理出料室的容积比为1∶(4～8)，预处理挡板与预处理流化器的高度比为1∶(1～1.5)；还原进料室与还原出料室的容积比为1∶(4～8)，还原挡板与还原流化器的高度比为1∶(1～1.5)。
上述的预处理流化器与还原流化器的容积比为1∶1。
上述的步骤2中，气固分离器分离出的固体物料进入给料仓。
上述的铁矿石铁品位10～58％。
上述的步骤1中，将复杂难选铁矿石破碎并磨细是先将复杂难选铁矿石破碎至粒径≤1mm，然后磨细至粒径≤0.074mm的部分占总质量的70～90％，制成铁矿粉。
上述的保护性气体为N 2或CO 2，储存在第一储气罐和第二储气罐内；还原性气体为CO、H 2、CH 4或水煤气，储存在第三储气罐内。
上述的步骤3中，铁矿粉在预处理流化器内的停留时间为20～60min。
上述的步骤4中，被加热后的铁矿粉在还原流化器进行还原磁化焙烧的时间为20～60min。
上述的步骤4中，当向还原出料室通入还原性气体时，还原性气体的通入量与还原进料室通入的保护性气体的通入量按体积比为1∶9～4∶6。
上述方法中，当还原磁化焙烧结束后，停止向还原出料室通入还原性气体，关闭微波发生装置；通过向还原流化器和预处理流化器内通入保护性气体降温；当还原流化器和预处理流化器的温度低于300℃时，停止通入保护性气体。
上述方法中，获得的磁化焙烧铁矿粉磨矿至粒径≤0.038mm的部分占总质量的40～80％，然后在磁场强度80～100kA/m条件下进行弱磁选，获得磁选铁精矿，其铁品位≥61％。
上述方法中，磁选铁精矿相对于铁矿石的铁回收率≥88％。
上述的步骤2中，单位时间内通入预处理进料室和预处理出料室的保护性气体 总体积与通入预处理进料室的铁矿粉的质量的比例为1～10m 3/kg，其中通入预处理进料室与通入预处理出料室的保护性气体的体积比为1∶(2～4)。
上述的步骤3中，当第三进气口和第四进气口分别向还原进料室和还原出料室内通入保护性气体时，通入还原进料室与通入还原出料室的保护性气体的体积流量比为1∶(1.5～2)；单位时间内通入还原进料室的保护性气体的体积与进入预处理进料室的铁矿粉的质量的比例为1～10m 3/kg。
发明的有益效果
有益效果
与现有技术相比，本发明的突出优点包括：
1、通过微波所特有的选择性加热优势，使得有用矿物与脉石矿物吸波特性存在较大差异，进而在矿物结合面产生内应力而形成裂纹和裂缝，能够显著提高矿物单体解离度和可磨度；
2、采用微波连续悬浮焙烧装置，选别效果更为显著，实现了复杂难选铁矿石的资源化和高效化的开发利用；
3、所用微波连续悬浮焙烧装置，除集中了流态化焙烧和微波加热的优势之外，与已经申请的微波-流态化间歇性焙烧装置相比，该装置可实现工业连续试验仿真模拟，装置自动化和智能化水平大幅提高。
对附图的简要说明
附图说明
图1为本发明实施例中的微波连续悬浮焙烧系统结构示意图；
图中，1、给料仓，2、预处理流化器，3、微波功率调节仪，4、磁控管，5、微波发生装置，6、天线帽，7、波导，8、微波腔体，9、电源，10、第一阀门，11、第二阀门，12、第一储气罐，13、排气管，14、气固分离器，15、出气口，16、测温仪，17、还原流化器，18、冷却器，19、收集槽，20、第五阀门，21、第三阀门。22、第六阀门，23、第四阀门，24、第一热电偶，25、第二热电偶，26、第三热电偶，27、第二储气罐，28、第三储气罐。
发明实施例
本发明的实施方式
以下结合实例对本发明做进一步说明。
本发明实施例中的预处理流化器和预处理挡板的材质为石英。
本发明实施例中的还原流化器和还原挡板的材质是不锈钢，并且外部包裹有保温棉。
本发明实施例中采用的微波功率仪的功率调控范围为50～2400W。
本发明实施例中的给料仓、气固分离器、微波腔体、还原流化器、冷却器和收集槽的材质为不锈钢。
本发明实施例中的热电偶的测温范围为0～1100℃。
本发明实施例中采用的测温仪为数显测温仪。
本发明实施例中采用的波导型号为BJ26。
本发明实施例中采用的磁控管的型号为2M343K。
本发明实施例中采用的天线帽材质为不锈钢。
本发明实施例中的微波频率为2450±25MHz。
本发明实施例中保护性气体的流速为0.1～20m 3/h；还原性气体的流速为0.1～20m 3/h。
本发明实施例中焙烧铁矿粉单体解离度提高3％以上，可磨度提高3％以上(相较于传统电阻热传导加热或热对流加热-流态化焙烧方法)。
本发明实施例中磁选铁精矿的铁品位60～70％。
实施例1
微波连续悬浮焙烧系统结构如图1所示，包括给料仓1、预处理流化器2、微波腔体8、微波发生装置5、还原流化器17、冷却器18和收集槽19；
给料仓1底部的出料口与预处理流化器2的进料口连通，预处理流化器2外部套有微波腔体8，内部设有预处理挡板将预处理流化器2内部分隔为预处理进料室和预处理出料室，预处理挡板的顶边与预处理流化器2的顶板连接，预处理挡板的两个侧边与预处理流化器2的侧壁连接，预处理挡板的底边与预处理流化器2的底板之间的空隙作为预处理通道；
预处理进料室和预处理出料室的底部分别设有第一进气口和第二进气口，预处 理进料室的顶部设有出气口15与气固分离器14的进料口连通；气固分离器14的出气口连接有排气管13；
预处理流化器2的进料口设置在预处理进料室的上部；预处理流化器2的出料口设置在预处理出料室的上部，并与还原流化器17的进料口连通；
还原流化器17内部设有还原挡板将还原流化器17内部分隔为还原进料室和还原出料室，还原挡板的顶边与还原流化器17的顶板连接，还原挡板的两个侧边与还原流化器17的侧壁连接，还原挡板的底边与还原流化器17的底板之间的控制作为还原通道；
还原进料室和还原出料室的底部分别设有第三进气口和第四进气口；
还原流化器17的进料口设置在还原进料室的上部，还原流化器17的出料口设置在还原出料室的上部，并与冷却器18的进料口连通；
冷却器18的出料口与收集槽19相对；
微波腔体8与微波发生装置5装配在一起；
第一进气口通过带有第一阀门10的管道与第一储气罐12连通，第二进气口通过带有第二阀门11的管道与第一储气罐12连通；第一储气罐12内的气体为N 2；
第三进气口通过带有串联的第三阀门21和第四阀门23的管道与第二储气罐27连通，第四进气口通过带有串联的第五阀门20的和第四阀门23的管道与第二储气罐27连通，第四进气口还通过带有第六阀门22的管道与第三储气罐28连通；
第二储气罐27内的气体为N 2，第三储气罐28内的气体为CO；
气固分离器14的出料口与给料仓1相对；
微波发生装置5由波导7、磁控管4和天线帽6组成，波导7通过导线与电源9连接，波导7位于磁控管4下方，磁控管4上装配有微波功率调节仪3，磁控管4下方的天线帽6插入波导7内；
预处理流化器2、还原硫化器17和冷却器18的顶部分别设有第一热电偶24、第二热电偶25和第三热电偶26，第一热电偶24、第二热电偶25和第三热电偶26分别通过数据线与测温仪16连接；其中第一热电偶24位于预处理出料室内，第二热电偶25位于还原出料室内；
冷却器18为管式换热器，冷却介质为水；
预处理进料室与预处理出料室的容积比为1∶6，预处理挡板与预处理流化器2的高度比为1∶1.1；还原进料室与还原出料室的容积比为1∶6，还原挡板与还原流化器17的高度比为1∶1.1；
预处理流化器2与还原流化器17的容积比为1∶1；
方法为：
将复杂难选铁矿石破碎并磨细是先将复杂难选铁矿石破碎至粒径≤1mm，磨细至粒径≤0.074mm的部分占总质量的80％，制成铁矿粉，然后倒入给料仓，经过给料仓连续输送到预处理流化器内；采用的复杂难选铁矿石为云南某地赤铁矿-褐铁矿型复杂难选铁矿石，铁品位35.25％，按质量百分比含FeO 9.24％，SiO 249.41％；
通过第一进气口和第二进气口分别向预处理进料室和预处理出料室内通入保护性气体，使预处理流化器内的铁矿粉处于流化状态，保护性气体从预处理进料室顶部的出气口排出，部分铁矿粉随保护性气体排出进入气固分离器；气固分离器分离出的固体物料进入给料仓，气固分离器分离出的气体物料经排气管排出；单位时间内通入预处理进料室和预处理出料室的保护性气体总体积与通入预处理进料室的铁矿粉的质量的比例为4m 3/kg，其中通入预处理进料室与通入预处理出料室的保护性气体的体积比为1∶3；
开启微波发生装置，产生的微波进入微波腔体，并通过微波腔体对预处理流化器内的铁矿粉加热至900℃，被加热后的铁矿粉从预处理流化器的出料口排出，进入还原流化器；铁矿粉在预处理流化器内的停留时间为45min；当第三进气口和第四进气口分别向还原进料室和还原出料室内通入保护性气体时，通入还原进料室与通入还原出料室的保护性气体的体积流量比为1∶1.5；单位时间内通入还原进料室的保护性气体的体积与进入预处理进料室的铁矿粉的质量的比例为4.5m 3/kg；
通过第三进气口和第四进气口分别向还原进料室和还原出料室内通入保护性气体，使还原流化器内被加热后的铁矿粉处于流化状态；当被加热后的铁矿粉的温度降低至550℃时，通过第四进气口向还原出料室内通入还原性气体，对出料室内的铁矿粉进行还原磁化焙烧，生成还原物料随还原性气体进入冷却器；被 加热后的铁矿粉在还原流化器进行还原磁化焙烧的时间为35min；当向还原出料室通入还原性气体时，还原性气体的通入量与还原进料室通入的保护性气体的通入量按体积比为1∶9；
还原物料在冷却器内降温至100℃以下后，从冷却器出料口连续进入收集槽，获得磁化焙烧铁矿粉；
当还原磁化焙烧结束后，停止向还原出料室通入还原性气体，关闭微波发生装置；通过向还原流化器和预处理流化器内通入保护性气体降温；当还原流化器和预处理流化器的温度低于300℃时，停止通入保护性气体；
获得的磁化焙烧铁矿粉磨矿至粒径≤0.038mm的部分占总质量的40％，然后在磁场强度90kA/m条件下进行弱磁选，获得磁选铁精矿，其铁品位62.1％；磁选铁精矿相对于铁矿石的铁回收率88.5％。
实施例2
系统结构同实施例1，不同点在于：
(1)第一储气罐内的气体为CO 2；第二储气罐内的气体为CO 2，第三储气罐内的气体为H 2；
(2)预处理进料室与预处理出料室的容积比为1∶5，预处理挡板与预处理流化器的高度比为1∶1；还原进料室与还原出料室的容积比为1∶5，还原挡板与还原流化器的高度比为1∶1；
方法同实施例1，不同点在于：
(1)铁矿粉中粒径≤0.074mm的部分占总质量的70％，铁矿石的铁品位15.1％；
(2)单位时间内通入预处理进料室和预处理出料室的保护性气体总体积与通入预处理进料室的铁矿粉的质量的比例为5.5m 3/kg，其中通入预处理进料室与通入预处理出料室的保护性气体的体积比为1∶4；
(3)通过微波腔体对预处理流化器内的铁矿粉加热至1100℃；铁矿粉在预处理流化器内的停留时间20min；当第三进气口和第四进气口分别向还原进料室和还原出料室内通入保护性气体时，通入还原进料室与通入还原出料室的保护性气体的体积流量比为1∶2；单位时间内通入还原进料室的保护性气体的体积与进 入预处理进料室的铁矿粉的质量的比例为6m 3/kg；
(4)当被加热后的铁矿粉的温度降低至600℃时，通过第四进气口向还原出料室内通入还原性气体，对出料室内的铁矿粉进行还原磁化焙烧；被加热后的铁矿粉在还原流化器进行还原磁化焙烧的时间为25min；当向还原出料室通入还原性气体时，还原性气体的通入量与还原进料室通入的保护性气体的通入量按体积比为4∶6；
(5)获得的磁化焙烧铁矿粉磨矿至粒径≤0.038mm的部分占总质量的80％，然后在磁场强度100kA/m条件下进行弱磁选，获得磁选铁精矿，其铁品位63.3％；磁选铁精矿相对于铁矿石的铁回收率89.4％。
实施例3
系统结构同实施例1，不同点在于：
(1)第三储气罐内的气体为CH 4；
(2)预处理进料室与预处理出料室的容积比为1∶8，预处理挡板与预处理流化器的高度比为1∶1.5；还原进料室与还原出料室的容积比为1∶8，还原挡板与还原流化器的高度比为1∶1.5；
方法同实施例1，不同点在于：
(1)铁矿粉中粒径≤0.074mm的部分占总质量的90％，铁矿石的铁品位29.6％；
(2)单位时间内通入预处理进料室和预处理出料室的保护性气体总体积与通入预处理进料室的铁矿粉的质量的比例为7.5m 3/kg，其中通入预处理进料室与通入预处理出料室的保护性气体的体积比为1∶2；
(3)通过微波腔体对预处理流化器内的铁矿粉加热至1000℃；铁矿粉在预处理流化器内的停留时间30min；当第三进气口和第四进气口分别向还原进料室和还原出料室内通入保护性气体时，通入还原进料室与通入还原出料室的保护性气体的体积流量比为1∶1.8；单位时间内通入还原进料室的保护性气体的体积与进入预处理进料室的铁矿粉的质量的比例为3.5m 3/kg；
(4)当被加热后的铁矿粉的温度降低至450℃时，通过第四进气口向还原出料室内通入还原性气体，对出料室内的铁矿粉进行还原磁化焙烧；被加热后的铁 矿粉在还原流化器进行还原磁化焙烧的时间为60min；当向还原出料室通入还原性气体时，还原性气体的通入量与还原进料室通入的保护性气体的通入量按体积比为3∶7；
(5)获得的磁化焙烧铁矿粉磨矿至粒径≤0.038mm的部分占总质量的50％，然后在磁场强度80kA/m条件下进行弱磁选，获得磁选铁精矿，其铁品位65.4％；磁选铁精矿相对于铁矿石的铁回收率89.2％。
实施例4
系统结构同实施例1，不同点在于：
(1)第一储气罐内的气体为CO 2；第二储气罐内的气体为CO 2，第三储气罐内的气体为水煤气；
(2)预处理进料室与预处理出料室的容积比为1∶4，预处理挡板与预处理流化器的高度比为1∶1.3；还原进料室与还原出料室的容积比为1∶4，还原挡板与还原流化器的高度比为1∶1.3；
方法同实施例1，不同点在于：
(1)铁矿粉中粒径≤0.074mm的部分占总质量的85％，铁矿石的铁品位47.3％；
(2)单位时间内通入预处理进料室和预处理出料室的保护性气体总体积与通入预处理进料室的铁矿粉的质量的比例为2.5m 3/kg，其中通入预处理进料室与通入预处理出料室的保护性气体的体积比为1∶2.5；
(3)通过微波腔体对预处理流化器内的铁矿粉加热至800℃；铁矿粉在预处理流化器内的停留时间60min；当第三进气口和第四进气口分别向还原进料室和还原出料室内通入保护性气体时，通入还原进料室与通入还原出料室的保护性气体的体积流量比为1∶1.6；单位时间内通入还原进料室的保护性气体的体积与进入预处理进料室的铁矿粉的质量的比例为7m 3/kg；
(4)当被加热后的铁矿粉的温度降低至650℃时，通过第四进气口向还原出料室内通入还原性气体，对出料室内的铁矿粉进行还原磁化焙烧；被加热后的铁矿粉在还原流化器进行还原磁化焙烧的时间为20min；当向还原出料室通入还原性气体时，还原性气体的通入量与还原进料室通入的保护性气体的通入量按体 积比为2∶8；
(5)获得的磁化焙烧铁矿粉磨矿至粒径≤0.038mm的部分占总质量的60％，然后在磁场强度95kA/m条件下进行弱磁选，获得磁选铁精矿，其铁品位62.8％；磁选铁精矿相对于铁矿石的铁回收率86.1％。

Claims (10)

  1. 一种强化复杂难选铁矿石解离的微波连续悬浮焙烧方法，其特征在于采用微波连续悬浮焙烧系统，该系统包括给料仓、预处理流化器、微波腔体、微波发生装置、还原流化器、冷却器和收集槽；给料仓底部的出料口与预处理流化器的进料口连通，预处理流化器外部套有微波腔体，内部设有预处理挡板将预处理流化器内部分隔为预处理进料室和预处理出料室，预处理挡板的顶边与预处理流化器的顶板连接，预处理挡板的两个侧边与预处理流化器的侧壁连接，预处理挡板的底边与预处理流化器的底板之间的空隙作为预处理通道；预处理进料室和预处理出料室的底部分别设有第一进气口和第二进气口，预处理进料室的顶部设有出气口与气固分离器的进料口连通；预处理流化器的进料口设置在预处理进料室的上部；预处理流化器的出料口设置在预处理出料室的上部，并与还原流化器的进料口连通；还原流化器内部设有还原挡板将还原流化器内部分隔为还原进料室和还原出料室，还原挡板的顶边与还原流化器的顶板连接，还原挡板的两个侧边与还原流化器的侧壁连接，还原挡板的底边与还原流化器的底板之间的控制作为还原通道；还原进料室和还原出料室的底部分别设有第三进气口和第四进气口；还原流化器的进料口设置在还原进料室的上部，还原流化器的出料口设置在还原出料室的上部，并与冷却器的进料口连通；冷却器的出料口与收集槽相对；微波腔体与微波发生装置装配在一起；
    方法按以下步骤进行：
    (1)将复杂难选铁矿石破碎并磨细制成铁矿粉，然后倒入给料仓，经过给料仓连续输送到预处理流化器内；
    (2)通过第一进气口和第二进气口分别向预处理进料室和预处理出料室内通入保护性气体，使预处理流化器内的铁矿粉处于流化状态，保护性气体从预处理进料室顶部的出气口排出，部分铁矿 粉随保护性气体排出进入气固分离器；
    (3)开启微波发生装置，产生的微波进入微波腔体，并通过微波腔体对预处理流化器内的铁矿粉加热至800～1100℃，被加热后的铁矿粉从预处理流化器的出料口排出，进入还原流化器；
    (4)通过第三进气口和第四进气口分别向还原进料室和还原出料室内通入保护性气体，使还原流化器内被加热后的铁矿粉处于流化状态；当被加热后的铁矿粉的温度降低至450～650℃时，通过第四进气口向还原出料室内通入还原性气体，对出料室内的铁矿粉进行还原磁化焙烧，生成还原物料随还原性气体进入冷却器；
    (5)还原物料在冷却器内降温至100℃以下 后，从冷却器出料口连续进入收集槽，获得磁化焙烧铁矿粉。
  2. 根据权利要求1所述的一种强化复杂难选铁矿石解离的微波连续悬浮焙烧方法，其特征在于所述的第一进气口通过带有第一阀门的管道与第一储气罐连通，第二进气口通过带有第二阀门的管道与第一储气罐连通。
  3. 根据权利要求1所述的一种强化复杂难选铁矿石解离的微波连续悬浮焙烧方法，其特征在于所述的第三进气口通过带有第三阀门和第四阀门的管道与第二储气罐连通，第四进气口通过带有第五阀门的和第四阀门的管道与第二储气罐连通，第四进气口还通过带有第六阀门的管道与第三储气罐连通。
  4. 根据权利要求1所述的一种强化复杂难选铁矿石解离的微波连续悬浮焙烧方法，其特征在于所述的微波发生装置由波导、磁控管和天线帽组成，波导通过导线与电源连接，波导位于磁控管下方，磁控管上装配有微波功率仪，磁控管下方的天线帽插入波导内。
  5. 根据权利要求1所述的一种强化复杂难选铁矿石解离的微波连续悬浮焙烧方法，其特征在于所述的预处理流化器、还原硫化器和冷却器的顶部分别设有第一热电偶、第二热电偶和第三热电偶，第一热电偶、第二热电偶和第三热电偶分别通过数据线与测温仪连 接；其中第一热电偶位于预处理出料室内，第二热电偶位于还原出料室内。
  6. 根据权利要求1所述的一种强化复杂难选铁矿石解离的微波连续悬浮焙烧方法，其特征在于所述的预处理进料室与预处理出料室的容积比为1∶(4～8)，预处理挡板与预处理流化器的高度比为1∶(1～1.5)；还原进料室与还原出料室的容积比为1∶(4～8)，还原挡板与还原流化器的高度比为1∶(1～1.5)。
  7. 根据权利要求1所述的一种强化复杂难选铁矿石解离的微波连续悬浮焙烧方法，其特征在于所述的铁矿石铁品位10～58％。
  8. 根据权利要求1所述的一种强化复杂难选铁矿石解离的微波连续悬浮焙烧方法，其特征在于所述的保护性气体为N 2或CO 2，还原性气体为CO、H 2、CH 4或水煤气。
  9. 根据权利要求1所述的一种强化复杂难选铁矿石解离的微波连续悬浮焙烧方法，其特征在于步骤(4)中，当向还原出料室通入还原性气体时，还原性气体的通入量与还原进料室通入的保护性气体的通入量按体积比为1∶9～4∶6。
  10. 根据权利要求1所述的一种强化复杂难选铁矿石解离的微波连续悬浮焙烧方法，其特征在于获得的磁化焙烧铁矿粉磨矿至粒径≤0.038mm的部分占总质量的40～80％，然后在磁场强度80～100kA/m条件下进行弱磁选，获得磁选铁精矿，其铁品位≥61％。
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