CN113981228A - Method for inhibiting ring formation in kiln and improving recovery rate of zinc - Google Patents
Method for inhibiting ring formation in kiln and improving recovery rate of zinc Download PDFInfo
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- 238000000034 method Methods 0.000 title claims abstract description 48
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- 238000011084 recovery Methods 0.000 title claims abstract description 41
- 238000007363 ring formation reaction Methods 0.000 title claims abstract description 27
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- 239000000463 material Substances 0.000 claims abstract description 65
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- 229910001341 Crude steel Inorganic materials 0.000 description 1
- 229910000805 Pig iron Inorganic materials 0.000 description 1
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- 230000009471 action Effects 0.000 description 1
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- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 1
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- VTYYLEPIZMXCLO-UHFFFAOYSA-L calcium carbonate Substances [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
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Images
Classifications
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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
- C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
- C22B7/02—Working-up flue dust
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B1/00—Preliminary treatment of ores or scrap
- C22B1/02—Roasting processes
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B19/00—Obtaining zinc or zinc oxide
- C22B19/30—Obtaining zinc or zinc oxide from metallic residues or scraps
-
- 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
- C22B5/00—General methods of reducing to metals
- C22B5/02—Dry methods smelting of sulfides or formation of mattes
- C22B5/10—Dry methods smelting of sulfides or formation of mattes by solid carbonaceous reducing agents
-
- 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
- C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
- C22B7/001—Dry processes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Abstract
The invention relates to a method for inhibiting ring formation in a kiln and improving the recovery rate of zinc, which is characterized in that iron and steel smelting dust is mixed with coke and a regulating material, wherein the regulating material is made of SiO2And the uniform compound formed by the CaO is actively pumped in the reduction roasting process, a sludge product of the zinc element is obtained by collecting through a flue gas recovery system, the roasted product is fed into an ore grinding-low-intensity magnetic separation recovery system after water quenching treatment, and iron ore concentrate and tailings are obtained after low-intensity magnetic separation. The invention can simultaneously realize more than 97 percent of zinc volatilization rate, more than 67 percent of iron ore concentrate with grade and 80 percent of material deposition on the ring forming surface in the rotary kiln, not only can effectively recover Zn element in the dust of steel smelting, but also can effectively reduce Zn elementLow energy consumption, reduced environmental pollution, increased cost rate and increased profit rate.
Description
Technical Field
The invention belongs to the field of comprehensive utilization of solid wastes in iron and steel smelting, and particularly relates to a method for inhibiting ring formation in a kiln and improving the recovery rate of zinc.
Background
The steel industry is an important prop industry of national economy, has wide industrial design range and high association degree, and plays an important role in the aspects of economic construction, social development, national defense construction and the like. In 2019, the yields of crude steel, pig iron and steel of industrial enterprises of which the scales are more than national scale are 99634 ten thousand tons, 80937 thousand tons and 120477 thousand tons respectively, and are increased by 8.3%, 5.3% and 9.8% respectively on the same scale, however, under the large background that the country greatly promotes ecological civilization construction, the green development becomes the main direction of future development of steel. The total amount of smoke dust (electric furnace steel-making dust, blast furnace gas dust and the like) generated in the steel smelting process exceeds 7000 million tons/year, and the smoke dust contains a large amount of valuable elements such as iron, zinc, lead and the like, if the elements can be separated and purified, the waste can be changed into valuable things, precious renewable resources can be obtained, the purpose of environmental management can be achieved, and the problem of resource shortage of iron ore and zinc ore in China can be solved, so that various steel enterprises and related research institutes are always researching and discussing the recycling of the smoke dust in the steel smelting for many years, but the process capable of effectively recycling the zinc element is not mature, and has a small difference from large-scale industrial recycling.
Iron and steel enterprises generally adopt the pyrometallurgical processes such as rotary kilns, rotary kilns and the like to carry out resource treatment on the smoke dust. The process utilizes the characteristic of low boiling point of zinc, lead and the like in the smoke dust to volatilize low boiling point components through a high-temperature reduction process in the kiln, thereby realizing the separation of various elements. However, research finds that the ring formation phenomenon in the kiln frequently occurs, and the ring formation phenomenon causes a series of problems of reduction of effective sectional area in the kiln, poor material flowability, increase of system resistance and the like, so that production line stop is caused, and resource recycling implementation of smoke dust in steel plants is seriously influenced. How to inhibit the ring formation phenomenon in a rotary kiln, improve the operation rate and realize continuous production becomes a difficult problem which is urgently desired to be solved by iron and steel enterprises, and the currently researched solutions are a mechanical method, a kiln washing method and an iron reduction method.
(1) Mechanical method: manufacturing a longer striker or mechanical arm, and once the wall sticking or ring forming phenomenon in the kiln is found, immediately carrying out mechanical impact treatment by using the striker until the ring forming object falls off; when the ring is serious, the kiln can be stopped, and then the ring is forcibly knocked off by using a manual or mechanical arm. The mechanical methods have great damage to refractory bricks in the kiln, and have great potential safety hazard, and the production efficiency is seriously influenced by the operation of stopping the kiln.
(2) A kiln washing method: when the accretion influences the normal flow of the material in the kiln, stopping feeding the smoke dust raw material, adjusting to conveying high-heat-value coke into the kiln, rapidly increasing the temperature in the kiln, softening the accretion at high temperature, separating from the kiln wall under the action of gravity, and flowing out along with the material. The method for cleaning the ring-forming materials wastes a large amount of coke resources, has great damage to a rotary kiln body, dust collection facilities and the like, and is still used in most factories.
(3) Iron reduction method: because the accretion contains low-melting-point compounds mainly containing iron, it is considered by some enterprises that a large amount of low-iron waste slag (e.g., electroplating sludge) should be added to the soot ash to reduce the iron content of the mixture to 20% or less when the mixture is put into a kiln. However, the operation reduces the magnetic separation value of the rotary kiln tailings, and simultaneously introduces new harmful elements such as sulfur, chlorine, arsenic and the like, and the tailings become secondary pollution wastes which are more difficult to treat because the harmful elements exceed the standard.
Patent No. CN110564969A discloses a method for comprehensively recovering lead, zinc and iron in blast furnace gas ash, and Na is used in the method2CO3And CaCO3The compounded roasting accelerant realizes the zinc volatilization rate of more than 95 percent and the lead volatilization rate of more than 86 percent and obtains iron ore concentrate with the grade of more than 65.00 percent, but does not solve the problem of substance deposition on the ring forming surface in the rotary kiln.
Patent No. CN103966421A discloses a comprehensive recycling method of ferrous metallurgy solid waste, the method comprises the steps of washing the solid waste, carrying out strong magnetic separation and weak magnetic separation on washing slag to obtain iron concentrate, roasting tailings after the magnetic separation and a reducing agent to obtain volatile Zn elements, and realizing the comprehensive utilization of the metallurgy solid waste. But the method has no large energy consumption, does not treat tail gas, and does not solve the problem of ring-forming sediment in the rotary kiln.
The invention has good advantages, but the problem that low-melting-point substances can be deposited on the surface of a ring in a rotary kiln is not solved, and the influences on the aspects of energy conservation, emission reduction and environmental protection are not researched and analyzed correspondingly. Because the rotary kiln is high in temperature, the low-melting-point compound can be attached to the inside of the rotary kiln in a liquid state, and the key content of the implementation method is how to inhibit the deposition of substances in the rotary kiln while ensuring the high element extraction rate.
Disclosure of Invention
The invention aims to provide a method for inhibiting ring formation in a kiln and improving the recovery rate of zinc, which overcomes the defects of the prior art, can improve the recovery rate of Zn and reduce the use of raw materials by adding a regulating material, can also improve the alkalinity of steel smelting smoke dust, increases the melting point of a mixed material, simultaneously regulates and controls a reaction competition mechanism formed by the material and other oxides in the steel smelting smoke dust, controls the generation of liquid-phase molten substances, reduces the adhesive capacity of the material and inhibits the ring formation problem; in addition, the regulated and controlled materials are finally mixed into the tailings of the rotary kiln to become important raw materials for preparing building materials, so that secondary pollution is avoided.
In order to achieve the purpose, the invention is realized by adopting the following technical scheme.
The method for inhibiting ring formation in a kiln and improving the recovery rate of zinc is characterized in that the steel smelting smoke dust with the total iron grade of more than or equal to 20 percent and the zinc grade of more than or equal to 20 percent adopts the following process steps to realize the zinc volatilization rate of more than 97 percent, obtain iron ore concentrate with the iron grade of more than 67 percent and simultaneously reduce the deposition of ring formation surface substances in a rotary kiln by 80 percent, and comprises the following specific steps:
1) mixing materials, namely adding coke accounting for 10-15% of the total mass of the iron and steel smelting dust ash into the zinc-containing iron and steel smelting dust ash, and adding a regulating material accounting for 10-15% of the total mass of the iron and steel smelting dust ash, wherein the regulating material is a uniform compound consisting of SiO2 and CaO, and the mass ratio of SiO2 to CaO is 3: 0.9-1.1;
2) charging, namely mixing the steel smelting smoke dust, the coke and the regulating material for 1-2 h by using a mixing stirrer, so that the steel smelting smoke dust, the coke and the regulating material are uniformly mixed;
3) roasting, namely loading the uniformly mixed materials into a rotary kiln with a flue gas recovery system for reduction roasting at 1150-1350 ℃ for 2-3 h;
4) drying, namely taking out the ring-forming sediment in the rotary kiln, and drying for 2-4 h at the drying temperature of 100-150 ℃;
5) water quenching, namely respectively performing water quenching on the roasted ore discharged in the step 3) and the ring-forming materials in the kiln, and cooling to normal temperature;
6) grinding and low-intensity magnetic separation recovery, wherein the material subjected to water quenching treatment is fed into a grinding and low-intensity magnetic separation recovery system, the grinding granularity interval is 88% -92%, and iron ore concentrate and tailings with iron grade of more than 67% are obtained after low-intensity magnetic separation;
and 3) actively extracting air in the reduction roasting process in the step 3), treating the extracted gas by a flue gas recovery system, collecting and obtaining a zinc element sludge product by the flue gas recovery system, and volatilizing more than 97% of zinc and then capturing and collecting.
The preferable mass ratio of SiO2 to CaO in the regulating material is 3: 1. The purity of the SiO2 is more than or equal to 96 percent. The purity of the CaO is more than or equal to 95 percent.
The pressure of the active air extraction is-0.2 to-0.8 atmospheric pressure.
The rotary kiln may be replaced with a reflection kiln or a tunnel kiln.
The low-intensity magnetic separation equipment is a wet permanent magnet drum magnetic separator, and the average magnetic induction intensity of the surface of the drum is 180-220 mT.
A cyclone dust collector and an electrostatic cloth bag dust collector are arranged in the flue gas recovery system.
The technical principle of the invention is as follows: regulating and controlling material adopts SiO2And CaO. The reaction principle of regulating and controlling CaO in the material is as follows:
the first step is as follows: ZnO + C = Zn + CO
The second step is that: ZnS + CaO + CO = Zn + CaS + CO2
The third step: CO 22+C=2CO
The fourth step: ZnO Fe2O3+CO=ZnO+2FeO+CO2
Zn exists in three forms in roasted ore, including ZnO, ZnS and ZnO-Fe2O3From the above chemical reactions, it is known that ZnO reacts with coke at a test temperature to generate Zn and CO, and the addition of CaO in the second step provides a reaction medium for the ZnS reduction reaction, so that CO generated in the first step is utilized, and ZnS is reduced to Zn while avoiding environmental pollution caused by CO, and is recovered. Third step CO is produced by coke in a rotary furnace2The generated CO is ZnS in the second step and ZnO & Fe in the fourth step2O3The generated ZnO continues to carry out the first-step reduction reaction with the coke, and CO are recycled in the whole reaction process2Not only reduces the use of raw materials, but also avoids the pollution to the environment caused by excessive CO. In addition, SiO in novel control materials2Increase Zn2Al4Si5O18, Mg2Al4Si5O18When the melting point of the low-melting-point compound in the rotary kiln is equal, and the temperature in the rotary kiln is 1150-1350 ℃, the phenomenon that the low-melting-point compound forms a liquid phase and then causes wall hanging can be avoided, so that SiO2The addition of the (A) effectively inhibits the ring formation phenomenon in the kiln.
Research shows that the method of the invention adopts the method of adding a novel regulating material SiO into the dust ash of the iron and steel smelting2And CaO is used for promoting the high-efficiency volatilization of Zn in the roasting process of the rotary furnace, the method can realize the high Zn element recovery rate at a lower temperature, realize the reduction reaction of different Zn compounds, and reduce the use of reaction raw materials and the emission of harmful gases. In addition, the addition of the novel regulating material improves the melting point of the low-melting-point compound, inhibits the ring formation phenomenon in a kiln, improves the economic benefit of a factory, increases the comprehensive treatment capacity of the smoke dust of the iron and steel plant, and improves the production utilization rate.
Compared with the prior art, the invention has the beneficial effects that:
1) the invention adopts the novel additionRegulating and controlling material SiO2And CaO, the higher Zn recovery rate can be realized, and the zinc-containing sludge product can be independently separated, enriched and prepared into zinc oxide and other products, and can also be directly sold to smelting manufacturers of related products, so that the comprehensive treatment capacity of the smoke dust of the steel plant is improved, and the production profit rate is improved;
2) the invention adopts the addition of a novel regulating material SiO2And CaO, higher Zn volatilization rate can be obtained at lower roasting temperature and shorter roasting time, and compared with the traditional process, the method reduces energy consumption and improves roasting efficiency;
3) the invention adopts the addition of a novel regulating material SiO2And CaO, the gas can be recycled, the use of coke is reduced, and the emission of harmful gas is reduced while the material cost is saved compared with the traditional process;
4) the addition of novel regulating materials SiO2 and CaO can improve the alkalinity of the dust of the steel smelting smoke dust, increase the melting point of the mixed materials, simultaneously regulate and control the reaction competition mechanism formed by the materials and other oxides in the dust of the steel smelting smoke dust, control the generation of liquid-phase melt, reduce the adhesive capacity of the materials, reduce the weight of the dried inner ring-forming sediment by 80 percent compared with the inner ring-forming surface sediment of the rotary kiln without the regulating materials, and obviously inhibit the ring-forming phenomenon;
5) according to the invention, the novel regulating materials SiO2 and CaO are added, the recovery rate of the iron ore concentrate reaches 80-90%, and in addition, the regulating materials are finally mixed into the tailings of the rotary kiln, so that the method can be used for preparing building materials, and secondary pollution is avoided.
Drawings
FIG. 1 is a process flow diagram of an embodiment of the present invention.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention.
To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will briefly explain the embodiments. Thus, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention.
The raw material of the steel smelting dust used in the examples was a mixed sample of the steel smelting dust collected from Panzhihua group, and the results of the multi-element analysis of the steel smelting dust were shown in Table 1. The substances for comparison in this example were samples of substances collected from Hongyan rock science and technology Limited, Panzhihua, and the substances were analyzed for multiple elements, the results of which are shown in Table 2.
TABLE 1 analysis results of Multi-elements in raw materials for dust and ash of iron and steel smelting (%)
The results of the multi-element analysis show that the iron and steel smelting dust contains 22.35% of total iron, 26.68% of carbon and 23.34% of zinc.
TABLE 2 Multi-element analysis results (%) -of the substances forming the rings in the rotary kiln for comparison
| Element(s) | C | O | Al | Si | Ca | Mg | Fe | Zn | S |
| Content (wt.) | 5.79 | 31.09 | 7.88 | 12.49 | 14.50 | 1.31 | 23.45 | 0.57 | 0.76 |
The results of the multi-element analysis show that the ring formation material in the rotary kiln comprises Zn2Al4Si5O18, Mg2Al4Si5O18Composition and containing a large amount of Fe3O4。
FIG. 1 is a process flow chart of the method for inhibiting ring formation in a kiln and improving the recovery rate of zinc, and comprehensive recovery research is carried out on the dust of the iron and steel smelting under laboratory conditions. A pilot line rotary kiln adopted in a laboratory is 50m long and 1.2m in inner diameter, is lined with 50 mm-thick refractory materials, and is embedded with 8 thermocouples along the length direction of the rotary kiln to realize continuous temperature measurement. Adding the material from the tail of the kiln, discharging the roasted material from the head of the kiln, and falling into a water quenching pool; the kiln head is provided with a burner, the filling liquefied gas is used as fuel, the burner and the negative pressure in the kiln are adjustable, the inclination angle of the rotary kiln body is 1-8 degrees, and the rotating speed is 0-20 r/min.
For example, when the rotary kiln is used in large-scale production, the rotary kiln can be replaced by a reflection kiln or a tunnel kiln. A cyclone dust collector and an electrostatic cloth bag dust collector can be arranged in the flue gas recovery system, so that zinc sediment sludge and fly ash with different specific gravities can be better separated.
The method for inhibiting ring formation in a kiln and improving the recovery rate of zinc comprises the following specific steps:
1) mixing materials, namely adding coke accounting for 12-14% of the total mass of the iron and steel smelting dust ash into the iron and steel smelting dust ash, and adding a regulating material accounting for 12-13% of the total mass of the iron and steel smelting dust ash, wherein the regulating material is a uniform compound consisting of SiO2 and CaO, and the mass ratio of SiO2 to CaO is 3: 1; the purity of SiO2 is more than or equal to 96 percent, and the purity of CaO is more than or equal to 95 percent;
2) charging, namely mixing the iron and steel smelting smoke dust, coke and a regulation and control material for 1.5 hours by using a mixing stirrer, uniformly mixing the iron and steel smelting smoke dust, the coke and the regulation and control material, pouring the mixed material into a self-made roasting container, shaking the charged roasting container to make the material layer height uniform, stopping charging and shaking when the material layer thickness reaches 35mm, and then uniformly covering the surface of a leveling material layer with a proper amount of coke;
3) roasting, namely loading the uniformly mixed materials into a rotary kiln with a flue gas recovery system for reduction roasting, roasting at constant temperature, wherein the roasting temperature is 1200 ℃, when the roasting time reaches 2.2 hours, the power is cut off and the temperature is reduced, the mixed materials are naturally cooled along with the furnace, active air extraction is carried out every 10min in the roasting process and the cooling process, when the furnace temperature is reduced to be below 900 ℃, the roasting container is removed, more than 97% of zinc is volatilized and then captured and collected, and the flue gas recovery system collects a sludge product of zinc element. And depositing, filtering and drying Zn collected in the flue gas recovery system for subsequent preparation of the Zn oxide. The air exhaust pressure of an air exhauster of a flue gas recovery system adopted in a laboratory is-0.2 to-0.8 atmospheric pressure;
4) drying, namely taking out the ring-forming sediment in the rotary kiln, and drying for 2.5h at the drying temperature of 130-140 ℃, and performing element detection on the ring-forming sediment in the rotary kiln sampled in the embodiment, wherein the element detection result is shown in table 3;
5) water quenching, namely respectively performing water quenching on the roasted ore discharged in the step 3) and the ring-forming materials in the kiln, wherein the temperature before water quenching is not lower than 850 ℃, and cooling to below 50 ℃ after water quenching;
6) grinding and low-intensity magnetic separation recovery, wherein the material subjected to water quenching treatment is fed into a grinding and low-intensity magnetic separation recovery system, the grinding granularity interval is 90%, and iron ore concentrate and tailings with the iron grade of more than 67% are obtained after low-intensity magnetic separation; the low-intensity magnetic separation equipment is a wet permanent magnet drum magnetic separator, the average magnetic induction intensity of the surface of the drum is 200mT, and iron ore concentrate with the total iron grade of more than 67% can be obtained.
And (3) placing the roasting container taken out in the step 6) in a high-temperature box for drying, weighing after the moisture in the roasting container is completely volatilized, sampling and detecting the content of Zn element in the roasting container, wherein the grade of the obtained zinc is 0.58%, and the zinc volatilization rate reaches 97.42% through conversion.
Table 3 analysis results of multielement analysis of ring-forming material in rotary kiln (%)
As can be seen from Table 3, the content of low-melting-point compounds (such as Al, Si, Ca and the like) in the substances on the surface of the ring formation in the rotary furnace can be effectively reduced by regulating and controlling the addition of the materials, the frequent cleaning of the surface of the ring formation in the rotary furnace is avoided, the economic benefit of a steel plant can be effectively improved, the addition of the materials can effectively promote the volatilization of Zn elements, various Zn compounds are subjected to sufficient reduction reaction, the consumption of raw materials is reduced, and the content of harmful gases discharged to the environment can be also reduced substantially.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore intended that all such changes and modifications as fall within the true spirit and scope of the invention be considered as within the following claims.
Claims (8)
1. The method for inhibiting ring formation in a kiln and improving the recovery rate of zinc is characterized in that the steel smelting smoke dust with the total iron grade of more than or equal to 20 percent and the zinc grade of more than or equal to 20 percent adopts the following process steps to realize the zinc volatilization rate of more than 97 percent, obtain iron ore concentrate with the iron grade of more than 67 percent and simultaneously reduce the deposition of ring formation surface substances in a rotary kiln by 80 percent, and comprises the following specific steps:
mixing materials, namely adding coke accounting for 10-15% of the total mass of the zinc-containing steel smelting dust ash into the zinc-containing steel smelting dust ash, and adding a regulating material accounting for 10-15% of the total mass of the steel smelting dust ash, wherein the regulating material is SiO2With CaO, SiO2The mass ratio of the CaO to the CaO is 3: 0.9-1.1;
charging, namely mixing the steel smelting smoke dust, the coke and the regulating material for 1-2 h by using a mixing stirrer, so that the steel smelting smoke dust, the coke and the regulating material are uniformly mixed;
roasting, namely loading the uniformly mixed materials into a rotary kiln with a flue gas recovery system for reduction roasting at 1150-1350 ℃ for 2-3 h;
drying, namely taking out the ring-forming sediment in the rotary kiln, and drying for 2-4 h at the drying temperature of 100-150 ℃;
water quenching, namely respectively performing water quenching on the roasted ore discharged in the step 3) and the ring-forming materials in the kiln, and cooling to normal temperature;
grinding and low-intensity magnetic separation recovery, wherein the material subjected to water quenching treatment is fed into a grinding and low-intensity magnetic separation recovery system, the grinding granularity interval is 88% -92%, and iron ore concentrate and tailings with iron grade of more than 67% are obtained after low-intensity magnetic separation;
and 3) actively extracting air in the reduction roasting process in the step 3), treating the extracted gas by a flue gas recovery system, collecting and obtaining a zinc element sludge product by the flue gas recovery system, and volatilizing more than 97% of zinc and then capturing and collecting.
2. The method for inhibiting ring formation in a kiln and improving the recovery rate of zinc as claimed in claim 1, wherein the SiO in the material is regulated and controlled2The preferred mass ratio to CaO is 3: 1.
3. The method of claim 1 for inhibiting ring formation in kiln and improving zinc recoveryThe method of yield is characterized in that the SiO2The purity of the product is more than or equal to 96 percent.
4. The method for inhibiting ring formation in a kiln and improving the recovery rate of zinc as claimed in claim 1, wherein the purity of CaO is greater than or equal to 95%.
5. The method for inhibiting ring formation in a kiln and improving the recovery rate of zinc as claimed in claim 1, wherein the pressure of the active air extraction is-0.2 to-0.8 atm.
6. The method for inhibiting ring formation in a kiln and improving the recovery rate of zinc as claimed in claim 1, wherein the rotary kiln can be replaced by a reflection kiln or a tunnel kiln.
7. The method for inhibiting the ring formation in the kiln and improving the recovery rate of zinc as claimed in claim 1, wherein the low-intensity magnetic separation equipment is a wet permanent magnet drum magnetic separator, and the average magnetic induction intensity on the surface of the drum is 180-220 mT.
8. The method for inhibiting ring formation in a kiln and improving the recovery rate of zinc according to claim 1, wherein a cyclone dust collector and an electrostatic bag dust collector are arranged in the flue gas recovery system.
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