CN114887759A - Method for separating iron powder from Bayer process red mud - Google Patents
Method for separating iron powder from Bayer process red mud Download PDFInfo
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- CN114887759A CN114887759A CN202210339464.XA CN202210339464A CN114887759A CN 114887759 A CN114887759 A CN 114887759A CN 202210339464 A CN202210339464 A CN 202210339464A CN 114887759 A CN114887759 A CN 114887759A
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C1/00—Magnetic separation
- B03C1/005—Pretreatment specially adapted for magnetic separation
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C1/00—Magnetic separation
- B03C1/005—Pretreatment specially adapted for magnetic separation
- B03C1/01—Pretreatment specially adapted for magnetic separation by addition of magnetic adjuvants
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C1/00—Magnetic separation
- B03C1/02—Magnetic separation acting directly on the substance being separated
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Abstract
The invention particularly relates to a method for sorting iron powder by Bayer process red mud, which belongs to the technical field of resource recovery and comprises the following steps: mixing the red mud and the dealkalization auxiliary agent to obtain mixed slurry; dealkalizing the mixed slurry, and then filtering and washing to obtain filtrate, washing liquid and a filter cake; carrying out secondary pulping on the filter cake and the first magnetic separation tailing filtrate to obtain filter cake slurry; carrying out seed crystal magnetization on the filter cake slurry, and then carrying out magnetic separation to obtain an iron powder product and a second magnetic separation tailing filtrate; recycling the second magnetic separation tailing filtrate to secondary pulping; the iron powder is recovered by the combined production of red mud dealkalization and magnetic separation, the monomer dissociation degree of hematite is improved after the red mud dealkalization, the recovery rate of the red mud iron powder is further improved, the alkali recovery is realized, and the technical economy is greatly improved.
Description
Technical Field
The invention belongs to the technical field of resource recovery, and particularly relates to a method for separating iron powder from Bayer process red mud.
Background
Red mud, a waste produced in the process of refining alumina from bauxite, is known as red-red mud slurry. With the continuous development of the bauxite industry, the red mud discharge amount of China is more than 1500 million tons every year, and the total mass of the red mud tends to increase with the new production and the yield increase transformation of old equipment. Most alumina factories around the world pile or dump red mud into deep sea, the storage of the red mud not only occupies a large amount of land and farmland and consumes more construction and maintenance cost of a storage yard, but also residual alkaline liquor in the red mud can permeate underground to cause groundwater pollution. In addition, dust formed by red mud in a yard flies everywhere, so that the ecological environment is damaged, and serious pollution is caused. In the current society where land resources are increasingly tense and environmental protection is increasingly important, comprehensive treatment of red mud has become one of the focuses of people. The red mud is the largest waste generated in the production process of the alumina and also the largest pollution source in the production of the alumina. Due to the difference between the production method and the bauxite grade, about 0.5 to 2.5 tons of red mud are generated for each ton of alumina, and 3 to 4m is additionally added for each ton of red mud 3 The alkali-containing waste liquid.
The red mud can be divided into three types of red mud, namely sintering process, Bayer process and combination process, according to different alumina production methods, and the alumina production methods adopted at home and abroad are different due to different bauxite content abundance. Except China and the Soviet Union, other countries adopt Bayer process production, and the yield of the Bayer process accounts for more than 90 percent of the total world yield. The Bayer process adopts strong base NaOH to dissolve out high-alumina and high-iron bauxite, the red mud produced has high alumina, iron oxide and alkali content, and the processed bauxite is boehmite type and gibbsite type. The sintering method and the combined method are used for treating indissolvable bauxite with high silicon content, low iron content, diaspore type bauxite and kaolinite type bauxite, and the red mud Ca0 generated by the method is high in content and low in alkali and iron content. The red mud is prepared by sintering process and combination process for producing alumina from diasporic bauxite, and the main components are dicalcium silicate and hydrate thereof; the Bayer process is mainly used abroad, and the main components of the Bayer process red mud are hematite, sodium aluminosilicate hydrate, cancrinite and the like.
At present, because hematite is wrapped by sodium-silicon slag under many conditions, the monomer dissociation degree is very low, and good separation can not be obtained during magnetic separation, so that the yield of iron powder is always low, and the economic deviation of the iron separation technology is caused.
Disclosure of Invention
The application aims to provide a method for separating iron powder from Bayer process red mud, which aims to solve the problem of low yield of iron powder caused by low dissociation degree of hematite monomers at present.
The embodiment of the invention provides a method for sorting iron powder by Bayer process red mud, which comprises the following steps:
mixing the red mud and the dealkalization auxiliary agent to obtain mixed slurry;
dealkalizing the mixed slurry, and then filtering and washing to obtain filtrate, washing liquid and a filter cake;
carrying out secondary pulping on the filter cake and the first magnetic separation tailing filtrate to obtain filter cake slurry;
carrying out seed crystal magnetization on the filter cake slurry, and then carrying out magnetic separation to obtain an iron powder product and a second magnetic separation tailing filtrate;
and recycling the second magnetic separation tailing filtrate to secondary pulping.
Optionally, the dealkalization auxiliary agent comprises at least one of calcium hydroxide and carbide slag, and the red mud is final secondary bayer process red mud.
Optionally, in the mixed slurry, the mass concentration of the dealkalization auxiliary agent is 100g/L-500g/L, and the mass concentration of the red mud is 200g/L-550 g/L.
Optionally, the relationship between the content [ Ca ] of the amount of Ca substance in the dealkalization assistant and the content [ Na ] of the amount of Na substance in the mixed slurry satisfies: [ Ca ]: Na ] ═ 1-5: 1.
Optionally, the temperature of the dealkalization treatment is 90-100 ℃, and the dealkalization treatment time is 0.5-4 h.
Optionally, in the filter cake slurry, the mass concentration of the filter cake is 50g/L-300 g/L.
Optionally, the seed crystal magnetized by the seed crystal is Fe 3 O 4 The grain size D50 of the seed crystal is 1-10 μm.
Optionally, in the seed crystal magnetization, the added mass of the seed crystal accounts for 0.1-1% of the mass of the filter cake.
Optionally, the magnetic field intensity of the magnetic separation is 8000GS-14000 GS.
Optionally, the method further includes: and recovering the filtrate and the washing liquid to obtain recovered alkali.
One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:
according to the method for separating iron powder from red mud by the Bayer process, the iron powder is recovered by dealkalization and magnetic separation for coproduction, the monomer dissociation degree of hematite is improved after the dealkalization of the red mud, the recovery rate of the iron powder from the red mud is further improved, the recovery of alkali is realized, and the technical economy is greatly improved.
The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.
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In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.
Fig. 1 is a flow chart of a method provided by an embodiment of the invention.
Detailed Description
The present invention will be described in detail below with reference to specific embodiments and examples, and the advantages and various effects of the present invention will be more clearly apparent therefrom. It will be understood by those skilled in the art that these specific embodiments and examples are for the purpose of illustrating the invention and are not to be construed as limiting the invention.
Throughout the specification, unless otherwise specifically noted, terms used herein should be understood as having meanings as commonly used in the art. Accordingly, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. If there is a conflict, the present specification will control.
Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.
In order to solve the technical problems, the general idea of the embodiment of the application is as follows:
the applicant finds in the course of the invention that: in the recovery of metallic iron from red mud, a lot of studies have been made in soviet union, japan, usa, germany, etc., and although the time of foreign studies is relatively early, most of them are 60 to 80 years, there are still not many practical applications. In China, the plane bauxite contains various valuable metals, the plane bauxite industry company and Guangxi metallurgical research institute jointly make a test research of direct reduction ironmaking by taking the Bayer process red mud of plane bauxite as a raw material and coal as a reducing agent, and the process flow comprises the steps of mixing the red mud and the coal, briquetting, drying, then carrying out reduction roasting, and finally carrying out magnetic separation to prepare sponge iron.
At present, Ganxzhou color research institute and other companies adopt a high-gradient and high-strength magnetic separator to recover iron in red mud, quartz is not obtained, and meanwhile, the investment and operation cost is high and the recovery rate is low.
The methods of lime dealkalization and salt dealkalization are two methods which are most likely to realize industrialization in the future. The lime is cheap, and a good dealkalization effect can be obtained by controlling influence factors; the effect of salt dealkalization is very obvious, and a plurality of industrial waste salts can be utilized. In addition, if lime dealkalization and salt dealkalization are combined and a suitable salt (most likely, a magnesium-containing salt) is selected, it is possible to achieve a better dealkalization effect for red mud.
Dealkalized red mud is well applied, and the dealkalization economy of red mud is poor due to the angle of only recovering alkali, so that the industrialization is not really realized.
The key technology for efficiently selecting iron from red mud comprises three parts, namely high-efficiency process, high-efficiency process and high-efficiency equipment, wherein the red mud sedimentation section in the alumina process is tightly grafted and combined, and the red mud is directly subjected to in-situ separation, so that multiple technologies such as heavy-magnetic combination, unidirectional gradient, multidirectional gradient, electromagnetic vertical ring and permanent magnet high-magnetism combined multi-stage separation, medicament flocculation magnetization and the like are developed, and the yield, grade and recovery rate of iron powder separated from the red mud can reach higher levels. At present, the technology forms three sets of key technical systems of red mud micro-fine particle separation, fine separation and low-cost separation, and is respectively applied to separation of foreign high-iron Bayer process red mud, domestic high-temperature low-iron Bayer process red mud, domestic high-iron Bayer process red mud and foreign difficult-to-beneficiate red mud. The technical system is industrialized on Shandong aluminum and Huaxing aluminum, the capacity of producing 20 million tons of iron powder every year is formed, remarkable economic benefit is obtained, and the emission reduction of the red mud is realized by 20% every year.
However, hematite is wrapped by sodium-silicon slag under many conditions, so that the monomer dissociation degree is very low, and the iron powder cannot be well separated during magnetic separation, so that the yield of the iron powder is always low, and the economical efficiency of the iron separation technology is deviated.
Aiming at the current situation of red mud stockpiling and the current situation of a production process for dealkalizing red mud, the method for dealkalizing red mud and coproducing iron fine powder by the Bayer process is provided, the dissociation degree of hematite is improved during dealkalization, more iron fine powder is obtained after separation, and the economic benefit of red mud utilization is improved.
According to an exemplary embodiment of the present invention, there is provided a method for sorting iron powder from bayer process red mud, the method comprising:
s1, mixing red mud and a dealkalization auxiliary agent to obtain mixed slurry;
in some embodiments, the red mud is selected from green bayer process red mud.
The final secondary red mud is adopted for dealkalization, the alumina process balance is not influenced, and the dealkalization efficiency and economy of the red mud can be improved.
In some embodiments, the dealkalization aid is selected from one of calcium hydroxide and carbide slag.
In some embodiments, the dealkalization auxiliary agent has a mass concentration of 100g/L to 500g/L, and the red mud has a mass concentration of 200g/L to 550 g/L.
The reason for controlling the mass concentration of the dealkalization auxiliary agent to be 100g/L-500g/L is that the effective components in the dealkalization auxiliary agent are preferentially mixed with Al in the red mud slurry 3+ Reaction, consuming a certain amount of Ca 2+ Then, the sodium aluminosilicate hydrate undergoes an ionic reaction, so that under the condition that the reaction tends to be balanced, the mass concentration interval is controlled, the excessive concentration value leads to the excessive residual quantity of the auxiliary agent, and further leads to the reduction of the product purity, and then the resource waste is caused, the production cost is increased, and the insufficient dealkalization degree is caused by the too small concentration, so that the dealkalization effect is poor.
The concentration of the red mud is controlled to be 200g/L-550g/L, tests prove that the slurry viscosity and density in the concentration range are moderate, the flow resistance is small, the subsequent filter pressing performance is facilitated, the surface tension and the liquid viscosity of a slurry system are increased when the concentration is excessively high, the dynamic difficulty of dealkalization reaction is increased, the dealkalization effect is poor, and the dealkalization efficiency is low due to excessively low concentration.
In some embodiments, the relationship of the content of the amount of the substance of Ca [ Ca ] in the dealkalization assistant to the content of the amount of the substance of Na [ Na ] in the mixed slurry satisfies: [ Ca ] - [ Na ] - [ 1-5: 1.
The reason for controlling the ratio of [ Ca ] to [ Na ] to 1-5:1 is based on the chemical reaction equilibrium proportion of Ca in the dealkalization auxiliary agent and the total amount of free state Na and combined state Na in the Bayer process red mud slurry, the adverse effect of the overlarge ratio is that dealkalization is excessive, the excessive residual Ca affects the product purity, and the adverse effect of the undersize is that the dealkalization degree is insufficient, so that the dealkalization effect is poor. Preferably, the relationship between the content [ Ca ] of the amount of Ca substance in the dealkalization assistant and the content [ Na ] of the amount of Na substance in the mixed slurry satisfies: [ Ca ]: 2-4: 1.
s2, dealkalizing the mixed slurry, and then filtering and washing to obtain filtrate, washing liquid and a filter cake;
in some embodiments, the temperature of the dealkalization treatment is from 90 ℃ to 100 ℃ and the dealkalization treatment time is from 0.5h to 4 h.
The reason that the temperature of dealkalization treatment is controlled to be 90-100 ℃ and the time is controlled to be 0.5-4 h is that the ion exchange rate under the condition is high and is beneficial to Ca 2+ The dealkalization effect is enhanced by fully contacting with the hydrated sodium aluminosilicate, the adverse effect of overlarge value is that the free energy in the dealkalization reaction process is increased, the dealkalization reaction is adverse, energy waste is caused, and the adverse effect of undersize is that the kinetic and thermodynamic conditions of the chemical reaction are not sufficiently reached, so that the dealkalization degree is insufficient.
S3, carrying out secondary pulping on the filter cake and the first magnetic separation tailing filtrate to obtain filter cake slurry;
in some embodiments, the mass concentration of the filter cake in the filter cake slurry is from 50g/L to 300 g/L.
The reason for controlling the mass concentration of the filter cake to be 50g/L-300g/L is that the collision probability between the hematites in the concentration interval range is higher, so that the magnetization reaction is favorably carried out, although the collision probability between the hematites is increased due to overlarge concentration value, the collision probability between the hematites and other gangue minerals is also increased, the magnetization effect of the hematites is not obviously improved, and the undersize adverse effect is that the magnetization efficiency of the hematites is not high. Preferably, the mass concentration of the filter cake is 100g/L-230 g/L.
S4, carrying out seed crystal magnetization on the filter cake slurry, and then carrying out magnetic separation to obtain an iron powder product and a second magnetic separation tailing filtrate;
at one endIn some embodiments, the seed magnetized by the seed may be selected from Fe 3 O 4 The grain size D50 of the seed crystal is 1-10 μm.
The reason for controlling the grain size D50 of the seed crystal to be 1-10 mu m is that the specific surface area of the seed crystal under the grain size condition is larger, which is beneficial to strengthening the mass transfer function between the slurry and the seed crystal, destroying the wrapping layer of the sodium-silicon slag on the hematite and being beneficial to the magnetization reaction, the adverse effect of overlarge grain size is that the interface energy of the magnetization reaction is insufficient, the active points on the surface of the wrapping layer can not be fully utilized, and the adverse effect of undersize is that the production cost is increased. Preferably, the seed crystal has a particle size D50 of 1 μm to 5 μm.
In some embodiments, the added mass of seed crystals in the magnetization of the seed crystals is between 0.1% and 1% of the mass of the filter cake.
Based on the optimal synergistic reaction ratio of the seed crystal and the filter cake, the addition mass of the seed crystal is controlled to be 0.1-1% of the mass of the filter cake, and the mass ratio interval is enough from the production cost perspective, the adverse effect of overlarge ratio value is to increase the production cost, the improvement degree of the magnetization effect of the seed crystal is not obvious, the adverse effect of undersize is to ensure that the form conversion degree of Fe is insufficient, and the magnetization effect of the seed crystal is not good. Preferably, the added mass of the seed crystal accounts for 0.1-0.5% of the mass of the filter cake.
In some embodiments, the magnetic field strength for the magnetic separation is 8000GS-14000 GS. Preferably, the magnetic field intensity of the magnetic separation is 9000GS-12000 GS.
S5, recycling the second magnetic separation tailing filtrate to secondary pulping;
s6, recovering the filtrate and the washing liquid to obtain recovered alkali.
In actual practice, the steps include:
(1) dealkalizing the red mud and dealkalizing assistant in the final secondary Bayer process by controlling certain process conditions, filtering and washing slurry; the filtrate and washing liquid are returned to an alumina plant to recover alkali.
(2) Adding the filter cake into the magnetic separation tailing filtrate for secondary pulping, adding seed crystals into the secondary slurry to enter a magnetic separation system, magnetizing the seed crystals, controlling certain conditions for magnetic separation, performing filter pressing on the magnetic separation concentrate to obtain iron powder, performing filter pressing on the magnetic separation tailing to obtain tailing, returning the filtrate to the dealkalized filter cake for pulping, and stacking the tailing.
The method for sorting iron powder by bayer process red mud according to the present application will be described in detail below with reference to examples, comparative examples and experimental data.
Example 1:
a method for sorting iron powder by Bayer process red mud comprises the following steps:
1000ml of red mud obtained by the last secondary Bayer process is taken, and the concentration is 500 g/l. According to [ Ca ]/[ Na ] ═ 3: 1. the dealkalization auxiliary agent is added and consists of calcium hydroxide and carbide slag, and the concentration is controlled to be 150 g/l. Controlling the dealkalization temperature to be 98 ℃ and the dealkalization time to be 1 hour.
Filtering and washing, returning the filtrate to an alumina plant, adding the filter cake into secondary tailing filtrate for secondary pulping, controlling the concentration to be 220g/l, and adding Fe with d50 being 8um 3 O 4 Seed crystal 20g, controlling magnetic field intensity 11000gs, filter-pressing magnetic concentrate to obtain iron powder 170 g, filter-pressing magnetic tailings to obtain tailings 350 g, and piling up. Returning the filtrate to be pulped with dealkalized filter cake.
Example 2:
a method for sorting iron powder by Bayer process red mud comprises the following steps:
1000ml of red mud obtained by the last secondary Bayer process is taken, and the concentration is 400 g/l. According to [ Ca ]/[ Na ] ═ 5: 1. calcium hydroxide was added to the solution to control the concentration of calcium hydroxide to 400 g/l. Controlling the dealkalization temperature at 90 ℃ and the dealkalization time for 2 hours.
Filtering and washing, returning the filtrate to an alumina plant, adding the filter cake into secondary tailing filtrate for secondary pulping, controlling the concentration to be 100g/l, and adding Fe with d50 being 2um 3 O 4 5 g of seed crystal, 9000gs of magnetic field intensity, 65 g of iron powder obtained by filter pressing of magnetic concentrate and 140 g of tailings obtained by filter pressing of magnetic tailings. Returning the filtrate to be pulped with dealkalized filter cake.
Comparative example 1:
a method for sorting iron powder by Bayer process red mud comprises the following steps:
taking 1000ml of red mud obtained by a secondary Bayer process, directly filtering and washing, returning filtrate to an alumina plant, adding filter cake into secondary tailing filtrate for secondary pulping, controlling the concentration to be 220g/l, and adding Fe with d50 being 8 mu m 3 O 4 Seed crystal 20g, magnetic field intensity controlled 11000gs, magnetic separation concentrate filter pressing to obtain iron powder 120 g, magnetic separation tailings filter pressing to obtain tailings 400g, and stockpiling. Returning the filtrate to be pulped with dealkalized filter cake.
Comparative example 2:
a method for sorting iron powder by Bayer process red mud comprises the following steps:
1000ml of red mud obtained by the last secondary Bayer process is taken, and the concentration is 400 g/l. According to [ Ca ]/[ Na ] ═ 6: 1. calcium hydroxide was added to the solution to control the concentration of calcium hydroxide to 450 g/l. Controlling the dealkalization temperature at 90 ℃ and the dealkalization time for 2 hours.
Filtering and washing, returning the filtrate to an alumina plant, adding the filter cake into secondary tailing filtrate for secondary pulping, controlling the concentration to be 100g/l, and adding Fe with d50 being 2um 3 O 4 5 g of seed crystal, 9000gs of magnetic field intensity, 70 g of iron powder obtained by filter pressing of magnetic concentrate, and 155 g of tailings obtained by filter pressing of magnetic tailings. Returning the filtrate to be pulped with dealkalized filter cake.
The treatment cases of examples 1-2 and comparative examples 1-2 are shown in the following table:
| the weight/g of iron powder is obtained | Obtaining the weight of the tailings per gram | |
| Example 1 | 170 | 350 |
| Example 2 | 65 | 140 |
| Comparative example 1 | 120 | 400 |
| Comparative example 2 | 70 | 135 |
From the above table, the yield of iron powder is high when the method provided by the examples of the present application is used for sorting the red mud, and the yield of iron powder is only 23% when the processes of dealkalization and magnetic separation are not used for matching, as can be obtained by comparing the comparative example 1 and the example 1. As can be seen from comparison of comparative example 2 and example 2, when the concentration of calcium hydroxide is increased by 12.5% in [ Ca ]/[ Na ] >5, the yield of iron powder is increased by only 7.6%.
One or more technical solutions in the embodiments of the present invention at least have the following technical effects or advantages:
(1) according to the method provided by the embodiment of the invention, iron powder is recovered through red mud dealkalization and magnetic separation to co-produce iron fine powder, the dissociation degree of hematite is improved while dealkalization is carried out, more iron fine powder is obtained after separation, and the economic benefit of red mud utilization is improved.
Finally, it should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (10)
1. A method for sorting iron powder by Bayer process red mud is characterized by comprising the following steps:
mixing the red mud and the dealkalization auxiliary agent to obtain mixed slurry;
dealkalizing the mixed slurry, and then filtering and washing to obtain filtrate, washing liquid and a filter cake;
carrying out secondary pulping on the filter cake and the first magnetic separation tailing filtrate to obtain filter cake slurry;
carrying out seed crystal magnetization on the filter cake slurry, and then carrying out magnetic separation to obtain an iron powder product and a second magnetic separation tailing filtrate;
and recycling the second magnetic separation tailing filtrate to secondary pulping.
2. The method for separating iron powder from Bayer process red mud according to claim 1, wherein the dealkalization assistant comprises at least one of calcium hydroxide and carbide slag, and the red mud is final secondary Bayer process red mud.
3. The method for sorting iron powder from Bayer process red mud according to claim 1, wherein the mass concentration of the dealkalization auxiliary agent in the mixed slurry is 100g/L-500g/L, and the mass concentration of the red mud is 200g/L-550 g/L.
4. The method for sorting iron powder from bayer process red mud according to claim 3, wherein the relationship between the content [ Ca ] of the amount of Ca substance in the dealkalization aid and the content [ Na ] of the amount of Na substance in the mixed slurry satisfies: [ Ca ]: Na ] ═ 1-5: 1.
5. The method for sorting iron powder from bayer process red mud according to claim 1, wherein the temperature of the dealkalization treatment is 90 ℃ to 100 ℃, and the dealkalization treatment time is 0.5h to 4 h.
6. The method for sorting iron powder from bayer process red mud of claim 1, wherein the mass concentration of the filter cake in the filter cake slurry is 50g/L to 300 g/L.
7. The method for sorting iron powder from bayer process red mud according to claim 1, wherein the seed crystal magnetized by the seed crystal is Fe 3 O 4 The grain size D50 of the seed crystal is 1-10 μm.
8. The method for sorting iron powder from bayer process red mud according to claim 1, wherein the added mass of the seed crystals in the magnetization of the seed crystals accounts for 0.1-1% of the mass of the filter cake.
9. The method for separating iron powder from Bayer process red mud according to claim 1, wherein the magnetic field strength for the magnetic separation is 8000GS-14000 GS.
10. The method for the sorting of iron powder from bayer process red mud according to claim 1, further comprising: and recovering the filtrate and the washing liquid to obtain recovered alkali.
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Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1334320A (en) * | 1961-10-30 | 1963-08-09 | Improvements in the processing of ores containing a magnetic or magnetizable element, and products thus obtained | |
| CN1613809A (en) * | 2004-11-25 | 2005-05-11 | 中国铝业股份有限公司 | Method for producing cement from red mud |
| CN1743472A (en) * | 2005-09-22 | 2006-03-08 | 贵阳铝镁设计研究院 | Method for recovering iron from red mud |
| CN101417261A (en) * | 2008-11-21 | 2009-04-29 | 中国铝业股份有限公司 | Bayer process red mud processing method |
| CN101912814A (en) * | 2010-08-09 | 2010-12-15 | 中国铝业股份有限公司 | Method for magnetic separation of iron ore concentrate in red mud slurry in alumina production flow by Bayer process |
| CN103898330A (en) * | 2014-03-28 | 2014-07-02 | 中国铝业股份有限公司 | Method for comprehensively recycling such valuable metals as iron, aluminum, scandium, titanium, vanadium and the like in red mud |
| CN104368440A (en) * | 2014-09-30 | 2015-02-25 | 中国铝业股份有限公司 | Novel technology and device for Bayer process-based separation of iron in high-iron red mud |
| CN106319226A (en) * | 2016-08-22 | 2017-01-11 | 中国铝业股份有限公司 | Method for comprehensively recycling aluminium oxide, sodium oxide and ferric oxide from red mud |
| CN109179463A (en) * | 2018-11-07 | 2019-01-11 | 沈阳工业大学 | A kind of method of Bayer-red mud alkali soluble tandem process processing bauxite resource |
| CN109913656A (en) * | 2019-04-11 | 2019-06-21 | 东北大学 | A kind of method of the high-speed rail high recycling of titanium red mud iron and titanium and direct cement |
| CN111825113A (en) * | 2020-07-28 | 2020-10-27 | 沈阳工业大学 | Method for recovering aluminum oxide and sodium oxide from Bayer process red mud |
| CN113441519A (en) * | 2021-06-28 | 2021-09-28 | 广西田东锦鑫化工有限公司 | Bayer process red mud dealkalization and alkali recovery process |
| CN113979457A (en) * | 2021-12-07 | 2022-01-28 | 中国铝业股份有限公司 | Dealkalization method for Bayer process red mud |
-
2022
- 2022-04-01 CN CN202210339464.XA patent/CN114887759B/en active Active
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1334320A (en) * | 1961-10-30 | 1963-08-09 | Improvements in the processing of ores containing a magnetic or magnetizable element, and products thus obtained | |
| CN1613809A (en) * | 2004-11-25 | 2005-05-11 | 中国铝业股份有限公司 | Method for producing cement from red mud |
| CN1743472A (en) * | 2005-09-22 | 2006-03-08 | 贵阳铝镁设计研究院 | Method for recovering iron from red mud |
| CN101417261A (en) * | 2008-11-21 | 2009-04-29 | 中国铝业股份有限公司 | Bayer process red mud processing method |
| CN101912814A (en) * | 2010-08-09 | 2010-12-15 | 中国铝业股份有限公司 | Method for magnetic separation of iron ore concentrate in red mud slurry in alumina production flow by Bayer process |
| CN103898330A (en) * | 2014-03-28 | 2014-07-02 | 中国铝业股份有限公司 | Method for comprehensively recycling such valuable metals as iron, aluminum, scandium, titanium, vanadium and the like in red mud |
| CN104368440A (en) * | 2014-09-30 | 2015-02-25 | 中国铝业股份有限公司 | Novel technology and device for Bayer process-based separation of iron in high-iron red mud |
| CN106319226A (en) * | 2016-08-22 | 2017-01-11 | 中国铝业股份有限公司 | Method for comprehensively recycling aluminium oxide, sodium oxide and ferric oxide from red mud |
| CN109179463A (en) * | 2018-11-07 | 2019-01-11 | 沈阳工业大学 | A kind of method of Bayer-red mud alkali soluble tandem process processing bauxite resource |
| CN109913656A (en) * | 2019-04-11 | 2019-06-21 | 东北大学 | A kind of method of the high-speed rail high recycling of titanium red mud iron and titanium and direct cement |
| CN111825113A (en) * | 2020-07-28 | 2020-10-27 | 沈阳工业大学 | Method for recovering aluminum oxide and sodium oxide from Bayer process red mud |
| CN113441519A (en) * | 2021-06-28 | 2021-09-28 | 广西田东锦鑫化工有限公司 | Bayer process red mud dealkalization and alkali recovery process |
| CN113979457A (en) * | 2021-12-07 | 2022-01-28 | 中国铝业股份有限公司 | Dealkalization method for Bayer process red mud |
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