CN113857209B - Red mud recycling method and application thereof - Google Patents
Red mud recycling method and application thereof Download PDFInfo
- Publication number
- CN113857209B CN113857209B CN202111122659.0A CN202111122659A CN113857209B CN 113857209 B CN113857209 B CN 113857209B CN 202111122659 A CN202111122659 A CN 202111122659A CN 113857209 B CN113857209 B CN 113857209B
- Authority
- CN
- China
- Prior art keywords
- red mud
- acidolysis
- recycling
- flotation
- agent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
- B09B—DISPOSAL OF SOLID WASTE
- B09B3/00—Destroying solid waste or transforming solid waste into something useful or harmless
-
- 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
- B03B—SEPARATING SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS
- B03B1/00—Conditioning for facilitating separation by altering physical properties of the matter to be treated
-
- 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
- B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
- B03D1/00—Flotation
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F11/00—Compounds of calcium, strontium, or barium
- C01F11/46—Sulfates
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F5/00—Compounds of magnesium
- C01F5/14—Magnesium hydroxide
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F7/00—Compounds of aluminium
- C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
-
- 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 provides a method for recycling red mud and application thereof, comprising the following steps: preparing red mud into red mud slurry, performing acidolysis to control the iron dissolution amount to be less than 5%, performing flotation and desiliconization to obtain red mud-based iron ore, taking the red mud-based iron ore as a soil remediation agent, and simultaneously recovering aluminum, calcium and magnesium. The red mud-based iron ore with TFe of more than 56% is obtained, and the total recovery rate of iron can reach more than 80%; the wet process is adopted, the reaction condition is mild, the reaction does not need to be carried out at high temperature, and the energy consumption is low; the raw materials used in the process flow are few in variety, the equipment requirement is low, and the cost is saved; low-concentration hydrochloric acid is adopted for acidolysis, so that the cementation of carbonate and silicate in the red mud is broken, and flotation enrichment becomes possible; and a reverse flotation desilication method is adopted, so that the dosage of the medicament is less, and the subsequent operation is simple.
Description
Technical Field
The invention relates to the technical field of industrial waste processing, in particular to a method for recycling red mud and application thereof.
Background
In the preparation process of the alumina, most of aluminum in the bauxite is dissolved out by alkali when the bauxite is dissolved out by strong alkali, and impurities such as iron, titanium, calcium, magnesium and the like and most of silicon are not dissolved to form red mud residues. The red mud yield varies with the ore grade and the alumina production method. The quantity of red mud produced every year in the world is huge, and it is estimated that 1.0 ton of alumina is produced along with 1.0-1.8 ton of red mud by-product in China at present, and the red mud discharged every year in the alumina industry is about 6000 million tons.
The red mud contains about 3 percent of alkali, the pH value is 11.0-12.3, the corrosivity is strong, and the waste is nearly dangerous. At present, alumina manufacturers generally adopt methods such as flat ground building, river valley blocking, concave filling and the like to pile up the red mud. Therefore, the method not only occupies land resources, but also causes harmful substances in the red mud to permeate underground to pollute water and soil. In addition, the sewage generated by washing the red mud with rainwater can also pollute water and soil. In a word, the stacking of a large amount of red mud causes environmental pollution and damages ecological balance.
Meanwhile, the red mud is also a resource. The red mud component is related to the raw bauxite component and the alumina production process. With the increase of the amount of imported bauxite in China and the adoption of the Bayer process, the iron content in the red mud can reach more than 30 percent. The shortage of iron resources in China is especially along with the rapid development of the steel industry, and the iron resources are increasingly reduced. In addition, the red mud can adsorb heavy metal ions in the soil and be complexed with the heavy metal ions, so the red mud can be used as a repairing agent for the heavy metal polluted soil to treat the soil pollution and repair the ecological balance. Under the double pressure of resource depletion and environmental protection, the processing and comprehensive utilization of the red mud are significant.
The invention with the application number of CN201710976695.0 discloses a method for recovering iron from red mud, which comprises the specific operations of carrying out strong magnetic separation on the red mud, and then sequentially carrying out pre-oxidation, reduction, reoxidation suspension roasting and magnetic separation treatment. The process flow has the defects of complex operation, higher roasting temperature, toxic reducing gas CO, high energy consumption, higher cost and the like.
The invention with the application number of CN202011514868.5 discloses a comprehensive utilization method of red mud by a full-wet method, which comprises the steps of primary leaching of red mud by dilute hydrochloric acid, secondary leaching of treated filter residue by adding sulfuric acid, precipitation of iron, aluminum, titanium and scandium by adding alkali liquor into treated filtrate, and recovery of calcium in the red mud. The method has the advantages of complex operation process and long period through multiple acidolysis and precipitation filtration.
Because the release speed of free alkali in the red mud is very high, if the red mud powder is directly used as a soil remediation agent, the soil can be seriously damaged. The invention patent with the application number of CN201510793560.1 discloses a red mud particle soil repairing agent and a preparation method thereof, the red mud is used as a raw material to prepare the soil repairing agent with certain mechanical strength and stable and curable property of heavy metal, and release of free alkali in the red mud is slowed down, but the method adds various cementing materials besides gypsum, so that the reaction period is long, the utilization rate of the red mud is low, and the recovery of iron in the red mud is not introduced.
In view of the above, there is a need to design an improved method for recycling red mud and application thereof, which can reduce energy consumption, improve resource utilization rate, and reduce recycling cost, so as to solve the above problems.
Disclosure of Invention
The invention aims to provide a method for recycling red mud and application thereof, which solve the problems of limited resource utilization, higher energy consumption, higher extraction cost, difficult industrial application and the like of the traditional dressing and smelting method, recycle calcium, magnesium, aluminum, iron and the like in the red mud, use red mud-based iron ore as a soil remediation agent and reasonably utilize solid waste red mud resources generated in the alumina industry.
In order to realize the purpose, the invention provides a red mud recycling method, which comprises the following steps:
s1, fine grinding: mixing water and red mud according to the liquid-solid mass ratio of 3.0-5.0, adding the mixture into a mill, and carrying out wet milling to obtain red mud I;
s2, acid hydrolysis: adding an acidolysis agent into the red mud fluid I obtained in the step S1, stirring and carrying out acidolysis for a preset time under the condition that the pH value is 3.0-6.5, and controlling the elution amount of iron in the red mud to be less than 5% to prepare red mud fluid II;
s3, solid-liquid separation: carrying out solid-liquid separation on the red mud liquid II in the step S2 to obtain middlings and acidolysis liquid;
s4, salinization: adding water and the middlings in the step S3 into flotation equipment according to the liquid-solid mass ratio of 3.0-8.0, adding a flotation reagent for flotation desilicification, wherein the finally obtained flotation foam is tailings, and the underflow is red mud-based iron ore
As a further improvement of the invention, the part with the granularity of 74 mu m of the red mud slurry in the step S1 accounts for more than 70 percent of the total weight.
As a further improvement of the invention, the acidolysis agent in the step S2 is dilute hydrochloric acid with the mass concentration of 1-10%.
As a further improvement of the present invention, the preset time for acid hydrolysis is 1 hour or more.
As a further improvement of the invention, the method for recycling the red mud also comprises the following steps: s5, regeneration: and (4) adding a regenerant lime milk into the acidolysis solution obtained in the step (S3), sequentially separating out aluminum hydroxide precipitate and magnesium hydroxide precipitate, and adding sulfuric acid to generate gypsum and dilute hydrochloric acid to realize acidolysis agent regeneration.
As a further improvement of the present invention, the flotation reagent in step S4 includes a modifier, a depressant, a collector, and a foaming agent.
As a further improvement of the invention, the regulator is one or more of quicklime, lime milk, sodium hydroxide and sodium carbonate, and the dosage is 500-2000 g/t; the inhibitor is one or more of starch, modified starch, dextrin, sodium carboxymethylcellulose, resin, tannin, sulfonated lignin and humate, and the dosage is 0-1000 g/t; the collecting agent is one or more of alkyl primary amine salt of C12-C18, ether amine salt and fuel oil, and the using amount of the collecting agent is 20-500 g/t.
As a further improvement of the invention, the step S2 is to stir at the normal temperature or the high temperature at the rotating speed of 200-1000 r/min.
As a further improvement of the present invention, the solid-liquid separation in step S3 is any one of precipitation, draining or filtration.
The invention also provides application of the red mud-based iron ore, and the red mud-based iron ore prepared by the method for recycling the red mud is used as a soil remediation agent.
The beneficial effects of the invention are:
(1) According to the red mud recycling method provided by the invention, the red mud-based iron ore with TFe of more than 56% is obtained by a method combining primary acidolysis and flotation, the total recovery rate of iron can reach more than 80%, calcium, magnesium and aluminum are recovered at the same time, and the utilization rate of the red mud is high.
(2) The method for recycling the red mud provided by the invention adopts a wet process, has mild reaction conditions, does not need to be carried out at high temperature, and has low energy consumption; the process flow has the advantages of few raw material types, low equipment requirement and cost saving.
(3) According to the method for recycling the red mud, calcium, magnesium, sodium and other components in the red mud are preferentially dissolved out during low-concentration hydrochloric acid hydrolysis, the cementing action of carbonate and silicate in the red mud is broken, and iron minerals and other minerals are dissociated, so that flotation enrichment is possible; and a reverse flotation desilication method is adopted, so that the dosage of the medicament is less, and the subsequent operation is simple.
(4) The method for recycling the red mud realizes the regeneration and the cyclic utilization of the acidolysis solution by using the sulfuric acid, the lime and the like with low price.
(5) The invention provides application of red mud-based iron ore for a soil remediation agent, and provides a preparation method of a novel soil remediation agent.
Drawings
Fig. 1 is a process flow diagram for red mud recycling according to the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in detail with reference to the accompanying drawings and specific embodiments.
It should be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and/or processing steps closely related to the aspects of the present invention are shown in the drawings, and other details not closely related to the present invention are omitted.
In addition, it is also to 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.
Referring to fig. 1, the present invention provides a method for recycling red mud, comprising the following steps:
s1, fine grinding: mixing water and red mud with the liquid-solid mass ratio of 3.0-5.0, adding the mixture into a mill, and wet-milling to obtain red mud I with the particle size of-74 mu m (the particle size is below 74 mu m) and the part accounting for at least 70 percent of the total weight. Through fine grinding, various mineral components in the red mud are mechanically dissociated, so that the subsequent acidolysis process is facilitated.
S2, acid hydrolysis: adding the red mud slurry I obtained in the step S1 into a stirrer, stirring at the speed of 200-1000 rpm, simultaneously adding a dilute hydrochloric acid acidolysis agent with the mass concentration of 1-10% to ensure that the pH value of the whole process is 3.0-6.5, preferably controlling the pH value to be 3.5-4.5, stirring for acidolysis for more than 1 hour, preferably acidolysis for 3 hours, and preparing the red mud slurry II. Preferably, the acid hydrolysis is carried out at normal temperature or high temperature of 5 to 90 ℃ (increasing the temperature may improve the working efficiency but may deteriorate the working environment), and more preferably, the acid hydrolysis is carried out at a temperature range of 5 to 45 ℃. When the acid concentration is low, the elution amount of iron, silicon, titanium, etc. in the red mud is less than 5%, and calcium carbonate, magnesium carbonate, sodium silicate, alumina, etc. are preferentially eluted. The process takes place as follows:
CaCO 3 +2HCl＝CaCl 2 +H 2 O+CO 2 ↑ (1)
MgCO 3 +2HCl＝MgCl 2 +H 2 O+CO 2 ↑ (2)
Na 2 CO 3 +2HCl＝2NaCl+H 2 O+CO 2 ↑ (3)
Na 2 SiO 3 +2HCl＝2NaCl+H 2 O+SiO 2 (4)
Al 2 O 3 +6HCl＝2AlCl 3 +3H 2 O (5)
the cementation of calcite, aragonite and partial silicate can be destroyed through acidolysis, and the chemical dissociation among minerals in the red mud is promoted.
S3, solid-liquid separation: and (3) carrying out solid-liquid separation on the red mud slurry II obtained in the step (S2) by any method of precipitation, draining or filtration and the like to obtain middlings (also called acidolysis slag) and acidolysis solution. Wherein the filtering method can be carried out by selecting modes such as suction filtration, filter pressing, centrifugal dehydration and the like. Washing the obtained middlings with clean water for 1-3 times, removing soluble impurities and ensuring the quality of the middlings.
S4, salinization: and (4) adding water into the middling obtained in the step (S3), adding the middling into flotation equipment according to the mass ratio of water to middling liquid to solid of 3.0-8.0, further adding a flotation reagent, and performing flotation desilicification through 1-5 times of roughing and 0-3 times of scavenging, wherein the obtained flotation foam is tailings, and the underflow is red mud-based iron ore. The added flotation agents are regulators, inhibitors, collectors, foaming agents and the like. The regulator is one or more of quicklime, lime milk, sodium hydroxide and sodium carbonate, the dosage is 500-2000 g/t, and the regulator can regulate the flotation environment to a proper pH value; the inhibitor is one or more of starch, modified starch, dextrin, sodium carboxymethylcellulose, resin, tannin, sulfonated lignin and humate, the dosage is 0-1000 g/t, and the inhibitor increases the hydrophilicity of the surface of the iron ore and inhibits the upward floating of the iron ore; the collecting agent is one or more of alkyl primary amine salt, ether amine salt and fuel oil of C12-C18, the dosage is 20-500 g/t, and the silicon is easy to float by the adsorption of the catching agent by the catching agent; the foaming agent is pine oil, 2 # Any suitable foaming agent in oil, 4-methyl-2-pentanol, sec-octanol, fusel oil and polyethylene glycol, wherein the dosage of the foaming agent is 0-100 g/t, and the foaming agent can further improve the flotation efficiency.
S5, regeneration: continuously adding a regenerant lime milk into the acidolysis solution obtained in the step S4, adjusting the pH value of the acidolysis solution to 4.5-5.5 to obtain aluminum hydroxide precipitate, and carrying out solid-liquid separation; adding lime milk continuously to adjust the pH value of the acidolysis solution to 10.0-12.0 to obtain magnesium hydroxide precipitate, and performing solid-liquid separation again; finally, the adding amount of sulfuric acid is determined according to the concentration of calcium ions in the acidolysis solution, and dilute hydrochloric acid acidolysis agent with the mass concentration of 1-10% is generated while calcium sulfate precipitate is generated (Ca in the acidolysis agent is controlled) 2+ The concentration is not less than 0.5 g.L -1 ) The acidolysis agent is circularly used in the acidolysis process. The obtained byproduct aluminum hydroxide can be further utilized as a raw material in the production process of aluminum oxide(ii) a The obtained magnesium hydroxide and gypsum can be directly sold. The process takes place as follows:
2AlCl 3 +3Ca(OH) 2 ＝2Al(OH) 3 ↓+3CaCl 2 (6)
MgCl 2 +Ca(OH) 2 ＝Mg(OH) 2 ↓+CaCl 2 (7)
CaCl 2 +H 2 SO 4 ＝CaSO 4 ↓+2HCl (8)
the invention is described in detail below by means of a number of examples:
example 1:
in this example, red mud produced by the Guangxi branch of aluminum is selected as a raw material, and the main components and contents of the red mud are shown in Table 1 (unit wt%).
Table 1 shows the main components and contents of red mud of Guangxi division of aluminum
| Components | Fe 2 O 3 | Al 2 O 3 | SiO 2 | TiO 2 | CaO | MgO | Na 2 O |
| Content (wt.) | 36.6 | 18.8 | 8.5 | 4.8 | 17.6 | 1.1 | 3.6 |
1. pH value exploration during acidolysis
S1, fine grinding: adding 100 parts by weight of water and 30 parts by weight of red mud into a ball mill, and carrying out wet ball milling to obtain first red mud slurry;
s2, acid hydrolysis: adding the red mud slurry I obtained in the step S1 into a stirrer, adding a dilute hydrochloric acid acidolysis agent with the mass concentration of 2% while stirring, adjusting the pH value of the red mud slurry to 3.1-4.0, 4.1-5.0 and 5.1-6.0 respectively, and detecting at any time, wherein the acidolysis time is 3.0 hours to prepare a red mud slurry II;
s3, solid-liquid separation: and (3) filtering the red mud slurry II obtained in the step (S2) to obtain middlings and acidolysis solution. Analysis revealed that the dissolution rates of iron, aluminum, titanium, calcium, sodium, etc. upon acid hydrolysis at different pH values are shown in Table 2 (in wt%).
TABLE 2 influence of different pH values on the dissolution rate of each element
| pH of acidolysis | Fe | Al | Ti | Si | Ca | Na |
| 3.1～4.0 | 4.34 | 33.25 | 0.56 | 0.36 | 76.45 | 91.87 |
| 4.1～5.0 | 3.12 | 28.87 | 0.32 | 0.26 | 66.76 | 86.45 |
| 5.1～6.0 | 2.08 | 21.36 | 0.11 | 0.23 | 61.49 | 81.69 |
As can be seen from table 2, the dissolution rate of each element tended to decrease as the pH increased. In order to reduce the iron elution rate and to elute calcium, sodium, and aluminum as much as possible, the pH is preferably controlled to 3.5 to 4.5.
2. Study on acid hydrolysis time
S1, fine grinding: adding 100 parts by weight of water and 30 parts by weight of red mud into a ball mill, and carrying out wet ball milling to obtain first red mud slurry;
s2, acid hydrolysis: adding the red mud slurry I obtained in the step S1 into a stirrer, adding a dilute hydrochloric acid acidolysis agent with the mass concentration of 2% while stirring, adjusting the pH value of the red mud slurry to 3.5-4.5, and detecting at any time, wherein the acidolysis time is 1.0, 2.0, 3.0 and 4.0 hours respectively to prepare a red mud slurry II;
s3, solid-liquid separation: and (3) filtering the red mud slurry II obtained in the step (S2) to obtain middlings and acidolysis solution. Analysis revealed that the dissolution rates of iron, aluminum, titanium, calcium, sodium, etc. are shown in Table 3 (in wt.%) depending on the acid hydrolysis time.
TABLE 3 Effect of acid hydrolysis time on dissolution Rate of elements
| Time of acid hydrolysis | Fe | Al | Ti | Si | Ca | Na |
| 1.0 | 3.53 | 26.69 | 0.46 | 0.29 | 70.70 | 85.65 |
| 2.0 | 3.56 | 29.87 | 0.50 | 0.32 | 73.64 | 88.75 |
| 3.0 | 3.55 | 31.31 | 0.48 | 0.35 | 76.56 | 91.79 |
| 4.0 | 3.54 | 33.09 | 0.47 | 0.36 | 78.23 | 92.11 |
As shown in Table 3, the dissolution rates of Fe, ti, si, etc. remained substantially unchanged with the increase of the acid hydrolysis time, while the dissolution rates of Al, ca, na, etc. increased, and the acid hydrolysis time should preferably be controlled to be 3.0 hours or more.
3. Salinization
The salinization is carried out by taking the middlings obtained by acidolysis for 3.0 hours at the pH value of 3.5-4.5 as raw materials, and comprises the following steps:
s1, adding water and the obtained middlings into a flotation machine according to a liquid-solid mass ratio of 3.0;
s2, adding Na with the mass ratio of 1:1 into the flotation machine 2 CO 3 Mixing the sodium hydroxide with NaOH to obtain a mixed regulator, wherein the addition amount of the mixed regulator is 800g/t;
s3, adding inhibitor modified starch into the flotation machine, and stirring for 2 minutes, wherein the adding amount is 500g/t;
s4, adding a collecting agent into the flotation machine for 4 times of rough separation, and adding a foaming agent for 1 time of scavenging; the roughing adopts a catching agent with the mass ratio of lauryl amine hydrochloride to C14 ether diamine acetate to diesel = 50; 1 time of scavenging adopts 2 # Oil is used as foaming agent in an amount of 10g/t.
The red mud-based iron ore obtained from middling and the middling grade TFe, the yield and the recovery rate of tailings are shown in Table 4 (unit%).
Mineralisation results in Table 4
| Middling | Red mud-based iron ore | Tailings | |
| Grade TFe | 41.8 | 58.1 | 16.1 |
| Yield of the product | 100 | 61.2 | 38.8 |
| Recovery rate | 100 | 85.1 | 14.9 |
As can be seen from Table 4, the TFe of the middling obtained after the acid hydrolysis of the red mud is increased to 41.8%, the red mud-based iron ore with the TFe of 58.1% is prepared by the middling salinization, the total recovery rate of iron can reach 85.1%, and the recovery rate is high.
Example 2:
in this example, red mud produced by the subsidiary company of Henan of China, aluminum, was selected as a raw material, and the main components and contents of the red mud are shown in Table 5 (unit wt%).
Table 5 Main Components and contents of Red mud of the al Henan division
| Fe 2 O 3 | Al 2 O 3 | SiO 2 | TiO 2 | CaO | MgO | Na 2 O |
| 12.9 | 25.8 | 16.2 | 6.6 | 23.6 | 1.3 | 3.1 |
S1, fine grinding: adding 100 parts by weight of water and 25 parts by weight of food red mud into a ball mill, and carrying out wet ball milling to obtain first red mud slurry;
s2, acid hydrolysis: adding the red mud slurry I obtained in the step S1 into a stirrer, adding a dilute hydrochloric acid acidolysis agent with the mass concentration of 3% while stirring, adjusting the pH value of the red mud slurry to be 3.5-4.5, detecting at any time, and carrying out acidolysis for 4.0 hours to obtain red mud slurry II;
s3, solid-liquid separation: and (3) filtering the red mud slurry II obtained in the step (S2) to obtain middlings and acidolysis solution. The analysis showed that the main components and contents of the obtained middlings are shown in Table 6 (unit wt%).
TABLE 6 Main Components and contents of middlings obtained by acid hydrolysis
| Fe 2 O 3 | Al 2 O 3 | SiO 2 | TiO 2 | CaO | MgO | Na 2 O |
| 25.3 | 19.4 | 31.5 | 8.9 | 12.3 | 0.3 | 0.1 |
S4, adding water and the middling obtained in the step S3 into a flotation machine according to a liquid-solid mass ratio of 3.5;
s5, adding regulator quicklime powder into the flotation machine, wherein the addition amount is 1200g/t;
s6, adding a collecting agent into the flotation machine to carry out salinization for 5 times of roughing; the method comprises the following steps of (1) adopting a capturing agent comprising lauryl amine acetate, ether amine acetate and kerosene =50 in a mass ratio of 20g/t for 1 time, and 10g/t for 2 times, 3 times, 4 times and 5 times of roughing.
When no inhibitor is added in the salinization process, the red mud-based iron ore obtained from middling and the medium grade TFe of tailings, the yield and the recovery rate are shown in the following table 7 (unit%).
TABLE 7 middling salination results without inhibitor addition
| Middling | Red mud-based iron ore | Tailings of mine | |
| Grade TFe | 25.3 | 56.1 | 5.6 |
| Yield of the product | 100 | 39.1 | 60.9 |
| Recovery rate | 100 | 86.7 | 13.3 |
As can be seen from table 7, the yield of the red mud-based iron ore is low without adding the inhibitor, but the total recovery rate of iron is high, up to 86.7%, and the overall effect is good when the red mud-based iron ore with the site TFe of 56.1% is prepared by middling salinization.
Example 3:
in this example, red mud produced by Guangxi silver and aluminum industries, inc. was selected as a raw material, and the main components and contents of the red mud are shown in Table 8 (unit wt%).
TABLE 8 Guangxi silver aluminium industry company Red mud Main Components and contents
| Fe 2 O 3 | Al 2 O 3 | SiO 2 | TiO 2 | CaO | MgO | Na 2 O |
| 35.3 | 16.8 | 9.9 | 5.7 | 17.8 | 0.3 | 3.1 |
S1, fine grinding: adding 100 parts by weight of water and 33 parts by weight of red mud into a ball mill, and carrying out wet ball milling to obtain red mud I.
S2, acid hydrolysis: adding the red mud slurry I obtained in the step S1 into a stirrer, adding a dilute hydrochloric acid acidolysis agent with the mass concentration of 5% while stirring, adjusting the pH value of the red mud slurry to 3.5-4.5, detecting at any time, and carrying out acidolysis for 4.0 hours to obtain red mud slurry II;
s3, solid-liquid separation: and (3) filtering the red mud slurry II obtained in the step (S2) to obtain middlings and acidolysis solution. The TFe of the obtained middling iron grade is calculated to be 41.8%.
S4, adding water and the obtained middlings into a flotation machine according to a liquid-solid mass ratio of 4.0;
s5, adding a regulator quicklime powder into the flotation machine, wherein the adding amount is 1600g/t;
s6, adding inhibitor sodium humate into the flotation machine, wherein the adding amount is 300g/t;
s7, adding collecting agents and foaming agents with different amounts into a flotation machine to carry out salinization of roughing for 5 times; the method comprises the following steps of (1) adding 30% of a trapping agent comprising lauryl amine acetate, ether amine acetate, kerosene and polyethylene glycol = 40; the total using amount of the test collecting agent is 120g/t, 100g/t, 80g/t and 60g/t respectively.
When the amount of the scavenger is different, the grade TFe, the yield and the recovery rate of the red mud-based iron ore obtained from middling are shown in table 9 (unit%).
TABLE 9 Effect of Capture agent dosage on salinization results
| 0 | 60g/t | 80g/t | 100g/t | 120g/t | |
| Grade TFe | 41.8 | 53.5 | 56.0 | 59.3 | 62.7 |
| Yield of the product | 100 | 70.7 | 65.0 | 59.1 | 53.9 |
| Recovery rate | 100 | 90.5 | 87.1 | 83.8 | 80.9 |
As can be seen from Table 9, the soil remediation agent TFe gradually increased with increasing amount of the capture agent; although the yield and the recovery rate are gradually reduced, the overall result is ideal, and the total recovery rate of iron can reach more than 80%.
In conclusion, the invention provides a red mud recycling method and application thereof, the acidolysis and the flotation method are combined to obtain the red mud-based iron ore with TFe of more than 56%, the total recovery rate of iron can reach more than 80%, and meanwhile, calcium, magnesium and aluminum are recovered, so that the red mud utilization rate is high; the wet process is adopted, the reaction condition is mild, the reaction does not need to be carried out at high temperature, and the energy consumption is low; the raw materials used in the process flow are few in variety, the equipment requirement is low, and the cost is saved; during acidolysis of low-concentration hydrochloric acid, calcium, magnesium, sodium and other components in the red mud are preferentially dissolved out, the cementing action of carbonate and silicate in the red mud is broken, and iron minerals and other minerals are dissociated, so that flotation enrichment becomes possible; and a reverse flotation desilication method is adopted, so that the dosage of the medicament is small, and the subsequent operation is simple; the regeneration and the cyclic utilization of the acidolysis solution are realized by using the sulfuric acid, the lime and the like with low price; the generated red mud-based iron ore is used for a soil remediation agent, and a novel preparation method of the soil remediation agent is provided.
Although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the spirit and scope of the present invention.
Claims (8)
1. A method for recycling red mud is characterized by comprising the following steps: the method comprises the following steps:
s1, fine grinding: mixing water and red mud according to the liquid-solid mass ratio of 3.0-4.0, adding the mixture into a mill, and carrying out wet milling to obtain red mud I;
s2, acid hydrolysis: adding an acidolysis agent into the red mud fluid I obtained in the step S1, stirring and carrying out acidolysis for a preset time under the condition that the pH value is 3.5-4.5, and controlling the elution amount of iron in the red mud to be less than 5% to prepare red mud fluid II; wherein the acidolysis agent is dilute hydrochloric acid with the mass concentration of 1-10%;
s3, solid-liquid separation: carrying out solid-liquid separation on the red mud liquid II in the step S2 to obtain middlings and acidolysis liquid;
s4, salinization: adding water and the middlings in the step S3 into flotation equipment according to the liquid-solid mass ratio of 3.0-4.0, adding a flotation reagent for flotation desilicification, wherein finally obtained flotation foam is tailings, and underflow is red mud-based iron ore;
s5, regeneration: and (4) adding a regenerant lime milk into the acidolysis solution obtained in the step (S3), sequentially separating out aluminum hydroxide precipitate and magnesium hydroxide precipitate, and adding sulfuric acid to generate gypsum and dilute hydrochloric acid to realize acidolysis agent regeneration.
2. The method for recycling red mud according to claim 1, wherein the method comprises the following steps: in step S1, the part of the red mud slurry I with the granularity of less than 74 μm at least accounts for 70% of the total weight of the red mud slurry I.
3. The method for recycling red mud according to claim 1, wherein the method comprises the following steps: the preset acidolysis time is more than 1 hour.
4. The method for recycling red mud according to claim 1, which is characterized in that: the flotation reagent in the step S4 comprises a regulator, an inhibitor, a collector and a foaming agent.
5. The method for recycling red mud according to claim 4, wherein the method comprises the following steps: the regulator is one or more of quicklime, lime milk, sodium hydroxide and sodium carbonate, and the dosage is 500-2000 g/t; the inhibitor is one or more of starch, modified starch, dextrin, sodium carboxymethylcellulose, resin, tannin, sulfonated lignin and humate, and the dosage is 0-1000 g/t; the collecting agent is one or more of alkyl primary amine salt of C12-C18, ether amine salt and fuel oil, and the using amount of the collecting agent is 20-500 g/t.
6. The method for recycling red mud according to claim 1, which is characterized in that: and the step S2 is stirring at normal temperature or high temperature at the rotating speed of 200-1000 rpm.
7. The method for recycling red mud according to claim 1, which is characterized in that: the solid-liquid separation in step S3 is any one of precipitation, draining, or filtration.
8. The application of the red mud-based iron ore prepared by the red mud recycling method of any one of claims 1 to 7 is characterized in that: the red mud-based iron ore is used for a soil remediation agent.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111122659.0A CN113857209B (en) | 2021-09-24 | 2021-09-24 | Red mud recycling method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111122659.0A CN113857209B (en) | 2021-09-24 | 2021-09-24 | Red mud recycling method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113857209A CN113857209A (en) | 2021-12-31 |
| CN113857209B true CN113857209B (en) | 2023-01-24 |
Family
ID=78993857
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111122659.0A Active CN113857209B (en) | 2021-09-24 | 2021-09-24 | Red mud recycling method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113857209B (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6248302B1 (en) * | 2000-02-04 | 2001-06-19 | Goldendale Aluminum Company | Process for treating red mud to recover metal values therefrom |
| CN102127642A (en) * | 2011-03-26 | 2011-07-20 | 太原理工大学 | Method for enriching rare-earth elements from red mud |
| CN105219968A (en) * | 2015-10-20 | 2016-01-06 | 郑州大学 | The method of titanium and iron in a kind of acidleach-precipitate flotation combined recovery red mud |
| CN108043404A (en) * | 2017-12-20 | 2018-05-18 | 中国科学院过程工程研究所 | Catalyst of removing volatile organic compounds prepared by a kind of red mud and preparation method thereof |
| KR101900672B1 (en) * | 2018-04-10 | 2018-09-20 | 한국지질자원연구원 | Smelting method of ilmenite concentrate using Red mud |
| CN109957657A (en) * | 2019-03-22 | 2019-07-02 | 昆明理工大学 | A method of from red mud simultaneously resource utilization iron, sodium, aluminium |
| CN111690810A (en) * | 2019-03-12 | 2020-09-22 | 中南大学 | Red mud recycling-soil treatment method |
| CN111960645A (en) * | 2020-08-12 | 2020-11-20 | 矿冶科技集团有限公司 | Red mud-based dehydrating agent, preparation method thereof and dehydration method of bauxite ore washing slime |
| CN112011691A (en) * | 2020-08-28 | 2020-12-01 | 何耀 | Efficient resource utilization method for red mud |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SK281359B6 (en) * | 1998-04-14 | 2001-02-12 | Mária Kušnierová | Method for treatment of waste red mud from aluminium production |
-
2021
- 2021-09-24 CN CN202111122659.0A patent/CN113857209B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6248302B1 (en) * | 2000-02-04 | 2001-06-19 | Goldendale Aluminum Company | Process for treating red mud to recover metal values therefrom |
| CN102127642A (en) * | 2011-03-26 | 2011-07-20 | 太原理工大学 | Method for enriching rare-earth elements from red mud |
| CN105219968A (en) * | 2015-10-20 | 2016-01-06 | 郑州大学 | The method of titanium and iron in a kind of acidleach-precipitate flotation combined recovery red mud |
| CN108043404A (en) * | 2017-12-20 | 2018-05-18 | 中国科学院过程工程研究所 | Catalyst of removing volatile organic compounds prepared by a kind of red mud and preparation method thereof |
| KR101900672B1 (en) * | 2018-04-10 | 2018-09-20 | 한국지질자원연구원 | Smelting method of ilmenite concentrate using Red mud |
| CN111690810A (en) * | 2019-03-12 | 2020-09-22 | 中南大学 | Red mud recycling-soil treatment method |
| CN109957657A (en) * | 2019-03-22 | 2019-07-02 | 昆明理工大学 | A method of from red mud simultaneously resource utilization iron, sodium, aluminium |
| CN111960645A (en) * | 2020-08-12 | 2020-11-20 | 矿冶科技集团有限公司 | Red mud-based dehydrating agent, preparation method thereof and dehydration method of bauxite ore washing slime |
| CN112011691A (en) * | 2020-08-28 | 2020-12-01 | 何耀 | Efficient resource utilization method for red mud |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113857209A (en) | 2021-12-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111302377A (en) | Method for removing impurities and whitening ardealite | |
| US11478801B2 (en) | Method for separating calcite-rich low-grade fluorite barite paragenic ore | |
| CN107694762B (en) | A kind of composition and method for floating of the flotation collecting rutile from ore | |
| CN106006688B (en) | A kind of method of calcification carbonation step method processing Bayer process red mud | |
| CN110292991A (en) | A kind of fluorite method for concentrating | |
| CN101121151A (en) | Bauxite surface preprocessing-reverse floatation desiliconizing method | |
| CN112474065B (en) | Method for selecting phosphorus from low-grade vanadium titano-magnetite tailings | |
| CN109821660A (en) | A kind of processing of fluorspar ores separation method | |
| CN106622671A (en) | Direct flotation desiliconization and acid leaching magnesium removal combination treatment technology for phosphate ores | |
| WO2019218295A1 (en) | Efficient purification method for high-silicon, high-calcium, high-iron and low-grade brucite | |
| CN113857209B (en) | Red mud recycling method and application thereof | |
| CN107913802B (en) | A method of from selecting flotation recovery fluorite in tin tailings | |
| WO2024040891A1 (en) | Treatment method for carbonate lithium clay | |
| CN108722681B (en) | Silicon slag flotation method for effectively improving recovery rate of silicon metal | |
| CN113560031B (en) | High-calcium fluorite flotation inhibitor and preparation method and application process thereof | |
| CN209849075U (en) | Sorting system of carbonate type fluorite ore | |
| CN105583085B (en) | Flotation method for recovering sulfur and aluminum from low-aluminum-silicon-ratio aluminum trihydrate tailings | |
| CN112007759B (en) | Double-reverse middling direct flotation method for treating low-magnesium high-iron aluminum silicon calcium collophanite | |
| CN113245070A (en) | Treatment of copper ions in ore pulp from carbon pulp process | |
| CN110882828A (en) | Beneficiation method for recovering niobium mineral from carbonic acid type pyrochlore | |
| CN111036412A (en) | Application of high-efficiency inhibitor HPMA in positive flotation and magnesium removal of phosphate ore | |
| CN110976103A (en) | Flotation combination method for purifying iron oxide dip-dyed quartz | |
| CN111017974A (en) | Mineral processing technology for resource utilization of low-grade celestite | |
| WO2024036697A1 (en) | Method for enrichment of lithium from lithium clay ore | |
| CN115807172B (en) | Method for extracting valuable elements from vanadium shale |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |