CN112299460A - Method for synergistically and efficiently oxidizing sulfur and organic matters in bauxite leaching slurry - Google Patents
Method for synergistically and efficiently oxidizing sulfur and organic matters in bauxite leaching slurry Download PDFInfo
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- C01F7/04—Preparation of alkali metal aluminates; Aluminium oxide or hydroxide therefrom
- C01F7/06—Preparation of alkali metal aluminates; Aluminium oxide or hydroxide therefrom by treating aluminous minerals or waste-like raw materials with alkali hydroxide, e.g. leaching of bauxite according to the Bayer process
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Abstract
The invention provides a method for synergistically and efficiently oxidizing sulfur and organic matters in bauxite leaching slurry, which belongs to the technical field of alumina production and comprises the following steps: installing a first oxygenator on an ore pulp preheating pipeline of a Bayer process alumina production system, wherein the temperature of ore pulp in the ore pulp preheating pipeline is more than or equal to 145 ℃; installing a second oxygenator on an ore pulp pipeline before the ore pulp enters the self-evaporator; and introducing oxygen into the first oxygenator and the second oxygenator to oxidize sulfur and organic matters in the ore pulp. The method not only can efficiently remove the sulfur in the bauxite stripping slurry, but also can efficiently remove the organic matters in the bauxite stripping slurry.
Description
Technical Field
The invention belongs to the technical field of alumina production, and relates to a method for synergistically and efficiently oxidizing sulfur and organic matters in bauxite leaching slurry.
Background
The major sulfur-containing mineral in bauxite is pyrite (FeS)2) And isomers thereof, such as pyrite and pyrrhotite, and gypsum CaSO4A class of sulfates and the like. In the Bayer process of alumina production, sulfur is firstly expressed as S2-Is brought into solution and gradually isBy oxidation to various forms of sulphur, e.g. SO3 2-、S2O3 2-And SO4 2-And the like. The major hazard of sulfur in the Bayer process is first expressed in S2-And S2O3 2-The corrosion process of ore pulp heating, a dissolution system and evaporation system equipment can be accelerated, so that great potential safety hazards are generated; secondly, the iron content in the alumina product is increased, and the chemical quality of the product is deteriorated; moreover, the existence of sulfur in the Bayer process brings corresponding difficulties to the operations of red mud sedimentation separation and mother liquor evaporation.
In order to solve the problem of removing sulfur in the production process of alumina, researchers have proposed various methods for removing sulfur in the production process of alumina, mainly including oxidation and precipitation.
A method for adding sodium nitrate into raw ore pulp for oxidative desulfurization is proposed in the document ' development and application of producing alumina by high-sulfur bauxite ' (Pengxin, light metals 2010(11) (14-17) '), and test results prove that the sodium nitrate is added into the raw ore pulp according to 0.5-1.5% of the bauxite, the raw ore pulp reacts for 1h at the temperature of 260 ℃, and most S in a dissolution liquid can be reacted for 1h2-By oxidation, but to S in solution2O3 2-The oxidation effect is not significant. When sodium nitrate is added for oxidative desulfurization, the method has the advantages of simple process and easy implementation, but the defects are obvious: the majority of S in the solution2-Can only be oxidized to S2O3 2-And S is2O3 2-Still can bring the adverse effect to the alumina production; in addition, the higher price of sodium nitrate leads to higher costs for oxidative desulfurization.
Document "with MnO2Removing S in industrial sodium aluminate solution2-The research of (Chenguru, etc. light metals 2011 (10): 20-24) proposes that MnO is added in the dissolution process of the sulfur-containing bauxite2Oxidizing and removing S in the dissolution liquid2-The method has the advantages of simple process flow and low equipment investment. However, due to the oxidizing agent MnO2The consumption is high, and the price of raw materials is high, so that the sulfur removal cost is high. This is achieved byIn addition, MnO is added2The manganese slag generated after the reaction enters a sedimentation system along with the red mud, so that the manganese slag is difficult to recover, and the pressure of a sedimentation process can be increased.
The method for oxidizing and desulfurizing by introducing air in the stripping process is proposed in the document 'development and application of alumina produced by high-sulfur bauxite' (Pengxin, et al. light metals 2010 (11): 14-17), and the industrial test result proves that under the conditions of the reaction temperature of 260 ℃ and the reaction time of about 15min, about 30-40% of S in the solution2-Is oxidized to S2O3 2-The method can not achieve the purpose of complete desulfurization, and because the nitrogen content of the air is high, the discharge amount of non-condensable gas generated after oxidative desulfurization is large, the heat loss in the dissolution process is serious, and the technical defects limit the application of the technology in production.
In the literature, "research on removing sulfur in sodium aluminate solution by wet oxidation" (picrorhiza et al, university of south and middle school, 2011, 42 (10): 2911-: the reaction temperature is 200 ℃, the oxygen pressure is 3.0MPa, and S is2-The concentration of (A) is 1g/L, the reaction time is not less than 40min, S2-The removal rate of (2) is 99%; or the reaction temperature is 260 ℃, the oxygen pressure is 1.0MPa, and S is2-The concentration of (A) is 1g/L, the reaction time is 60min, S2-The removal rate of (2) was 99%. The method has the advantages of2-The oxidation removal rate of (2) is high, but because oxygen is introduced into the high-pressure reaction kettle, the dispersion and mixing degree in slurry is not enough, and the oxygen reaction rate is low.
The technical group of the application proposes a sulfur removal method (application number is CN201210120380.3) in the production process of alumina, and discloses a method for introducing oxygen, air or a mixed gas thereof into a pre-desilication tank, a dilution tank or a high-pressure reaction kettle in the production process of alumina for oxidative desulfurization. The method is characterized in that the desulfurizing process comprises the steps of introducing air, oxygen or a mixed gas thereof into a pre-desiliconization tank or a dissolved slurry diluting tank, and carrying out oxidation reaction for 1-10 h at the temperature of 90-110 ℃, or introducing air, oxygen or a mixed gas thereof into the pre-desiliconization tank or the dissolved slurry diluting tankOxidizing in a high-pressure reaction kettle at 120-280 ℃ for 2-60 min to oxidize different forms of low-valence sulfur in the process of producing alumina by a Bayer process into high-valence SO4 2-. When oxygen is introduced for oxidative desulfurization, the oxygen is introduced into a high-pressure reaction kettle, a pre-desilication tank or a dilution tank and other large-volume reactors, the dispersion and mixing degree of the oxygen in slurry is insufficient, the effective contact time is short, the mass transfer effect between the oxygen and the slurry is poor, and the reaction rate is low.
In the patent of CN201310172901.4, "a method for low-temperature desulfurization of sodium aluminate solution", a method for oxidative desulfurization by introducing air into ore pulp from which high-sulfur bauxite is dissolved out is provided, the reaction temperature of oxidative desulfurization is 105-160 ℃, the reaction time is 1-3 h, and the desulfurization efficiency can reach more than 90%. Although air is used as an oxidant for oxidation and desulfurization, the raw material is low in price, but the defects of large quantity of non-condensable gas and serious heat loss are caused after oxidation and desulfurization.
The SO in the sodium aluminate solution can be caused by adding barium salt into the sodium aluminate solution4 2-Barium sulfate precipitate is generated, and although the desulfurization effect of the method is good, barium salt is extremely toxic and expensive, so that the method cannot be applied to production; another method for precipitation desulfurization is to add ZnO to make S in solution2-A ZnS precipitate is formed, which method also has the disadvantage that the higher price of the zinc-containing material leads to higher costs for desulphurization.
The sulfur-containing bauxite in China is generally high in organic carbon content, organic carbon in an alumina process is accumulated continuously, the content is continuously increased, and a lot of adverse effects are brought to alumina production, such as product granularity refinement, accelerated decomposition tank scab forming speed, overproof sodium content in product alumina and the like.
Foreign research on a method for removing organic matters in Bayer process solution is relatively more, and mainly comprises the following steps: crystallization, ion exchange, solution combustion, and the like. In the method, the crystallization method is only suitable for removing sodium oxalate in the sodium aluminate solution, and the removal effect on non-oxalate type organic matters is not good; the ion exchange method can only be used for removing specific organic matters in the sodium aluminate solution; although the solution combustion method is industrially applied, the solution combustion method has the problems of high cost and environmental protection caused by discharged gas after combustion.
In the literature, "research on removing organic matters in sodium aluminate solution by wet oxidation" (Chen gurn et al. Hunan nonferrous metallurgy 2011 (10): 35-37), a method for removing organic matters by introducing oxygen into sodium aluminate solution is proposed, and the preferable reaction conditions of the method are as follows: the temperature is 260 ℃, the oxygen partial pressure is 1.0MPa, the reaction time is 60min, and the conversion rate of organic matters reaches 64.1 percent. The method has the advantages of high reaction rate of organic oxidation and the disadvantages of long reaction time and low reaction rate of oxygen because the oxygen is introduced into the high-pressure reaction kettle and the dispersion and mixing degree of the oxygen in slurry are not enough.
The utility model discloses a utility model "a control alumina high temperature dissolves out device (application number is CN201420347397.7) of organic matter and sulphur is disclosed to a device that lets in oxygen oxidation solution sulphur and organic matter in Bayer process dissolves out thick liquid, and the device mainly includes: high-pressure oxygen buffer tank, oxygen conveying pipeline and tubular oxygen mixing reactor, tubular mixing reactor installs on the inlet pipe before the ore pulp gets into reation kettle, perhaps installs on the inlet pipe that the ore pulp got into first order self evaporator, perhaps on installing the hookup pipeline between adjacent 2 reation kettle, and tubular mixing reactor's quantity is 1 ~ 4. The content of organic carbon in the solution is 0.30-0.75 g/L, S2-The content is 0.3-2.45 g/L, the device is applied to react for 0.5-60 min under the conditions that the temperature is 200-280 ℃ and oxygen is introduced for 0.3-2.45 g/L, the removal rate of organic carbon in the solution reaches 35-70 percent, and more than 96 percent of S in the solution2-Is oxidized into SO4 2-The installation position of the tubular mixing reactor is not optimized according to the reaction behavior rules of the dissolution and oxidation of the pyrite and the organic matters in the ore in the dissolution process, so that the oxidation rate of the organic matters in the solution is low, and the effect is unstable.
The technical group of the application provides a method for synchronously oxidizing and eliminating sulfur and organic matters in bauxite digestion ore pulp (application forNo. CN201711273326.1) discloses a method for oxidizing sulfur and organic matters in bauxite leaching slurry by oxygen, which comprises injecting high-pressure oxygen with purity of more than 99% and pressure of 4.5-8.5 MPa into high-temperature leaching slurry, reacting at 240-280 deg.C for 0.5-45 min to obtain 40-99% S2-Is oxidized into SO4 2-And the absorbance (lambda is 578nm) of the solution is reduced by 6-65% after the organic matters in the solution are oxidized. The method reduces the requirement on equipment when applied in production, is beneficial to popularization and application, has a desulfurization effect close to that of the utility model with the application number of CN201420347397.7, but has a low organic matter removal rate.
Disclosure of Invention
The invention provides a method for synergistically and efficiently oxidizing sulfur and organic matters in bauxite leaching slurry, aiming at solving the technical problem of low removal rate of the organic matters in the bauxite leaching slurry.
The invention is realized by the following technical scheme:
a method for synergistically and efficiently oxidizing sulfur and organic matters in bauxite leaching slurry comprises the following steps:
installing a first oxygenator in Bayer process alumina production
The system is characterized in that the system is arranged on an ore pulp preheating pipeline, and the temperature of ore pulp in the ore pulp preheating pipeline is more than or equal to 145 ℃;
installing a second oxygenator on an ore pulp pipeline before the ore pulp enters the self-evaporator;
and introducing oxygen into the first oxygenator and the second oxygenator to oxidize sulfur and organic matters in the ore pulp.
Specifically, the first oxygenator and the second oxygenator are both in a pipeline structure, the first oxygenator is connected to the ore pulp preheating pipeline, the second oxygenator is connected to the ore pulp pipeline, and the ore pulp is mixed with oxygen when flowing through the first oxygenator and the second oxygenator.
Further, the amount of oxygen introduced into the first oxygenator is 0.3-3.0 g/L, and the amount of oxygen introduced into the second oxygenator is 0.3-2.5 g/L.
Further, the time for the ore pulp to pass through the first oxygen adding device is 1.0-20.0 min, and the time for the ore pulp to pass through the second oxygen adding device is 0.5-5.0 min.
Further, the flow rate of the ore pulp in the first oxygenator and the second oxygenator is 1.0-3.0 m/s.
Further, after the oxidation is finished, S in the ore pulp2-The oxidized proportion is more than or equal to 98 percent; the oxidation rate of organic matters in the ore pulp is more than or equal to 70 percent.
Further, the inner diameter of the first oxygenator is 0.20-0.60 m, and the inner diameter of the second oxygenator is 0.20-0.60 m.
Either the first oxygenator or the second oxygenator may be used alone, provided that it allows for a reduction in the effectiveness of sulfur and organic oxidation.
One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:
1. the invention relates to a method for synergistically and efficiently oxidizing sulfur and organic matters in bauxite leaching slurry, which comprises the steps of respectively introducing oxygen into high-temperature bauxite slurry from 2 oxygen adding points for 2 times according to different leaching speeds of sulfur and organic matters in the slurry, wherein through test, more than 58 percent of oxygen introduced by a 1 st oxygen adding device is used for oxidizing the organic matters in the solution, and more than 67 percent of oxygen introduced by a 2 nd oxygen adding device is used for oxidizing S in the solution2-Solution S2-Is oxidized into SO4 2-The proportion of the organic matters is more than or equal to 98 percent, and the oxidation rate of the organic matters newly entering the solution from the bauxite in the dissolution process is more than or equal to 70 percent.
2. The method for synergistically and efficiently oxidizing the sulfur and the organic matters in the bauxite leaching pulp improves the oxidation removal rate of the sulfur in the bauxite leaching pulp to more than 98 percent and the oxidation removal rate of the organic matters to more than 70 percent, and can shorten the total reaction time to be not more than 25min, thereby greatly reducing the investment cost of an oxygenator and being beneficial to the popularization and application of the technology.
Drawings
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 schematic process flow diagram of the present 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 provided to illustrate the invention, and not to limit 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 an existing method.
In order to solve the technical problems, the embodiment of the invention provides the following general ideas:
aiming at the defects in the prior art, the method for dissolving out the sulfur and the organic matters in the slurry by synergistically and efficiently oxidizing the bauxite is provided according to the reaction characteristics of the sulfur and the organic matters in the solution and oxygen.
The applicant has conducted intensive research on the dissolution reaction behavior of pyrite, which is a sulfur-containing mineral in bauxite, and the oxidation reaction behavior of pyrite in solution, and found that: since the sulfur-containing mineral pyrite in bauxite requires a long reaction time and is mainly S2-The form of (A) is taken into account in the solution; and the largest in the orePart of the organic matter enters the solution already during the pre-desiliconization and preheating of the ore pulp. During the co-oxidation process, S in solution2-Firstly, the reaction with oxygen is carried out, the reaction speed is high, generally only 1-5 min is needed, and the organic matters and S in the solution2O3 2-The reaction speed of (2) is relatively slow, and generally 5 to 15min is needed. In solution S2-When the organic matter is subjected to the synergistic oxidation reaction, the S in the solution is accompanied by the S2-Is rapidly oxidized, the partial pressure of oxygen in the reaction system is rapidly reduced, thereby causing organic matters and S2O3 2-The reaction speed of (2) becomes very slow, and a long reaction time is needed to complete the oxidation reaction process, so the adding mode of oxygen has a significant influence on the oxidation effect of sulfur and organic matters in the solution.
The invention fully considers the dissolving reaction behavior of sulfur-containing minerals in bauxite and S in solution2-And the characteristics of organic oxidation reaction kinetics, provides a new technical scheme: 1 oxygen adding device is respectively arranged on a preheating pipeline of dissolved ore pulp of bauxite and a pipeline before dissolved pulp enters a self evaporator, oxygen is respectively added into the high-temperature dissolved ore pulp of the bauxite through 2 oxygen adding devices, and tests show that more than 58% of oxygen introduced into the 1 st oxygen adding device is used for oxidizing organic matters in a solution, and more than 67% of oxygen introduced into the 2 nd oxygen adding device is used for oxidizing S in the solution2-。
Specifically, as shown in fig. 1, the method for synergistically and efficiently oxidizing sulfur and organic matters in bauxite leaching slurry according to the present invention comprises:
installing a first oxygenator in Bayer process alumina production
The system is characterized in that the system is arranged on an ore pulp preheating pipeline, and the temperature of ore pulp in the ore pulp preheating pipeline is more than or equal to 145 ℃;
installing a second oxygenator on an ore pulp pipeline before the ore pulp enters the self-evaporator;
and introducing oxygen into the first oxygenator and the second oxygenator to oxidize sulfur and organic matters in the ore pulp.
Further, the first oxygenator and the second oxygenator are both in a pipeline structure, the first oxygenator is connected to the ore pulp preheating pipeline, the second oxygenator is connected to the ore pulp pipeline, and the ore pulp is mixed with oxygen when flowing through the first oxygenator and the second oxygenator.
Further, the amount of oxygen introduced into the first oxygenator is 0.3-3.0 g/L, and the amount of oxygen introduced into the second oxygenator is 0.3-2.5 g/L.
Further, the time for the ore pulp to pass through the first oxygen adding device is 1.0-20.0 min, and the time for the ore pulp to pass through the second oxygen adding device is 0.5-5.0 min.
Further, the flow rate of the ore pulp in the first oxygenator and the second oxygenator is 1.0-3.0 m/s.
According to the invention, according to the different dissolving speeds of the sulfur and the organic matters in the ore pulp, a first oxygen adding device is connected to the ore pulp preheating pipeline, oxygen introduced by the first oxygen adding device is mixed with the ore pulp, and the organic matters and part of dissolved sulfur are oxidized; when the ore pulp flows to an ore pulp pipeline before the self-evaporator, sulfur in the ore pulp is completely dissolved out, and the sulfur in the ore pulp is oxidized by oxygen in the second oxygenator.
The invention adopts two times of oxygenation to oxidize ore pulp in different digestion stages according to different digestion speeds of sulfur and organic matters in the ore pulp, so that the oxidation is more thorough, and the removal rate of the organic matters and the sulfur is higher.
The following will explain in detail a method for synergistically and efficiently oxidizing sulfur and organic substances in a bauxite leaching slurry according to the present invention, with reference to examples, comparative examples and experimental data.
Example 1
In this example, the bauxite contains 56.29% of alumina, 10.01% of silica, 0.10% of sulfur, 0.10% of organic carbon, 243g/L of mother liquor Nk, ak2.90, lime addition 10%. Preheating ore pulp to 280 ℃, introducing the ore pulp into a 1 st oxygenator with the inner diameter of 0.20m, wherein the oxygen introduction amount is 0.4g/L, the flow velocity of the ore pulp is 3.0m/s, and the retention time is 1.0 min; passing through the 1 st oxygen adding deviceAfter 50-60 min, the ore pulp flows through 6 heat preservation retention tanks in sequence and enters a 2 nd oxygenator with the inner diameter of 0.20m, the oxygen introduction amount is 0.3g/L, the flow rate of the ore pulp is 3.0m/s, and the retention time is 0.5 min; and (3) cooling the ore pulp from the 2 nd oxygenator by a multi-stage self-evaporator to obtain the dissolved-out slurry.
S in the dissolved slurry is tested by a chemical titration method2-The oxidation removal rate of (1) is 98%, S2O3 2-The content of the sodium hydroxide is reduced by 25 percent, and the oxidation rate of organic matters entering the solution in the dissolution process reaches 72 percent. During the reaction, about 65% of oxygen introduced from the 1 st oxygenator is used for oxidizing the organic matters in the solution, and about 67% of oxygen introduced from the 2 nd oxygenator is used for oxidizing the S in the solution2-。
Example 2
In this example, the bauxite contains 57.31% alumina, 10.61% silica, 0.80% sulfur, 0.40% organic carbon, 243g/L Nk, ak2.90, lime addition 10%. Preheating ore pulp to 145 ℃, introducing into a 1 st oxygenator with the inner diameter of 0.27m, introducing oxygen in an amount of 3g/L, controlling the flow rate of the ore pulp to be 1.2m/s, and keeping the retention time to be 20.0 min; after 50-60 min, the ore pulp flowing through the 1 st oxygen adding device sequentially flows through 6 heat preservation retention tanks, and then enters the 2 nd oxygen adding device with the inner diameter of 0.27m, the oxygen introducing amount is 2.5g/L, the flow speed of the ore pulp is 1.2m/s, and the retention time is 3.0 min; the ore pulp from 2 oxygenators is cooled by a multi-stage self-evaporator to obtain the dissolved slurry.
S in the dissolved slurry is tested by a chemical titration method2-The oxidation removal rate of (1) is 98%, S2O3 2-The content of the organic matters is reduced by 30 percent, and the oxidation rate of the organic matters newly entering the solution in the dissolution process reaches 71 percent. During the reaction, about 67% of oxygen introduced from the 1 st oxygenator is used for oxidizing the organic matters in the solution, and about 71% of oxygen introduced from the 2 nd oxygenator is used for oxidizing the S in the solution2-。
Example 3
In this example, the bauxite contained 56.21% alumina, 9.65% silica and 0.60% sulfurThe content of organic carbon is 0.10 percent, the Nk of mother liquor is 240g/L, ak2.90, lime addition 10%. Preheating ore pulp to 270 ℃, introducing the ore pulp into a 1 st oxygenator with the inner diameter of 0.27m, wherein the oxygen introduction amount is 1.5g/L, the flow velocity of the ore pulp is 1.7m/s, and the retention time is 4.0 min; after 50-60 min, the ore pulp flowing through the 1 st oxygen adding device sequentially flows through 6 heat preservation retention tanks, and then enters the 2 nd oxygen adding device with the inner diameter of 0.27m, the oxygen introducing amount is 1.5g/L, the flow speed of the ore pulp is 1.2m/s, and the retention time is 1.5 min; the ore pulp from 2 oxygenators is cooled by a multi-stage self-evaporator to obtain the dissolved slurry.
S in the dissolved slurry is tested by a chemical titration method2-The oxidation removal rate of (1) is 98.5%, S2O3 2-The content of the organic matters is reduced by 30 percent, and the oxidation rate of the organic matters newly entering the solution in the dissolution process reaches 73 percent. During the reaction, about 58% of oxygen introduced from the 1 st oxygenator is used for oxidizing the organic matters in the solution, and about 87% of oxygen introduced from the 2 nd oxygenator is used for oxidizing S in the solution2-。
Example 4
In this example, the bauxite contains 55.51% of alumina, 10.86% of silica, 0.40% of sulfur, 0.31% of organic carbon, 243g/L of mother liquor Nk, ak2.90, lime addition 10%. Preheating ore pulp to 260 ℃, introducing into a 1 st oxygenator with the inner diameter of 0.27m, introducing oxygen in an amount of 2.0g/L, controlling the flow rate of the ore pulp to be 1.5m/s and the retention time to be 8 min; after 50-60 min, the ore pulp flowing through the 1 st oxygen adding device sequentially flows through 6 heat preservation retention tanks, and then enters the 2 nd oxygen adding device with the inner diameter of 0.27m, the oxygen introducing amount is 1.1g/L, the flow speed of the ore pulp is 1.2m/s, and the retention time is 1.5 min; the ore pulp from 2 oxygenators is cooled by a multi-stage self-evaporator to obtain the dissolved slurry.
S in the dissolved slurry is tested by a chemical titration method2-Has an oxidation removal rate of 99% and S2O3 2-The content of the organic matters is reduced by 35 percent, and the oxidation rate of the organic matters newly entering the solution in the dissolution process reaches 75 percent. During the reaction, about 69% of oxygen introduced from the 1 st oxygenator is used for oxidizing the organic matters in the solutionAbout 82% of the oxygen introduced from the 2 nd oxygenator was used to oxidize S in the solution2-。
Example 5
In this example, the bauxite contains 55.06% alumina, 9.86% silica, 0.20% sulfur, 0.30% organic carbon, 241g/L mother liquor Nk, ak2.92, lime addition 10%. Preheating ore pulp to 260 ℃, then feeding the ore pulp into a 1 st oxygenator with the inner diameter of 0.54m, wherein the oxygen introduction amount is 1.1g/L, the flow velocity of the ore pulp is 2.0m/s, and the retention time is 2.0 min; after 50-60 min, the ore pulp flowing through the 1 st oxygen adding device sequentially flows through 6 heat preservation retention tanks, and then enters the 2 nd oxygen adding device with the inner diameter of 0.54m, the oxygen introducing amount is 0.5g/L, the flow speed of the ore pulp is 2.0m/s, and the retention time is 0.5 min; the ore pulp from 2 oxygenators is cooled by a multi-stage self-evaporator to obtain the dissolved slurry.
S in the dissolved slurry is tested by a chemical titration method2-Has an oxidation removal rate of 99% and S2O3 2-The content of the organic matters is reduced by 25 percent, and the oxidation rate of the organic matters newly entering the solution in the dissolution process reaches 72 percent. During the reaction, about 76% of oxygen is introduced from the 1 st oxygenator to oxidize organic matters in the solution, and about 90% of oxygen is introduced from the 2 nd oxygenator to oxidize S in the solution2-。
Example 6
In this example, the bauxite contains 57.06% alumina, 9.86% silica, 0.20% sulfur, 0.30% organic carbon, 241g/L mother liquor Nk, ak2.92, lime addition 10%. Preheating ore pulp to 265 ℃, then feeding the ore pulp into a 1 st oxygenator with the inner diameter of 0.54m, wherein the oxygen introduction amount is 1.0g/L, the flow velocity of the ore pulp is 1.0m/s, and the retention time is 6.0 min; after 50-60 min, the ore pulp flowing through the 1 st oxygen adding device sequentially flows through 6 heat preservation retention tanks, and then enters the 2 nd oxygen adding device with the inner diameter of 0.54m, the oxygen introducing amount is 0.6g/L, the flow speed of the ore pulp is 1.0m/s, and the retention time is 3.0 min; the ore pulp from 2 oxygenators is cooled by a multi-stage self-evaporator to obtain the dissolved slurry.
In the dissolution slurry by chemical titration testS2-Has an oxidation removal rate of 99% and S2O3 2-The content of the organic matters is reduced by 35 percent, and the oxidation rate of the organic matters newly entering the solution in the dissolution process reaches 74 percent. During the reaction, about 75% of oxygen introduced from the 1 st oxygenator is used for oxidizing the organic matters in the solution, and about 72% of oxygen introduced from the 2 nd oxygenator is used for oxidizing S in the solution2-。
Example 7
In this example, the bauxite contains 58.70% alumina, 9.32% silica, 0.10% sulfur, 0.10% organic carbon, 245g/L of mother liquor Nk, ak2.92, lime addition 10%. Preheating ore pulp to 260 ℃, then feeding the ore pulp into a 1 st oxygenator with the inner diameter of 0.60m, wherein the oxygen introduction amount is 0.3g/L, the flow velocity of the ore pulp is 2.0m/s, and the retention time is 2.0 min; after 50-60 min, the ore pulp flowing through the 1 st oxygen adding device sequentially flows through 6 heat preservation retention tanks, and then enters the 2 nd oxygen adding device with the inner diameter of 0.60m, the oxygen introducing amount is 0.3g/L, the flow speed of the ore pulp is 1.0m/s, and the retention time is 2.0 min; the ore pulp from 2 oxygenators is cooled by a multi-stage self-evaporator to obtain the digestion slurry.
S in the dissolved slurry is tested by a chemical titration method2-Has an oxidation removal rate of 99% and S2O3 2-The content of the organic matters is reduced by 31 percent, and the oxidation rate of the organic matters newly entering the solution in the dissolution process reaches 73 percent. During the reaction, about 61% of oxygen introduced from the 1 st oxygenator is used for oxidizing the organic matters in the solution, and about 69% of oxygen introduced from the 2 nd oxygenator is used for oxidizing the S in the solution2-。
Example 8
In this example, the bauxite contains 58.90% of alumina, 9.62% of silica, 0.10% of sulfur, 0.40% of organic carbon, 241g/L of mother liquor Nk, ak2.92, lime addition 10%. Preheating ore pulp to 280 ℃, then feeding the ore pulp into a 1 st oxygenator with the inner diameter of 0.60m, wherein the oxygen introduction amount is 1.0g/L, the flow velocity of the ore pulp is 1.5m/s, and the retention time is 15.0 min; the ore pulp flowing through the 1 st oxygenator sequentially flows through 6 heat-preservation retention tanks after 50-60 min, and then enters the tank with the inner diameter ofThe oxygen inlet amount of the 2 nd oxygenator of 0.60m is 0.3g/L, the flow rate of ore pulp is 1.0m/s, and the retention time is 3.0 min; the ore pulp from 2 oxygenators is cooled by a multi-stage self-evaporator to obtain the dissolved slurry.
S in the dissolved slurry is tested by a chemical titration method2-Has an oxidation removal rate of 99% and S2O3 2-The content of the organic matters is reduced by 45 percent, and the oxidation rate of the organic matters newly entering the solution in the dissolution process reaches 81 percent. During the reaction, about 87% of oxygen introduced from the 1 st oxygenator is used for oxidizing the organic matters in the solution, and about 70% of oxygen introduced from the 2 nd oxygenator is used for oxidizing the S in the solution2-。
Example 9
In this example, the bauxite contains 55.31% of alumina, 10.25% of silica, 0.45% of sulfur, 0.35% of organic carbon, 241g/L of mother liquor Nk, ak2.92, lime addition 10%. Preheating ore pulp to 260 ℃, then feeding the ore pulp into a 1 st oxygenator with the inner diameter of 0.27m, wherein the oxygen introduction amount is 2.40g/L, the flow velocity of the ore pulp is 2.0m/s, and the retention time is 8 min; after 50-60 min, the ore pulp flowing through the 1 st oxygen adding device sequentially flows through 6 heat preservation and retention tanks, and then enters the 2 nd oxygen adding device with the inner diameter of 0.27m, the oxygen introducing amount is 1.30g/L, the flow speed of the ore pulp is 2.0m/s, and the retention time is 2 min; the ore pulp from 2 oxygenators is cooled by a multi-stage self-evaporator to obtain dissolved pulp.
S in the dissolved slurry is tested by a chemical titration method2-Has an oxidation removal rate of 99% and S2O3 2-The content of the organic matters is reduced by about 40 percent, and the oxidation rate of the organic matters entering the solution in the dissolution process reaches 75 percent. During the reaction, about 65% of oxygen introduced from the 1 st oxygenator is used for oxidizing the organic matters in the solution, and about 96% of oxygen introduced from the 2 nd oxygenator is used for oxidizing the S in the solution2-。
Comparative example 1
1 oxygen injector is arranged on the ore pulp preheating pipeline: the bauxite of this comparative example had an alumina content of 55.31%, a silica content of 10.25%, a sulfur content of 0.45%, and an organic carbon content of 0.35% of mother liquor Nk is 245g/L, ak2.92, and the addition amount of lime is 10%. Preheating ore pulp to 260 ℃, then feeding the ore pulp into a 1 st oxygenator with the inner diameter of 0.27m, wherein the oxygen introduction amount is 3.80g/L, the flow velocity of the ore pulp is 1.5m/s, and the retention time is 50 min; and (3) allowing the ore pulp flowing through the 1 st oxygenator to sequentially flow through 6 heat-preservation retention tanks after 50-60 min, and then allowing the ore pulp to enter a multistage self-evaporator for cooling to obtain dissolved slurry.
S in the dissolved slurry is tested by a chemical titration method2-Has an oxidation removal rate of 75% and S2O3 2-The content of the organic matters is reduced by about 20 percent, and the oxidation rate of the organic matters entering the solution in the dissolution process reaches 76 percent. During the reaction, about 60% of oxygen introduced from the oxygenator is used for oxidizing S in the solution2-About 40% of the oxygen fed from the oxygenator is used to oxidize the organics in the solution.
Comparative example 2
An oxygen injector is arranged on a pipeline before the dissolved ore pulp enters the self-evaporator: in the bauxite of the comparative example, the content of alumina is 55.31 percent, the content of silicon dioxide is 10.25 percent, the content of sulfur is 0.45 percent, the content of organic carbon is 0.35 percent, the Nk of mother liquor is 245g/L, ak2.92, lime addition 10%. The ore pulp is preheated to 260 ℃, then enters into 6 heat preservation retention tanks after flowing for 50-60 min in sequence, then enters into 1 oxygen adding device with the inner diameter of 0.27m, the oxygen input is 3.50g/L, the flow rate of the ore pulp is 2.0m/s, the retention time is 15min, and the ore pulp from the oxygen adding device enters into a multistage self-evaporator again to be cooled to obtain the dissolving-out slurry.
S in the dissolved slurry is tested by a chemical titration method2-Has an oxidation removal rate of 99% and S2O3 2-The content of the organic matters is reduced by about 30 percent, and the oxidation rate of the organic matters entering the solution in the dissolution process reaches 73 percent. During the above reaction, about 43% of oxygen introduced from the oxygenator was used to oxidize S in the solution2-Approximately 57% of the oxygen fed from the oxygenator is used to oxidize the organics in the solution.
Comparison of the technical effects of comparative examples 1, 2 and example 9 is given in Table 1 below
Table 1: technical effects and implementation conditions of comparative examples 1 and 2 and example 9
As can be seen from table 1: from S2-The oxidation effect of the compound is seen to be poor in comparative example 1, and the effects of comparative example 2 and example 9 are relatively close; the oxidation effects of the organic matters of the three schemes of the comparative example 1, the comparative example 2 and the example 9 are relatively close; from the viewpoint of oxygen consumption, the oxygen consumption of comparative example 2 is small, and the oxygen consumption of comparative example 1 is the highest; from the reaction time point of view, the reaction time of example 9 is the shortest, the reaction time is two thirds of that of comparative example 2, and the reaction time of example 9 is less than one fifth of that of comparative example 1; the lengths of the additional oxygenators required to achieve comparative example 1, comparative example 2 and example 9 were 4500m, 1800m and 1200m, respectively, i.e. the solution of example 9 was the least expensive to build. Although comparative example 2 had the least oxygen consumption, the length of the newly added oxygenator tubing was almost 1.5 times that of example 9. Therefore, the scheme of technical example 9 of the present invention is most economically feasible by comprehensively considering the oxidation effect, the oxygen consumption amount, and the construction investment cost.
The principle explanation about the difference in oxygen consumption amounts of comparative example 1, comparative example 2 and example 9: the oxygen introduction reaction time of the comparative example 1 is long, and the reaction product S is generated in the process of dissolving out the pyrite which is the sulfur-containing mineral in the ore2-Continuously oxidized until the reaction end point, so that the leaching rate of the pyrite in the final ore is higher, and the produced S2-The amount is large, so the amount of oxygen consumed is large; in contrast, for comparative example 2, S in solution was continuously eluted with pyrite, a sulfur-containing mineral in the ore2-The content is continuously increased due to the higher concentration of S in the solution2-The subsequent dissolution reaction rate of the pyrite is reduced, thus resulting in a lower total dissolution rate of the pyrite in the ore than in comparative example 1, and therefore the oxygen consumption is minimal; in example 9, the retention time in the first oxygen injector was short, so that the dissolution rate of pyrite in the ore was not greatly affected, and the oxygen consumption was close to that of comparative example 2.
It can be seen from the above examples and comparative examples that the present invention can effectively oxidize sulfur and organic substances in ore pulp by installing two oxygenators, the first oxygenator being installed on the ore pulp preheating pipeline of the bayer process alumina production system, and the second oxygenator being installed on the ore pulp pipeline before the ore pulp enters the self-evaporator, and the present invention has higher oxidation efficiency and lowest engineering construction cost compared with the existing method.
Finally, 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.
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 (7)
1. A method for synergistically and efficiently oxidizing sulfur and organic matters in bauxite leaching slurry is characterized by comprising the following steps:
installing a first oxygenator on an ore pulp preheating pipeline of a Bayer process alumina production system, wherein the temperature of ore pulp in the ore pulp preheating pipeline is more than or equal to 145 ℃;
installing a second oxygenator on an ore pulp pipeline before the ore pulp enters the self-evaporator;
and introducing oxygen into the first oxygenator and the second oxygenator to oxidize sulfur and organic matters in the ore pulp.
2. The method as claimed in claim 1, wherein the first oxygenator and the second oxygenator are both in a pipeline structure, the first oxygenator is connected to the ore pulp preheating pipeline, the second oxygenator is connected to the ore pulp pipeline, and the ore pulp is mixed with oxygen while flowing through the first oxygenator and the second oxygenator.
3. The method as claimed in claim 1, wherein the first oxygenator is configured to introduce oxygen in an amount of 0.3-3.0 g/L, and the second oxygenator is configured to introduce oxygen in an amount of 0.3-2.5 g/L.
4. The method as claimed in claim 1, wherein the time for the ore pulp to pass through the first oxygenator is 1.0-20.0 min, and the time for the ore pulp to pass through the second oxygenator is 0.5-5.0 min.
5. The method as claimed in claim 1, wherein the flow rates of the ore slurries in the first and second oxygenators are 1.0-3.0 m/s.
6. The method as claimed in claim 1, wherein the S in the ore slurry is oxidized after the oxidation process2-The oxidized proportion is more than or equal to 98 percent; the oxidation rate of the organic matters in the ore pulp is more than or equal to 70 percent.
7. The method as claimed in claim 1, wherein the first oxygenator has an inner diameter of 0.20-0.60 m, and the second oxygenator has an inner diameter of 0.20-0.60 m.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1419439A (en) * | 1972-03-30 | 1975-12-31 | Giulini Gmbh Geb | Preparation of alumina |
| US4994244A (en) * | 1989-01-31 | 1991-02-19 | Alcan International Limited | Process for producing alumina from bauxite |
| WO1994018122A1 (en) * | 1993-02-01 | 1994-08-18 | Alcan International Limited | Process and apparatus for the extraction of gibbsitic alumina from bauxite |
| CN102674415A (en) * | 2012-04-24 | 2012-09-19 | 中国铝业股份有限公司 | Sulphur removal method in aluminum oxide production by bauxite |
| CN203360022U (en) * | 2013-07-10 | 2013-12-25 | 中国铝业股份有限公司 | Oxidative desulfurization device for production of aluminum oxide |
| CN203998986U (en) * | 2014-06-27 | 2014-12-10 | 中国铝业股份有限公司 | A kind of device of controlling alumina high temperature stripping organism and sulphur |
| CN108046301A (en) * | 2017-12-06 | 2018-05-18 | 中国铝业股份有限公司 | A kind of Simultaneous Oxidation eliminates the method for sulphur and organic matter in bauxite dissolved mineral slurry |
-
2020
- 2020-10-27 CN CN202011167593.2A patent/CN112299460B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1419439A (en) * | 1972-03-30 | 1975-12-31 | Giulini Gmbh Geb | Preparation of alumina |
| US4994244A (en) * | 1989-01-31 | 1991-02-19 | Alcan International Limited | Process for producing alumina from bauxite |
| WO1994018122A1 (en) * | 1993-02-01 | 1994-08-18 | Alcan International Limited | Process and apparatus for the extraction of gibbsitic alumina from bauxite |
| CN102674415A (en) * | 2012-04-24 | 2012-09-19 | 中国铝业股份有限公司 | Sulphur removal method in aluminum oxide production by bauxite |
| CN203360022U (en) * | 2013-07-10 | 2013-12-25 | 中国铝业股份有限公司 | Oxidative desulfurization device for production of aluminum oxide |
| CN203998986U (en) * | 2014-06-27 | 2014-12-10 | 中国铝业股份有限公司 | A kind of device of controlling alumina high temperature stripping organism and sulphur |
| CN108046301A (en) * | 2017-12-06 | 2018-05-18 | 中国铝业股份有限公司 | A kind of Simultaneous Oxidation eliminates the method for sulphur and organic matter in bauxite dissolved mineral slurry |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113428883A (en) * | 2021-07-22 | 2021-09-24 | 昆明理工大学 | Method for removing sulfur and organic matters in bauxite |
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