CN115710632A - Method for extracting vanadium from high-carbon stone coal through step-by-step microwave roasting-ultrasonic microbubble acid leaching - Google Patents
Method for extracting vanadium from high-carbon stone coal through step-by-step microwave roasting-ultrasonic microbubble acid leaching Download PDFInfo
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Abstract
A method for vanadium extraction from high-carbon stone coal by step microwave roasting-ultrasonic microbubble acid leaching belongs to the field of vanadium extraction. The method comprises the steps of crushing and grinding high-carbon stone coal, preheating and roasting the ground high-carbon stone coal, decarburizing and roasting, then carrying out a fluid microwave roasting process, and carrying out an ultrasonic microbubble acid leaching process on an obtained roasted product. The method is firstly pre-roasted to avoid subsequent sintering; then the roasting effect of the high-carbon stone coal is strengthened through fluid microwave roasting; finally, the leaching efficiency of the roasted product is enhanced through ultrasonic microbubble acid leaching. The high-carbon stone coal particles in the microwave field absorb microwave energy and convert the microwave energy into heat energy, so that the inside and the outside of the coal particles are rapidly heated. According to the wave-absorbing characteristic difference of each mineral, the vanadium-containing mineral is selectively heated; in the leaching process, the ultrasonic wave can generate strong cavitation, a large number of small bubbles are generated in the solution, and high temperature and high pressure are generated at the bubble fracture part and between two phases, so that the full contact of a liquid-solid interface is more effectively promoted, and the vanadium diffusion and dissolution are enhanced.
Description
Technical Field
The invention relates to the technical field of vanadium extraction, in particular to a method for extracting vanadium from high-carbon stone coal by step-by-step microwave roasting-ultrasonic microbubble acid leaching.
Background
High-carbon stone coal (also called stone coal) is shale containing a large amount of dispersed carbonized organic matters and is also an important vanadium-containing resource. The existing vanadium extraction process of high-carbon stone coal mainly comprises direct leaching and roasting-leaching. Wherein, the roasting mainly comprises sodium roasting, calcifying roasting, composite additive roasting, blank roasting and the like; the leaching process mainly comprises acid leaching, alkali leaching and water leaching. Wherein, blank roasting-leaching is an environment-friendly and effective high-carbon stone coal vanadium extraction process. The traditional shaft furnace and rotary kiln have the fatal defects of insufficient gas-solid reaction, difficult control of roasting conditions, uneven roasting effect and the like.
The carbon content of carbon in carbonaceous shale is generally high, and sintering is easily caused by direct high-temperature roasting. However, the ordinary sectional roasting has slow heating rate and slow cooling rate, so that the decarburization roasting temperature is not easy to control, and sintering is still easy to cause.
In addition, the existing roasting process has poor effect on refractory high-carbon stone coal in the form of similar figures. Because the crystal lattice of the vanadium-containing mineral is difficult to be completely destroyed only by high temperature, the microwave heating technology can be used for heating the ore and strengthening the crystal lattice destruction at the same time. The principle of the microwave heating technology is different from the traditional heating, and the inside and the outside of material particles simultaneously absorb electromagnetic waves and convert the electromagnetic waves into heat energy, so that the inside and the outside of the particles are synchronously heated and the speed is very high. However, the microwave roasting process only needs to be carried out on the high-carbon stone coal with higher carbon content (the carbon content is more than or equal to 8%) to cause serious sintering, so that how to realize the crystal lattice damage at high temperature can not cause serious sintering, and the technical problem of the roasting process of the high-carbon stone coal is solved.
In addition, for the high-carbon stone coal mine difficult to leach, the leaching efficiency in a normal state is low, the oxidation effect on low-valence vanadium is poor, the consumption of the leaching agent is large, and the leaching time is long, so that the production cost is high.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a method for extracting vanadium from high-carbon stone coal by microwave roasting-ultrasonic microbubble acid leaching in steps, and aims to solve the problems of poor roasting efficiency and low leaching efficiency of refractory high-carbon stone coal with high carbon content (more than or equal to 8%) in the blank roasting-leaching process.
The invention combines the microwave heating technology and the fluid roasting technology to strengthen the blank roasting effect of the high-carbon stone coal, and achieves the purposes of improving the reaction mass and heat transfer efficiency, improving the heating rate and strengthening the crystal lattice damage of the vanadium-containing mineral.
In the step-by-step microwave roasting, the invention avoids sintering in the subsequent microwave roasting process by pre-roasting, thereby realizing the applicability of the process to the vanadium shale with higher carbon content. In addition, in the fluid microwave roasting process, microwave heating roasting is adopted, and the fluid microwave roasting device has the characteristics of fast temperature rise and fast temperature reduction. When the temperature of the decarbonization product is too high, the microwave generator automatically stops working, and the decarbonization product loses a heat source immediately to reduce the temperature, so that the sintering in the fluid microwave roasting process is avoided.
The invention enhances the leaching efficiency of the roasted product by an ultrasonic microbubble acid leaching technology, and realizes the purposes of efficiently oxidizing low-valence vanadium, reducing the dosage of a leaching agent, shortening the leaching time and effectively improving the vanadium leaching rate.
In order to realize the purpose of the invention, the technical scheme adopted by the invention is as follows:
the invention provides a method for extracting vanadium from high-carbon stone coal by step-by-step microwave roasting-ultrasonic microbubble acid leaching, and the specific embodiment is as follows.
1. And (3) crushing:
the crushing process comprises two working procedures of crushing and grinding; the method comprises the steps of crushing high-carbon stone coal with the granularity of 20-400 mm to 1-12 mm, grinding ore to-0.045 mm accounting for 65-80%, and obtaining the ground high-carbon stone coal.
2. Preheating and roasting:
carrying out preheating roasting operation on the ground high-carbon stone coal, wherein the preheating roasting temperature is 600-700 ℃, the preheating roasting retention time is 20-30 s, in the process, the adsorption water in the ground high-carbon stone coal can be removed, and the ground high-carbon stone coal is heated to 400-500 ℃ through preheating roasting to obtain the preheated high-carbon stone coal.
3. And (3) decarburization roasting process:
and (3) performing decarburization roasting operation on the preheated high-carbon stone coal, wherein the temperature is controlled to be 600-650 ℃. Introducing air from bottom to top in the decarburization roasting process, and adjusting the roasting air amount to 4m 3 /h～6m 3 H is used as the reference value. In the process, most of the carbon in the raw ore is removed by combustion, and the vanadium in the raw ore is enriched in the ash. The suspended material in the furnace is heated uniformly, and sintering caused by local high temperature can be prevented. The process can also remove the components of the adsorption water, partial crystal water and volatile matters in the raw ore. After the fine ore reacts in the equipment for 30 min-50 min, a decarburization product with uniform and stable properties is obtained.
4. Fluid microwave roasting process:
performing fluid microwave roasting on the decarbonized product, and introducing air and O in the fluid microwave roasting process 2 Regulating and controlling roasting gas quantity and O 2 Concentration; wherein, according to the volume ratio, air: o is 2 (1-2) in the total gas amount of 8m by regulating 3 /h～12m 3 The power of the microwave is 35kW to 50kW, and the microwave roasting temperature of the fluid is controlled to be 850 ℃ to 900 ℃. After the temperature of the material rises, the mica and illite minerals are subjected to dehydroxylation reaction, the silicon-oxygen octahedral structure where the vanadium ions in the crystal lattice are located is unstable, and the constraint of the mineral crystal lattice on the vanadium ions is greatly weakened. In order to ensure that the vanadium-containing mineral crystal lattice is fully damaged, the reaction time of the materials in the equipment is 50-80 min, and a roasted product is obtained.
5. An ultrasonic microbubble acid leaching process:
vanadium in the calcined product is present in the +3 and +4 valence forms in most cases. The ultrasonic wave acts on the leaching agent to generate strong cavitation, a large number of micro bubbles are generated in the solution, and the low-valence vanadium is oxidized into the +4 and +5 valence forms, which is very beneficial to the leaching of the vanadium. The bubbles can vibrate, grow or be broken along with the vibration of the surrounding solution, and high temperature and high pressure are generated at the bubble breakage part and between the two phases, so that the full contact of a liquid-solid interface is effectively promoted, and the dissolution of vanadium is enhanced. Thereby reducing the dosage of the leaching agent, shortening the leaching time and improving the vanadium leaching rate. Mixing the roasted product with a leaching agent to perform an ultrasonic microbubble acid leaching process, wherein in the ultrasonic microbubble acid leaching process, the ultrasonic power is 8-15 kW, the leaching agent adopts concentrated sulfuric acid, the concentrated sulfuric acid accounts for 8-20% of the roasted product by mass percent, and the weight ratio of (concentrated sulfuric acid + water): 1g of roasted product (2-3) mL, leaching temperature of 80-90 ℃ and leaching time of 1-1.5 h to obtain a high vanadium solution and leached slag with low vanadium content.
In the first step, a jaw crusher is adopted for crushing; the ore grinding adopts one of a semi-autogenous mill, an overflow type ball mill or a stirring mill.
In the method for extracting vanadium from high-carbon stone coal by step microwave roasting-ultrasonic microbubble acid leaching, the leaching rate of vanadium in the high-carbon stone coal can reach 80-90% by calculating the content of vanadium in a high-vanadium solution, and the leaching solution obtained after vanadium in the high-vanadium solution is extracted can be recycled as a leaching agent.
The invention relates to a method for extracting vanadium from high-carbon stone coal by step microwave roasting-ultrasonic microbubble acid leaching, which has the technical key points that:
1. the invention strengthens the roasting effect of the high-carbon stone coal by a microwave technology. In the microwave field, the high-carbon stone coal particles can absorb microwave energy and convert the microwave energy into heat energy, so that the temperature inside and outside the particles can be rapidly increased. In addition, according to the difference of the wave absorbing characteristics of the minerals, the vanadium-containing minerals are selectively heated.
2. The invention improves the leaching efficiency of the roasted product by an ultrasonic microbubble acid leaching technology. The ultrasonic wave acts on the leaching agent to generate strong cavitation, a large amount of small bubbles are generated in the solution, and the bubbles continuously move, grow or are broken along with the vibration of the leaching agent, so that high temperature and high pressure are generated at the broken part of the bubbles and between two phases, the full contact of a liquid-solid interface is effectively promoted, and the dissolution, diffusion and dissolution of vanadium are enhanced. Thereby reducing the dosage of the leaching agent, shortening the leaching time and improving the vanadium leaching rate.
3. The invention strengthens the roasting effect of the high-carbon stone coal by a fluid roasting process. The fluid roasting has the advantages of full gas-solid contact, high mass and heat transfer efficiency, low operation cost, environmental protection and the like. And the decarburization roasting is performed in advance to avoid sintering in the subsequent microwave roasting process, so that the applicability of the process to vanadium shale with high carbon content is realized.
Compared with the prior art, the method for extracting vanadium from high-carbon stone coal by step-by-step microwave roasting-ultrasonic microbubble acid leaching has the beneficial effects that:
(1): the invention strengthens the roasting effect of the high-carbon stone coal by a microwave heating technology and fluid roasting. In the microwave field, the high-carbon stone coal particles can absorb microwave energy and convert the microwave energy into heat energy, so that the temperature inside and outside the particles can be rapidly increased. In addition, according to the difference of wave-absorbing characteristics of various minerals, the vanadium-containing minerals are selectively heated; the fluid roasting has the advantages of full gas-solid contact, high mass and heat transfer efficiency, low operation cost, environmental protection and the like.
(2): according to the invention, the sintering in the subsequent microwave roasting process is avoided by pre-decarbonizing roasting, so that the applicability of the process to the vanadium shale with higher carbon content is realized.
(3): the invention improves the leaching efficiency of the roasted product by an ultrasonic microbubble acid leaching technology. The ultrasonic wave is utilized to generate strong cavitation in the leaching agent, thereby promoting the full contact of a liquid-solid interface and enhancing the dissolution of vanadium. Meanwhile, the dosage of the leaching agent is reduced, and the leaching time is shortened.
Drawings
FIG. 1 is a schematic diagram of a process of microwave roasting-ultrasonic microbubble acid leaching in steps for high-carbon stone coal.
FIG. 2 is a schematic diagram showing the change of materials in the preheating roasting device.
FIG. 3 is a schematic view showing a change of materials in the decarburization roasting apparatus.
FIG. 4 is a schematic diagram of a material change of the fluid microwave roasting device.
FIG. 5 is a schematic diagram showing the change of materials in the ultrasonic microbubble acid leaching device.
Detailed Description
The technical solution in the implementation of this patent will be clearly and completely described below with reference to the embodiments and the accompanying drawings. It should be noted that the examples described herein are for further explanation and illustration only and are not intended to limit the scope of the application. All other embodiments, which can be derived by a person skilled in the art from the invention without inventive step, are within the scope of protection of the invention.
The method for extracting vanadium from high-carbon stone coal by microwave roasting step by step and ultrasonic microbubble acid leaching comprises the following steps that a fluid microwave roasting system is adopted, and comprises a preheating roasting device, a decarburization roasting device and a fluid microwave roasting device, wherein a combustion station is arranged at the lower part of the preheating roasting device and is communicated with air and combustible gas; the outer wall of the decarburization roasting device is provided with an electric heating sleeve for heating the furnace chamber of the decarburization roasting device, and the bottom of the decarburization roasting device is communicated with the air; the outer wall of the fluid microwave roasting device is provided with a microwave heating sleeve which is used for generating a microwave field and generating electromagnetic energy to rapidly heat material particles; the bottom of the fluid microwave roasting device is communicated with air and oxygen gas sources.
The combustible gas is preferably one of natural gas and coke oven gas.
The method for extracting vanadium from high-carbon stone coal by step microwave roasting-ultrasonic microbubble acid leaching comprises the following steps of:
1. and (3) crushing: the material crushing process consists of two steps of crushing and grinding. The ore feeding granularity of the high-carbon stone coal is within the range of 20 mm-400 mm. Feeding ore, crushing to 1-12 mm with jaw crusher, and grinding with semi-autogenous mill, overflow ball mill or stirring mill to-0.045 mm in 65-80%.
2. Preheating and roasting: the high carbon stone coal is fed into the first stage of fluid microwave roasting system, i.e. preheating roasting operation, and the material change of the preheating roasting device is shown in figure 2. The lower part of the preheating roasting device is provided with a combustion station, combustible gas such as natural gas, coke oven gas and the like is mixed and combusted with air, and the internal temperature of the preheating roasting device is heated to 600-700 ℃. The high-carbon stone coal fine ore is preheated in the process of flowing through the preheating roasting device. The retention time is 20 s-30 s, and the absorbed water in the material can be removed in the process. The ore powder is heated to 400-500 ℃ after preheating and roasting, and is subjected to decarburization and roasting operation.
3. And (3) decarburization roasting process: the preheated high-carbon stone coal is fed into the second section of the fluid microwave roasting system, namely the decarburization roasting operation, and the material change of the decarburization roasting device is shown in figure 3. The electric heating jacket on the outer wall of the decarburization roasting device controls the temperature in the furnace chamber to be 600-650 ℃. Air is introduced into the bottom of the decarburization roasting device, and the roasting air quantity (4 m) can be accurately adjusted according to the requirement 3 /h～6m 3 H). In the process, most of the carbon in the raw ore is removed by combustion, and the vanadium in the raw ore is enriched in the ash. The suspended material in the furnace is heated uniformly, and sintering caused by local high temperature can be prevented. The process can also remove the components of the adsorption water, partial crystal water and volatile matters in the raw ore. After the fine ore reacts in the equipment for 30-50 min, the decarburized product with uniform and stable properties is fed into the next section of fluid microwave roasting operation.
4. Fluid microwave roasting process: the decarbonized product is directly fed into the third section of the fluid microwave roasting system, namely the fluid microwave roasting operation, and the material change of the fluid microwave roasting device is shown in figure 4. The microwave applicator on the outer wall of the fluid microwave roasting apparatus can generate a microwave field to generate electromagnetic energy to sharply heat the material particles. Introducing air and O into the bottom of the fluid microwave roasting device 2 The roasting gas amount and the oxygen concentration can be regulated and controlled according to the variation of the feeding property. By regulating and controlling the total gas quantity (8 m) 3 /h～12m 3 H) and electromagnetic heater power (35 kW-50 kW), the temperature in the equipment can be controlled to 850-900 ℃. After the temperature of the material rises, the mica and illite minerals are subjected to dehydroxylation reaction, the silicon-oxygen octahedral structure where the vanadium ions in the crystal lattice are located is unstable, and the constraint of the mineral crystal lattice on the vanadium ions is greatly weakened. Is composed ofEnsuring that the vanadium-containing mineral crystal lattice is fully forced to be damaged, and the reaction time of the materials in the equipment is 50-80 min.
5. An ultrasonic microbubble acid leaching process: vanadium in the roasted product exists in a +4 and +5 valence form and is easy to dissolve in acid liquor. The ultrasonic wave acts on the leaching agent to generate strong cavitation, and a large amount of micro bubbles are generated in the solution. The bubbles vibrate, grow or are broken along with the vibration of the surrounding solution, and high temperature and high pressure are generated at the bubble breakage part and between the two phases, so that the full contact of a liquid-solid interface is effectively promoted, and the dissolution of vanadium is enhanced. Thereby reducing the dosage of the leaching agent, shortening the leaching time and improving the vanadium leaching rate. The material change of the ultrasonic microbubble acid leaching device is shown in figure 5, the power of an ultrasonic generator is 8 kW-15 kW in the leaching process, concentrated sulfuric acid is adopted as a leaching agent, the liquid-solid ratio is 3:1-2:1, the leaching temperature is 80-90 ℃, the dosage of the leaching agent is 8% -20%, the leaching time is 1 h-1.5 h, a high vanadium solution and leaching slag are obtained, the leaching rate of vanadium in the high-carbon stone coal can reach 80% -90% according to the high vanadium solution, and after vanadium is extracted from the high vanadium solution, the obtained leaching agent can be recycled as the leaching agent.
The specific embodiment is as follows:
example 1
In this example, the raw ore of high-carbon stone coal is taken from the place in Hubei, raw ore V 2 O 5 1.09% of C, 12.82% of TFe, 2.36% of SiO 2 The content is 49.62 percent, and quartz and vanadium-containing phlogopite are main constituent minerals. The examples were developed as follows:
(1) And (3) a crushing process: crushing the raw ore by a jaw crusher, and grinding the raw ore by an overflow ball mill to obtain a product with the granularity of-0.074 mm accounting for 92 percent and-0.045 mm accounting for 75 percent, thereby obtaining the ground high-carbon stone coal.
(2) Preheating and roasting: feeding the high-carbon stone coal powder ore into a preheating roasting device. The coke oven gas is used as fuel to burn, and the interior of the preheating roasting device is heated to 700 ℃. The material flows through the device and is heated to 450 ℃ by heat conduction, convection and radiation effects, thus obtaining the preheated high-carbon stone coal.
(3) And (3) decarburization roasting process: the preheated high-carbon stone coal is fed into the decarburization roasting operation, and the device is as shown in figure 3Shown in the figure. The temperature in the furnace chamber is controlled at 650 ℃ by adjusting the electric heating device, and the air flow is 5m 3 H is used as the reference value. The decarbonized product is reacted in the device for 40min and then fed into the fluid microwave roasting operation.
(4) Fluid microwave roasting process: the decarbonized product is fed into a fluid microwave roasting device, and the temperature in a furnace body is controlled to be 890 ℃ by adjusting an electromagnetic heater and introducing air quantity. The power of the electromagnetic heater is 45.5kW, and 10.5m of electromagnetic heater is introduced into the furnace body 3 H mixed gas of air and O 2 The volume ratio of (1) is 3:1, and the reaction is continued for 60min. The roasted product is directly fed into the ultrasonic microbubble acid leaching operation.
(5) An ultrasonic microbubble acid leaching process: adding the roasted product into a concentrated sulfuric acid leaching agent accounting for 13% of the roasted product by mass, wherein the power of an ultrasonic generator in the leaching process is 15kW, and the liquid-solid ratio (concentrated sulfuric acid + water): the roasting product is 2mL. The leaching rate of the finally obtained vanadium is 85.79%.
Example 2
In this example, the raw ore of high-carbon stone coal is taken from some place in Shaanxi, V in raw ore 2 O 5 0.83% of C, 18.16% of TFe, 3.54% of SiO 2 61.87%, quartz and vanadium-containing illite and vanadium-containing sericite are the main minerals, wherein the vanadium mineral is mainly represented in the illite and the sericite in a similar manner, and the content of the vanadium mineral is 88%. The example fluid microwave roasting vanadium extraction process was developed as follows:
(1) And (3) crushing: after the raw ore is crushed by a jaw crusher and ground by a dry semi-autogenous mill, the granularity of the product reaches-0.074 mm and accounts for 81 percent, and-0.045 mm and accounts for 72 percent, and the ground high-carbon stone coal is obtained.
(2) Preheating and roasting: feeding the high-carbon stone coal powder ore into a preheating roasting device. Natural gas was used as a fuel to heat the interior of the roasting apparatus to 680 ℃. The material flows through the device and is heated to 425 ℃ by heat conduction, convection and radiation effects, thus obtaining the preheated high-carbon stone coal.
(3) And (3) decarburization roasting process: the preheated high-carbon stone coal is subjected to decarburization roasting, and the apparatus is shown in FIG. 3. The temperature in the furnace chamber is controlled at 650 ℃ by adjusting the electric heating device,air flow 5.5m 3 H is used as the reference value. The decarbonized product is reacted for 45min in the device and then fed into microwave roasting operation.
(4) Fluid microwave roasting process: the decarbonized product is fed into a fluid microwave roasting device, and the temperature in the furnace body is controlled to be 900 ℃ by adjusting an electromagnetic heater and introducing air quantity. The power of the electromagnetic heater is 50kW, and 9m of electromagnetic heater is introduced into the furnace body 3 H mixed gas of air and O 2 The volume ratio of (1) was 5:1, and the reaction was continued for 75min.
(5) An ultrasonic microbubble acid leaching process: adding the roasted product into a concentrated sulfuric acid leaching agent accounting for 9% of the mass fraction of the roasted product, wherein the power of an ultrasonic generator in the leaching process is 9.5kW, and the liquid-solid ratio (concentrated sulfuric acid + water): the roasted product is 3mL and 1g, the leaching temperature is 85 ℃, and the leaching time is 1.5h. The leaching rate of the finally obtained vanadium is 84.03%.
Example 3
In this case, the raw ore of high-carbon stone coal is taken from some place in Gansu province, V in raw ore 2 O 5 0.99% of C, 21.26% of TFe, 3.54% of SiO 2 The content of 58.37% is quartz, illite and sericite which are main mineral components, and vanadium is mainly contained in the illite and sericite, and the content of vanadium reaches 95.3%. The example fluid microwave roasting vanadium extraction process was developed as follows:
(1) And (3) crushing: after the raw ore is crushed by a cone crusher and ground by a semi-autogenous mill, the granularity reaches-0.074 mm accounting for 85 percent and-0.045 mm accounting for 79 percent, and the ground high-carbon stone coal is obtained.
(2) Preheating and roasting: natural gas was used as a fuel to heat the interior of the apparatus to 678 ℃. The material flows through the device and is heated to 432 ℃ by heat conduction, convection and radiation effects, so as to obtain the preheated high-carbon stone coal.
(3) And (3) decarburization roasting process: the preheated high-carbon stone coal is fed into the decarburization roasting operation, and the device is shown in figure 3. The temperature in the furnace chamber is controlled at 632 ℃ by adjusting the electric heating device, and the air volume is 5.8m 3 H is the ratio of the total weight of the catalyst to the total weight of the catalyst. The decarbonized product is reacted for 35min in the device and then fed into microwave roasting operation.
(4) Fluid microwave roasting process: the decarbonized product is fed into a fluid microwave roasting device to adjust an electromagnetic heaterAnd controlling the temperature in the furnace body to be 889 ℃ by introducing gas. The power of the electromagnetic heater is 42kW, and 10m of electromagnetic heater is introduced into the furnace body 3 H mixed gas of air and O 2 The volume ratio of (1) is 5:2, and the reaction is continued for 50min.
(5) An ultrasonic microbubble acid leaching process: directly feeding the roasted product into ultrasonic microbubble acid leaching operation, adding the roasted product into sulfuric acid which accounts for 11% of the mass fraction of the roasted product, wherein the power of an ultrasonic generator is 10kW in the leaching process, and the ratio of concentrated sulfuric acid to water (concentrated sulfuric acid plus water): the roasted product is 2mL. The leaching rate of the finally obtained vanadium is 88.79%.
Example 4
In this example, the raw ore of high-carbon stone coal is obtained from one place in Gansu province, V in the raw ore 2 O 5 0.99% of C, 21.26% of TFe, 3.54% of SiO 2 The content of 58.37% is quartz, illite and sericite which are main mineral components, and vanadium is mainly contained in the illite and sericite, and the content of vanadium reaches 95.3%. The example fluid microwave roasting vanadium extraction process was developed as follows:
(1) And (3) crushing: after the raw ore is crushed by a cone crusher and ground by a semi-autogenous mill, the granularity reaches-0.074 mm accounting for 85 percent and-0.045 mm accounting for 79 percent, and the ground high-carbon stone coal is obtained.
(2) Preheating and roasting: natural gas was used as a fuel to heat the interior of the apparatus to 678 ℃. The material flows through the device and is heated to 432 ℃ by heat conduction, convection and radiation effects, so as to obtain the preheated high-carbon stone coal.
(3) And (3) decarburization roasting process: the preheated high-carbon stone coal is subjected to decarburization roasting, and the apparatus is shown in FIG. 3. The temperature in the furnace chamber is controlled at 632 ℃ by adjusting the electric heating device, and the air volume is 5.8m 3 H is used as the reference value. The decarbonized product is reacted for 35min in the device and then fed into microwave roasting operation.
(4) Fluid microwave roasting process: the decarbonized product is fed into a fluid microwave roasting device, and the temperature in a furnace body is controlled to be 889 ℃ by adjusting an electromagnetic heater and introducing gas quantity. The power of the electromagnetic heater is 42kW, and 10m of electromagnetic heater is introduced into the furnace body 3 H mixed gas of air and O 2 The volume ratio of (3) is 5:2, and the reaction is continued for 50min.
(5) An ultrasonic microbubble acid leaching process: directly feeding the roasted product into ultrasonic microbubble acid leaching operation, adding concentrated sulfuric acid which accounts for 11% of the roasted product in mass percent, wherein the power of an ultrasonic generator is 10kW in the leaching process, and the ratio of (concentrated sulfuric acid + water) is as follows: the roasted product is 2mL. The leaching rate of the finally obtained vanadium is 89.79 percent.
Example 5
The same as example 1, except that the decarburization baking temperature was 615 ℃ and the amount of air fed into the furnace was 5.2m 3 H, reacting for 45min; the total gas amount of the fluid microwave roasting is 8.5m 3 The microwave power is 43kW, the microwave roasting temperature is 850 ℃, and other conditions are kept unchanged. Finally, the leaching rate of vanadium is 85.70%.
Example 6
The same as example 2, except that the decarburization baking temperature was 643 ℃ and the amount of air fed into the furnace was 5.7m 3 Reacting for 50min per hour; the total gas amount of fluid microwave roasting is 10.3m 3 The microwave power is 48kW, the microwave roasting temperature is 890 ℃, and other conditions are kept unchanged. Finally, the leaching rate of vanadium is 83.30%.
Example 7
The same as example 3, except that the decarburization roasting temperature was 635 ℃; the total gas amount of fluid microwave roasting is 10.3m 3 The microwave power is 38.8kW, the microwave roasting temperature is 870.4 ℃, and other conditions are kept unchanged. Finally, the leaching rate of vanadium is 86.43%.
Example 8
The difference from example 4 is that the total gas amount for microwave roasting of the fluid is 11.6 3 The microwave power is 44kW, the microwave roasting temperature is 865 ℃, and other conditions are kept unchanged. Finally, the leaching rate of vanadium is 86.91%.
Comparative example 1
The difference from example 1 is that there is no external field microwave heating during the fluid microwave roasting process, only the common electric heating mode is used, and other experimental conditions are the same. The leaching rate of the finally obtained vanadium is only 77.52 percent.
Comparative example 2
The same experiment as in example 1 was conducted except that the preliminary decarburization process was not conducted. The fired sample was heavily sintered to form a large number of agglomerates. The leaching rate of the finally obtained vanadium is only 71.25%.
Comparative example 3
The difference from example 1 is that this example is carried out by conventional leaching without ultrasonic action and cavitation bubbles in the leaching tank, and only ordinary agitation leaching. The other experimental conditions were the same. The leaching rate of the finally obtained vanadium is only 78.36 percent.
Claims (9)
1. The method for extracting vanadium from high-carbon stone coal by step-by-step microwave roasting-ultrasonic microbubble acid leaching is characterized by comprising the following steps of: crushing and grinding the high-carbon stone coal to obtain ground high-carbon stone coal; preheating and roasting the high-carbon stone coal which is finely ground, decarburizing and roasting, then placing the high-carbon stone coal in a microwave environment for fluid microwave roasting, and carrying out ultrasonic microbubble acid leaching on the obtained roasted product.
2. The method for extracting vanadium from high-carbon stone coal by step-by-step microwave roasting-ultrasonic microbubble acid leaching is characterized by comprising the following steps of:
1. and (3) crushing:
the crushing process comprises two working procedures of crushing and grinding; specifically, high-carbon stone coal is crushed and ground until the grain size is-0.045 mm and the grain size is 65-80%, and ground high-carbon stone coal is obtained;
2. preheating and roasting:
carrying out preheating roasting operation on the ground high-carbon stone coal, and heating the ground high-carbon stone coal to 400-500 ℃ to obtain preheated high-carbon stone coal;
3. and (3) decarburization roasting process:
the preheated high-carbon stone coal is decarbonized and roasted, air is introduced in the decarbonization and roasting process, and the roasting air quantity is adjusted to be 4m 3 /h～6m 3 The temperature is controlled between 600 ℃ and 650 ℃, and after the reaction is carried out for 30min to 50min, the decarburized product with uniform and stable properties is obtained;
4. fluid microwave roasting process:
performing fluid microwave roasting on the decarbonized product, and introducing air and O in the fluid microwave roasting process 2 Regulating and controlling roasting gas quantity and O 2 Concentration; by regulating the total gas amount to 8m 3 /h～12m 3 The reaction time/h and the microwave power are 35kW to 50kW, the fluid microwave roasting temperature is controlled to 850 ℃ to 900 ℃, and the reaction time is 50min to 80min, so that a roasted product is obtained;
5. an ultrasonic microbubble acid leaching process:
mixing the roasted product and the leaching solution to carry out an ultrasonic microbubble acid leaching process, wherein in the ultrasonic microbubble acid leaching process, the ultrasonic power is 8kW to 15kW, the leaching agent adopts concentrated sulfuric acid, the leaching temperature is 80 ℃ to 90 ℃, and the leaching time is 1h to 1.5h, so that a high-vanadium solution and leaching slag with low vanadium content are obtained.
3. The method for extracting vanadium by microwave roasting-ultrasonic microbubble acid leaching in steps of the high-carbon stone coal as claimed in claim 2, wherein in the step one, the particle size of the high-carbon stone coal is 20mm to 400mm; the particle size after crushing is 1 mm-12 mm.
4. The method for extracting vanadium from high-carbon stone coal by microwave roasting and ultrasonic microbubble acid leaching in steps as claimed in claim 2, wherein in the first step, a jaw crusher is used for crushing; the ore grinding adopts one of a semi-autogenous mill, an overflow ball mill or a stirring mill.
5. The method for extracting vanadium by microwave roasting and ultrasonic microbubble acid leaching in steps of high-carbon stone coal as claimed in claim 2, wherein in the second step, preheating roasting is carried out, the preheating roasting temperature is 600-700 ℃, and the residence time of the preheating roasting is 20-30 s.
6. The method for extracting vanadium by microwave roasting-ultrasonic microbubble acid leaching in steps of claim 2, wherein in the third step, air is introduced from the lower part of the decarburization roasting equipment, and the air flows from bottom to top.
7. The method for extracting vanadium from high-carbon stone coal by microwave roasting in steps and ultrasonic microbubble acid leaching in steps as claimed in claim 2, wherein in the fourth step, the ratio by volume of air: o is 2 ＝(3-6):(1～2)。
8. The method for extracting vanadium by high-carbon stone coal step-by-step microwave roasting-ultrasonic microbubble acid leaching according to claim 2, wherein in the fifth step, concentrated sulfuric acid accounts for 8% -20% of the roasted product by mass percent, and the ratio of (concentrated sulfuric acid + water) is as follows according to liquid-solid ratio: the roasted product was (2-3) mL:1g.
9. The method for extracting vanadium from high-carbon stone coal by microwave roasting-ultrasonic microbubble acid leaching in steps according to any one of claims 1 to 8, wherein the leaching rate of vanadium in the high-carbon stone coal can reach 80 to 90 percent.
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