Method for preparing ferrovanadium from stone coal vanadium ore

Abstract

The invention provides a method for preparing ferrovanadium from stone coal navajoite, which belongs to the technical field of metal mineral smelting and comprises the following steps: crushing and grinding stone coal navajoite, and drying to obtain dried stone coal navajoite powder; mixing the dried stone coal vanadium ore powder with an iron trapping agent, a reducing agent and a slagging material to prepare pellets; smelting the pellets at high temperature to obtain molten slag liquid; molten liquid obtained through molten slag-liquid separation is cooled to obtain vanadium-iron alloy, and obtained molten slag is quenched and tempered to obtain rock wool. The method for preparing the ferrovanadium alloy from the stone coal vanadium ore is simple in process, economical, efficient, environmentally friendly and high in vanadium recovery rate.

Description

Technical Field

[0001] The present invention relates to the technical field of metal mineral smelting, and in particular to a method for preparing ferrovanadium alloy from stone coal vanadium ore. Background Art

[0002] Vanadium is an important strategic metal that has been widely used in various fields such as steel, defense industry, catalysts, aerospace, automobiles, batteries, etc.

[0003] At present, there are two major types of mineral resources for extracting vanadium, one is vanadium-titanium magnetite, and the other is vanadium-containing stone coal (also known as coal gangue), namely stone coal vanadium ore.

[0004] Numerous studies have revealed that vanadium in stone coal vanadium ore can also form independent vanadium minerals such as vanadium mica, titanovanadium garnet, grossular vanadium garnet, metavanadite, and titanite. These single minerals theoretically contain high vanadium contents and are the most concentrated mineral components in stone coal vanadium ore. However, based on the mineral crystal structure, strictly speaking, independent vanadium minerals should also be considered as vanadium in an isomorphous form. This stability also increases the difficulty of extracting vanadium from stone coal vanadium ore.

[0005] Currently, common methods for vanadium extraction include roasting-leaching and direct acid leaching. The main problem with the chlorination roasting process is its low recovery rate of only 40-60%. The chlorination roasting process also produces harmful gases such as Cl2 and HCl, which pose a significant environmental risk. Direct acid leaching also presents challenges such as high temperature, high acidity, and low vanadium leaching rates. Furthermore, wet enrichment increases reagent consumption and costs. Furthermore, the large amounts of waste gas, wastewater, and waste residue generated during the leaching process also contribute to increased environmental pollution.

[0006] Therefore, there is an urgent need for a method for preparing ferrovanadium alloy from stone coal vanadium ore that is environmentally friendly and has a high vanadium recovery rate. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a method for preparing ferrovanadium alloy from stone coal vanadium ore with simple process, high economic efficiency, environmental friendliness and high vanadium recovery rate.

[0008] To solve the above technical problems, the present invention provides a method for preparing ferrovanadium alloy from stone coal vanadium ore, comprising the following steps:

[0009] The stone coal vanadium ore is crushed, ground and then dried to obtain dry stone coal vanadium ore powder;

[0010] Mixing dry stone coal vanadium ore powder with an iron collector, a reducing agent, and slag-forming materials to form pellets;

[0011] The pellets are smelted at high temperature to obtain molten slag liquid;

[0012] The melt obtained by separation of molten slag and liquid is cooled to obtain vanadium-ferroalloy, and the obtained slag is tempered to obtain rock wool.

[0013] Furthermore, the particle size of the stone coal vanadium ore powder obtained after grinding the stone coal vanadium ore is below 200 meshes.

[0014] Furthermore, the stone coal vanadium ore powder is dried in a drying oven at a drying temperature of 100-150° C. and a drying time of 1-3 hours.

[0015] Furthermore, the iron collector is iron ore powder, the reducing agent is blue coke, and the slag-making material is a mixture of quicklime, light-burned magnesium oxide powder and aluminum oxide powder.

[0016] Furthermore, the iron ore concentrate powder contains 60-70% TFe, less than 0.1% MFe, and less than 27.78% FeO; the semi-coke contains 68-72% fixed carbon and 6-9% ash; the quicklime contains 90-93% CaO, the light-burned magnesium oxide powder contains 78-82% MgO, and the alumina powder is alumina for industrial electrolytic aluminum, with Al2O3>99%.

[0017] Furthermore, the amount of the iron ore concentrate powder added is 6-8% of the mass of the dry stone coal vanadium ore powder, the amount of the lignite added is determined according to the carbon content in the stone coal vanadium ore, and the amount of the lignite added is controlled to be 0-0.68% of the mass of the dry stone coal vanadium ore powder, the amount of the quicklime added is 32-40% of the mass of the dry stone coal vanadium ore powder, the amount of the light-burned magnesium oxide powder added is 11-15% of the mass of the dry stone coal vanadium ore powder, and the amount of the alumina powder added is 11-15% of the mass of the dry stone coal vanadium ore powder.

[0018] Furthermore, the high-temperature smelting of the pellets is carried out in an electric arc furnace at a smelting temperature of 1500-1600° C. and a smelting holding time of 0.5-2 hours.

[0019] Furthermore, the molten slag-liquid separation is to pour the molten slag-liquid into a conical mold, form an upper layer of slag and a lower layer of melt by natural sedimentation, and pour out the upper layer of slag to obtain the lower layer of melt.

[0020] Furthermore, after being poured out, the molten slag directly enters the rock wool production line through the slag bag and is re-tempered to produce rock wool.

[0021] Furthermore, the molten metal is naturally air-cooled at room temperature to obtain ferrovanadium alloy, and the obtained ferrovanadium alloy can be further separated from the glassy slag on the surface of the ferrovanadium alloy by manual stripping.

[0022] The present invention provides a method for preparing vanadium-iron alloy from stone coal vanadium ore. Iron concentrate powder is added to the stone coal vanadium ore as an iron capture agent, which can better reduce the iron and vanadium ions in the stone coal vanadium ore into iron and vanadium to form an iron-vanadium alloy.

[0023] The present invention also provides a method for preparing ferrovanadium from stone coal vanadium ore. A slagging agent is added to the stone coal vanadium ore. The slagging agent controls the pH and fluidity of the slag, facilitating the release of vanadium from the stone coal vanadium ore and reducing interference from gangue components such as silicon and aluminum. The released vanadium reacts with a reducing agent to produce elemental V, which is then captured by an iron capture agent to form a ferrovanadium alloy. Furthermore, the slagging agent can control the viscosity of the slag to a low level, thereby improving the fluidity of the slag. This further increases the V capture rate during the V capture process, ultimately improving the separation efficiency of the resulting slag from gold and increasing the vanadium enrichment rate in the stone coal vanadium ore, reaching a 10-fold vanadium enrichment rate in the stone coal vanadium ore.

[0024] The present invention also provides a method for preparing vanadium-iron alloy from stone coal-vanadium ore. This method uses a slagging agent to stably encapsulate impurity elements in the stone coal-vanadium ore, and introduces an iron scavenger to achieve efficient vanadium enrichment, thereby avoiding the use of strong acids and chlorinating agents. This significantly reduces wastewater, waste gas, and solid waste emissions, making it more environmentally friendly. Compared to traditional stone coal roasting-acid leaching or chlorination vanadium extraction processes, the method provided by the present invention avoids problems such as difficult acid treatment, heavy chlorine gas emission pollution, low vanadium recovery rate, and high metal residue in tailings, significantly improving resource utilization and production safety.

[0025] In addition, the present invention provides a method for preparing vanadium-iron alloy from stone coal vanadium ore, which has a simple process flow, avoids the cumbersome process of traditional vanadium extraction process, realizes an efficient and clean vanadium extraction process, avoids the consumption of acid and the generation of a large amount of wastewater in the traditional vanadium extraction process, and is environmentally friendly and efficient. Moreover, the present invention directly further produces rock wool from the hot slag obtained by separating the final molten slag liquid, which can avoid environmental pollution caused by the accumulation of slag and enhance the value of the hot slag. At the same time, the separated hot slag is quickly made into rock wool for exterior wall insulation, which can also fully utilize the thermal energy of the hot slag, saving the heat consumption of the rock wool preparation step, having high economic benefits, and worthy of promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A flow chart of a method for preparing ferrovanadium alloy from stone coal vanadium ore provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] See also Figure 1 The present invention provides a method for preparing ferrovanadium alloy from stone coal vanadium ore, comprising the following steps:

[0028] Step 1) crushing and grinding the stone coal vanadium ore and drying it to obtain dry stone coal vanadium ore powder.

[0029] Among them, in order to facilitate the full mixing of the stone coal vanadium ore and the subsequently added raw materials and increase the contact area, the stone coal vanadium ore is crushed and then ground to obtain stone coal vanadium ore powder with a particle size of less than 200 mesh.

[0030] Furthermore, in order to facilitate the smelting reaction after mixing the stone coal vanadium ore powder with subsequent raw materials, the ground stone coal vanadium ore powder is placed in a drying oven for drying at a temperature of 100-150° C. for 1-3 hours to obtain dry stone coal vanadium ore powder.

[0031] Step 2) The dried stone coal vanadium ore powder is mixed with an iron collector, a reducing agent, and slag-forming materials in a certain proportion to form pellets.

[0032] Among them, the iron collector is iron concentrate powder, the reducing agent is lignite, and the slag-making material is a mixture of quicklime, light-burned magnesium oxide powder and aluminum oxide powder.

[0033] The iron ore concentrate contains 60-70% TFe and less than 0.1% MFe. Furthermore, the iron oxide content in the iron ore concentrate should not be too high, as this will increase the volatile matter in the system. This volatile matter will remove some vanadium from the stone coal vanadium ore during volatilization, thus affecting the vanadium enrichment rate. Therefore, the FeO content is controlled below 27.78%.

[0034] The present invention uses iron concentrate powder as an iron capture agent added to the stone coal vanadium ore, which can better reduce the iron and vanadium ions in the stone coal vanadium ore into iron and vanadium to form an iron-vanadium alloy in the subsequent smelting reaction.

[0035] As a specific embodiment of the present invention, in order to effectively reduce the iron and vanadium ions in the stone coal vanadium ore into iron and vanadium to form an iron-vanadium alloy in the subsequent smelting reaction, the addition amount of iron ore concentrate powder is controlled to 6-8% of the mass of the dry stone coal vanadium ore powder.

[0036] Among them, the fixed carbon content in lignite is 68-72%, and the ash content is 6-9%.

[0037] The amount of blue coke added is determined by the carbon content in the stone coal vanadium ore. The amount of blue coke added is usually controlled to be 0-0.68% of the mass of the dry stone coal vanadium ore powder.

[0038] The quicklime in the slagging agent is quicklime with a CaO content of 90-93%, the MgO content in the light-burned magnesium oxide powder is 78-82%, and the alumina powder is alumina for industrial electrolytic aluminum, with Al2O3>99%.

[0039] Among them, when the slag-forming agent is added to the stone coal vanadium ore, its quicklime, lightly burned magnesium oxide powder and aluminum oxide powder can form a slag system with the silicon dioxide in the stone coal vanadium ore, lowering the melting point of the formed slag system, improving the fluidity of the slag, making it easier to release vanadium from the stone coal vanadium ore, and reducing the interference of gangue components such as silicon and aluminum.

[0040] To precisely control the viscosity of the resulting slag, thereby facilitating alloy formation and smoothing, the viscosity and melting point of the resulting slag are altered by adjusting the content of the slag-forming agent, while also allowing the resulting slag composition to vary within the rock wool content range. The present invention controls the addition of quicklime to 32-40% of the mass of the dry stone coal-vanadium ore powder, the addition of light-burned magnesium oxide powder to 11-15% of the mass of the dry stone coal-vanadium ore powder, and the addition of alumina powder to 11-15% of the mass of the dry stone coal-vanadium ore powder.

[0041] The present invention uses a slag-forming agent to control the pH and fluidity of the slag obtained through smelting, facilitating the release of vanadium from the stone coal vanadium ore and reducing interference from gangue components such as silicon and aluminum. The released vanadium reacts with a reducing agent to produce elemental V, which is then captured by an iron capture agent to form a ferrovanadium alloy. Furthermore, the slag-forming agent can control the viscosity of the slag at a low level, thereby improving the fluidity of the slag. This further increases the V capture rate during the V capture process, ultimately enhancing the separation efficiency of the resulting slag from gold and increasing the vanadium enrichment rate in the stone coal vanadium ore, reaching a vanadium enrichment rate of up to 10 times.

[0042] Step 3) The pellets are smelted at high temperature to obtain molten slag liquid.

[0043] Specifically, the pellets obtained in step 2) are placed in an electric arc furnace for high-temperature smelting to obtain molten slag.

[0044] During pellet smelting, if the smelting temperature is too low, the reduction reaction of the pellets will not proceed completely, resulting in poor fluidity of the resulting molten metal and slag phases, which will affect the vanadium enrichment rate. However, if the smelting temperature is too high, it will waste resources and increase production costs. Therefore, as a specific embodiment of the present invention, the smelting temperature of the pellets in the electric arc furnace is controlled at 1500-1600°C.

[0045] Furthermore, during pellet smelting, if the smelting time is too short, the metallic vanadium in the reaction system cannot fully migrate to the metal phase, which will also affect the vanadium enrichment rate. However, if the smelting time is too long, production efficiency will be reduced. Therefore, as a specific embodiment of the present invention, the pellet smelting time in the electric arc furnace is controlled to 0.5-2 hours.

[0046] Step 4) The melt obtained by separation of molten slag and liquid is cooled to obtain vanadium-ferroalloy, and the obtained slag is tempered to obtain rock wool.

[0047] In one embodiment of the present invention, when separating the molten slag, the smelted molten slag is poured into a conical mold. Due to the different densities and weights of the slag and the alloy melt, slag forms an upper layer and an alloy melt forms a lower layer. The slag in the upper layer is poured out to obtain the alloy melt in the lower layer. The resulting slag mainly contains 20.18% Al2O3, 32.6% CaO, 41.25% SiO2, and 3.04% MgO.

[0048] In one embodiment of the present invention, the slag is poured directly into the rock wool production line via a slag bag for re-tempering and producing rock wool. Furthermore, to avoid excessive heat loss from the slag, the poured slag should be quickly transferred to the slag bag for rock wool production.

[0049] The present invention directly converts the hot slag obtained by separating the molten slag liquid into rock wool, thereby avoiding environmental pollution caused by the accumulation of slag and increasing the value of the hot slag. Simultaneously, the separated hot slag is quickly converted into rock wool for exterior wall insulation, fully utilizing the thermal energy of the hot slag and reducing the heat consumption of the rock wool preparation step. This not only saves resources but also has high economic benefits and is worthy of widespread application.

[0050] As a specific embodiment of the present invention, after the melt obtained by molten slag separation is naturally cooled at room temperature to obtain ferrovanadium alloy, since a small amount of slag that has not been completely separated still exists in the melt, a layer of glassy solidified slag will be formed on the surface of the ferrovanadium alloy obtained by cooling the melt. The glassy slag on the surface of the ferrovanadium alloy can be further separated by manual stripping, thereby obtaining a ferrovanadium alloy with higher purity. The obtained ferrovanadium alloy mainly comprises Fe78.35%, Si11.35% and V4.09%.

[0051] The present invention can stably encapsulate impurity elements in stone coal vanadium ore through a slag-forming agent, and can achieve efficient enrichment of vanadium by introducing an iron capture agent, thereby avoiding the use of strong acid and chlorinating agent, and can significantly reduce the emission of wastewater, waste gas and solid waste. Not only is the process simple and efficient, but the vanadium extraction is clean and environmentally friendly, greatly improving resource utilization and production safety.

[0052] The following examples illustrate the method for preparing ferrovanadium alloy from stone coal vanadium ore provided by the present invention.

[0053] Example 1

[0054] (1) Crushing the stone coal vanadium ore, grinding it through a 100-mesh sieve to obtain stone coal vanadium ore powder, and then drying the stone coal vanadium ore powder in a drying oven at 100-150° C. for 1-3 hours to obtain dry stone coal vanadium ore powder.

[0055] (2) Take 15 kg of dry stone coal vanadium ore powder, 1.21 kg of iron ore concentrate powder, and 15 kg of dolomite, and try to add a small amount of 0.48 kg of blue carbon, mix them evenly, press them into pellets, and dry them for later use.

[0056] (3) The pellets are reduced at 1500-1600°C for 2.5 hours, the upper layer of hot slag is transferred to the rock wool production line, the alloy and a small amount of slag at the bottom are poured into a mold and naturally cooled, and the glassy slag on the surface of the alloy is peeled off to obtain vanadium-iron alloy.

[0057] The obtained ferrovanadium alloy was tested, and the total recovery rate of vanadium was calculated to be about 94.41%, and the total recovery rate of iron was 92.85%.

[0058] Example 2

[0059] (1) Crushing the stone coal vanadium ore, grinding it through a 200-mesh sieve to obtain stone coal vanadium ore powder, and then drying the stone coal vanadium ore powder in a drying oven at 100-150° C. for 1-3 hours to obtain dry stone coal vanadium ore powder.

[0060] (2) Take 15 kg of dry stone coal vanadium ore powder, 1.21 kg of iron ore concentrate powder, 6 kg of quicklime powder, 2 kg of light-burned magnesium powder, and 2 kg of alumina powder, mix them evenly, press them into pellets, and dry them for later use.

[0061] (3) The pellets are reduced at 1500-1600°C for 3 hours, the upper layer of hot slag is transferred to the rock wool equipment production line, and the alloy and a small amount of slag at the bottom are poured into a mold and naturally cooled to obtain vanadium-iron alloy.

[0062] The vanadium-ferroalloy was tested and the total recovery rate of vanadium was calculated to be about 96.43%, and the total recovery rate of iron was 95.1%.

[0063] Example 3

[0064] (1) Crushing the stone coal vanadium ore, grinding it through a 200-mesh sieve to obtain stone coal vanadium ore powder, and then drying the stone coal vanadium ore powder in a drying oven at 100-150° C. for 1-3 hours to obtain dry stone coal vanadium ore powder.

[0065] (2) Take 72 kg of dry stone coal vanadium ore powder, 4.93 kg of iron ore concentrate powder, 22.81 kg of quicklime powder, 9.77 kg of light-burned magnesium powder, 9.77 kg of alumina powder, and add a small amount of 0.49 kg of blue charcoal, mix well, press into pellets, and dry for later use.

[0066] (3) The pellets are reduced at 1500-1600°C for 3.5 hours, the upper layer of hot slag is transferred to the rock wool production line, and the alloy and a small amount of slag at the bottom are poured into a mold and naturally cooled to obtain vanadium-ferroalloy.

[0067] The vanadium-ferroalloy was tested and the total recovery rate of vanadium was calculated to be about 96.43%, and the total recovery rate of iron was 97.24%.

[0068] The total vanadium and iron recovery data from Examples 1-3 demonstrate that the method for preparing ferrovanadium from stone coal vanadium ore provided by the present invention, by adding iron concentrate powder to the stone coal vanadium ore, effectively captures vanadium from the stone coal to form the ferrovanadium alloy. Furthermore, the addition of a slag-forming agent facilitates the separation of the molten slag from the alloy melt. Furthermore, the vanadium recovery process is environmentally friendly and more efficient than conventional processes, significantly impacting vanadium extraction from stone coal vanadium ore.

[0069] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for preparing ferrovanadium alloy from stone coal vanadium ore, characterized in that: The steps include: The stone coal vanadium ore is crushed, ground and then dried to obtain dry stone coal vanadium ore powder; Mixing dry stone coal vanadium ore powder with an iron collector, a reducing agent, and slag-forming materials to form pellets; The pellets are smelted at high temperature to obtain molten slag liquid; The melt obtained by separation of molten slag and liquid is cooled to obtain vanadium-ferroalloy, and the obtained slag is tempered to obtain rock wool.

2. The method for preparing ferrovanadium alloy from stone coal vanadium ore according to claim 1, characterized in that: The particle size of the stone coal vanadium ore powder obtained after the stone coal vanadium ore is ground is below 200 meshes.

3. The method for preparing ferrovanadium alloy from stone coal vanadium ore according to claim 2, characterized in that: The stone coal vanadium ore powder is dried in a drying oven at a drying temperature of 100-150° C. for 1-3 hours.

4. The method for preparing ferrovanadium alloy from stone coal vanadium ore according to claim 1, characterized in that: The iron collector is iron ore powder, the reducing agent is blue coke, and the slag-making material is a mixture of quicklime, light-burned magnesium oxide powder and aluminum oxide powder.

5. The method for preparing ferrovanadium alloy from stone coal vanadium ore according to claim 4, characterized in that: The iron ore concentrate powder contains 60-70% TFe, less than 0.1% MFe, and less than 27.78% FeO. The semi-coke contains 68-72% fixed carbon and 6-9% ash. The quicklime contains 90-93% CaO, the light-burned magnesium oxide powder contains 78-82% MgO, and the alumina powder is alumina for industrial electrolytic aluminum, with Al2O3>99%.

6. The method for preparing ferrovanadium alloy from stone coal vanadium ore according to claim 5, characterized in that: The amount of the iron ore concentrate powder added is 6-8% of the mass of the dry stone coal vanadium ore powder, the amount of the blue coke added is determined according to the carbon content in the stone coal vanadium ore, and the amount of blue coke added is controlled to be 0-0.68% of the mass of the dry stone coal vanadium ore powder, the amount of the quicklime added is 32-40% of the mass of the dry stone coal vanadium ore powder, the amount of the light-burned magnesium oxide powder added is 11-15% of the mass of the dry stone coal vanadium ore powder, and the amount of the alumina powder added is 11-15% of the mass of the dry stone coal vanadium ore powder.

7. The method for preparing ferrovanadium alloy from stone coal vanadium ore according to claim 1, characterized in that: The pellets are smelted at high temperature in an electric arc furnace at a temperature of 1500-1600° C. for a holding time of 0.5-2 hours.

8. The method for preparing ferrovanadium alloy from stone coal vanadium ore according to claim 1, characterized in that: The molten slag liquid separation is to pour the molten slag liquid into a conical mold, form an upper layer of slag and a lower layer of melt by natural sedimentation, and pour out the upper layer of slag to obtain the lower layer of melt.

9. The method for preparing ferrovanadium alloy from stone coal vanadium ore according to claim 8, characterized in that: After being poured out, the molten slag directly enters the rock wool production line through the slag bag and is re-tempered to produce rock wool.

10. The method for preparing ferrovanadium alloy from stone coal vanadium ore according to claim 8, characterized in that: The molten metal is naturally air-cooled at room temperature to obtain ferrovanadium alloy. The obtained ferrovanadium alloy can be further separated from the glassy slag on the surface of the ferrovanadium alloy by manual stripping.

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