Gallium extraction process for vanadium extraction converter smoke dust

Abstract

The invention relates to the field of rare metal smelting and gallium extraction, in particular to a gallium extraction process for vanadium extraction converter smoke. According to the gallium extraction process, secondary resource ironmaking is free of carbon emission, meanwhile, gallium is directly recycled through alkali liquor, introduction of high-pollution organic matter is avoided, and meanwhile effective separation of gallium, iron and vanadium is achieved. The gallium extraction process is short, acid leaching and extraction processes are avoided, the process is shortened by at least half compared with other processes, organic components are prevented from being introduced into a gallium recovery system through extraction or ion exchange resin, and the impurity removal effect is good. According to the gallium extraction process, gallium can be finally extracted from gallium-containing secondary resources at a high recovery rate, the recovery rate reaches up to 95%, the extracted gallium meets the national standard of industrial gallium, meanwhile, generated by-products can be reused in a vanadium extraction and ironmaking system to obtain by-products with high economic value, excessive chlorine salt in the system can be collected regularly, and the method is suitable for industrial production. Because the chlorine salt is relatively pure, the chlorine salt can be directly reused in the first step of the gallium extraction process and the stage of mixing with the vanadium extraction converter smoke dust.

Description

Technical Field

[0001] The present invention relates to the fields of rare metal smelting and gallium extraction, and in particular to a process for extracting gallium from vanadium-extracting converter dust. Background Art

[0002] Gallium (Ga) is a rare metal with extremely low abundance in the Earth's crust and rarely occurs as a standalone mineral. It is primarily found in association with bauxite, lead-zinc ores, and coal, or in an isomorphous form within the mineral lattice. With the global energy transition and the rapid development of high-tech industries, the strategic importance of gallium has become increasingly prominent, and innovations in its extraction technology and resource recycling have become a global focus. Gallium is a core material in third-generation semiconductors (gallium nitride (GaN) and gallium arsenide (GaAs), solar cells (copper indium gallium selenide (CIGS), LED lighting, and 5G communication devices. 90% of the world's primary gallium is produced as a byproduct of bauxite smelting. However, major producers such as China and Germany face declining ore grades and rising extraction costs. Therefore, secondary resources have become a vital supplement.

[0003] Traditional gallium extraction relies on an acid / alkaline leaching-solvent extraction-electrolysis process, but this faces significant challenges: low selectivity and high environmental costs. Gallium has similar chemical properties to elements like aluminum, iron, and zinc, resulting in low separation efficiency, and traditional organic extractants are prone to pollution. Consequently, the international academic community is focusing on green extraction technologies such as bioleaching and ionic liquid extraction, aiming to reduce energy consumption and pollution, but these technologies are relatively costly.

[0004] The Panxi region is rich in valuable metals, and gallium is found alongside elements such as vanadium, iron, and titanium in Panxi ore mines. Since the 1970s, research into gallium extraction has primarily used vanadium tailings as a raw material. However, due to the complex composition of gallium in vanadium tailings, direct acid leaching has a low leaching rate, high acid consumption, and a large amount of difficult-to-use byproducts. Furthermore, the entire process is lengthy, so this route has not been put into industrial production. Summary of the Invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide a gallium extraction process for vanadium-extracting converter dust. The gallium extraction process provided by the present invention can extract gallium from gallium-containing secondary resources with a high recovery rate, and the extracted gallium meets the national standards for industrial gallium.

[0006] The present invention provides a gallium extraction process from vanadium extraction converter dust, comprising the following steps:

[0007] Calcining a mixed material of vanadium-extracting converter dust and chloride salt to obtain a slag-liquid mixture and gallium chloride volatiles, collecting the gallium chloride volatiles with alkaline solution, and then electrolyzing them to obtain metallic gallium;

[0008] The calcination temperature is 1000° C. to 1300° C., and the calcination vacuum degree is 1 Pa to 100 Pa.

[0009] The present invention first calcines a mixed molded material of vanadium-extracting converter dust and chloride salt. Specifically, the mixed molded material of vanadium-extracting converter dust and chloride salt described in the present invention is obtained by mixing and molding vanadium-extracting converter dust and chloride salt. More specifically, dried vanadium-extracting converter dust and chloride salt are mixed and then molded to obtain the mixed molded material of vanadium-extracting converter dust and chloride salt; the molding includes pelletizing or tableting. The mass amount of the chloride salt described in the present invention is 0.5 to 2 times the mass amount of the vanadium-extracting converter dust. The chloride salt described in the present invention is selected from one or more of sodium chloride, potassium chloride, and ammonium chloride. The diameter of the mixed molded material of vanadium-extracting converter dust and chloride salt described in the present invention is 2 cm to 12 cm.

[0010] The present invention calcines a mixed molded material of vanadium-extracting converter dust and chloride salt at a temperature of 1000° C. to 1300° C. and a vacuum degree of 1 Pa to 100 Pa. The calcination time depends on the amount of pellets added. Based on 1 ton of the mixed molded material of vanadium-extracting converter dust and chloride salt, the calcination time is 2 hours to 10 hours. The calcination of the present invention produces a slag-liquid mixture and gallium chloride volatiles. Specifically, during the calcination process, the mixed molding material of the vanadium extraction converter smoke and chloride salt melts, and the volatile metal elements first volatilize to the condensation area at a low temperature of 400°C to 600°C, while the non-volatilized materials form a slag layer and a molten liquid. The molten liquid includes pig iron, chloride salt and gallium. As the temperature rises to 800°C to 950°C, the chloride salt in the molten liquid decomposes and slowly releases chlorine gas, which reacts with the gallium in the molten liquid to form gallium chloride. The calcination temperature is controlled to be 1000°C to 1300°C to allow a large amount of gallium chloride to be produced. The gallium chloride is volatilized in a vacuum and enters the next gallium extraction process. The molten liquid after the reaction is mainly composed of pig iron. Therefore, the slag-liquid mixture obtained by calcination includes pig iron molten liquid and a slag layer. The slag layer can be used in the vanadium extraction process, and the pig iron molten liquid can be used as molten iron in the steelmaking process.

[0011] The vanadium-extracting converter dust of the present invention is specifically waste from the vanadium-titanium magnetite beneficiation process; the gallium content of the vanadium-extracting converter dust is 200 g / t to 500 g / t. More specifically, excluding the gallium content, the vanadium-extracting converter dust of the present invention also includes 85 wt% to 92 wt% Fe2O3, 1 wt% to 3 wt% SiO2, 1 wt% to 5 wt% ZnO, and less than 10 wt% of other impurities. That is, the remaining material after deducting the gallium content from the vanadium-extracting converter dust of the present invention includes 85 wt% to 92 wt% Fe2O3, 1 wt% to 3 wt% SiO2, 1 wt% to 5 wt% ZnO, and less than 10 wt% of other impurities; wherein the other impurities include Na2O, MgO, CaCO3, Al2O3, TiO2, V2O5, Cr2O3, PbO, CuO, NiO, chlorides, and sulfides. In certain embodiments of the present invention, the residual material after deducting the gallium content from the vanadium-extracting converter dust comprises 85 wt% to 92 wt% Fe2O3, 1 wt% to 3 wt% SiO2, 1 wt% to 5 wt% ZnO and less than 10 wt% of other impurities, wherein the other impurities include 0.5 wt% to 1.5 wt% Na2O, 0.5 wt% to 1.5 wt% MgO, 0.5 wt% to 2 wt% CaCO3, 0.1 wt% to 0.5wt% Al2O3, 0.1 wt% to 0.5 wt% TiO2, 0.5 wt% to 1.5 wt% V2O5, 0.1 wt% to 1 wt% Cr2O3, 0.5 wt% to 1.5 wt% PbO, 0.1 wt% to 0.5 wt% CuO, 0.1 wt% to 0.5 wt% NiO, 0.1 wt%~1.5 wt% chloride and 0.5wt%~1.5 wt% sulfide. The raw material of the vanadium-extracting converter dust of the present invention is unique and has a high gallium content. In the slag-liquid mixture obtained by calcining the mixed molding material of the vanadium-extracting converter dust and chloride salt of the present invention, the metallic iron in the pig iron is more than 95 wt%, and the slag layer is mainly composed of oxides such as Si, Mg, Ca, V, Cr, etc., with a total content of less than 5 wt%. Volatile metal elements such as lead and zinc first evaporate to the condensation area in the low temperature range of 400℃~600℃. Since the content of lead and zinc is relatively low, it is only necessary to clean the condensation area regularly.

[0012] The present invention calcines a mixed material of vanadium-extracting converter dust and chloride salts to obtain a slag-liquid mixture and gallium chloride volatiles. The gallium chloride volatiles are then collected in an alkaline solution, and then electrolyzed to obtain metallic gallium. Specifically, the gallium chloride volatiles are collected in an alkaline solution having a pH of 10.0 to 14.0 until the gallium concentration in the alkaline solution reaches 20 g / L, at which point the alkaline solution is replaced with a new one for gallium collection. More specifically, the gallium chloride volatiles are dissolved in an alkaline solution to obtain a gallium-rich alkaline solution. An appropriate amount of calcium oxide or sodium sulfide is added to the gallium-rich alkaline solution to remove impurities. After the impurities are removed, the gallium-rich alkaline solution is electrolyzed to obtain metallic gallium.

[0013] The present invention also includes extracting vanadium from the slag layer in the slag-liquid mixture and using the molten pig iron in the slag-liquid mixture for steelmaking. The slag layer in the slag-liquid mixture can be fed into a vanadium extraction system for vanadium extraction, while the molten pig iron in the slag-liquid mixture can be directly fed into the steelmaking process, thus achieving good economic value.

[0014] The present invention provides a gallium extraction process from vanadium-extracting converter dust. The gallium extraction process provided by the present invention realizes carbon-free emission from secondary resource ironmaking, while directly recovering gallium with alkaline solution, avoiding the introduction of highly polluting organic matter, and simultaneously realizing effective separation of gallium, iron, and vanadium. The gallium extraction process is short, without acidic leaching and extraction processes, which is at least half the length of other processes, avoiding the introduction of organic components into the gallium recovery system by extraction or ion exchange resin, and having a good impurity removal effect. The gallium extraction process provided by the present invention can ultimately extract gallium from gallium-containing secondary resources with a high recovery rate of up to 95%, and the extracted gallium meets the national standard for industrial gallium. At the same time, the by-products produced can be recycled into the vanadium extraction and ironmaking systems to obtain by-products with higher economic value. Excess chloride salts in the system can also be collected regularly. Since the chloride salts are relatively pure, they can be directly recycled into the first step of the gallium extraction process to mix with the vanadium-extracting converter dust, which has good economic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a flow chart of the gallium extraction process for gallium-containing secondary resources provided by the present invention. DETAILED DESCRIPTION

[0016] The present invention discloses a gallium extraction process for vanadium-extracting converter dust. Those skilled in the art may refer to the contents of this document and appropriately improve the process parameters to achieve this. It is particularly important to note that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in the present invention. The methods and applications of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the methods and applications herein without departing from the content, spirit, and scope of the present invention to implement and apply the technology of the present invention.

[0017] like Figure 1 As shown, Figure 1 This is a flow chart of the gallium extraction process for gallium-containing secondary resources provided by the present invention.

[0018] The present invention will be further described below with reference to the embodiments:

[0019] Example 1

[0020] The gallium-enriched secondary resource is primarily composed of 85 wt% Fe2O3, 3 wt% SiO2, and 5 wt% ZnO. The remainder is 1 wt% Na2O, 0.7 wt% MgO, 1.4 wt% CaCO3, 0.3 wt% Al2O3, 0.1 wt% TiO2, 0.6 wt% V2O5, 0.4 wt% Cr2O3, 0.9 wt% PbO, 0.2 wt% CuO, 0.1 wt% NiO, 0.6 wt% chloride, and 0.7 wt% sulfide. The gallium content of the secondary resource is 200 g / t.

[0021] The first step is to dry the gallium-containing secondary resource. The dried material is then mixed with sodium chloride, with the chloride added at twice the amount of secondary resource solids. After mixing, the mixture is pelletized to a diameter of 12 cm.

[0022] In the second step, the pellets are directly put into the vacuum furnace, the vacuum degree is controlled at 1 Pa, and the temperature is controlled at 1000 o C, calcined in a constant temperature zone for 10 hours. After calcination, a pig iron melt and a slag layer are formed. The metallic iron in the pig iron melt is 96 wt%, and the slag layer is mainly composed of oxides such as Si, Mg, Ca, V, and Cr, with a total content of less than 4 wt%. Volatile metal elements such as lead and zinc are calcined at 400 As the temperature rises to 800°C, the chloride salt decomposes and slowly releases chlorine gas, which reacts with the gallium in the pig iron to form gallium chloride, which evaporates in the vacuum.

[0023] The third step is to collect the volatilized gallium chloride with alkaline solution. The pH of the alkaline solution needs to be controlled in the range of 10.0~14.0 until the concentration of gallium in the alkaline solution reaches 20 g / L. New alkaline solution needs to be replaced to collect gallium.

[0024] In the fourth step, an appropriate amount of calcium oxide, sodium sulfide and other substances are added to the gallium-rich alkaline solution to remove impurities from the gallium-rich electrolyte. After impurities are removed, the gallium-rich solution is electrolyzed. The gallium recovery rate during the electrolysis process is 95%, and industrial gallium that meets GB / T 1475-2022 is finally obtained.

[0025] Example 2

[0026] The gallium-enriched secondary resource is primarily composed of 92 wt% Fe2O3, 1 wt% SiO2, and 1 wt% ZnO. The remainder is 1 wt% Na2O, 0.6 wt% MgO, 0.5 wt% CaCO3, 0.2 wt% Al2O3, 0.2 wt% TiO2, 0.6 wt% V2O5, 0.6 wt% Cr2O3, 0.7 wt% PbO, 0.2 wt% CuO, 0.1 wt% NiO, 0.3 wt% chloride, and 1 wt% sulfide. The gallium content of the secondary resource is 500 g / t.

[0027] The first step of the present invention is to dry the gallium-containing secondary resource. The dried material is then mixed with sodium chloride and potassium chloride, with the chloride added at a ratio of 0.5 times the solid content of the secondary resource. After mixing, the mixture is pressed into tablets with a diameter of 2 cm.

[0028] In the second step, the pellets are directly fed into a vacuum furnace, where the vacuum is controlled at 100 Pa and the temperature is controlled at 1300°C for 2 hours. This calcination results in a molten pig iron and a slag layer. The molten pig iron contains over 98 wt% metallic iron, while the slag layer is primarily composed of oxides of Si, Mg, Ca, V, and Cr, with a total content of less than 2 wt%. Volatile metal elements such as lead and zinc initially evaporate into the condensation zone at a low temperature of 600°C. As the temperature rises to 950°C, the chloride salts slowly decompose, releasing chlorine gas, which reacts with the gallium in the pig iron to form gallium chloride, which evaporates in the vacuum.

[0029] The third step is to collect the volatilized gallium chloride with alkaline solution. The pH of the alkaline solution needs to be controlled in the range of 10.0-14.0 until the concentration of gallium in the alkaline solution reaches 20 g / L. New alkaline solution needs to be replaced to collect gallium.

[0030] In the fourth step, an appropriate amount of calcium oxide, sodium sulfide and other substances are added to the gallium-rich alkaline solution to remove impurities from the gallium-rich electrolyte. After impurities are removed, the gallium-rich solution is electrolyzed. The gallium recovery rate during the electrolysis process is 94%, and industrial gallium that meets GB / T 1475-2022 is finally obtained.

[0031] Comparative Example 1

[0032] The gallium-enriched secondary resource is primarily composed of 85 wt% Fe2O3, 3 wt% SiO2, and 5 wt% ZnO. The remainder is 1 wt% Na2O, 0.7 wt% MgO, 1.4 wt% CaCO3, 0.3 wt% Al2O3, 0.1 wt% TiO2, 0.6 wt% V2O5, 0.4 wt% Cr2O3, 0.9 wt% PbO, 0.2 wt% CuO, 0.1 wt% NiO, 0.6 wt% chloride, and 0.7 wt% sulfide. The gallium content of the secondary resource is approximately 200 g / t.

[0033] The first step is to dry the gallium-containing secondary resource. The dried material is then mixed with sodium chloride, with the chloride added at a concentration three times the amount of secondary resource solids. After mixing, the mixture is pelletized to a diameter of 12 cm.

[0034] In the second step, the pellets are directly fed into a vacuum furnace, where the vacuum is controlled at 1 Pa and the temperature is controlled at 1000°C, where they are calcined in a constant temperature zone for 10 hours. After calcination, a molten pig iron and a slag layer are formed. The molten pig iron contains 96 wt% metallic iron, while the slag layer is primarily composed of oxides of Si, Mg, Ca, V, and Cr, with a total content of less than 4 wt%. Volatile metal elements such as lead and zinc initially evaporate into the condensation zone at 400°C. As the temperature rises to 800°C, the chloride salts slowly decompose, releasing chlorine gas, which reacts with the gallium in the pig iron to form gallium chloride. The gallium chloride evaporates under vacuum, but due to the excessive addition of sodium chloride, some of the sodium chloride evaporates along with the gallium chloride. During the gallium chloride collection process, due to the high salt content in the alkali solution, salt precipitation occurs before the gallium concentration in the alkali solution reaches 20 g / L. This salt precipitation removes some gallium, thus reducing the gallium recovery rate. After impurity removal, the gallium recovery rate is only around 80%.

[0035] Comparative Example 2

[0036] The gallium-enriched secondary resource is primarily composed of 92 wt% Fe2O3, 1 wt% SiO2, and 1 wt% ZnO. The remainder is 1 wt% Na2O, 0.6 wt% MgO, 0.5 wt% CaCO3, 0.2 wt% Al2O3, 0.2 wt% TiO2, 0.6 wt% V2O5, 0.6 wt% Cr2O3, 0.7 wt% PbO, 0.2 wt% CuO, 0.1 wt% NiO, 0.3 wt% chloride, and 1 wt% sulfide. The gallium content of the secondary resource is 500 g / t.

[0037] The first step of the present invention is to dry the gallium-containing secondary resource. The dried material is then mixed with sodium chloride and potassium chloride, with the chloride added at a ratio of 0.5 times the solid content of the secondary resource. After mixing, the mixture is pressed into tablets with a diameter of 2 cm.

[0038] In the second step, the pellets are directly placed in a vacuum furnace, where the vacuum is controlled at 200 Pa and the temperature is controlled at 1300°C for 2 hours. This results in a molten pig iron and a slag layer. The molten pig iron contains approximately 80 wt% metallic iron, while the slag layer is primarily composed of oxides such as Fe, Si, Mg, Ca, V, and Cr, totaling approximately 20 wt%. Furthermore, the chloride salts are not fully decomposed, resulting in only a small amount of chlorine gas, which does not meet the conditions for the formation of gallium chloride.

[0039] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A gallium extraction process for vanadium extraction converter dust, characterized in that: The following steps are involved: calcining a mixed molded material of vanadium-extracting converter dust and chloride salt to obtain a slag-liquid mixture and gallium chloride volatiles, dissolving the gallium chloride volatiles in alkali and then electrolyzing them to obtain metallic gallium; The calcination temperature is 1000° C. to 1300° C., and the calcination vacuum degree is 1 Pa to 100 Pa.

2. The gallium extraction process according to claim 1, characterized in that: The mass dosage of the chloride salt is 0.5 to 2 times the mass dosage of the vanadium extraction converter dust.

3. The gallium extraction process according to claim 1, characterized in that: The chloride salt is selected from one or more of sodium chloride, potassium chloride and ammonium chloride.

4. The gallium extraction process according to claim 1, characterized in that: The diameter of the mixed molding material of the vanadium extraction converter dust and chloride salt is 2 cm to 12 cm.

5. The gallium extraction process according to claim 1, characterized in that: Based on 1 t of the mixed molding material of the vanadium-extracting converter dust and chloride salt, the calcination time is 2 h to 10 h.

6. The gallium extraction process according to claim 1, characterized in that: The gallium content of the vanadium-extracting converter dust is 200 g / t to 500 g / t.

7. The gallium extraction process according to claim 6, characterized in that: Excluding the gallium content, the vanadium-extracting converter dust also includes 85 wt% to 92 wt% Fe2O3, 1 wt% to 3 wt% SiO2, 1 wt% to 5 wt% ZnO and less than 10 wt% of other impurities.

8. The gallium extraction process according to claim 7, characterized in that: The other impurities include Na2O, MgO, CaCO3, Al2O3, TiO2, V2O5, Cr2O3, PbO, CuO, NiO, chlorides and sulfides.

9. The gallium extraction process according to claim 1, characterized in that: The alkaline dissolution is carried out at a pH of 10.0-14.

0.

10. The gallium extraction process according to claim 1, characterized in that: The method also includes extracting vanadium from the slag layer in the slag-liquid mixture and making steel from the molten pig iron in the slag-liquid mixture.

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