Antimony recovery and fluorine fixation synergistic method for low-grade complex oxidized antimony resource

Abstract

The invention discloses an antimony recovery and fluorine fixation synergistic method for low-grade complex oxidized antimony resources, and belongs to the technical field of efficient recovery and reutilization of metal mineral resources. The method comprises the following steps: (1) crushing a low-grade complex oxidized antimony resource, uniformly mixing the crushed low-grade complex oxidized antimony resource with a carbonaceous reducing agent A, and preparing a mixture I into pellets; and (2) the pellets obtained in the step (1) are dried, then the dried pellets are mixed with a carbonaceous reducing agent B, a mixture II is roasted, flue gas generated by roasting is collected, the flue gas is cooled, and the high-quality antimony smoke dust is obtained. According to the method, efficient and high-quality recovery of antimony in the low-grade complex oxidized antimony resources is achieved through the environment-friendly and low-cost method, and the industrial problem of efficient utilization of the low-grade complex oxidized antimony resources is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of efficient recovery and reuse of metal mineral resources, and relates to a method for recovering antimony and co-fixing fluorine from low-grade complex oxidized antimony resources. Background Art

[0002] Antimony is a vital strategic resource in my country and an indispensable key rare metal. my country boasts relatively abundant antimony ore resources, accounting for approximately 48% of global antimony production in 2023 (global antimony production was 83,000 tons). In recent years, my country's antimony ore development and utilization has been high, resulting in significant resource consumption. Most large and super-large operating mines have been operating for over 50 years, and 63% of the economically valuable antimony resources have already been depleted.

[0003] my country is the world's largest antimony producer, boasting the world's largest reserves. Its smelting technology leads the industry, and technological innovations, such as low-carbon synergistic smelting and oxygen-enriched intensification processes, have significantly improved resource utilization and environmental performance. China also leverages its comprehensive industrial chain and technological barriers to strengthen its international competitiveness. Efficient utilization of low-grade, complex oxidized antimony resources has become a key breakthrough area.

[0004] At present, relevant research on the utilization of oxidized antimony resources has been carried out both domestically and internationally, mainly using processes such as hand selection, gravity separation, flotation, sulfide flotation, combined gravity separation and flotation, and roasting. The embedded particle size of useful minerals in oxidized antimony resources is relatively fine and the symbiotic relationship with other minerals is complex. Its efficient beneficiation is one of the world's difficult problems in mineral processing. Low-grade complex oxidized antimony resources have low antimony content and complex phases, and high content of impurity elements such as fluorine and iron. At present, metallic antimony is usually obtained through antimony oxide reduction smelting. However, due to the low antimony content and complex antimony phases in low-grade complex oxidized antimony resources, the high-temperature process of reduction smelting is very likely to generate antimony alloys, resulting in low antimony recovery rates. In order to maintain a high antimony recovery rate during the reduction smelting process, it is necessary to add more complex additives, which increases the cost of reduction smelting and poor process economics. At the same time, since low-grade complex oxidized antimony resources usually contain fluorine impurities, fluorine is easily volatilized during the molten pool smelting process, causing secondary pollution.

[0005] Therefore, it is necessary to provide a method for roasting low-grade complex oxidized antimony resources to recover antimony and coordinate fluorine fixation, so as to improve the recovery rate of antimony in low-grade complex oxidized antimony resources, reduce the impurity content in the recovered antimony, improve the purity of the recovered antimony, and obtain high-quality antimony resources. Summary of the Invention

[0006] In order to overcome the problems in the background technology, the present invention recovers antimony from low-grade complex oxidized antimony resources by roasting, while achieving fluorine fixation. On the one hand, it effectively improves the antimony recovery rate, and on the other hand, it fixes the fluorine impurities in the roasting slag and prevents them from entering the flue gas, thereby reducing the impurity content in the final recovered product, improving the purity of the recovered antimony resources, improving the quality of the recovered antimony resources, and reducing secondary pollution.

[0007] In order to achieve the above object, the present invention is implemented through the following technical solutions: The method comprises the following steps: (1) After crushing low-grade complex oxidized antimony resources, the mixture is uniformly mixed with a carbonaceous reducing agent A, and the mixture I is pelletized. The mixture I can be pelletized using conventional pelletizing technology.

[0008] (2) Drying the pellets obtained in step (1), then uniformly mixing the dried pellets with the carbonaceous reducing agent B, and roasting the mixture II, collecting the flue gas generated by the roasting, and cooling the flue gas to obtain smoke containing high-quality antimony, thereby achieving efficient and high-quality recovery of antimony.

[0009] Preferably, in step (1), the low-grade complex oxidized antimony resource includes at least one of stibnite, antimony chalcanthite, red antimony chalcanthite, yellow antimony chalcanthite, antimony ochre, thiamite, and chemically dissolved antimony, and the mass fraction of antimony in the low-grade complex oxidized antimony resource is 1.0-10%.

[0010] Preferably, in step (1), the particle size of the low-grade complex oxidized antimony resource after crushing is 50-300 µm.

[0011] Preferably, the low-grade complex oxidized antimony resources also include antimony smelting waste slag, and the mass fraction of the antimony smelting waste slag in the low-grade complex oxidized antimony resources does not exceed 15%. Preferably, the carbonaceous reducing agent A has a higher reactivity with carbon dioxide than anthracite within the temperature range of 600-900°C. For example, lignite, bituminous coal, and semi-coke all meet the aforementioned requirements. The carbonaceous reducing agent A can be a single substance or a mixture, such as a mixture of lignite and bituminous coal, a mixture of bituminous coal and semi-coke, or a mixture of multiple substances, such as lignite, bituminous coal, and semi-coke. When the carbonaceous reducing agent A is a mixture, the mass ratio of the substances can be arbitrary.

[0012] Preferably, in step (1), the mixing mass ratio of the low-grade complex oxidized antimony resource and the carbonaceous reducing agent A is antimony resource: carbonaceous reducing agent A=100:(1-8).

[0013] Preferably, in step (2), the calcination heating rate is 5-30°C / min.

[0014] Preferably, in step (2), the calcination temperature is 600-950° C., and the holding time is 20-120 min.

[0015] Preferably, in step (2), the ash mass fraction of the carbonaceous reducing agent B is less than 18%, and the particle size of the carbonaceous reducing agent B is 74 μm to 3 cm. For example, the ash mass fraction of materials such as bituminous coal, petroleum coke, and coke all meet the requirements. Similarly, the carbonaceous reducing agent B can be a single substance or a mixture, such as a mixture of bituminous coal and petroleum coke, a mixture of bituminous coal and coke, a mixture of bituminous coal, petroleum coke, and coke, etc. When the carbonaceous reducing agent B is a mixture, the mixing mass ratio of the materials can be arbitrary.

[0016] Preferably, in step (2), the mass ratio of pellets to carbonaceous reducing agent B is pellets:carbonaceous reducing agent B=100:(5-30).

[0017] In the process of recovering antimony resources, the complex antimony phases include stibnite, antimony chalcanthite (Sb2O3), red antimony chalcanthite (Sb2S2O), calcium antimony sulfide (CaSb 10 O 10 S6), yellow antimonite (Sb2O4), yellow antimony flower (Sb2O4·H2O), antimonite ((Ca,Fe,Mn,Na)2(Sb,Ti)2O6(O,OH,F)), etc., involving the following chemical equations: Sb2O3(g)+CO(g)=Sb(g)+CO2(g); Sb2O3(s)=Sb2O3(g); (Sb2O 3, Sb2O 4, Sb2O5) 红锑矿、硫氧锑钙石、黄锑矿、黄锑华、锑钙石等 +CO(g)=Sb2O3(g)+CO2; (Sb2O 3, Sb2O 4, Sb2O5) 红锑矿、硫氧锑钙石、黄锑矿、黄锑华、锑钙石等 +CO(g)=Sb(g)+CO2; Sb2O3(g)+CaF2(s)=Sb3O2F5(g)+5CaO; C(s)+CO2(g)=2CO(g).

[0018] Beneficial effects of the present invention: 1. The present invention couples key parameters such as temperature, the physical and chemical properties of the carbonaceous reducing agent, and the method of addition to regulate the selective conversion of complex antimony phases into Sb(g), inhibit the formation of Sb2O3(g) and Sb alloys, and thus hinder the formation of Sb3O2F5(g). This achieves efficient and high-quality recovery of antimony from low-grade complex oxidized antimony resources, with an antimony recovery rate exceeding 95%, an antimony enrichment rate in smoke exceeding 10, and a fluorine solidification rate exceeding 95%.

[0019] 2. A small amount of low-temperature reactive carbonaceous reducing agent A is pelletized with low-grade complex oxidized antimony resources to ensure that the reducing atmosphere inside the pellets in the low-temperature range promotes the formation of Sb(g). The low temperature and Sb(g) formation inhibit the volatilization of fluorine. The introduction of coarse-grained low-ash carbonaceous reducing agent B avoids secondary oxidation inside the pellets during the burning process. At the same time, the low ash content ensures the efficient enrichment of antimony in the smoke.

[0020] 3. In the antimony recovery process of the present invention, only carbonaceous reducing agent A and carbonaceous reducing agent B are required, and no other chemical reagents are added. In addition, almost no liquid substances are involved in the recovery process, which can effectively reduce the generation of pollutants such as waste liquid. At the same time, fluorine is fixed, reducing the probability of secondary pollution caused by fluorine volatilization, thereby improving the environmental friendliness of the recovery process.

[0021] 4. The present invention has a simple recovery process, requires fewer additives, and has low costs. It can achieve efficient and high-quality recovery of antimony from difficult-to-process low-grade complex oxidized antimony resources in an environmentally friendly and low-cost manner, solving the industry's difficult problem of efficient utilization of low-grade complex oxidized antimony resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the process flow of the method of the present invention. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited to the contents described above.

[0024] Example 1 This example recovers antimony from low-grade complex oxidizing antimony resources by the following method: (1) Low-grade complex oxidized antimony ore (single antimony ore) and antimony smelting waste slag are mixed and crushed to 200 µm (the antimony smelting waste slag is added in an amount of 15%) to obtain a low-grade complex oxidized antimony resource (the low-grade complex oxidized antimony resource contains 5.35% antimony, 2.14% fluorine, and 10.71% iron). The low-grade complex oxidized antimony resource is uniformly mixed with semi-coke to form pellets (Mixture I). The addition ratio of the low-grade complex oxidized antimony resource to the semi-coke is antimony resource: semi-coke = 100:8. Mixture I can be made into pellets using an existing pelletizing machine.

[0025] (2) The pellets were dried and mixed with bituminous coal (ash content: 10%) (the mixing ratio of pellets to bituminous coal was 100:5) to obtain mixture II. The mixture II was heated to 800°C at a heating rate of 5°C / min by natural gas heating and kept at this temperature for 40 minutes. The flue gas was cooled to obtain high-quality antimony dust.

[0026] The components of the roasting slag and smoke were tested, and the results showed that the antimony content in the roasting slag was only 0.10%, the fluorine solidification rate was >97%, and the antimony enrichment rate in the smoke was >12, proving that the method of the present invention can achieve high-quality and efficient recovery of antimony resources and reuse of smelting waste slag.

[0027] Example 2 This example recovers antimony from low-grade complex oxidizing antimony resources by the following method: (1) Low-grade oxidized complex antimony ore (a mixture of stibnite, antimony chalcanthite, red antimony chalcanthite, yellow antimony chalcanthite, antimony ochre, sulfoantimonite, antimony chalcanthite, and chemically dissolved antimony) was mixed with antimony smelting waste slag and crushed to 50 µm (the addition ratio of antimony smelting waste slag was 7%) to obtain low-grade complex oxidized antimony resources (the low-grade complex oxidized antimony resources contained 2.21% antimony, 1.72% fluorine, and 8.23% iron). The low-grade complex oxidized antimony resources were uniformly mixed with a mixture of bituminous coal and lignite to form pellets (mixture I). The mixing mass ratio of antimony resources to the mixture of bituminous coal and lignite was antimony resources: bituminous coal and lignite mixture = 100:5.

[0028] (2) The pellets were dried and mixed with a mixture of petroleum coke and coke (ash content: 2%) (the mixing ratio of pellets to bituminous coal was 100:30) to obtain mixture II. The mixture II was heated to 950°C at a heating rate of 30°C / min by natural gas heating and kept at this temperature for 20 minutes. The flue gas was cooled to obtain high-quality antimony dust.

[0029] The components of the roasting slag and smoke were tested, and the results showed that the antimony content in the roasting slag was only 0.12%, the fluorine solidification rate was >98%, and the antimony enrichment rate in the smoke was >13, proving that the method of the present invention can achieve high-quality and efficient recovery of antimony resources and reuse of smelting waste slag.

[0030] Example 3 (1) Low-grade complex oxidized antimony ore (a mixture of stibnite, antimony chalcanthite, red antimony chalcanthite, yellow antimony chalcanthite, antimony ochre, antimony oxysulfide calcium antimony stone, antimony calcium antimony stone, and chemically dissolved antimony) was crushed to 300 μm to obtain low-grade complex oxidized antimony resources (the low-grade complex oxidized antimony resources contained 5.35% antimony, 2.14% fluorine, and 10.71% iron). The low-grade complex oxidized antimony resources were uniformly mixed with a mixture of lignite, bituminous coal, and semi-coke to form pellets (mixture I). The mixing mass ratio of the low-grade complex oxidized antimony resources to the mixture of lignite, bituminous coal, and semi-coke was antimony resources: lignite, bituminous coal, and semi-coke mixture = 100:1.

[0031] (2) The pellets were dried and mixed with a mixture of bituminous coal, petroleum coke, and coke (ash content: 10%) (the mixing ratio of pellets to bituminous coal was 100:15) to obtain mixture II. The mixture II was heated to 600°C at a heating rate of 20°C / min by natural gas heating and kept at this temperature for 120 min. The flue gas was cooled to obtain high-quality antimony dust.

[0032] The components of the roasting slag and smoke were tested, and the results showed that the antimony content in the roasting slag was only 0.11%, the fluorine solidification rate was >97%, and the antimony enrichment rate in the smoke was >12, proving that the method of the present invention can achieve high-quality and efficient recovery of antimony resources and reuse of smelting waste slag.

[0033] Comparative Example 1 This comparative example uses the same method and raw materials as Example 1 to recover antimony from low-grade complex oxidizing antimony resources, except that in this comparative example, the ratio of antimony resource to blue coke is antimony resource: blue coke = 100:15.

[0034] The composition of the roasting slag was tested, and the results showed that the antimony content in the roasting slag was as high as 1.83%.

[0035] By comparing Example 1 with Comparative Example 1, it can be seen that excessive carbonaceous reducing agent A will lead to the formation of antimony-iron alloy, which seriously inhibits the recovery of antimony.

[0036] Comparative Example 2 This comparative example uses the same method and raw materials as Example 1 to recover antimony from low-grade complex oxidizing antimony resources, except that in this comparative example, the carbonaceous reducing agent A uses petroleum coke, which has a lower reactivity with carbon dioxide than anthracite in the temperature range of 600-900°C.

[0037] The components of the roasting slag and smoke were tested, and the results showed that the antimony content in the roasting slag was 0.95%, and the antimony enrichment rate in the smoke was >10, but the fluorine solidification rate was only 53%. The fluorine content in the smoke was significantly increased, making the smoke difficult to use.

[0038] By comparing Example 1 with Comparative Example 2, it can be seen that when the carbonaceous reducing agent A selects a substance whose performance does not meet the requirements, it will lead to the difficulty of selectively converting the complex antimony phase into Sb(g), and Sb2O3(g) will be generated and combined with calcium fluoride to form gases such as Sb3O2F5. ​​The fluorine content in the smoke will increase significantly, the quality will be poor, and it will be difficult to use. At the same time, the complex antimony phase is difficult to be efficiently reduced to antimony gas, resulting in an increase in the antimony content in the slag.

[0039] Comparative Example 3 This comparative example uses the same method and raw materials as Example 1 to recover antimony from low-grade complex oxidizing antimony resources, except that in this comparative example, lignite is used as the carbonaceous reducing agent B, and the lignite ash content is 38%.

[0040] The components of the roasting slag and smoke were tested, and the results showed that the antimony content in the roasting slag was 0.13%, and the fluorine curing rate was >97%, but the antimony enrichment rate in the smoke was only 5.

[0041] By comparing Example 1 with Comparative Example 3, it can be seen that excessive ash content of the carbonaceous reducing agent B will lead to an increase in impurities such as aluminum oxide and silicon dioxide in the smoke, significantly reducing the quality of the smoke.

[0042] Comparative Example 4 This comparative example uses the same method and raw materials as Example 2 to recover antimony from low-grade complex oxidizing antimony resources, with the difference being that in this comparative example, the low-grade oxidizing complex antimony resources are mixed with carbonaceous reducing agent A and carbonaceous reducing agent B in one step, and the mass ratio of the mixture of antimony resources, carbonaceous reducing agent A and carbonaceous reducing agent B is antimony resource: carbonaceous reducing agent A: carbonaceous reducing agent B = 100:5:30.

[0043] The composition of the roasting slag was tested, and the results showed that the antimony content in the roasting slag was 0.97%.

[0044] By comparing Example 2 with Comparative Example 4, it can be seen that direct mixing of carbonaceous reducing agents A and B with low-grade complex antimony resources will lead to the formation of antimony-iron alloys, which inhibits antimony volatilization.

[0045] In summary, the present invention can achieve efficient and high-quality recovery of antimony from low-grade complex oxidized antimony resources through a green and low-cost method, solving the industry problem of efficient utilization of low-grade complex oxidized antimony resources.

[0046] Finally, it should be noted that the above preferred embodiments 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 through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A method for recovering antimony from low-grade complex oxidized antimony resources and coordinating fluorine fixation, characterized by: The method comprises the following steps: (1) After crushing the low-grade complex oxidized antimony resource, uniformly mix it with the carbonaceous reducing agent A, and make the mixture I into pellets; (2) Drying the pellets obtained in step (1), then uniformly mixing the dried pellets with the carbonaceous reducing agent B, and roasting the mixture II, collecting the flue gas generated by the roasting, and cooling the flue gas to obtain smoke containing high-quality antimony.

2. The method according to claim 1, wherein: In the step (1), the low-grade complex oxidized antimony resources include at least one of stibnite, antimony chalcanthite, red antimony chalcanthite, yellow antimony chalcanthite, antimony ochre, thiaborite, and chemically dissolved antimony, and the mass fraction of antimony in the low-grade complex oxidized antimony resources is 1.0-10%.

3. The method according to claim 1, wherein: In the step (1), the particle size of the low-grade complex oxidized antimony resource after crushing is 50-300 μm.

4. The method according to claim 2, wherein: The low-grade complex oxidized antimony resources also include antimony smelting waste slag. In the low-grade complex oxidized antimony resources, the mass fraction of antimony smelting waste slag does not exceed 15%.

5. The method according to claim 1, wherein: The carbonaceous reducing agent A has a higher reactivity with carbon dioxide than anthracite in the temperature range of 600-900°C.

6. The method according to claim 1, wherein: In the step (1), the mixing mass ratio of the low-grade complex oxidized antimony resource and the carbonaceous reducing agent A is antimony resource: carbonaceous reducing agent A=100:(1-8).

7. The method according to claim 1, wherein: In the step (2), the calcination heating rate is 5-30°C / min.

8. The method according to claim 1, wherein: In the step (2), the calcination temperature is 600-950° C., and the holding time is 20-120 min.

9. The method according to claim 1, wherein: In the step (2), the ash mass fraction of the carbonaceous reducing agent B is less than 18%, and the particle size of the carbonaceous reducing agent B is 74 μm to 3 cm.

10. The method according to claim 1, wherein: In the step (2), the mass ratio of the pellets to the carbonaceous reducing agent B is pellets: carbonaceous reducing agent B = 100: (5-30).

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