Method for recovering antimony from low-grade complex oxidized antimony resources and simultaneously fixing fluorine

Abstract

The application discloses a low-grade complex oxidized antimony resource recovery antimony and fluorine fixation method, and belongs to the technical field of efficient recovery and reuse of metal mineral resources.The application comprises the following steps: (1) crushing low-grade complex oxidized antimony resources, uniformly mixing the crushed low-grade complex oxidized antimony resources with carbonaceous reducing agent A, and preparing a mixture I into a ball; (2) drying the ball obtained in the step (1), mixing the dried ball with carbonaceous reducing agent B, and roasting the mixture II, collecting flue gas generated in the roasting, and cooling the flue gas to obtain high-quality antimony-containing smoke dust.The application realizes efficient and high-quality recovery of antimony in low-grade complex oxidized antimony resources by a green and low-cost method, and solves the industrial problem of efficient utilization of low-grade complex oxidized antimony resources.

Description

Technical Field

[0001] This invention belongs to the field of efficient recycling and reuse technology of metal mineral resources, and relates to a method for recovering antimony and fluorine fixation in low-grade complex oxidized antimony resources. Background Technology

[0002] Antimony is an important strategic resource for my country and an indispensable key rare metal. my country has relatively abundant antimony 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 mining and utilization has been highly developed, resulting in large-scale resource consumption. Most of the large and super-large operating mines have been in operation for over 50 years, and 63% of the economically valuable antimony resources have already been consumed.

[0003] my country is the world's largest producer of antimony, boasting the world's largest reserves. Its smelting technology is among the most advanced in the antimony industry. Technological innovations, such as low-carbon co-smelting and oxygen-enriched strengthening processes, have significantly improved resource utilization and environmental protection. Simultaneously, China leverages its complete industrial chain and technological barriers to consolidate its international competitive advantage. The efficient utilization technology of low-grade, complex oxide-type antimony resources has become a key area for breakthroughs.

[0004] Currently, domestic and international research has been conducted on the utilization of antimony oxide resources, mainly focusing on processes such as hand sorting, gravity separation, flotation, sulfide flotation, combined gravity-flotation, and roasting. The valuable minerals in antimony oxide resources have fine particle sizes and complex symbiotic relationships with other minerals, making efficient beneficiation one of the world's major challenges. Low-grade complex antimony oxide resources have low antimony content, complex phases, and high levels of impurities such as fluorine and iron. Currently, metallic antimony is typically obtained through antimony oxide reduction smelting. However, due to the low antimony content and complex phases in low-grade complex antimony oxide resources, the high-temperature reduction smelting process easily generates antimony alloys, resulting in low antimony recovery rates. Maintaining high antimony recovery rates during reduction smelting requires the addition of complex additives, increasing smelting costs and reducing economic efficiency. Furthermore, low-grade complex antimony oxide resources often contain fluorine impurities, which easily volatilize during the molten pool smelting process, causing secondary pollution.

[0005] Therefore, it is necessary to provide a method for synergistic fluorine fixation and antimony recovery from low-grade complex antimony oxide resources through roasting, so as to improve the antimony recovery rate from low-grade complex antimony oxide 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] To overcome the problems in the prior art, this invention utilizes a roasting method to recover antimony from low-grade, complex oxidized antimony resources, while simultaneously fixing fluorine. This effectively improves the antimony recovery rate and fixes fluorine impurities in the roasting residue, preventing them from entering the flue gas. This reduces the impurity content in the final recovered product, increases the purity and quality of the recovered antimony resources, and reduces secondary pollution.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0008] The method includes the following steps:

[0009] (1) After crushing the low-grade complex antimony oxide resources, mix them evenly with carbonaceous reducing agent A, and then form mixture I into pellets. Mixture I can be formed into pellets using conventional granulation technology.

[0010] (2) The pellets obtained in step (1) are dried, and then the dried pellets are mixed evenly with carbonaceous reducing agent B. The mixture II is roasted, the flue gas generated during roasting is collected, and the flue gas is cooled to obtain smoke dust containing high-quality antimony, thereby achieving efficient and high-quality antimony recovery.

[0011] Preferably, in step (1), the low-grade complex oxidized antimony resources include at least one of basaltite, antimony travertine, red antimony travertine, yellow antimony travertine, antimony ochre, sulfoxylated antimony calcium stone, antimony calcium stone, and chemically dissolved antimony, wherein the low-grade complex oxidized antimony resources contain an antimony mass fraction of 1.0~10%.

[0012] Preferably, in step (1), the particle size of the low-grade complex oxide antimony resource after crushing is 50~300µm.

[0013] Preferably, the low-grade complex oxide antimony resource also includes antimony smelting waste residue, wherein the mass fraction of the antimony smelting waste residue in the low-grade complex oxide antimony resource does not exceed 15%.

[0014] Preferably, the carbonaceous reducing agent A exhibits higher carbon dioxide reactivity than anthracite within a temperature range of 600-900℃. 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 including lignite, bituminous coal, and semi-coke. When the carbonaceous reducing agent A is a mixture, the mass ratio of the substances can be arbitrary.

[0015] Preferably, in step (1), the mixing mass ratio of low-grade complex oxide antimony resources to carbonaceous reducing agent A is antimony resources: carbonaceous reducing agent A = 100: (1~8).

[0016] Preferably, in step (2), the calcination heating rate is 5~30℃ / min.

[0017] Preferably, in step (2), the calcination temperature is 600~950℃ and the holding time is 20~120min.

[0018] Preferably, in step (2), the ash content of the carbonaceous reducing agent B is <18%, and the particle size of the carbonaceous reducing agent B is 74μm~3cm. For example, substances such as bituminous coal, petroleum coke, and coke all meet the requirements in terms of ash content. 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, or a mixture of bituminous coal, petroleum coke, and coke. When the carbonaceous reducing agent B is a mixture, the mixing mass ratio of the substances can be arbitrary.

[0019] Preferably, in step (2), the mass ratio of the pellets to the carbonaceous reducing agent B is pellets: carbonaceous reducing agent B = 100: (5~30).

[0020] In the process of recovering antimony resources in this invention, complex antimony phases include stibnite, antimony travertine (Sb₂O₃), ruthenium stibnite (Sb₂S₂O), and sulfite (CaSb). 10 O 10 S6), stibnite (Sb2O4), stibnite (Sb2O4·H2O), and calcium antimonyite ((Ca,Fe,Mn,Na)2(Sb,Ti)2O6(O,OH,F)), etc., involve the following chemical equations:

[0021] Sb2O3(g)+CO(g)=Sb(g)+CO2(g);

[0022] Sb₂O₃(s) = Sb₂O₃(g);

[0023] (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;

[0024] (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;

[0025] Sb2O3(g)+CaF2(s)=Sb3O2F5(g)+5CaO;

[0026] C(s) + CO2(g) = 2CO(g).

[0027] The beneficial effects of this invention are:

[0028] 1. This invention couples key parameters such as temperature, the physicochemical properties of carbonaceous reducing agents, and the method of addition to selectively convert complex antimony phases into Sb(g), inhibiting the formation of Sb2O3(g) and Sb alloys, thereby hindering the formation of Sb3O2F5(g). This achieves efficient and high-quality recovery of antimony from low-grade complex oxide antimony resources, with an antimony recovery rate of over 95%, an antimony enrichment rate of over 10% in flue dust, and a fluorine curing rate of over 95%.

[0029] 2. A small amount of low-temperature reactive carbonaceous reducing agent A is granulated with low-grade complex oxidized antimony resources to ensure a reducing atmosphere inside the pellets within the low-temperature range to promote Sb(g) formation. Low temperature and Sb(g) formation inhibit fluorine volatilization. The introduction of coarse-particle, low-ash carbonaceous reducing agent B avoids secondary oxidation inside the pellets during the combustion process, while the low ash content ensures efficient enrichment of antimony in the flue dust.

[0030] 3. In the process of antimony recovery, only carbonaceous reducing agent A and carbonaceous reducing agent B are required, without the need to add other chemical reagents. Furthermore, the recovery process involves almost no liquid substances, which can effectively reduce the generation of pollutants such as waste liquid. At the same time, the fluorine is fixed, reducing the probability of secondary pollution caused by fluorine volatilization and improving the environmental friendliness of the recovery process.

[0031] 4. The present invention has a simple recycling process, requires fewer additives, and has a low cost. It can achieve efficient and high-quality recovery of antimony from low-grade complex oxide antimony resources that are difficult to process in a green, environmentally friendly and low-cost manner, thus solving the industry problem of efficient utilization of low-grade complex oxide antimony resources. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the process flow of the method of the present invention. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0034] Example 1

[0035] This embodiment recovers antimony from low-grade, complex oxidizing antimony resources using the following method:

[0036] (1) Low-grade complex antimony ore (single antimony ore) is mixed with antimony smelting waste and crushed to 200µm (antimony smelting waste is added at a ratio of 15%) to obtain low-grade complex antimony ore (containing 5.35% antimony, 2.14% fluorine, and 10.71% iron). The low-grade complex antimony ore is then mixed with semi-coke to form pellets (mixture I). The ratio of low-grade complex antimony ore to semi-coke is antimony ore: semi-coke = 100:8. Mixture I can be made into pellets using an existing pelletizing machine.

[0037] (2) The pellets are dried and mixed with bituminous coal (ash content: 10%) (the mixing ratio of pellets and bituminous coal is 100:5) to form mixture II. Mixture II is heated to 800°C by natural gas heating at a heating rate of 5°C / min and held for 40 min. The flue gas is then cooled to obtain high-quality antimony dust.

[0038] The composition of the roasting slag and flue dust was tested, and the results showed that the antimony content in the roasting slag was only 0.10%, and the fluorine curing rate was >97%. The antimony enrichment rate in the flue dust was >12, which proves that the method of the present invention can achieve high-quality and efficient recovery of antimony resources and reuse of smelting waste.

[0039] Example 2

[0040] This embodiment recovers antimony from low-grade, complex oxidizing antimony resources using the following method:

[0041] (1) Mix and crush low-grade complex oxidized antimony ore (stigmine, antimony travertine, red antimony ore, yellow antimony travertine, antimony ochre, sulfur-oxygenated antimony calcium stone, antimony calcium stone, and a mixture of chemically dissolved antimony) with antimony smelting waste to 50µm (the proportion of antimony smelting waste added is 7%) to obtain low-grade complex oxidized antimony resources (the low-grade complex oxidized antimony resources contain 2.21% antimony, 1.72% fluorine, and 8.23% iron). Mix the low-grade complex oxidized antimony resources 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 is antimony resources: bituminous coal and lignite mixture = 100:5.

[0042] (2) The pellets are dried and mixed with a mixture of petroleum coke and coke (ash content: 2%) (the ratio of pellets to bituminous coal is 100:30) to form mixture II. Mixture II is heated to 950°C by natural gas heating at a heating rate of 30°C / min and held for 20 min. The flue gas is then cooled to obtain high-quality antimony dust.

[0043] The composition of the roasting slag and flue dust was tested, and the results showed that the antimony content in the roasting slag was only 0.12%, and the fluorine curing rate was >98%. The antimony enrichment rate in the flue dust was >13, which proves that the method of the present invention can achieve high-quality and efficient recovery of antimony resources and reuse of smelting waste.

[0044] Example 3

[0045] (1) The low-grade complex oxidized antimony ore (stigmine, antimony travertine, red antimony ore, yellow antimony travertine, antimony ochre, sulfur-oxygenated antimony calcium stone, antimony calcium stone, and a mixture of chemically dissolved antimony) is crushed to 300 μm to obtain low-grade complex oxidized antimony resources (the low-grade complex oxidized antimony resources contain 5.35% antimony, 2.14% fluorine, and 10.71% iron). The low-grade complex oxidized antimony resources are mixed evenly 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 is antimony resources: lignite, bituminous coal, and semi-coke mixture = 100:1.

[0046] (2) The pellets are dried and mixed with a mixture of bituminous coal, petroleum coke and coke (ash content: 10%) (the ratio of pellets to bituminous coal is 100:15) to form mixture II. Mixture II is heated to 600°C by natural gas heating at a heating rate of 20°C / min and held for 120 min. The flue gas is then cooled to obtain high-quality antimony dust.

[0047] The composition of the roasting slag and flue dust was tested, and the results showed that the antimony content in the roasting slag was only 0.11%, and the fluorine curing rate was >97%. The antimony enrichment rate in the flue dust was >12, which proves that the method of the present invention can achieve high-quality and efficient recovery of antimony resources and reuse of smelting waste.

[0048] Comparative Example 1

[0049] This comparative example uses the same method and raw materials as Example 1 to recover antimony from low-grade complex oxidizing antimony resources. The difference is that in this comparative example, the ratio of antimony resources to semi-coke is antimony resources: semi-coke = 100:15.

[0050] Analysis of the composition of the roasting residue showed that the antimony content in the roasting residue was as high as 1.83%.

[0051] A comparison of Example 1 and Comparative Example 1 shows that excessive carbonaceous reducing agent A leads to the formation of antimony-iron alloy, which severely inhibits the recovery of antimony.

[0052] Comparative Example 2

[0053] This comparative example uses the same method and raw materials as Example 1 to recover antimony from low-grade complex oxidizing antimony resources. The difference is that in this comparative example, the carbonaceous reducing agent A is petroleum coke, and the carbon dioxide reactivity of petroleum coke is lower than that of anthracite in the temperature range of 600~900℃.

[0054] The composition of the roasting slag and flue dust was tested. The results showed that the antimony content in the roasting slag was 0.95%, the antimony enrichment rate in the flue dust was >10, but the fluorine curing rate was only 53%, and the fluorine content in the flue dust was significantly increased, making the flue dust difficult to apply.

[0055] A comparison of Example 1 and Comparative Example 2 shows that when carbonaceous reducing agent A is selected with substances whose performance does not meet the requirements, it will lead to the difficulty in selectively converting complex antimony phases into Sb(g), generating Sb2O3(g) which combines with calcium fluoride to generate gases such as Sb3O2F5. ​​The fluorine content in the flue dust will increase significantly, resulting in poor quality and making it difficult to apply. At the same time, the complex antimony phases will be difficult to efficiently reduce into antimony gas, leading to an increase in antimony content in the slag.

[0056] Comparative Example 3

[0057] This comparative example uses the same method and raw materials as Example 1 to recover antimony from low-grade complex oxidizing antimony resources. The difference is that in this comparative example, the carbonaceous reducing agent B is lignite with an ash content of 38%.

[0058] The composition of the roasting slag and flue dust was analyzed. 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 flue dust was only 5%.

[0059] A comparison of Example 1 and Comparative Example 3 shows that excessive ash content in carbonaceous reducing agent B leads to an increase in impurities such as alumina and silica in the flue dust, significantly reducing flue dust quality.

[0060] Comparative Example 4

[0061] This comparative example uses the same method and raw materials as Example 2 to recover antimony from low-grade complex oxidizing antimony resources. The difference is that in this comparative example, the low-grade complex oxidizing antimony resources are mixed with carbonaceous reducing agent A and carbonaceous reducing agent B in one step. The mass ratio of antimony resources to carbonaceous reducing agent A and carbonaceous reducing agent B is antimony resources: carbonaceous reducing agent A: carbonaceous reducing agent B = 100:5:30.

[0062] The composition of the roasted slag was analyzed, and the results showed that the antimony content in the roasted slag was 0.97%.

[0063] A comparison of Example 2 and Comparative Example 4 shows that direct mixing of carbonaceous reducing agents A and B with low-grade complex antimony resources leads to the formation of antimony-iron alloys, which inhibits antimony volatilization.

[0064] In summary, this invention enables efficient and high-quality recovery of antimony from low-grade complex antimony oxide resources through a green and low-cost method, solving the industry problem of efficient utilization of low-grade complex antimony oxide resources.

[0065] 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 intended to limit it. 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 to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A method for the synergistic antimony fixation and recovery of antimony from low-grade complex oxidized antimony resources, characterized in that: The method includes the following steps: (1) After crushing the low-grade complex antimony oxide resources, mix them evenly with carbonaceous reducing agent A, and then form the mixture I into pellets; (2) The pellets obtained in step (1) are dried, and then the dried pellets are mixed evenly with carbonaceous reducing agent B. The mixture II is roasted, the flue gas generated during roasting is collected, and the flue gas is cooled to obtain smoke dust containing high-quality antimony. The low-grade complex oxidized antimony resources include at least one of the following: stibnite, antimony travertine, red stibnite, yellow stibnite, antimony ochre, antimony sulfide, antimony calcite, and chemically dissolved antimony, wherein the antimony content in the low-grade complex oxidized antimony resources is 1.0-10% by mass. The carbonaceous reducing agent A exhibits higher reactivity to carbon dioxide than anthracite in the temperature range of 600~900℃. The carbonaceous reducing agent B has an ash content of <18% by mass and a particle size of 74μm~3cm.

2. The method according to claim 1, characterized in that: In step (1), the particle size of the low-grade complex oxide antimony resource after crushing is 50~300µm.

3. The method according to claim 1, characterized in that: The low-grade complex oxide antimony resources also include antimony smelting waste residue, wherein the mass fraction of antimony smelting waste residue in the low-grade complex oxide antimony resources does not exceed 15%.

4. The method according to claim 1, characterized in that: In step (1), the mixing mass ratio of low-grade complex oxide antimony resources and carbonaceous reducing agent A is antimony resources: carbonaceous reducing agent A = 100: (1~8).

5. The method according to claim 1, characterized in that: In step (2), the calcination heating rate is 5~30℃ / min.

6. The method according to claim 1, characterized in that: In step (2), the calcination temperature is 600~950℃ and the holding time is 20~120min.

7. The method according to claim 1, characterized in that: In step (2), the mass ratio of the pellets to carbonaceous reducing agent B is pellets: carbonaceous reducing agent B = 100: (5~30).

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