Method for comprehensive utilization of manganese-containing hematite based on leaching and suspension roasting combined treatment

Abstract

This application relates to the fields of mineral processing and hydrometallurgical technology, specifically to a comprehensive utilization method for manganese-bearing hematite based on the synergistic treatment of leaching and suspension roasting. The method includes the following steps: crushing the raw manganese-bearing hematite ore and grinding it to a particle size of -0.074 mm accounting for 60%~90%, obtaining ore powder; mixing the ore powder with a leaching agent and performing a leaching reaction, followed by solid-liquid separation to obtain a manganese-rich leachate and leaching residue; subjecting the leaching residue to suspension magnetization roasting to obtain roasting products; and subjecting the roasting products to magnetic separation to obtain iron concentrate and tailings. This method can overcome the current shortcomings of poor treatment effects for complex and difficult-to-process manganese-bearing hematite, achieving efficient iron-manganese separation, simultaneously obtaining high-quality iron concentrate and manganese-rich leachate, and overcoming problems such as difficulty in separating manganese and iron minerals, low iron recovery index, and the inability to economically recover manganese.

Description

Technical Field

[0001] This application relates to the fields of mineral processing and hydrometallurgical technology, specifically to a comprehensive utilization method for manganese-bearing hematite based on the synergistic treatment of leaching and suspension roasting. Background Technology

[0002] The iron and manganese minerals in manganese-bearing hematite are complexly interspersed, forming a dense oolitic structure, making it a typical complex and difficult-to-process ore. Traditional single physical beneficiation methods (such as magnetic separation, flotation, and gravity separation) are insufficient to achieve effective separation of iron and manganese, resulting in low iron concentrate grades, unrecoverable manganese, and extremely low resource utilization.

[0003] Suspension magnetic roasting-magnetic separation technology is one of the effective methods for processing complex and difficult-to-process iron ores. It can convert weakly magnetic hematite into strongly magnetic magnetite, which can then be recovered through magnetic separation. However, for manganese-containing hematite, directly using the suspension magnetic roasting-magnetic separation process still presents certain problems: First, the presence of manganese minerals interferes with the reduction process of hematite, resulting in low roasting conversion efficiency; second, the manganese-iron minerals remain tightly coexisting after roasting, leading to poor magnetic separation and difficulty in improving the grade of iron concentrate; and third, manganese is not effectively recovered during the separation process, resulting in resource waste.

[0004] While existing technologies have reported methods for treating manganese ore using leaching and iron ore using roasting-magnetic separation, none have organically combined leaching as a pretreatment with suspension magnetization roasting to leverage their synergistic effect for the comprehensive utilization of manganese-bearing hematite. Therefore, a new separation method for manganese-bearing hematite is needed, utilizing the enhancing mechanism of leaching on subsequent suspension magnetization roasting to ultimately achieve a synergistic improvement in separation indicators. Summary of the Invention

[0005] The purpose of this application is to overcome the shortcomings of the existing technology and provide a comprehensive utilization method for manganese-bearing hematite based on the synergistic treatment of leaching and suspension roasting. This method aims to solve the current defects of poor separation effect for complex and difficult-to-process manganese-bearing hematite, achieve efficient separation of iron and manganese, and simultaneously obtain high-quality iron concentrate and manganese-rich leachate. It also overcomes the problems of difficult separation of manganese and iron minerals, low iron recovery index, and the inability to economically recover manganese.

[0006] The objective of this application is achieved through the following technical solution: This application provides a comprehensive utilization method for manganese-bearing hematite based on the synergistic treatment of leaching and suspension roasting, including the following steps: S1. After crushing the raw manganese-containing hematite ore, grind it to a particle size of -0.074 mm accounting for 60%~90% to obtain mineral powder; S2. The mineral powder is mixed with the leaching agent and then subjected to a leaching reaction, followed by solid-liquid separation to obtain a manganese-rich leaching solution and leaching residue; S3. The leaching residue is subjected to suspension magnetization roasting to obtain the roasting product; S4. The roasted product is subjected to magnetic separation to obtain iron concentrate and tailings.

[0007] Furthermore, the leaching agent includes at least one of sulfuric acid, hydrochloric acid, nitric acid, and oxalic acid, and the mass fraction of the leaching agent is 1% to 10%.

[0008] Furthermore, the solid-liquid ratio of the mineral powder to the leaching agent is 1:(2~5).

[0009] Furthermore, the leaching reaction temperature is 30~90℃, and the leaching reaction time is 0.5~4 h.

[0010] Furthermore, the suspension magnetization calcination is carried out in an atmosphere containing reducing gas, the suspension magnetization calcination temperature is 750~1000℃, and the suspension magnetization calcination time is 5~25 min.

[0011] Furthermore, the reducing gas includes one of CO and H2, and the volume concentration of the reducing gas is 15% to 30%.

[0012] Furthermore, the magnetic field strength of the magnetic separation is 0.1~0.2 T.

[0013] Furthermore, it also includes S5: after purifying and concentrating the manganese-rich leachate, manganese carbonate is prepared.

[0014] The principle of this application is: The leaching process removes manganese minerals and disrupts the ore structure, creating favorable conditions for subsequent suspension roasting and magnetization roasting. This significantly enhances the conversion efficiency of hematite to magnetite. The optimized roasting effect also improves the selectivity and iron enrichment of the magnetic separation process. The synergy between the two results in a "1+1>2" effect.

[0015] The beneficial effects of this application are: 1. This application is the first to discover and utilize the synergistic effect between "leaching" and "suspension magnetization roasting". The leaching process not only recovers manganese, but also creates favorable conditions for subsequent roasting by removing manganese minerals and destroying the ore structure, which significantly improves the conversion efficiency of hematite to magnetite. The optimized roasting effect further greatly enhances the selectivity and enrichment effect of the magnetic separation process. The two work together to produce a "1+1>2" effect.

[0016] 2. Based on the synergistic effect between leaching and suspension magnetization roasting, this application ensures that the final iron concentrate has a total iron grade of no less than 60%, a total iron recovery rate of no less than 80%, and a manganese leaching recovery rate of no less than 80%, which is significantly better than the existing process.

[0017] 3. This application simultaneously obtained high-quality iron concentrate and manganese-rich leaching solution that can be used to prepare manganese carbonate, realizing the efficient recovery of the main valuable elements in the ore and greatly improving the comprehensive utilization efficiency of resources.

[0018] 4. The method of this application can be applied to complex and difficult-to-process manganese-bearing hematite, providing an effective technical route for the development and utilization of such long-term stagnant resources. Attached Figure Description

[0019] Figure 1 This application utilizes a beneficiation process flow diagram based on the synergistic treatment of manganese-containing hematite through leaching and suspension roasting. Detailed Implementation

[0020] The technical solution of this application is described in further detail below with reference to the accompanying drawings, but the scope of protection of this invention is not limited to the following description.

[0021] Example 1

[0022] Using manganese-bearing hematite from a certain area in Hunan Province as the candidate ore, chemical composition analysis (Table 1) and mineral composition analysis (Table 2) were conducted on the ore. It was found that the main chemical components in the ore were TFe (36.80%), Mn (5.86%), SiO2 (11.08%), and Al2O3 (13.91%). The main mineral components were hematite (30.43%), goethite (8.44%), pyrolusite (16.49%), halloysite (20.60%), and kaolinite (16.20%). The specific raw ore composition and mineral composition and content are shown in Table 1 and Table 2, respectively.

[0023] Table 1. Results of raw ore composition analysis (%) Table 2. Composition and content of raw ore minerals (%) The above-mentioned manganese-bearing hematite is beneficiated according to the following steps: S1. Crushing and grinding: After crushing the manganese-containing hematite, the ore is ground using a ball mill to a density of -0.074 mm (75%) to obtain mineral powder; S2. Leaching: The mineral powder is mixed with a 3% (w / w) dilute sulfuric acid solution at a solid-liquid ratio of 1:3, and then leached at 60°C for 2 h with stirring. The leaching solution and leaching residue are obtained by filtration. The concentration of Mn in the manganese-rich leaching solution is 12.50 g / L. S3. Suspension magnetization roasting: The leaching residue is placed in a suspension roasting furnace and roasted at 900°C for 15 min. The roasting atmosphere is a mixed gas of 20% CO and 80% N2; the roasting product is obtained. S4. Magnetic separation: After grinding the roasted product to 90% -0.038 mm, weak magnetic separation is performed with a magnetic field strength of 0.15 T to obtain iron concentrate and tailings.

[0024] After chemical titration analysis of the manganese-rich leachate and the iron concentrate, it was found that the TFe grade in the iron concentrate was 62.41%, the iron recovery rate was 82.47%, and the Mn content was 0.52%; the Mn concentration in the manganese-rich leachate was 12.50 g / L, and the manganese leaching recovery rate was 84.25%.

[0025] Example 2

[0026] Using the same manganese-bearing hematite as in Example 1, the manganese-bearing hematite was beneficiated according to the following steps: S1. Crushing and grinding: After crushing the manganese-containing hematite, the ore is ground using a ball mill to a density of -0.074 mm (75%) to obtain mineral powder; S2. Leaching: The mineral powder is mixed with a 5% hydrochloric acid solution at a solid-liquid ratio of 1:4, and then leached at 80°C for 3 hours. The mixture is filtered to obtain a manganese-rich leaching solution and leaching residue. The concentration of Mn in the manganese-rich leaching solution is 9.42 g / L. S3. Suspension magnetization roasting: The leaching residue is placed in a suspension roasting furnace and roasted at 900°C for 15 min. The roasting atmosphere is a mixed gas of 20% CO and 80% N2; the roasting product is obtained. S4. Magnetic separation: After grinding the roasted product to 90% -0.038 mm, weak magnetic separation is performed with a magnetic field strength of 0.15 T to obtain iron concentrate and tailings.

[0027] After chemical titration analysis of the manganese-rich leachate and the iron concentrate, it was found that the TFe grade in the iron concentrate was 60.67%, the iron recovery rate was 80.35%, and the Mn content was 0.34%; the Mn concentration in the manganese-rich leachate was 9.42 g / L, and the manganese leaching recovery rate was 86.69%.

[0028] Example 3

[0029] Using the same manganese-bearing hematite as in Example 1, the manganese-bearing hematite was beneficiated according to the following steps: S1. Crushing and grinding: After crushing the manganese-containing hematite, the ore is ground using a ball mill to a density of -0.074 mm (75%) to obtain mineral powder; S2. Leaching: The mineral powder is mixed with a 3% (w / w) dilute sulfuric acid solution at a solid-liquid ratio of 1:3, and then leached at 60°C for 2 h with stirring. The leaching solution and leaching residue are obtained by filtration. The concentration of Mn in the manganese-rich leaching solution is 12.64 g / L. S3. Suspension magnetization roasting: The leaching residue is placed in a suspension roasting furnace and roasted at 800°C for 10 min in a mixed gas environment of 25% H2 and 75% N2 to obtain the roasting product; S4. Magnetic separation: After grinding the roasted product to 90% -0.038 mm, weak magnetic separation is performed with a magnetic field strength of 0.15 T to obtain iron concentrate and tailings.

[0030] After chemical titration analysis of the manganese-rich leachate and the iron concentrate, it was found that the TFe grade in the iron concentrate was 61.16%, the iron recovery rate was 81.27%, and the Mn content was 0.42%; the Mn concentration in the manganese-rich leachate was 12.64 g / L, and the manganese leaching recovery rate was 84.92%.

[0031] Comparative Example 1 Using the same manganese-bearing hematite as in Example 1, the manganese-bearing hematite was beneficiated according to the following steps: S1. Crushing and grinding: After crushing the manganese-containing hematite, the ore is ground using a ball mill to a density of -0.074 mm (75%) to obtain mineral powder; S2. Suspension magnetization roasting: The mineral powder is placed in a suspension roasting furnace and roasted at 900°C for 15 min in a mixed gas environment of 20% CO and 80% N2; the roasting product is obtained. S3. Magnetic separation: After grinding the roasted product to 90% -0.038 mm, weak magnetic separation is performed with a magnetic field strength of 0.15 T to obtain iron concentrate and tailings.

[0032] After testing the iron concentrate using a chemical titration method, it was found that the TFe grade in the iron concentrate was 56.26%, the iron recovery rate was 76.25%, and the Mn content was 6.84%.

[0033] As can be seen from the comparison between Example 1 and Comparative Example 1, this application can effectively improve the grade and recovery rate of iron concentrate by synergistically applying "leaching" and "suspension magnetization roasting" to manganese-containing hematite, which fully demonstrates that there is a significant synergistic effect between "leaching pretreatment" and "suspension magnetization roasting", rather than a simple process superposition.

[0034] Comparative Example 2 (without suspension magnetization calcination) Using the same manganese-bearing hematite as in Example 1, the manganese-bearing hematite was beneficiated according to the following steps: S1. Crushing and grinding: After crushing the manganese-containing hematite, the ore is ground using a ball mill to a density of -0.074 mm (75%) to obtain mineral powder; S2. Leaching: The mineral powder is mixed with a 3% (w / w) dilute sulfuric acid solution at a solid-liquid ratio of 1:3, and then leached at 60°C for 2 h with stirring. The leaching solution and leaching residue are obtained by filtration. The concentration of Mn in the manganese-rich leaching solution is 11.88 g / L. S3. Magnetic separation: After grinding the leaching residue to 90% -0.038 mm, weak magnetic separation is performed with a magnetic field strength of 0.15 T to obtain iron concentrate and tailings.

[0035] After testing the iron concentrate using a chemical titration method, it was found that the TFe grade in the iron concentrate was 45.21%, the iron recovery rate was 63.57%, and the Mn content was 0.81%.

[0036] The above description is merely a preferred embodiment of this application. It should be understood that this application is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or the technology or knowledge in related fields. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of this invention should be within the protection scope of the appended claims.

Claims

1. A comprehensive utilization method for manganese-bearing hematite based on the synergistic treatment of leaching and suspension roasting, characterized in that, Includes the following steps: S1. After crushing the raw manganese-containing hematite ore, grind it to a particle size of -0.074 mm accounting for 60%~90% to obtain mineral powder; S2. The mineral powder is mixed with the leaching agent and then subjected to a leaching reaction, followed by solid-liquid separation to obtain a manganese-rich leaching solution and leaching residue; S3. The leaching residue is subjected to suspension magnetization roasting to obtain the roasting product; S4. The roasted product is subjected to magnetic separation to obtain iron concentrate and tailings.

2. The comprehensive utilization method for manganese-bearing hematite based on the synergistic treatment of leaching and suspension roasting according to claim 1, characterized in that, The leaching agent includes at least one of sulfuric acid, hydrochloric acid, nitric acid, and oxalic acid, and the mass fraction of the leaching agent is 1% to 10%.

3. The comprehensive utilization method for manganese-bearing hematite based on the synergistic treatment of leaching and suspension roasting according to claim 1, characterized in that, The solid-liquid ratio of the mineral powder to the leaching agent is 1:(2~5).

4. The comprehensive utilization method for manganese-bearing hematite based on the synergistic treatment of leaching and suspension roasting according to claim 1, characterized in that, The leaching reaction is carried out at a temperature of 30~90℃ for 0.5~4 h.

5. The comprehensive utilization method for manganese-bearing hematite based on the synergistic treatment of leaching and suspension roasting according to claim 1, characterized in that, The suspension magnetization calcination is carried out in an atmosphere containing reducing gas, the temperature of the suspension magnetization calcination is 750~1000℃, and the time of the suspension magnetization calcination is 5~25 min.

6. The comprehensive utilization method for manganese-bearing hematite based on the synergistic treatment of leaching and suspension roasting according to claim 5, characterized in that, The reducing gas includes one of CO and H2, and the volume concentration of the reducing gas is 15% to 30%.

7. The comprehensive utilization method for manganese-bearing hematite based on the synergistic treatment of leaching and suspension roasting according to claim 1, characterized in that, The magnetic field strength of the magnetic separation is 0.1~0.2 T.

8. The comprehensive utilization method for manganese-bearing hematite based on the synergistic treatment of leaching and suspension roasting according to claim 1, characterized in that, It also includes S5: after purifying and concentrating the manganese-rich leachate, manganese carbonate is prepared.

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