Method for efficiently separating iron and titanium from low-grade ilmenite

Abstract

The invention provides a method for efficiently separating iron and titanium from low-grade ilmenite, and belongs to the technical field of ferrotitanium resource recovery. According to the method, fine-ground ilmenite is subjected to flotation, acid leaching and alkaline leaching, impurity elements such as silicon, calcium and magnesium in the ilmenite are removed, and high-purity ilmenite is obtained; and then the ilmenite is subjected to melt separation treatment, molten iron and high titanium slag containing trace impurities are obtained, and the TiO2 grade of the titanium slag reaches 90% or above. Compared with titanium slag obtained through traditional smelting, the titanium slag obtained through the method is high in titanium element content, a large number of titanium-silicon-calcium-magnesium symbionts cannot be generated, the obtained titanium slag can be directly used for subsequent smelting of metal titanium, flotation is conducted firstly, then acid leaching and alkali leaching treatment is conducted, and the acid and alkali use amount is greatly reduced. The process method can effectively solve the problem of waste of titanium resources due to the fact that the smelting titanium slag cannot be treated in the traditional industry.

Description

Technical Field

[0001] The invention relates to the technical field of ilmenite resource recovery, and in particular to a method for efficiently separating iron and titanium from low-grade ilmenite. Background Art

[0002] Titanium and its derivatives are widely used in industries such as petrochemicals, electricity, deep-sea ships, metallurgy, aerospace, coatings, medical treatment and catalysis. They are important high-tech minerals required by strategic emerging industries and play a very important role in the future development of science and technology. The mineral sources of titanium are mainly ilmenite and rutile, but my country has relatively few reserves of rutile, which is easy to use, and mainly relies on ilmenite, which is difficult to use. In addition, the reserves of ilmenite resources are large, so the development and utilization of ilmenite is crucial to the protection of titanium resources.

[0003] Ilmenite is a symbiotic composite ore with multiple elements such as iron, titanium, calcium, magnesium, and silicon. Its comprehensive utilization is difficult. At present, the smelting process commonly used to smelt ilmenite causes most of the titanium in the ilmenite to enter the slag. The technology for recovering titanium from the slag is difficult and costly, resulting in a large amount of titanium resources being lost.

[0004] Due to the technical defects of traditional iron-making process, there are a large number of impurity elements such as calcium, magnesium, silicon, etc. in the titanium slag after smelting, which will produce a large number of titanium-silicon-calcium-magnesium symbionts. These symbionts cause titanium metal and other impurity metals to be tightly fused together, making the subsequent separation of metallic titanium much more difficult and the cost much higher, resulting in a huge waste of titanium resources.

[0005] In view of this, it is necessary to provide a method for efficiently utilizing titanium smelting slag. Summary of the invention

[0006] In view of the technical problems existing in the background technology, the present application provides a method for separating and recovering titanium from low-grade titanium slag and ilmenite, aiming to solve the problem that in the existing smelting process commonly used for smelting ilmenite, most of the titanium in ilmenite enters the slag, and the technology of recovering titanium from the slag is difficult and costly, resulting in a large amount of titanium resources being lost.

[0007] The present application provides a method for separating low-grade titanium slag from ferrotitanium and recovering titanium, which is characterized by comprising the following steps:

[0008] S1, finely grinding the ilmenite after magnetic separation to obtain sample 1;

[0009] S2, flotation the sample 1 to obtain ilmenite concentrate;

[0010] S3, finely grinding the ilmenite concentrate to obtain sample 2;

[0011] S4, acid leaching the sample 2, washing, filtering, and obtaining an acid leached concentrate;

[0012] S5, alkali leaching the acid leached concentrate, filtering, and drying to obtain high-purity ilmenite;

[0013] S6, melting and separating the high-purity ilmenite to obtain molten iron and high-titanium slag.

[0014] In the technical scheme of the embodiment of the present application, the ilmenite after fine grinding is first subjected to flotation, acid leaching, and alkali leaching to remove impurity elements such as silicon, calcium, and magnesium in the ilmenite to obtain high-purity ilmenite; the ilmenite is then subjected to smelting treatment to obtain molten iron and high-titanium slag containing trace impurities, and the TiO2 grade of the titanium slag reaches more than 90%. Compared with the titanium slag obtained by traditional smelting, the titanium slag obtained by the present invention has a high content of titanium element and does not produce a large amount of titanium-silicon-calcium-magnesium symbiosis. The obtained titanium slag can be directly used for the subsequent smelting of titanium metal, and first flotation and then acid leaching and alkali leaching are carried out, and the amount of acid and alkali used is greatly reduced. This process method can effectively solve the problem that the smelting titanium slag in the traditional industry cannot be treated, resulting in a waste of titanium resources.

[0015] In some embodiments, in step S1, fine grinding means that the grinding fineness is -0.074 mm, accounting for 60-75%.

[0016] In this embodiment, sample 1 is obtained by grinding ilmenite after magnetic separation for mineral processing.

[0017] In some embodiments, in step S2, the flotation steps include preliminary desulfurization, one roughing selection, and three fine selections; in desulfurization, the collector is ethyl xanthate and the frother is 2# oil; in roughing and fine selection, the adjusting agent is a sulfuric acid solution with a concentration of 5wt%; the collector is sodium oleate and benzohydroxamic acid in a mass ratio of 4 to 7:3.

[0018] In this embodiment, the sulfide ore is first removed by pre-flotation, and then the ilmenite concentrate containing a small amount of calcium, magnesium and silicon impurities is obtained through a one-rough and three-fine flotation process.

[0019] In some embodiments, in step S3, fine grinding means that the grinding fineness is -0.025mm≥80%.

[0020] In this example, sample 2 was obtained by grinding ilmenite concentrate for subsequent acid leaching.

[0021] In some embodiments, in step S4, during acid leaching, the mass ratio of sample 2 to the acid solution is 10 to 40:3; the leaching temperature is 23 to 27°C; the stirring rate is 310 r / min; the acid solution is a mixture of one or more acids selected from sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, and hydrofluoric acid; and the concentration of the acid solution is 8 to 20 wt%.

[0022] In this embodiment, impurity elements such as calcium and magnesium in sample 2 are dissolved by acid leaching.

[0023] In some embodiments, in step S5, in alkaline leaching, the mass ratio of acid leaching concentrate to alkaline solution is 10-40:3; the leaching temperature is 100-150°C; the stirring rate is 310r / min; the alkaline solution is a mixture of one or more alkalis selected from sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, and ammonia water; and the concentration of the alkaline solution is 8-20wt%.

[0024] In this embodiment, silicon impurity elements in the acid leached concentrate are dissolved by alkaline leaching.

[0025] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 This is a process flow chart of the method for separating low-grade titanium slag from ferrotitanium and recovering titanium in Example 1 of the present application. DETAILED DESCRIPTION

[0028] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0030] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0031] In order to solve the problem that most of the titanium in ilmenite enters the slag in the existing smelting process commonly used for smelting ilmenite, the technical difficulty and high cost of recovering titanium from the slag are great, resulting in the loss of a large amount of titanium resources, the present application provides a method for separating low-grade titanium slag from titanium and iron and recovering titanium. The present application obtains high-purity ilmenite by subjecting the finely ground ilmenite to flotation, acid leaching, and alkali leaching to remove impurity elements such as silicon, calcium, and magnesium in the ilmenite; and then smelting the ilmenite to obtain molten iron and high-titanium slag containing trace impurities, and the TiO2 grade of the titanium slag reaches more than 90%. Compared with the titanium slag obtained by traditional smelting, the titanium slag obtained by the present invention has a high content of titanium elements and will not produce a large amount of titanium-silicon-calcium-magnesium symbionts. The obtained titanium slag can be directly used for the subsequent smelting of titanium metal, and first flotation and then acid leaching and alkali leaching are carried out, and the amount of acid and alkali used is greatly reduced. The process method can effectively solve the problem that the smelting titanium slag in the traditional industry cannot be treated, resulting in the waste of titanium resources.

[0032] The present application provides a method for separating low-grade titanium slag from ferrotitanium and recovering titanium, comprising the following steps:

[0033] S1, finely grinding the ilmenite after magnetic separation to obtain sample 1;

[0034] S2, flotation the sample 1 to obtain ilmenite concentrate;

[0035] S3, finely grinding the ilmenite concentrate to obtain sample 2;

[0036] S4, acid leaching the sample 2, washing, filtering, and obtaining an acid leached concentrate;

[0037] S5, alkali leaching the acid leached concentrate, filtering, and drying to obtain high-purity ilmenite;

[0038] S6, melting and separating the high-purity ilmenite to obtain molten iron and high-titanium slag.

[0039] In the technical scheme of the embodiment of the present application, the ilmenite after fine grinding is first subjected to flotation, acid leaching, and alkali leaching to remove impurity elements such as silicon, calcium, and magnesium in the ilmenite to obtain high-purity ilmenite; the ilmenite is then subjected to smelting treatment to obtain molten iron and high-titanium slag containing trace impurities, and the TiO2 grade of the titanium slag reaches more than 90%. Compared with the titanium slag obtained by traditional smelting, the titanium slag obtained by the present invention has a high content of titanium element and does not produce a large amount of titanium-silicon-calcium-magnesium symbiosis. The obtained titanium slag can be directly used for the subsequent smelting of titanium metal, and first flotation and then acid leaching and alkali leaching are carried out, and the amount of acid and alkali used is greatly reduced. This process method can effectively solve the problem that the smelting titanium slag in the traditional industry cannot be treated, resulting in a waste of titanium resources.

[0040] Furthermore, in some embodiments, in step S1, fine grinding means that the grinding fineness is -0.074 mm, accounting for 60-75%.

[0041] In the technical solution of the embodiment of the present application, sample 1 is obtained by grinding the ilmenite after magnetic separation for mineral processing.

[0042] Furthermore, in some embodiments, in step S2, the flotation step includes pre-desulfurization, one roughing and three fine separations; in the desulfurization, the collector is ethyl xanthate and the frother is 2# oil; in the roughing and fine separations, the adjusting agent is a sulfuric acid solution with a concentration of 5wt%; the collector is sodium oleate and benzohydroxamic acid in a mass ratio of 4 to 7:3.

[0043] In the technical solution of the embodiment of the present application, in this embodiment, the sulfide ore is first removed by pre-flotation, and then the ilmenite concentrate containing a small amount of calcium, magnesium and silicon impurities is obtained through a one-rough and three-fine flotation process.

[0044] Furthermore, in some embodiments, in step S3, fine grinding refers to grinding fineness of -0.025 mm ≥ 80%.

[0045] In the technical solution of the embodiment of the present application, sample 2 is obtained by grinding the ilmenite concentrate for subsequent acid leaching.

[0046] Further, in some embodiments, in step S4, in the acid leaching, the mass ratio of sample 2 and the acid solution is 10-40:3; the leaching temperature is 23-27°C; the stirring rate is 310r / min; the leaching time is 50-100min; the acid solution is a mixture of one or more acids selected from sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, and hydrofluoric acid; and the concentration of the acid solution is 8-20wt%.

[0047] In the technical solution of the embodiment of the present application, impurity elements such as calcium and magnesium in sample 2 are dissolved by acid leaching.

[0048] Furthermore, in some embodiments, in step S5, in alkaline leaching, the mass ratio of the acid leaching concentrate to the alkaline solution is 10-40:3; the leaching temperature is 100-150°C; the stirring rate is 310r / min; the leaching time is 100-120min; the alkaline solution is a mixture of one or more alkalis selected from sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, and ammonia water; and the concentration of the alkaline solution is 8-20wt%.

[0049] In the technical solution of the embodiment of the present application, the silicon impurity elements in the acid leaching concentrate are dissolved by alkali leaching.

[0050] Furthermore, in some embodiments, in step S6, during the melting treatment, the melting temperature is 1400-2000°C.

[0051] In the technical solution of the embodiment of the present application, iron and titanium are separated by smelting treatment to obtain high-titanium slag.

[0052] Some specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used that do not specify the manufacturer are all conventional products that can be obtained commercially.

[0053] Example 1

[0054] This embodiment provides a method for separating low-grade titanium slag from ferrotitanium and recovering titanium. The process flow chart is as follows: Figure 1 As shown, the specific steps include:

[0055] The ilmenite after magnetic separation is finely ground to -0.074mm, accounting for 67%, and then water is added to the pulp concentration of 33%; the pulp is added to the XFD-1L flotation machine, and 400g / t of ethyl xanthate and 28g / t of 2# oil are added for flotation. After the flotation is completed, 1000g / t of sulfuric acid, 900g / t of sodium oleate and 500g / t of benzohydroxamic acid are added to the flotation tank for one roughing and three concentrating to obtain ilmenite concentrate; the obtained ilmenite concentrate is finely ground to -0. 025mm accounts for 85%; add flotation concentrate and 200g / t hydrochloric acid solution with a concentration of 10wt% into the reactor, react at 25°C and a stirring rate of 310r / min for 100 minutes, and filter to obtain acid leaching concentrate; add acid leaching concentrate and 200g / t sodium hydroxide solution with a concentration of 10wt% into the reactor, react at 100°C and a stirring rate of 310r / min for 120 minutes, and filter to obtain high-purity ilmenite; calcined at 1600°C in an electric furnace to obtain high-titanium slag.

[0056] Through mineralogical analysis, it was found that the TiO2 grade of the ilmenite in this embodiment was 48.34%; the TiO2 grade of the titanium slag was 90%.

[0057] Examples 2 to 3 and Comparative Examples 1 to 2

[0058] Examples 2 to 3 and Comparative Examples 1 to 2 respectively provide a method for separating low-grade titanium slag from titanium and iron and recovering titanium. Compared with Example 1, the difference is that the usage ratio of the collector sodium oleate and benzohydroxamic acid in flotation is different. The other steps are roughly the same as those in Example 1 and will not be repeated here.

[0059] The specific dosages of the collector sodium oleate and benzohydroxamic acid in Examples 2 to 3 and Comparative Examples 1 to 2 and the corresponding ilmenite TiO2 grade and titanium slag TiO2 grade are shown in Table 1.

[0060] Table 1 The dosage of sodium oleate and benzohydroxamic acid and the corresponding ilmenite TiO2 grade and titanium slag TiO2 grade in Examples 2 to 3 and Comparative Examples 1 to 2

[0061]

[0062]

[0063] It can be seen from the test results of Examples 2 to 3 in Table 1 that when the usage ratio of the collector sodium oleate and benzohydroxamic acid in flotation is 4 to 7:3, the TiO2 grade of the obtained ilmenite and the TiO2 grade of the titanium slag are both high; it can be seen from the test results of Comparative Examples 1 to 2 that when the usage ratio of the collector sodium oleate and benzohydroxamic acid in flotation exceeds 4 to 7:3, the TiO2 grade of the ilmenite concentrate and the titanium slag will be greatly reduced.

[0064] Comparative Example 3

[0065] This comparative example provides a method for separating low-grade titanium slag from titanium and iron and recovering titanium. Compared with Example 1, the difference is that no flotation is performed. The other steps are roughly the same as those in Example 1 and will not be repeated here.

[0066] Through mineralogical analysis, it was found that the TiO2 grade of the ilmenite in this comparative example was 45.75%; the TiO2 grade of the titanium slag was 76.37%.

[0067] Compared with the test results in Example 1, it can be seen that the TiO2 grade of the ilmenite and the titanium slag obtained without flotation operation are both reduced. Through analysis, increasing the amount of acid and alkali in this comparative example can improve the TiO2 grade. This is because some impurities in the ilmenite can also be removed by leaching. However, a significant increase in the amount of acid and alkali will increase the cost of mineral processing and accelerate equipment corrosion. It is also easy to cause environmental pollution and waste of resources.

[0068] In summary, the present application provides a method for separating low-grade titanium slag from titanium and iron and recovering titanium, which belongs to the technical field of titanium and iron resource recovery. The finely ground ilmenite is first subjected to flotation, acid leaching, and alkali leaching to remove impurity elements such as silicon, calcium, and magnesium in the ilmenite to obtain high-purity ilmenite; the ilmenite is then smelted to obtain molten iron and high-titanium slag containing trace impurities, and the TiO2 grade of the titanium slag reaches more than 90%. Compared with the titanium slag obtained by traditional smelting, the titanium slag obtained by the present invention has a very high content of titanium element and will not produce a large amount of titanium-silicon-calcium-magnesium symbiosis. The obtained titanium slag can be directly used for subsequent smelting of titanium metal, and first flotation and then acid leaching and alkali leaching are carried out, and the amount of acid and alkali used is greatly reduced. This process method can effectively solve the problem that the smelting titanium slag in the traditional industry cannot be treated, resulting in waste of titanium resources.

[0069] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for efficiently separating iron and titanium from low-grade ilmenite, comprising the following steps: S1, finely grinding the ilmenite after magnetic separation to obtain sample 1; S2, flotation the sample 1 to obtain ilmenite concentrate; S3, finely grinding the ilmenite concentrate to obtain sample 2; S4, acid leaching the sample 2, washing, filtering, and obtaining an acid leached concentrate; S5, alkali leaching the acid leached concentrate, filtering, and drying to obtain high-purity ilmenite; S6. Smelting the high-purity ilmenite to obtain molten iron and high-titanium slag.

2. The method for efficiently separating iron and titanium from low-grade ilmenite according to claim 1, characterized in that: In step S2, the flotation steps include preliminary desulfurization, primary roughing, and tertiary cleaning.

3. The method for efficiently separating iron and titanium from low-grade ilmenite according to claim 2, characterized in that: In the roughing and the fine selection, the collector is sodium oleate and benzohydroxamic acid in a mass ratio of 4 to 7:

3.

4. The method for efficiently separating iron and titanium from low-grade ilmenite according to claim 2, characterized in that: In the roughing and the fine separation, the adjusting agent is a sulfuric acid solution with a concentration of 5 wt%.

5. The method for efficiently separating iron and titanium from low-grade ilmenite according to claim 3, characterized in that: In the desulfurization, the collector is ethyl xanthate and the foaming agent is 2# oil.

6. The method for efficiently separating iron and titanium from low-grade ilmenite according to claim 1, characterized in that: In step S1, the fine grinding refers to the grinding fineness of -0.074 mm accounting for 60-75%.

7. The method for efficiently separating iron and titanium from low-grade ilmenite according to claim 1, characterized in that: In step S3, the fine grinding refers to a grinding fineness of -0.025mm≥80%.

8. The method for efficiently separating iron and titanium from low-grade ilmenite according to claim 1, characterized in that: In step S4, in the acid leaching, the mass ratio of the sample 2 to the acid solution is 10-40:3; the leaching temperature is 23-27°C; the stirring rate is 310r / min; the acid solution is a mixture of one or more acids selected from sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, and hydrofluoric acid; and the concentration of the acid solution is 8-20wt%.

9. The method for efficiently separating iron and titanium from low-grade ilmenite according to claim 1, characterized in that: In step S5, in the alkaline leaching, the mass ratio of the acid leaching concentrate to the alkaline solution is 10-40:3; the leaching temperature is 100-150°C; the stirring rate is 310r / min; the alkaline solution is a mixture of one or more alkalis selected from sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, and ammonia water; and the concentration of the alkaline solution is 8-20wt%.

10. The method for efficiently separating iron and titanium from low-grade ilmenite according to claim 1, characterized in that: In step S6, during the melting treatment, the melting temperature is 1400-2000°C.

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