Method for efficient separation of iron and titanium from low-grade ilmenite

Abstract

The application provides a method for efficiently separating iron and titanium from low-grade ilmenite, and belongs to the technical field of ilmenite resource recovery. In the application, after being finely ground, the ilmenite is first subjected to flotation, acid leaching and alkali leaching to remove impurity elements such as silicon, calcium and magnesium in the ilmenite, and high-purity ilmenite is obtained; then the ilmenite is subjected to smelting separation 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 application has a high content of titanium element, does not produce a large amount of titanium-silicon-calcium-magnesium symbiotic body, and can be directly used for subsequent smelting of metallic titanium. Moreover, the acid and alkali consumption is greatly reduced by first performing flotation and then acid leaching and alkali leaching. The process method can effectively solve the problem that the smelting titanium slag in the traditional industry cannot be treated, causing waste of titanium resources.

Description

TECHNICAL FIELD

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

[0002] Titanium and its derivatives are widely used in petrochemical industry, power industry, deep-sea shipbuilding, metallurgy, aerospace, coating, medical treatment and catalysis, etc. It is an important high-tech mineral for strategic emerging industries and plays a very important role in future scientific and technological development. The mineral sources of titanium mainly include ilmenite and rutile. However, the reserves of rutile which is easy to utilize in China are less, and the ilmenite which is difficult to utilize is mainly used. Therefore, the development and utilization of ilmenite is of great importance for the guarantee of titanium resources.

[0003] Ilmenite is a symbiotic complex ore of iron, titanium, calcium, magnesium, silicon and other elements, which is difficult to utilize. At present, the smelting process commonly used for smelting ilmenite causes most of the titanium in ilmenite to enter the slag, and it is difficult and costly to recover titanium from the slag, resulting in a large amount of titanium resources being lost.

[0004] In view of the technical defects of the traditional ironmaking process, there are a large amount of impurity elements such as calcium, magnesium and silicon in the titanium slag after smelting, which will produce a large amount of titanium-silicon-calcium-magnesium symbiotic body. These symbiotic bodies cause the titanium metal to be tightly combined with other impurity metals, greatly increasing the difficulty of subsequent separation of metallic titanium and greatly increasing the cost, resulting in great waste of titanium resources.

[0005] Therefore, it is necessary to provide a method for efficiently utilizing smelted titanium slag. SUMMARY

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

[0007] The present application provides a method for separating and recovering titanium from low-grade ilmenite slag, characterized in that it comprises the following steps:

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

[0009] S2, floating the sample one to obtain ilmenite concentrate;

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

[0011] S4, acid leaching, washing and filtering the sample two to obtain acid leaching concentrate;

[0012] S5, the acid leaching concentrate is subjected to alkali leaching, filtration, and drying to obtain high-purity ilmenite;

[0013] S6, the high-purity ilmenite is subjected to smelting separation treatment to obtain molten iron and high-titanium slag.

[0014] In the technical scheme of the embodiment, the ilmenite after fine grinding is subjected to flotation, acid leaching, and alkali leaching to remove impurity elements such as silicon, calcium, and magnesium in the ilmenite, and high-purity ilmenite is obtained; the ilmenite is then subjected to smelting separation 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 application has a high content of titanium elements, and a large amount of titanium-silicon-calcium-magnesium symbiotic body is not generated, the titanium slag can be directly used for subsequent smelting of metallic titanium, and the acid and alkali consumption is greatly reduced by first performing flotation and then acid leaching and alkali leaching. The process method can effectively solve the problem of waste of titanium resources caused by the fact that the smelting titanium slag in the traditional industry cannot be treated.

[0015] In some embodiments, in step S1, fine grinding refers to a grinding fineness of 60-75% of -0.074 mm.

[0016] In the embodiment, the ilmenite after magnetic separation is finely ground to obtain sample one for mineral separation.

[0017] In some embodiments, in step S2, the flotation step includes pre-desulfurization, one roughing, and three cleaning; in the desulfurization, the collector is ethyl xanthate, and the frother is 2# oil; in the roughing and cleaning, the regulator is a 5wt% sulfuric acid solution; and the collector is sodium oleate and benzyloxamic acid in a mass ratio of 4-7:3.

[0018] In the embodiment, the ilmenite containing a small amount of calcium, magnesium, and silicon impurities is obtained by pre-flotation to remove sulfide ore and then by one roughing and three cleaning flotation process.

[0019] In some embodiments, in step S3, fine grinding refers to a grinding fineness of -0.025 mm≥80%.

[0020] In the embodiment, the ilmenite concentrate is finely ground to obtain sample two for subsequent acid leaching.

[0021] In some embodiments, in step S4, in the acid leaching, the mass ratio of sample two to the acid solution is 10-40:3; the leaching temperature is 23-27℃; 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 8-20wt%.

[0022] In the embodiment, the calcium, magnesium, and other impurity elements in sample two are dissolved by acid leaching.

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

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

[0025] The above description is only a summary of the technical solutions of the present application. In order to more clearly understand the technical means of the present application, the following specific embodiments of the present application can be implemented according to the content of the specification, and in order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the present application, the following will briefly introduce the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creating any creative labor.

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

[0028] The embodiments of the technical solutions of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, but cannot limit the protection scope of the present application.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0030] In this paper, the phrase "embodiment" means that the specific features, structures or properties described in conjunction with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor is it a separate or alternative embodiment independent of or alternative to other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0031] In order to solve the problem that in the smelting process commonly used in the prior art for smelting ilmenite, most of titanium in the ilmenite enters into the slag, it is difficult to recover titanium from the slag, and the cost is high, and a large amount of titanium resources is lost, the application provides a method for separating and recovering titanium from low-grade titanium slag. The application removes the impurity elements such as silicon, calcium and magnesium in the ilmenite by first subjecting the ilmenite after fine grinding to flotation, acid leaching and alkali leaching, to obtain high-purity ilmenite; and then subjecting the ilmenite to melting separation treatment to obtain molten iron and high-titanium slag containing trace impurities, the TiO2 grade of the titanium slag reaches more than 90%. Compared with the titanium slag obtained by traditional smelting, the content of titanium element in the titanium slag obtained by the application is very high, and a large amount of titanium-silicon-calcium-magnesium symbiotic body will not be produced, the obtained titanium slag can be directly used for subsequent smelting of metallic titanium, and the acid and alkali consumption is greatly reduced by first performing flotation and then acid leaching and alkali leaching. The process method can effectively solve the problem that the smelting titanium slag in the traditional industry cannot be treated, causing waste of titanium resources.

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

[0033] S1, fine grinding the ilmenite after magnetic separation to obtain sample one;

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

[0035] S3, fine grinding the ilmenite concentrate to obtain sample two;

[0036] S4, subjecting the sample two to acid leaching, rinsing, and filtering to obtain acid leaching concentrate;

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

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

[0039] In the technical scheme of the application, the ilmenite after fine grinding is first subjected to flotation, acid leaching and alkali leaching to remove the impurity elements such as silicon, calcium and magnesium in the ilmenite, to obtain high-purity ilmenite; and then the ilmenite is subjected to melting separation treatment to obtain molten iron and high-titanium slag containing trace impurities, the TiO2 grade of the titanium slag reaches more than 90%. Compared with the titanium slag obtained by traditional smelting, the content of titanium element in the titanium slag obtained by the application is very high, and a large amount of titanium-silicon-calcium-magnesium symbiotic body will not be produced, the obtained titanium slag can be directly used for subsequent smelting of metallic titanium, and the acid and alkali consumption is greatly reduced by first performing flotation and then acid leaching and alkali leaching. The process method can effectively solve the problem that the smelting titanium slag in the traditional industry cannot be treated, causing waste of titanium resources.

[0040] Further, in some embodiments, in step S1, the fine grinding is to reach a grinding fineness of 60-75% passing 0.074 mm.

[0041] In the technical scheme of the embodiments of the present application, the ilmenite after magnetic separation is ground to obtain sample one for mineral processing.

[0042] Further, in some embodiments, in step S2, the step of flotation includes pre-desulfurization, one roughing and three cleaning; in the desulfurization, the collector is ethyl xanthate, and the frother is 2# oil; in the roughing and cleaning, the regulator is a 5wt% sulfuric acid solution; the collector is sodium oleate and carbohydroxamic acid with a mass ratio of 4-7:3.

[0043] In the technical scheme of the embodiments 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 by the flotation process of one roughing and three cleaning.

[0044] Further, in some embodiments, in step S3, the fine grinding is to reach a grinding fineness of 80% passing 0.025 mm.

[0045] In the technical scheme of the embodiments of the present application, the ilmenite concentrate is ground to obtain sample two for subsequent acid leaching.

[0046] Further, in some embodiments, in step S4, in the acid leaching, the mass ratio of sample two and the acid solution is 10-40:3; the leaching temperature is 23-27°C; the stirring rate is 310 r / min; the leaching time is 50-100 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%.

[0047] In the technical scheme of the embodiments of the present application, the calcium, magnesium and other impurity elements in sample two are dissolved by acid leaching.

[0048] Further, in some embodiments, in step S5, in the alkali leaching, the mass ratio of the acid leaching concentrate and the alkali solution is 10-40:3; the leaching temperature is 100-150°C; the stirring rate is 310 r / min; the leaching time is 100-120 min; the alkali 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 alkali solution is 8-20wt%.

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

[0050] Further, in some embodiments, in step S6, in the smelting treatment, the temperature of smelting is 1400-2000°C.

[0051] In the technical scheme of the embodiment of the present application, iron and titanium are separated by the melting separation 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 used to explain the present application, and cannot be understood as limiting the present application. If a specific technology or condition is not specified in the embodiments, the technology or condition described in the literature in the art or according to the product manual is used. If the manufacturer of the reagent or instrument is not specified, it is a conventional product that can be obtained from the market.

[0053] Embodiment 1

[0054] The embodiment provides a method for separating ilmenite from low-grade titanium slag and recovering titanium, and a process flow chart thereof is shown as Figure 1 The embodiment provides a method for separating ilmenite from low-grade titanium slag and recovering titanium, and a process flow chart thereof is shown as

[0055] The ilmenite after magnetic separation is finely ground to 67% of -0.074 mm, and then water is added to a pulp concentration of 33%; the pulp is added to an XFD-1L type flotation machine, and 400 g / t of ethyl xanthate and 28 g / t of 2# oil are added for flotation; after the flotation is completed, 1000 g / t of sulfuric acid, 900 g / t of sodium oleate and 500 g / t of benzohydroxamic acid are continuously added to the flotation tank for one roughing and three cleaning to obtain ilmenite concentrate; the obtained ilmenite concentrate is finely ground to 85% of -0.025 mm; the flotation concentrate and 200 g / t of hydrochloric acid solution with a concentration of 10 wt% are added to a reaction kettle, and the reaction is carried out at 25 DEG C and a stirring speed of 310 r / min for 100 minutes, and then filtration is performed to obtain an acid leaching concentrate; the acid leaching concentrate and 200 g / t of sodium hydroxide solution with a concentration of 10 wt% are added to a reaction kettle, and the reaction is carried out at 100 DEG C and a stirring speed of 310 r / min for 120 minutes, and then filtration is performed to obtain high-purity ilmenite; the high-purity ilmenite is calcined in an electric furnace at 1600 DEG C to obtain high-titanium slag.

[0056] Through mineralogical analysis, it is found that the ilmenite TiO2 grade in the embodiment is 48.34%, and the titanium slag TiO2 grade is 90%.

[0057] Embodiments 2-3 and Comparative Examples 1-2

[0058] Embodiments 2-3 and Comparative Examples 1-2 respectively provide a method for separating ilmenite from low-grade titanium slag and recovering titanium, and compared with Embodiment 1, the difference lies in that the proportion of the use amount of the collectors sodium oleate and benzohydroxamic acid in the flotation is different, and the other steps are substantially the same as those of Embodiment 1, which will not be described herein again.

[0059] The specific use amount of the collectors sodium oleate and benzohydroxamic acid in Embodiments 2-3 and Comparative Examples 1-2 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 2-3 and comparative examples 1-2

[0061]

[0062]

[0063] As can be seen from the test results of examples 2-3 in table 1, when the dosage ratio of the collector sodium oleate and benzohydroxamic acid in the flotation is 4-7:3, the ilmenite TiO2 grade and the titanium slag TiO2 grade obtained are both high; as can be seen from the test results of comparative examples 1-2, when the dosage ratio of the collector sodium oleate and benzohydroxamic acid in the flotation exceeds 4-7:3, 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 and recovering titanium from low-grade titanium slag, which is different from example 1 in that it does not undergo flotation, and the other steps are substantially the same as those of example 1, which will not be repeated here.

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

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

[0068] In summary, the present application provides a method for separating and recovering titanium from low-grade titanium slag, which belongs to the technical field of ilmenite resource recovery. By first subjecting the finely ground ilmenite to flotation, acid leaching and alkali leaching, the silicon, calcium, magnesium and other impurity elements in the ilmenite are removed to obtain high-purity ilmenite; then the ilmenite is subjected to smelting separation to obtain molten iron and high-titanium slag containing trace impurities, and the TiO2 grade of the slag is more than 90%. Compared with the titanium slag obtained by traditional smelting, the titanium slag obtained by the present application has a high content of titanium element, does not produce a large amount of titanium-silicon-calcium-magnesium symbiotic body, and can be directly used for subsequent smelting of metallic titanium. Moreover, the acid and alkali dosage is greatly reduced by first performing flotation and then acid leaching and alkali leaching. This process can effectively solve the problem of waste of titanium resources caused by the inability to process smelting titanium slag in the traditional industry.

[0069] Note that the present application is not limited to the above-described embodiments. The above-described embodiments are merely examples, and embodiments having substantially the same configuration, function, and effect as the technical idea of the present application are included in the technical scope of the present application. Furthermore, other modes constructed by applying various modifications to the embodiments, or by combining part of the configurations of the embodiments, which can be conceived by those skilled in the art, without departing from the spirit of the present application, are also included in the scope of the present application.

Claims

1. A method for efficient separation of iron and titanium from low-grade ilmenite, comprising the following steps: S1, finely grinding ilmenite after magnetic separation to obtain sample one; S2, performing flotation on the sample one to obtain ilmenite concentrate; S3, finely grinding the ilmenite concentrate to obtain sample two; S4, performing acid leaching, rinsing, and filtering on the sample two to obtain acid leaching concentrate; S5, performing alkali leaching, filtering, and drying on the acid leaching concentrate to obtain high-purity ilmenite; S6, performing smelting treatment on the high-purity ilmenite to obtain molten iron and high-titanium slag; wherein the step of flotation comprises pre-desulfurization, one roughing, and three cleaning; in the roughing and the cleaning, the collector is sodium oleate and benzo-hydroxamic acid with a mass ratio of 4-7:

3.

2. The process for efficient separation of iron and titanium from low-grade ilmenite of claim 1, wherein, in the roughing and the cleaning, the regulator is a sulfuric acid solution with a concentration of 5wt%.

3. The process for efficient separation of iron and titanium from low-grade ilmenite of claim 1, wherein, in the desulfurization, the collector is ethyl xanthate, and the frother is 2# oil.

4. The process for efficient separation of iron and titanium from low-grade ilmenite of claim 1, wherein, in step S1, the fine grinding refers to a grinding fineness of 60-75% of -0.074mm.

5. The process for efficient separation of iron and titanium from low-grade ilmenite of claim 1, wherein, in step S3, the fine grinding refers to a grinding fineness of -0.025mm≥80%.

6. The process for efficient separation of iron and titanium from low-grade ilmenite of claim 1, wherein, in step S4, in the acid leaching, the mass ratio of the sample two and the acid solution is 10-40:3, the leaching temperature is 23-27℃, 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%.

7. The process for efficient separation of iron and titanium from low-grade ilmenite of claim 1, wherein, in step S5, in the alkali leaching, the mass ratio of the acid leaching concentrate and the alkali solution is 10-40:3, the leaching temperature is 100-150℃, the stirring rate is 310r / min, the alkali 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 alkali solution is 8-20wt%.

8. The process for efficient separation of iron and titanium from low-grade ilmenite of claim 1, wherein, in step S6, in the smelting treatment, the smelting temperature is 1400-2000℃.

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