Method for recovering carbon, iron and titanium from leaching residues of molten salt chlorination waste salts and dust collection residues

Abstract

The present invention discloses a method for recovering carbon, iron, and titanium from the leaching residue of molten salt chlorination waste salt and dust collection slag. The method comprises the following steps: leaching the soluble components in the molten salt chlorination waste salt and dust collection slag with a solution at a predetermined liquid-solid ratio and washing and filtering to obtain a leaching residue; performing carbon separation on the leaching residue with a collector and a foaming agent to obtain carbon concentrate and tailings; and performing titanium separation and iron separation on the tailings by means of a hydrocyclone to obtain enriched materials of titanium and iron respectively. The method disclosed by the present invention realizes the treatment of chlorination waste salt and dust collection slag, and avoids the environmental pollution caused by the waste stacking or landfill of molten salt chlorination waste salt and dust collection slag in the wild. The method provided by the present invention is convenient to operate, has a simple process flow, low production cost, and is easy to realize industrialization.

Description

Technical Field

[0001] The present invention relates to the technical fields of resource recovery and environmental protection, and particularly to a method for recovering carbon, iron, and titanium from the leaching residues of molten salt chlorination waste salts and dust collection residues. Background Art

[0002] At present, the main methods for producing titanium tetrachloride industrially are molten salt chlorination and fluidized bed chlorination. Fluidized bed chlorination has high requirements for the quality of titanium slag raw materials. For example, it requires that the calcium and magnesium contents in the titanium slag raw materials are <1.0%. This method has little pollution. Molten salt chlorination has low requirements for raw materials and can process titanium slag raw materials with high calcium and magnesium oxide contents. The titanium tetrachloride produced by molten salt chlorination accounts for 40% of the global annual output of titanium tetrachloride. However, the disadvantage of this method is that it generates a large amount of waste molten salt and dust collection residues. The main components of the waste molten salt and dust collection residues are chlorides. If not properly treated, chloride volatilization and hydrolysis will occur. During the process of discharging the waste molten salt and dust collection residues, a large amount of chloride-containing soot will be generated, seriously polluting the environment. At present, there is no economically effective treatment technology for this pollutant, and it is generally treated by mixing with lime and stacking in the wasteland or landfilling in a professional slag yard.

[0003] However, the chlorination waste salts and dust collection residues generated during the production process of molten salt chlorination contain certain carbon, iron, and titanium with comprehensive recovery value. The above treatment methods not only waste valuable resources but also cause environmental pollution to a certain extent.

[0004] Therefore, an effective treatment method is needed to recover valuable resources from the leaching residues of chlorination waste salts and dust collection residues and produce good environmental protection benefits. Summary of the Invention

[0005] To solve the above technical problems, the present invention proposes a method for recovering carbon, iron, and titanium from the leaching residues of molten salt chlorination waste salts and dust collection residues, which can solve the technical problems of waste of valuable resources and environmental pollution caused by the existing methods for treating molten salt chlorination waste salts and dust collection residues.

[0006] An embodiment of the present invention discloses a method for recovering carbon, iron, and titanium from the leaching residues of molten salt chlorination waste salts and dust collection residues, including the following steps:

[0007] Leach the soluble components in the molten salt chlorination waste salts and dust collection residues with a solution at a predetermined liquid-solid ratio, wash and filter to obtain leaching residues;

[0008] Select carbon from the leaching residues with a collector and a frother to obtain carbon concentrate and tailings;

[0009] Use the method of hydrocyclone to select titanium and iron from the tailings to obtain enriched materials of titanium and iron respectively.

[0010] According to an embodiment of the present invention, the mass content of soluble components in the molten salt chlorination waste salt and dust collection slag is 70% to 90%. The pH of the solution used for leaching the soluble components in the molten salt chlorination waste salt and dust collection slag is ≤ 8.5. The predetermined liquid-solid ratio is the ratio of the volume of the solution used for leaching to the mass of the molten salt chlorination waste salt and dust collection slag, and the predetermined liquid-solid ratio is (1 to 10):1. The leaching time is 1 to 5 hours, and the leaching residue needs to be washed until the mass content of salt is < 0.05%.

[0011] According to an embodiment of the present invention, the solution is any one of water, a weakly alkaline solution, and an acidic solution.

[0012] According to an embodiment of the present invention, by mass percentage, the carbon content in the leaching residue is ≥ 3%, the iron content is ≥ 4%, and the titanium content is ≥ 1%.

[0013] According to an embodiment of the present invention, before carbon separation, the leaching residue is pulped, the pulp concentration is adjusted to 25% to 40%, and then the collector and the foaming agent are added for carbon separation.

[0014] According to an embodiment of the present invention, the total dosage of the collector is 450 - 850 g / t, and the total dosage of the foaming agent is 75 - 130 g / t.

[0015] According to an embodiment of the present invention, the collector is any one of kerosene, light diesel oil, shale diesel oil, gas oil, PYP - 01, FS - 201, FS - 202, BET, ZFC, WL, ZNX, ECS, and the foaming agent is any one of sec - octanol, miscellaneous alcohols, mixed alcohols, GF oil, miscellaneous alcohol oil, ester oil, No. 4 oil, HC - type foaming agent, X - 316 foaming agent, PYQ - 01.

[0016] According to an embodiment of the present invention, before titanium and iron separation from the tail slag by the method of hydrocyclone, the tail slag is pulped, and the pulp concentration is controlled at 10% to 30%.

[0017] According to an embodiment of the present invention, the model of the hydrocyclone used in the hydrocyclone method is FX150 type, the feed pressure is 0.17 - 0.18 MPa, the bottom outlet diameter of the hydrocyclone is 18 - 20 mm, and the overflow outlet diameter is 44 - 45 mm.

[0018] Adopting the above technical solution, the present invention has at least the following beneficial effects:

[0019] The present invention provides a method for recovering carbon, iron, and titanium from the leaching residues of molten salt chlorination waste salts and dust collection residues. The soluble components in the molten salt chlorination waste salts and dust collection residues are leached with a solution to obtain leaching residues. The soluble components obtained by leaching can be used to recover the valuable components contained therein. Subsequently, a carbon collector and a foaming agent are used to perform carbon separation on the leaching residues to obtain carbon concentrate, and then a hydrocyclone method is used to perform titanium separation and iron separation on the tailings after carbon separation to obtain enriched materials of titanium and iron, realizing the recovery of valuable resources carbon, iron, and titanium in the molten salt chlorination waste salts and dust collection residues, avoiding the waste of valuable resources, and at the same time realizing the treatment of the molten salt chlorination waste salts and dust collection residues, avoiding the environmental pollution caused by the waste stacking in the wild or landfill in a slag yard of the molten salt chlorination waste salts and dust collection residues. Moreover, the method provided by the present invention is convenient to operate, has a simple process flow, low production costs, and is easy to realize industrialization. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 It is a process flow diagram of a method for recovering carbon, iron, and titanium from the leaching residues of molten salt chlorination waste salts and dust collection residues disclosed in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] To make the objectives, technical solutions, and advantages of the present invention clearer, the following further describes the embodiments of the present invention in detail with reference to specific embodiments and the accompanying drawings.

[0023] It should be noted that all the expressions using "first" and "second" in the embodiments of the present invention are used to distinguish two non-identical entities or non-identical parameters with the same name. It can be seen that "first" and "second" are only for the convenience of expression and should not be construed as a limitation on the embodiments of the present invention. This will not be elaborated in the subsequent embodiments one by one.

[0024] As Figure 1 shown, an embodiment of the present invention discloses a method for recovering carbon, iron, and titanium from the leaching residues of molten salt chlorination waste salts and dust collection residues, including the following steps:

[0025] Leach the soluble components in the molten salt chlorination waste salts and dust collection residues with a solution at a predetermined liquid-solid ratio and wash and filter to obtain leaching residues;

[0026] Perform carbon separation on the leaching residues with a carbon collector and a foaming agent to obtain carbon concentrate and tailings;

[0027] The method of using hydrocyclone is adopted to separate titanium and iron from the tailings, and enriched materials of titanium and iron are obtained respectively.

[0028] In the above embodiments, in addition to treating the leaching residue to recover carbon, iron and titanium, the soluble components in the leaching can also be treated to recover the valuable components contained therein, realizing the recovery of valuable resources in the molten salt chlorination waste salt and the dust collection slag, and avoiding the environmental pollution caused by the waste stacking or landfill of the molten salt chlorination waste salt and the dust collection slag in the wasteland.

[0029] In some embodiments, the mass content of the soluble components in the molten salt chlorination waste salt and the dust collection slag is 70% - 90%, the pH of the solution used for leaching the soluble components in the molten salt chlorination waste salt and the dust collection slag is ≤ 8.5, the predetermined liquid-solid ratio is the ratio of the volume of the solution used for leaching to the mass of the molten salt chlorination waste salt and the dust collection slag, the predetermined liquid-solid ratio is (1 - 10):1, the leaching time is 1 - 5 h, and the leaching residue needs to be washed until the mass content of the salt is < 0.05%.

[0030] In some embodiments, the solution is any one of water, weak alkaline solution and acidic solution.

[0031] In some embodiments, by mass percentage, the carbon content in the leaching residue is ≥ 3%, the iron content is ≥ 4%, and the titanium content is ≥ 1%.

[0032] In some embodiments, before carbon separation, the leaching residue is slurried, the slurry concentration is adjusted to 25% - 40%, and then a collector and a frother are added for carbon separation.

[0033] In some embodiments, the total dosage of the collector is 450 - 850 g / t, and the total dosage of the frother is 75 - 130 g / t.

[0034] In some embodiments, the collector is any one of kerosene, light diesel oil, shale diesel oil, gas oil, PYP - 01, FS - 201, FS - 202, BET, ZFC, WL, ZNX, ECS, and the frother is any one of sec - octanol, miscellaneous alcohols, mixed alcohols, GF oil, miscellaneous alcohol oil, ester oil, No. 4 oil, HC type frother, X - 316 frother, PYQ - 01.

[0035] In some embodiments, before separating titanium and iron from the tailings by using the hydrocyclone method, the tailings are slurried first, and the slurry concentration is controlled at 10% - 30%.

[0036] In some embodiments, the model of the hydrocyclone used in the hydrocyclone method is FX150, the feed pressure is 0.17 - 0.18 MPa, the diameter of the underflow port of the hydrocyclone is 18 - 20 mm, and the diameter of the overflow port is 44 - 45 mm.

[0037] The method for recovering carbon, iron, and titanium from the leaching residue of molten salt chlorination waste salt and dust collection slag disclosed in the embodiments of the present invention will be further described below in conjunction with the embodiments.

[0038] Example 1

[0039] In this example, the molten salt chlorination waste salt obtained from the molten salt chlorination production line of Pangang is selected. The specific steps for recovering carbon, iron, and titanium from the molten salt chlorination waste salt in this example are as follows:

[0040] Step 1: The soluble components in the molten salt chlorination waste salt account for 85% of the total mass. Using water as the leaching solution, the leaching liquid-solid ratio (the volume of water used for leaching to the mass of the molten salt chlorination waste salt) is 3:1, the leaching time is 3 h, the leaching residue is washed with water until the salt content is 0.02% (mass percentage), and the carbon, iron, and titanium contents in the washed leaching residue are 12.8%, 13.5%, and 12.4% respectively;

[0041] Step 2: Pulp the leaching residue, adjust the pulp concentration to 36%, add the collector FS-201 while stirring, with a dosage of 650 g / t, and the foaming agent X-316, with a dosage of 110 g / t, to fully mix the reagent with the pulp, and scrape off the foam to obtain the carbon concentrate;

[0042] Step 3: Pulp the tailings after carbon separation, control the pulp concentration at 20%, select the FX150 type hydrocyclone for treatment, the feed pressure is 0.18 MPa, the bottom outlet diameter and the overflow outlet diameter of the hydrocyclone are 20 mm and 45 mm respectively, the obtained underflow is the enriched material of titanium, and the obtained overflow is the enriched material of iron.

[0043] In the above Example 1, through analysis and calculation, the final grade of the obtained carbon concentrate is 86.9%, and the recovery rate is 95.7%; the iron content in the obtained iron-rich material is 28.9%, and the iron recovery rate is 88.5%; the titanium content in the obtained titanium-rich material is 29.8%, converted to the TiO2 content is 49.7%, and the titanium recovery rate is 83.1%.

[0044] Example 2

[0045] In this example, the molten salt chlorination dust collection slag obtained from the molten salt chlorination production line of Pangang is selected. The specific steps for recovering carbon, iron, and titanium from the molten salt chlorination dust collection slag in this example are as follows:

[0046] Step 1: The soluble components in the molten salt chlorination dust collection slag account for 90% of the total mass. Using water as the leaching solution, the leaching liquid-solid ratio (the volume of water used for leaching to the mass of the molten salt chlorination dust collection slag) is 4:1, the leaching time is 3 h, the leaching residue is washed with water until the salt content is 0.04% (mass percentage), and the carbon, iron, and titanium contents in the washed leaching residue are 11.7%, 9.8%, and 6.3% respectively;

[0047] Step 2: Pulp the leaching residue, adjust the pulp concentration to 36%, add collector FS-201 while stirring, with a dosage of 650 g / t, and frother X-316, with a dosage of 100 g / t, to fully mix the reagent with the pulp. The scraped foam is the carbon concentrate.

[0048] Step 3: Pulp the tailings after carbon separation, control the pulp concentration at 22%, use FX150 type hydrocyclone for treatment, with a feed pressure of 0.17 MPa. The diameters of the sand settling nozzle and the overflow port of the hydrocyclone are 18 mm and 45 mm respectively. The obtained underflow is the titanium-enriched material, and the obtained overflow is the iron-enriched material.

[0049] In the above Example 2, through analysis and calculation, the final grade of the carbon concentrate obtained is 87.3%, and the recovery rate is 94.9%; the iron content in the obtained iron-rich material is 24.3%, and the iron recovery rate is 86.6%; the titanium content in the obtained titanium-rich material is 24.6%, and when converted to TiO2 content, it is 41.1%, and the titanium recovery rate is 80.2%.

[0050] From the data of the valuable resources obtained in the above Example 1 and Example 2, it can be seen that through the method disclosed in the embodiments of the present invention, the recovery rate of carbon recovered from the leaching residue of molten salt chlorination waste salt and dust collection slag reaches more than 94.0%, the recovery rate of the recovered iron reaches more than 85.0%, and the recovery rate of the recovered titanium reaches more than 80.0%. Through the method disclosed in the embodiments of the present invention, the recovery of valuable resources in molten salt chlorination waste salt and dust collection slag is realized.

[0051] In summary, in the embodiments of the present invention, the soluble components in the molten salt chlorination waste salt and dust collection slag are leached with a solution to obtain a leaching residue, and the leached soluble components are then used to recover the valuable components contained therein. Then, a collector and a frother are used to separate carbon from the leaching residue to obtain a carbon concentrate, and a hydrocyclone method is used to separate titanium and iron from the tailings after carbon separation to obtain titanium- and iron-enriched materials, realizing the recovery of valuable resources carbon, iron, and titanium in the chlorination waste salt and dust collection slag, avoiding the waste of valuable resources, and at the same time realizing the treatment of the chlorination waste salt and dust collection slag, avoiding the environmental pollution caused by the waste stacking or landfill of the molten salt chlorination waste salt and dust collection slag in the wild. Moreover, the method provided by the present invention is convenient to operate, has a simple process flow, low production cost, and is easy to realize industrialization.

[0052] It should be particularly noted that each component or step in the above various embodiments can be cross-interchanged, replaced, added, or deleted. Therefore, the combinations formed by these reasonable permutations and combinations should also fall within the protection scope of the present invention, and the protection scope of the present invention should not be limited to the above embodiments.

[0053] The foregoing are exemplary embodiments disclosed by the present invention. The order in which the above-described embodiments of the present invention are disclosed is for description purposes only and does not represent the superiority or inferiority of the embodiments. However, it should be noted that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples. Without departing from the scope defined by the claims, various changes and modifications can be made. The functions, steps, and / or actions of the method claims according to the disclosed embodiments herein need not be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or claimed in individual form, they can also be understood as plural unless explicitly limited to the singular form.

[0054] Those of ordinary skill in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other variations in different aspects of the embodiments of the present invention as described above, and they are not provided in detail for the sake of brevity. Therefore, any omission, modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the present invention shall be included within the protection scope of the embodiments of the present invention.

Claims

1. A method for recovering carbon, iron, and titanium from the leaching residue of molten salt chlorination waste salt and dust collection slag, characterized in that, It includes the following steps: Leach the soluble components in the molten salt chlorination waste salt and dust collection slag with a solution at a predetermined liquid-solid ratio, wash and filter to obtain leaching residues; Perform carbon separation on the leaching residues with a collector and a foaming agent to obtain carbon concentrate and tailings; Use the method of hydrocyclone to separate titanium and iron from the tailings to obtain enriched materials of titanium and iron respectively; Among them, the mass content of the soluble components in the molten salt chlorination waste salt and dust collection slag is 70% - 90%, the pH of the solution used for leaching the soluble components in the molten salt chlorination waste salt and dust collection slag is ≤ 8.5, the predetermined liquid-solid ratio is the ratio of the volume of the solution used for leaching to the mass of the molten salt chlorination waste salt and dust collection slag, the predetermined liquid-solid ratio is (1 - 10):1, the leaching time is 1 - 5h, and the leaching residues need to be washed until the mass content of salts < 0.05%; The solution is any one of water, a weakly alkaline solution, and an acidic solution; The collector is any one of kerosene, light diesel oil, shale diesel oil, gas oil, PYP - 01, FS - 201, FS - 202, BET, ZFC, WL, ZNX, ECS, and the foaming agent is any one of sec-octanol, miscellaneous alcohols, mixed alcohols, GF oil, miscellaneous alcohol oil, ester oil, No. 4 oil, HC type foaming agent, X - 316 foaming agent, PYQ - 01; 2. The method for recovering carbon, iron, and titanium from the leaching residue of molten salt chlorination waste salt and dust collection slag according to claim 1, characterized in that, By mass percentage, the carbon content in the leaching residues is ≥ 3%, the iron content is ≥ 4%, and the titanium content is ≥ 1%.

3. The method for recovering carbon, iron, and titanium from the leaching residue of molten salt chlorination waste salt and dust collection slag according to claim 1, characterized in that, It also includes that before carbon separation, the leaching residues are slurried, the slurry concentration is adjusted to 25% - 40%, and then the collector and the foaming agent are added for carbon separation.

4. The method for recovering carbon, iron, and titanium from the leaching residue of molten salt chlorination waste salt and dust collection slag according to claim 1, wherein, The total dosage of the collector is 450 - 850g / t, and the total dosage of the foaming agent is 75 - 130g / t.

5. The method for recovering carbon, iron, and titanium from the leaching residue of molten salt chlorination waste salt and dust collection slag according to claim 1, characterized in that, It also includes that before separating titanium and iron from the tailings by the method of hydrocyclone, the tailings are slurried, and the slurry concentration is controlled at 10% - 30%.

6. The method for recovering carbon, iron, and titanium from the leaching residue of molten salt chlorination waste salt and dust collection slag according to claim 1, characterized in that, In the method of hydrocyclone, the model of the hydrocyclone used is FX150, the feed pressure is 0.17 - 0.18MPa, the diameter of the underflow port of the hydrocyclone is 18 - 20mm, and the diameter of the overflow port is 44 - 45mm.

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