Method for comprehensive recovery of reduced titanium dust collecting ash

Abstract

This invention relates to the field of solid waste treatment technology, specifically to a method for the comprehensive recycling and utilization of reduced titanium dust. The method includes: mixing a slurry containing reduced titanium dust with flotation reagents and performing a first roughing flotation and a first scavenging flotation to obtain a first scavenging flotation concentrate and a first scavenging flotation tailings; mixing the first scavenging flotation concentrate with flotation reagents for a first cleaning flotation, and then mixing it with the first roughing flotation concentrate to obtain activated carbon; mixing the first scavenging flotation tailings with flotation reagents and performing a second roughing flotation to obtain a second roughing flotation concentrate; mixing the second roughing flotation concentrate with flotation reagents and performing a second cleaning flotation to obtain a second cleaned flotation concentrate; and finally, after solid-liquid separation, obtaining titanium concentrate. This method can efficiently recover and enrich titanium concentrate and activated carbon from reduced titanium dust, achieving full recycling of waste by-products.

Description

Technical Field

[0001] This invention relates to the field of solid waste treatment technology, and more specifically, to a method for the comprehensive recycling and utilization of reduced titanium dust. Background Technology

[0002] Reduced titanium is a reduction product obtained by directly reducing most of the iron oxides in ilmenite to metallic iron using a direct reduction process. With the rapid development of the titanium dioxide and titanium metal industries, reduced titanium is currently mainly used for the preparation of titanium-rich materials. In China, the chloride process titanium dioxide and sponge titanium industry chain produces titanium-rich materials by smelting titanium slag in electric furnaces or by preparing synthetic rutile through acid leaching.

[0003] The production process of reduced titanium mainly involves reacting a reducing agent with titanium concentrate at high temperatures through a rotary kiln or other reduction equipment. In large-scale industrial production equipment, air needs to be introduced to supplement oxygen and ensure that the reduction equipment is kept at a high temperature. Inevitably, some fine materials will be carried out in the exhaust gas. These fine materials are mainly composed of fine-grained reduced titanium, titanium concentrate, and reducing agent.

[0004] Common reducing agents include coal, such as bituminous coal, anthracite, semi-coke, and lignite. After a high-temperature reduction reaction, the volatile matter in this reducing agent is removed, yielding coal-based activated carbon. Common phases in titanium concentrate include ilmenite, rutile, quartz, and silicate impurities. Therefore, the main phases in reduced titanium dust are reduced titanium, ilmenite, rutile, quartz, activated carbon, and silicates. Among these components, reduced titanium, ilmenite, rutile, and activated carbon all possess high economic value. However, currently, reduced titanium dust is typically sold directly to activated carbon manufacturers as an intermediate product, which means it doesn't generate sufficient economic value and doesn't maximize resource utilization and recycling.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a method for the comprehensive recycling and utilization of reduced titanium dioxide dust. This method can efficiently recover and enrich titanium concentrate and activated carbon from reduced titanium dioxide dust, achieving full recycling and utilization of waste by-products. It solves the problems of low economic value and low resource utilization rate in existing technologies where reduced titanium dioxide dust is directly sold as an intermediate product of activated carbon.

[0007] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0008] This invention provides a method for the comprehensive recycling and utilization of reduced titanium dust, comprising the following steps:

[0009] (a) The slurry containing reduced titanium dust is mixed with activated carbon flotation reagent and subjected to the first flotation roughing to obtain the first flotation roughing concentrate and the first flotation roughing tailings.

[0010] (b) The first flotation rougher tailings are mixed with the activated carbon flotation reagent and subjected to the first flotation scavenging to obtain the first flotation scavenging concentrate and the first flotation scavenging tailings.

[0011] (c) The first flotation scavenging concentrate is mixed with the activated carbon flotation reagent and subjected to a first flotation cleaning process to obtain a first flotation clean concentrate and a first flotation clean tailings; the first flotation clean concentrate is mixed with the first flotation roughing concentrate and then subjected to solid-liquid separation to obtain activated carbon.

[0012] (d) The first flotation scavenging tailings are mixed with titanium concentrate flotation reagents and subjected to a second flotation roughing to obtain a second flotation roughing concentrate and a second flotation roughing tailings.

[0013] (e) The second flotation rougher concentrate is mixed with the titanium concentrate flotation reagent and subjected to a second flotation cleaning process to obtain a second flotation clean concentrate and a second flotation clean tailings; the second flotation clean concentrate is then subjected to solid-liquid separation to obtain titanium concentrate.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] (1) The method for comprehensive recycling of reduced titanium dust provided by the present invention can effectively separate activated carbon and titanium concentrate, achieving full recycling of waste by-products.

[0016] (2) The method for comprehensive recycling of reduced titanium dust provided by the present invention has high yield of activated carbon and titanium concentrate, and the activated carbon obtained has high adsorption effect and high grade of titanium concentrate.

[0017] (3) The method for comprehensive recycling of reduced titanium dust provided by the present invention has high raw material utilization rate, high resource utilization rate, and improved economic added value. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 The process flow diagram of the method for comprehensive recycling of reduced titanium dust provided by the present invention is shown. Detailed Implementation

[0020] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0021] Unless otherwise specified, the terms "comprising" and "including" as used in this invention can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0022] This invention provides a method for the comprehensive recycling and utilization of reduced titanium dust, see [link to relevant documentation]. Figure 1 The diagram shows the process flow chart of the comprehensive recycling method for reduced titanium dust, which specifically includes the following steps:

[0023] (a) The slurry containing reduced titanium dust is mixed evenly with activated carbon flotation reagent and subjected to the first flotation roughing to obtain the first flotation roughing concentrate and the first flotation roughing tailings.

[0024] In some specific implementations, reduced titanium dust refers to the fine material carried out by the exhaust gas generated during the production process of reduced titanium.

[0025] In some specific implementations, the main components of reduced titanium dust include reduced titanium, ilmenite, rutile, quartz, activated carbon, and silicates.

[0026] In some specific implementations, the reduced titanium dust is mixed with water and stirred evenly to obtain a slurry.

[0027] (b) The first flotation rougher tailings obtained in step (a) are mixed evenly with the activated carbon flotation reagent and subjected to the first flotation scavenging to obtain the first flotation scavenging concentrate and the first flotation scavenging tailings.

[0028] (c) The first flotation scavenging concentrate obtained in step (b) is mixed with the activated carbon flotation reagent and homogenized, and then subjected to the first flotation cleaning process to obtain the first flotation clean concentrate and the first flotation clean tailings. Then, the first flotation clean concentrate is mixed with the first flotation rougher concentrate obtained in step (a) and subjected to solid-liquid separation to obtain activated carbon.

[0029] (d) The first flotation scavenging tailings obtained in step (b) are mixed evenly with titanium concentrate flotation reagents, and then subjected to second flotation roughing to obtain second flotation roughing concentrate and second flotation roughing tailings.

[0030] (e) The second flotation rougher concentrate obtained in step (d) is mixed evenly with the titanium concentrate flotation reagent and subjected to a second flotation cleaning process to obtain a second flotation clean concentrate and a second flotation clean tailings; the second flotation clean concentrate is then subjected to solid-liquid separation to obtain titanium concentrate.

[0031] The method for comprehensive recycling of reduced titanium dust provided by this invention can separate activated carbon and titanium concentrate, achieving full recycling of waste by-products. Furthermore, this method has high yields of activated carbon and titanium concentrate, and the titanium concentrate grade is relatively high.

[0032] This invention, based on the fine particle size of the titanium dust, employs a flotation method suitable for fine-grained resource recovery. It recovers and reduces activated carbon and titanium concentrate from the titanium dust in stages, ensuring optimal separation of both and guaranteeing the titanium grade of the concentrate. Furthermore, considering the different properties of activated carbon and ilmenite, this invention uses different flotation reagents to perform multiple flotation processes on both, ensuring full recovery of both and improving the overall resource recovery rate.

[0033] In addition, the above methods have advantages such as simple process, high resource utilization and easy industrial production.

[0034] In some specific embodiments, in steps (a), (b), and (c), the activated carbon flotation reagent mainly consists of a first frother and a first collector in a mass ratio of 2–4:1–3. The mass ratio of the first frother to the first collector includes, but is not limited to, any one of 2:1, 3:1, 4:1, 2:2, 3:2, 4:2, 2:3, 3:3, or 4:3, or a range between any two.

[0035] In some specific embodiments, in steps (a), (b), and (c), the first foaming agent includes pine oil and / or 2-octanol; preferably pine oil.

[0036] In some specific implementations, in steps (a), (b), and (c), the first collector includes diesel oil and / or kerosene.

[0037] In some specific embodiments, in step (a), the mass fraction of reduced titanium dust in the slurry containing reduced titanium dust is 15% to 40%; including but not limited to any one of 15%, 20%, 25%, 30%, 35%, and 40%, or any range between two of them.

[0038] In some specific embodiments, in step (a), the mass ratio of the activated carbon flotation reagent to the reduced titanium dust in the slurry containing reduced titanium dust is 600-2000 g:1 t, including but not limited to any one of 600 g:1 t, 800 g:1 t, 1000 g:1 t, 1200 g:1 t, 1500 g:1 t, 1800 g:1 t, 2000 g:1 t, or any range between the two.

[0039] It is understandable that the mass of activated carbon flotation reagent required per ton of reduced titanium dust is 600–2000g.

[0040] In some specific embodiments, in step (b), the mass ratio of the activated carbon flotation reagent to the first flotation rougher tailings is 50-200 g: 1 t; including but not limited to any one of 50 g: 1 t, 80 g: 1 t, 100 g: 1 t, 130 g: 1 t, 150 g: 1 t, 180 g: 1 t, 200 g: 1 t or any range between two of them.

[0041] In some specific embodiments, in step (c), the mass ratio of the activated carbon flotation reagent to the first flotation scavenging concentrate is 50-200 g: 1 t, including but not limited to any one of 50 g: 1 t, 80 g: 1 t, 100 g: 1 t, 130 g: 1 t, 150 g: 1 t, 180 g: 1 t, 200 g: 1 t, or any range between the two.

[0042] In some specific embodiments, step (c) further includes a water washing and drying step after the solid-liquid separation. Preferably, the water washing is performed at least twice, and can also be performed three or four times.

[0043] In some specific embodiments, in step (d), before mixing, the first flotation scavenging tailings are subjected to solid-liquid separation and water washing, and then mixed evenly with water to form a slurry; then the slurry is mixed with the titanium concentrate flotation reagent and subjected to the second flotation roughing.

[0044] In some specific embodiments, the mass fraction of the first flotation scavenging tailings in the slurry is 30% to 50%; including but not limited to any one of 30%, 32%, 35%, 40%, 45%, 48%, 50% or any range between two.

[0045] In some specific implementations, the pH of the slurry is 4 to 6, including but not limited to any one of 4, 4.3, 4.5, 4.8, 5.0, 5.3, 5.5, 5.8, and 6, or a range between any two.

[0046] In some specific embodiments, the pH of the slurry is adjusted to 4-6 by adding dilute sulfuric acid.

[0047] In some specific implementations, in steps (d) and (e), the titanium concentrate flotation reagent includes a second frother and a second collector.

[0048] In some specific embodiments, the second foaming agent comprises pine oil and / or 2-octanol; preferably pine oil.

[0049] In some specific embodiments, the second collector includes salicylic acid and / or sodium dithiocarbonate.

[0050] In some specific implementations, in step (d), the mass ratio of the second frother to the first flotation scavenging tailings is 600-1000 g: 1 t; including but not limited to any one of 600 g: 1 t, 700 g: 1 t, 800 g: 1 t, 900 g: 1 t, 1000 g: 1 t or any range between the two.

[0051] In some specific embodiments, in step (d), the mass ratio of the second collector to the first flotation scavenging tailings is 800-1600 g:1 t; including but not limited to any one of 800 g:1 t, 900 g:1 t, 1000 g:1 t, 1200 g:1 t, 1400 g:1 t, 1500 g:1 t, 1600 g:1 t or any range between the two.

[0052] In some specific embodiments, in step (e), the mass ratio of the second frother to the second flotation rougher concentrate is 50-150 g:1 t; including but not limited to any one of 50 g:1 t, 80 g:1 t, 100 g:1 t, 130 g:1 t, 150 g:1 t or any range between the two.

[0053] In some specific embodiments, in step (e), the mass ratio of the second collector to the second flotation rougher concentrate is 100-250 g:1 t, including but not limited to any one of 100 g:1 t, 130 g:1 t, 150 g:1 t, 180 g:1 t, 200 g:1 t, 250 g:1 t, or any range between the two.

[0054] For some specific implementation methods, see Figure 1 As shown, in step (c), the tailings from the first flotation process are returned to the first flotation scavenging system for a second flotation scavenging.

[0055] For some specific implementation methods, see Figure 1 As shown, step (d) further includes the following steps: performing a second flotation scavenging on the second flotation rougher tailings to obtain a second flotation scavenging concentrate, and returning the second flotation scavenging concentrate to the second flotation rougher system for a second flotation roughering process.

[0056] It is understandable that while obtaining the second flotation scavenging concentrate, the second flotation scavenging tailings are also obtained, and the second flotation scavenging tailings can be discarded.

[0057] For some specific implementation methods, see Figure 1 As shown, in step (e), the tailings from the second flotation process are returned to the second flotation roughing system for a second flotation roughing process.

[0058] It is understandable that the method of comprehensive recycling of titanium dust is a continuous process in actual production. Therefore, the tailings from the first flotation, the scavenging concentrate from the second flotation, and the tailings from the second flotation can be transported through pipelines to the upper-level flotation system for re-flotation, and activated carbon and / or titanium concentrate can be collected again to improve the utilization rate of raw materials and avoid waste of resources.

[0059] In some specific embodiments, the titanium concentrate flotation reagents used in the second flotation scavenging include a second frother and a second collector; wherein the second frother includes pine oil and / or 2-octanol; the second collector includes salicylhydroxyxamic acid and / or sodium dithiocarbonate; the mass ratio of the second frother to the second flotation rougher tailings is 80-200 g: 1 t; the mass ratio of the second collector to the second flotation rougher tailings is 120-300 g: 1 t.

[0060] In some specific embodiments, the flotation equipment used in each step of the present invention includes any flotation equipment commonly used in the art, such as flotation machines, flotation columns, etc., but is not limited thereto.

[0061] In some specific embodiments, step (e) further includes a water washing and drying step after the solid-liquid separation.

[0062] In some specific embodiments, the method for comprehensive recycling of reduced titanium dust provided by the present invention has a high carbon recovery rate, wherein the recovery rate of activated carbon is ≥91%, including but not limited to any one of 91%, 91.5%, 92%, 92.5%, 93%, 93.5%, 94%, 95%, 96%, 98% or any range between two of them.

[0063] In some specific embodiments, the methylene blue adsorption value of the activated carbon is ≥258 mg / g, including but not limited to the point value of any one of 258 mg / g, 260 mg / g, 265 mg / g, 270 mg / g, 275 mg / g, 280 mg / g, 290 mg / g, and 300 mg / g, or the range between any two.

[0064] In some specific embodiments, the method for comprehensive recycling of reduced titanium dust provided by the present invention has a high titanium recovery rate, wherein the recovery rate of the titanium concentrate is ≥65%; including but not limited to any one of 65%, 66%, 67%, 68%, 69%, 70% or any range between two of them.

[0065] In some specific embodiments, the method for comprehensive recycling of reduced titanium dust provided by the present invention has a high titanium grade, wherein the titanium concentrate has a grade ≥52%, including but not limited to any one of 52%, 53%, 54%, 55%, 56%, 58%, and 60%, or any range between two of them.

[0066] The grade of titanium concentrate refers to the mass fraction of titanium dioxide in the titanium concentrate.

[0067] The principle of the method for comprehensive recycling of reduced titanium dust provided by this invention is as follows:

[0068] The reduced titanium dust mainly consists of unreacted ilmenite, the reduced titanium obtained from the reaction, activated carbon carbonized at high temperature by coal-based reducing agent, and silicon and aluminum impurities in the ilmenite. Because its particle size is relatively small, it is blown out from the flue and constitutes the reduced titanium dust.

[0069] Because the dust particles from the reduced titanium collection are relatively fine, the flotation method used in this invention is more conducive to the combined recovery of activated carbon and ilmenite.

[0070] Firstly, for the flotation recovery of activated carbon, after the pulp is prepared to a suitable concentration, it is added to the flotation equipment. Due to the significant differences in specific gravity, surface morphology, and other properties between activated carbon and ilmenite and silica-alumina impurities, qualified activated carbon products can be obtained without further fine selection after the first roughing stage. However, in order to improve the overall activated carbon yield, scavenging is required to recover a larger proportion of activated carbon. Compared to roughing, the activated carbon scavenging concentrate obtained by scavenging is more likely to contain more ilmenite and silica-alumina impurities. Therefore, the activated carbon scavenging concentrate needs to undergo a fine selection step to ensure the quality of the activated carbon. The tailings obtained from the activated carbon fine selection can be returned to the next stage of scavenging to ensure the overall recovery rate of ilmenite. Before flotation of ilmenite, water washing is performed after activated carbon flotation. This is mainly because the flotation reagents used in the two flotation steps are different, and the activated carbon flotation reagents may have some impact on ilmenite flotation. Therefore, pressure filtration and water washing can minimize this impact. Since the separation of ilmenite from silica and alumina impurities is difficult, high-grade ilmenite cannot be obtained by roughing alone in the second flotation. A second cleaning process is required after the second flotation roughing to obtain a high-quality ilmenite product. The tailings from the second flotation cleaning can be returned to the upper stage of flotation to improve the overall titanium yield. The tailings from the second flotation roughing have a large gap between the index requirements of the second flotation scavenging tailings and the titanium concentrate. A good titanium concentrate cannot be obtained by the first cleaning process either. Therefore, it can be returned to the upper stage of flotation and re-enter the flotation system. The majority of the components in the second flotation scavenging tailings are silica and alumina impurities, which can be directly discarded.

[0071] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0072] To compare the recovery rates of the various embodiments and comparative examples, the same batch of reduced titanium dust was used in the following embodiments and comparative examples of the present invention. Its chemical composition, by mass percentage, was: C 45.65%, TiO2 18.04%, Fe2O3 14.41%, Al2O3 3.85%, SiO2 12.34%, with the balance being impurities (including elements such as calcium, magnesium, sodium, potassium, and manganese). However, the recyclable reduced titanium dust of the present invention is not limited to this, and the above chemical composition should not be considered as limiting the scope of the present invention.

[0073] Example 1

[0074] The method for comprehensive recycling of reduced titanium dust provided in this embodiment includes the following steps:

[0075] (1) Reduced titanium dust is mixed with water to prepare a slurry with a mass fraction of 25%, and then thoroughly stirred and mixed. Activated carbon flotation reagent is added to the slurry. The activated carbon flotation reagent is pine oil and diesel oil with a mass ratio of 3:2. The mass of activated carbon flotation reagent added per ton of dust is 1400g. The first flotation roughing is carried out to obtain the first flotation roughing concentrate and the first flotation roughing tailings.

[0076] (2) Add activated carbon flotation reagent to the first flotation rougher tailings. The mass of activated carbon flotation reagent added per ton of the first flotation rougher tailings is 150g. Perform the first flotation scavenging to obtain the first flotation scavenging concentrate and the first flotation scavenging tailings.

[0077] (3) Activated carbon flotation reagent is added to the first flotation scavenging concentrate, with a mass of 150g of activated carbon flotation reagent added per ton of the first flotation scavenging concentrate. The first flotation cleaning process is then performed to obtain the first flotation cleaned concentrate and the first flotation cleaned tailings. The first flotation cleaned tailings are returned to the first flotation scavenging system for repeated first flotation scavenging. The first flotation cleaned concentrate and the first flotation roughing concentrate are combined (i.e., mixed), then pressure filtered and dried to obtain activated carbon with a methylene blue adsorption value of 279mg / g and an activated carbon recovery rate of 94.64%.

[0078] (4) After the tailings from the first flotation scavenging are pressure filtered and washed with water, water is added to prepare a slurry with a mass fraction of 40%. Dilute sulfuric acid with a mass fraction of 5% is added to the slurry to adjust the pH of the slurry to 5. Then, pine oil and salicylic acid are added to it. The mass of pine oil added per ton of the first flotation scavenging tailings is 800g, and the mass of salicylic acid added per ton of the first flotation scavenging tailings is 1200g. The second flotation roughing is carried out to obtain the second flotation roughing concentrate and the second flotation roughing tailings.

[0079] (5) Add pine oil and salicylic acid to the second flotation rougher concentrate, wherein the mass of pine oil added per ton of the second flotation rougher concentrate is 150g and the mass of salicylic acid added per ton of the second flotation rougher concentrate is 250g. Perform second flotation cleaning to obtain the second flotation cleaned concentrate and the second flotation cleaned tailings. Filter and dry the second flotation cleaned concentrate to obtain a titanium concentrate with a grade of 55.49% and a recovery rate of 68.55%.

[0080] Pinyl alcohol oil and salicylic acid are added to the roughing tailings of the second flotation. The amount of pinyl alcohol oil added per ton of roughing tailings is 100g, and the amount of salicylic acid added per ton of roughing tailings is 150g. The second flotation is then carried out by scavenging to obtain the second flotation scavenging concentrate and the second flotation scavenging tailings. The second flotation scavenging concentrate is then returned to the second flotation roughing system for a second flotation roughing process.

[0081] The tailings from the second flotation process are returned to the second flotation roughing system for a second flotation roughing process.

[0082] Example 2

[0083] The method for comprehensive recycling of reduced titanium dust provided in this embodiment includes the following steps:

[0084] (1) Reduced titanium dust is mixed with water to prepare a slurry with a mass fraction of 40%, and then thoroughly stirred and mixed. Activated carbon flotation reagent is added to the slurry. The activated carbon flotation reagent is pine oil and diesel oil with a mass ratio of 3:2. The mass of activated carbon flotation reagent added per ton of dust is 1400g. The first flotation roughing is carried out to obtain the first flotation roughing concentrate and the first flotation roughing tailings.

[0085] (2) Add activated carbon flotation reagent to the first flotation rougher tailings. The mass of activated carbon flotation reagent added per ton of the first flotation rougher tailings is 150g. Perform the first flotation scavenging to obtain the first flotation scavenging concentrate and the first flotation scavenging tailings.

[0086] (3) Activated carbon flotation reagent is added to the first flotation scavenging concentrate, with a mass of 150g of activated carbon flotation reagent added per ton of the first flotation scavenging concentrate. The first flotation cleaning process is then performed to obtain the first flotation cleaned concentrate and the first flotation cleaned tailings. The first flotation cleaned tailings are returned to the first flotation scavenging system for repeated first flotation scavenging. The first flotation cleaned concentrate and the first flotation roughing concentrate are combined (i.e., mixed), then pressure filtered and dried to obtain activated carbon with a methylene blue adsorption value of 268.5mg / g and an activated carbon recovery rate of 92.87%.

[0087] (4) After the first flotation scavenging tailings are pressure filtered and washed with water, water is added to prepare a slurry with a mass fraction of 50%. Dilute sulfuric acid with a mass fraction of 5% is added to the slurry to adjust the pH of the slurry to 5. Then, pine oil and salicylic acid are added to it. The mass of pine oil added per ton of the first flotation scavenging tailings is 800g, and the mass of salicylic acid added per ton of the first flotation scavenging tailings is 1200g. The second flotation roughing is carried out to obtain the second flotation roughing concentrate and the second flotation roughing tailings.

[0088] (5) Add pine oil and salicylic acid to the second flotation rougher concentrate, wherein the mass of pine oil added per ton of the second flotation rougher concentrate is 150g and the mass of salicylic acid added per ton of the second flotation rougher concentrate is 250g. Perform second flotation cleaning to obtain the second flotation cleaned concentrate and the second flotation cleaned tailings. Filter and dry the second flotation cleaned concentrate to obtain a titanium concentrate with a grade of 54.63% and a recovery rate of 67.27%.

[0089] Pinyl alcohol oil and salicylic acid are added to the roughing tailings of the second flotation. The amount of pinyl alcohol oil added per ton of roughing tailings is 100g, and the amount of salicylic acid added per ton of roughing tailings is 150g. The second flotation is then carried out by scavenging to obtain the second flotation scavenging concentrate and the second flotation scavenging tailings. The second flotation scavenging concentrate is then returned to the second flotation roughing system for a second flotation roughing process.

[0090] The tailings from the second flotation process are returned to the second flotation roughing system for a second flotation roughing process.

[0091] Example 3

[0092] The method for comprehensive recycling and utilization of reduced titanium dust provided in this embodiment includes the following steps:

[0093] (1) Reduced titanium dust is mixed with water to prepare a slurry with a mass fraction of 25%, and then thoroughly stirred and mixed. Activated carbon flotation reagent is added to the slurry. The activated carbon flotation reagent is pine oil and diesel oil with a mass ratio of 2:3. The mass of activated carbon flotation reagent added per ton of dust is 1400g. The first flotation roughing is carried out to obtain the first flotation roughing concentrate and the first flotation roughing tailings.

[0094] (2) Add activated carbon flotation reagent to the first flotation rougher tailings. The mass of activated carbon flotation reagent added per ton of the first flotation rougher tailings is 150g. Perform the first flotation scavenging to obtain the first flotation scavenging concentrate and the first flotation scavenging tailings.

[0095] (3) Activated carbon flotation reagent is added to the first flotation scavenging concentrate, with a mass of 150g of activated carbon flotation reagent added per ton of the first flotation scavenging concentrate. The first flotation cleaning process is then performed to obtain the first flotation cleaned concentrate and the first flotation cleaned tailings. The first flotation cleaned tailings are returned to the first flotation scavenging system for repeated first flotation scavenging. The first flotation cleaned concentrate and the first flotation roughing concentrate are combined (i.e., mixed), then pressure filtered and dried to obtain activated carbon with a methylene blue adsorption value of 258mg / g and an activated carbon recovery rate of 91.15%.

[0096] (4) After the first flotation scavenging tailings are pressure filtered and washed with water, water is added to prepare a slurry with a mass fraction of 40%. Dilute sulfuric acid with a mass fraction of 5% is added to the slurry to adjust the pH of the slurry to 6. Then, pine oil and salicylic acid are added to it. The mass of pine oil added per ton of the first flotation scavenging tailings is 650g, and the mass of salicylic acid added per ton of the first flotation scavenging tailings is 1400g. The second flotation roughing is carried out to obtain the second flotation roughing concentrate and the second flotation roughing tailings.

[0097] (5) Add pine oil and salicylic acid to the second flotation rougher concentrate, wherein the mass of pine oil added per ton of the second flotation rougher concentrate is 150g and the mass of salicylic acid added per ton of the second flotation rougher concentrate is 250g. Perform second flotation cleaning to obtain the second flotation cleaned concentrate and the second flotation cleaned tailings. Filter and dry the second flotation cleaned concentrate to obtain a titanium concentrate with a grade of 52.39% and a recovery rate of 65.64%.

[0098] Pinyl alcohol oil and salicylic acid are added to the roughing tailings of the second flotation. The amount of pinyl alcohol oil added per ton of roughing tailings is 100g, and the amount of salicylic acid added per ton of roughing tailings is 150g. The second flotation is then carried out by scavenging to obtain the second flotation scavenging concentrate and the second flotation scavenging tailings. The second flotation scavenging concentrate is then returned to the second flotation roughing system for a second flotation roughing process.

[0099] The tailings from the second flotation process are returned to the second flotation roughing system for a second flotation roughing process.

[0100] Example 4

[0101] The method for comprehensive recycling and utilization of reduced titanium dust provided in this embodiment includes the following steps:

[0102] (1) Reduced titanium dust is mixed with water to prepare a slurry with a mass fraction of 25%, and then thoroughly stirred and mixed. Activated carbon flotation reagent is added to the slurry. The activated carbon flotation reagent is pine oil and diesel oil with a mass ratio of 3:2. The mass of activated carbon flotation reagent added per ton of dust is 1400g. The first flotation roughing is carried out to obtain the first flotation roughing concentrate and the first flotation roughing tailings.

[0103] (2) Add activated carbon flotation reagent to the first flotation rougher tailings. The mass of activated carbon flotation reagent added per ton of the first flotation rougher tailings is 80g. Perform the first flotation scavenging to obtain the first flotation scavenging concentrate and the first flotation scavenging tailings.

[0104] (3) Activated carbon flotation reagent is added to the first flotation scavenging concentrate, with a mass of 80g of activated carbon flotation reagent added per ton of the first flotation scavenging concentrate. The first flotation cleaning process is then performed to obtain the first flotation cleaned concentrate and the first flotation cleaned tailings. The first flotation cleaned tailings are returned to the first flotation scavenging system for repeated first flotation scavenging. The first flotation cleaned concentrate and the first flotation roughing concentrate are combined (i.e., mixed), then pressure filtered and dried to obtain activated carbon with a methylene blue adsorption value of 271.5 mg / g and an activated carbon recovery rate of 93.75%.

[0105] (4) After the tailings from the first flotation scavenging are pressure filtered and washed with water, water is added to prepare a slurry with a mass fraction of 40%. Dilute sulfuric acid with a mass fraction of 5% is added to the slurry to adjust the pH of the slurry to 5. Then, pine oil and salicylic acid are added to it. The mass of pine oil added per ton of the first flotation scavenging tailings is 800g, and the mass of salicylic acid added per ton of the first flotation scavenging tailings is 1200g. The second flotation roughing is carried out to obtain the second flotation roughing concentrate and the second flotation roughing tailings.

[0106] (5) Add pine oil and salicylic acid to the second flotation rougher concentrate, wherein the mass of pine oil added per ton of the second flotation rougher concentrate is 120g and the mass of salicylic acid added per ton of the second flotation rougher concentrate is 175g. Perform second flotation cleaning to obtain the second flotation cleaned concentrate and the second flotation cleaned tailings. Filter and dry the second flotation cleaned concentrate to obtain a titanium concentrate with a grade of 54.92% and a recovery rate of 67.58%.

[0107] Pinyl alcohol oil and salicylic acid are added to the roughing tailings of the second flotation. The amount of pinyl alcohol oil added per ton of roughing tailings is 80g, and the amount of salicylic acid added per ton of roughing tailings is 120g. The second flotation is then carried out by scavenging to obtain the second flotation scavenging concentrate and the second flotation scavenging tailings. The second flotation scavenging concentrate is then returned to the second flotation roughing system for a second flotation roughing process.

[0108] The tailings from the second flotation process are returned to the second flotation roughing system for a second flotation roughing process.

[0109] Example 5

[0110] The method for comprehensive recycling of reduced titanium dust provided in this embodiment is basically the same as that in Embodiment 1. The difference is that in steps (1), (2) and (3), pine oil is replaced with an equal mass of octanol, and diesel is replaced with an equal mass of kerosene.

[0111] In step (3) of this embodiment, activated carbon with a methylene blue adsorption value of 265.5 mg / g was obtained, and the recovery rate of activated carbon was 93.18%.

[0112] In step (5) of this embodiment, a titanium concentrate with a grade of 54.81% and a recovery rate of 68.09% is obtained.

[0113] Example 6

[0114] The method for comprehensive recycling of reduced titanium dust provided in this embodiment is basically the same as that in embodiment 1. The difference is that in steps (4) and (5), pine oil is replaced with an equal mass of octanol, and salicylhydroxyxamic acid is replaced with an equal mass of sodium dithiocarbonate.

[0115] In step (3) of this embodiment, activated carbon with a methylene blue adsorption value of 274.5 mg / g was obtained, and the recovery rate of activated carbon was 94.37%.

[0116] In step (5) of this embodiment, a titanium concentrate with a grade of 54.23% and a recovery rate of 66.89% is obtained.

[0117] Example 7

[0118] The method for comprehensive recycling of reduced titanium dust provided in this embodiment is basically the same as that in embodiment 1. The difference is that in step (1), the mass fraction of the slurry is replaced with 55%; and in step (4), the mass fraction of the slurry is replaced with 65%.

[0119] In step (3) of this embodiment, activated carbon with a methylene blue adsorption value of 270.0 mg / g was obtained, and the recovery rate of activated carbon was 93.16%.

[0120] In step (5) of this embodiment, a titanium concentrate with a grade of 52.39% and a recovery rate of 62.48% is obtained.

[0121] Comparative Example 1

[0122] The method for comprehensive recycling of reduced titanium dust provided in this comparative example is basically the same as that in Example 1, except that: the first flotation scavenging in step (2) and the first flotation cleaning in step (3) are not performed. Instead, the first flotation rough concentrate obtained in step (1) is directly filtered and dried to obtain activated carbon with a methylene blue adsorption value of 268.5 mg / g and an activated carbon recovery rate of 68.85%.

[0123] In this comparative example, step (5) yielded a titanium concentrate with a grade of 50.64% and a recovery rate of 43.77%.

[0124] Comparative Example 2

[0125] The method for comprehensive recycling of reduced titanium dust provided in this comparative example is basically the same as that in Example 1, except that: the first flotation cleaning step (3) is not performed, but the first flotation scavenging concentrate obtained in step (2) is combined with the first flotation roughing concentrate obtained in step (1), and then filtered and dried to obtain activated carbon with a methylene blue adsorption value of 241.5 mg / g and a recovery rate of 94.83%; and the second flotation cleaning step (5) is not performed, but the second flotation roughing concentrate obtained in step (4) is directly filtered and dried to obtain a titanium concentrate with a grade of 42.46% and a recovery rate of 55.09%.

[0126] In the above embodiments and comparative examples, the quality of activated carbon was tested using methylene blue adsorbent. The specific method is as follows: a methylene blue solution with a mass concentration of 1.5 g / L was prepared for use. The activated carbon sample was ground until more than 90% could pass through a 0.045 mm test sieve. The sample remaining on the sieve was mixed with the methylene blue adsorbent and dried in an electric thermostatic drying oven at 150°C for 2 hours. The sample was then placed in a desiccator to cool and was ready for use. Weigh 0.1g ± 0.0004g of the sample and place it in a 100mL Erlenmeyer flask. Add 5mL to 15mL of methylene blue solution using a dropper, seal the flask tightly, and shake it on a shaker for 30min. Filter the methylene blue solution adsorbed by the sample into a colorimetric tube and mix well. Using a 10mL cuvette at a wavelength of 665nm, with water as a reference, measure the absorbance of the filtrate. The absorbance of the filtrate should differ from the absorbance reading of the copper sulfate standard solution within ±0.020. If it exceeds this range, adjust the amount of methylene blue solution added and repeat the above operation until the requirements are met. The methylene blue adsorption value E is then expressed in mg / g and is calculated as follows: E = cV / m, where c is the concentration of the methylene blue solution in milligrams per milliliter (mg / mL), V is the volume of methylene blue solution consumed by the sample in mL, and m is the mass of the sample in grams (g).

[0127] In the above embodiments and comparative examples, the method for testing the grade of titanium concentrate is as follows: Weigh 0.2000 g (accuracy 0.0002 g) of the sample into a 30 ml crucible, cover it with 8 g of pre-treated and dried potassium pyrosulfate, and melt it in a muffle furnace heated to 750 °C for 10 min. After the time is up, remove the crucible with crucible tongs and allow it to cool slightly. Place the crucible in a 500 ml beaker, add 100 ml of HCl, and heat it on an electric furnace to separate the melt from the crucible. Wash the crucible out. Continue heating until the melt is completely dissolved in the liquid (preventing splashing throughout the process). While still hot, transfer the solution to a 500ml Erlenmeyer flask. Add 30ml of concentrated hydrochloric acid and 3g of aluminum sheet to the flask. Immediately plug the flask with a liquid-sealed funnel and seal it with saturated sodium bicarbonate solution. Heat appropriately to allow the aluminum sheet to react. Remove the furnace and wait until the aluminum sheet has largely reacted. Then return the flask to the furnace and heat until large bubbles appear. Remove it and cool it to room temperature with cold water. Remove the liquid-sealed funnel and add 5ml of 40% ammonium thiocyanate indicator. Rapidly titrate with 0.05mol / L ferric ammonium sulfate standard solution until a stable pale red endpoint is reached. Therefore, TiO2% = (C × V × 0.0799 / m) × 100, where: C represents the concentration of ferric ammonium sulfate (mol / L); V represents the volume of ferric ammonium sulfate consumed (ml); and m represents the sample weight (g).

[0128] In summary, the method for comprehensive recycling of reduced titanium dust provided by this invention can efficiently recover and enrich titanium concentrate and activated carbon in reduced titanium dust, and has a high recovery rate. The resulting activated carbon has a high adsorption value for methylene blue, and the resulting titanium concentrate has a high grade.

[0129] Although the present invention has been illustrated and described with specific embodiments, it should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, without departing from the spirit and scope of the present invention; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention; therefore, this means that all such substitutions and modifications that fall within the scope of the present invention are included in the appended claims.

Claims

1. A method for the comprehensive recycling and utilization of reduced titanium dust, characterized in that, Includes the following steps: (a) The slurry containing reduced titanium dust is mixed with activated carbon flotation reagent and subjected to the first flotation roughing to obtain the first flotation roughing concentrate and the first flotation roughing tailings; (b) The first flotation rougher tailings are mixed with the activated carbon flotation reagent and subjected to the first flotation scavenging to obtain the first flotation scavenging concentrate and the first flotation scavenging tailings; (c) The first flotation scavenging concentrate is mixed with the activated carbon flotation reagent and subjected to the first flotation cleaning process to obtain the first flotation clean concentrate and the first flotation clean tailings; the first flotation clean concentrate is mixed with the first flotation roughing concentrate and then separated into solid and liquid phases to obtain activated carbon. (d) The first flotation scavenging tailings are mixed with titanium concentrate flotation reagents and subjected to a second flotation roughing to obtain a second flotation roughing concentrate and a second flotation roughing tailings; (e) The second flotation rougher concentrate is mixed with the titanium concentrate flotation reagent and subjected to a second flotation cleaning process to obtain a second flotation clean concentrate and a second flotation clean tailings; the second flotation clean concentrate is then subjected to solid-liquid separation to obtain titanium concentrate; In steps (a), (b), and (c), the activated carbon flotation reagent mainly consists of a first frother and a first collector in a mass ratio of 2-4:1-3. The first foaming agent includes pine oil and / or 2-octanol; The first collector includes diesel oil and / or kerosene; In steps (d) and (e), the titanium concentrate flotation reagent includes a second frother and a second collector; The second foaming agent includes pine oil and / or 2-octanol; The second collector includes salicylic acid and / or sodium dithiocarbonate; In step (a), the mass ratio of the activated carbon flotation reagent to the reduced titanium dust in the slurry containing reduced titanium dust is 600~2000g:1t; In step (b), the mass ratio of the activated carbon flotation reagent to the first flotation rougher tailings is 50~200g:1t; And / or, in step (c), the mass ratio of the activated carbon flotation reagent to the first flotation scavenging concentrate is 50~200g:1t; In step (d), before mixing, the first flotation scavenging tailings are subjected to solid-liquid separation and water washing, and then mixed evenly with water to form a slurry; the slurry is then mixed with the titanium concentrate flotation reagent and subjected to the second flotation roughing; the pH of the slurry is 4~6; In step (d), the mass ratio of the second collector to the first flotation scavenging tailings is 800~1600g:1t; In step (e), the mass ratio of the second collector to the second flotation rougher concentrate is 100~250g:1t; The recovery rate of the activated carbon is ≥91%; The methylene blue adsorption value of the activated carbon is ≥258 mg / g; The recovery rate of the titanium concentrate is ≥65%; And / or, the grade of the titanium concentrate is ≥52%.

2. The method for comprehensive recycling and utilization of reduced titanium dust according to claim 1, characterized in that, In step (a), the mass fraction of reduced titanium dust in the slurry containing reduced titanium dust is 15% to 40%.

3. The method for comprehensive recycling and utilization of reduced titanium dust according to claim 1, characterized in that, In step (d), the mass fraction of the first flotation scavenging tailings in the slurry is 30% to 50%.

4. The method for comprehensive recycling and utilization of reduced titanium dust according to claim 1, characterized in that, It includes at least one of the following features (1) to (2): (1) In step (d), the mass ratio of the second frother to the first flotation scavenging tailings is 600~1000g:1t; (2) In step (e), the mass ratio of the second frother to the second flotation rougher concentrate is 50~150g:1t.

5. The method for comprehensive recycling and utilization of reduced titanium dust according to claim 1, characterized in that, It includes at least one of the following features (1) to (3): (1) In step (c), the tailings from the first flotation process are returned to the first flotation scavenging system for a second flotation scavenging process; (2) Step (d) also includes the following steps: the second flotation rougher tailings are subjected to a second flotation scavenging to obtain a second flotation scavenging concentrate, and the second flotation scavenging concentrate is returned to the second flotation rougher system for a second flotation roughering. (3) In step (e), the tailings from the second flotation process are returned to the second flotation roughing system for a second flotation roughing process.

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