A method for comprehensive utilization of fixed carbon and titanium resources in molten salt chloride slag

Abstract

The present invention discloses a method for comprehensively utilizing fixed carbon and titanium resources in molten salt chloride slag, wherein the tailings after water treatment of the molten salt chloride slag are subjected to slag screening-coarse grain grinding and returned to the slag screening-flotation for pre-decarbonization-decarbonized coarse concentrate is regrinded and flotation is performed to select fixed carbon concentrate-flotation underflow classification-gravity selection process to recover fixed carbon and titanium resources, so that fixed carbon can be used as fuel, and the titanium concentrate product is used alone, added to the titanium concentrate electric furnace smelting operation or as a sulfuric acid process titanium dioxide raw material, thereby realizing high-value comprehensive utilization of solid waste; overcoming the defects of molten salt chloride slag currently being treated by stacking or landfilling, which will occupy a large amount of land resources and has environmental risks. The method has the advantages of relatively low process cost and easy industrialization, can be widely used in the field of comprehensive utilization of vanadium titanium magnetite high calcium magnesium titanium concentrate molten salt chloride slag, and has great practical value and promotion value.

Description

Technical Field

[0001] The invention belongs to the technical field of comprehensive utilization of vanadium-titanium magnetite solid waste, and specifically relates to a method for comprehensively utilizing fixed carbon and titanium resources in molten salt chloride slag. Background Art

[0002] Petroleum coke is a product produced by separating the light and heavy oils through distillation of crude oil, followed by thermal cracking of the heavy oil. It appears as irregularly shaped, black lumps or granules of varying sizes. Compared to metallurgical coke, it has lower density, lower ash content, and lower sulfur content. Its carbon grid flakes are more uniformly stacked and the distances between flakes are closer. Petroleum coke is primarily used in graphite production, smelting, and the chemical industry. It is added as fuel in the chlorination process of high-titanium slag molten salt.

[0003] Titanium is a valuable and strategically important metal, boasting a range of unparalleled properties, including high specific strength, lightweight, corrosion resistance, shape memory, excellent ductility and biocompatibility, superconductivity, and strong surface decorative properties. It is widely used in a wide range of fields, including aerospace, petrochemicals, construction, power generation, healthcare, and sporting goods. Titanium is known as the "third metal" after iron and aluminum. TiO2 is the best white inorganic pigment and is widely used in coatings, plastics, chemical fibers, rubber, papermaking, printing inks, and cosmetics. TiCl4 is the primary intermediate raw material for the production of titanium metal and titanium dioxide, playing a central role in the titanium industry chain. The main industrially valuable titanium-containing minerals in nature are ilmenite and rutile. Industrially, these titanium resources, such as ilmenite and rutile, are primarily used to produce titanium metal and titanium dioxide products. Titanium concentrates are smelted in electric furnaces to produce high-titanium slag, which is then chlorinated to produce TiCl4. The resulting slag is then subjected to magnesium-thermal reduction and distillation to produce titanium sponge, or directly subjected to vapor-phase oxidation and post-processing to produce titanium dioxide chloride. The industrial production process of titanium dioxide and titanium metal is as follows: Figure 2 shown.

[0004] The molten salt chlorination method is mainly used to produce TiCl4, which is mainly used to process titanium raw materials with high calcium and magnesium impurity content. It is characterized by suspending titanium slag and petroleum coke in a molten salt medium (mainly composed of NaCl, KCl, FeCl2, MgCl2, and CaCl2) and reacting with Cl2 to produce TiCl4. The specific process flow is shown in Figure 3 This process was introduced to China from Ukraine in the 1990s. It successfully achieved industrialized production of crude TiCl4 by carbon thermal chlorination of low-grade, high-calcium-magnesium titanium slag with a TiO2 content of 78% to 85% in a NaCl-based molten salt system. The chlorination rate of titanium oxide is >92%, solving the practical production problems of large-scale chlorination equipment and capacity expansion.

[0005] Titanium slag produced from ilmenite concentrate from vanadium-titanium magnetite contains multiple metal oxides, a low TiO2 content (72-75%), high calcium and magnesium impurities (CaO + MgO: 7-8.5%), and a relatively high FeO content (7.5-10%). Average SiO2, Al2O3, and MnO contents are 4.69%, 1.81%, and 1.08%, respectively. The chlorination process produces a large amount of slag and dust collection. Statistics show that for every ton of TiCl4 produced, approximately 1.6 tons of molten salt chloride slag are generated. This molten salt chloride slag contains a large amount of insoluble matter, such as artificial silicates and titanium-containing artificial minerals, as well as a large amount of unburned organic matter (petroleum coke or calcined coke), resulting in a significant waste of resources. Currently, molten salt chloride slag is primarily disposed of by stockpiling and landfilling. This occupies a significant amount of land resources, poses certain environmental risks, and carries high storage costs, limiting the large-scale application of molten salt chlorination methods for high-calcium-magnesium ilmenite concentrate. Summary of the Invention

[0006] To address the comprehensive utilization of molten salt chloride slag from high-calcium-magnesium titanium concentrate from vanadium-titanium magnetite, a method for comprehensively utilizing the fixed carbon and titanium resources in the molten salt chloride slag from high-calcium-magnesium titanium concentrate from vanadium-titanium magnetite has been developed. This method significantly enriches titanium-containing minerals and organic matter in the molten salt chloride slag from high-calcium-magnesium titanium concentrate from vanadium-titanium magnetite, laying the foundation for further economic utilization. This method has the advantages of relatively low utilization cost and easy industrialization. It can be widely applied to the comprehensive utilization of molten salt chloride slag from high-calcium-magnesium titanium concentrate from vanadium-titanium magnetite, and has great practical and promotional value.

[0007] A method for comprehensively utilizing fixed carbon and titanium resources in molten salt chloride slag comprises the following steps:

[0008] S1: Feed the material (molten salt chloride slag) and water into the mixing tank at a uniform speed for the first slurry mixing, and control the material concentration to be 60-75%.

[0009] S2 controls the stirring speed to 2000~4000rad / min for high-speed stirring and scrubbing;

[0010] S3: Add water to the overflow of stirring and scrubbing, control the material concentration to 20-30%, and then sieve to separate the slag, the sieve hole diameter is 0.5-1.5mm;

[0011] The product on the S4 screen undergoes the first grinding, and the first grinding product returns to the slag screen;

[0012] The product under the S5 slag screen is added with light diesel oil (flow rate of 0.7-1.0 mL / min) and 2# oil (flow rate of 0.25-0.40 mL / min) for the second stirring and slurry preparation;

[0013] S6: The material slurry after stirring and slurrying is subjected to the first flotation;

[0014] S7 The first flotation foam is transported to the ball mill for the second grinding;

[0015] The second grinding product of S8 undergoes the first screening and classification, with a classification particle size of 0.074mm to 0.25mm;

[0016] The product on the first screening and grading in S9 is returned to the second grinding, and the product under the screen is added with light diesel oil (flow rate of 0.15-0.30 mL / min) and 2# oil (flow rate of 0.075-0.125 mL / min) for the third stirring and slurry preparation;

[0017] S10 The material slurry after the third stirring and slurrying is subjected to the second flotation, the second flotation foam is used as the organic concentrate, and the second flotation underflow is merged into the first flotation underflow;

[0018] S11 The underflow of the first and second flotation is fed into the second screening and classification, with a classification particle size of 0.15mm, and the product on the screen is used as titanium concentrate 1;

[0019] The products under the second screening and grading in S12 are fed to the third screening and grading, with a grading particle size of 0.074mm. The products on the third screening and grading are fed to the first shaking table for re-selection;

[0020] The first round of S13 shaking table gravity separation has a slope of 3° to 5°, a stroke of 11 to 14 mm, a flushing frequency of 350 to 370 times / min, a feed concentration of 20% to 25%, and a horizontal flushing water volume of 8 to 10 L / min. The heavy minerals are used as titanium concentrate 2, and the light minerals are concentrated for the first time.

[0021] The concentration of the first concentrated underflow of S14 is controlled at 20% to 25%. The first concentrated underflow is subjected to the second shaking table gravity separation. The second shaking table gravity separation has a slope of 2° to 4°, a stroke of 11 to 14 mm, a flushing frequency of 350 to 370 times / min, an ore feed concentration of 20% to 25%, and a horizontal flushing water of 6 to 8 L / min. The heavy minerals are used as titanium concentrate 3, and the light minerals are used as tailings 1;

[0022] The product under the third classification of S15 is fed to the fourth screening and classification, with a particle size of 0.038 mm. The product on the fourth screening and classification is fed to the third shaking table gravity separation, with a slope of 2° to 4°, a stroke of 5 to 7 mm, a flushing frequency of 480 to 520 times / min, an ore concentration of 15% to 20%, and a horizontal flushing water flow of 6 to 8 L / min. The heavy minerals are used as titanium concentrate 4, and the light minerals are fed to the second concentration;

[0023] The concentration of the second concentrated underflow of S16 is controlled at 15% to 20%, and the fourth shaking table gravity separation is carried out with a slope of 2° to 4°, a stroke of 5 to 7 mm, a flushing frequency of 480 to 520 times / min, and a horizontal flushing water of 6 to 8 L / min. The heavy minerals are used as titanium concentrate 5, and the light minerals are used as tailings 2;

[0024] The undersize product of the fourth screening and grading in S17 is used as tailings 3;

[0025] S18 titanium concentrate 1, titanium concentrate 2, titanium concentrate 3, titanium concentrate 4 and titanium concentrate 5 are regarded as total titanium concentrate, and tailings 1, tailings 2 and tailings 3 are regarded as total tailings.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The method utilizes a slag separation process, followed by flotation pre-decarbonization, regrinding and flotation of the decarbonized coarse concentrate to select a fixed carbon concentrate, followed by flotation underflow classification, and then gravity separation to recover fixed carbon and titanium resources. This process significantly enriches fixed carbon and TiO2, laying the foundation for further economic utilization of the molten salt chloride slag from vanadium-titanium magnetite ilmenite concentrate. This method enables the fixed carbon to be used as fuel, and the titanium concentrate product to be used independently, added to titanium concentrate electric furnace smelting operations, or used as a raw material for sulfuric acid-processed titanium dioxide, achieving high-value comprehensive utilization of solid waste. It has the advantages of relatively low process costs and easy industrialization, and can be widely applied in the comprehensive utilization of vanadium-titanium magnetite high-calcium-magnesium titanium concentrate molten salt chloride slag, possessing great practical and promotional value. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a pilot process flow chart for recovering fixed carbon and titanium resources from vanadium-titanium magnetite ilmenite concentrate molten salt chloride slag in an embodiment;

[0029] Figure 2 This is a process flow chart for the industrial production of titanium dioxide and titanium metal;

[0030] Figure 3 This is the process flow chart of titanium slag molten salt chlorination process. DETAILED DESCRIPTION

[0031] The present invention is further described below with reference to specific examples, but is not intended to limit the present invention in any way. To avoid redundancy, the raw materials in the following examples are all commercially available unless otherwise specified; and the methods used are all conventional methods unless otherwise specified.

[0032] Example

[0033] The scale of the embodiment is a laboratory-scale continuous pilot test with a raw ore processing capacity of 100 kg / h. The molten salt chloride tailings (raw ore) sample of vanadium-titanium magnetite ilmenite concentrate contains: fixed C14.30%, Fe2O3 7%, SiO231.03%, CaO5.45%, MgO 4.28%, Al2O3 12.88%, TiO2 20.35%, Mn 1.10%, Cl 0.23%, Na2O 0.62%, -0.074mm accounts for 60.09% of the sample. The sample belongs to the molten salt chloride slag obtained by smelting and chlorinating the high titanium slag after smelting the vanadium titanium magnetite ilmenite concentrate in an electric furnace. The insoluble matter after the molten salt chloride slag is treated with water has fine particle size, heavy mud, and serious adhesion between the powder particles and organic matter; artificial pyroxene accounts for 49.93% of the sample, artificial rutile accounts for 20.70%, organic matter accounts for 15.00%, artificial iron-containing rutile accounts for 4.84%, aluminum titanate accounts for 4.90%, and the amount of other minerals is very small; under the electron microscope, the mineral particle size is uneven, showing a microcrystalline-honeycomb-amorphous-structure, the minerals are embedded in a fine particle size, and encapsulation and cementation are common.

[0034] A method for comprehensively utilizing fixed carbon and titanium resources in molten salt chloride slag, wherein a pilot process of an embodiment of the method comprises the following steps:

[0035] S1: feed the material (vanadium-titanium magnetite, ilmenite concentrate, molten salt, chlorinated tailings) and water into the mixing tank 1 at a uniform speed for the first slurry mixing, and control the material concentration to 70%;

[0036] S2 controls the stirring speed to 3000rad / min for high-speed stirring and scrubbing; the stirred slurry flows into the KM-800-4s rotary vibrating screen 1 for slag separation;

[0037] S3: After stirring and scrubbing the overflow, add water to control the material concentration to 30% and then sieve to separate the slag. The sieve hole diameter is 1.0mm.

[0038] The product on the S4 screen is fed into the XMBL-Φ420×600 continuous ball-and-rod dual-purpose grinding mill for the first grinding, and the first grinding product is returned to the slag screen;

[0039] The product under the S5 slag screen is transported to the mixing barrel 2 (model XTD-15L, with circulation hole) by the XBSL1 / 2 vertical sand pump 1. 400g / t of light diesel oil (flow rate of 0.833mL / min) and 150g / t of 2# oil (flow rate of 0.313mL / min) are added to the mixing barrel 2 for the second stirring and slurry preparation.

[0040] The slurry after slurry mixing in S6 mixing tank 2 flows into the ZGSYF-120 flotation column for the first flotation (roughing);

[0041] The thickness of the first flotation foam layer in S7 is 60-80 mm, the aeration rate is 2.5-3.0 L / min, and the flotation foam flows into the XMB-Φ200×240 continuous ball mill for the second grinding;

[0042] The second grinding product of S8 flows into KM-800-4s rotary vibrating screen 2 for the first screening and classification, with a screen hole diameter of 0.10mm;

[0043] The oversize product of the first screening and grading in S9 is returned to the XMB-Φ200×240 continuous ball mill for the second grinding, and the undersize product is transported to the ZGSYF-80 flotation column by the XBSL1 / 4 vertical sand pump 2 for the second flotation. 100g / t of light diesel oil (flow rate of 0.208mL / min) and 50g / t of 2# oil (flow rate of 0.104mL / min) are added to the undersize product of the XBSL1 / 4 vertical sand pump 2 for the third stirring and slurry preparation.

[0044] S10 The material slurry after the third stirring and slurrying is subjected to the second flotation. The thickness of the second flotation foam layer is 80-100 mm, the aeration volume is 2.5-3.0 L / min, the second flotation foam is used as the organic concentrate, and the second flotation underflow is merged into the first flotation underflow;

[0045] The bottom flow of the first and second flotation in S11 is fed into the KM-800-4s rotary vibrating screen 2 through the XBSL1 / 2 vertical sand pump 3 for the second screening and classification. The classification particle size is 0.15mm, and the product on the screen is used as the titanium concentrate 1;

[0046] The undersize product of the second screening and grading in S12 is fed to the KM-800-4s rotary vibrating screen (with ultrasonic wave) by the XBSL1 / 2 vertical sand pump 4 for the third screening and grading. The grading particle size is 0.074mm and the ultrasonic frequency is 32KHz. The oversize product of the third screening and grading is pumped to the first shaking table for gravity selection by the XBSL1 / 4 vertical sand pump 5; the undersize product is pumped to the fourth grading by the XBSL1 / 2 vertical sand pump 6;

[0047] The first shaking table gravity separation equipment of S13 is a 2100×1150 fine sand shaking table with a slope of 4°, a stroke of 13mm, a flushing frequency of 360 times / min, a feed concentration of 23%, and a horizontal flushing water of 9L / min. The heavy minerals are used as titanium concentrate 2, and the light minerals are pumped into the first concentration through the XBSL1 / 2 vertical sand pump 7;

[0048] The concentration of the first concentrated bottom flow of S14 is controlled at 23%. The first concentrated bottom flow is pumped to the second shaking table gravity separation through the XBSL1 / 4 vertical sand pump 8. The second shaking table gravity separation equipment is a 2100×1150 fine sand shaking table with a slope of 3°, a stroke of 13mm, a flushing frequency of 360 times / min, an ore feed concentration of 23%, and a horizontal flushing water of 7L / min. The heavy minerals are used as titanium concentrate 3 and the light minerals are used as tailings 1;

[0049] The product under the third classification in S15 is fed to the fourth screening and classification. The fourth classification equipment is KM-800-4s rotary vibrating screen (with ultrasonic wave), the fourth classification particle size is 0.038mm, the ultrasonic frequency is 26KHz, and the product on the fourth screening and classification screen is pumped to the third shaking table gravity separation by XBSL1 / 4 vertical sand pump 9; the third shaking table gravity separation equipment is a 2100×1150 ore mud shaking table with a slope of 2°, a stroke of 6mm, a stroke of 500 times / min, an ore concentration of 17%, and a horizontal flushing water of 6L / min. The heavy minerals are used as titanium concentrate 4, and the light minerals are pumped to the second concentration by XBSL1 / 2 vertical sand pump 10;

[0050] The overflow from the second thickening of S16 is used as circulating water, and the concentration of the thickened bottom flow is controlled at 15%. It is pumped by the XBSL1 / 4 vertical sand pump 11 for the fourth shaking table gravity separation. The fourth shaking table gravity separation equipment is a 2100×1150 ore mud shaking table with a slope of 2°, a stroke of 5mm, a stroke of 520 times / min, an ore feed concentration of 15%, and a horizontal flushing water of 6L / min. The heavy minerals are used as titanium concentrate 5, and the light minerals are used as tailings 2;

[0051] The undersize product of the fourth screening and grading in S17 is used as tailings 3;

[0052] S18 titanium concentrate 1, titanium concentrate 2, titanium concentrate 3, titanium concentrate 4 and titanium concentrate 5 are regarded as total titanium concentrate, and tailings 1, tailings 2 and tailings 3 are regarded as total tailings.

[0053] The results show that the tailings of vanadium titano-magnetite ilmenite concentrate molten salt chloride slag water treatment in the example adopt the above equipment and process flow, Figure 1 Using the selected separation conditions and process parameters, a titanium concentrate with a yield of 23.11%, a TiO2 grade of 67.03%, and a TiO2 recovery of 76.12% was obtained, as well as an organic concentrate with a yield of 13.26%, a fixed carbon grade of 89.62%, and a fixed carbon recovery of 83.10%. The pilot results are shown in Table 1, the main chemical composition analysis results of the titanium concentrate are shown in Table 2, and the main chemical composition analysis results of the organic concentrate are shown in Table 3.

[0054] Table 1 Pilot results of recovering fixed carbon and titanium resources from molten salt chloride slag of vanadium-titanium magnetite titanium concentrate

[0055]

[0056] Table 2 Analysis results of main chemical components of titanium concentrate / %

[0057]

[0058] Table 3 Analysis results of main chemical components of organic carbon concentrate / %

[0059]

[0060] Anyone skilled in the art will be able to utilize the above-disclosed technical content to make many possible changes and modifications to the technical solution of the present invention, or to modify it into equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention that do not depart from the content of the technical solution of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for comprehensively utilizing fixed carbon and titanium resources in molten salt chloride slag, characterized in that: The method comprises the following steps: S1 feeds the material and water into the mixing tank at a uniform speed for the first slurry mixing, controlling the material concentration to 60-75%; S2 controls the stirring speed to 2000~4000rad / min for high-speed stirring and scrubbing; S3 stirs and scrubs the overflow in S2, adds water to control the material concentration to 20-30%, and then sieves the slag, with a sieve hole diameter of 0.5-1.5mm; The product on the S4 screen undergoes the first grinding, and the first grinding product returns to the S3 slag screen; The product under the S5 slag screen is added with light diesel oil and 2# oil for the second stirring and slurry preparation; S6: The material slurry after stirring and slurrying is subjected to the first flotation; S7 The first flotation foam is transported to the ball mill for the second grinding; The second grinding product of S8 undergoes the first screening and classification, with a classification particle size of 0.074mm to 0.25mm; The products on the first screening and grading in S9 are returned to the second grinding, and the products under the screen are added with light diesel oil and No. 2 oil for the third stirring and slurry preparation; S10 The material slurry after the third stirring and slurrying is subjected to the second flotation, the second flotation foam is used as the organic concentrate, and the second flotation underflow is merged into the first flotation underflow; S11 The underflow of the first and second flotation is fed into the second screening and classification, with a classification particle size of 0.15mm, and the product on the screen is used as titanium concentrate 1; The products under the second screening and grading in S12 are fed to the third screening and grading, with a grading particle size of 0.074mm. The products on the third screening and grading are fed to the first shaking table for re-selection; The first round of S13 shaking table gravity separation has a slope of 3° to 5°, a stroke of 11 to 14 mm, a flushing frequency of 350 to 370 times / min, a feed concentration of 20 to 25%, and a horizontal flushing water volume of 8 to 10 L / min. The heavy minerals are used as titanium concentrate 2, and the light minerals are concentrated for the first time. The concentration of the first concentrated underflow of S14 is controlled at 20-25%. The first concentrated underflow is subjected to the second shaking table gravity separation. The second shaking table gravity separation has a slope of 2°-4°, a stroke of 11-14 mm, a flushing frequency of 350-370 times / min, an ore feed concentration of 20-25%, and a horizontal flushing water of 6-8 L / min. The heavy minerals are used as titanium concentrate 3, and the light minerals are used as tailings 1; The product under the third classification of S15 is fed to the fourth screening and classification, with a particle size of 0.038 mm. The product on the fourth screening and classification is fed to the third shaking table gravity separation, with a slope of 2° to 4°, a stroke of 5 to 7 mm, a flushing frequency of 480 to 520 times / min, an ore concentration of 15% to 20%, and a horizontal flushing water flow of 6 to 8 L / min. The heavy minerals are used as titanium concentrate 4, and the light minerals are fed to the second concentration; The concentration of the second concentrated underflow of S16 is controlled at 15-20%, and the fourth shaking table gravity separation is carried out with a slope of 2°-4°, a stroke of 5-7mm, a flushing frequency of 480-520 times / min, and a horizontal flushing water of 6-8L / min. The heavy minerals are used as titanium concentrate 5, and the light minerals are used as tailings 2; The undersize product of the fourth screening and grading in S17 is used as tailings 3; S18 titanium concentrate 1, titanium concentrate 2, titanium concentrate 3, titanium concentrate 4 and titanium concentrate 5 are regarded as total titanium concentrate, and tailings 1, tailings 2 and tailings 3 are regarded as total tailings.

2. The method according to claim 1, characterized in that The flow rate of the light diesel oil in step S5 is 0.7-1.0 mL / min, and the flow rate of the 2# oil is 0.25-0.40 mL / min.

3. The method according to claim 1, characterized in that The flow rate of the light diesel oil in step S9 is 0.15-0.30 mL / min, and the flow rate of the 2# oil is 0.075-0.125 mL / min.

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