A method for full-element resource utilization of chlorination process titanium dioxide waste residue

Abstract

The application provides a full-element resource utilization method of chlorination method titanium dioxide waste residue, and belongs to the technical field of resources and environment. The application recycles high-titanium residue and calcined coke reuse raw materials by adopting hydrochloric acid dissolution and reduction technology, recycles vanadium, scandium, niobium, zirconium, chromium and other precious metal elements in the waste residue by adopting a multi-stage extraction process, realizes the production of battery materials from iron and manganese elements in the waste residue by adopting extraction and conversion process, and produces aluminum water purifying agent products through oxidation polymerization of other elements; green low-carbon process is adopted in the whole process, full-element resource utilization is realized; meanwhile, the application also designs an optimized comprehensive utilization process, ensures the rationality of the utilization process, reduces the production cost, and improves the comprehensive benefits.

Description

Technical Field

[0001] This invention relates to the field of resource and environmental technology, and in particular to a method for the full-element resource utilization of titanium dioxide waste residue from the chloride process. Background Technology

[0002] The production of titanium dioxide produced through the chloride process has been increasing year by year, showing a rapid growth trend in China. The treatment of slag and dust from the chloride process is a key and challenging aspect of environmental governance in titanium dioxide production. Because the titanium dioxide used in the chloride process has a high grade and low impurity content, the amount of waste residue is less than that of the sulfate process; however, the treatment of chloride slag is more difficult.

[0003] In the process of producing titanium tetrachloride via fluidized bed chlorination, 50-150 kg of dust slag is generated for every ton of crude titanium tetrachloride produced (depending on the raw materials). This dust slag mainly contains unreacted titanium-rich slag, calcined coke, ferric chloride and ferrous chloride produced by the chlorination reaction, and small amounts of metallic chlorides such as aluminum chloride and manganese chloride, as well as various precious metals. The main metal element content of the titanium dioxide waste residue from a certain enterprise's chlorination process is shown in Table 1.

[0004] Table 1. Main metal element content (%) of titanium dioxide waste residue from the chloride process of a certain enterprise

[0005] Na Al K Ca Sc Ti V Cr Fe 0.48 2.55 0.07 0.42 0.02 4.25 0.58 0.53 15.62 Mn Co Ni Cu Ga Zr Nb Pt - 3.81 0.001 0.008 0.007 0.003 0.52 0.32 0.00006 -

[0006] Currently, the commonly used method for treating waste residue from the fluidized bed chlorination process is dissolution and neutralization. Specifically, the dust-collecting slag is dissolved in acidic water, filtered once, and the solid residue mainly consists of unreacted high-titanium slag and petroleum coke, which can be recycled. The filtrate is neutralized with lime milk, causing metal chlorides to precipitate as hydroxides, and filtered a second time. The solid residue is mainly composed of ferric hydroxide, which is considered general industrial waste and is sent to a landfill. The filtrate is then concentrated and evaporated to produce solid calcium chloride. While this technology is mature, it has two main problems: firstly, it requires a solid waste landfill, occupying a large amount of land; secondly, the most valuable resources in the waste residue are not fully utilized. Summary of the Invention

[0007] The purpose of this invention is to provide a method for the full-element resource utilization of titanium dioxide waste residue from the chloride process, which does not generate new waste residue and wastewater, and can achieve full-element resource utilization, thus having extremely high economic value and environmental benefits.

[0008] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0009] This invention provides a method for the complete resource utilization of titanium dioxide waste residue from the chloride process, comprising the following steps:

[0010] The waste residue from the chloride process titanium dioxide was mixed with water and hydrochloric acid for acid leaching. A reducing agent was added to the resulting acid-leached material to carry out a reduction reaction. The first solid-liquid separation was performed to obtain solid 1 and solution 1. The solid 1 includes titanium dioxide and calcined coke.

[0011] The solution 1 is cooled and crystallized, followed by a second solid-liquid separation to obtain solid 2 and solution 2. The main component of solid 2 is ferrous chloride.

[0012] Scandium in solution 2 is first extracted using extractant 1, and after separation, organic phase 1 and raffinate 1 are obtained. Organic phase 1 is then back-extracted using a first sodium hydroxide solution to obtain scandium oxide.

[0013] Zirconium and chromium in the raffinate 1 are extracted a second time using extractant 2. After separation, organic phase 2 and raffinate 2 are obtained. The organic phase 2 is then back-extracted with sulfuric acid to obtain zirconium oxide and chromium oxide.

[0014] Niobium in the raffinate 2 is extracted for the third time using extractant 3. After separation, organic phase 3 and raffinate 3 are obtained. The organic phase 3 is then back-extracted with oxalic acid to obtain metallic niobium oxide.

[0015] The iron in the raffinate 3 is extracted for the fourth time using extractant 4. After separation, organic phase 4 and raffinate 4 are obtained. The organic phase 4 is then back-extracted for the fourth time using a second sodium hydroxide solution or phosphoric acid solution to obtain iron compounds.

[0016] Vanadium and manganese in the raffinate 4 are extracted for the fifth time using extractant 5. After separation, organic phase 5 and raffinate 5 are obtained. The organic phase 5 is then back-extracted for the fifth time using a second sulfuric acid solution to obtain manganese sulfate product and back-extracted organic phase 5.

[0017] The organic phase 5 after back-extraction was subjected to a sixth back-extraction using sodium carbonate solution to obtain sodium metavanadate.

[0018] The raffinate 5 is mixed with activated carbon to adsorb and remove organic matter. Then the activated carbon is removed, an oxidant is added for oxidation, and the pH value is adjusted to 2-7 to obtain polyaluminum chloride.

[0019] Preferably, the cooling crystallization temperature is below 20°C.

[0020] Preferably, the extractant 1 is composed of P2O4, TBP and solvent oil; the volume content of P2O4 in the extractant 1 is 5-25%, and the volume content of TBP is 3-30%; the volume ratio of the solution 2 to the extractant 1 is 1:1.3.

[0021] Preferably, the concentration of the first sodium hydroxide solution is 1-5 mol / L; the volume ratio of the first sodium hydroxide solution to organic phase 1 is 1:1.

[0022] Preferably, the extractant 2 is composed of P507 and solvent oil; the volume content of P507 in the extractant 2 is 3-25%; and the volume ratio of the raffinate 1 to the extractant 2 is 1:1.6.

[0023] Preferably, the concentration of the first sulfuric acid is 2 to 10 mol / L; the volume ratio of the first sulfuric acid to organic phase 2 is 1:1.7.

[0024] Preferably, the extractant 3 is composed of N235 and solvent oil, and the volume content of N235 in the extractant 3 is preferably 15-20%; the volume ratio of the raffinate 2 to the extractant 3 is preferably 1:1.1.

[0025] Preferably, the concentration of the oxalic acid solution is 2 mol / L; the volume ratio of the oxalic acid solution to the organic phase 3 is 1:4.

[0026] Preferably, the extractant 4 is composed of TBP and solvent oil; the volume content of TBP in the extractant 4 is 3-20%; and the volume ratio of the raffinate 3 to the extractant 4 is 1:1.4.

[0027] Preferably, the extractant 5 is composed of N1923 and solvent oil; the volume content of N1923 in the extractant 5 is 3-15%; and the volume ratio of the raffinate 4 to the extractant 5 is 1:(0.9-1).

[0028] This invention utilizes hydrochloric acid dissolution and reduction technology to recover high-titanium slag and calcined coke for reuse as raw materials. A multi-stage extraction process is employed to recover precious metals such as vanadium, scandium, niobium, zirconium, and chromium from the waste residue. An extraction and conversion process is used to produce battery materials from iron and manganese in the waste residue (specifically, the iron obtained from back-extraction is extracted and refined with phosphoric acid to obtain battery-grade iron phosphate, and the manganese sulfate obtained from back-extraction reacts with ammonium bicarbonate to obtain battery-grade manganese carbonate). Other elements are produced through oxidative polymerization to create aluminum-based water purification agents (polyaluminum chloride). The entire process employs green and low-carbon technology, achieving comprehensive resource utilization. Furthermore, this invention designs an optimized comprehensive utilization process, ensuring rational utilization, reducing production costs, and improving overall efficiency.

[0029] The overall benefits of this invention far exceed those of existing processing technologies.

[0030] This invention produces no wastewater and zero waste residue, resulting in significant energy conservation and emission reduction effects. Attached Figure Description

[0031] Figure 1 A simplified diagram of the process for the comprehensive recovery of scandium, zirconium, and niobium from the hydrochloric acid leaching solution of titanium dioxide waste from the chloride process;

[0032] Figure 2 A simplified diagram of the process for the comprehensive recovery of iron, manganese, and vanadium from the hydrochloric acid leaching solution of titanium dioxide waste residue from the chloride process. Detailed Implementation

[0033] This invention provides a method for the complete resource utilization of titanium dioxide waste residue from the chloride process, comprising the following steps:

[0034] The waste residue from the chloride process titanium dioxide was mixed with water and hydrochloric acid for acid leaching. A reducing agent was added to the resulting acid-leached material to carry out a reduction reaction. The first solid-liquid separation was performed to obtain solid 1 and solution 1. The solid 1 includes titanium dioxide and calcined coke.

[0035] The solution 1 is cooled and crystallized, followed by a second solid-liquid separation to obtain solid 2 and solution 2. The main component of solid 2 is ferrous chloride.

[0036] Scandium in solution 2 is first extracted using extractant 1, and after separation, organic phase 1 and raffinate 1 are obtained. Organic phase 1 is then back-extracted using a first sodium hydroxide solution to obtain scandium oxide.

[0037] Zirconium and chromium in the raffinate 1 are extracted a second time using extractant 2. After separation, organic phase 2 and raffinate 2 are obtained. The organic phase 2 is then back-extracted with sulfuric acid to obtain zirconium oxide and chromium oxide.

[0038] Niobium in the raffinate 2 is extracted for the third time using extractant 3. After separation, organic phase 3 and raffinate 3 are obtained. The organic phase 3 is then back-extracted with oxalic acid to obtain metallic niobium oxide.

[0039] The iron in the raffinate 3 is extracted for the fourth time using extractant 4. After separation, organic phase 4 and raffinate 4 are obtained. The organic phase 4 is then back-extracted for the fourth time using a second sodium hydroxide solution or phosphoric acid solution to obtain iron compounds.

[0040] Vanadium and manganese in the raffinate 4 are extracted for the fifth time using extractant 5. After separation, organic phase 5 and raffinate 5 are obtained. The organic phase 5 is then back-extracted for the fifth time using a second sulfuric acid solution to obtain manganese sulfate product and back-extracted organic phase 5.

[0041] The organic phase 5 after back-extraction was subjected to a sixth back-extraction using sodium carbonate solution to obtain sodium metavanadate.

[0042] The raffinate 5 is mixed with activated carbon to adsorb and remove organic matter. Then the activated carbon is removed, an oxidant is added for oxidation, and the pH value is adjusted to 2-7 to obtain polyaluminum chloride.

[0043] Unless otherwise specified, all raw materials used in this invention are commercially available products well known in the art.

[0044] In this invention, titanium dioxide waste residue from the chloride process is mixed with water and hydrochloric acid for acid leaching. A reducing agent is added to the resulting acid-leached material to carry out a reduction reaction. The first solid-liquid separation is performed to obtain solid 1 and solution 1. The solid 1 includes titanium dioxide and calcined coke.

[0045] The present invention does not have any special requirements on the composition of the chloride process titanium dioxide waste residue, and any chloride process titanium dioxide waste residue known in the art can be used.

[0046] In this invention, the preferred mass concentration of the hydrochloric acid is 20-25%, and the preferred volume ratio of water to hydrochloric acid is 1:0.2-1. This invention does not have special requirements for the total amount of water and hydrochloric acid used, as long as it is sufficient to completely leach the metal elements from the titanium dioxide waste residue from the chloride process. In an embodiment of this invention, the mass ratio of the titanium dioxide waste residue from the chloride process to the total volume of water and hydrochloric acid is 1 kg:10 L. This invention does not have special requirements for the acid leaching conditions; well-known acid leaching conditions in the art can be used.

[0047] In this invention, the reducing agent preferably includes one or more of iron powder, aluminum powder, and ascorbic acid, more preferably iron powder. In this invention, the amount of the reducing agent is preferably excessive. The reducing agent in this invention reduces oxidized metal ions, primarily reducing ferric ions to ferrous ions. In this invention, the reduction reaction time is preferably 2 hours.

[0048] The present invention does not have any special requirements for the first solid-liquid separation method; any solid-liquid separation method well known in the art can be used.

[0049] In this invention, after the first solid-liquid separation, solid 1 and solution 1 are obtained. Solid 1 comprises titanium dioxide and calcined coke, and solution 1 is an acid leaching solution containing a large number of metal ions. Preferably, solid 1 is dried and reused as a raw material in the production of titanium dioxide.

[0050] After obtaining solution 1, the present invention cools and crystallizes solution 1, followed by a second solid-liquid separation to obtain solid 2 and solution 2. The main component of solid 2 is ferrous chloride.

[0051] In this invention, the cooling crystallization temperature is preferably below 20°C, more preferably below 5°C. This invention does not have special requirements for the cooling crystallization time; it is sufficient to wait until the precipitate no longer increases. This invention precipitates ferrous chloride through cooling crystallization.

[0052] The present invention does not have any special requirements for the second solid-liquid separation method; any solid-liquid separation method well known in the art can be used.

[0053] In this invention, after the second solid-liquid separation, solid 2 and solution 2 are obtained; the main component of solid 2 is ferrous chloride, and it also contains a small amount of titanium hydrate. Preferably, solid 2 is used as a water purification agent in this invention.

[0054] After obtaining solution 2, the present invention uses extractant 1 to first extract scandium from solution 2, and after separation, organic phase 1 and raffinate 1 are obtained.

[0055] In this invention, the extractant 1 is preferably composed of P2O4, TBP and solvent oil; the volume content of P2O4 in the extractant 1 is preferably 5-25%, more preferably 8-20%, and most preferably 10%; the volume content of TBP is preferably 3-30%, more preferably 8-25%, further preferably 10-15%, and most preferably 10%.

[0056] Before the first extraction, the pH of solution 2 is preferably adjusted to 2.5. Preferredly, sodium hydroxide, calcium hydroxide, or magnesium hydroxide is used to adjust the pH of the raffinate solution 2 to the above value. In this invention, the volume ratio of solution 2 to extractant 1 is preferably 1:1.3. This invention does not have special requirements for the scandium extraction process; a process well-known in the art can be used. In this invention, the first extraction is preferably a multi-stage extraction.

[0057] After obtaining organic phase 1, the present invention performs a first back-extraction on organic phase 1 using a first sodium hydroxide solution to obtain scandium oxide. In the present invention, the concentration of the first sodium hydroxide solution is preferably 1-5 mol / L; the volume ratio of the first sodium hydroxide solution to the volume of organic phase 1 is preferably 1:1. In the present invention, the first back-extraction is preferably performed three times.

[0058] After obtaining raffinate 1, the present invention uses extractant 2 to extract zirconium and chromium in raffinate 1, and after separation, organic phase 2 and raffinate 2 are obtained.

[0059] Before the second extraction, the pH of the raffinate 1 is preferably adjusted to 3. The pH of the raffinate 1 is preferably adjusted to the above value using sodium hydroxide, calcium hydroxide, or magnesium hydroxide. In this invention, the extractant 2 is preferably composed of P507 and solvent oil; the volume content of P507 in the extractant 2 is preferably 3-25%, more preferably 10-20%, and even more preferably 12%. In this invention, the volume ratio of the raffinate 1 to the extractant 2 is preferably 1:1.6. Before the extraction, the pH of the raffinate 1 is preferably adjusted to 3. In this invention, the second extraction is preferably a multi-stage extraction, more preferably a four-stage extraction.

[0060] After obtaining organic phase 2, the present invention performs a second back-extraction on organic phase 2 with first sulfuric acid to obtain zirconium oxide and chromium oxide.

[0061] In this invention, the concentration of the first sulfuric acid is preferably 2-10 mol / L, more preferably 5-6 mol / L; the volume ratio of the first sulfuric acid to organic phase 2 is preferably 1:1.7. In this invention, the second back-extraction is preferably multi-stage back-extraction, more preferably three-stage back-extraction.

[0062] After obtaining raffinate 2, the present invention uses extractant 3 to extract niobium in raffinate 2 for the third time, and after separation, organic phase 3 and raffinate 3 are obtained.

[0063] In this invention, the extractant 3 is preferably composed of N235 and solvent oil, and the volume content of N235 in the extractant 3 is preferably 15-20%, more preferably 15%. Before extraction, the pH value of the raffinate 2 is preferably adjusted to 2.0-3.5. The pH value of the raffinate 2 is preferably adjusted to the above value using sodium hydroxide, calcium hydroxide, or magnesium hydroxide. In this invention, the volume ratio of the raffinate 2 to the extractant 3 is preferably 1:1.1. In this invention, the third extraction is preferably multi-stage extraction, more preferably 3-stage extraction.

[0064] After obtaining organic phase 3, the present invention uses oxalic acid to perform a third back-extraction on organic phase 3 to obtain niobium oxide. In the present invention, the concentration of the oxalic acid solution is preferably 10 mol / L; the volume ratio of the oxalic acid solution to organic phase 3 is preferably (1-1.5):1. In the present invention, the third back-extraction is preferably multi-stage back-extraction, more preferably three-stage back-extraction.

[0065] After obtaining raffinate 3, the present invention uses extractant 4 to extract the iron in the raffinate 3 for the fourth time, and after separation, organic phase 4 and raffinate 4 are obtained.

[0066] In this invention, the extractant 4 is preferably composed of TBP and solvent oil; the volume content of TBP in the extractant 4 is preferably 3-20%, more preferably 5-15%, and even more preferably 8%. Before the extraction, the pH value of the raffinate 3 is preferably adjusted to 2-3. The pH value of the raffinate 3 is preferably adjusted to the above value using sodium hydroxide, calcium hydroxide, or magnesium hydroxide. In this invention, the volume ratio of the raffinate 3 to the extractant 4 is preferably 1:1.4. In this invention, the fourth extraction is preferably a multi-stage extraction, more preferably a two-stage extraction. In this invention, when a product with ferric iron is required, before the fourth extraction, the invention preferably further includes adding an oxidant to the raffinate 3, followed by solid-liquid separation. In Example 2 of this invention, specifically, the raffinate 3 is mixed with manganese ore to oxidize ferrous iron to ferric iron, followed by solid-liquid separation, and then the resulting solution is subjected to a fourth extraction.

[0067] After obtaining organic phase 4, the present invention performs a fourth back-extraction on organic phase 4 using a second sodium hydroxide solution or a phosphoric acid solution to obtain an iron compound. In the present invention, the concentration of the second sodium hydroxide solution is preferably 5 mol / L; the volume ratio of the second sodium hydroxide solution to organic phase 4 is preferably 1:(2-3); the concentration of the phosphoric acid solution is preferably 5 mol / L; and the volume ratio of the phosphoric acid solution to organic phase 4 is preferably 1:2. In the present invention, the iron compound preferably includes at least one of iron oxide, iron phosphate, iron carbonate, ferric chloride, and ferrous chloride. In the present invention, the fourth back-extraction is preferably multi-stage back-extraction, more preferably two-stage back-extraction.

[0068] After obtaining the raffinate 4, the present invention uses extractant 5 to extract vanadium and manganese in the raffinate 4 for the fifth time. After separation, organic phase 5 and raffinate 5 are obtained. The organic phase 5 is then back-extracted with a second sulfuric acid solution to obtain manganese sulfate product and back-extracted organic phase 5.

[0069] In this invention, the extractant 5 is preferably composed of N1923 and solvent oil; the volume content of N1923 in the extractant 5 is preferably 3-15%, more preferably 8-12%, and even more preferably 10%. In this invention, before extraction, the pH value of the raffinate 4 is preferably adjusted to 3-5. In this invention, the volume ratio of the raffinate 4 to the extractant 5 is preferably 1:(0.9-1). In this invention, the fifth extraction is preferably a multi-stage extraction, more preferably a two-stage extraction.

[0070] In this invention, the concentration of the second sulfuric acid is preferably 10 mol / L; the volume ratio of the second sulfuric acid solution to the organic phase 5 is preferably 1:1. In this invention, the fifth back-extraction is preferably multi-stage back-extraction, more preferably two-stage back-extraction.

[0071] After obtaining the back-extracted organic phase 5, the present invention uses sodium carbonate solution to perform a sixth back-extraction on the back-extracted organic phase 5 to obtain vanadium oxide.

[0072] In this invention, the concentration of the sodium carbonate solution is preferably 10 mol / L. In this invention, the volume ratio of the organic phase 5 after back-extraction to the sodium carbonate solution is preferably 1:(0.9-1). In this invention, the manganese compound preferably includes at least one of manganese oxide, manganese phosphate, manganese carbonate, manganese chloride, and manganese sulfate. In this invention, the sixth back-extraction is preferably multi-stage back-extraction, more preferably two-stage back-extraction.

[0073] After obtaining the raffinate 5, the present invention mixes the raffinate 5 with activated carbon to adsorb and remove organic matter, then removes the activated carbon, adds an oxidant for oxidation, adjusts the pH value, and obtains polyaluminum chloride.

[0074] In this invention, the amount of activated carbon used is preferably 0.3% of the mass of the raffinate 5; the adsorption time is preferably 0.5 h. This invention utilizes activated carbon to adsorb residual dissolved oil and extractant. In this invention, the removal method of the activated carbon is preferably filtration.

[0075] In this invention, the oxidant is preferably one or more of hydrogen peroxide, sodium hypochlorite, ozone, and sodium chlorate; the amount of the oxidant is preferably excessive. The addition of the oxidant in this invention oxidizes residual iron. This invention preferably uses sodium hydroxide to adjust the pH value. This invention adjusts the pH value to 2-7 to ensure that metal ions form hydrates.

[0076] In this invention, the polyaluminum chloride can be directly used as a water purification agent.

[0077] Figure 1 A simplified diagram of the process for the comprehensive recovery of scandium, zirconium, and niobium from the hydrochloric acid leaching solution of titanium dioxide waste from the chloride process.

[0078] Figure 2 A simplified diagram of the process for the comprehensive recovery of iron, manganese, and vanadium from the hydrochloric acid leaching solution of titanium dioxide waste residue from the chloride process.

[0079] This invention designs a complete element resource utilization technology and a reasonable process to achieve resource utilization treatment; this invention produces no wastewater and zero waste residue discharge, resulting in significant energy saving and emission reduction effects; the comprehensive benefits of this invention far exceed those of existing treatment technologies, with an average comprehensive benefit of over 1,000 yuan per ton of collected dust residue.

[0080] The following detailed description of the method for the full-element resource utilization of titanium dioxide waste residue from the chloride process provided by the present invention, with reference to the embodiments, should not be construed as limiting the scope of protection of the present invention.

[0081] Example 1

[0082] (1) Weigh 2000g of titanium dioxide dust collection residue, add 7L of water and 3L of hydrochloric acid (concentration of 25%), then add 30g of reducing agent (specifically iron powder), react for 2 hours, and then perform solid-liquid separation to obtain 292g of solid 1 and 10L of solution 1.

[0083] (2) Solid 1 is mainly composed of titanium dioxide and calcined coke. After drying, it is recycled as a raw material for the production of titanium dioxide chloride. Solution 1 is cooled and crystallized at 5°C and then separated into solid and liquid to obtain solid 2 and solution 2. Solid 2 is 535g of ferrous chloride, which is used as a water purification agent. Solution 2 is 9L and transferred to the first extraction section.

[0084] (3) Adjust the pH of solution 2 to 2.5, add 12.5L of P2O4, TBP and solvent oil (of which the volume content of P2O4 is 10% and the volume content of TBP is 10%) for multi-stage extraction of scandium metal, separate the two phases to obtain 12.5L of organic phase 1 and 9L of raffinate 1, add 12.5L of 5mol / L NaOH to organic phase 1 for three back-extractions to obtain 92mg of scandium metal oxide;

[0085] (4) 9L of raffinate 1 was oxidized with H2O2 to change the metal valence state, and pH was adjusted to 3. 15L of P507 and solvent oil (of which the volume content of P507 was 12%) was added. After four stages of extraction, metal zirconium and metal chromium were extracted. Then the two phases were separated to obtain 15.2L of organic phase 2 and 8.8L of raffinate 2. 15L of H2SO4 with a concentration of 10mol / L was added to organic phase 2 and back-extracted in three stages to obtain 42g of zirconium oxide and chromium oxide.

[0086] (5) Adjust the pH of the raffinate 2 to 2.7 and add 10L of extractant N235 and solvent oil (of which N235 has a volume content of 15%). After three-stage extraction of niobium, separate the two phases to obtain 10.3L of organic phase 3 and 8.5L of raffinate 3. Add 12L of oxalic acid with a concentration of 10mol / L to organic phase 3 and back-extract organic phase 3 to obtain 92mg of niobium oxide product.

[0087] (6) Adjust the pH of the raffinate 3 to 3, add 12L of extractant TBP and solvent oil (of which the volume content of TBP is 8%), and extract metallic iron through two stages. Separate the two phases to obtain 12.3L of organic phase 4 and 8.2L of raffinate 4. Add 4.5L of 5mol / L NaOH solution to organic phase 4 and back-extract through two stages to obtain 10g of iron compound.

[0088] (7) Adjust the pH of the raffinate 4 to 5, add extractant N1923 and solvent oil totaling 8L, and perform 3-stage extraction of metallic vanadium and metallic manganese. Separate the two phases to obtain 8.2L of organic phase 5 and 8L of raffinate 5. Use 8L of 10mol / L H2SO4 to perform 2-stage back-extraction of organic phase 5 to obtain 152g of manganese sulfate. Then use 8L of 10mol / L Na2CO3 to perform 2-stage back-extraction of organic phase 5 to obtain 23g of sodium metavanadate.

[0089] (8) After the raffinate 5 is adsorbed by activated carbon, oxidized by 20% hydrogen peroxide oxidant (0.03% of total mass), and the pH value is adjusted to 4.5 with sodium hydroxide, 4.5L of polyaluminum chloride water purification agent product is obtained.

[0090] Example 2

[0091] The only difference from Example 1 is that steps (6) and (7) are different.

[0092] Step (6) is as follows:

[0093] After adding 200g of manganese ore (containing more than 70% manganese dioxide) to the raffinate 3 and mixing and stirring, solid-liquid separation was obtained to get 20g of solid 3 and 8L of solution 3. The pH was adjusted to 2, and 16L of TBP and solvent oil (of which the volume content of TBP is 8%) was used to extract metallic iron through three stages. The two phases were separated to get 16L of organic phase 4 and 8L of raffinate 4. 8L of H3PO3 with a concentration of 5mol / L was added to organic phase 4 and back-extracted through three stages to get 82g of battery-grade FePO3.

[0094] Step (7) is as follows:

[0095] Adjust the pH of raffinate 4 to 3, add 16L of N1923 and solvent oil (TBP volume content is 10%), and perform three-stage extraction of vanadium and manganese. Separate the two phases to obtain 16L of organic phase 5 and 16L of raffinate 5. Use 16L of 10mol / L H2SO4 for two-stage back-extraction of organic phase 5 to obtain 308g of manganese sulfate. Add 10L of 10mol / L Na2CO3 to organic phase 5 after manganese extraction and perform three-stage back-extraction to obtain 23.5g of sodium metavanadate. Add an oxidant to raffinate 5 to prepare a water purification agent.

[0096] As can be seen from the above embodiments, the present invention provides a method for the full-element resource utilization of titanium dioxide waste residue from the chloride process, which does not generate new waste residue and wastewater, and can achieve full-element resource utilization, thus having extremely high economic value and environmental benefits.

[0097] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for the complete resource utilization of titanium dioxide waste residue from the chloride process, characterized in that, Includes the following steps: The waste residue from the chloride process titanium dioxide was mixed with water and hydrochloric acid for acid leaching. A reducing agent was added to the resulting acid-leached material to carry out a reduction reaction. The first solid-liquid separation was performed to obtain solid 1 and solution 1. The solid 1 includes titanium dioxide and calcined coke. The solution 1 is cooled and crystallized, followed by a second solid-liquid separation to obtain solid 2 and solution 2. The main component of solid 2 is ferrous chloride. Scandium in solution 2 is first extracted using extractant 1, and after separation, organic phase 1 and raffinate 1 are obtained. Organic phase 1 is then back-extracted using a first sodium hydroxide solution to obtain scandium oxide. Extractant 1 is composed of P2O4, TBP, and solvent oil. The volume content of P2O4 in extractant 1 is 5-25%, and the volume content of TBP is 3-30%. The volume ratio of solution 2 to extractant 1 is 1:1.

3. Zirconium and chromium in the raffinate 1 are extracted a second time using extractant 2, and after separation, organic phase 2 and raffinate 2 are obtained. Organic phase 2 is then back-extracted with sulfuric acid to obtain zirconium oxide and chromium oxide. Extractant 2 is composed of P507 and solvent oil. The volume content of P507 in extractant 2 is 3-25%. The volume ratio of raffinate 1 to extractant 2 is 1:1.

6. Niobium in the raffinate 2 is extracted a third time using extractant 3, and after separation, organic phase 3 and raffinate 3 are obtained. The organic phase 3 is then back-extracted with oxalic acid to obtain metallic niobium oxide. The extractant 3 is composed of N235 and solvent oil, and the volume content of N235 in the extractant 3 is 15~20%. The volume ratio of raffinate 2 to extractant 3 is 1:1.

1. The iron in the raffinate 3 is extracted for the fourth time using extractant 4. After separation, organic phase 4 and raffinate 4 are obtained. The organic phase 4 is then back-extracted for the fourth time using a second sodium hydroxide solution or phosphoric acid solution to obtain iron compounds. The extractant 4 is composed of TBP and solvent oil. The volume content of TBP in the extractant 4 is 3-20%. The volume ratio of raffinate 3 to extractant 4 is 1:1.

4. Vanadium and manganese in the raffinate 4 are extracted for the fifth time using extractant 5. After separation, organic phase 5 and raffinate 5 are obtained. The organic phase 5 is then back-extracted for the fifth time using a second sulfuric acid solution to obtain manganese sulfate product and back-extracted organic phase 5. The extractant 5 is composed of N1923 and solvent oil. The volume content of N1923 in the extractant 5 is 3-15%. The volume ratio of raffinate 4 to extractant 5 is 1:(0.9-1). The organic phase 5 after back-extraction was subjected to a sixth back-extraction using sodium carbonate solution to obtain sodium metavanadate. The raffinate 5 is mixed with activated carbon to adsorb and remove organic matter. Then the activated carbon is removed, an oxidant is added for oxidation, and the pH value is adjusted to 2-7 to obtain polyaluminum chloride.

2. The method for resource recovery of all elements according to claim 1, characterized in that, The cooling crystallization temperature is below 20°C.

3. The method for resource recovery of all elements according to claim 1, characterized in that, The concentration of the first sodium hydroxide solution is 1~5 mol / L; the volume ratio of the first sodium hydroxide solution to organic phase 1 is 1:

1.

4. The method for resource recovery of all elements according to claim 1, characterized in that, The concentration of the first sulfuric acid is 2~10 mol / L; the volume ratio of the first sulfuric acid to organic phase 2 is 1:1.

7.

5. The method for resource recovery of all elements according to claim 1, characterized in that, The concentration of the oxalic acid solution is 2 mol / L; the volume ratio of the oxalic acid solution to organic phase 3 is 1:4.

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