A method for comprehensive utilization of tungsten-containing and lithium-containing waste residue resources

Abstract

The application discloses a kind of tungsten-containing, lithium-containing waste residue resource comprehensive utilization method.The main contents of the method are as follows: tungsten-containing waste residue, lithium-containing calcium slag and soda grinding are mixed, high-temperature roasting is carried out, and sintered material is obtained.Sintered material is leached with aqueous solution, and poor tungsten solution A and leaching residue are obtained;Poor tungsten solution A is concentrated by evaporation and acidified to obtain poor tungsten solution C;Poor tungsten solution C is adsorbed by resin, and desorbed by caustic soda solution, respectively to obtain lithium-poor solution and tungsten-rich solution;Tungsten-rich solution is acidified by sulfuric acid to obtain tungstic acid product;Lithium-poor solution is concentrated by evaporation and carbonated by soda to obtain lithium carbonate product.The application reduces the consumption of soda by introducing lithium-containing calcium slag, realizes efficient and synergistic recovery of high-value metals tungsten and lithium resources, and improves the comprehensive utilization rate of resources.

Description

Technical Field

[0001] This invention relates to the production or refining of metals and the recovery of valuable metals from metallurgical waste, specifically to a method for the comprehensive utilization of tungsten- and lithium-containing waste resources. Background Technology

[0002] Tungsten, with its high melting point and high hardness, is widely used in cemented carbide, machinery manufacturing, electronics, aerospace navigation and other fields, and is known as the "teeth of industry". However, long-term mining and APT smelting and processing have continuously produced a large amount of tungsten tailings and tungsten smelting waste, and the waste still contains a considerable amount of tungsten oxide resources. Long-term idleness not only occupies land and poses the risk of environmental leakage, but also causes metal loss.

[0003] Meanwhile, with the development of the new energy industry, the demand for lithium resources continues to rise. The processes of lithium mining and beneficiation, lithium carbonate smelting, and recycling of spent lithium batteries continuously generate large amounts of solid waste such as lithium-containing calcium slag. As a byproduct of lithium extraction, the lithium resources in this slag are often not effectively recovered, resulting in resource waste.

[0004] Currently, the industry's resource recovery solutions for tungsten slag and lithium-containing calcium slag are all single-system, independent recycling routes, lacking a co-processing approach for the two types of waste. For example, CN120945232A discloses a method for recovering tungsten from tungsten-containing calcium sulfate slag, which only treats tungsten-based solid waste separately, and prepares sodium tungstate product by roasting with the addition of sodium carbonate or sodium bicarbonate; CN118255393A discloses a method for producing sodium tungstate from tungsten-containing waste, which involves roasting tungsten waste with an oxidant, leaching with quaternary ammonium phosphate, and then adding an inorganic alkali to obtain a sodium tungstate solution.

[0005] The above-mentioned single waste residue treatment technologies have the following shortcomings: First, they can only recover tungsten or lithium separately, and cannot simultaneously dispose of two types of bulk solid waste, resulting in low solid waste disposal efficiency; Second, roasting and activating tungsten minerals requires the addition of large amounts of soda ash and acid-base reagents, resulting in high reagent consumption and high overall production costs; Third, the process only extracts a single metal, and the associated valuable components in the solid waste are not recovered simultaneously, resulting in poor resource utilization; Fourth, the process generates a large amount of saline waste liquid, which can easily cause secondary pollution if there is no supporting recycling system.

[0006] Current technologies have not proposed an integrated recovery scheme that utilizes the co-calcination of lithium-containing calcium slag and tungsten waste slag, and cannot leverage the components of lithium-containing calcium slag itself to reduce soda ash consumption and simultaneously extract tungsten and lithium bimetals. This invention takes the co-utilization of two types of industrial waste slag as its core innovative idea. It co-calcines lithium-containing calcium slag, tungsten waste slag, and soda ash. The calcium carbonate in the lithium-containing calcium slag reacts with the silica and silicates in the tungsten waste slag, reducing sodium silicate formation and improving soda ash utilization efficiency. Furthermore, the lithium salts such as lithium hydroxide or lithium carbonate in the lithium-containing calcium slag react with the tungsten oxide or tungstate in the tungsten waste slag, converting them into water-soluble lithium tungstate. This significantly increases the lithium recovery rate from the lithium-containing calcium slag, reduces soda ash consumption, and co-recovers lithium carbonate, achieving comprehensive resource recovery and utilization. Summary of the Invention

[0007] In view of the technical problems of the existing technology, such as only being able to process tungsten-containing waste residue or lithium-containing calcium slag separately, requiring a large amount of acid and alkali reagents, being unable to recover tungsten and lithium in a coordinated manner, having low resource utilization rate and high environmental pressure, this invention provides a method for the comprehensive utilization of tungsten-containing and lithium-containing waste residue resources.

[0008] The technical solution adopted in this invention is as follows:

[0009] A method for comprehensive utilization of tungsten- and lithium-containing waste residue resources includes the following steps:

[0010] S1. Tungsten-containing waste residue, lithium-containing calcium residue and soda ash are mixed and ground to obtain mixed roasting material, and then roasted to obtain sintered material containing sodium tungstate and lithium tungstate;

[0011] S2. The sintered material obtained in step S1 is treated by water leaching, and solid-liquid separation is performed to obtain iron-rich leaching residue and tungsten-poor solution A containing dissolved tungsten and lithium.

[0012] S3. The tungsten-poor solution A obtained in step S2 is concentrated, acidified, and then adsorbed and separated using an alkaline anion exchange resin to obtain a lithium-poor solution and a tungsten-rich solution, respectively.

[0013] S4. Prepare tungstic acid product by acidification and precipitation of the tungsten-rich solution obtained in step S3.

[0014] S5. After concentrating the lithium-poor solution obtained in step S3, add soda ash to carbonize and obtain lithium carbonate product. The condensate generated by the evaporation process is returned to the water immersion process in step S2 for recycling. In step S3, the tungsten-poor solution A is evaporated and concentrated to obtain a tungsten-poor solution B with a tungsten metal concentration of 5 g / L to 15 g / L. The pH value is then adjusted to 3 to 5 with sulfuric acid to obtain a tungsten-poor solution C. The residual tungsten in the lithium-poor solution after adsorption by alkaline anion exchange resin is ≤0.5 mg / L. The tungsten-saturated resin is desorbed with a caustic alkali solution with a mass fraction of 5% to 20% to obtain a tungsten-rich solution with a tungsten metal concentration of 100 g / L to 250 g / L.

[0015] Furthermore, the tungsten-containing waste residue is APT smelting waste residue or tungsten-containing ore slag, wherein the mass fraction of tungsten oxide is 0.5% to 5.0%. The lithium-containing calcium slag is lithium-containing calcium carbonate solid slag produced from spodumene, lepidolite, or lithium extraction from waste lithium batteries, wherein the mass fraction of metallic lithium is 0.3% to 5.0%. Both types of waste residue are large-scale solid wastes in the metallurgical and new energy industries. Conventional processes only store them separately or recover a single metal. This invention is suitable for both types of low-grade metal-containing waste residues, eliminating the need for pre-purification and enrichment of raw materials. It can directly dispose of industrial by-product solid waste, which helps to solve multiple environmental and resource problems such as land occupation, heavy metal leakage, and loss of valuable metals caused by the storage of solid waste in these two industries.

[0016] Furthermore, in step S1, the mixed roasting material comprises, by mass percentage, 60%–90% tungsten-containing waste residue, 5%–30% lithium-containing calcium slag, and 1%–20% soda ash. The tungsten-containing waste residue serves as the main raw material, ensuring the scale of tungsten product output. The lithium-containing calcium slag, as a functional auxiliary material, simultaneously achieves the triple effects of silicon inhibition, tungsten activation, and lithium release through its own calcium and lithium salts. Soda ash acts only as an auxiliary activator. Due to the synergistic effect of the lithium-calcium slag, the proportion of soda ash added can be significantly reduced, thereby significantly reducing the consumption of soda ash reagents.

[0017] Furthermore, in step S1, the roasting temperature is 700–1200℃, and the roasting time is 1–4 hours. During the roasting process, the lithium salt in the lithium-calcium slag reacts with the tungsten oxide in the tungsten-containing waste slag to generate water-soluble lithium tungstate. The calcium-containing component can inhibit the formation of sodium silicate, reducing the consumption of soda ash. The above temperature range and holding time can ensure that two types of solid-phase synergistic reactions occur fully: First, Li2CO3, LiOH, and WO3 in the lithium-calcium slag react in situ with each other to generate water-soluble Li2WO4, simultaneously activating tungsten minerals and dissolving lithium components; Second, CaCO3 and CaO in the calcium slag preferentially react with SiO2 and silicates in the tungsten slag to generate an inert calcium silicate solid phase, avoiding the reaction of SiO2 with soda ash to generate ineffective sodium silicate, which consumes soda ash. The dual synergistic reactions jointly reduce the amount of soda ash added, which is significantly different from the existing single tungsten slag roasting process in terms of mechanism.

[0018] The main forms of tungsten in tungsten-containing waste slag are tungsten trioxide (WO3), calcium tungstate (CaWO4), and iron tungstate (FeWO4). The main forms of lithium in lithium-containing calcium slag are lithium carbonate (Li2CO3) and lithium hydroxide (LiOH). Sodium and lithium are elements in the same group and have similar physicochemical properties. During roasting, the above-mentioned tungsten components undergo the following metathesis reactions with sodium and lithium salts, mainly producing soluble sodium tungstate or lithium tungstate.

[0019] I. The tungsten component in tungsten-containing waste reacts with sodium carbonate, as shown in the following reaction formula: (1) Reaction of tungsten trioxide with sodium carbonate: WO3 + Na2CO3 → Na2WO4 + CO2↑, (2) Reaction of calcium tungstate with sodium carbonate: CaWO4+ Na2CO3 → Na2WO4 + CaCO3, (3) The reaction of ferric tungstate with sodium carbonate under an oxidizing atmosphere: 2FeWO4+ 2Na2CO3 + 1 / 2O2→ 2Na2WO4 + Fe2O3 + 2CO2↑.

[0020] II. The tungsten component in tungsten-containing waste residue reacts with the lithium component in lithium-containing calcium slag, as shown in the following reaction formula: (1) Reaction of tungsten trioxide with lithium carbonate: WO3 + Li2CO3 → Li2WO4 + CO2↑, (2) Reaction of calcium tungstate with lithium carbonate: CaWO4+ Li2CO3 → Li2WO4 + CaCO3, (3) The reaction of ferric tungstate with sodium carbonate under an oxidizing atmosphere: 2FeWO4+ 2Li2CO3 + 1 / 2O2→ 2Li2WO4 + Fe2O3 + 2CO2↑, (4) Reaction of tungsten trioxide with lithium hydroxide: WO3 + 2LiOH → Li2WO4 + H2O, (5) Reaction of calcium tungstate with lithium hydroxide: CaWO4+ 2LiOH + CO2 → Li2WO4 + CaCO3+ H2O, (6) Reaction of ferric tungstate with lithium hydroxide under an oxidizing atmosphere: 2FeWO4+ 4LiOH + 1 / 2O2→ 2Li2WO4 + Fe2O3 + 2H2O.

[0021] In addition to the main reactions mentioned above, since the tungsten-containing waste slag also contains a small amount of silicates and arsenates, the calcium carbonate and other components in the calcium slag can fix them, forming insoluble calcium silicate and calcium arsenate, reducing the introduction of impurities in subsequent processes. The reactions are as follows: CaCO3 + SiO2→ CaSiO3 + CO2↑, 2Na3AsO4 + 3CaCO3 → Ca3(AsO4)2+ 3Na2CO3.

[0022] Furthermore, the water leaching employs a 1-3 stage countercurrent pure water leaching process, with a pure water to sinter liquid-solid mass ratio of 1-5:1, a leaching temperature of 60-100℃, a leaching pressure of 0.1MPa-0.2MPa, and a leaching time of 0.5-2h. Countercurrent leaching allows for reverse contact between fresh pure water and high-tungsten-lithium sinter, progressively increasing the tungsten and lithium concentrations in the leaching solution, significantly improving the leaching metal leaching rate. The medium temperature and low pressure conditions facilitate accelerated dissolution and diffusion of sodium tungstate and lithium tungstate, shortening the leaching time. Pure water leaching does not introduce exogenous impurities such as chlorine, fluorine, and nitrate, reducing the purification and impurity removal load on downstream tungsten and lithium products.

[0023] Furthermore, sulfuric acid is added to the tungsten-rich solution for acidification and precipitation. The pH value of the system is controlled at 1-3, the temperature at 10-50℃, and the pressure at normal, to precipitate tungstic acid products.

[0024] Furthermore, the lithium-poor solution is evaporated and concentrated to obtain a lithium-rich solution; when the lithium metal concentration in the lithium-rich solution is <4 g / L, it is directly refluxed to the lithium-poor solution feed end for recycling; when the lithium metal concentration in the lithium-rich solution is ≥4 g / L, it is sent to the soda ash carbonation process to prepare lithium carbonate.

[0025] Furthermore, the lithium precipitation mother liquor is processed in two separate streams: the first stream mother liquor is returned to be mixed with the lithium-poor solution for recycling and lithium recovery, while the second stream mother liquor is sent to the evaporation and crystallization section to precipitate solid sodium sulfate. The first stream mother liquor is recycled to recover dissolved residual lithium, improving the overall lithium recovery rate; the second stream mother liquor is evaporated and crystallized separately, and the sodium sulfate generated from neutralization and carbonization is recovered and sold as industrial salt, realizing the resource utilization of salt and eliminating the environmental risks of soil and water salt pollution caused by the direct discharge of high-salt mother liquor. All solid waste and waste liquid are converted into marketable products.

[0026] In the above method, the roasting, water leaching, and acidification stages all employ atmospheric pressure and low-temperature reaction conditions, eliminating the need for high-pressure equipment and high-temperature melting conditions. All condensate generated during the evaporation and crystallization processes is recovered and reused in the water leaching stage, achieving a closed-loop recycling of process wastewater. The entire process operates without high pressure or demanding melting conditions; general-purpose metallurgical atmospheric pressure reactors, rotary kilns, and leaching tanks can complete the entire process. Equipment investment and maintenance costs are significantly lower than those of high-pressure hydrothermal and high-temperature melting recovery processes. All condensate is free of salt and heavy metal impurities, and 100% is reused in the initial water leaching stage. No process wastewater is discharged externally during the production process, making it environmentally friendly.

[0027] The above method can simultaneously treat two types of industrial solid waste: tungsten-containing slag from tungsten mines or APT smelting, and lithium-containing calcium slag from lithium mines or spent lithium batteries. The entire process simultaneously produces three products: tungstic acid, lithium carbonate, and sodium sulfate. It not only disposes of bulk metallurgical solid waste but also recovers two strategic metals, tungsten and lithium, reducing the overall amount of soda ash required. Existing technologies can only process tungsten slag or lithium slag individually, with each production line producing only a single metal product. This invention employs a co-roasting integrated process, where a single production line simultaneously disposes of two types of solid waste and co-produces three high-value products, significantly increasing the scale of solid waste treatment and the economic benefits per unit of waste slag. Relying on the co-activation mechanism of lithium-calcium slag, it reduces soda ash consumption at the source, and the reagent cost is significantly lower than traditional single-slag roasting processes, combining environmental benefits, resource benefits, and production cost advantages.

[0028] The beneficial effects of this invention are as follows:

[0029] (1) The present invention uses tungsten-containing waste residue, lithium-containing calcium slag and soda ash as ternary materials for co-calcination. It relies on the lithium salt in the lithium-containing calcium slag and the calcium-containing components to simultaneously complete the activation of tungsten minerals and inhibit the ineffective consumption of soda ash by sodium silicate, which significantly reduces the amount of soda ash reagent added. It can also release the lithium components in the calcium slag at the same time, and simultaneously improve the leaching recovery rate of the two valuable metals, tungsten and lithium.

[0030] (2) This invention achieves deep separation of tungsten and lithium without extractant through selective adsorption of acid-base anion exchange resin. The whole integrated process can simultaneously produce two high-value metal products, tungstic acid and lithium carbonate, and can also produce sodium sulfate as a by-product. Compared with the single waste residue recycling process, it greatly improves the resource utilization benefits of solid waste and the comprehensive utilization rate of resources.

[0031] (3) The present invention is equipped with a multi-stage circulation system of lithium-rich solution graded circulation, lithium precipitation mother liquor dual-branch diversion and recovery, and evaporation condensate full reuse. This system not only reduces steam energy consumption in the evaporation process, but also recovers residual lithium salts in the mother liquor and sulfates in the system, realizing closed-loop circulation of production wastewater and eliminating the environmental risks caused by the discharge of high-salt waste liquid.

[0032] (4) The entire process of roasting, leaching and acidification of this invention is carried out under normal pressure and low temperature conditions. No special equipment for high pressure and high temperature melting is required. Conventional metallurgical equipment can complete the production. It can simultaneously dispose of two types of large-scale solid waste: tungsten smelting or mine waste slag and lithium ore or lithium calcium slag from waste lithium batteries. The equipment investment and daily operation and maintenance costs are lower, making it suitable for large-scale industrial promotion. Attached Figure Description

[0033] Figure 1 This is a flowchart of the process flow of the present invention. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to specific embodiments, but the present invention is not limited thereto.

[0035] The raw materials are uniformly described in the following examples:

[0036] Tungsten-containing waste residue: APT smelting waste residue, tungsten oxide mass fraction 2.2%;

[0037] Lithium-containing calcium slag: A lithium-containing calcium carbonate solid slag produced as a byproduct of lithium extraction from waste lithium batteries, with a lithium metal mass fraction of 1.8%.

[0038] The basic anion exchange resin selected is a macroporous, weakly basic acrylic anion exchange resin.

[0039] Example 1

[0040] S1. Mixed roasting: Take 100 kg of total material according to the mass percentages of 80% tungsten waste residue, 15% lithium calcium slag and 5% soda ash, grind and mix them together; keep roasting at 900℃ for 2.5 h to obtain sintered material.

[0041] S2. Countercurrent pure water leaching: The sintered material was leached using a two-stage countercurrent pure water process, with a pure water to sintered material liquid-to-solid mass ratio of 3:1, a leaching temperature of 80℃, a leaching pressure of 0.15MPa, and a leaching time of 1 hour. Solid-liquid separation yielded iron-rich leaching residue and tungsten-poor solution A. Analysis showed that the tungsten concentration in tungsten-poor solution A was 2.84 g / L, and the lithium metal concentration was 1.6 g / L.

[0042] S3. Concentration, acid adjustment, and resin adsorption separation: Tungsten-poor solution A was evaporated and concentrated to a tungsten concentration of 13.2 g / L to obtain tungsten-poor solution B. The pH was adjusted to 4 with concentrated sulfuric acid to obtain tungsten-poor solution C. Tungsten was adsorbed into a D314 resin column. After the resin adsorption was completed, the lithium-poor solution flowed out, and the residual tungsten concentration was measured to be 0.26 mg / L. The saturated resin was desorbed using a 12% caustic alkali solution to obtain a tungsten-rich solution with a tungsten concentration of 112.32 g / L.

[0043] S4. Preparation of tungstic acid by acidification: Take a tungsten-rich solution, adjust the pH to 2 with sulfuric acid, precipitate at 25℃ and normal pressure, filter, wash and dry to obtain tungstic acid product. The tungsten precipitation recovery rate is 87.11% and the purity of tungstic acid is 80.52%.

[0044] S5, Lithium Concentration and Carbonization, Mother Liquor Diversion, and Water Circulation: The lithium-poor solution is evaporated and concentrated, and the lithium concentration in the lithium-rich solution is measured to be 6.2 g / L, meeting the carbonation standard. Soda ash is added for carbonation precipitation, resulting in solid lithium carbonate. The lithium precipitation mother liquor is divided into two streams: 70% of the mother liquor from the first stream is recycled into the lithium-poor solution, and 30% of the mother liquor from the second stream is sent for evaporation and crystallization to precipitate sodium sulfate. All condensate from the evaporation process is returned to the S2 leaching process for reuse. Testing shows that the overall lithium carbonate recovery rate is 93.2%, and the entire process generates no external wastewater discharge.

[0045] Example 2

[0046] The calcination material ratio is as follows: 85% tungsten waste residue, 5% lithium-calcium slag, and 10% soda ash by mass percentage. The remaining process and parameters are exactly the same as in Example 1.

[0047] Example 3

[0048] The calcination material ratio is 90% tungsten waste residue and 10% soda ash by mass percentage, and the remaining process and parameters are exactly the same as in Example 1.

[0049] Example 4

[0050] The calcination material ratio is based on 100% by mass of tungsten-containing waste residue, and the remaining process and parameters are exactly the same as in Example 1.

[0051] Example 5

[0052] The material was calcined at 800℃ for 2.5 hours to obtain the sintered material. The remaining processes and parameters were exactly the same as in Example 1.

[0053] Example 6

[0054] The material was calcined at 1000℃ for 2.5 hours to obtain the sintered material. The remaining processes and parameters were exactly the same as in Example 1.

[0055] The experimental results for each embodiment are shown in Table 1.

[0056] Table 1 Experimental results of each embodiment

[0057]

[0058] As can be seen from the experimental data in Table 1, the technical advantages of the synergistic roasting of this invention are:

[0059] (1) Comparing Examples 1 and 2 (with lithium-containing calcium slag) with Examples 3 and 4 (without lithium-containing calcium slag): only the tungsten leaching concentration and tungsten precipitation recovery rate of the tungsten slag and soda ash system decreased significantly, and there was no lithium resource recovery; when combined with lithium-containing calcium slag, tungsten and lithium were leached simultaneously and efficiently, and the lithium carbonate recovery rate could reach up to 93.2%, proving that lithium-containing calcium slag can synergistically activate tungsten minerals and release lithium components simultaneously.

[0060] (2) Comparing Examples 1, 5, and 6 (different roasting temperatures), it can be seen that the tungsten-lithium recovery effect is significantly reduced when roasted at 800℃. The comprehensive recovery index of tungsten and lithium is optimal in the range of 900-1000℃. The medium and high temperature range can ensure that the solid phase synergistic reaction can proceed fully.

[0061] (3) The residual tungsten in the lithium-poor solution after resin adsorption is ≤0.33mg / L, which reflects the high selectivity of alkaline anion exchange resin for tungsten separation and can avoid excessive tungsten impurities in lithium products.

[0062] (4) Overall data proves that the ternary synergistic roasting system of tungsten-containing waste residue, lithium-containing calcium slag and soda ash can simultaneously achieve efficient recovery of tungsten and lithium bimetals compared with the single tungsten slag roasting process, and has unexpected resource utilization effect.

Claims

1. A method for comprehensive utilization of tungsten- and lithium-containing waste residue resources, characterized in that, Includes the following steps: S1. Tungsten-containing waste residue, lithium-containing calcium slag and soda ash are mixed and ground to obtain mixed roasting material, and then roasted to obtain sintered material containing sodium tungstate and lithium tungstate; S2. The sintered material obtained in step S1 is treated by water leaching, and solid-liquid separation is performed to obtain iron-rich leaching residue and tungsten-poor solution A containing dissolved tungsten and lithium. S3. The tungsten-poor solution A obtained in step S2 is concentrated, acidified, and then adsorbed and separated using an alkaline anion exchange resin to obtain a lithium-poor solution and a tungsten-rich solution, respectively. S4. Prepare tungstic acid product by acidification and precipitation of the tungsten-rich solution obtained in step S3. S5. After concentrating the lithium-poor solution obtained in step S3, add soda ash for carbonation to obtain lithium carbonate product. The condensate generated during the entire evaporation process is returned to the water immersion process in step S2 for recycling. In step S3, the tungsten-poor solution A is evaporated and concentrated to obtain a tungsten-poor solution B with a tungsten metal concentration of 5 g / L to 15 g / L. The pH value is then adjusted to 3 to 5 with sulfuric acid to obtain a tungsten-poor solution C. The residual tungsten in the lithium-poor solution after adsorption by alkaline anion exchange resin is ≤0.5 mg / L. The tungsten-saturated resin is desorbed with a caustic alkali solution with a mass fraction of 5% to 20% to obtain a tungsten-rich solution with a tungsten metal concentration of 100 g / L to 250 g / L.

2. The method for comprehensive utilization of tungsten- and lithium-containing waste residue resources according to claim 1, characterized in that: The tungsten-containing waste residue is APT smelting waste residue or tungsten-containing slag, wherein the mass fraction of tungsten oxide is 0.5% to 5.0%. The lithium-containing calcium slag is lithium-containing calcium carbonate solid slag produced in the lithium extraction process of spodumene, lepidolite, or waste lithium batteries, wherein the mass fraction of metallic lithium is 0.3% to 5.0%.

3. The method for comprehensive utilization of tungsten- and lithium-containing waste residue resources according to claim 1, characterized in that: In step S1, the mixed roasting material includes, by mass percentage, 60%–90% tungsten-containing waste residue, 5%–30% lithium-calcium slag, and 1%–20% soda ash.

4. The method for comprehensive utilization of tungsten- and lithium-containing waste residue resources according to claim 1, characterized in that: In step S1, the calcination temperature is 700–1200℃ and the calcination time is 1–4 hours.

5. The method for comprehensive utilization of tungsten- and lithium-containing waste residue resources according to claim 1, characterized in that: In step S2, the water leaching is carried out using 1 to 3 stages of countercurrent pure water leaching, the mass ratio of pure water to sintered material liquid to solid is 1 to 5:1, the leaching temperature is 60 to 100°C, the leaching pressure is 0.1 MPa to 0.2 MPa, and the leaching time is 0.5 to 2 hours.

6. The method for comprehensive utilization of tungsten- and lithium-containing waste residue resources according to claim 1, characterized in that: In step S4, the conditions for acidification precipitation are: controlling the pH value of the system to be 1-3, the temperature to be 10-50℃, and the pressure to be normal.

7. The method for comprehensive utilization of tungsten- and lithium-containing waste residue resources according to claim 1, characterized in that: In step S5, the lithium-poor solution is evaporated and concentrated to obtain a lithium-rich solution; when the lithium metal concentration in the lithium-rich solution is <4g / L, it is directly refluxed to the lithium-poor solution feed end for recycling; when the lithium metal concentration in the lithium-rich solution is ≥4g / L, it is sent to the soda ash carbonation process to prepare lithium carbonate.

8. The method for comprehensive utilization of tungsten- and lithium-containing waste residue resources according to claim 1, characterized in that: In step S5, the lithium precipitation mother liquor produced by carbonization is divided into two branches for processing: the first branch and the second branch. The mother liquor from the first branch is returned to be mixed with the lithium-poor solution for recycling and lithium recovery. The mother liquor from the second branch is sent to the evaporation and crystallization section to precipitate solid sodium sulfate.

9. The method for comprehensive utilization of tungsten- and lithium-containing waste residue resources according to claim 1, characterized in that: The roasting, water immersion, and acidification sections all operate at atmospheric pressure. All condensate generated during the evaporation and crystallization processes is recycled and reused in the water immersion section, achieving a closed-loop circulation of process wastewater.

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