A combined beneficiation and smelting method for treating weathered tungsten

Abstract

The present invention discloses a combined treatment method for the beneficiation of weathered tungsten ore, belonging to the field of mineral processing technology. The method comprises the following steps: subjecting weathered or semi-weathered tungsten ore to cyclone classification to obtain fine-grained tungsten ore and ultrafine-grained tungsten mud; flotation of the fine-grained tungsten ore using a reagent system comprising a metal-based colloidal collector to obtain a high-grade tungsten concentrate, which is then subjected to a hydrometallurgical smelting process; and selectively flocculating and settling the ultrafine-grained tungsten mud using a functionalized modified polyacrylamide flocculant to obtain a low-grade tungsten concentrate, which is then subjected to a sodium roasting-water leaching process to obtain a sodium tungstate solution. The method can achieve deep enrichment and recovery of tungsten elements in weathered or semi-weathered tungsten ore, promote the clean, efficient, and sustainable utilization of tungsten ore resources, and has significant economic benefits.

Description

Technical Field

[0001] The invention relates to a method for treating weathered tungsten and semi-weathered tungsten ore, in particular to a combined beneficiation and smelting method for treating weathered tungsten, and belongs to the technical field of mineral processing and metallurgy. Background Art

[0002] Currently, over 20 types of tungsten minerals and tungsten-containing minerals have been discovered, but at this stage, only primary wolframite and scheelite have good economic mining value. Tungsten minerals are mainly divided into primary tungsten ore, semi-weathered tungsten ore, and weathered tungsten ore. Primary tungsten minerals are divided into wolframite and scheelite; semi-weathered tungsten minerals are generally believed to be produced by hydrothermal or supergene alteration of primary tungsten minerals, rather than by atmospheric weathering. Typical semi-weathered tungsten minerals include hydrotungstenite, calceolite, and tungstenite; weathered tungsten ore refers to a type of tungsten ore formed by the reorganization of the mineral composition and chemical composition of the surface layer of primary tungsten ore under the influence of the atmosphere, water, and organisms. Compared with primary tungsten ore, the mineral composition and properties of weathered tungsten ore and semi-weathered tungsten ore change significantly, and the tungsten content of weathered tungsten ore increases. However, due to weathering, this type of ore is prone to over-grinding during the crushing and grinding stage of mineral processing, resulting in a fine particle distribution state, a significant increase in specific surface area, an inevitable increase in ions in the slurry, and a reduced probability of collision and adhesion with bubbles. The separation efficiency of conventional flotation and gravity separation processes is greatly reduced. The presence of weathered tungsten ore seriously affects the enrichment of tungsten during the processing process, resulting in a lower tungsten recovery rate.

[0003] With the continuous depletion of easily selectable tungsten resources, the recycling of weathered and semi-weathered tungsten ores is becoming increasingly urgent. Investigations have found that the grade of weathered and semi-weathered tungsten ores is generally higher than that of primary tungsten ores. To ensure the efficient development and utilization of resources, the utilization of such resources is of great significance. However, most weathered and semi-weathered tungsten ores are extremely difficult to select and cannot meet the minimum technical indicators required for resource development and utilization. The typical characteristics of valuable tungsten minerals in weathered tungsten ores are their low mass and large specific surface area, which makes their efficient separation difficult. Flotation separation technology, as the main separation technology, has achieved a breakthrough in the lower limit of mineral flotation particle size by increasing particle size and reducing bubble size. It is one of the key technologies for the efficient and comprehensive utilization of fine-grained minerals in the future. In the existing technology, there are few flotation technologies for weathered tungsten ores. Chinese patent CN103272682A discloses a pretreatment process method specifically for fine weathered tungsten ores before flotation. In order to solve the problem that the weathered tungsten ores have extremely fine embedded particles (most of which are distributed below 10μm) and are difficult to recover by flotation, a treatment method using high-concentration slurry shear flocculation stirring and high-speed jet premineralization is designed to pretreat the fine weathered tungsten ores before flotation. The method has good results and better realizes the flotation recovery of weathered tungsten ores. The flotation recovery rate can reach more than 50%, and the concentrate grade can reach more than 10%. The tungsten concentrate recovered by this patented technology has low grade and low recovery rate, and does not involve tungsten smelting technology.

[0004] In summary, it is urgent to develop a method of combined beneficiation and smelting for synergistic extraction based on the basic characteristics of weathered tungsten ore / semi-weathered tungsten ore. Summary of the Invention

[0005] In view of the problem that easy-to-select tungsten ore resources are becoming increasingly depleted and the current beneficiation technology is difficult to process weathered and semi-weathered tungsten ores, the purpose of the present invention is to provide a combined beneficiation and smelting treatment method for weathered tungsten ore. This method finely classifies semi-weathered or weathered tungsten ores and adopts different beneficiation methods according to the respective characteristics of fine-grained tungsten minerals and ultra-fine-grained tungsten mud, so as to achieve efficient and comprehensive recovery of valuable tungsten minerals in difficult-to-select weathered or semi-weathered tungsten ores, thereby improving the comprehensive utilization rate of tungsten resources.

[0006] In order to achieve the above technical objectives, the present invention provides a combined beneficiation and smelting method for weathered tungsten ore, which comprises the following steps:

[0007] 1) Classify the weathered or semi-weathered tungsten ore through cyclone classification to obtain fine-grained tungsten ore and ultrafine-grained tungsten mud;

[0008] 2) flotating the fine-grained tungsten ore using a reagent system comprising a metal-based colloidal collector to obtain a high-grade tungsten concentrate, which enters a hydrometallurgical smelting process;

[0009] 3) The ultrafine tungsten mud is selectively flocculated and settled by a functionalized modified polyacrylamide flocculant to obtain a low-grade tungsten concentrate, and the low-grade tungsten concentrate is subjected to a sodium roasting-water leaching process to obtain a sodium tungstate solution; the functionalized modified polyacrylamide flocculant is a polyacrylamide having at least one functional group selected from the group consisting of carboxyl, thiol, amino, sulfonic acid, and hydroxamic acid grafted onto the main chain.

[0010] The combined beneficiation and smelting treatment method for weathered tungsten ore provided by the present invention mainly involves finely classifying weathered or semi-weathered tungsten ore, and the fine-grained tungsten minerals and ultra-fine-grained tungsten mud obtained by classification are respectively separated by flotation using a metal-based colloidal collector and selective flocculation-separation based on functionalized modified polyacrylamide to achieve efficient enrichment and simultaneous effective recovery of valuable tungsten minerals, thereby producing high-grade and low-grade tungsten concentrate products. The high-grade tungsten concentrate enters the conventional tungsten hydrometallurgical process, while the low-grade tungsten concentrate is efficiently extracted using the "sodium roasting-water leaching" process.

[0011] Due to the characteristics of difficult-to-separate weathered or semi-weathered tungsten ores, such as easy over-grinding, fine particle size, low mass, and large specific surface area, hydrocyclones are first used for fine classification to separate fine-grained tungsten minerals that can be directly floated from ultrafine tungsten mud that is difficult to directly recover using conventional mineral processing methods. The key to recovering fine-grained tungsten minerals is to use metal-based colloidal collectors to enhance flotation. This can achieve targeted adsorption of oxygen atoms on the surface of tungsten minerals through metal ions, thereby achieving targeted regulation of surface roughness, enhancing the hydrophilicity and hydrophobicity differences on the mineral surface, and achieving efficient recovery. This high-grade tungsten concentrate can be recovered through traditional hydrometallurgical smelting. The key to recovering ultrafine tungsten mud that is difficult to extract directly is to use functionalized modified polyacrylamide as a flocculant. By grafting specific functional groups with targeted effects on the surface of ultrafine tungsten mud onto the main chain of a conventional flocculant, efficient selective flocculation of the ultrafine tungsten mud can be achieved, and then other fine mud gangue minerals can be separated by sedimentation. This part of low-grade tungsten concentrate can be efficiently extracted from tungsten by "sodium roasting-water leaching" by introducing sodium roasting reagents.

[0012] As a preferred embodiment, the cyclone classification process has a particle size range of 5 to 10 μm. The resulting fine-grained tungsten minerals meet the requirement that the mass content of the +5 μm particle size is ≥50%, and WO₃₀₆ ...

[0013] As a preferred solution, the metal-based colloidal collector is formed by the coordination assembly of hydroxamic acid organic ligands and divalent or higher metal ions. As a more preferred solution, the divalent or higher metal ions include Pb 2+ , Ca 2+ 、Cu 2+ Mg 2+ 、Zn 2+ 、Mn 2+ 、Ni 2+ 、Fe 2+ 、Fe 3+ and La 3+At least one of the following. As a preferred embodiment, the hydroxamic acid organic ligand includes at least one of benzohydroxamic acid, salicylic hydroxamic acid, octyl hydroxamic acid, naphthyl hydroxamic acid, and benzenesulfonyl hydroxamic acid. As a preferred embodiment, the coordination molar ratio of the divalent or higher metal ion to the hydroxamic acid ligand is 1:(1-16). Metal-based colloidal collectors are metal-organic complexes with a unique three-dimensional structure formed by coordination assembly between metal ions and hydroxamic acid organic ligands. Their LUMO orbitals are primarily contributed by the high-valent central metal ion, while the HOMO orbitals on the surface of weathered tungsten minerals are primarily contributed by the O-2p orbitals at the top of the valence band. Conventional tungsten ore flotation collectors, such as fatty acids, primarily utilize their carboxylic acid groups to act on the active sites of metal ions on the surface of tungsten minerals. However, metal-organic complexes can target oxygen atoms on the surface of tungsten minerals through their metal groups, achieving targeted regulation of surface roughness, thereby enhancing the hydrophilic and hydrophobic properties of the mineral surface and enhancing flotation recovery.

[0014] As a preferred embodiment, the flotation process includes one roughing step, at least three cleaning steps, and at least two scavenging steps. As a more preferred embodiment, the roughing agent system includes: sodium carbonate as a pH adjuster to 8.5-10.5, 100-200 g / t of salinized water glass inhibitor, 1000-1500 g / t of metal-based colloidal collector, and 40-60 g / t of No. 2 oil frother. The cleaning and scavenging agent systems are halved in order. An example of salinized water glass is Al-Na2SiO3.

[0015] As a preferred embodiment, the process of selective flocculation and sedimentation of the ultrafine tungsten sludge is as follows: the ultrafine tungsten sludge is first dispersed by adding a dispersant, then a functionalized modified polyacrylamide flocculant is added to the sludge to perform shear flocculation and hydrophobic aggregation under high-speed stirring, and finally sedimentation and separation. Further preferably, the slurry concentration is controlled within the range of 30-60 wt.% during the flocculation and sedimentation process. As a more preferred embodiment, the dispersant is at least one of water glass, sodium hexametaphosphate, sodium tripolyphosphate, sodium pyrophosphate, sodium lauryl sulfate, polyethylene glycol fatty acid esters, methyl amyl alcohol, guar gum, and carboxymethyl cellulose. As a more preferred embodiment, the amount of the dispersant used is 500-2000 g / t.

[0016] As a preferred solution, the dosage of the functionalized modified polyacrylamide flocculant is 10 to 100 g / t. During the flocculation and sedimentation process of the present invention, under the action of the dispersant and flocculant, combined with appropriate stirring intensity, the optimal flocculation and sedimentation effect is achieved. The dispersant used can highly disperse the ultrafine tungsten mud, while the functionalized modified polyacrylamide flocculant can selectively adsorb on the surface of the tungsten ore, achieving hydrophobic agglomeration between the tungsten ores. The high-speed stirring action provides sufficient energy input to the ultrafine tungsten mud to overcome the electrostatic repulsion and energy barriers between particles, achieving shear flocculation and hydrophobic agglomeration of the ultrafine components of the weathered tungsten, and then separating other fine-grained gangue minerals through sedimentation.

[0017] As a preferred solution, the sodiumization roasting-water leaching process involves sequentially mixing, roasting, crushing, grinding, and leaching sodium salt and low-grade tungsten concentrate to produce a sodium tungstate solution. The sodium salt, acting as an additive, is evenly mixed with the low-grade tungsten concentrate, which helps improve the efficiency of the high-temperature solid-phase reaction. The presence of the sodium salt at high temperatures promotes the decomposition and conversion of tungsten-containing minerals, converting difficult-to-leach tungsten ore into water-soluble sodium tungstate. The roasted product is then crushed and ground to an appropriate particle size (-0.074 mm), efficiently extracted using a circulating water leaching method, and the leached residue is filtered to remove the resulting leachate, which is the sodium tungstate aqueous solution.

[0018] As a more preferred solution, the sodium salt includes at least one of Na2SiO3, Na2SiO3·5H2O, and Na2SiO3·9H2O. Further preferred sodium salts include Na2SiO3·5H2O and / or Na2SiO3·9H2O, with Na2SiO3·9H2O being the most preferred. Sodium silicate with crystalline water is used, which removes crystalline water at high temperatures and quickly forms nano-sized sodium silicate that coats the mineral surface, exhibiting higher reactivity. The reason sodium silicate or sodium salt with crystalline water is chosen as an auxiliary agent is that sodium silicate can replace and fix calcium in tungsten ore, fixing impurity elements such as calcium, iron, and manganese as insoluble substances, and incorporating tungsten into the sodium tungstate component.

[0019] As a preferred solution, the sodium salt is 5-20% of the mass of the low-grade tungsten concentrate, measured as the mass of the sodium salt without water of crystallization. More preferably, the sodium salt is 8-12% of the mass of the low-grade tungsten concentrate. Further increasing the sodium salt dosage will have little effect on improving tungsten decomposition efficiency, but will increase the amount of secondary slag produced during the comprehensive utilization process.

[0020] As a more preferred solution, the roasting conditions are: temperature of 600-1000°C and time of 10-60min. The sodium roasting reaction products of weathered tungsten ore under different temperature conditions are different, and the impurity metal elements are fixed into different products. For example, the solid calcium product of calcite at 600-700°C is Na2Ca2Si3O9, and the solid calcium product at 800°C is Na2Ca2Si3O9 and Na4CaSi3O9. Moreover, with the extension of the roasting reaction time, the WO3 recovery rate tends to first increase and then stabilize. The roasting temperature is further preferably 750-850°C, and the roasting time is further preferably 25-35min, which are more thermodynamically and kinetically optimal. After the preferred roasting conditions, the WO3 recovery rate in tungsten concentrate is ≥90%.

[0021] As a preferred solution, the water immersion conditions are: a water immersion temperature of 20-100°C, a immersion time of 10-60 minutes, a liquid-to-solid ratio of (1-10) mL:1 g, and at least three water immersion cycles. A further preferred solution is: a water immersion temperature of 40-60°C, a immersion time of 20-40 minutes, and a liquid-to-solid ratio of (2-4) mL:1 g. Following this preferred immersion solution, the WO3 concentration in the leachate is ≥15 g / L, meeting ion exchange requirements.

[0022] The functionalized modified polyacrylamide of the present invention is obtained by grafting specific functional groups with targeted adsorption capabilities for tungsten minerals onto the backbone of a conventional flocculant polyacrylamide (PAM). These specific functional groups include carboxyl groups, thiol groups, amino groups, sulfonic acid groups, and hydroxamic acid groups. The modification process can employ known modification methods in the art. For example, PAM can be directly grafted with a compound containing a group reactive with an amide group and also containing specific functional groups with targeted adsorption capabilities for tungsten minerals, such as thioglycolic acid, and the condensation reaction between the carboxyl and amino groups can be used to introduce thiol groups onto the PAM. Alternatively, acrylic acid monomers, acrylate monomers, or acrylamide monomers containing specific functional groups with targeted adsorption capabilities for tungsten minerals can be free-radical copolymerized with acrylamide monomers to introduce specific functional group units, such as acrylic acid or 2-acrylamido-2-methylpropanesulfonic acid, into the PAM. These modification methods are conventional in the art. The synthesis of functionalized modified polyacrylamide is simple, environmentally friendly, and low-cost, and the functional groups can be flexibly selected based on the properties of the raw ore. Functionalized modified polyacrylamide facilitates the synergistic effects of electrostatic forces, hydrogen bonding, or chemical adsorption, further enabling selective aggregation and flocculation through adsorption bridging and net capture and sweeping.

[0023] Compared with the existing technology, the technical solution of the present invention brings the following beneficial technical effects:

[0024] 1. The present invention provides a new idea for the resource recovery of difficult-to-select weathered or semi-weathered tungsten ores. According to the mineral composition characteristics of difficult-to-select weathered or semi-weathered tungsten ores, the key is to separate the easily selectable fine-grained tungsten minerals from the difficult-to-select ultrafine-grained tungsten mud by physical classification of the weathered or semi-weathered tungsten ores, and adopt different technical means to carry out beneficiation according to the characteristics of the two tungsten ores. For the recovery of fine-grained tungsten minerals, metal-based colloidal collectors are used to enhance flotation to obtain high-grade tungsten concentrate, which can be recovered by traditional wet smelting. For the recovery of ultrafine tungsten mud, functionalized modified polyacrylamide is used as a flocculant to achieve efficient selective flocculation and sedimentation of ultrafine tungsten mud to separate other fine mud gangue minerals to obtain low-grade tungsten concentrate. The sodium roasting agent can be introduced to achieve "sodium roasting-water leaching" efficient tungsten extraction, thereby greatly improving the recovery rate of the entire weathered or semi-weathered tungsten ore and obtaining higher-grade tungsten ore.

[0025] 2. The present invention uses a metal-based colloidal collector to enhance the flotation of fine-grained tungsten minerals. Compared with the traditional Petrov heated flotation, the metal-based colloidal collector has better selectivity and lower energy consumption, which greatly weakens the vicious cycle of water glass and can achieve effective recovery of valuable tungsten minerals in fine-grained tungsten ore. The obtained high-grade tungsten concentrate can be directly used as a product and enter the conventional tungsten acid leaching / alkali leaching smelting process.

[0026] 3. The present invention adopts the "selective flocculation-separation" technology based on functional modified polyacrylamide to simultaneously recover valuable tungsten minerals in ultrafine tungsten mud, and to a certain extent pre-enriches this part of tungsten minerals that cannot be effectively recovered by conventional mineral processing methods.

[0027] 4. The present invention uses a new type of hydrated sodium silicate pyrolysis method to roast low-grade tungsten ore recovered from ultrafine tungsten mud to achieve decomposition and conversion, and can effectively fix calcium. The circulating water leaching method can effectively extract the tungsten element and obtain sodium tungstate solution, providing high-quality leachate raw material for the subsequent ion exchange process of tungsten smelting.

[0028] 5. The metal-based colloidal collector selected in the present invention has strong selectivity and can target adsorption and directionally regulate the flotation of tungsten minerals. At the same time, the functionalized modified flocculant selected is simple to synthesize, environmentally friendly, and can flexibly select functional groups according to the properties of the original ore.

[0029] In summary, this technical solution is simple to operate, has low reagent cost, is efficient and clean in new sodium salt roasting, and has strong adaptability in combined beneficiation and synergistic extraction. It truly realizes the effective recovery of all particle sizes of difficult-to-select weathered and semi-weathered tungsten ores, and improves the comprehensive utilization rate of tungsten resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a technical solution diagram of the present invention.

[0031] Figure 2 This is a process flow chart of Comparative Example 1.

[0032] Figure 3 This is a flow chart of the enhanced flotation process for fine-grained tungsten minerals of Example 1.

[0033] Figure 4 This is a process flow chart for the combined beneficiation and extraction of ultrafine tungsten mud in Example 1. DETAILED DESCRIPTION

[0034] The following examples are provided to further illustrate the present invention in detail, but are not intended to limit the scope of protection of the claims of the present invention.

[0035] The weathered or semi-weathered tungsten ore raw materials used in the following examples have undergone conventional tungsten ore pretreatment processes, including crushing, grinding, deironing and desulfurization.

[0036] Comparative Example 1 (Compared with Example 1)

[0037] For Yaogangxian 540 mud mine, Figure 2 The process flow shown is to wash and desludge the raw ore. Using a 200-mesh sieve as the standard, the +0.074mm particle ore accounts for 25%, and the -0.074mm mud ore accounts for 75%.

[0038] For mud ore, a shaking table gravity separation process is used to produce a concentrate with a WO3 grade of 1.01% and a recovery rate of 18.78% (relative to the gravity separation feed) through a coarse and fine process.

[0039] For granular ore, a fatty acid system heated flotation process is adopted, with a flotation pulp concentration of 55%. The pulp pH is adjusted to 10.0 by adding sodium hydroxide, and 2 kg / t of sodium oleate as a collector is added. After aeration and slurry adjustment for 5 minutes, the pH value is 9.5. While vigorously stirring, the pulp is heated to 100°C, and 50 kg / t of water glass is added to strengthen the slurry adjustment. After heat preservation and stirring for 60 minutes, roughing is carried out for 4 minutes. The foam product obtained is blank selected together with a tungsten concentrate containing 7.55% WO3 and a recovery rate of 27.97% (relative to the flotation feed).

[0040] As can be seen from Table 1, the WO3 grade of mud ore is as high as 1.25%, while the WO3 grades of gravity separation concentrate, middlings and tailings are 1.01%, 1.45% and 1.26% respectively. The concentrate grade is the lowest, and the tungsten loss in the tailings exceeds half. It can be said that conventional shaking table gravity separation has no effect on the treatment of mud ore. The overall separation effect is extremely poor, and it is difficult to achieve effective enrichment of valuable tungsten minerals.

[0041] As shown in Table 2, the results of heated flotation of pelletized ore with fatty acids are also unsatisfactory, with the concentrate WO3 grade being only 7.55% and a significant tungsten tailing phenomenon. Furthermore, this method suffers from drawbacks such as a complex heating flotation process, high energy consumption, high reagent consumption, and difficulty in treating return water.

[0042] Therefore, conventional mineral processing methods such as gravity separation and flotation are not suitable for weathered and semi-weathered tungsten ores, and the comprehensive recovery rate of WO3 is less than 30%, resulting in serious waste of tungsten resources.

[0043] Table 1 Comparative Example 1 Mud Ore Shaking Table Gravity Separation Test Results

[0044]

[0045] Table 2 Comparative Example 1 Granular Ore Flotation Test Results

[0046]

[0047] Example 1

[0048] 0.125 mol of lead nitrate was added to 1 L of 1.0 mol / L benzohydroxamic acid solution under stirring, and the mixture was reacted for 3 minutes to obtain the metal-based colloidal collector.

[0049] 0.1 mol of a hydroxylamine base solution was added to 1 L of a 0.1 mol / L polyacrylamide aqueous solution under stirring, and the reaction was carried out at 60°C for 4 hours and then at 85°C for 3 hours to obtain the hydroxamic acid-modified polyacrylamide. The hydroxylamine hydrochloride solution was prepared by mixing hydroxylamine hydrochloride and deionized water in a certain ratio to form a 40 wt% hydroxylamine hydrochloride solution, and the pH was adjusted to 13.5 with 20 wt% sodium hydroxide solution to obtain the hydroxylamine base solution.

[0050] The Yaogangxian 540 mud ore was treated by this process and finely classified by hydrocyclone to obtain +5μm fine-grained tungsten minerals and -5μm ultrafine-grained tungsten fine mud. The two major components accounted for 10% and 90% respectively. Figure 3 The process flow is shown.

[0051] For fine-grained tungsten minerals, the slurry pH was adjusted to 9.7 by adding sodium carbonate, 100 g / t of Al-Na2SiO3 inhibitor was added, the slurry was stirred for 3 minutes, 1000 g / t of Pb-BHA metal-based colloidal collector was added, the slurry was aerated and stirred for 5 minutes until the pH was 8.5, 40 g / t of frother 2# oil was added, and roughing was carried out for 4 minutes. 2# oil was added at 20 g / t and 10 g / t respectively in two scavenging processes, and the scavenging time was 3 minutes; inhibitors were added at 50 g / t, 25 g / t and 12.5 g / t respectively in three concentrating processes, and finally a high-grade tungsten concentrate WO321.4% was obtained with a recovery rate of 58.7% (relative to the feed ore). The wet acid leaching process was further adopted for effective recovery. The concentrate product was added into a mixture of sulfuric acid and phosphoric acid in a mass ratio of 1:2 and stirred for leaching. The stirring intensity was 1500r / min, the leaching temperature was 80°C, and the leaching time was 4h. Finally, the WO3 leaching rate in the phosphotungstic acid leaching solution reached 99.57%. Subsequently, tungsten was separated by cooling and crystallization, and the mother liquor was recycled for leaching.

[0052] For ultrafine tungsten mud, the slurry concentration is controlled at 40%, the stirring speed is 2500r / min, 200g / t sodium hexametaphosphate and 300g / t water glass are added to fully disperse the slurry, sodium carbonate is added to adjust the slurry pH to 8.0, 50g / t hydroxamic acid-modified polyacrylamide is added, and selective flocculation is allowed to settle for 2 hours. The separated sediment is the low-grade tungsten concentrate. Tungsten is further extracted using sodium roasting and water leaching. Sodium silicate / hydrated sodium silicate salt is added at a ratio of 9%, roasted at 800℃ for 30 minutes, removed, cooled, crushed, and ground to -0.074mm. The liquid-to-solid ratio is controlled at 3:1, and water leaching is performed at 50℃ for 30 minutes, with three cycles of water leaching.

[0053] As shown in Table 3, the new method for processing fine-grained tungsten ore from the Yaogangxian 540 mud mine, using a metal-based colloidal collector, demonstrates excellent selectivity and capture capacity for directly flotation-capable particles. The overall "low-water-glass" flotation process achieves a total Al-SS concentration of no more than 200 g / t. After a roughing, refining, and scavenging process, a high-grade tungsten concentrate with a WO3 content of 21.4% and a recovery of 58.7% is obtained. This method exhibits excellent flotation performance, and the high-grade tungsten concentrate can be directly sold as a product for use in conventional tungsten hydrometallurgical processes.

[0054] As can be seen from Table 5, for ultrafine tungsten mud, a certain degree of enrichment can be achieved through selective flocculation-sedimentation separation, and a low-grade tungsten concentrate with a WO3 grade of 2.14% is obtained, with a recovery rate of 69.5%, which provides raw materials for the subsequent pyro-roasting-water leaching process.

[0055] As shown in Table 6, ultrafine tungsten sludge undergoes synergistic extraction through beneficiation and smelting, and is roasted using sodium silicate nonahydrate as an additive, resulting in a leachate with a WO3 concentration of 15.94 g / L, meeting the requirements for subsequent ion exchange processes. The overall recovery rate for beneficiation and smelting reaches 64.5%. Compared to conventional beneficiation methods, "selective flocculation-sedimentation separation" allows for the pre-enrichment of valuable minerals in ultrafine tungsten sludge. The novel sodium silicate hydrate roasting-water leaching process effectively decomposes, transforms, and efficiently extracts low-grade tungsten concentrate.

[0056] Overall, this method uses different technical ideas to effectively recover valuable tungsten minerals from the two major components of weathered tungsten ore, truly realizing the comprehensive utilization of tungsten resources in weathered and semi-weathered tungsten ore.

[0057] Table 3 Closed-circuit test results of fine-grained tungsten ore flotation in Example 1

[0058]

[0059] Table 4 Example 1 High-grade tungsten concentrate sulfuric acid and phosphoric acid synergistic leaching test results

[0060]

[0061] Table 5 Results of the selective flocculation-sedimentation test of ultrafine tungsten mud in Example 1

[0062]

[0063] Table 6 Example 1 Ultrafine Tungsten Sludge Beneficiation and Smelting Cooperative Test Results

[0064]

[0065] Comparative Example 2 (Compared with Example 2)

[0066] For the weathered tungsten ore of Vision Tungsten Industry, after further crushing and roller mixing in the laboratory, centrifugal gravity separation tests were carried out on ore samples with different grinding fineness (-200 mesh particle size ratio). The leaching water volume was set at 4L / min and the drum frequency was set at 30Hz. A separation operation was carried out to obtain concentrate and tailings products.

[0067] The WO3 grade of Yuanjing weathered tungsten ore is approximately 1.1%. As shown in Table 7, the centrifugal concentrate yield generally changes little with increasing feed fineness. The concentrate WO3 grade shows no significant regularity between 0.58% and 0.65%, remaining at a relatively low level. Compared to the centrifugal tailings product, the concentrate grade is significantly lower, with a recovery rate of only approximately 40%. Conventional centrifugal gravity separation alone is difficult to recover valuable tungsten minerals from this weathered tungsten ore.

[0068] Table 7 Comparative Example 2 Centrifugal Gravity Separation Test Results

[0069]

[0070]

[0071] Example 2

[0072] 0.125 mol of lead nitrate was added to 1 L of 1.0 mol / L benzohydroxamic acid solution under stirring, and the mixture was reacted for 3 minutes to obtain the metal-based colloidal collector.

[0073] This process was used to treat the weathered tungsten ore from Yuanjing Tungsten Industry. The crushing and grinding procedures were consistent with those in Comparative Example 2, resulting in a grinding fineness of 80%. Fine classification using a hydrocyclone yielded an overflow product yield of 85% and a grit product yield of 15%. The overflow product, representing ultrafine tungsten sludge, was fine-grained tungsten mineral. Metal-based colloidal collectors were used to enhance the flotation of fine-grained tungsten minerals. The corresponding roughing reagent system was as follows: 400 g / t of Na₂CO₃ and 200 g / t of Al-Na₂SiO₃ were added sequentially, with slurry mixing and stirring for 4 minutes. 1200 g / t of Pb-BHA was added, and after aeration and stirring for 5 minutes until the pH stabilized at 8.7, 30 g / t of BK₂O₅ was added, and roughing continued for 4 minutes. The roughing foam product was then subjected to three separate cleaning operations, each lasting 3 minutes, with inhibitors added at 100 g / t, 50 g / t, and 25 g / t, respectively. The roughing tailings were subjected to two separate scavenging operations, with 15 g / t and 7.5 g / t of BK₂O₅ added, respectively, for 3 minutes. The middlings were returned sequentially. The final closed-circuit flotation test results showed a tungsten concentrate with a WO₃ grade of 24.5% and a recovery of 55.3%. For ultrafine tungsten sludge, the same process flow as in Example 1 was employed, differing only in that 75 g / t of hydroxamic acid-modified polyacrylamide (prepared as described in Example 1) was added for selective flocculation. The resulting leachate from the combined beneficiation and smelting process had a WO3 concentration of 15.74 g / L, and a comprehensive recovery rate of 64.5%.

[0074] Table 8 Closed-circuit test results of fine-grained tungsten ore flotation in Example 1

[0075]

[0076] Table 9 Example 2 Ultrafine Tungsten Sludge Beneficiation and Smelting Cooperative Test Results

[0077]

[0078]

[0079] *Represents the concentration of WO3 in the leachate in g·L -1 , 64.5% is the comprehensive recovery rate of mineral processing.

Claims

1. A combined beneficiation and smelting method for weathered tungsten ore, characterized by: The following steps are involved: 1) Classify the weathered or semi-weathered tungsten ore through cyclone classification to obtain fine-grained tungsten ore and ultrafine-grained tungsten mud; 2) flotating the fine-grained tungsten ore using a reagent system comprising a metal-based colloidal collector to obtain a high-grade tungsten concentrate, which enters a hydrometallurgical smelting process; 3) The ultrafine tungsten mud is selectively flocculated and settled by a functionalized modified polyacrylamide flocculant to obtain a low-grade tungsten concentrate, and the low-grade tungsten concentrate is subjected to a sodium roasting-water leaching process to obtain a sodium tungstate solution; the functionalized modified polyacrylamide flocculant is a polyacrylamide having at least one functional group selected from the group consisting of carboxyl, thiol, amino, sulfonic acid, and hydroxamic acid grafted onto the main chain.

2. The method for combined beneficiation and smelting of weathered tungsten ore according to claim 1, characterized in that: The particle size range of the cyclone classification is 5 to 10 μm, the particle size of the obtained fine-grained tungsten mineral satisfies the mass content of the +5 μm particle size ≥ 50%, and WO3 ≥ 0.60 wt.%, and the particle size of the obtained ultrafine-grained tungsten mud satisfies the mass content of the -5 μm particle size ≥ 50%, and WO3 ≥ 0.80 wt.%.

3. The method for combined beneficiation and smelting of weathered tungsten ore according to claim 1, characterized in that: The metal-based colloidal collector is formed by the coordination assembly of a hydroxamic acid organic ligand and a divalent or higher metal ion; The divalent or higher metal ions include Pb 2+ , Ca 2+ 、Cu 2+ Mg 2+ 、Zn 2+ 、Mn 2+ 、Ni 2+ 、Fe 2+ 、Fe 3+ or La 3+ At least one of the following; The hydroxamic acid organic ligand includes at least one of benzohydroxamic acid, salicylic hydroxamic acid, octyl hydroxamic acid, naphthyl hydroxamic acid and benzenesulfonyl hydroxamic acid; The coordination molar ratio of the divalent or higher metal ion to the hydroxamic acid ligand is 1:(1-16).

4. The method for combined dressing and smelting of weathered tungsten ore according to claim 1 or 3, characterized in that: The flotation comprises one roughing separation, at least three cleaning separations and at least two scavenging separations; The reagent system for the roughing is as follows: sodium carbonate is added as an adjuster to adjust the pH to 8.5-10.5, the dosage of salinized water glass inhibitor is 100-200 g / t, the dosage of metal-based colloidal collector is 1000-1500 g / t, and the dosage of 2# oil foaming agent is 40-60 g / t; The medicine system for selection and sweeping follows the principle of halving in sequence.

5. The method for combined beneficiation and smelting of weathered tungsten ore according to claim 1, characterized in that: The process of selective flocculation and sedimentation of ultrafine tungsten mud is as follows: the ultrafine tungsten mud is first dispersed by adding a dispersant, then a functional modified polyacrylamide flocculant is added to perform shear flocculation and hydrophobic agglomeration under high-speed stirring, and finally sedimentation and separation.

6. The method for combined beneficiation and smelting of weathered tungsten ore according to claim 5, characterized in that: The dispersant is at least one of water glass, sodium hexametaphosphate, sodium tripolyphosphate, sodium pyrophosphate, sodium lauryl sulfate, polyethylene glycol fatty acid ester, methyl amyl alcohol, guar gum and carboxymethyl cellulose; The amount of the dispersant is 500 to 2000 g / t; The dosage of the functional modified polyacrylamide flocculant is 10-100 g / t.

7. The method for combined dressing and smelting of weathered tungsten ore according to claim 1, characterized in that: The sodium roasting-water leaching process is as follows: sodium salt and low-grade tungsten concentrate are mixed, roasted, crushed, ground and water-leached in sequence to obtain a sodium tungstate solution.

8. The method for combined dressing and smelting of weathered tungsten ore according to claim 7, characterized in that: The sodium salt includes at least one of Na2SiO3, Na2SiO3·5H2O and Na2SiO3·9H2O; The mass of the sodium salt is 5-20% of the mass of the low-grade tungsten concentrate, and the sodium salt is measured based on the mass of the sodium salt without crystal water.

9. The method for combined dressing and smelting of weathered tungsten ore according to claim 7, characterized in that: The calcination conditions are: temperature of 600-1000° C. and time of 10-60 minutes.

10. The method for combined dressing and smelting of weathered tungsten ore according to claim 7, characterized in that: The water immersion conditions are as follows: the water immersion temperature is 20-100° C., the time is 10-60 min, the liquid-to-solid ratio is (1-10) mL:1 g, and the water immersion cycle times are at least three times.

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