Dressing and smelting combined method for treating weathered tungsten

Abstract

The invention discloses a dressing and smelting combined treatment method for weathered tungsten ore, and belongs to the technical field of mineral processing. The method comprises the following steps: carrying out rotational flow classification on weathered or semi-weathered tungsten ore to obtain fine-fraction tungsten ore and superfine-fraction tungsten fine silt; the fine-fraction tungsten minerals are subjected to flotation through a reagent system containing a metal-based colloid collecting agent, high-grade tungsten concentrate is obtained, and the high-grade tungsten concentrate enters a wet smelting process; the method comprises the following steps: selectively flocculating and settling superfine tungsten fine silt through a functional modified polyacrylamide flocculating agent to obtain low-grade tungsten concentrate, and carrying out a sodium salt roasting-water leaching process on the low-grade tungsten concentrate to obtain a sodium tungstate solution. According to the method, the tungsten element in the weathered or semi-weathered tungsten ore can be deeply enriched and recycled, clean and efficient utilization and sustainable development of tungsten ore resources are promoted, and remarkable economic benefits are achieved.

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 ore dressing and metallurgy. Background Art

[0002] At present, more than 20 kinds 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 considered to be produced by hydrothermal or surface alteration of primary tungsten minerals, rather than by atmospheric weathering. Typical semi-weathered tungsten minerals include hydrotungsten, calcium tungsten and wax tungsten; weathered tungsten ore refers to a type of tungsten ore formed by the reorganization of mineral composition and chemical composition of the surface part of primary tungsten ore under the action of atmosphere, water, organisms, etc. Compared with primary tungsten ore, the mineral composition and properties of weathered tungsten ore and semi-weathered tungsten ore have changed significantly, and the tungsten content of tungsten ore has increased after weathering. However, due to weathering, this type of ore is easily over-grinded during the crushing and grinding stage of mineral processing, presenting a fine particle distribution state, with a significant increase in specific surface area. It is inevitable that the number of ions in the slurry will increase, and the probability of collision and adhesion with bubbles will decrease. The separation efficiency of conventional flotation and gravity separation processes will be greatly reduced. The presence of weathered tungsten ore seriously affects the enrichment of tungsten in the processing process, resulting in a decrease in tungsten recovery rate.

[0003] With the continuous depletion of easily selectable tungsten resources, the recycling of weathered tungsten ore and semi-weathered tungsten ore is imminent. Investigations have found that the grade of weathered tungsten ore and semi-weathered tungsten ore is generally higher than that of primary tungsten ore. In order 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 very difficult to select and cannot meet the minimum technical index requirements for resource development and utilization. The typical characteristics of valuable tungsten minerals in weathered tungsten ores are small mass and large specific surface area, which determines the difficulty of their efficient separation. 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 prior art, 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 view of the difficulty of extremely fine embedded particle size of weathered tungsten ores (most of which are distributed below 10μm) and difficult to recover by flotation, a treatment method of high-concentration slurry shear flocculation stirring and high-speed jet pre-mineralization is designed to pretreat fine weathered tungsten ores before flotation, which 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 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 exhausted and the current smelting technology is difficult to process weathered and semi-weathered tungsten ores, the purpose of the present invention is to provide a smelting and combined processing method for weathered tungsten ore. The method finely classifies the semi-weathered or weathered tungsten ore and adopts different smelting methods according to the 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 treatment method for beneficiation and smelting of weathered tungsten ore, which comprises the following steps:

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

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

[0009] 3) The ultrafine tungsten mud is selectively flocculated and settled by a functional 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 functional modified polyacrylamide flocculant is a polyacrylamide with at least one functional group selected from carboxyl, thiol, amino, sulfonic acid, and hydroxamic acid grafted onto the main chain.

[0010] The combined treatment method for beneficiation of weathered tungsten ore provided by the present invention mainly comprises the following steps of finely classifying weathered or semi-weathered tungsten ores, and flotation separation of fine-grained tungsten minerals and ultrafine-grained tungsten mud obtained by classification is respectively carried out using metal-based colloidal collectors 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] According to the characteristics of difficult-to-select weathered or semi-weathered tungsten ore, such as easy over-grinding, fine particle size, small mass, and large specific surface area, the fine-grained tungsten ore that can be directly floated is first finely classified by hydrocyclones to separate the fine-grained tungsten ore that can be directly floated from the ultra-fine tungsten mud that is difficult to directly recover by conventional beneficiation methods. The key to the recovery of fine-grained tungsten ore is to use metal-based colloidal collectors to enhance flotation. The oxygen atoms on the surface of tungsten ore can be targetedly adsorbed by metal ions to achieve directional control of its surface roughness, enhance the difference in hydrophilicity and hydrophobicity of the mineral surface, and achieve efficient recovery. This part of high-grade tungsten concentrate can be recovered by traditional hydrometallurgy. The key to recovering ultrafine tungsten mud that is difficult to extract directly is to use functional modified polyacrylamide as a flocculant. By grafting specific functional groups that have a targeted effect 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 by "sodium roasting-water leaching" by introducing sodium roasting reagents.

[0012] As a preferred solution, the particle size range of the cyclone classification is 5-10 μm, the particle size of the obtained fine-grained tungsten mineral satisfies the mass content of the +5 μm particle size ≥50%, and WO3 ≥0.60wt.%, and the particle size of the obtained ultra-fine-grained tungsten fine mud satisfies the mass content of the -5 μm particle size ≥50%, and WO3 ≥0.80wt.%. The cyclone classification is mainly to separate the fine-grained tungsten minerals that can be directly recovered by flotation, and flotation recovery can be carried out to obtain a high-grade tungsten concentrate, while the remaining ultra-fine-grained tungsten fine mud that is difficult to effectively recover by conventional mineral processing methods such as gravity separation and flotation is enriched by means of flocculation and precipitation, and the main purpose is to improve the comprehensive recovery rate of tungsten. It is further preferred that the feed concentration of the cyclone classification is 10-20wt.%, and the appropriate feed concentration is conducive to stable production and efficient fine classification of weathered or semi-weathered tungsten ores.

[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 them. As a more preferred solution, 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 more preferred solution, the coordination molar ratio of the divalent or higher metal ion to the hydroxamic acid ligand is 1:(1-16). The metal-based colloidal collector is a metal-organic complex with a special three-dimensional structure formed by coordination assembly between metal ions and hydroxamic acid organic ligands. Its LUMO orbit is mainly contributed by the high-valent central metal ion, while the HOMO orbit of the weathered tungsten mineral surface is mainly contributed by the O-2p orbit at the top of the valence band. Conventional tungsten ore flotation collectors, such as fatty acids, mainly use their carboxylic acid groups to act on the active sites of metal ions on the surface of tungsten minerals, while metal-organic complexes can be targetedly adsorbed on oxygen atoms on the surface of tungsten minerals through their metal bases to achieve directional regulation of its surface roughness, thereby enhancing the difference in hydrophilicity and hydrophobicity of the mineral surface and strengthening flotation recovery.

[0014] As a preferred solution, the flotation includes one roughing, at least three cleaning and at least two scavenging. As a more preferred solution, the reagent system of the roughing is: sodium carbonate adjuster to adjust pH=8.5-10.5, salted water glass inhibitor is 100-200g / t, metal-based colloidal collector is 1000-1500g / t, 2# oil frother is 40-60g / t; the reagent system of cleaning and scavenging follows the principle of halving in sequence. Salted water glass is for example Al-Na2SiO3.

[0015] As a preferred solution, the process of selective flocculation and sedimentation of ultrafine tungsten mud is: ultrafine tungsten mud is first dispersed by adding a dispersant, and then a functional modified polyacrylamide flocculant is added to perform shear flocculation and hydrophobic agglomeration under high-speed stirring, and finally sedimentation and separation. It is further preferred that the pulp concentration is controlled within the range of 30 to 60 wt.% during the flocculation and sedimentation process. As a more preferred solution, the dispersant is at least one of water glass, sodium hexametaphosphate, sodium tripolyphosphate, sodium pyrophosphate, sodium dodecyl sulfate, fatty acid polyethylene glycol esters, methyl amyl alcohol, gur gum and carboxymethyl cellulose. As a more preferred solution, the amount of the dispersant is 500 to 2000 g / t.

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

[0017] As a preferred solution, the sodium roasting-water leaching process is: sodium salt and low-grade tungsten concentrate are mixed, roasted, crushed, ground and water-leached in sequence to obtain a sodium tungstate solution. The sodium salt is evenly mixed with the low-grade tungsten concentrate as an auxiliary agent, which is conducive to improving the efficiency of high-temperature solid-phase reaction. The presence of sodium salt under high temperature conditions can promote the decomposition and transformation of tungsten-containing minerals, so that the difficult-to-leach tungsten ore is converted into water-soluble sodium tungstate. The roasted product is then crushed and ground to an appropriate particle size (-0.074mm), and the circulating water leaching method is used for efficient extraction. The leaching residue is filtered to remove the leaching solution, 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, and the most preferred is Na2SiO3·9H2O. Sodium silicate with crystal water is used, which removes crystal water at high temperature and quickly forms nano-sized sodium silicate coated on the surface of the mineral, which has higher reactivity. Sodium silicate or sodium salt with crystal water is selected as an auxiliary agent, mainly because sodium silicate can achieve calcium replacement and fixation in tungsten ore, impurity elements such as calcium / iron / manganese are fixed as insoluble substances, and tungsten element enters the sodium tungstate component.

[0019] As a more preferred solution, the mass of the sodium salt is 5-20% of the mass of the low-grade tungsten concentrate, and the sodium salt is measured by the mass of the sodium salt without crystal water. The mass of the sodium salt is further preferably 8-12% of the mass of the low-grade tungsten concentrate. On this basis, if the amount of sodium salt is further increased, the effect on the improvement of tungsten decomposition efficiency is weak, and the amount of secondary slag in the comprehensive utilization process will increase.

[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 are different under different temperature conditions, 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 roasting reaction time, the WO3 recovery rate tends to increase first and then stabilize. The roasting temperature is further preferably 750-850°C, and the roasting time is further preferably 25-35min, which is more thermodynamically and kinetically optimal. After the preferred roasting conditions, the WO3 recovery rate in tungsten concentrate is ≥90%.

[0021] As a more preferred solution, the conditions for water immersion are: water immersion temperature is 20-100°C, time is 10-60min, liquid-solid ratio is (1-10)mL:1g, and water immersion cycles are at least three times. A further preferred solution is: water immersion temperature is 40-60°C, water immersion time is 20-40min, and liquid-solid ratio is (2-4)mL:1g. After the preferred water immersion solution, the WO3 concentration in the leaching solution is ≥15g / L, which can meet the requirements of ion exchange.

[0022] The functionalized modified polyacrylamide of the present invention is obtained by grafting a characteristic functional group having a targeted adsorption function for tungsten minerals onto the main chain of conventional flocculant polyacrylamide PAM. The characteristic functional groups include carboxyl, thiol, amino, sulfonic acid, hydroxamic acid, etc. The modification process can adopt the modification methods known in the prior art, such as directly grafting PAM with a compound having a group that can react with an amide group and at the same time containing a characteristic functional group having a targeted adsorption function for tungsten minerals, such as thioglycolic acid, and introducing a thiol group on PAM by using the condensation reaction of carboxyl and amino groups. For another example, acrylic acid monomers, acrylic acid ester monomers or acrylamide monomers containing a characteristic functional group having a targeted adsorption function for tungsten minerals can be used for free radical copolymerization with acrylamide monomers, so that units containing characteristic functional groups can be introduced into PAM, such as acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid, etc. These modification methods are all conventional modification methods in the prior art. The synthesis of functionalized modified polyacrylamide is simple, environmentally friendly, low-cost, and can flexibly select characteristic functional groups according to the properties of the original ore. Functionalized modified polyacrylamide is conducive to the synergistic effect of electrostatic force, hydrogen bond or chemical adsorption, and further achieves selective aggregation and flocculation through adsorption bridging and net capture and sweeping.

[0023] Compared with the prior art, the technical solution of the present invention has 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 strengthen flotation, and high-grade tungsten concentrate can be obtained for recovery through 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 a higher grade tungsten ore.

[0025] 2. The present invention uses metal-based colloidal collectors to enhance the flotation of fine-grained tungsten minerals. Compared with the traditional Petrov heated flotation, the metal-based colloidal collectors have 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 ores. 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 the tungsten minerals that cannot be effectively recovered by conventional mineral processing methods.

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

[0028] 5. The metal-based colloidal collector selected by 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, the new sodium salt roasting is efficient and clean, and the combined synergistic extraction of beneficiation and smelting has strong adaptability. 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 the 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 extraction of ultrafine tungsten mud from the beneficiation process of 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 been subjected to conventional tungsten ore pretreatment processes, including crushing, grinding, iron removal 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 desludging the raw ore. Using a 200-mesh sieve as the standard, 25% of the ore particles with a diameter of +0.074 mm and 75% of the ore mud with a diameter of -0.074 mm are screened out.

[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).

[0039] For the particle ore, the fatty acid system heating flotation process is adopted, the flotation pulp concentration is 55%, the pulp pH is adjusted to 10.0 by adding sodium hydroxide, 2kg / t of sodium oleate collector is added, the pH is 9.5 after aeration and slurry stirring for 5 minutes, the pulp is heated to 100°C while stirring vigorously, 50kg / 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, and the obtained foam product 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 of tailings exceeds half. It can be said that conventional shaking table gravity separation has no effect on the treatment of mud ore, and the overall separation effect is extremely poor, making it difficult to achieve effective enrichment of valuable tungsten minerals.

[0041] As can be seen from Table 2, the effect of fatty acid heating flotation of pellet ore is not ideal, the concentrate WO3 grade is only 7.55%, and the tungsten tailing phenomenon is serious. At the same time, this method also has the disadvantages of complex heating and concentration process, high energy consumption, large amount of reagents and difficult return water treatment.

[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 reacted for 3 minutes to obtain the metal-based colloidal collector.

[0049] Under stirring conditions, 0.1 mol of hydroxylamine alkaline solution was added to 1 L of 0.1 mol / L polyacrylamide hydrosol, and the hydroxamic acid was oxidized for 4 h at 60° C. and hydrolyzed for 3 h at 85° C. to obtain the hydroxamic acid modified polyacrylamide. Hydroxylamine hydrochloride and deionized water were prepared in a certain proportion to form a 40 wt % hydroxylamine hydrochloride solution, and the pH was adjusted to 13.5 with a 20 wt % sodium hydroxide solution to obtain the hydroxylamine alkaline solution.

[0050] The Yaogangxian 540 mud ore is treated by this process and finely classified by a hydrocyclone to obtain +5μm fine-grained tungsten minerals and -5μm ultra-fine-grained tungsten fine mud, with the two major components accounting 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 pH was 8.5 after aeration and stirring for 5 minutes, 40 g / t of frother 2# oil was added, and roughing was carried out for 4 minutes. 2# oil was added with 20 g / t and 10 g / t of 2# oil respectively for two scavenging processes, and the scavenging time was 3 minutes; inhibitors were added with 50 g / t, 25 g / t and 12.5 g / t respectively for three concentrating processes, and finally a high-grade tungsten concentrate WO321.4% was obtained, and the recovery rate was 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 ultra-fine tungsten mud, the pulp 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 pulp, sodium carbonate is added to adjust the pulp pH to 8.0, 50g / t hydroxamic acid modified polyacrylamide is added, and selective flocculation is allowed to settle for 2h. The separated sediment is the low-grade tungsten concentrate. Further sodium roasting-water leaching is used to extract tungsten, sodium silicate / hydrated sodium silicate salt ratio is added at 9%, roasted at 800℃ for 30min, the product is taken out and cooled, crushed and ground to -0.074mm, the liquid-solid ratio is controlled to 3:1, and water soaked at 50℃ for 30min, and the water soaking is cycled three times.

[0053] As can be seen from Table 3, the new method is used to treat the fine-grained tungsten ore produced by fine classification of Yaogangxian 540 mud mine. The metal-based colloidal collector shows good selectivity and collection ability for the particle ore that can be directly floated. The overall flotation process is "no / low water glass". The total amount of Al-SS does not exceed 200g / t. After one roughing, three fines and two sweeps, high-grade tungsten concentrate WO321.4% is obtained, and the recovery rate is 58.7%. The flotation index of this method is good, and the high-grade tungsten concentrate can be directly sold as a product and enter the conventional tungsten hydrometallurgical process.

[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% and a recovery rate of 69.5% can be obtained, thereby providing raw materials for the subsequent pyro-roasting-water leaching process.

[0055] As can be seen from Table 6, after the ultra-fine tungsten fine mud was subjected to the combined extraction of dressing and smelting, the WO3 concentration in the leachate was finally obtained by roasting with sodium silicate nine hydrate as an auxiliary agent, reaching 15.94g / L, which met the standard requirements of the subsequent ion exchange process, and the comprehensive recovery rate of dressing and smelting reached 64.5%. Compared with conventional mineral processing methods, "selective flocculation-sedimentation separation" can realize the pre-enrichment of valuable minerals in ultra-fine tungsten fine mud, and the roasting-water leaching process of the new sodium silicate hydrate can effectively decompose, transform and efficiently extract low-grade tungsten concentrate.

[0056] On the whole, 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 flotation of fine-grained tungsten ore 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 Example 1 Ultrafine Tungsten Sludge Selective Flocculation-Sedimentation Test Results

[0062]

[0063] Table 6 Example 1 Ultrafine Tungsten Fine Mud Smelting Cooperative Test Results

[0064]

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

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

[0067] The WO3 grade of the prospective weathered tungsten ore is about 1.1%. As can be seen from Table 7, as the feed fineness becomes finer, the overall centrifugal concentrate yield does not change much. The concentrate WO3 grade has no obvious regular changes between 0.58 and 0.65%, all at a relatively low level. Compared with the centrifugal tailings product, the concentrate grade is significantly lower, and the recovery rate is only about 40%. It is difficult to recover the valuable tungsten minerals in the weathered tungsten ore by conventional centrifugal gravity separation alone.

[0068] Table 7 Comparative Example 2 Centrifugal Gravity 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 reacted for 3 minutes to obtain the metal-based colloidal collector.

[0073] The process was used to treat the weathered tungsten ore of Yuanjing Tungsten Industry, and the crushing and grinding procedures were consistent with those in Comparative Example 2, with a grinding fineness of 80%. The hydrocyclone was used for fine classification, with an overflow product yield of 85% and a sand settling product yield of 15%, the former being ultrafine tungsten fine mud and the latter being fine-grained tungsten minerals. Metal-based colloidal collectors were used to enhance the flotation of fine-grained tungsten minerals. The corresponding roughing reagent system was as follows: Na2CO3 400g / t, inhibitor Al-Na2SiO3 200g / t were added in sequence, the slurry mixing time was 4min, Pb-BHA 1200g / t was added, the pH was stabilized to 8.7 after aeration and slurry mixing for 5min, frother BK205 30g / t was added, and roughing was performed for 4min; the roughing foam product was subjected to three cleaning operations, the cleaning time was 3min, and inhibitors of 100g / t, 50g / t and 25g / t were added for the three cleaning operations respectively; the roughing tailings were subjected to two scavenging operations, frother BK205 15g / t and 7.5g / t were added respectively, and the scavenging time was 3min; the middlings were returned in sequence. The final flotation closed-circuit test results were that the tungsten concentrate WO3 grade was 24.5% and the recovery rate was 55.3%. For ultrafine tungsten fine mud, the same process as in Example 1 was adopted, the only difference being that the amount of hydroxamic acid modified polyacrylamide (preparation method see Example 1) added for selective flocculation was 75 g / t. The WO3 concentration in the leaching solution obtained by the final beneficiation and smelting combined process was 15.74 g / L, and the comprehensive recovery rate of beneficiation and smelting reached 64.5%.

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

[0075]

[0076] Table 9 Example 2 Ultrafine Tungsten Fine Mud Smelting Cooperative Test Results

[0077]

[0078]

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

Claims

1. A combined treatment method for beneficiation and smelting of weathered tungsten ore, characterized in that: The following steps are involved: 1) Classify the weathered or semi-weathered tungsten ore by cyclone to obtain fine-grained tungsten ore and ultra-fine-grained tungsten mud; 2) flotating the fine-grained tungsten ore using a reagent system containing a metal-based colloidal collector to obtain a high-grade tungsten concentrate, which enters a hydrometallurgical process; 3) The ultrafine tungsten mud is selectively flocculated and settled by a functional 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 functional modified polyacrylamide flocculant is a polyacrylamide with at least one functional group selected from carboxyl, thiol, amino, sulfonic acid, and hydroxamic acid grafted onto the main chain.

2. The method for combined treatment 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 fine mud satisfies the mass content of the -5 μm particle size ≥ 50%, and WO3 ≥ 0.80 wt.%.

3. The method for combined treatment of weathered tungsten ore according to claim 1, characterized in that: The metal-based colloidal collector is formed by the coordination and assembly of hydroxamic acid organic ligands and divalent or higher metal ions; 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. A combined treatment method for beneficiation and smelting of weathered tungsten ore according to claim 1 or 3, characterized in that: The flotation comprises one roughing selection, at least three cleaning selections and at least two scavenging selections; The reagent system of the rough selection is: adding sodium carbonate as an adjusting agent to adjust the pH to 8.5-10.5, the dosage of salinized water glass inhibitor is 100-200 g / t, the metal-based colloidal collector is 1000-1500 g / t, and the 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 dressing and smelting of weathered tungsten ore according to claim 1, characterized in that: The process of selective flocculation and sedimentation of ultrafine tungsten sludge is as follows: the ultrafine tungsten sludge is first dispersed by adding a dispersant, and then a functional modified polyacrylamide flocculant is added to perform shear flocculation and hydrophobic agglomeration under high-speed stirring, and finally separated by sedimentation.

6. The method for combined dressing 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 dosage of the dispersant is 500-2000 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 by 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 min.

10. The method for combined dressing and smelting of weathered tungsten ore according to claim 7, characterized in that: The water immersion conditions are: 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.

Images