Method for recovering ultralow-grade tungsten from molybdenum tailings
By combining heavy medium separation, classification and flotation, and using benzohydroxyxamic acid and diethyltoluene diamine as collectors, the problem of ineffective recovery of low-grade tungsten resources in molybdenum tailings was solved, and efficient recovery and grade improvement of tungsten were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-06
- Publication Date
- 2026-04-10
AI Technical Summary
In existing technologies, low-grade tungsten resources in molybdenum tailings are not effectively recovered, resulting in resource waste.
A method combining heavy media separation, classification, coarse-grained tungsten flotation, and conventional flotation was adopted. Through four stages of heavy media separation of concentrate and flash flotation, combined with benzohydroxyxamic acid and diethyltoluene diamine as collectors, the tungsten recovery rate was improved.
This method enables efficient recovery of tungsten from molybdenum tailings, improves the grade of tungsten concentrate, reduces production costs, and increases the tungsten recovery rate.
Smart Images
Figure CN121820040A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of ore dressing, and particularly relates to a method for recovering ultra-low-grade tungsten from molybdenum tailings. BACKGROUND
[0002] Metal tungsten has the characteristics of high hardness, high melting point and air corrosion resistance at room temperature, and is widely used in steel iron, military industry, aerospace, electronics, electrical appliances and chemical industry. Tungsten is a non-renewable strategic mineral resource, although China is rich in tungsten resources, but has the characteristics of "rich ore, more poor ore, more associated ore, and less single ore", and at the same time, with the development of social economy, the demand for tungsten is increasing, and the resource reserves are rapidly decreasing. It is inevitable to recover low-grade tungsten resources.
[0003] A large amount of molybdenum tailings will be produced in the molybdenum flotation process, and the molybdenum tailings also contain low-grade tungsten. However, due to the low grade and complex composition, the molybdenum tailings are usually sent to the tailings pond for storage in the prior art, so that the tungsten resources with economic value cannot be recovered, resulting in waste of tungsten resources.
[0004] Therefore, it is urgent to develop a method for efficiently and lowly recovering tungsten from molybdenum tailings to realize the recovery of tungsten resources. SUMMARY
[0005] The present application provides a method for recovering ultra-low-grade tungsten from molybdenum tailings to solve the problems mentioned in the background.
[0006] The present application provides a method for recovering ultra-low-grade tungsten from molybdenum tailings, which comprises the following steps: (1) The molybdenum tailings are subjected to heavy medium separation to obtain a concentrate 1 and a tailings 1; (2) The concentrate 1 is subjected to classification to obtain an oversize and an undersize; (3) The oversize is subjected to coarse particle grade tungsten flotation to obtain a concentrate 2 and a tailings 2, and the undersize is subjected to conventional flotation to obtain a concentrate 3 and a tailings 3; (4) The concentrate 2 is ground and subjected to four times of concentrate heavy medium separation with the concentrate 3 to obtain a tungsten concentrate; The tailings obtained by the first time of concentrate heavy medium separation are subjected to flash flotation to obtain a concentrate 4 and a tailings 4, and the tailings obtained by the second time of concentrate heavy medium separation, the third time of concentrate heavy medium separation and the fourth time of concentrate heavy medium separation and the concentrate 4 are mixed as middlings and returned to the first time of concentrate heavy medium separation.
[0007] Optionally, in the process of heavy medium separation of the molybdenum tailings, the ore feeding concentration is 40-45% of -200 mesh.
[0008] Optionally, in the heavy medium separation process of molybdenum tailings, the heavy medium density is 1.62-1.70 g / cm 3 , and the discard rate is greater than or equal to 70%.
[0009] Optionally, in the grading process of the concentrate 1, a high-frequency screen with a mesh size of 100 is used.
[0010] Optionally, the ore concentration for coarse tungsten flotation is 35-40%; The coarse tungsten flotation reagent system: the collector is oxidized paraffin soap, and the dosage is 200-400 g / t; the dosage of sodium carbonate is 3000-4000 g / t.
[0011] Optionally, the coarse tungsten flotation uses a fluidized flotation column, the bed static pressure is 3.2-3.8 KPa, the rising water quantity is 15-18 L / min, and the gas quantity is 0.5-0.8 cm / s.
[0012] Optionally, the ore concentration for conventional flotation is 30-35%; The conventional flotation reagent system: the collector is benzo hydroxamic acid, and the dosage is 100-350 g / t; the dosage of sodium carbonate is 1000-2500 g / t.
[0013] Optionally, in the conventional flotation process, the reagent used also includes diethyl toluene diamine, and the dosage is 40-68 g / t.
[0014] Optionally, in the grinding process of the concentrate 2, the ore grinding concentration is 35-40%, and the ore discharge fineness is 65%-75% of -200 mesh.
[0015] Optionally, the ore concentration for flash flotation is 30-35%; The flash flotation reagent system: the collector is oxidized paraffin soap, and the dosage is 200-400 g / t; the dosage of sodium carbonate is 500-1000 g / t.
[0016] The method for recovering ultra-low-grade tungsten from molybdenum tailings provided in the application realizes the recovery of metal tungsten, and has the following beneficial effects compared with the prior art: (1) The application first realizes the pre-discarding of gangue minerals in molybdenum tailings by using heavy medium separation, reduces the energy consumption of subsequent production, improves the separation efficiency, then combines coarse tungsten particle flotation with conventional flotation, realizes the purpose of early discarding in the flotation stage, grinds the concentrate 2 obtained by coarse tungsten particle flotation, and then enriches the concentrate 3 obtained by conventional flotation, and performs four times of concentrate heavy medium separation, thereby improving the tungsten concentrate grade and reducing the production cost; the tailings obtained by the first concentrate heavy medium separation are subjected to flash flotation, which can effectively improve the recovery rate of tungsten in the concentration section, and through four times of heavy medium separation + flash flotation + middlings circulation multi-stage separation, the efficient recovery of high-density tungsten minerals is ensured.
[0017] (2) In the conventional flotation process, the application uses benzohydroxamic acid as the main collector and diethyl toluene diamine as the auxiliary collector. The hydroxamic acid functional group in the benzohydroxamic acid molecule can form a stable five-membered ring chelate with the metal cations on the surface of tungsten minerals, resulting in strong chemical adsorption and thus realizing hydrophobization. After the addition of diethyl toluene diamine, it can be adsorbed on the mineral surface together with benzohydroxamic acid, thereby increasing the overall hydrophobicity of the mineral particles and strengthening the collecting effect, especially for the capture of fine tungsten minerals and the improvement of the recovery rate. At the same time, the addition of diethyl toluene diamine not only reduces the dosage of benzohydroxamic acid, but also significantly improves the tungsten grade and the tungsten recovery rate.
[0018] (3) The method for recovering ultra-low-grade tungsten from molybdenum tailings provided by the application has a simple operation process, significantly improves the tungsten recovery and tungsten grade in the tungsten concentrate, and realizes efficient recovery of molybdenum resources in the molybdenum tailings. BRIEF DESCRIPTION OF DRAWINGS
[0019] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings described below are some embodiments of the application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.
[0020] Figure 1 The process flow chart of the method for recovering ultra-low-grade tungsten from molybdenum tailings provided by an embodiment of the application. DETAILED DESCRIPTION
[0021] In order to make the objects, technical solutions and advantages of the embodiments of the application clearer, the technical solutions in the embodiments of the application will be described clearly and completely below. Obviously, the described embodiments are some embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor also belong to the protection scope of the application.
[0022] As shown in Figure 1 , the application provides a method for recovering ultra-low-grade tungsten from molybdenum tailings, which comprises the following steps: (1) The molybdenum tailings are subjected to heavy medium separation to obtain a concentrate 1 and a tailings 1; (2) The concentrate 1 is subjected to classification to obtain an oversize and an undersize; (3) The oversize is subjected to coarse particle tungsten flotation to obtain a concentrate 2 and a tailings 2, and the undersize is subjected to conventional flotation to obtain a concentrate 3 and a tailings 3; (4) The concentrate 2 after grinding is subjected to four times of concentrate heavy medium separation with the concentrate 3 to obtain a tungsten concentrate; The tailings obtained by the first concentrate heavy medium separation are subjected to flash flotation to obtain a concentrate 4 and tailings 4, and the tailings obtained by the second, third and fourth concentrate heavy medium separation and the concentrate 4 are mixed as middlings and returned to the first concentrate heavy medium separation.
[0023] Specifically, in the present application, the molybdenum tailings (containing very low grade tungsten) are first placed in a heavy medium suspension, and heavy medium separation is performed by taking advantage of the difference in mineral density, i.e., the density of tungsten minerals > the density of gangue. Under a suitable medium density, high-density tungsten minerals enter the concentrate 1, and low-density gangue enters the tailings 1. This can discard a large amount of low-density gangue (such as quartz, calcite) in advance, achieve the purpose of early tailings rejection, and greatly reduce the subsequent production energy consumption and reagent consumption, thereby improving the separation efficiency. At the same time, it avoids the loss of tungsten minerals caused by over-grinding. The concentrate 1 is classified to obtain an oversize ore (coarse particles) and an undersize ore (fine particles), the oversize ore is subjected to coarse particle tungsten flotation to obtain a concentrate 2 and tailings 2, and the undersize ore is subjected to conventional flotation to obtain a concentrate 3 and tailings 3. The flotation behaviors of tungsten-containing minerals in coarse particles and fine particles are quite different, and the classification and subsequent flotation can improve the overall recovery rate. At the same time, the oversize ore and the undersize ore are treated separately, which can prevent the loss of the oversize ore in the conventional flotation due to insufficient bubble carrying capacity or failure to dissociate when they are treated together.
[0024] The reagent is added to the oversize ore for coarse particle tungsten flotation, and the hydrophobicity of the mineral particles adsorbed with the reagent is enhanced, so that the tungsten-containing mineral particles are firmly attached to the bubbles and are lifted by the bubbles to float to the surface of the ore slurry to form a froth layer, i.e., the flotation of tungsten-containing mineral particles is achieved. At the same time, the reagent is added to the undersize ore for conventional flotation, and the tungsten mineral particles in fine particles have a fast flotation speed and a high recovery efficiency, thereby improving the stability of the flotation. The concentrate 2 obtained by the coarse particle tungsten flotation is ground and re-enriched with the concentrate 3 obtained by the conventional flotation, and four-stage concentrate heavy medium separation is performed, and flash flotation is introduced in the tailings of the first stage of the heavy separation to quickly capture the difficult-to-separate particles and prevent them from entering the tailings. The subsequent heavy separation tailings and the flash flotation concentrate are returned to the first stage of the heavy separation as “middlings” to form a closed circuit. The four-stage concentrate heavy medium separation can gradually improve the grade of the tungsten concentrate. The four-stage heavy medium separation + flash flotation + middling circulation multi-stage separation ensures the efficient recovery of high-density tungsten minerals. During the four-stage concentrate heavy medium separation, the heavy medium density is 1.62-1.70 g / cm 3 .
[0025] Finally, the tailings 1, tailings 2, tailings 3 and tailings 4 are collected as total tailings, which are used as building materials or road paving materials for resource recovery.
[0026] The application first realizes pre-throwing of gangue minerals in molybdenum tailings by using heavy medium separation, reduces subsequent production energy consumption, and improves separation efficiency, then realizes the purpose of early throwing in the flotation stage by combining coarse tungsten particle flotation with conventional flotation, and the concentrate 2 obtained by the coarse particle tungsten flotation is re-enriched with the concentrate 3 obtained by the conventional flotation after being ground, and four times of concentrate heavy medium separation is carried out to improve the tungsten concentrate grade and reduce the production cost; the tailings obtained by the first concentrate heavy medium separation are subjected to flash flotation, which can effectively improve the recovery rate of the tungsten in the concentration section, and through four times of heavy medium separation + flash flotation + middlings recycling multi-stage separation, the efficient recovery of high-density tungsten minerals is ensured.
[0027] Optionally, in the process of heavy medium separation of molybdenum tailings, the feed concentration is 40-45% of-200 mesh.
[0028] Specifically, the control of the feed concentration can not only ensure that the pulp has sufficient viscosity to carry and suspend fine particle useful minerals, but also avoid excessive mudification to damage the entire heavy medium separation system. If the feed concentration is less than 40% of-200 mesh, the coarse particles in the pulp are more, the settling speed is fast, and turbulence or accumulation is easy to occur in the separation equipment, which affects the layering efficiency. More importantly, part of the dissociated fine tungsten minerals cannot effectively enter the heavy product due to insufficient pulp viscosity, resulting in premature loss. If the feed concentration is greater than 45% of-200 mesh, the pulp viscosity will increase significantly, resulting in poor medium fluidity and reduced separation accuracy.
[0029] Optionally, in the process of heavy medium separation of molybdenum tailings, the heavy medium density is 1.62-1.70 g / cm 3 , and the throwaway rate is greater than or equal to 70%.
[0030] Optionally, in the process of grading of the concentrate 1, a high-frequency screen with a screen hole of 100 mesh is used.
[0031] Optionally, the feed concentration for coarse particle tungsten flotation is 35-40%; The coarse particle tungsten flotation reagent system: the collector is oxidized paraffin soap, the dosage is 200-400 g / t; the dosage of sodium carbonate is 3000-4000 g / t.
[0032] Specifically, the feed concentration for coarse particle tungsten flotation is 35-40%, which significantly improves the collision frequency of tungsten mineral particles and bubbles in unit volume, thereby improving the tungsten recovery rate. At the same time, the control of stable feed concentration helps to form a foam with high mineral load, and such foam is more stable and can more effectively "lift" coarse particles to the surface of the flotation tank, preventing them from falling off midway due to their large mass, thereby directly improving the flotation rate and recovery rate of coarse tungsten minerals.
[0033] Oxidized paraffin soap is an anionic collector, and the main effective component is fatty acid and its soap, which is dissociated into RCOO- ions (Ca 2+ , Fe 2+ , Mn 2+ , etc.) on the surface of tungsten ore to form a hydrophobic film, providing strong and necessary surface hydrophobicity for coarse tungsten ore. The oxidized paraffin soap has strong collecting ability, especially suitable for coarse tungsten ore with low grade, low surface energy and poor floatability. It can provide sufficient hydrophobicity to overcome the problem of large mass of coarse tungsten ore and poor adhesion to bubbles. It has foaming property: the oxidized paraffin soap itself has certain foaming ability, which helps to generate foam with certain toughness, which is beneficial to carry coarse particles and thus improve the recovery rate of tungsten. Sodium carbonate as a regulator creates a stable weak alkaline environment (pH 9-10) for coarse tungsten flotation. In a weak alkaline environment, it helps the oxidized paraffin soap to exert the best collecting effect, and at the same time, it makes other gangues be inhibited. Calcium carbonate can form precipitates with calcium and magnesium ions in molybdenum tailings, reducing the consumption of these ions on the collector, and thus indirectly improving the flotation efficiency of tungsten.
[0034] Optionally, the coarse grade tungsten flotation uses a fluidized flotation column, the bed static pressure is 3.2-3.8 KPa, the upward water flow is 15-18 L / min, and the gas flow is 0.5-0.8 cm / s.
[0035] Specifically, the pressure of the fluidization state is controlled to be 3.2-3.8 KPa. In this state, the ore slurry is suspended by the upward water flow and bubbles, greatly increasing the contact time and contact area of coarse tungsten ore with bubbles. The upward water flow is the motive force for forming the fluidized bed of ore slurry, and the coarse tungsten ore needs a long enough residence time to ensure mineralization. The upward water flow is controlled to be 15-18 L / min, which will not cause the un-mineralized coarse particles to be washed into the foam due to too fast water flow, nor will it cause the bed to collapse and the coarse particles to settle due to too slow water flow. At the same time, the upward water flow cooperates with the upward bubbles, which is beneficial to generate larger and more stable bubbles, providing a favorable hydrodynamic environment for the countercurrent collision of coarse tungsten ore and bubbles, which is beneficial to improve the flotation efficiency of coarse grade tungsten flotation, achieve the purpose of separating as much tailings as possible, and improve the tungsten recovery grade. Optionally, the ore concentration during conventional flotation is 30-35%; The conventional flotation reagent system is: the collector is benzohydroxamic acid, the dosage is 100-350 g / t; the dosage of sodium carbonate is 1000-2500 g / t.
[0036] Specifically, benzohydroxamic acid is a chelating collector. The hydroxamic acid group (-C(NOH)OH) in its molecule can form a stable five-membered ring chelate with tungsten, which has high selectivity and strong binding force. Sodium carbonate is used to provide a weak alkaline environment (pH 8-10), which helps benzohydroxamic acid to stably exert its collecting effect in a weak alkaline environment. The combination of benzohydroxamic acid and sodium carbonate further improves the fineness of tungsten recovery.
[0037] Optionally, in conventional flotation processes, diethyltoluene diamine is also used, at a dosage of 40-68 g / t.
[0038] Specifically, in the conventional flotation process, in addition to using benzohydroxyxamic acid, diethyltoluenediamine is also added. Benzylhydroxyxamic acid is the dominant collector. The hydroxyxamic acid functional group in its molecule can form a stable five-membered ring chelate with the metal cations on the surface of tungsten minerals, resulting in strong chemical adsorption and thus achieving hydrophobicity.
[0039] Diethyltoluenediamine is an aromatic amine compound used as an auxiliary collector in flotation. Its two ethyl groups and benzene rings provide strong hydrophobicity, allowing it to adsorb onto the mineral surface along with benzo[a]hydroxyxamic acid, increasing the overall hydrophobicity of the mineral particles. This is particularly beneficial for capturing fine-grained tungsten ore and improving recovery. Simultaneously, the amine group (-NH-) can interact weakly with benzo[a]hydroxyxamic acid molecules or the mineral surface through hydrogen bonding or electrostatic interactions, forming a denser and more stable mixed adsorption layer, further enhancing the collection effect.
[0040] Optionally, during the grinding process of concentrate 2, the grinding concentration is 35-40%, and the discharge fineness is -200 mesh, accounting for 65%-75%.
[0041] Optionally, the feed concentration for flash flotation is 30-35%; Flash flotation reagent system: collector is oxidized paraffin soap, dosage 200-400 g / t; sodium carbonate dosage 500-1000 g / t.
[0042] The following are embodiments and effect test examples of the present invention, further describing the technical solution and technical effects of the present invention. However, the scope of protection of the present invention is not limited to these embodiments. Any changes or equivalent substitutions that do not depart from the concept of the present invention are within the scope of protection of the present invention. Furthermore, for those embodiments where specific technical operation steps or conditions are not specified, they are performed according to the techniques or conditions described in general literature in the art or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially. The ore concentrations mentioned in this application are all mass concentrations. Example 1
[0043] A method for recovering ultra-low grade tungsten from molybdenum tailings, the method comprising the following steps: (1) Molybdenum tailings with a tungsten grade of 0.0452% were subjected to heavy media separation to obtain concentrate 1 and tailings 1; The feed concentration for heavy media separation of molybdenum tailings is -200 mesh, accounting for 40-45%, and the density of the heavy media is 1.63 g / cm³. 3 Waste rate ≥70%; (2) The concentrate 1 is classified by a high-frequency screen with a mesh size of 100 meshes to obtain oversize and undersize ores; (3) The oversize ore is subjected to coarse-grained tungsten flotation to obtain a concentrate 2 and a tailing 2, and the ore concentration is 35%; the coarse-grained tungsten flotation reagent system: the collector is oxidized paraffin soap, the dosage is 250 g / t; the sodium carbonate dosage is 3200 g / t; the coarse-grained tungsten flotation uses a fluidized flotation column, the bed static pressure is 3.2 KPa, the rising water volume is 15 L / min, and the gas volume is 0.5 cm / s; The undersize ore is subjected to conventional flotation to obtain a concentrate 3 and a tailing 3; the ore concentration is 32%, and the conventional flotation reagent system: the collector is benzohydroxamic acid, the dosage is 200 g / t; the sodium carbonate dosage is 1500 g / t; (4) The concentrate 2 is ground to a concentration of 35% and a discharge fineness of -200 meshes accounting for 65%-75%, and then subjected to four times of concentrate heavy medium separation with the concentrate 3 to obtain a tungsten concentrate; The tailings obtained by the first time of concentrate heavy medium separation are subjected to flash flotation to obtain a concentrate 4 and a tailing 4, and the ore concentration is 30% during the flash flotation; the flash flotation reagent system: the collector is oxidized paraffin soap, the dosage is 200 g / t; the sodium carbonate dosage is 500 g / t. The tailings obtained by the second, third and fourth times of concentrate heavy medium separation and the concentrate 4 are mixed as middlings and returned to the first time of concentrate heavy medium separation. During the four times of concentrate heavy medium separation, the heavy medium density is 1.66 g / cm 3 . Example 2
[0044] A method for recovering ultra-low-grade tungsten from molybdenum tailings, comprising the following steps: (1) The molybdenum tailings with a tungsten grade of 0.0475% are subjected to heavy medium separation to obtain a concentrate 1 and a tailing 1; The molybdenum tailings heavy medium separation ore concentration is -200 meshes accounting for 40-45%, the heavy medium density is 1.65 g / cm 3 , and the discard rate is ≥70%; (2) The concentrate 1 is classified by a high-frequency screen with a mesh size of 100 meshes to obtain oversize and undersize ores; (3) The oversize ore is subjected to coarse-grained tungsten flotation to obtain a concentrate 2 and a tailing 2, and the ore concentration is 38%; the coarse-grained tungsten flotation reagent system: the collector is oxidized paraffin soap, the dosage is 280 g / t; the sodium carbonate dosage is 3500 g / t; the coarse-grained tungsten flotation uses a fluidized flotation column, the bed static pressure is 3.4 KPa, the rising water volume is 17 L / min, and the gas volume is 0.6 cm / s; The undersize ore is subjected to conventional flotation to obtain a concentrate 3 and a tailing 3; the ore concentration is 30%, and the conventional flotation reagent system: the collector is benzohydroxamic acid, the dosage is 200 g / t; the sodium carbonate dosage is 1500 g / t; (4) the concentrate 2 is ground at a grinding concentration of 33% and a discharge fineness of -200 mesh accounting for 65%-75%, and then is subjected to four times of concentrate heavy medium separation with the concentrate 3 to obtain a tungsten concentrate; The tailings obtained by the first time of concentrate heavy medium separation are subjected to flash flotation to obtain a concentrate 4 and tailings 4, and the ore feeding concentration during the flash flotation is 35%; the flash flotation reagent system is as follows: the collector is oxidized paraffin soap, and the dosage is 280 g / t; the dosage of sodium carbonate is 600 g / t. The tailings obtained by the second time of concentrate heavy medium separation, the third time of concentrate heavy medium separation, and the fourth time of concentrate heavy medium separation, and the concentrate 4 are mixed as middlings and returned to the first time of concentrate heavy medium separation. During the four times of concentrate heavy medium separation, the heavy medium density is 1.68 g / cm 3 . Example 3
[0045] A method for recovering ultra-low-grade tungsten from molybdenum tailings, comprising the following steps: (1) The molybdenum tailings with a tungsten grade of 0.0460% are subjected to heavy medium separation to obtain a concentrate 1 and tailings 1; The ore feeding concentration of the molybdenum tailings for heavy medium separation is -200 mesh accounting for 40-45%, the heavy medium density is 1.68 g / cm 3 , and the rejection rate is ≥70%; (2) The concentrate 1 is classified by a high-frequency screen with a screen aperture of 100 mesh to obtain an oversize and an undersize; (3) The oversize is subjected to coarse-grained tungsten flotation to obtain a concentrate 2 and tailings 2, and the ore feeding concentration is 40%; the coarse-grained tungsten flotation reagent system is as follows: the collector is oxidized paraffin soap, and the dosage is 400 g / t; the dosage of sodium carbonate is 4000 g / t; the coarse-grained tungsten flotation adopts a fluidized flotation column, the bed static pressure is 3.8 KPa, the rising water amount is 18 L / min, and the gas amount is 0.8 cm / s; The undersize is subjected to conventional flotation to obtain a concentrate 3 and tailings 3; the ore feeding concentration is 35%, and the conventional flotation reagent system is as follows: the collector is benzohydroxamic acid, and the dosage is 350 g / t; the dosage of sodium carbonate is 2500 g / t; (4) The concentrate 2 is ground at a grinding concentration of 40% and a discharge fineness of -200 mesh accounting for 65%-75%, and then is subjected to four times of concentrate heavy medium separation with the concentrate 3 to obtain a tungsten concentrate; The tailings obtained by the first time concentrate heavy medium separation are subjected to flash flotation to obtain concentrate 4 and tailings 4, and the ore concentration during the flash flotation is 35%; the flash flotation reagent system: the collector is oxidized paraffin soap, the dosage is 400 g / t; the dosage of sodium carbonate is 1000 g / t. The tailings and the concentrate 4 obtained by the second time concentrate heavy medium separation, the third time concentrate heavy medium separation and the fourth time concentrate heavy medium separation are mixed as middlings and returned to the first time concentrate heavy medium separation. During the four times of concentrate heavy medium separation, the heavy medium density is 1.70 g / cm 3 .
[0046] Comparative Example 1 A method for recovering ultra-low-grade tungsten from molybdenum tailings, the method comprising the following steps: The difference from Example 2 is that: (1) The molybdenum tailings with a tungsten grade of 0.0513% are subjected to heavy medium separation to obtain concentrate 1 and tailings 1; (2) The concentrate 1 is not subjected to screening and is directly subjected to conventional flotation.
[0047] The yield, tungsten grade and tungsten recovery rate of the molybdenum tailings, tungsten concentrate and final total tailings in Example 1-Example 3 and Comparative Example 1 are summarized in Table 1, and the results are shown in the following table.
[0048] Table 1
[0049] As can be seen from Table 1, the tungsten concentrate obtained by the tungsten recovery scheme provided in Example 1-Example 3 has a tungsten grade of >20% and a tungsten recovery rate of >50%, achieving efficient recovery of tungsten from molybdenum tailings. By comparing Example 1-Example 3 with Comparative Example 1, first, the molybdenum tailings are subjected to heavy medium separation to discard tailings, reducing the energy consumption of subsequent production and improving the separation efficiency. Then, the concentrate 1 obtained by the heavy medium separation of the molybdenum tailings is screened, and the coarse tungsten particle flotation of the oversize ore and the conventional flotation of the undersize ore are combined. Not only does this separate the ore according to particle size, improving the flotation efficiency, but it also achieves the goal of early discarding in the flotation stage. Finally, the concentrate 2 obtained by the coarse particle tungsten flotation is ground and combined with the concentrate 3 obtained by the conventional flotation to enrich the tungsten concentrate, and the tungsten concentrate is subjected to four times of concentrate heavy medium separation to improve the tungsten concentrate grade and reduce the production cost.
[0050] Example 4 A method for recovering ultra-low-grade tungsten from molybdenum tailings, the method comprising the following steps: The difference from Example 2 is that: (1) The molybdenum tailings with a tungsten grade of 0.0561% are subjected to heavy medium separation to obtain concentrate 1 and tailings 1; (3) the undersize ore is subjected to conventional flotation to obtain concentrate 3 and tailings 3; the ore feeding concentration is 35%, and the conventional flotation reagent system is as follows: the collector is benzo hydroxamic acid, the dosage is 337 g / t, the auxiliary collector is diethyl toluene diamine, the dosage is 40 g / t, and the dosage of sodium carbonate is 2500 g / t.
[0051] Example 5 A method for recovering ultra-low-grade tungsten from molybdenum tailings, comprising the following steps: The difference from Example 2 is that: (1) the molybdenum tailings with a tungsten grade of 0.0503% are subjected to heavy medium separation to obtain concentrate 1 and tailings 1; (3) the undersize ore is subjected to conventional flotation to obtain concentrate 3 and tailings 3; the ore feeding concentration is 35%, and the conventional flotation reagent system is as follows: the collector is benzo hydroxamic acid, the dosage is 329 g / t, the auxiliary collector is diethyl toluene diamine, the dosage is 68 g / t, and the dosage of sodium carbonate is 2500 g / t.
[0052] Example 6 A method for recovering ultra-low-grade tungsten from molybdenum tailings, comprising the following steps: The difference from Example 2 is that: (1) the molybdenum tailings with a tungsten grade of 0.0503% are subjected to heavy medium separation to obtain concentrate 1 and tailings 1; (3) the undersize ore is subjected to conventional flotation to obtain concentrate 3 and tailings 3; the ore feeding concentration is 35%, and the conventional flotation reagent system is as follows: the collector is benzo hydroxamic acid, the dosage is 329 g / t, the auxiliary collector is diethyl toluene diamine, the dosage is 68 g / t, and the dosage of sodium carbonate is 2500 g / t.
[0053] Comparative Example 2 A method for recovering ultra-low-grade tungsten from molybdenum tailings, comprising the following steps: The difference from Example 2 is that: (1) the molybdenum tailings with a tungsten grade of 0.0503% are subjected to heavy medium separation to obtain concentrate 1 and tailings 1; (3) the undersize ore is subjected to conventional flotation to obtain concentrate 3 and tailings 3; the ore feeding concentration is 35%, and the conventional flotation reagent system is as follows: the collector is benzo hydroxamic acid, the dosage is 329 g / t, the auxiliary collector is diethyl toluene diamine, the dosage is 68 g / t, and the dosage of sodium carbonate is 2500 g / t.
[0054] Comparative Example 3 A method for recovering ultra-low-grade tungsten from molybdenum tailings, comprising the following steps: The difference from Example 2 is that: (1) the molybdenum tailings with a tungsten grade of 0.0503% are subjected to heavy medium separation to obtain concentrate 1 and tailings 1; (3) The undersize ore is subjected to conventional flotation to obtain concentrate 3 and tailings 3; the ore feed concentration is 35%, and the conventional flotation reagent system is: the collector is benzohydroxamic acid, the dosage is 350 g / t, the auxiliary collector is diethyl toluene diamine, the dosage is 38 g / t, and the dosage of sodium carbonate is 2500 g / t.
[0055] The yield, tungsten grade, and tungsten recovery of the molybdenum ore tailings, tungsten concentrate, and final total tailings in Example 4-Example 6, Comparative Example 2, and Comparative Example 3 are summarized in Table 2, and the results are shown in the following table.
[0056] Table 2
[0057] As can be seen from Table 2, the tungsten grade and tungsten recovery of Examples 4-6 are significantly improved compared to Comparative Examples 2 and 3. Benzohydroxamic acid is used as the main collector, and diethyl toluene diamine is used as the auxiliary collector. The hydroxamic acid functional group in the benzohydroxamic acid molecule can form a stable five-membered ring chelate with the metal cations on the surface of the tungsten ore, resulting in strong chemical adsorption and thus hydrophobization. At the same time, after the addition of diethyl toluene diamine, it can be adsorbed on the mineral surface together with benzohydroxamic acid, which can increase the overall hydrophobicity of the mineral particles and strengthen the collecting effect, especially for the capture of fine tungsten ore, thereby improving the recovery rate. At the same time, the addition of diethyl toluene diamine not only reduces the dosage of benzohydroxamic acid, but also significantly improves the tungsten grade and tungsten recovery.
[0058] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that; they can still modify the technical solutions described in the foregoing examples, or make equivalent substitutions for part or all of the technical features; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.
Claims
1. A method for recovering ultra-low grade tungsten from molybdenum tailings, characterized in that, Includes the following steps: (1) The molybdenum tailings were subjected to heavy media separation to obtain concentrate 1 and tailings 1; (2) The concentrate 1 is classified to obtain oversize ore and undersize ore; (3) The oversize ore is subjected to coarse-grained tungsten flotation to obtain concentrate 2 and tailings 2, and the undersize ore is subjected to conventional flotation to obtain concentrate 3 and tailings 3; (4) After grinding the concentrate 2, it is subjected to four heavy media separations with the concentrate 3 to obtain tungsten concentrate; In this process, the tailings obtained from the first heavy media separation of concentrate are subjected to flash flotation to obtain concentrate 4 and tailings 4. The tailings obtained from the second, third, and fourth heavy media separation of concentrate and concentrate 4 are mixed with concentrate 4 to form middlings and returned to the first heavy media separation of concentrate.
2. The method for recovering ultra-low grade tungsten from molybdenum tailings according to claim 1, characterized in that, During the heavy media separation process of the molybdenum tailings, the feed concentration is -200 mesh, accounting for 40-45%.
3. The method for recovering ultra-low grade tungsten from molybdenum tailings according to claim 1, characterized in that, In the heavy medium separation process of the molybdenum tailings, the density of the heavy medium is 1.62-1.70 g / cm³. 3 The waste rate is ≥70%.
4. The method for recovering ultra-low grade tungsten from molybdenum tailings according to claim 1, characterized in that, During the grading process of the concentrate 1, a high-frequency sieve with a 100-mesh aperture is used.
5. The method for recovering ultra-low grade tungsten from molybdenum tailings according to claim 1, characterized in that, The feed concentration for coarse-grained tungsten flotation is 35-40%. Coarse-grained tungsten flotation reagent system: collector is oxidized paraffin soap, dosage 200-400 g / t; sodium carbonate dosage 3000-4000 g / t.
6. The method for recovering ultra-low grade tungsten from molybdenum tailings according to claim 1, characterized in that, The coarse-grained tungsten flotation adopts a fluidized bed flotation column with a bed static pressure of 3.2-3.8 kPa, a water flow rate of 15-18 L / min, and a gas flow rate of 0.5-0.8 cm / s.
7. The method for recovering ultra-low grade tungsten from molybdenum tailings according to claim 1, characterized in that, The feed concentration during conventional flotation is 30-35%; The conventional flotation reagent system is as follows: the collector is benzohydroxyxamic acid, with a dosage of 100-350 g / t; the dosage of sodium carbonate is 1000-2500 g / t.
8. The method for recovering ultra-low grade tungsten from molybdenum tailings according to claim 7, characterized in that, In the conventional flotation process, the reagents used also include diethyltoluene diamine, at a dosage of 40-68 g / t.
9. The method for recovering ultra-low grade tungsten from molybdenum tailings according to claim 1, characterized in that, During the grinding process of concentrate 2, the grinding concentration is 35-40%, and the discharge fineness is -200 mesh, accounting for 65%-75%.
10. The method for recovering ultra-low grade tungsten from molybdenum tailings according to any one of claims 1-9, characterized in that, The feed concentration during flash flotation is 30-35%; The flash flotation reagent system is as follows: the collector is oxidized paraffin soap, with a dosage of 200-400 g / t; the dosage of sodium carbonate is 500-1000 g / t.