Method for comprehensive utilization of low-grade fine tungsten-tin

Abstract

This invention discloses a method for the comprehensive utilization of low-grade, fine-grained tungsten and tin, relating to the field of mineral processing technology. The invention utilizes advanced flotation equipment and reagents, comprising the following steps: raw tungsten and tin ore is concentrated, doped with reagents, stirred, and pumped to a desulfurization process. The desulfurization process employs a one-stage roughing and one-stage cleaning process. The desulfurization tailings enter the tungsten-tin flotation process, which employs a one-stage roughing, two-stage cleaning, and two-stage scavenging process, ultimately achieving the comprehensive recovery and utilization of low-grade, fine-grained tungsten and tin. When the raw ore is low-grade (WO3 0.20%-0.40%, Sn 0.10%-0.30%), a mixed concentrate with WO3+Sn>24% can be obtained, with a tungsten recovery rate ≥76% and a tin recovery rate ≥59%. This invention features simple equipment and low reagent costs, and is applicable to the comprehensive recovery and utilization of similar low-grade, fine-grained tungsten and tin ore, offering considerable economic and environmental benefits. Compared with existing technologies, it has significant advantages, improving enterprise economic efficiency and reducing resource waste.

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology, and in particular to a method for the comprehensive utilization of low-grade fine-grained tungsten and tin. Background Technology

[0002] Tungsten and tin possess excellent physicochemical properties and are strategically important metallic resources, widely used in alloy materials, semiconductors, aerospace, and other fields. In tungsten-silver symbiotic deposits, tungsten ore is often associated with cassiterite, exhibiting fine grain size and complex mineral composition, making it a typical type of refractory ore that is difficult to separate.

[0003] Chinese patent application CN116060204A discloses a novel process for the efficient and rapid separation of tungsten-tin fine mud using a blanket process. This process involves sequentially passing the raw ore through large-pitch spiral sluices, medium-pitch spiral sluices, and small-pitch spiral sluices for gravity separation and roughing. A hydraulic classifying shaking table system is used to classify the incoming material in the spiral sluices and then convey it to different shaking tables for further processing. Different troughs on the shaking tables are used to recover ore of different particle sizes. However, this method is more suitable for general coarse-grained tungsten-tin mixed ores; it is still difficult to effectively separate low-grade, fine-grained tungsten-tin mixed ores. Low-grade, fine-grained tungsten-tin mixed ores are generally recovered using flotation methods.

[0004] Because the grade of low-grade fine-grained tungsten and tin fluctuates greatly, and the particles processed by flotation are all fine-grained, which have the characteristics of small mass and large specific surface area, the application of traditional flotation equipment is limited to a certain extent, affecting the final grade and recovery rate of the metal.

[0005] Chinese patent CN111495579A discloses a method for recovering tungsten and tin from fine mud and sand. This method involves flotation desulfurization roughing-scavenging, tungsten-tin mixed flotation roughing-scavenging, magnetic separation roughing-cleaning, and flotation separation roughing-cleaning operations on the fine mud and sand to be selected, ultimately yielding scheelite concentrate and tin concentrate. Chinese patent CN107617508A discloses a beneficiation process for fine-grained tungsten-tin associated minerals. This process employs gravity separation with tailings pre-selection, reverse flotation desulfurization and desilication, and magnetic separation of wolframite and cassiterite. The above-disclosed prior art has certain limitations. When using traditional flotation equipment and reagent systems, it is difficult to effectively recover fine particles, resulting in low system recovery rate, low concentrate grade, poor separation effect, and relatively low throughput. Furthermore, the current processes used for low-grade, fine-grained tungsten and tin are complex and cumbersome, which is not conducive to their industrial application.

[0006] The above background information is provided only to aid in understanding the inventive concept and technical solution of this invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this patent application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0007] To address the shortcomings of existing technologies for the comprehensive utilization and recovery of low-grade fine-particle tungsten and tin, this invention proposes a method for the comprehensive utilization of low-grade fine-particle tungsten and tin, employing novel flotation equipment and mineral processing reagents to significantly improve the grade and recovery rate of tungsten and tin.

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

[0009] A method for the comprehensive utilization of low-grade fine-grained tungsten-tin particles, using advanced flotation equipment systems and mineral processing reagents;

[0010] The advanced flotation equipment system includes a thickener, a desulfurization roughing flotation column, a desulfurization cleaning flotation column, a tungsten-tin roughing flotation column, a tungsten-tin scavenging flotation column (first stage), a tungsten-tin scavenging flotation column (second stage), a tungsten-tin cleaning flotation column (first stage), a tungsten-tin cleaning flotation column (second stage), and each equipped with a slurry mixing tank.

[0011] Furthermore, the thickener outlet is connected to the feed inlet of the desulfurization roughing agitator; the desulfurization roughing agitator is connected to the feed inlet of the desulfurization roughing flotation column via a pipeline; the concentrate overflow outlet of the desulfurization roughing flotation column is connected to the desulfurization cleaning agitator via a pipeline; the tailings underflow outlet of the desulfurization roughing flotation column is connected to the tungsten-tin roughing agitator via a pipeline; the desulfurization cleaning agitator is connected to the feed inlet of the desulfurization cleaning flotation column via a pipeline; and the concentrate overflow outlet of the desulfurization cleaning flotation column is transported to the pump via a pipeline. The tailings underflow from the desulfurization and cleaning flotation column is returned to the desulfurization roughing mixing tank via pipeline; the tungsten-tin roughing mixing tank is connected to the feed inlet of the tungsten-tin roughing flotation column via pipeline; the concentrate overflow from the tungsten-tin roughing flotation column is connected to the tungsten-tin cleaning mixing tank via pipeline; the tailings underflow from the tungsten-tin roughing flotation column is connected to the tungsten-tin scavenging mixing tank via pipeline; the tungsten-tin scavenging mixing tank is connected to the feed inlet of the tungsten-tin scavenging flotation column via pipeline; the concentrate overflow from the tungsten-tin scavenging flotation column... The feed inlet of the first tungsten-tin roughing flotation column is connected to the tungsten-tin roughing mixing tank via a pipeline; the tailings underflow outlet of the first tungsten-tin scavenging flotation column is connected to the second tungsten-tin scavenging mixing tank via a pipeline; the feed inlet of the first tungsten-tin cleaning flotation column is connected to the feed outlet of the first tungsten-tin cleaning flotation column via a pipeline; the concentrate overflow outlet of the first tungsten-tin cleaning flotation column is connected to the second tungsten-tin cleaning mixing tank via a pipeline; the tailings underflow outlet of the first tungsten-tin cleaning flotation column returns to the tungsten-tin roughing mixing tank via a pipeline; the feed inlet of the second tungsten-tin scavenging mixing tank is connected to the feed outlet of the second tungsten-tin scavenging flotation column via a pipeline. The concentrate overflow outlet of the scavenging flotation column 2 is connected to the mixing tank of the scavenging flotation column 1 via pipelines. The tailings underflow outlet of the scavenging flotation column 2 is transported to the thickener and then to the tailings pump pool via pipelines. The mixing tank of the scavenging flotation column 2 is connected to the feed inlet of the scavenging flotation column 2 via pipelines. The concentrate overflow outlet of the scavenging flotation column 2 is transported to the scavenging flotation column 1 via pipelines. The tailings underflow outlet of the scavenging flotation column 2 is returned to the mixing tank of the scavenging flotation column 1 via pipelines.

[0012] Furthermore, each of the stirring tanks of the desulfurization roughing flotation column, the desulfurization cleaning flotation column, the tungsten-tin roughing flotation column, the tungsten-tin scavenging flotation column (first stage), the tungsten-tin scavenging flotation column (second stage), the tungsten-tin cleaning flotation column (first stage), and the tungsten-tin cleaning flotation column (second stage) is equipped with a feed pump to transport the slurry to the corresponding flotation column inlet.

[0013] Furthermore, the desulfurization roughing flotation column, the desulfurization cleaning flotation column, the tungsten-tin roughing flotation column, the tungsten-tin scavenging flotation column (first stage), the tungsten-tin scavenging flotation column (second stage), the tungsten-tin cleaning flotation column (first stage), and the tungsten-tin cleaning flotation column (second stage) are all equipped with self-circulating pumps.

[0014] Furthermore, the mineral processing reagents include modifiers, collectors, and frothers.

[0015] Furthermore, the aforementioned mineral processing reagents are added to the slurry in specific amounts at each stage of the tungsten-tin desulfurization and tin-tungsten mixed flotation processes. The types and amounts of mineral processing reagents added at each stage are as follows:

[0016] Desulfurization stage:

[0017] Copper sulfate is used as a modifier for activation, with a dosage of 50-150 g / t;

[0018] No. 2 oil is used as a foaming agent, with a dosage of 2-30g / t;

[0019] The use of butyl xanthate as a collector for sulfide mineral collection is 30-200 g / t.

[0020] Mixed flotation stage:

[0021] Sodium carbonate is used as a modifier to soften water and adjust the pH of the slurry, with a dosage of 300-900 g / t.

[0022] Lead nitrate was used as a modifier for tungsten-tin activation, with a dosage of 150-450 g / t.

[0023] Acidified water glass is used as a modifier to suppress iron-containing impurities and silicates, with a dosage of 30-300 g / t;

[0024] GY-1, which has excellent tungsten-tin collecting properties and selectivity, is used as a tungsten-tin collector at a dosage of 10-200 g / t, while GY-2 is used as an auxiliary tungsten-tin collector at a dosage of 1-10 g / t.

[0025] A method for the comprehensive utilization of low-grade fine-grained tungsten-tin includes the following steps:

[0026] Step (1): Concentration: Low-grade fine-grained tungsten-tin ore slurry is concentrated using a thickener;

[0027] Step (2): Desulfurization: The concentrated low-grade fine-grained tungsten-tin ore slurry is desulfurized through a desulfurization flotation column; the underflow slurry of thickener 1 is conditioned by adding modifier, collector and frother in the desulfurization roughing mixing tank, and the conditioned slurry is fed into the desulfurization roughing flotation column by a feed pump. The concentrate from the desulfurization roughing flotation column flows into the desulfurization cleaning flotation column, and the tailings from the desulfurization roughing flotation column are fed into the tungsten-tin roughing mixing tank with modifier and collector for slurry conditioning, and then fed into the tungsten-tin roughing flotation column by a feed pump.

[0028] Step (3): Mixed flotation: After desulfurization, the low-grade fine-grained tungsten-tin ore slurry undergoes mixed flotation of tin and tungsten through each flotation column; the concentrate from the tungsten-tin rougher flotation column flows into the tungsten-tin cleaner first stirring tank, where a modifier is added for slurry conditioning, and then fed into the tungsten-tin cleaner first flotation column via a feed pump; the tailings from the tungsten-tin rougher flotation column are fed into the tungsten-tin scavenger first stirring tank, where modifiers and collectors are added for slurry conditioning, and then fed into the tungsten-tin scavenger first flotation column via a feed pump; the concentrate from the tungsten-tin cleaner first flotation column flows into the tungsten-tin cleaner second stirring tank, where a collector is added for slurry conditioning, and then fed into the tungsten-tin cleaner second flotation column via a feed pump; the tailings from the tungsten-tin cleaner first flotation column are returned to the tungsten-tin rougher flotation column. The process involves selecting a mixing tank to achieve a closed-loop circulation. The concentrate from the first scavenging flotation column of tungsten-tin is returned to the roughing mixing tank of tungsten-tin, while the tailings from the first scavenging flotation column are fed into the second scavenging flotation column of tungsten-tin with collectors for slurry preparation, and then fed into the second scavenging flotation column of tungsten-tin via a feed pump. The concentrate from the second scavenging flotation column of tungsten-tin is returned to the first scavenging flotation tank of tungsten-tin, while the tailings from the second scavenging flotation column of tungsten-tin enter the thickener and then flow into the tailings pump pool for pumping away. The concentrate from the second scavenging flotation column of tungsten-tin concentrate flows into the tungsten-tin concentrate pump pool for pumping away, while the tailings from the second scavenging flotation column of tungsten-tin concentrate return to the first scavenging flotation tank of tungsten-tin concentrate, thus achieving a closed-loop circulation and producing a mixed tungsten-tin concentrate.

[0029] The technical principles and beneficial effects of this invention include:

[0030] I. Technical Principles

[0031] 1. Flotation equipment system principle:

[0032] In the beneficiation process of low-grade, fine-grained tungsten-tin ore, the thickener, as a key pretreatment device, bears the heavy responsibility of controlling the pulp concentration. Given the inconsistent concentrations and complex composition of the raw pulp, it is difficult to directly adapt it to subsequent flotation operations. The thickener's gravity settling efficiency allows for efficient pulp concentration within the thickener. After the pulp flows into the thickener, solid particles gradually settle to the bottom under gravity, while water continuously overflows upwards, thus precisely controlling the pulp concentration within the ideal range of 30%-50%. The precise setting of this concentration range has a profound impact on the subsequent flotation results. If the concentration is too low, the flotation reagents cannot fully contact the ore particles and react chemically, resulting in a significant reduction in flotation efficiency; if the concentration is too high, the pulp viscosity increases, resulting in poor flowability and easily causing equipment blockages, which is also detrimental to the orderly conduct of flotation operations.

[0033] The concentrated slurry is then transported to the desulfurization roughing flotation column to officially begin the desulfurization process. In this stage, copper sulfate, acting as a modifier, plays its role first. Its excellent chemical activity allows it to rapidly penetrate the crystal lattice of the sulfide ore, altering the surface chemical properties and adjusting the potential, thus effectively activating the ore and laying a solid foundation for subsequent efficient synergistic reactions with the collector. The added No. 2 oil, a typical surfactant, rapidly reduces the surface tension of the slurry. With the aid of mechanical agitation, it promotes the continuous generation of a large amount of fine, stable, and resilient foam. These foams, with their excellent buoyancy, act like a carrier, steadily lifting the activated sulfide ore particles. Next, butyl xanthate, with its unique chemical affinity for sulfide ore, precisely adheres to the surface of the sulfide ore, efficiently collecting it through chemical bonding or physical adsorption, achieving the initial separation of sulfide ore from tungsten-tin ore.

[0034] The slurry after sulfide removal flows into the tungsten-tin roughing flotation column. Subsequent tungsten-tin scavenging flotation columns (first, second, third, and fourth stages) work in tandem to form a comprehensive and refined flotation system. Between each flotation column, the mixing tank is responsible for uniformly mixing the slurry and reagents, using high-speed agitation to ensure thorough mixing. The feed pump precisely controls the flow rhythm of the slurry between columns, ensuring stable and efficient transport. Crucially, each flotation column is equipped with a self-circulating pump that continuously extracts a portion of the slurry for recirculation, thereby enhancing the turbulence and mixing within the slurry. In this way, tungsten-tin minerals of different particle sizes and properties—whether micron-sized particles or larger ones, highly chemically active or relatively inert—can find suitable separation conditions in a dynamically optimized flotation environment, ultimately achieving precise separation and efficient enrichment.

[0035] 2. Principle of mineral processing reagents:

[0036] During the desulfurization stage, various mineral processing reagents perform their respective functions and work together to complete the separation of sulfide ores. Copper sulfate acts as an activator for sulfide ores. When it is added to the slurry, it quickly ionizes into copper ions. With its unique chemical activity, the copper ions precisely replace some of the ions on the surface of the sulfide ores, causing a change in the surface properties of the sulfide ores from their original low-activity state to an active state that is more likely to react with the collector, laying a solid foundation for the smooth progress of subsequent collection operations. No. 2 oil, as a foaming agent, belongs to the category of surfactants. When added to the slurry, it can quickly reduce the surface tension of the liquid. Under the synergistic effect of mechanical stirring, a large amount of air is entrained into the slurry. The No. 2 oil molecules are arranged in an orderly manner at the gas-liquid interface, encapsulating the air bubbles and promoting the formation of fine and stable foam. These foams, with their excellent buoyancy, efficiently carry sulfide mineral particles to the surface of the slurry, achieving the initial separation purpose; while butyl xanthate, as a professional sulfide mineral collector, precisely locks onto sulfide minerals by virtue of the strong chemical affinity between sulfur atoms in its molecular structure and sulfide minerals, and firmly collects sulfide minerals through chemical bonding, physical adsorption and other methods.

[0037] In the mixed flotation stage, sodium carbonate, as a key reagent for water purification and pH adjustment, is introduced first. The pulp typically contains various metal ions and impurities, which sodium carbonate can chemically react with to promote the precipitation of these impurities, thus softening the water. Simultaneously, it precisely adjusts the pH of the pulp, creating a weakly alkaline environment suitable for the flotation characteristics of tungsten and tin minerals. This ensures that subsequently added reagents maintain good chemical activity, guaranteeing a stable and efficient flotation reaction. Lead nitrate acts as an activator for tungsten-tin minerals. Upon addition to the slurry, it rapidly ionizes, generating lead ions that tightly adsorb onto the surface of the minerals. This effectively fills the charge vacancies in the mineral lattice, altering the charge distribution and hydration film thickness, significantly enhancing the natural floatability of tungsten-tin minerals and making them easier to combine with air bubbles and float during flotation. Acidified water glass plays a crucial role in suppressing impurities. For common iron-containing impurities and silicates in the slurry, it utilizes the polymerization and precipitation of silicate ions and complexation reactions with metal ions to firmly bind these impurities, inhibiting their flotation ability and causing them to settle to the bottom of the slurry. This comprehensively ensures the purity and quality of the tungsten-tin concentrate. GY-1 and GY-2, as professional tungsten-tin collectors, exhibit excellent collection and selectivity for tungsten-tin minerals due to their superior molecular structure design and chemical activity. They can accurately identify active sites on the surface of tungsten-tin minerals and efficiently adhere to them through multiple methods such as chemical bonding and physical adsorption, escorting them to float smoothly, overcoming the obstacles of gangue minerals, and achieving precise separation of tungsten-tin from other gangue minerals, thereby effectively improving the grade and recovery rate of tungsten-tin.

[0038] II. Beneficial Effects

[0039] 1. Improved Resource Utilization: In the field of mineral resource development, the grade of the raw ore is one of the key factors determining the effectiveness of resource recovery. Low-grade, fine-grained tungsten-tin ore has always been a thorny problem in mineral processing. This type of ore not only has low tungsten and tin content, but also fine mineral particle size and complex composition, making it difficult for traditional beneficiation processes to accurately separate and efficiently recover resources, resulting in widespread resource waste. This method, with a raw ore grade of 0.20%-0.40% WO3 and 0.10%-0.30% Sn, can achieve a final product of a tungsten-tin mixed concentrate with WO3+Sn>24%, where the tungsten recovery rate is ≥76% and the tin recovery rate is ≥59%, representing a significant leap compared to traditional processes. This is thanks to the meticulous control over each stage of flotation, from adjusting the pulp concentration and precisely adding reagents to the efficient collaboration of advanced flotation equipment systems. This comprehensively promotes the full dissociation and precise enrichment of tungsten and tin minerals in the ore, making full use of the valuable resources hidden in fine-grained ore, effectively reducing resource idleness and loss, and powerfully promoting the sustainable development and utilization of metal resources, which is in line with the industry's vision of efficient resource recycling.

[0040] 2. Significant Economic Benefits: In the cost control of mineral processing enterprises, equipment and reagent costs are key components. Traditional mineral processing equipment systems, designed to adapt to complex working conditions, have complex architectures and numerous components, requiring substantial initial investment. Installation is cumbersome, time-consuming, and labor-intensive. During operation and maintenance, frequent malfunctions necessitate frequent replacement of parts and the hiring of specialized technicians, resulting in persistently high costs. In contrast, the equipment layout adopted in this invention is simple and ingenious, optimized according to the actual needs of ore processing, eliminating redundant structures and effectively reducing procurement costs. The installation process is simplified, significantly shortening the construction cycle and reducing labor and time costs. Equipment stability is enhanced, the failure rate is significantly reduced, and maintenance costs are drastically lowered.

[0041] Meanwhile, the mineral processing reagent system has been repeatedly researched and adjusted, with the dosage of each reagent precisely matched to the needs of different flotation stages, eliminating waste caused by overuse. With the dual benefits of achieving high tungsten-tin recovery rates and high-grade concentrate production, the company's product quality has improved, its market competitiveness has increased, and it can obtain better prices and orders. Steady production growth brings economies of scale, faster capital recovery, and expanded profit margins, helping the company seize opportunities in market competition and solidify its development foundation.

[0042] 3. Good environmental benefits: Traditional mineral processing techniques have limited resource recovery rates, resulting in a large amount of tungsten and tin metal residues in tailings. Long-term stockpiling or improper disposal of these tailings can easily trigger a chain reaction of environmental pollution: heavy metals are washed into the soil by rainwater, causing soil compaction, nutrient loss, and damage to the soil's ecological structure; they flow into surrounding water bodies, causing water turbidity, exacerbating eutrophication, threatening the survival and reproduction of aquatic organisms, and even posing a potential threat to human health through accumulation in the food chain.

[0043] This method, with its excellent resource recovery efficiency, significantly reduces the residual tungsten and tin metals in tailings, mitigating pollution risks at the source. The simplified tailings composition reduces both the difficulty and cost of subsequent disposal, aligning with the development direction of green mining. This not only demonstrates the company's environmental responsibility, fostering a positive corporate image and garnering policy support and social praise, but also effectively protects the integrity of the local ecological environment, maintains regional biodiversity, creates a healthy living space for surrounding residents, and achieves harmonious coexistence between the company and the ecological environment.

[0044] 4. High Applicability: Global mineral resources are widely distributed, and the characteristics of low-grade, fine-grained tungsten-tin ores in different regions vary significantly due to geological factors, requiring highly universal beneficiation technologies. This method is rooted in extensive practical experience and technological research and development, accurately understanding the common characteristics of such ores and the core points of flotation, and creating a highly universal beneficiation process and parameters.

[0045] Regardless of the ore particle size, the variety of mineral distribution morphology, or the complexity and variability of chemical composition, this method can be flexibly adapted and provide stable output. It provides a mature technical example for the comprehensive recovery and utilization of similar low-grade fine-grained tungsten-tin ores. With its outstanding effectiveness, it has quickly gained recognition and reference within the industry and has great value for promotion and application. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the device in Embodiment 1 of the present invention. Detailed Implementation

[0047] The present invention will now be described in further detail with reference to specific embodiments and the accompanying drawings. It should be emphasized that the following description is merely exemplary and is not intended to limit the scope or application of the present invention.

[0048] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0049] In an embodiment of the present invention, a method for the comprehensive utilization of low-grade fine-grained tungsten-tin particles is provided, using advanced flotation equipment systems and mineral processing reagents.

[0050] The advanced flotation equipment system includes a thickener, a desulfurization roughing flotation column, a desulfurization cleaning flotation column, a tungsten-tin roughing flotation column, a tungsten-tin scavenging flotation column (first stage), a tungsten-tin scavenging flotation column (second stage), a tungsten-tin cleaning flotation column (first stage), a tungsten-tin cleaning flotation column (second stage), and each equipped with a slurry mixing tank.

[0051] The thickener outlet is connected to the feed inlet of the desulfurization roughing agitator; the desulfurization roughing agitator is connected to the feed inlet of the desulfurization roughing flotation column via a pipeline; the concentrate overflow outlet of the desulfurization roughing flotation column is connected to the desulfurization cleaning agitator via a pipeline; the tailings underflow outlet of the desulfurization roughing flotation column is connected to the tungsten-tin roughing agitator via a pipeline; the desulfurization cleaning agitator is connected to the feed inlet of the desulfurization cleaning flotation column via a pipeline; the concentrate overflow outlet of the desulfurization cleaning flotation column is transported to the pump tank via a pipeline. The tailings underflow from the refined flotation column is returned to the desulfurization roughing mixing tank via pipeline; the tungsten-tin roughing mixing tank is connected to the feed inlet of the tungsten-tin roughing flotation column via pipeline; the concentrate overflow from the tungsten-tin roughing flotation column is connected to the first tungsten-tin refined mixing tank via pipeline; the tailings underflow from the tungsten-tin roughing flotation column is connected to the first tungsten-tin scavenging mixing tank via pipeline; the first tungsten-tin scavenging mixing tank is connected to the feed inlet of the first tungsten-tin scavenging flotation column via pipeline; the concentrate overflow from the first tungsten-tin scavenging flotation column is connected to... The tungsten-tin roughing flotation column is connected to the mixing tank via pipeline; the tailings underflow outlet of the tungsten-tin scavenging flotation column 1 is connected to the mixing tank 2 via pipeline; the mixing tank 1 of the tungsten-tin cleaning flotation column is connected to the feed inlet of the tungsten-tin cleaning flotation column 1 via pipeline; the concentrate overflow outlet of the tungsten-tin cleaning flotation column 1 is connected to the mixing tank 2 of the tungsten-tin cleaning flotation column via pipeline; the tailings underflow outlet of the tungsten-tin cleaning flotation column 1 returns to the tungsten-tin roughing flotation column via pipeline; the mixing tank 2 of the tungsten-tin scavenging flotation column is connected to the feed inlet of the tungsten-tin scavenging flotation column 2 via pipeline. The pipelines are connected, with the concentrate overflow outlet of the tungsten-tin scavenging flotation column II connected to the mixing tank of the tungsten-tin scavenging flotation column I via a pipeline, and the tailings underflow outlet of the tungsten-tin scavenging flotation column II being transported to the thickener for thickening and then to the tailings pump pool via a pipeline; the mixing tank of the tungsten-tin refining flotation column II is connected to the feed inlet of the tungsten-tin refining flotation column II via a pipeline, and the concentrate overflow outlet of the tungsten-tin refining flotation column II being transported to the tungsten-tin concentrate pump pool via a pipeline, and the tailings underflow outlet of the tungsten-tin refining flotation column II being returned to the mixing tank of the tungsten-tin refining flotation column I via a pipeline.

[0052] Each of the aforementioned flotation columns—desulfurization roughing flotation column, desulfurization cleaning flotation column, tungsten-tin roughing flotation column, tungsten-tin scavenging flotation column (step 1), tungsten-tin scavenging flotation column (step 2), tungsten-tin cleaning flotation column (step 1), and tungsten-tin cleaning flotation column (step 2)—is equipped with a feed pump that transports the slurry to the corresponding flotation column inlet.

[0053] Each of the aforementioned desulfurization roughing flotation column, desulfurization cleaning flotation column, tungsten-tin roughing flotation column, tungsten-tin scavenging flotation column (first stage), tungsten-tin scavenging flotation column (second stage), tungsten-tin cleaning flotation column (first stage), and tungsten-tin cleaning flotation column (second stage) is equipped with a self-circulating pump.

[0054] The mineral processing reagents include modifiers, collectors, and frothers.

[0055] The aforementioned mineral processing reagents are added to the slurry in specific amounts at each stage of tungsten-tin desulfurization and mixed flotation. The types and amounts of mineral processing reagents added at each stage are as follows:

[0056] Desulfurization stage:

[0057] Copper sulfate is used as a modifier for activation, with a dosage of 50-150 g / t;

[0058] No. 2 oil is used as a foaming agent, with a dosage of 2-30g / t;

[0059] The use of butyl xanthate as a collector for sulfide mineral collection is 30-200 g / t.

[0060] Mixed flotation stage:

[0061] Sodium carbonate is used as a modifier to soften water and adjust the pH of the slurry, with a dosage of 300-900 g / t.

[0062] Lead nitrate was used as a modifier for tungsten-tin activation, with a dosage of 150g-450g / t.

[0063] Acidified water glass is used as a modifier to suppress iron-containing impurities and silicates, with a dosage of 30-300 g / t;

[0064] GY-1, which has excellent tungsten-tin collecting properties and selectivity, is used as a tungsten-tin collector at a dosage of 10-200 g / t, while GY-2 is used as an auxiliary tungsten-tin collector at a dosage of 1-10 g / t.

[0065] A method for the comprehensive utilization of low-grade fine-grained tungsten-tin includes the following steps:

[0066] Step (1): Concentration: Low-grade fine-grained tungsten-tin ore slurry is concentrated using a thickener;

[0067] Step (2): Desulfurization: The concentrated low-grade fine-grained tungsten-tin ore slurry is desulfurized through a desulfurization flotation column; the underflow slurry of thickener 1 is conditioned by adding modifier, collector and frother in the desulfurization roughing mixing tank, and the conditioned slurry is fed into the desulfurization roughing flotation column by a feed pump. The concentrate from the desulfurization roughing flotation column flows into the desulfurization cleaning flotation column, and the tailings from the desulfurization roughing flotation column are fed into the tungsten-tin roughing mixing tank with modifier and collector for slurry conditioning, and then fed into the tungsten-tin roughing flotation column by a feed pump.

[0068] Step (3): Mixed flotation: After desulfurization, the low-grade fine-grained tungsten-tin ore slurry undergoes mixed flotation of tin and tungsten through each flotation column; the concentrate from the tungsten-tin rougher flotation column flows into the tungsten-tin cleaner first stirring tank, where a modifier is added for slurry conditioning, and then fed into the tungsten-tin cleaner first flotation column via a feed pump; the tailings from the tungsten-tin rougher flotation column are fed into the tungsten-tin scavenger first stirring tank, where modifiers and collectors are added for slurry conditioning, and then fed into the tungsten-tin scavenger first flotation column via a feed pump; the concentrate from the tungsten-tin cleaner first flotation column flows into the tungsten-tin cleaner second stirring tank, where a collector is added for slurry conditioning, and then fed into the tungsten-tin cleaner second flotation column via a feed pump; the tailings from the tungsten-tin cleaner first flotation column are returned to the tungsten-tin rougher flotation column. The process involves selecting a mixing tank to achieve a closed-loop circulation. The concentrate from the first scavenging flotation column of tungsten-tin is returned to the roughing mixing tank of tungsten-tin, while the tailings from the first scavenging flotation column are fed into the second scavenging flotation column of tungsten-tin with collectors for slurry preparation, and then fed into the second scavenging flotation column of tungsten-tin via a feed pump. The concentrate from the second scavenging flotation column of tungsten-tin is returned to the first scavenging flotation tank of tungsten-tin, while the tailings from the second scavenging flotation column of tungsten-tin enter the thickener and then flow into the tailings pump pool for pumping away. The concentrate from the second scavenging flotation column of tungsten-tin concentrate flows into the tungsten-tin concentrate pump pool for pumping away, while the tailings from the second scavenging flotation column of tungsten-tin concentrate return to the first scavenging flotation tank of tungsten-tin concentrate, thus achieving a closed-loop circulation and producing a mixed tungsten-tin concentrate.

[0069] To make the present invention more fully disclosed, more specific embodiments are described below.

[0070] Example 1

[0071] Step 1: The low-grade, fine-grained tungsten-tin ore slurry is concentrated using thickener 1. The slurry concentration is 30%, with tungsten-tin grades of WO3 (0.20%-0.40%) and Sn (0.10%-0.30%), and the particle size is mainly concentrated in the -0.025mm range.

[0072] Step 2: The concentrated low-grade fine-particle tungsten-tin ore slurry is desulfurized through desulfurization flotation column 4. The underflow slurry from the thickener is fed into the desulfurization roughing flotation mixing tank 2, where 100g / t of copper sulfate, 150g / t of butyl xanthate, and 20g / t of No. 2 oil are added for conditioning. The slurry after the reagents are added is then fed into the desulfurization roughing flotation column 4 by a feed pump. The concentrate from the desulfurization roughing flotation column 4 flows into the desulfurization cleaning flotation column 3. The tailings from the desulfurization roughing flotation column 4 are fed into the tungsten-tin roughing flotation mixing tank 12, where 600g / t of sodium carbonate, 300g / t of lead nitrate, 120g / t of GY-1, and 6g / t of GY-2 are added for conditioning. The slurry is then fed into the tungsten-tin roughing flotation column 5 by a feed pump.

[0073] Step 3: After desulfurization, the low-grade fine-grained tungsten-tin ore slurry is mixed and floated through various flotation columns. The concentrate from the tungsten-tin rougher flotation column 5 flows into the tungsten-tin concentrate first-stage mixing tank 14, where 20 g / t of GY-1 is added for slurry conditioning, and then fed into the tungsten-tin concentrate first-stage flotation column 7 via a feed pump. The tailings from the tungsten-tin rougher flotation column 5 are fed into the tungsten-tin scavenger flotation first-stage mixing tank 13, where 60 g / t of GY-1 and 300 g / t of acidified water glass are added for slurry conditioning, and then fed into the tungsten-tin scavenger flotation first-stage flotation column 6 via a feed pump. The concentrate from the tungsten-tin concentrate first-stage flotation column 7 flows into the tungsten-tin concentrate second-stage mixing tank 16, where 10 g / t of GY-1 and 120 g / t of acidified water glass are added for slurry conditioning, and then fed into the tungsten-tin concentrate second-stage flotation column 9 via a feed pump. The tailings from the tungsten-tin concentrate first-stage flotation column 7 are returned to the tungsten-tin concentrate first-stage flotation column 9. The tungsten-tin roughing stirring tank 12 achieves closed-loop circulation. The concentrate from the first tungsten-tin scavenging flotation column 6 is returned to the tungsten-tin roughing stirring tank 12, and the tailings from the first tungsten-tin scavenging flotation column 6 are fed into the second tungsten-tin scavenging stirring tank 15. GY-1 is added at a rate of 30 g / t for slurry preparation, and the slurry is then fed into the second tungsten-tin scavenging flotation column 8 via a feed pump. The concentrate from the second tungsten-tin scavenging flotation column 8 is returned to the first tungsten-tin scavenging stirring tank 13, and the tailings from the second tungsten-tin scavenging flotation column 8 flow into the tailings pump pool and are pumped away. The concentrate from the second tungsten-tin cleaning flotation column 9 flows into the tungsten-tin concentrate pump pool and is pumped away. The tailings from the second tungsten-tin cleaning flotation column 9 are returned to the first tungsten-tin cleaning stirring tank 14, achieving closed-loop circulation and producing a mixed tungsten-tin concentrate. (See schematic diagrams of the various devices.) Figure 1 .

[0074] Example 2

[0075] Step (1) in Example 1 is adjusted so that the concentration of the low-grade tungsten-tin ore slurry after thickening by thickener 1 is 50%. The remaining steps remain unchanged, and a tungsten-tin mixed concentrate is produced.

[0076] Example 3

[0077] Step (2) in Example 1 is modified by adding 120g / t of copper sulfate, 160g / t of butyl xanthate, and 30g / t of No. 2 oil to the desulfurization roughing mixing tank 2 for slurry preparation. The remaining steps remain unchanged, and tungsten-tin mixed concentrate is produced.

[0078] Example 4

[0079] Step (2) in Example 1 is modified by adding 600g / t of sodium carbonate, 300g / t of lead nitrate, 150g / t of GY-1, and 6g / t of GY-2 to the tungsten-tin roughing mixing tank 12 for slurry preparation. The remaining steps remain unchanged, and a tungsten-tin mixed concentrate is produced.

[0080] Example 5

[0081] Step (3) in Example 1 is adjusted as follows: In the first stirring tank 14 of the tungsten-tin beneficiation process, 10 g / t of GY-1 is added for slurry preparation; in the first stirring tank 13 of the tungsten-tin scavenging process, 60 g / t of GY-1 is added for slurry preparation; in the second stirring tank 16 of the tungsten-tin beneficiation process, 5 g / t of GY-1 is added for slurry preparation; and in the second stirring tank 15 of the tungsten-tin scavenging process, 20 g / t of GY-1 is added for slurry preparation. The remaining steps remain unchanged, and a mixed tungsten-tin concentrate is produced.

[0082] The tungsten-tin mixed concentrate products produced in Examples 1-5 were analyzed, and the grades and tungsten-tin recovery rates of the products are shown in Table 1 below:

[0083] Table 1: Grade and Tungsten-Tin Mixed Concentrate Product from Examples 1-5

[0084]

[0085] Analysis of the results of Examples 1-5 clearly and accurately reveals the actual effect of the desulfurization-tin-tungsten mixed flotation process designed for low-grade fine-grained tungsten-tin ore, as well as the application advantages of the new flotation equipment system and mineral processing reagents.

[0086] The raw ore grade was between 0.20%-0.40% WO3 and 0.10%-0.30% Sn, belonging to the typical low-grade ore category. Such ores are difficult to beneficiate, and conventional processes have struggled to achieve ideal enrichment results. However, this process performed exceptionally well. The tungsten-tin mixed concentrates produced in all examples achieved WO3+Sn >24%. In Example 2, adjusting the pulp concentration to 50% increased the concentrate grade to >26.3%, highlighting the crucial role of pulp concentration in the beneficiation process. A suitable pulp concentration facilitates the uniform dispersion of flotation reagents, allowing them to fully contact and react with the ore particles, resulting in the effective liberation and enrichment of more tungsten and tin minerals, thereby improving the concentrate grade. Although the other examples showed variations in reagent dosage and formulation, the concentrate grade remained consistently high, fully validating the reliability of this process in controlling concentrate quality.

[0087] Comparing the tungsten recovery rates of Examples 1-5, the experimental data strongly demonstrate the high efficiency of the process. In Example 1, the tungsten recovery rate reached 76.5%, laying the foundation and indicating that the basic process parameters were set reasonably and effectively, and could capture tungsten from the ore well. Example 5 focused on adjusting the amount of GY-1 in each stirred tank during the mixed flotation stage, thereby increasing the tungsten recovery rate to 77.3%, highlighting the importance of precise formulation of mineral processing reagents. As a key collector, the dosage of GY-1 was adapted to the characteristics of tungsten-tin minerals at different flotation stages, and it combined precisely and efficiently with the mineral surface, reducing tungsten residue in the tailings and enhancing the collection effect. The tungsten recovery rates in the other examples remained stable at ≥76%, demonstrating the robustness and efficiency of the process.

[0088] Looking at the tin recovery rate, the results were also satisfactory. In Example 1, the tin recovery rate was 60.6%, and in subsequent examples, when adjusting the process parameters, the tin recovery rate remained consistently at ≥59%. For example, in Example 3, adjusting the dosage of reagents in the desulfurization roughing agitator, and in Example 4, fine-tuning the reagent combination in the tungsten-tin roughing agitator, did not significantly reduce the tin recovery effect, indicating that this process is suitable for tin recovery. The various reagents work synergistically in different flotation stages, separating sulfide ores and suppressing impurities, creating a favorable environment for tin flotation and enrichment, and ensuring efficient recovery.

[0089] Overall, these five sets of examples comprehensively verify the scientific validity and advanced nature of this process. The new flotation equipment system has a reasonable layout, efficient stirring and conveying, and a practical self-circulation function, providing hardware support for slurry treatment and mineral separation. The mineral processing reagents are formulated as needed and work closely with the equipment. Together, they overcome the challenges of beneficiating low-grade, fine-grained tungsten-tin ore, providing a feasible example for the beneficiation of similar ores, and have great potential for widespread application, thus promoting efficient resource recovery and sustainable development in the industry.

[0090] Those skilled in the art will recognize that numerous variations are possible with respect to the above description, and therefore the embodiments are merely illustrative of one or more specific implementations.

[0091] Although exemplary embodiments of the invention have been described and illustrated, those skilled in the art will understand that various changes and substitutions can be made thereto without departing from the spirit of the invention. Furthermore, many modifications can be made to adapt specific situations to the doctrine of the invention without departing from the central concepts of the invention described herein. Therefore, the invention is not limited to the specific embodiments disclosed herein, but may include all embodiments and equivalents that fall within the scope of the invention.

Claims

1. A method for the comprehensive utilization of low-grade fine-grained tungsten-tin, characterized in that, Uses advanced flotation equipment systems and mineral processing reagents; The advanced flotation equipment system includes a thickener, a desulfurization roughing flotation column, a desulfurization cleaning flotation column, a tungsten-tin roughing flotation column, a tungsten-tin scavenging flotation column (first stage), a tungsten-tin scavenging flotation column (second stage), a tungsten-tin cleaning flotation column (first stage), a tungsten-tin cleaning flotation column (second stage), and each equipped with a slurry mixing tank. The mineral processing reagents include modifiers, collectors, and frothers; The method includes the following steps: Step (1): Concentration: Low-grade fine-grained tungsten-tin ore slurry is concentrated using a thickener; Step (2): Desulfurization: The concentrated low-grade fine-grained tungsten-tin ore slurry is desulfurized through a desulfurization flotation column; the slurry from the thickener bottom flow is conditioned by adding modifier, collector and frother in the desulfurization roughing mixing tank, and the conditioned slurry is fed into the desulfurization roughing flotation column by a feed pump; the concentrate from the desulfurization roughing flotation column flows into the desulfurization cleaning flotation column; the tailings from the desulfurization roughing flotation column are fed into the tungsten-tin roughing mixing tank, where modifier and collector are added for slurry conditioning, and then fed into the tungsten-tin roughing flotation column by a feed pump. Step (3): Mixed flotation: After desulfurization, the low-grade fine-grained tungsten-tin ore slurry undergoes mixed flotation of tin and tungsten through each flotation column; the concentrate from the tungsten-tin rougher flotation column flows into the mixing tank of the tungsten-tin cleaner first flotation column, where a modifier is added for slurry conditioning, and then fed into the tungsten-tin cleaner first flotation column via a feed pump; the tailings from the tungsten-tin rougher flotation column are fed into the mixing tank of the tungsten-tin scavenger first flotation column, where modifiers and collectors are added for slurry conditioning, and then fed into the tungsten-tin scavenger first flotation column via a feed pump; the concentrate from the tungsten-tin cleaner first flotation column flows into the mixing tank of the tungsten-tin cleaner second flotation column, where a collector is added for slurry conditioning, and then fed into the tungsten-tin cleaner second flotation column via a feed pump; the tailings from the tungsten-tin cleaner first flotation column are returned to the tungsten-tin rougher flotation column. The mixing tank achieves a closed-loop circulation. The concentrate from the first scavenging flotation column of tungsten-tin is returned to the tungsten-tin roughing mixing tank, and the tailings from the first scavenging flotation column are fed into the second scavenging flotation tank of tungsten-tin, where collectors are added to adjust the slurry, and then fed into the second scavenging flotation column of tungsten-tin via a feed pump. The concentrate from the second scavenging flotation column of tungsten-tin is returned to the first scavenging flotation tank of tungsten-tin, and the tailings from the second scavenging flotation column of tungsten-tin enter the thickener and then flow into the tailings pump pool for pumping away. The concentrate from the second scavenging flotation column of tungsten-tin flows into the tungsten-tin concentrate pump pool for pumping away, and the tailings from the second scavenging flotation column of tungsten-tin return to the first scavenging flotation tank of tungsten-tin, thus achieving a closed-loop circulation and producing a tungsten-tin mixed concentrate.

2. The method for comprehensive utilization of low-grade fine-grained tungsten-tin according to claim 1, characterized in that, In the advanced flotation equipment system, the thickener outlet is connected to the feed inlet of the desulfurization roughing agitator; the desulfurization roughing agitator is connected to the feed inlet of the desulfurization roughing flotation column via a pipeline; the concentrate overflow outlet of the desulfurization roughing flotation column is connected to the desulfurization cleaning agitator via a pipeline; the tailings underflow outlet of the desulfurization roughing flotation column is connected to the tungsten-tin roughing agitator via a pipeline; the desulfurization cleaning agitator is connected to the feed inlet of the desulfurization cleaning flotation column via a pipeline; and the concentrate overflow outlet of the desulfurization cleaning flotation column is connected to... The tailings from the desulfurization and cleaning flotation column are transported to the pump tank via pipelines. The tailings underflow from the desulfurization and cleaning flotation column is returned to the desulfurization roughing mixing tank via pipelines. The tungsten-tin roughing mixing tank is connected to the inlet of the tungsten-tin roughing flotation column via pipelines. The concentrate overflow from the tungsten-tin roughing flotation column is connected to the tungsten-tin cleaning mixing tank via pipelines. The tailings underflow from the tungsten-tin roughing flotation column is connected to the tungsten-tin scavenging mixing tank via pipelines. The tungsten-tin scavenging mixing tank is connected to the inlet of the tungsten-tin scavenging flotation column via pipelines. The concentrate overflow outlet of the flotation column is connected to the roughing mixing tank of the tungsten-tin flotation column via a pipeline; the tailings underflow outlet of the tungsten-tin scavenging flotation column 1 is connected to the tungsten-tin scavenging mixing tank 2 via a pipeline; the tungsten-tin cleaning mixing tank 1 is connected to the feed inlet of the tungsten-tin cleaning flotation column 1 via a pipeline; the concentrate overflow outlet of the tungsten-tin cleaning flotation column 1 is connected to the tungsten-tin cleaning mixing tank 2 via a pipeline; the tailings underflow outlet of the tungsten-tin cleaning flotation column 1 returns to the roughing mixing tank of the tungsten-tin flotation column 1 via a pipeline; the tungsten-tin scavenging mixing tank 2 is connected to the feed inlet of the tungsten-tin scavenging flotation column 2 via a pipeline. The feed inlets are connected via pipelines. The concentrate overflow outlet of the tungsten-tin scavenging flotation column 2 is connected to the mixing tank of the tungsten-tin scavenging flotation column 1 via pipelines. The tailings underflow outlet of the tungsten-tin scavenging flotation column 2 is transported to the thickener for thickening and then to the tailings pump pool via pipelines. The mixing tank of the tungsten-tin beneficiation column 2 is connected to the feed inlet of the tungsten-tin beneficiation column 2 via pipelines. The concentrate overflow outlet of the tungsten-tin beneficiation column 2 is transported to the tungsten-tin concentrate pump pool via pipelines. The tailings underflow outlet of the tungsten-tin beneficiation column 2 is returned to the mixing tank of the tungsten-tin beneficiation column 1 via pipelines.

3. The method for comprehensive utilization of low-grade fine-grained tungsten-tin according to claim 1, characterized in that, Each of the aforementioned flotation columns—desulfurization roughing flotation column, desulfurization cleaning flotation column, tungsten-tin roughing flotation column, tungsten-tin scavenging flotation column (step 1), tungsten-tin scavenging flotation column (step 2), tungsten-tin cleaning flotation column (step 1), and tungsten-tin cleaning flotation column (step 2)—is equipped with a feed pump that transports the slurry to the corresponding flotation column inlet.

4. The method for comprehensive utilization of low-grade fine-grained tungsten-tin according to claim 1, characterized in that, Each of the aforementioned desulfurization roughing flotation column, desulfurization cleaning flotation column, tungsten-tin roughing flotation column, tungsten-tin scavenging flotation column (first stage), tungsten-tin scavenging flotation column (second stage), tungsten-tin cleaning flotation column (first stage), and tungsten-tin cleaning flotation column (second stage) is equipped with a self-circulating pump.

5. The method for comprehensive utilization of low-grade fine-grained tungsten-tin according to claim 1, characterized in that, The aforementioned mineral processing reagents are added to the slurry in specific amounts at each stage of tungsten-tin desulfurization and tin-tungsten mixed flotation. The types and amounts of mineral processing reagents added during the desulfurization stage are as follows: Copper sulfate is used as a modifier for activation, with a dosage of 50-150 g / t; No. 2 oil is used as a foaming agent, with a dosage of 2-30g / t; The use of butyl xanthate as a collector for sulfide mineral collection is 30-200 g / t.

6. The method for comprehensive utilization of low-grade fine-grained tungsten-tin according to claim 1, characterized in that, The aforementioned mineral processing reagents are added to the slurry in specific amounts at each stage of tungsten-tin desulfurization and tin-tungsten mixed flotation. The types and amounts of mineral processing reagents added during the mixed flotation stage are as follows: Sodium carbonate is used as a modifier to soften water and adjust the pH of the slurry, with a dosage of 300-900 g / t. Lead nitrate was used as a modifier for tungsten-tin activation, with a dosage of 150-450 g / t. Acidified water glass is used as a modifier to suppress iron-containing impurities and silicates, with a dosage of 30-300 g / t; GY-1, which has excellent tungsten-tin collecting properties and selectivity, is used as a tungsten-tin collector at a dosage of 10-200 g / t, while GY-2 is used as an auxiliary tungsten-tin collector at a dosage of 1-10 g / t.

7. The method for comprehensive utilization of low-grade fine-grained tungsten-tin according to claim 1, characterized in that, Step (1) Control the concentration of the concentrated slurry to 30%-50%.

8. A method for the comprehensive utilization of low-grade fine-grained tungsten-tin according to claim 1, characterized in that, Step (1) control the tungsten and tin content of the concentrated slurry to be WO3 0.20%-0.40% and Sn 0.10%-0.30%, with the particle size range concentrated in 0.005-0.15mm.

9. A tungsten-tin mixed concentrate prepared by the method according to any one of claims 1-8.

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