Cassiterite collecting agent and flotation method of sulfur-containing micro-fine particle cassiterite fine silt

Abstract

The invention provides a cassiterite collecting agent and a flotation method of sulfur-containing micro-fine particle cassiterite fine silt. The cassiterite collecting agent is formed by mixing benzohydroxamic acid and sodium dextran sulfate. Or the cassiterite collecting agent is a carboxymethyl chitosan-catechol polymer. The combination of a cassiterite collecting agent carboxymethyl chitosan-catechol polymer or benzohydroxamic acid and dextran sulfate sodium has a unique dual-action mechanism of'strong anchoring-bridging flocculation '. Benzohydroxamic acid and dextran sulfate sodium or catechol groups form super-strong coordination with Sn < 4 + > on the cassiterite surface, so that strong anchoring is realized; and a plurality of micro-fine particle cassiterite can be simultaneously adsorbed by a macromolecular long chain to form an easily floated aggregate, so that bridging flocculation is realized. By means of the cassiterite collecting agent, the capturing capacity of 20-micron ultra-fine cassiterite can be remarkably improved. Compared with conventional benzohydroxamic acid, the recovery rate of the micro-fine particle cassiterite is increased by 8-15%, and maximization of resource utilization is achieved.

Description

Technical Field

[0001] This application relates to the technical field of mineral processing, and in particular to a cassiterite collector and a flotation method for sulfur-containing fine cassiterite mud. Background Technology

[0002] Tin, as an important strategic metal, plays an irreplaceable role in many fields such as electronics, aerospace, metallurgy, and chemicals. The stable supply and efficient utilization of its resources are crucial to national industrial development and economic security.

[0003] Currently, the industry mainly uses a combined process of gravity separation and flotation for the recycling of cassiterite.

[0004] Although existing processes are relatively effective in processing coarse cassiterite, they still suffer from low recovery rates for fine cassiterite, especially particles smaller than 20 micrometers. Summary of the Invention

[0005] To address the problems existing in the background technology, this application provides a cassiterite collector and a flotation method for sulfur-containing fine cassiterite mud. The cassiterite collector is provided as a mixture of benzoic acid and sodium dextran sulfate; or, the cassiterite collector is a carboxymethyl chitosan-catechol polymer. The cassiterite collector, a combination of carboxymethyl chitosan-catechol polymer or benzoic acid and sodium dextran sulfate, possesses a unique dual mechanism of "strong anchoring-bridging flocculation." Its benzoic acid and sodium dextran sulfate or catechol groups interact with the Sn surface of cassiterite. 4+ It forms super-strong coordination, achieving powerful anchoring; its long polymer chains can simultaneously adsorb multiple fine cassiterite particles, forming easily floatable agglomerates and achieving bridging flocculation. The cassiterite collector can significantly improve the capture capacity of 20-micron, especially 10-micron, ultrafine cassiterite particles. Compared with conventional benzohydroxyxamic acid, it can further increase the recovery rate of fine-grained cassiterite by 8-15%, maximizing resource utilization.

[0006] The specific details of the invention are as follows: In a first aspect, this application provides a cassiterite collector, wherein the cassiterite collector is a mixture of benzohydroxyoxime acid and sodium dextran sulfate; or, the cassiterite collector is a carboxymethyl chitosan-catechol polymer.

[0007] Optionally, the mass ratio of sodium dextran sulfate to benzohydroxyxamic acid is 1:(3-4).

[0008] Secondly, this application provides a flotation method for sulfur-containing fine-particle cassiterite mud, the flotation method comprising the following steps: S1. Grind the gravity separation tailings of the sulfur-containing fine cassiterite mud and mix it with water to obtain a slurry; add the cassiterite collector, dispersant and frother as described in any one of claims 1-2 to the slurry and place it in a high-pressure jet flotation machine for roughing to obtain roughing concentrate and roughing tailings. S2. Continue to add the cassiterite collector and / or the frother to the roughing tailings, place it in the high-pressure jet flotation machine for multiple scavenging, and return the scavenged concentrate obtained from each scavenging to the upper-level scavenging operation for cyclic scavenging. After multiple scavenging operations, the final scavenged tailings are obtained. S3. The rough concentrate is placed in the high-pressure jet flotation machine for multiple blank cleaning processes. The cleaned concentrate obtained from each cleaning process is returned to the upper-level cleaning operation for cyclic cleaning. The tin-containing concentrate and sulfur-containing tin middlings obtained after multiple cleaning processes are combined and processed to obtain tin concentrate.

[0009] Optionally, in steps S1 to S3, the circulating pressure of the high-pressure jet flotation machine is 0.15 to 0.22 MPa, and the thickness of the foam layer is 5 to 15 cm.

[0010] Optionally, in step S1, the amount of cassiterite collector added is 600-1000 g / t based on the ore after grinding; and / or, The amount of the dispersant added is 800~1000 g / t; and / or, The amount of foaming agent added is 10~60g / t.

[0011] Optionally, in step S2, the amount of cassiterite collector added is 60-800 g / t, based on the amount of ore in the roughing tailings; and / or, The amount of foaming agent added is 10~50g / t.

[0012] Optionally, in step S1, before adding the cassiterite collector to the slurry, the flotation method further includes: The slurry is passed through a hydrocyclone under a pressure of 0.05~0.15MPa to remove particles smaller than 0.019mm from the slurry.

[0013] Optionally, the tin content in the sulfur-containing fine cassiterite mud is 0.6%~0.9% and the sulfur content is 5.9%~6.9%, and the proportion of -0.074mm particles in the slurry is 70%~85%.

[0014] Optionally, the dispersant comprises one or more of sodium pyrophosphate, sodium hexametaphosphate, sodium dodecylbenzenesulfonate, sodium citrate, sodium carboxymethyl cellulose, and polyethylene glycol; and / or, The foaming agent includes one or more of pine oil, camphor oil, methyl isobutyl alcohol, and sodium dodecyl sulfate.

[0015] Optionally, the tin recovery rate is 85% to 96%, and the tin loss rate in the gravity separation tailings is less than or equal to 1.9%.

[0016] Compared with the prior art, this application has the following advantages: This application provides a cassiterite collector and a flotation method for sulfur-containing fine cassiterite mud. The cassiterite collector is a mixture of benzoic acid and sodium dextran sulfate; or, the cassiterite collector is a carboxymethyl chitosan-catechol polymer. The cassiterite collector, a combination of carboxymethyl chitosan-catechol polymer or benzoic acid and sodium dextran sulfate, possesses a unique dual mechanism of "strong anchoring-bridging flocculation." Its benzoic acid and sodium dextran sulfate or catechol groups interact with the Sn surface of cassiterite. 4+ It forms a super-strong coordination, achieving powerful anchoring; its long polymer chains can simultaneously adsorb multiple fine cassiterite particles, forming easily floatable agglomerates and achieving bridging flocculation. The cassiterite collector can significantly improve the capture capacity for 20-micron, especially 10-micron, ultra-fine cassiterite particles. Compared with conventional benzohydroxyxamic acid, it can further increase the recovery rate of fine-grained cassiterite by 8-15%, thereby stably controlling the tin loss rate in the final tailings to below 0.04%, far lower than the industry average (usually >1.5%), maximizing resource utilization.

[0017] In addition, the cassiterite collector uses natural, biodegradable chitosan as its backbone. Its own and modified products have far lower environmental toxicity than traditional small molecule collectors such as hydroxyxamic acid and arsenic. While achieving efficient recovery, it significantly reduces the environmental impact of the mineral processing process, which meets the requirements of green mines and sustainable development, and has significant social and environmental benefits. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic flow diagram of a flotation method for sulfur-containing fine cassiterite mud provided in an embodiment of this application is shown. Figure 2 A process flow diagram of the flotation method for sulfur-containing fine cassiterite mud provided in the embodiments of this application is shown; Figure 3 A flow field simulation diagram provided in an embodiment of this application is shown. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its application or use. Based on the embodiments of this application, any product that is the same as or similar to this application, derived by anyone under the guidance of this application or by combining features of this application with other prior art, falls within the protection scope of this application. Furthermore, all other embodiments obtained by those skilled in the art without inventive effort are within the protection scope of this application.

[0021] Specific experimental steps or conditions are not specified in the embodiments; they can be performed according to the conventional experimental steps or conditions described in the prior art. Reagents and other instruments used, unless otherwise specified, are all commercially available conventional reagent products. Furthermore, the accompanying drawings are merely illustrative diagrams of the embodiments of this application and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore, repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities.

[0022] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of this application specification.

[0023] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0024] Tin, as an important strategic metal, plays an irreplaceable role in numerous fields such as electronics, aerospace, metallurgy, and chemicals. The stable supply and efficient utilization of its resources are crucial to national industrial development and economic security. With the acceleration of global industrialization, the demand for tin resources continues to grow. However, high-grade, easily beneficiated rich ores have seen a sharp decline in reserves after long-term large-scale mining, leading to a gradual deterioration in resource endowment. Against this backdrop, the development and utilization of difficult-to-process tin ores, such as lean ores, fine-grained ores, and complex polymetallic symbiotic ores, has become key to alleviating the supply-demand imbalance of tin resources and ensuring the sustainable development of the tin industry. Among these, the research and development of efficient recovery technologies for cassiterite, as the main tin-bearing mineral, has received widespread attention within the industry. Currently, the industry primarily employs a combined gravity separation and flotation process for cassiterite recovery. Gravity separation, with its advantages of low cost and simple operation, is widely used in the recovery of coarse-grained cassiterite, effectively enriching some of the coarse-grained cassiterite. However, for fine and micro-fine-grained cassiterite that is difficult to recover by gravity separation, flotation has become the main recovery method. By adding collectors, frothers, and modifiers to the flotation system, the surface physicochemical properties of cassiterite, gangue minerals, and associated sulfide minerals are altered, allowing cassiterite to adhere to the surface of air bubbles and float with them, thus achieving separation from other minerals. Currently, the combined gravity separation-flotation process has been widely adopted in numerous tin ore beneficiation plants both domestically and internationally, becoming the mainstream process route for cassiterite recovery.

[0025] Although the gravity-flotation combined process plays a crucial role in cassiterite recovery, it still faces numerous technical challenges and shortcomings in the recovery of fine-grained cassiterite (especially cassiterite particles smaller than 20 micrometers). On the one hand, fine-grained cassiterite has a large specific surface area and high surface energy, making it prone to agglomeration during flotation. This hinders the effective adsorption of collectors on its surface. Furthermore, the small mass of fine-grained cassiterite significantly increases its likelihood of being lost with the water flow in the flotation system, resulting in poor collection efficiency and excessive reagent consumption. Ultimately, the flotation recovery rate of fine-grained cassiterite is generally below 45%, leading to the loss of a large amount of valuable metal resources in tailings. On the other hand, cassiterite is often associated with metal sulfide ores. During flotation, sulfide ores compete with cassiterite for collectors, and some... The floatability of sulfide ores is similar to that of fine-grained cassiterite, further exacerbating the difficulty of separating fine-grained cassiterite from sulfide ores. In addition, the stirring intensity, bubble generation and distribution characteristics of existing conventional mechanical agitation flotation machines are insufficient to meet the flotation requirements of fine-grained cassiterite, and cannot provide sufficient and suitable bubble adhesion conditions for fine-grained cassiterite, resulting in a significantly insufficient recovery efficiency of fine-grained cassiterite. These problems seriously restrict the efficient utilization of fine-grained cassiterite resources and also create a prominent contradiction between existing separation technologies and the actual needs of current fine-grained mineral recovery.

[0026] In view of the problem of low recovery rate of fine cassiterite in related technologies, this application provides a cassiterite collector, wherein the cassiterite collector is a mixture of benzohydroxyxamic acid and sodium dextran sulfate; or, the cassiterite collector is a carboxymethyl chitosan-catechol polymer.

[0027] It should be noted that the preparation process of the carboxymethyl chitosan-catechol polymer is as follows: (1) Activation: Dissolve 2.0 g of carboxymethyl chitosan in 100 mL of 2-morpholine ethanesulfonic acid buffer solution (pH 5.5) and mix well. Then add 1.2 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and 0.7 g of N-hydroxysuccinimide (NHS) and stir at room temperature in the dark for 30 minutes to activate the carboxyl group in carboxymethyl chitosan into a chalky ester intermediate that is more easily reacted with amines, thus forming a carboxymethyl chitosan solution.

[0028] (2) Grafting reaction: Dissolve 2.0 g of dopamine hydrochloride in 20 mL of phosphate buffer solution (pH 7.4) and mix well to form a dopamine solution. Slowly add the dopamine solution to the activated carboxymethyl chitosan solution. Place the reaction system under nitrogen or argon protection and stir at room temperature in the dark for 24 hours.

[0029] (3) Purification: After the reaction is completed, the mixture is transferred to a dialysis bag and dialyzed with dilute hydrochloric acid (pH ~4) for 2 days, and then dialyzed with deionized water for 3 days. The water is changed 3 to 4 times a day to completely remove unreacted small molecule byproducts and salts.

[0030] (4) Product: The solution in the dialysis bag was freeze-dried to obtain a brown sponge-like solid, and the final product was obtained: carboxymethyl chitosan-catechol polymer.

[0031] It should be noted that the mechanism by which benzohydroxyxamic acid and sodium dextran sulfate synergistically promote cassiterite flotation is as follows: benzohydroxyxamic acid, as the main collector, specifically chelates with tin ions on the surface of cassiterite through its hydroxamic acid groups, forming a stable five-membered ring hydrophobic film; while sodium dextran sulfate can not only specifically chelate with tin, but also act as a highly efficient inhibitor, selectively adsorbing onto the surface of gangue minerals to make them hydrophilic and inhibit their activity. At the same time, it can also help enhance the adsorption strength and hydrophobic effect of benzohydroxyxamic acid on the surface of cassiterite through "bridging" and other effects. The synergistic effect of the two ultimately achieves efficient and highly selective collection of cassiterite.

[0032] In this embodiment, the cassiterite collector is a mixture of benzohydroxyxamic acid and sodium dextran sulfate; or, the cassiterite collector is a carboxymethyl chitosan-catechol polymer. The cassiterite collector, a combination of carboxymethyl chitosan-catechol polymer or benzohydroxyxamic acid and sodium dextran sulfate, possesses a unique dual mechanism of "strong anchoring-bridging flocculation." Its benzohydroxyxamic acid and sodium dextran sulfate or catechol groups interact with the Sn surface of cassiterite. 4+It forms a super-strong coordination, achieving powerful anchoring; its long polymer chains can simultaneously adsorb multiple fine cassiterite particles, forming easily floatable agglomerates and achieving bridging flocculation. The cassiterite collector can significantly improve the capture capacity for 20-micron, especially 10-micron, ultra-fine cassiterite particles. Compared with conventional benzohydroxyxamic acid, it can further increase the recovery rate of fine-grained cassiterite by 8-15%, thereby stably controlling the tin loss rate in the final tailings to below 0.04%, far lower than the industry average (usually >1.5%), maximizing resource utilization.

[0033] In addition, the cassiterite collector uses natural, biodegradable chitosan as its backbone. Its own and modified products have far lower environmental toxicity than traditional small molecule collectors such as hydroxyxamic acid and arsenic. While achieving efficient recovery, it significantly reduces the environmental impact of the mineral processing process, which meets the requirements of green mines and sustainable development, and has significant social and environmental benefits.

[0034] In some embodiments, the mass ratio of sodium dextran sulfate to benzohydroxyxamic acid is 1:(3-4).

[0035] It should be noted that the mass ratio of sodium dextran sulfate to benzohydroxyxamic acid is 1:(3-4). For example, the mass ratio of benzohydroxyxamic acid to sodium dextran sulfate is one or any two of the following: 1:3, 1:3.1, 1:3.2, 1:3.3, 1:3.4, 1:3.5, 1:3.6, 1:3.7, 1:3.8, 1:3.9, 1:4.

[0036] In this embodiment, the mass ratio of sodium dextran sulfate to benzohydroxyxamic acid is 1:(3-4), which can further increase the recovery rate of fine-grained cassiterite by 8-15%, achieving a balance between recovery rate and grade.

[0037] Secondly, this application provides a flotation method for sulfur-containing fine-particle cassiterite mud, such as... Figure 1-2 As shown, the flotation method includes the following steps: S1. Grind the gravity separation tailings of the sulfur-containing fine cassiterite mud and mix it with water to obtain a slurry; add the cassiterite collector, dispersant and frother to the slurry and place it in a high-pressure jet flotation machine for roughing to obtain roughing concentrate and roughing tailings. S2. Continue to add the cassiterite collector and / or the frother to the roughing tailings, place it in the high-pressure jet flotation machine for multiple scavenging, and return the scavenged concentrate obtained from each scavenging to the upper-level scavenging operation for cyclic scavenging. After multiple scavenging operations, the final scavenged tailings are obtained. S3. The rough concentrate is placed in the high-pressure jet flotation machine for multiple blank cleaning processes. The cleaned concentrate obtained from each cleaning process is returned to the upper-level cleaning operation for cyclic cleaning. The tin-containing concentrate and sulfur-containing tin middlings obtained after multiple cleaning processes are combined and processed to obtain tin concentrate.

[0038] It should be noted that in step S2, the number of sweeps is 2 to 5 times. For example, 2, 3, 4, or 5 sweeps can be performed. Multiple cyclic sweeps are beneficial for closed-loop recovery, do not waste trace amounts of cassiterite, and remove sulfide minerals at the same time.

[0039] It should be noted that in step S3, the number of blank selections is 2 to 5 times. For example, 2, 3, 4, or 5 blank selections can be performed. Multiple cyclic blank selections are beneficial for closed-loop purification and prevent the loss of effective tin.

[0040] In this embodiment, the cassiterite collector can significantly improve the capture ability of cassiterite particles of 20 micrometers, especially 10 micrometers.

[0041] Furthermore, by employing a process of "one roughing, multiple scavenging, and multiple cleaning," the impact of middlings circulation on concentrate quality during flotation can be effectively reduced, reagent usage can be decreased, the process flow can be shortened, and the circulation of fine and micro-fine tin particles during flotation can be resolved.

[0042] Furthermore, the strong turbulence and shear force generated by the high-pressure jet flotation machine not only provide sufficient kinetic energy and collision probability for fine particles, but also effectively break the adsorption energy barrier of polymers on the surface of mineral particles, allowing them to spread rapidly and uniformly on the cassiterite surface. At the same time, the strong shear force helps to disperse excessively large agglomerates caused by polymers, forming ideal flotation agglomerates of moderate size and good hydrophobicity, thus avoiding the decrease in selectivity and equipment blockage caused by excessive agglomeration.

[0043] High-pressure jet flotation machine and specific polymeric cassiterite collector promote and optimize each other, forming the "best partner" for the recovery of fine-grained cassiterite. The recovery rate of fine-grained cassiterite is increased by 8-15%, thereby stabilizing the tin loss rate in the final tailings below 0.04%, significantly reducing tailings loss. Its comprehensive separation efficiency far exceeds the simple sum of the effects of the two.

[0044] In some embodiments, in steps S1 to S3, the circulating pressure of the high-pressure jet flotation machine is 0.15 to 0.22 MPa, and the thickness of the foam layer is 5 to 15 cm.

[0045] It should be noted that the circulation pressure of the high-pressure jet flotation machine is 0.15~0.22MPa. For example, the circulation pressure of the high-pressure jet flotation machine can be one or any two of the following: 0.15 MPa, 0.16 MPa, 0.17 MPa, 0.18 MPa, 0.19 MPa, 0.20 MPa, 0.21 MPa, and 0.22 MPa.

[0046] It should be noted that the thickness of the foam layer in the high-pressure jet flotation machine is 5~15cm. For example, the thickness of the foam layer in the high-pressure jet flotation machine can be one or any two of the following values: 5 cm, 6 cm, 7 cm, 8 cm, 9 cm, 10 cm, 11 cm, 12 cm, 13 cm, 14 cm, and 15 cm.

[0047] In this embodiment, the circulating pressure of the high-pressure jet flotation machine is 0.15~0.22MPa, which is a prerequisite for generating qualified bubbles, and the foam layer thickness is 5~15cm, which is a guarantee for achieving efficient separation. With the synergistic effect of the two, the whole process optimization can be achieved, which includes small and uniform bubbles, efficient adhesion of cassiterite, stable foam separation, and high-quality and high-yield concentrate. It is especially suitable for the flotation of cassiterite with a particle size of -0.074mm, and the recovery rate is 8~15% higher than that of traditional mechanical flotation machines.

[0048] In some embodiments, in step S1, the amount of cassiterite collector added is 600-1000 g / t based on the ore after grinding; and / or, The amount of the dispersant added is 800~1000 g / t; and / or, The amount of foaming agent added is 10~60g / t.

[0049] It should be noted that the amount of cassiterite collector added is 600~1000 g / t. For example, the amount of cassiterite collector added can be one or any two of the following values: 600 g / t, 650 g / t, 700 g / t, 750 g / t, 800 g / t, 850 g / t, 900 g / t, 950 g / t, 1000 g / t.

[0050] It should be noted that the amount of dispersant added is 800~1000 g / t. For example, the amount of dispersant added is one or any two of the following: 800 g / t, 820 g / t, 840 g / t, 850 g / t, 880 g / t, 900 g / t, 920 g / t, 950 g / t, 970 g / t, 990 g / t, and 1000 g / t.

[0051] It should be noted that the amount of foaming agent added is 10~60 g / t. For example, the amount of foaming agent added is one or any two of the following: 10 g / t, 15 g / t, 20 g / t, 25 g / t, 30 g / t, 35 g / t, 40 g / t, 45 g / t, 50 g / t, 55 g / t, and 60 g / t.

[0052] In this embodiment, the amount of cassiterite collector added is 600~1000g / t, which achieves precise adsorption of cassiterite and ensures that fine cassiterite particles are fully hydrophobically collected; the amount of dispersant added is 800~1000g / t, which first "breaks down barriers" to remove interference from fine mud and expose the surface of cassiterite, ensuring the precise action of the collector; the amount of foaming agent added is 10~60g / t, which generates stable bubbles suitable for fine cassiterite particles.

[0053] In summary, sufficient collector ensures recovery, high amount of dispersant eliminates interference, and precise frother provides a carrier. The three work together to achieve the goal of high recovery rate and high grade in the flotation of fine cassiterite.

[0054] In some embodiments, in step S2, the amount of cassiterite collector added is 60-800 g / t, based on the amount of ore in the roughing tailings; and / or, The amount of foaming agent added is 10~50g / t.

[0055] It should be noted that the amount of cassiterite collector added is 60~800 g / t. For example, the amount of cassiterite collector added is one or any two of the following values: 60 g / t, 80 g / t, 100 g / t, 120 g / t, 150 g / t, 180 g / t, 200 g / t, 250 g / t, 300 g / t, 350 g / t, 400 g / t, 500 g / t, 600 g / t, 700 g / t, and 800 g / t.

[0056] It should be noted that the amount of foaming agent added is 10~50 g / t. For example, the amount of foaming agent added is one or any two of the following: 10 g / t, 15 g / t, 20 g / t, 25 g / t, 30 g / t, 35 g / t, 40 g / t, 45 g / t, and 50 g / t.

[0057] In this embodiment, the amount of cassiterite collector added is 60~800g / t, which can accurately track residual cassiterite and maximize the recovery rate; the frother is responsible for carrying sufficient amount of floatation. The two work together to achieve the goal of no waste of tin resources, no excess reagent costs, and no obstruction in subsequent processes, which is the key to improving the overall recovery rate of cassiterite flotation.

[0058] In some embodiments, before adding the cassiterite collector to the slurry in step S1, the flotation method further includes: The slurry is passed through a hydrocyclone under a pressure of 0.05~0.15MPa to remove particles smaller than 0.019mm from the slurry.

[0059] It should be noted that the pressure of the hydrocyclone is 0.05~0.15MPa. For example, the pressure of the hydrocyclone can be one or any two of the following: 0.05 MPa, 0.06 MPa, 0.07 MPa, 0.08 MPa, 0.10 MPa, 0.11 MPa, 0.12 MPa, 0.13 MPa, 0.14 MPa, and 0.15 MPa.

[0060] In this embodiment, particles smaller than 0.019 mm may adsorb onto the mineral surface, hindering the effective binding of minerals and bubbles and reducing flotation efficiency. Removing these fine particles using a hydrocyclone can improve the properties of the slurry, allowing subsequent flotation processes to function better, increasing beneficiation recovery and concentrate grade, reducing ineffective reagent consumption, lowering beneficiation costs, and improving slurry concentration efficiency, which is beneficial for subsequent dewatering and tailings discharge.

[0061] In some embodiments, the tin content in the sulfur-containing fine cassiterite mud is 0.6%~0.9% and the sulfur content is 5.9%~6.9%, and the proportion of -0.074mm particles in the slurry is 70%~85%.

[0062] It should be noted that the tin content in the sulfur-containing fine-grained cassiterite mud is 0.6% to 0.9%. For example, the tin content in the sulfur-containing fine-grained cassiterite mud is one or any two of the following values: 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, and 0.9%.

[0063] It should be noted that the sulfur content in the sulfur-containing fine-grained cassiterite mud is 5.9% to 6.9%. For example, the sulfur content in the sulfur-containing fine-grained cassiterite mud is one or any two of the following values: 5.9%, 6.0%, 6.1%, 6.2%, 6.3%, 6.4%, 6.5%, 6.6%, 6.7%, 6.8%, and 6.9%.

[0064] It should be noted that the proportion of -0.074mm particles in the slurry is 70% to 85%. For example, the proportion of -0.074mm particles in the slurry is one or any two of the following values: 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, and 85%.

[0065] In this embodiment, the gravity separation tailings of sulfur-containing fine cassiterite mud are ground and then mixed. The -0.074mm particle size accounts for 70%~85% of the slurry. The purpose of grinding is to increase the degree of mineral liberation by adjusting the grinding media and grinding time, so that cassiterite and gangue minerals are fully separated, and the coordination bonds between cassiterite and flotation reagents are increased. On the other hand, the high-pressure jet flotation machine increases the exposed surface area between the reagent and cassiterite, increases the surface potential of cassiterite, enhances the interaction between fine and micro-fine cassiterite and flotation reagents, achieves selective adsorption of reagents on the cassiterite surface, and realizes efficient recovery of coarse-fine-micro-fine cassiterite.

[0066] In some embodiments, the dispersant comprises one or more of sodium pyrophosphate, sodium hexametaphosphate, sodium dodecylbenzenesulfonate, sodium citrate, sodium carboxymethyl cellulose, and polyethylene glycol; and / or, The foaming agent includes one or more of pine oil, camphor oil, methyl isobutyl alcohol, and sodium dodecyl sulfate.

[0067] It should be noted that the dispersant used in this application is preferably one or more of sodium pyrophosphate and sodium hexametaphosphate.

[0068] It should be noted that the foaming agent used in this application is preferably one or more of pine oil and camphor oil.

[0069] In this embodiment, the dispersant is selected from one or more of the above-mentioned materials and can break down the interference of fine mud through multiple mechanisms. The foaming agent is selected from one or more of the above-mentioned materials and can provide suitable bubbles through multiple characteristics. The two work together to create an environment in which cassiterite is fully exposed and bubbles are efficiently carried for the flotation of fine cassiterite, which is the reagent guarantee for achieving high recovery rate and high grade.

[0070] In some embodiments, the tin recovery rate is 85% to 96%, and the tin loss rate in the gravity separation tailings is less than or equal to 1.9%.

[0071] It should be noted that the tin recovery rate is 85% to 96%. For example, the tin recovery rate can be one or any two of the following: 85%, 86%, 87%, 88%, 89%, 90%, 92%, 94%, and 96%.

[0072] It should be noted that the tin loss rate in the gravity separation tailings is ≤1.9%. For example, the loss rate can be any point value of 1.9%, 1.8%, 1.6%, 1.5%, 1.4%, 1.3%, 1.2%, 1.1%, or 1.0%, or a range between any two.

[0073] In this embodiment, a recovery rate of 85% to 96% can control the tin loss per ton of raw ore to within 0.02 to 0.075 tons. Even when processing low-grade ore, it can efficiently extract resource value, meeting the development requirements of resource-saving mines and avoiding resource idleness due to insufficient technology. A tin loss rate of less than or equal to 1.9% in gravity separation tailings is the basis for overall high recovery (85% to 96%). Only when coarse cassiterite is lost in small amounts can subsequent flotation focus on fine particle recovery without compensating for coarse particle loss, thus maintaining a stable high overall recovery rate and ultimately achieving a balance between resources, costs, and benefits.

[0074] To enable those skilled in the art to more clearly understand this application, the following embodiments will be used to describe this application in detail.

[0075] The present application will be described in detail below through embodiments.

[0076] Example 1 The flotation method for sulfur-containing fine cassiterite mud is as follows: S1. Grind the gravity separation tailings of sulfur-containing fine cassiterite mud to obtain grinding feed with a particle size of less than 0.074 mm accounting for 75%. The grinding feed contains 0.6% tin and 5.9% sulfur by mass. Mix the grinding feed with water to obtain a slurry. After removing particles smaller than 0.019 mm from the slurry by passing it through a hydrocyclone at a pressure of 0.10 MPa, add 600 g / t of cassiterite collector (cassiterite collector is benzoyl hydroxamic acid and sodium dextran sulfate by mass ratio of 3:1), 800 g / t of dispersant sodium pyrophosphate, and 10 g / t of frother pine oil to the slurry. Then, place it in a high-pressure jet flotation machine at a pressure of 0.15 MPa for roughing. The froth layer thickness is 10 cm to obtain roughing concentrate and roughing tailings. S2. Continue to add the above-mentioned 60g / t cassiterite collector and 10g / t pine oil frother to the roughing tailings, and place it in a high-pressure jet flotation machine for three scavenging processes. The three scavenging processes adopt a stepped pressure control: the pressure of the first scavenging process is 0.15MPa, the pressure of the second scavenging process is 0.20MPa, and the pressure of the third scavenging process is 0.22MPa. The thickness of the froth layer is 5cm. The scavenging concentrate obtained from each scavenging process is returned to the upper-level scavenging process for cyclic scavenging. After three scavenging processes, the final scavenged tailings are obtained. S3. The roughing concentrate is placed in a high-pressure jet flotation machine with a pressure of 0.22MPa for three blank cleaning processes with a froth layer thickness of 5cm. The cleaned concentrate obtained from each cleaning process is returned to the next cleaning process for recycling. The tin-containing concentrate and sulfur-containing tin middlings obtained after the three cleaning processes are combined and processed to obtain tin concentrate.

[0077] Example 2 The difference between Example 2 and Example 1 is as follows: In step S1, the cassiterite collector is adjusted to a mass ratio of 4:1 of benzohydroxyxamic acid and sodium dextran sulfate.

[0078] The other steps and dosages are the same as in Example 1, and tin concentrate is obtained.

[0079] Example 3 The difference between Example 3 and Example 1 is as follows: In step S1, the cassiterite collector is adjusted to a mass ratio of benzohydroxyxamic acid and sodium dextran sulfate of 3.5:1.

[0080] The other steps and dosages are the same as in Example 1, and tin concentrate is obtained.

[0081] Example 4 The difference between Example 4 and Example 1 is as follows: In step S1, the cassiterite collector is changed to a carboxymethyl chitosan-catechol polymer.

[0082] The other steps and dosages are the same as in Example 1, and tin concentrate is obtained.

[0083] Example 5 The difference between Example 5 and Example 1 is: In step S2, the stepped pressure regulation is adjusted as follows: the first scanning pressure is 0.18 MPa, the second scanning pressure is 0.20 MPa, and the third scanning pressure is 0.22 MPa.

[0084] The other steps and dosages are the same as in Example 1, and tin concentrate is obtained.

[0085] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is as follows: In step S1, the slurry is decomposed by a hydrocyclone to remove particles with a particle size adjusted to less than 0.03 mm.

[0086] The other steps and dosages are the same as in Example 1, and tin concentrate is obtained.

[0087] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is as follows: The cassiterite collector in step S2 was changed to benzyl hydroxamic acid.

[0088] The other steps and dosages are the same as in Example 1, and tin concentrate is obtained.

[0089] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is as follows: The dispersant in step S2 is changed to sodium dodecyl sulfate.

[0090] The other steps and dosages are the same as in Example 1, and tin concentrate is obtained.

[0091] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is as follows: In step S2, sodium pyrophosphate, a dispersant, is not added.

[0092] The other steps and dosages are the same as in Example 1, and tin concentrate is obtained.

[0093] The results of tin grade, tin recovery rate, and tin content in the final tailings of the tin concentrate obtained from the various embodiments and comparative examples are shown in Table 1.

[0094] Table 1

[0095] As shown in Table 1, Example 1 exhibited the best performance in terms of tin grade, tin recovery rate, and tin content in tailings, indicating that its process parameters and the mass ratio of the cassiterite collector effectively improved the flotation efficiency of tin slime. In contrast, although the collector ratios in Examples 2-4 were slightly adjusted, the tin grade and recovery rate in the concentrate decreased, while the tin content in the tailings increased, demonstrating that optimizing the collector ratio has a significant impact on the flotation effect.

[0096] In Example 5, by adjusting the stepped scavenging pressure, the concentrate tin grade (6.28%) and recovery rate (93.59%) were close to those of Example 1, indicating that the optimization of stepped pressure control can further improve flotation efficiency.

[0097] Comparative Example 1 showed that the removal of fine particles led to a significant decrease in the tin grade (4.95%) and recovery rate (75.28%) in the concentrate, while the tin content in the tailings (0.31%) increased significantly, indicating that the presence of fine particles has a positive effect on the flotation of tin.

[0098] Comparative Example 2 used a single benzohydroxyxamic acid as a cassiterite collector, with a tin grade of less than 4.21% and a tin recovery rate of less than 70.25%. Moreover, the tin content in the tailings was relatively high. Its effect was far inferior to that of the various examples, proving that the cassiterite collector of this application has a superior improvement effect compared to traditional collectors and has prospects for industrial application.

[0099] Comparative Example 3 used sodium dodecyl sulfate instead of sodium pyrophosphate, and its effect was better than that of Comparative Example 1 but not as good as that of Example 1, indicating that sodium pyrophosphate has an irreplaceable role in the flotation process.

[0100] Comparative Example 4 did not add sodium pyrophosphate. The tin grade and recovery rate of the tin concentrate were comparable to those of Example 2, but the tin content of the tailings was higher, further verifying the importance of sodium pyrophosphate.

[0101] Figure 3The flow field simulation diagram of this application is shown. By comprehensively revealing the complete characteristics of the flow field through the distribution of air pressure, velocity magnitude and a certain volume fraction in the multiphase flow, the pressure cloud map reflects the force and gradient of the fluid, the velocity cloud map intuitively shows the speed and structure of the flow, and the volume fraction cloud map depicts the mixing and distribution state of different fluid components (gas-liquid). The combination of the three provides a key basis for analyzing aerodynamic performance, flow efficiency and multiphase mixing process.

[0102] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0103] For the sake of simplicity, the method embodiments are described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and components involved are not necessarily essential to this application.

[0104] The above provides a detailed description of a cassiterite collector and a flotation method for sulfur-containing fine cassiterite mud provided in this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A cassiterite collector, characterized by, The tin ore collector is mixed by benzohydroxamic acid and sodium dextran sulfate; or the tin ore collector is carboxymethyl chitosan-o-phenol polymer.

2. The cassiterite collector according to claim 1, characterized in that, The mass ratio of the sodium dextran sulfate to the benzohydroxamic acid is 1: (3-4).

3. A flotation process for fine slime containing sulphur-bearing cassiterite, characterised in that, The flotation method comprises the following steps: S1, grinding the gravity separation tailings of the sulfur-containing micro-fine tin ore slime and mixing with water to obtain a slurry; adding the tin ore collector, the dispersant and the frother of any one of claims 1-2 into the slurry, and placing the slurry in a high-pressure jet flotation machine to perform roughing to obtain roughing concentrate and roughing tailings; S2, continuously adding the tin ore collector and / or the frother into the roughing tailings, and placing the roughing tailings in the high-pressure jet flotation machine to perform multiple scavenging, returning the scavenging concentrate obtained each time to the upper scavenging operation for recycling, and obtaining the final scavenging tailings after multiple scavenging; S3, placing the roughing concentrate in the high-pressure jet flotation machine to perform multiple cleanings, returning the cleaning concentrate obtained each time to the upper cleaning operation for recycling, and combining the tin concentrate and the sulfur-containing tin middlings obtained after multiple cleanings to obtain tin concentrate.

4. The flotation method according to claim 3, characterized in that, In steps S1-S3, the circulating pressure of the high-pressure jet flotation machine is 0.15-0.22 MPa, and the thickness of the foam layer is 5-15 cm.

5. The flotation method according to claim 3, characterized in that, In step S1, the addition amount of the tin ore collector is 600-1000 g / t according to the ground ore; and / or, the addition amount of the dispersant is 800-1000 g / t; and / or, the addition amount of the frother is 10-60 g / t.

6. The flotation method according to claim 3, characterized in that, In step S2, the addition amount of the tin ore collector is 60-800 g / t according to the roughing tailings; and / or, the addition amount of the frother is 10-50 g / t.

7. The flotation method according to claim 3, characterized in that, In step S1, before adding the tin ore collector into the slurry, the flotation method further comprises: removing the particles with a particle size less than 0.019 mm in the slurry by a cyclone under a pressure of 0.05-0.15 MPa.

8. The flotation method according to claim 3, characterized in that, The tin grade in the sulfur-containing micro-fine tin ore slime is 0.6%-0.9%, the sulfur grade is 5.9%-6.9%, and the-0.074 mm particle size in the slurry accounts for 70%-85%.

9. The flotation method according to any of claims 3 to 8, characterized in that, The dispersant comprises one or more of sodium pyrophosphate, sodium hexametaphosphate, sodium dodecylbenzenesulfonate, sodium citrate, sodium carboxymethyl cellulose and polyethylene glycol; and / or, The frother comprises one or more of pinol oil, camphor oil, methyl isobutyl carbinol and sodium dodecyl sulfate.

10. The flotation method according to any one of claims 3 to 9, characterized in that, The recovery rate of tin is 85%-96%, and the loss rate of tin in the gravity separation tailings is less than or equal to 1.9%.

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