Flotation collecting agent and preparation method and application thereof

Abstract

The invention discloses a flotation collecting agent and a preparation method and application thereof, and relates to the technical field of mineral separation. The flotation collecting agent comprises carbonized methyl carbamate, zinc diethyldithiocarbamate, butyl octanol and sulfate according to the mass ratio of (3-6): (1-12): (2-3): (3-8). According to the prepared composite flotation reagent, in the cassiterite ore flotation treatment process, after one-time roughing, three-time scavenging and three-time concentration, the loss of easily-argillized fine-grain and micro-fine-grain cassiterite in tailings is reduced, the cassiterite content in cassiterite ore is reduced through precise adsorption of the reagent, efficient recovery of the fine-grain and micro-fine-grain cassiterite is achieved, and the cassiterite flotation efficiency is improved. The effective recovery of cassiterite is improved, and the tin grade and the recovery rate in the tin concentrate are also remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ore dressing, and in particular, to a flotation collector, a preparation method thereof, and an application thereof. Background Art

[0002] Metallic tin (Sn) has a wide range of applications in fields such as electronic solders, semiconductors, batteries, solder alloys, etc., and is particularly indispensable in the electronics industry and the solder industry. Cassiterite (mainly composed of SnO2) is the main mineral raw material for extracting metallic tin. With the progress of technology, the demand for tin continues to grow, and as its main source, the importance of cassiterite is self-evident. However, the properties of cassiterite determine that it faces many challenges in the ore dressing process, and the common problems are as follows: (1) Cassiterite often coexists with other sulfide ores such as copper, lead, zinc, silver, etc. Due to the large differences in the properties of these minerals, during the grinding and separation process, it is easy to cause an increase in the content of fine and ultrafine cassiterite, reducing the recovery rate of cassiterite. (2) Cassiterite also often coexists with gangue minerals such as calcite, quartz, fluorite, etc. This symbiotic relationship reduces the grade and accuracy of cassiterite. (3) Fine and ultrafine cassiterite and gangue minerals are prone to slime formation during the grinding process, forming a slime cover on the mineral surface, further affecting the precise targeted adsorption of flotation reagents on the mineral surface, and thus affecting the ore dressing efficiency and recovery rate of cassiterite.

[0003] In view of this, the present invention is specifically proposed. Summary of the Invention

[0004] The purpose of the present invention is to provide a flotation collector, a preparation method thereof, and an application thereof to solve the above technical problems.

[0005] The present invention is implemented as follows: In the first aspect, an embodiment of the present invention provides a flotation collector, which includes methyl carbamate, zinc diethyldithiocarbamate, butyl octanol, and sulfate in a mass ratio of (3 - 6):(1 - 12):(2 - 3):(3 - 8).

[0006] In the second aspect, an embodiment of the present invention provides a preparation method of a flotation collector as described above, and the preparation method includes: Mix methyl carbamate, zinc diethyldithiocarbamate, butyl octanol, and sulfate in proportion, and then react for 120 min - 200 min under normal pressure and at a temperature of 50°C - 100°C to obtain the flotation collector.

[0007] In the third aspect, an embodiment of the present invention provides a composite flotation reagent, which includes the flotation collector as described above or the flotation collector prepared by the preparation method as described above, and at least one of an activator, a foaming agent, and an antifoaming agent; Among them, the activator is selected from any one of the following components: Component 1: Lead nitrate, alkyl sulfonic acid, and oxalic acid with a mass ratio of (0.5 - 1.5):(0.5 - 1.5):(0.5 - 1.5); Component 2: Lead nitrate and alkyl sulfonic acid with a mass ratio of 4:(2 - 5); The foaming agent is selected from at least one of camphor oil, pine needle oil, and cresylic acid; The defoaming agent is selected from at least one of palmitic acid, cottonseed oil, and castor oil.

[0008] Fourthly, an embodiment of the present invention provides an application of the flotation collector as described above, or the flotation collector prepared by the preparation method as described above, or the composite flotation reagent as described above in the flotation of cassiterite ore.

[0009] The present invention has the following beneficial effects: The flotation collector provided by the embodiment of the present invention belongs to a new type of organic collector, which is prepared by mixing methyl carbamate, zinc diethyldithiocarbamate, butyloctanol, and sulfate; the amino group (-NH2) and methyl formate (-COO) in the flotation collector selectively adsorb on the exposed crystal surface of cassiterite respectively and form stable chemical bonds, thereby improving the floatability of cassiterite.

[0010] The flotation collector is combined with at least one of the activator, foaming agent, and defoaming agent. The prepared composite flotation reagent reduces the loss of easily slime-forming fine and superfine cassiterite in the tailings during the flotation treatment of cassiterite ore. After one rough selection, three scavenging selections, and three cleaning selections, it can achieve the efficient recovery of fine and superfine cassiterite, improve the effective recovery of cassiterite, and significantly improve the tin grade and recovery rate in the tin concentrate. Description of the Drawings

[0011] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, so they should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other relevant drawings can also be obtained based on these drawings.

[0012] Figure 1 It is a process flow diagram of the flotation treatment of cassiterite ore in the embodiment of the present invention; Figure 2 It is an infrared test spectrum of the flotation collector. Detailed Embodiments

[0013] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below. Those not specified in the embodiments are carried out according to conventional conditions or conditions recommended by the manufacturer. Reagents or instruments not specified by the manufacturer are all conventional products that can be obtained through commercial purchase.

[0014] In a first aspect, an embodiment of the present invention provides a flotation collector, which includes methyl carbamate, zinc diethyldithiocarbamate, butyloctanol, and sulfate in a mass ratio of (3 - 6):(1 - 12):(2 - 3):(3 - 8).

[0015] It should be noted that during the ore flotation process, the collector adsorbs on the mineral surface to form a hydrophobic film, enhancing the hydrophobicity of the target mineral so that it can adhere to the bubbles and float out with the foam layer. The traditional collectors have the following deficiencies: (1) Traditional collectors (such as xanthates, dithiophosphates, or fatty acids) have an adsorption effect on various minerals, making it difficult to effectively separate the target mineral from gangue minerals, resulting in a decrease in the concentrate grade and an increase in subsequent smelting costs; (2) Traditional collectors (such as thiophosphates or cyanides) are toxic and may pollute water bodies or soil, not meeting the requirements of green mines; for example, alkyl sulfonates have poor biodegradability and may damage the ecological environment after long-term accumulation; (3) Traditional collectors have a weak collecting ability for extremely fine particles or oxidized ores, easily causing metal loss; (4) Slimes in complex ores (such as kaolin or montmorillonite) will adsorb the collector, resulting in poor adaptability of the collector, increased drug consumption, and deteriorated flotation indexes; (5) Collectors (such as dodecylamine) easily cause the foam to be too viscous or brittle, affecting the stability of flotation operations.

[0016] The flotation collector provided by the embodiment of the present invention belongs to a new type of organic collector, which is prepared by mixing methyl carbamate, zinc diethyldithiocarbamate, butyloctanol, and sulfate.

[0017] Among them, methyl carbamate has the following characteristics: after being modified by carboxylic acid-phosphonic acid bipolar groups, the carboxyl group (-COOH) and phosphonic acid group (-PO3H2) in its molecule can selectively chelate Sn on the cassiterite surface 4+ (the binding energy is increased by 3.8 times), forming a hydrophobic metal complex. At the same time, the mesoporous structure (specific surface area > 800m 2 / g) enhances the physical adsorption ability for fine-grained cassiterite.

[0018] Zinc diethyldithiocarbamate has the following characteristics: realizing controlled release through a temperature-sensitive microcapsule technology (PNIPAM coating), and its thiocarbamate group (-N-CSS -)(It) is rapidly exposed in the 35°C pulp, bonds with the oxygen vacancies on the surface of SnO2 to form a stable chemical adsorption layer, and significantly reduces the thickness of the hydration film on the mineral surface.

[0019] As an amphiphilic co-adsorbent, the long carbon chain (C8) of butyloctanol inserts into the methyl carbamate adsorption layer to strengthen the hydrophobicity of the mineral through hydrophobic association.

[0020] Sulfates (such as Na2SO4) pass through SO4 2- The ion exchange with the surface hydroxyl groups (-OH) of cassiterite exposes more Sn active sites, and at the same time adjusts the pulp potential to optimize the adsorption kinetics of the collector.

[0021] The use of the new organic collectors and their synergistic mechanism are as follows: Methyl carbamate provides specific chelating anchor points, zinc diethyldithiocarbamate dynamically supplements adsorption sites, butyloctanol enhances the extensibility of the hydrophobic chain, and sulfates activate the mineral surface. Through the triple effects of chemical bonding-hydrophobic assembly-potential regulation, the contact angle of cassiterite increases from 35° to 78°, the flotation rate constant increases by 2.3 times, and especially the recovery rate of -20μm fine-grained cassiterite is increased to more than 85%.

[0022] It should be noted that when the component dosage of the flotation collector is within the above-set ratio range, there is a good cassiterite collection effect, but it does not mean that there is only the above-mentioned ratio selection for the component dosage of the flotation collector; the mass ratio of methyl carbamate, zinc diethyldithiocarbamate, butyloctanol and sulfates can be selected from any one of 3:5:2:4, 4:8:2:6, 5:10:3:7, 5:12:3:5 and 6:12:3:8, or other values within the range of (3-6):(1-12):(2-3):(3-8). The amino groups (-NH2) and methyl formate groups (-COO) in the flotation collector selectively adsorb on the exposed cassiterite crystal planes (such as (110), (101), (200) and (211)), and among them, the O-C=O group, as an electron donor, establishes a spatial interaction of Sn-…O=C with the surface cations (Sn) on cassiterite, induces significant chemical bonding, and forms a stable chemical bond with the electron pair provided by the -NH2 group, improving the floatability of cassiterite.

[0023] It should be noted that when the component dosage of the flotation collector is within the above-set ratio range, there is a good cassiterite collection effect, but it does not mean that there is only the above-mentioned ratio selection for the component dosage of the flotation collector; the mass ratio of methyl carbamate, zinc diethyldithiocarbamate, butyloctanol and sulfates can be selected from any one of 3:5:2:4, 4:8:2:6, 5:10:3:7, 5:12:3:5 and 6:12:3:8, or other values within the range of (3-6):(1-12):(2-3):(3-8).

[0024] In other embodiments of the present invention, one or a combination of two components can be independently selected for ore flotation according to actual needs, such as achieving the effect of copper collection in the flotation process of chalcopyrite and pyrite.

[0025] In an alternative embodiment of the present invention, the sulfate is selected from at least one of sodium sulfate, zinc sulfate, ferrous sulfate, sulfated soap, alkyl sulfate, and petroleum sulfonate.

[0026] It should be noted that the sulfate reagent used in the present invention has a low cost and a wide source, but the dosage needs to be controlled according to the ore characteristics to avoid excessive inhibition or interference with the flotation system. Its functions are mainly reflected in the following aspects: Among them, sodium sulfate: focuses on physical regulation (dispersion, pH, ionic strength), and is suitable for oxidized ores with a lot of slime; it can inhibit the aggregation of fine slime, reduce the interference of slime on the flotation process (such as clay coating of valuable minerals), and avoid the influence of clay minerals (such as kaolinite) on the concentrate grade; in addition, it is also beneficial to increase the ionic strength of the pulp, improve the bubble stability, and enhance the flotation efficiency. Excessive dosage may interfere with the foam stability.

[0027] Zinc sulfate: specifically used to inhibit zinc minerals, and is a key reagent for lead-zinc / copper-zinc separation; when separating copper and zinc, zinc sulfate can inhibit zinc minerals and improve the purity of copper concentrate. It needs to be used in combination with cyanide or sulfite.

[0028] Ferrous sulfate: mainly inhibits pyrite, and has both reduction and environmental protection functions, reducing the pollution of sulfur to the concentrate; when flotation of sulfide ores (such as galena, chalcopyrite), ferrous sulfate can reduce the oxide film (such as PbSO4) on the mineral surface and restore its floatability; in the flotation tailings, Fe 2+ can precipitate heavy metal ions (such as Cu 2+ 、Zn 2+ ), reducing environmental pollution. It is easy to form Fe(OH)3 precipitate in an alkaline environment.

[0029] Sulfated soap: derived from natural raw materials, with better biodegradability than synthetic reagents; it can maintain good collecting performance under hard water conditions.

[0030] Alkyl sulfate: can significantly reduce the surface tension of water and form a stable foam layer, suitable for flotation systems that require high foam stability.

[0031] Petroleum sulfonate: has good effects on both sulfide ores (such as chalcopyrite, galena) and some oxidized ores (such as hematite); it has both collecting and emulsifying properties, can inhibit the interference of slime on flotation, and improve the dispersion of the pulp.

[0032] In a second aspect, an embodiment of the present invention provides a preparation method of a flotation collector as described above, and the preparation method includes: Mix methyl carbamate, zinc diethyldithiocarbamate, butyl octanol, and sulfate in proportion, and then react for 120 min - 200 min under normal pressure and at a temperature of 50°C - 100°C to obtain the flotation collector.

[0033] It should be noted that an increase in temperature generally accelerates the reaction kinetics, but too high a temperature may lead to side reactions, and too low a temperature may result in incomplete reactions. The reaction temperature directly affects the configuration or degree of branching of the molecular hydrophobic chains in the flotation collector. The reaction time can be reasonably adjusted according to the actual amount of material to be processed. If the time is insufficient, the reaction will be incomplete, and too long a reaction time may cause hydrolysis or oxidation, which is not conducive to the control of side reactions.

[0034] During the preparation process, in order to avoid problems such as local overheating and product deposition, and to ensure that the flotation collector is more uniform and the reaction is more complete, appropriate stirring treatment can be carried out.

[0035] Thirdly, the embodiments of the present invention provide a composite flotation reagent, which includes the flotation collector as described above or the flotation collector prepared by the preparation method as described above, and at least one of an activator, a foaming agent, and an antifoaming agent; Among them, the activator is selected from any one of the following components: Component 1: Lead nitrate, alkyl sulfonic acid, and oxalic acid with a mass ratio of (0.5 - 1.5):(0.5 - 1.5):(0.5 - 1.5); Component 2: Lead nitrate and alkyl sulfonic acid with a mass ratio of 4:(2 - 5); The foaming agent is selected from at least one of camphor oil, pine needle oil, and cresylic acid; The antifoaming agent is selected from at least one of palmitic acid, cottonseed oil, and castor oil.

[0036] It should be noted that the collector determines the floatability of minerals, the activator broadens the floatability range of minerals, the foaming agent ensures bubble transport, and the antifoaming agent optimizes the foam structure. Through reasonable combination, they can reduce the types and dosages of reagents, and achieve a flotation effect with high selectivity, high recovery rate, and low reagent consumption, which is particularly important for complex symbiotic ores. The specific functions of each substance in the flotation process are as follows: Among them, the activator forms an active film on the mineral surface (such as Cu 2+ displaces Zn 2+ to form a CuS film), which is used to change the surface properties of the mineral, enhance the adsorption of the collector or relieve the inhibited state; in addition, it also has the effect of removing the oxide layer. Among them, lead nitrate has the characteristic of selective activation, which can reduce the activation of gangue; through the adsorption of Pb 2+ on the mineral surface to form active sites, significantly enhancing the adsorption ability of the collector.

[0037] Alkyl sulfonic acid has both activation and collection functions. Specifically, the sulfonic acid group (-SO3H) can react with metal ions on the mineral surface (such as Ca 2+ , Fe 3+)(Combined with the collector, it exposes the hydrophobic alkyl chain (R-), enhancing the floatability of minerals; it can also be directly used as an anionic collector. It can still be effectively adsorbed in the pulp with high calcium and magnesium ion concentrations, overcoming the problem of easy precipitation of traditional fatty acid collectors. Compared with traditional activators (such as dichromate), alkyl sulfonic acid has low toxicity and better meets the requirements of green mineral processing.)

[0038] )(The strong complexing ability of oxalic acid can dissolve the oxide and hydroxide films on the mineral surface (such as PbSO4, Fe(OH)3), restoring the natural floatability of minerals; it also has a pH adjustment function and can complex Ca 2+ , Fe 3+ etc. in the pulp, reducing their interference with flotation. In addition, oxalic acid is inexpensive, and its degradation products are CO2 and H2O, which is environmentally friendly.)

[0039] )(When the activator selects Component 1, the mass ratio of lead nitrate, alkyl sulfonic acid and oxalic acid can be selected from any one of 0.5:1.0:1.2, 1.0:1.5:1.2, 1.0:1.0:1.0, 1.2:1.3:1.2 and 1.5:1.0:1.3 according to actual needs, or other values within the range of (0.5-1.5):(0.5-1.5):(0.5-1.5); )(When the activator selects Component 2, the mass ratio of lead nitrate and alkyl sulfonic acid can be selected from any one of 4:2, 4:3, 4:4 and 4:5 according to actual needs, or other values within the range of 4:(2-5).)

[0040] )(The frother is used to reduce the gas-liquid interfacial tension, form a stable bubble layer, and carry the hydrophobic minerals to float. The action mechanism of the frother is that its polar group is hydrophilic and the non-polar group is gas-philic, forming a bubble structure, and then forming a stable bubble layer, and carrying the hydrophobic minerals to float.)

[0041] )(In the optional embodiments of the present invention, camphor oil, pine needle oil and cresylic acid used as natural or semi-synthetic frothers show irreplaceable advantages in specific flotation scenarios due to their unique chemical structures and physical properties. Specifically as follows: )(Among them, camphor oil is a by-product of camphor refining, containing natural components such as camphene, cineole, and terpenol. It has both foaming properties and moderate collecting properties, and is especially suitable for the flotation of fine-grained minerals; it can still maintain the characteristics of stable foam in low-temperature pulp.)

[0042] Pine needle oil contains terpene compounds such as α-pinene and β-pinene, and the formed foam layer has a dense structure, which can effectively carry coarse-grained minerals (such as apatite and feldspar); the polar components (such as terpineol) it contains can be adsorbed on the surface of slime, reducing its damage to the foam; its combination with alkyl sulfonate is beneficial to prolong the foam life and adapt to high-salinity pulp. Pine needle oil has irreplaceable characteristics in salt minerals due to its strong anti-interference ability and coarse-grained carrying characteristics. If camphor oil and pine needle oil are compounded and used, the foaming agent is conducive to the stability of the foam while taking into account the low-temperature activity.

[0043] The benzene ring structure and hydroxyl group in cresylic acid enable it to not only reduce the surface tension but also weakly bind to metal ions (such as Cu 2+ 、Pb 2+ ) on the mineral surface, especially suitable for the mixed system of sulfide ore and oxidized ore; its dual-functional characteristics make it firmly established in the flotation of complex sulfide ores, but the toxicity problem needs to be balanced. It is easy to regulate the fluidity of the foam, provide strong foaming ability, and the generated foam has moderate brittleness, which is convenient for quickly scraping the foam in the cleaning section and reducing the retained impurities.

[0044] The defoaming agent is used when the foam is too viscous in the cleaning section or scavenging section. It is beneficial to destroy the overly stable foam, control the thickness of the foam layer, and prevent the concentrate from entraining impurities.

[0045] It should be noted that different combinations of components in the composite flotation reagent have different effects. Specifically in the implementation mode, reasonable combinations can be made according to actual needs to achieve the final effect: for example, the combined use of a collector and an activator can significantly improve the recovery rate of difficult-to-float minerals; the combined use of a collector and a foaming agent can balance the floating speed of minerals and the stability of the foam; the combined use of a foaming agent and a defoaming agent can accurately control the foam layer and improve the concentrate grade. The main application is to add a small amount of defoaming agent in the cleaning section to reduce the entrainment of fine-grained gangue. If the activator is combined with an inhibitor, it can selectively separate associated minerals.

[0046] In addition, the following aspects need to be noted during the combined use of the composite flotation reagent: the activator needs to be added before the collector, and the inhibitor is usually added before the collector; the use of excessive activator may cause non-target minerals to float (such as too much Cu 2+ will activate gangue), and too much foaming agent will reduce the selectivity of the composite flotation reagent.

[0047] Fourthly, the embodiments of the present invention provide an application of the flotation collector as described above or the flotation collector prepared by the preparation method as described above or the composite flotation reagent as described above in the flotation of cassiterite ore.

[0048] In an alternative embodiment of the present invention, the flotation of cassiterite ore includes the following steps: After grinding and classifying the tin polymetallic ore, a mixed ore pulp is prepared for standby. After subjecting the mixed ore pulp to flotation treatment, tin concentrate is obtained. Among them, the flotation treatment includes one rough selection, three scavenging selections, and three cleaning selections carried out in sequence; the rough selection obtains the pulp after rough selection, and each scavenging selection respectively obtains the pulp after scavenging selection, and each cleaning selection respectively obtains the pulp after cleaning selection.

[0049] It should be noted that the cassiterite ore in the embodiment of the present invention is a tin polymetallic ore, which belongs to the low-grade complex type of ore (the average grade of cassiterite is below 0.21%-0.35%). The main metal mineral composition in this ore is cassiterite, galena, and marmatite, and the gangue minerals are mainly quartz, muscovite, fluorite, etc. The tin content in the ore is 0.61%-0.70%, the average grade of the main valuable element copper is 0.66%-2.36%, and the average grade of sulfur is 5.52%-25.00%. In view of the many challenges faced by cassiterite ore in the beneficiation process, in an alternative embodiment of the present invention, its flotation process is optimized, and the specific process is as follows: After grinding and classifying the low-grade complex tin polymetallic ore mixed ore material, a mixed ore pulp is prepared for standby.

[0050] It should be noted that the grinding treatment has the following characteristics: (1): By mechanical force, the ore structure is destroyed, so that the useful minerals (such as copper, iron, gold, etc.) are fully dissociated from the gangue (useless minerals), creating necessary conditions for subsequent separation (such as flotation, magnetic separation), and improving the beneficiation efficiency and recovery rate. (2) After grinding, the particle size of the mineral particles decreases, and the specific surface area increases significantly, accelerating the contact between the chemical reagent and the target mineral, and improving the reaction rate and recovery rate. (3) Optimizing the mineral particle size can avoid over-grinding or insufficient grinding, and can avoid the influence of too coarse or too fine mineral particles on the effect of subsequent separation processes. (4) Through sufficient dissociation, the loss of useful minerals (such as residues in tailings) can be reduced. (5) The fine particles after grinding are easy to transport or stir and mix, which is beneficial to reducing the transportation and smelting costs.

[0051] The grinding treatment can be carried out in dry grinding, wet grinding and other ways according to actual needs, and grinding media or additives can also be added for auxiliary grinding. In an alternative embodiment of the present invention, wet grinding is adopted. By mixing the ore with water and adding it to the grinding machine, the grinding treatment is carried out in a stirring and grinding manner to prepare a prefabricated mixed ore pulp.

[0052] After subjecting the prefabricated mixed ore pulp to classification treatment, a mixed ore pulp is obtained, and the proportion of the ore material with a particle size less than 0.074 mm in the mixed ore pulp is 75%-82%.

[0053] It should be noted that classifying the pulp minerals after grinding can avoid uneven particle sizes generated during the grinding process. For example, oversize particles (under-grinding) can cause the useful minerals to not be fully dissociated, while oversize particles (over-grinding) increase energy consumption and the risk of slime formation, in order to improve grinding efficiency, reduce energy consumption and steel ball consumption. In addition, the slime present in the minerals after grinding treatment has the risk of wrapping the useful mineral particles, hindering reagent adsorption (such as flotation), increasing the solution viscosity, and affecting sedimentation or magnetic separation efficiency. After classification treatment, separately treating or desliming the slime is beneficial to improving the concentrate grade and recovery rate.

[0054] Before the flotation treatment, it is also necessary to dilute the mixed pulp with water, where the concentration of the ore material with a particle size less than 0.074 mm is 20% - 25%. After the mixed pulp is subjected to flotation treatment, tin concentrate is obtained; among them, the flotation treatment includes one rough selection, three scavenging selections, and three cleaning selections carried out in sequence; the rough selection obtains the pulp after rough selection, and each scavenging selection respectively obtains the pulp after scavenging selection, and each cleaning selection respectively obtains the pulp after cleaning selection.

[0055] It should be noted that each process section of the flotation treatment has different functions and characteristics, and it is mainly used to balance the recovery rate of the concentrate and the quality of the concentrate. The actual flotation process will be adjusted according to the ore properties (such as particle size, mineral symbiotic relationship), and may include multiple scavenging selections or multiple cleaning selections. In the implementation mode of the present invention, a flotation process with three scavenging selections and three cleaning selections is used.

[0056] Among them, the rough selection is used for the preliminary separation of the raw ore, quickly separating out most of the useful minerals and part of the gangue, obtaining the pulp after rough selection and part of the tin concentrate. It has the characteristics of a large processing volume, but a relatively low concentrate grade and may contain more impurities.

[0057] The scavenging selection is used for reprocessing the pulp after rough selection or the pulp after scavenging selection to recover the remaining useful minerals therein and reduce metal losses. It focuses on improving the recovery rate, and the pulp after scavenging selection is usually returned to the rough selection or separately treated.

[0058] The cleaning selection is used for further purification of the pulp after scavenging selection or the pulp after cleaning selection, removing the entrained gangue through multiple flotation operations to improve the final concentrate grade. The implementation of multi-stage cleaning selection ensures that the concentrate meets the smelting or sales standards.

[0059] It should be noted that the above-mentioned rough selection, scavenging selection, and cleaning selection all refer to one flotation operation, that is, a total of seven flotation steps are carried out in the flotation process of the present invention; and the pulp after rough selection obtained in the rough selection process, that is, the rough selection tailing pulp, is used as the pulp raw material for the first scavenging selection, and the pulp after scavenging selection obtained in the first scavenging selection, that is, the scavenging selection tailing pulp, is used as the pulp raw material for the second scavenging selection, and so on.

[0060] In each flotation operation, there should be corresponding stirring and aeration methods. In the embodiments of the present invention, any conventional or unconventional stirring methods such as mechanical impeller stirring and rotor stirring, and erosion methods such as gas precipitation type or pressure dissolved air type can be adopted.

[0061] The present invention does not make specific limitations on the setting of flotation parameters or types, and they can be reasonably adjusted according to actual needs to achieve mineral separation.

[0062] In the optional embodiments of the present invention, the flotation treatment includes at least one of the following features: Feature 1: The rough selection includes adding a first composite flotation reagent to the mixed pulp for flotation treatment to obtain partial tin concentrate and the pulp after rough selection.

[0063] It should be noted that the tin concentrate is uniformly recovered and treated, and the pulp after rough selection is used as the raw material for scavenging for further flotation treatment.

[0064] Feature 2: Each scavenging includes adding a second composite flotation reagent to the pulp after rough selection or the pulp after scavenging for flotation treatment to obtain partial tin concentrate and the pulp after scavenging.

[0065] It should be noted that there are three scavengings. The tin concentrate obtained from each scavenging is uniformly recovered and treated. The pulp after the first scavenging is used as the raw material for the second scavenging for flotation; the pulp after the second scavenging is used as the raw material for the third scavenging for flotation; the pulp after the third scavenging is used as the raw material for cleaning for flotation.

[0066] Feature 3: Each cleaning includes flotation treatment of the pulp after scavenging or the pulp after cleaning, without adding reagents during this period, to obtain partial tin concentrate and the pulp after cleaning.

[0067] It should be noted that there are three cleanings. The tin concentrate obtained from each cleaning is uniformly recovered and treated. The pulp after the first cleaning is used as the raw material for the second cleaning for flotation; the pulp after the second cleaning is used as the raw material for the third cleaning for flotation; the pulp after the third cleaning is recovered and treated.

[0068] In the optional embodiments of the present invention, based on the mass of the pulp, the first composite flotation reagent added during the rough selection process includes: 50 g / t - 1000 g / t of flotation collector, 50 g / t - 80 g / t of activator, 10 g / t - 20 g / t of defoamer, and 10 g / t - 20 g / t of foaming agent.

[0069] In the optional embodiments of the present invention, based on the mass of the pulp, the second composite flotation reagent added during the scavenging process includes: 30 g / t - 1000 g / t of flotation collector; 30 g / t - 50 g / t of activator.

[0070] It should be noted that the composite flotation reagents added in rough selection and scavenging are different mainly to optimize the separation targets at different stages and improve the recovery rate of useful minerals and the concentrate grade. Among them, rough selection is to quickly float out most of the useful minerals to avoid the loss of useful minerals into the tailings. Scavenging is to recover the residual useful minerals in the roughing tailings and further reduce the tailings grade; if too much collector is added in scavenging, it may cause gangue to float and increase the burden of cleaning.

[0071] In an optional embodiment of the present invention, during the flotation treatment process, both the flotation collector and the activator are added in the form of a solution; Among them, the mass concentration of the flotation collector solution is 1%-3%; the mass concentration of the activator solution is 3%-5%.

[0072] It should be noted that adding the flotation collector and the activator in the form of an aqueous solution has the following characteristics compared with directly adding the reagents: (1) It is beneficial to make the flotation collector evenly adsorb on the surface of the target minerals and reduce reagent waste; the activator fully contacts the minerals to be activated and avoids the "dead zone" effect. (2) Reduce the loss of the reagent adhering to the inner wall of the equipment or pipeline, reduce the collection efficiency, and increase the operating cost.

[0073] The setting of the mass concentration can be reasonably adjusted according to actual needs. Among them, the mass concentration of the flotation collector solution can be selected from any one of 1%, 1.5%, 2%, 2.5% and 3%, or other values within the range of 1%-3%; the mass concentration of the activator solution can be selected from any one of 3%, 3.5%, 4%, 4.5% and 5%, or other values within the range of 3%-5%.

[0074] The features and performance of the present invention will be further described in detail below in conjunction with the embodiments.

[0075] Example 1 This example provides a flotation collector, and its preparation steps are specifically as follows: Methyl carbamate, zinc diethyldithiocarbamate, butyloctanol and sodium sulfate are mixed in proportion, and then reacted for 120 min under normal pressure and at a temperature of 50°C to obtain the flotation collector.

[0076] Among them, the mass ratio of methyl carbamate, zinc diethyldithiocarbamate, butyloctanol and sodium sulfate is 3:1:2:3.

[0077] This example also provides a composite flotation reagent, and its specific components include: the above-mentioned flotation collector, activator, foaming agent and defoaming agent, denoted as the first composite flotation reagent.

[0078] Among them, the activator is lead nitrate, alkyl sulfonic acid, and oxalic acid with a mass ratio of 1:1:1; the foaming agent is pine oil alcohol, and the defoaming agent is P86.

[0079] Example 2 This example provides a composite flotation reagent, and the difference in its specific components from those of Example 1 is only that: The specific components of the activator in the composite flotation reagent are different: lead nitrate and alkyl sulfonic acid with a mass ratio of 4:3, denoted as the second composite flotation reagent.

[0080] Example 3 This example provides a composite flotation reagent, and the difference in its specific components from those of Example 1 is only that: In the first composite flotation collector, the mass ratio of methyl carbamate, zinc diethyldithiocarbamate, butyloctanol, and sodium sulfate is 6:12:3:8.

[0081] Example 4 This example provides a composite flotation reagent, and the difference in its specific components from those of Example 1 is only that: In the first composite flotation collector, the mass ratio of methyl carbamate, zinc diethyldithiocarbamate, butyloctanol, and sodium sulfate is 3:5:2:8.

[0082] Application Example 1 This application example uses the composite flotation reagent of Example 1 for cassiterite ore flotation. The specific flotation process includes the following steps: (1) After grinding and classifying the raw ore, a mixed ore pulp is prepared for later use; Among them, the raw material is from the raw ore of a tin mine in Jiangxi, with a tin grade of 0.35% and a sulfur grade of 23.25%.

[0083] (2) After flotation treatment of the mixed ore pulp, tin concentrate is obtained; Among them, the flotation treatment includes one rough selection, three scavenging selections, and three cleaning selections; The rough selection is to add the first composite flotation reagent to the mixed ore pulp for rough selection treatment to obtain partial tin concentrate and the roughened ore pulp; among them, the first composite flotation reagent includes 100 g / t of flotation collector, 50 g / t of activator, 10 g / t of defoaming agent, and 10 g / t of foaming agent; among them, the mass concentration of the flotation collector is 1%, and the mass concentration of the activator is 3%; the activator includes lead nitrate, alkyl sulfonic acid, and oxalic acid with a mass ratio of 1:1:1.

[0084] The second composite flotation reagent is added to the rougher concentrate pulp for scavenging treatment to obtain part of the tin concentrate and the first scavenged pulp; the second composite flotation reagent is added to the first scavenged pulp for flotation treatment to obtain part of the tin concentrate and the second scavenged pulp; the second scavenged pulp is subjected to flotation treatment without adding reagents during the process to obtain part of the tin concentrate and the cleaned pulp. Among them, the second composite flotation reagent includes 30 g / t of flotation collector; 30 g / t of activator; among them, the mass concentration of the flotation collector is 2%, and the mass concentration of the activator is 4%; the activator includes lead nitrate and alkyl sulfonic acid with a mass ratio of 4:3.

[0085] The tin concentrate obtained by roughing is subjected to cleaning treatment without adding reagents during the process to obtain part of the tin concentrate and the first cleaned pulp; the second composite flotation reagent is added to the first cleaned pulp for flotation treatment to obtain part of the tin concentrate and the second cleaned pulp; the second cleaned pulp is subjected to flotation treatment without adding reagents during the process to obtain part of the tin concentrate and the cleaned concentrate pulp.

[0086] By chemical titration, the tin grade in the cleaned concentrate pulp is obtained as 4.21%, and the tin recovery rate is 55.68%.

[0087] Application Example 2 This application example provides a cassiterite flotation. The specific flotation process is the same as that of Application Example 1, and the only difference is that the second composite flotation reagent used is the second composite flotation reagent prepared in Example 2 for cassiterite flotation.

[0088] By chemical titration, the tin grade in the cleaned concentrate pulp is obtained as 5.98%, and the tin recovery rate is 85.02%.

[0089] Application Example 3 This application example provides a cassiterite flotation. The specific flotation process is the same as that of Application Example 1, and the only difference is that the first composite flotation reagent used is the first composite flotation reagent prepared in Example 3 for cassiterite flotation.

[0090] By chemical titration, the tin grade in the cleaned concentrate pulp is obtained as 5.45%, and the tin recovery rate is 84.21%.

[0091] Application Example 4 This application example provides a cassiterite flotation. The specific flotation process is the same as that of Application Example 1, and the only difference is that the first composite flotation reagent used is the first composite flotation reagent prepared in Example 4 for cassiterite flotation.

[0092] By chemical titration, the tin grade in the cleaned concentrate pulp is obtained as 5.68%, and the tin recovery rate is 84.84%.

[0093] Comparative Example 1 This comparative example provides a cassiterite flotation. The specific flotation process is the same as that of Application Example 1, except that in this comparative example, a traditional reagent (benzohydroxamic acid) is used for cassiterite flotation. Among them, the raw material is from a tin-containing mine in Guangxi, with a tin grade of 0.58% and a sulfur grade of 12.25% in the original ore. After chemical titration, the tin grade in the concentrated ore pulp is 5.01%, and the tin recovery rate is 70.24%.

[0094] Comparative Example 2 This comparative example provides a cassiterite flotation. Compared with the specific flotation process of Application Example 1, the only difference is that: One roughing, two scavengings, and two cleanings processes are adopted.

[0095] After chemical titration, the tin grade in the concentrated ore pulp is 4.34%, and the tin recovery rate is 65.24%.

[0096] Test Example 1 This test example conducts an infrared absorption test on the flotation collector prepared in Example 1. The schematic diagram of the relevant test results is shown in Figure 2 .

[0097] From Figure 2 it can be seen that the peak at 1500.14 cm -1 is attributed to the C-N stretching vibration. In the molecule, the peaks at 1427.62 cm -1 , 1353.94 cm -1 and 1144.22 cm -1 are usually related to the C-H and C-O stretching vibrations. It shows that the C=O group and N-H bond in the reagent molecule can undergo enhanced adsorption on the Sn(IV) surface. This interaction indicates that Sn and the C=O bond undergo chemisorption through weak interactions, thereby strengthening the role of these functional groups in improving the floatability of cassiterite.

[0098] In summary, the flotation collector provided by the present invention solves the defects of poor recovery effect and high cassiterite content in tailings caused by poor precise adsorption of conventional flotation reagents during the flotation of fine and superfine cassiterite; effectively solves the problem of efficient recovery of low-grade tin polymetallic complex symbiotic fine and superfine cassiterite. In cassiterite flotation, by using specific flotation reagents and flotation process methods, through grinding, classification, one roughing, three scavengings, and three cleanings, a tin concentrate product can be effectively recovered.

[0099] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A flotation collector, characterized in that, The flotation collector comprises methyl carbamate, zinc diethyldithiocarbamate, butyloctanol and sulfate in a mass ratio of (3 - 6):(1 - 12):(2 - 3):(3 - 8).

2. The flotation collector according to claim 1, characterized in that, The sulfate is selected from at least one of sodium sulfate, zinc sulfate, ferrous sulfate, sulfated soap, alkyl sulfate and petroleum sulfonate.

3. A preparation method of the flotation collector as described in claim 1 or 2, characterized in that, The preparation method comprises the following steps: After mixing methyl carbamate, zinc diethyldithiocarbamate, butyloctanol and sulfate in proportion, reacting for 120 min - 200 min under normal pressure and at a temperature of 50°C - 100°C, the flotation collector is obtained.

4. A composite flotation reagent, characterized in that, The composite flotation reagent comprises the flotation collector as described in any one of claims 1 - 2 or the flotation collector prepared by the preparation method as described in claim 3, and at least one of an activator, a foaming agent and an antifoaming agent; Among them, the activator is selected from any one of the following components: Component one: lead nitrate, alkyl sulfonic acid and oxalic acid in a mass ratio of (0.5 - 1.5):(0.5 - 1.5):(0.5 - 1.5); Component two: lead nitrate and alkyl sulfonic acid in a mass ratio of 4:(2 - 5); The foaming agent is selected from at least one of camphor oil, pine needle oil and cresylic acid; The antifoaming agent is selected from at least one of palmitic acid, cottonseed oil and castor oil.

5. Application of the flotation collector as described in any one of claims 1 - 2 or the flotation collector prepared by the preparation method as described in claim 3 or the composite flotation reagent as described in claim 4 in the flotation of cassiterite ore.

6. The application according to claim 5, characterized in that, The flotation of cassiterite ore comprises the following steps: After grinding and classifying the tin polymetallic ore, a mixed pulp is obtained and reserved; After subjecting the mixed pulp to flotation treatment, tin concentrate is obtained; Among them, the flotation treatment comprises one roughing, three scavengings and three cleanings carried out in sequence; after roughing, the pulp after roughing is obtained, and after each scavenging, the pulp after scavenging is obtained respectively, and after each cleaning, the pulp after cleaning is obtained respectively.

7. The application according to claim 6, wherein The flotation treatment comprises at least one of the following features: Feature one: The roughing comprises adding a first composite flotation reagent to the mixed pulp for flotation treatment to obtain partial tin concentrate and the pulp after roughing; Feature two: Each scavenging comprises adding a second composite flotation reagent to the pulp after roughing or the pulp after scavenging for flotation treatment to obtain partial tin concentrate and the pulp after scavenging; Feature three: Each cleaning comprises subjecting the pulp after scavenging or the pulp after cleaning to flotation treatment without adding reagents during this period to obtain partial tin concentrate and the pulp after cleaning.

8. The application according to claim 7, characterized in that, Based on the mass of the pulp, the first composite flotation reagent added during roughing comprises: 50 g / t - 1000 g / t of flotation collector, 50 g / t - 80 g / t of activator, 10 g / t - 20 g / t of antifoaming agent and 10 g / t - 20 g / t of foaming agent.

9. The application according to claim 7, wherein Based on the mass of the pulp, the second composite flotation reagent added during scavenging comprises: 30 g / t - 1000 g / t of flotation collector; 30 g / t - 50 g / t of activator.

10. The application according to claim 8 or 9, characterized in that, During the flotation treatment process, both the flotation collector and the activator are added in the form of a solution; Among them, the mass concentration of the flotation collector solution is 1% - 3%; The mass concentration of the activator solution is 3% - 5%.

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