Combined beneficiation method for low-grade, high-mud-content and fine-grained tin tailings

Abstract

A combined beneficiation method for low-grade, high-mud-content and fine-grained tin tailings, comprising the following steps: (1) gravity pre-enrichment: preparing a pulp from raw ore having a particle size of -0.074 mm, and then using a suspended vibration concentrator to perform primary roughing pre-enrichment on the obtained ore pulp to obtain a pre-enriched product; (2) desulfurization flotation: concentrating and dehydrating the pre-enriched product, and if the pre-enriched product contains sulfur, performing desulfurization flotation, wherein the desulfurization flotation comprises roughing, scavenging and concentration, and if the pre-enriched product does not contain sulfur, directly entering step (3); (3) cassiterite flotation: performing cassiterite flotation on the sulfur-free pre-enriched product or desulfurized product in step (2), wherein the cassiterite flotation comprises roughing, scavenging and concentration; and (4) gravity concentration: using a gravity concentrator to separate the finally concentrated product in the cassiterite flotation in step (3) to obtain high-grade tin concentrate and low-grade tin concentrate. The beneficiation method has the advantages of reducing the costs, and improving the beneficiation recovery rate and the product quality.

Description

A combined beneficiation method for low-grade, high-mud content, fine-grained tin tailings Technical Field

[0001] The invention belongs to the field of fine-grained tin resource recovery, and in particular relates to a combined beneficiation method for low-grade, high-mud content, fine-grained tin tailings. Background Art

[0002] Cassiterite is brittle and easily sludged. It is prone to over-crushing during the crushing and grinding processes, producing large amounts of fine-grained cassiterite. This fine-grained cassiterite is difficult to effectively recover using traditional shaking table beneficiation, and is subsequently discharged into the tailings. According to statistics, one-third of the world's tin ore resources are lost as fine particles in tailings, and 80% of my country's tin metal is lost as fine mud. Tailings are typically fine-grained, and grinding of the raw ore produces secondary mud. This, combined with some primary mud, also ends up in the tailings. Therefore, a high mud content is a hallmark of tin tailings resources. Low grade, fine particle size, and high mud content are the primary factors contributing to low tin tailings recovery rates and high processing costs. The efficient and economical development of tin tailings has become a major challenge for mineral processing technology both domestically and internationally.

[0003] The main beneficiation processes for tin tailings are shaker gravity separation and flotation. The lower limit of the particle size recovery of traditional shakers is +0.038mm. For fine mud tailings of -0.038mm, the recovery efficiency of shaker gravity separation is very limited, and the processing capacity is small, making it difficult to achieve industrial application. If a single flotation process is used, the fine mud will have a significant impact on it, resulting in high reagent consumption, high costs, and low concentrate product quality, and economic benefits cannot be guaranteed. We have found the following patents for the process of recovering fine-grained cassiterite:

[0004] 1. Patent application number: 201510011445.4, invention title: A method for pre-slurrying and classification of gravity ore and its application, wherein the fine-grained ore mud enters flotation as overflow, and the flotation stage includes the following steps: (3.1) magnetic separation is first performed on the overflow to obtain magnetic products and non-magnetic products, and the obtained magnetic products are recovered for standby use; (3.2) the non-magnetic products after magnetic separation are concentrated; (3.3) the concentrated products are subjected to sulfur flotation; the sulfur flotation includes at least two concentrations and at least three scavengings; wherein the overflow water after concentration is recycled for use The method comprises the following steps: (1) selecting the product from step (3.3) and performing rough cassiterite flotation on the product after scavenging; (2) selecting the product from step (3.3) and performing rough cassiterite flotation on the product after rough cassiterite flotation; (3.5) selecting and scavenging the product from rough cassiterite flotation; (3.5) selecting the product from rough cassiterite flotation on the product after at least four selections and at least three scavengings; (3.6) feeding the selected product from step (3.5) into a recovery device to obtain tin concentrate; (3.7) obtaining tailings after at least three scavengings, wherein the recovery device uses a fast fine mud shaker, a suspended vibrating cone concentrator, or a centrifugal device. This patent uses a combined "flotation-gravity" process to process fine-grained ore. Flotation requires one roughing, at least four selections, and at least three scavengings, resulting in high reagent consumption and high costs. The same problem can also be seen in a method for cassiterite flotation of gravity-selected tailings disclosed in patent application number 201510011492.9.

[0005] 2. Patent Application No. 202310224711.6, Invention Title: A Polymetallic Tin Placer Ore Beneficiation Process Using an Isofloatable-Co-floatation-Gravity Separation Recycled Water Process: Tin concentrate yield 0.39%, tin content 40.57%, tin recovery rate 51.66%; low-grade tin concentrate yield 0.51%, tin content 3.17%, tin recovery rate 5.28%. The patent's main innovation lies in the isofloatable-co-floatation process. For fine-grade materials (-0.038mm), a single suspended vibrating disc concentrator for gravity separation and a single shaker table for gravity separation are used. As is known to those skilled in the art, the recovery limit of conventional shaker tables is +0.038mm. The recovery efficiency of shaker table gravity separation for fine tailings (-0.038mm) is very limited. Ultimately, the tin concentrate grade recovered from the fine-grade tailings in this patented process only reaches 1.73%.

[0006] Currently, there is a lack of economical and efficient mineral processing technology to recover low-grade, high-mud content fine-grained tin tailings.

[0007] Summary of the Invention

[0008] The purpose of the present invention is to solve the above technical problems and provide a combined beneficiation method for low-grade, high-mud content, fine-grained tin tailings that can reduce costs, improve mineral processing recovery rate and product quality, and effectively recover fine-grained tin tailings.

[0009] To achieve the above-mentioned purpose, the technical solution of the present invention is:

[0010] A combined beneficiation method for low-grade, high-mud content, fine-grained tin tailings comprises the following steps:

[0011] (1) Gravity pre-enrichment: The raw ore with a particle size of -0.074 mm is slurried, and the resulting slurry is then subjected to a roughing pre-enrichment using a suspended vibrating concentrator to obtain a pre-enriched product;

[0012] (2) Desulfurization flotation: The pre-enriched product is concentrated and dehydrated. If the pre-enriched product contains sulfur, desulfurization flotation is performed. The desulfurization flotation includes roughing, scavenging and concentrating. If the pre-enriched product does not contain sulfur, it directly enters step (3);

[0013] (3) cassiterite flotation: the sulfur-free pre-enriched product or the desulfurized product in step (2) is subjected to cassiterite flotation, wherein the cassiterite flotation includes roughing, scavenging and cleaning;

[0014] (4) Gravity separation: The final product from the cassiterite flotation in step (3) is separated by gravity separation equipment to obtain high-grade tin concentrate and low-grade tin concentrate.

[0015] As a further technical solution, in the above-mentioned raw ore, the tin grade is not greater than 0.5%, and the distribution rate of tin in the -0.037mm particle size is greater than the distribution rate in the +0.037mm-0.074mm particle size.

[0016] As a further technical solution, in the above-mentioned raw ore, the distribution rate of tin in the -0.037 mm particle size is not less than 50%.

[0017] As a further technical solution, the roughing conditions of the above-mentioned suspended vibration concentrator are: feed weight concentration of 10-25%, washing water volume of 10-23 ml / s, rotation frequency of 15-30 Hz, and vibration frequency of 25-30 Hz.

[0018] As a further technical solution, the above-mentioned desulfurization flotation includes a roughing selection, a scavenging selection and a cleaning selection, and any one or a combination of two or more of a collector, an activator and a frother is added to the desulfurization flotation.

[0019] As a further technical solution, in the above desulfurization flotation step, the first roughing step adds 25-50 g / t·ore of collector, 15-60 g / t·ore of activator and 10-20 g / t·ore of foaming agent; the first scavenging step adds 5-30 g / t·ore of collector; and the first concentrating step adds 0-5 g / t·ore of collector.

[0020] As a further technical solution, the above-mentioned cassiterite flotation includes one roughing selection, two scavenging selections and at least two cleaning selections, and any one or a combination of two or more of a collector, an activator and a frother is added to the cassiterite flotation.

[0021] As a further technical solution, in the above cassiterite flotation step, 450-600 g / t·ore of collector, 80-150 g / t·ore of activator and 10-30 g / t·ore of foaming agent are added in the first roughing; in the two scavenging, 100-300 g / t·ore of collector is added in each scavenging, and 5-20 g / t·ore of foaming agent is also added in the first scavenging; in the at least two concentrating, 0-100 g / t·ore of collector is added in each concentrating, and 5-10 g / t·ore of foaming agent is also added in the first concentrating.

[0022] As a further technical solution, the collector is any one of butyl xanthate, benzohydroxamic acid and BY9; the activator is copper sulfate or lead nitrate; and the foaming agent is 2# oil.

[0023] As a further technical solution, the gravity separation equipment in step (4) above includes a suspended vibration concentrator, a centrifugal concentrator or a high-frequency shaking table.

[0024] The 2# oil and BY9 mentioned in the present invention are conventional commercial products for mineral processing. The 2# oil is also known as pine oil; the main component of BY9 is salicylic hydroxamic acid.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The combined mineral processing method of the present invention can reduce costs and effectively recover fine-grained tin tailings. The present invention adopts a "gravity-floatation-gravity" combined beneficiation method to process fine-grained tin tailings with a tin grade of no more than 0.5% and a tin grade of -0.074 mm. Compared with the "floatation-gravity" process, the present invention not only reduces the amount of reagents used by more than 60%, but also recovers a high-tin concentrate grade of more than 41% and a recovery rate of more than 34%; a low-tin concentrate grade of more than 2.3% and a recovery rate of more than 25%; and a good comprehensive tin recovery rate of more than 60%. Furthermore, for fine-grained tin tailings with a distribution rate of not less than 75% and a particle size of -0.037 mm, which is more difficult to process, the process of the present invention reduces the amount of reagents used, while also recovering a high-tin concentrate grade of more than 38% and a recovery rate of more than 12%; a low-tin concentrate grade of more than 2.3% and a recovery rate of more than 17%; and a good comprehensive tin recovery rate of more than 30%. The obtained products all reach the sales grade, thereby realizing the resource recovery of low-grade and high-mud-content fine-grained tin tailings.

[0027] 2. In the "gravity-flotation-gravity" combined beneficiation method of the present invention, the first step of gravity separation adopts a suspended vibration concentrator as a gravity separation pre-enrichment means, which can directly select the entire amount of cassiterite without pre-desilting the original ore, reducing the loss of fine cassiterite, and can discard more than 60% of gangue and fine mud, thereby improving the grade of flotation feed, greatly reducing the impact of fine mud on subsequent operations, reducing the amount of reagents used, and reducing mineral processing costs; the cassiterite flotation of the present invention, through "one roughing selection, two scavenging selections and at least two cleaning selections" and the addition of a set combination of reagents, can recover the finer cassiterite therein, improve the grade of tin concentrate, increase the cassiterite recovery rate, and reduce the waste of tin resources; the tin ore obtained after cassiterite flotation is further sorted by gravity separation equipment (such as a high-frequency shaking table) to obtain sales-grade high-grade tin concentrate and low-grade tin concentrate, optimize the product structure, and increase economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG1 is a flow chart of a combined beneficiation method for low-grade, high-mud content, fine-grained tin tailings according to the present invention. DETAILED DESCRIPTION

[0029] The present invention will be further described in detail below with reference to examples, but the embodiments of the present invention are not limited to the scope of the examples.

[0030] Example 1

[0031] The ore processed in this embodiment is the fine-grained portion of a low-grade, high-mud content tin tailings after coarse separation. Its tin grade is 0.34%, the particle size is -0.074 mm, and it contains some pyrite. The multi-element analysis results (%) of the ore are shown in Table 1, and the particle size analysis results (%) are shown in Table 2.

[0032] Table 1 Multi-element analysis results of raw ore (%)

[0033] Table 2 Ore particle size analysis results (%)

[0034] The raw ore is the fine mud after the tailings discharged after traditional shaking table selection are separated. As can be seen in Table 2, the tin metal is mainly distributed in the -0.037mm particle size. When the shaking table is used for re-selection, the recovery efficiency is very limited, the effect is poor, and no economic benefits can be generated.

[0035] The main technical process of the present invention is the "heavy-float-heavy" process: the raw ore pulp is subjected to a roughing process using a suspended vibrating concentrator, the obtained coarse concentrate is subjected to a desulfurization flotation process of one roughing, one scavenging, and one concentrating process, and the desulfurization flotation tailings are subjected to a cassiterite flotation process of one roughing, two scavenging, and two concentrating process. After obtaining the tin middlings, a high-frequency shaking table is used for further concentrating to produce high-grade tin concentrate and low-grade tin concentrate. Main technical conditions:

[0036] (1) The raw ore pulp is not deslimed and is directly fed into the suspended vibrating concentrator for roughing. The roughing parameters are: feed mass concentration 20%, washing water volume 18 ml / s, rotation frequency 24 Hz, and vibration frequency 28 Hz.

[0037] (2) Desulfurization flotation reagent system: roughing time 3 min, butyl xanthate 33 g / t·original ore, copper sulfate 20 g / t·original ore, 2# oil 10 g / t·original ore; scavenging time 1.5 min, butyl xanthate 10 g / t·original ore; cleaning time 2 min, butyl xanthate 3 g / t·original ore.

[0038] (3) Cassiterite flotation reagent system: roughing time 5 min, benzohydroxamic acid 495 g / t·ore, lead nitrate 132 g / t·ore, 2# oil 13 g / t·ore; scavenging time 3 min, benzohydroxamic acid 165 g / t·ore, 2# oil 13 g / t·ore; scavenging time 2 min, benzohydroxamic acid 100 g / t·ore; concentrating time 1 6 min, benzohydroxamic acid 65 g / t·ore, 2# oil 10 g / t·ore; concentrating time 2 4.5 min, benzohydroxamic acid 50 g / t·ore.

[0039] (4) The high-frequency shaking table feeds ore at a mass concentration of 15% and a stroke of 8 mm.

[0040] Comparative Example 1:

[0041] Using the same raw ore as Example 1, Comparative Example 1 adopted a "floatation-gravity" process to recover the raw material. The main process flow is as follows: the raw material is first subjected to a desulfurization flotation process of one coarse, one scavenger, and one finer. The desulfurization flotation tailings are subjected to a cassiterite flotation process of one coarse, two scavengers, and two finers. After obtaining the tin middlings, a shaking table is used for further concentrating to produce a tin concentrate of saleable grade. Main technical conditions:

[0042] (1) The raw ore is not deslimed and is directly fed into flotation with a flotation concentration of 35%.

[0043] (2) Desulfurization flotation reagent system: roughing time 3.5 min, butyl xanthate 100 g / t·original ore, copper sulfate 60 g / t·original ore, 2# oil 30 g / t·original ore; scavenging time 1.5 min, butyl xanthate 20 g / t·original ore; cleaning time 1.5 min, 10 g / t·original ore.

[0044] (3) Cassiterite flotation reagent system: roughing time 5 min, benzohydroxamic acid 1800 g / t·ore, lead nitrate 400 g / t·ore, 2# oil 40 g / t·ore; scavenging time 3 min, benzohydroxamic acid 500 g / t·ore, 2# oil 10 g / t·ore; scavenging time 2.5 min, benzohydroxamic acid 300 g / t·ore; concentrating time 5 min, benzohydroxamic acid 200 g / t·ore, 2# oil 10 g / t·ore; concentrating time 4.5 min, benzohydroxamic acid 200 g / t·ore.

[0045] (4) High-frequency shaking table separation: feed weight concentration 15%, stroke 12mm.

[0046] Example 2:

[0047] The ore treated in this embodiment is a cassiterite flotation desliming overflow, with a tin grade of 0.097%, a particle size of -0.037 mm accounting for 85.56%, and contains some pyrite. The multi-element analysis results (%) of the ore are shown in Table 3, and the particle size analysis results (%) are shown in Table 4.

[0048] Table 3 Results of multi-element analysis of raw ore (%)

[0049] Table 4 Ore particle size analysis results (%)

[0050] This raw material is the overflow that needs to be deslimed and discharged when entering cassiterite flotation. It has extremely fine particle size and serious mudification. Using a single flotation method to recover the cassiterite will consume a lot of costs and cannot generate economic benefits.

[0051] The main technical process of the patented invention is the "heavy-float-heavy" process: the raw ore pulp is subjected to a roughing process using a suspended vibrating concentrator, the obtained coarse concentrate is subjected to a roughing process, a scavenging process, and a finishing process using desulfurization flotation, and the desulfurization flotation tailings are subjected to a cassiterite flotation process using a roughing process, a scavenging process, and a finishing process. After obtaining the tin middlings, a high-frequency shaking table is used for further concentrating to produce high-grade tin concentrate and low-grade tin concentrate. Main technical conditions:

[0052] (1) The raw ore pulp is not deslimed and is directly fed into the suspended vibrating concentrator for roughing. The roughing parameters are: feed concentration 15%, washing water volume 13 ml / s, rotation frequency 25 Hz, and vibration frequency 25 Hz.

[0053] (2) Desulfurization flotation reagent system: roughing time 4 min, xanthate 50 g / t·original ore, copper sulfate 50 g / t·original ore, 2# oil 15 g / t·original ore; scavenging time 2 min, xanthate 25 g / t·original ore; concentrating time 3.5 min, no reagent added.

[0054] (3) Cassiterite flotation reagent system: roughing time 6 min, BY9500 g / t·ore, lead nitrate 120 g / t·ore, 2# oil 15 g / t·ore; scavenging time 3 min, BY9180 g / t·ore, 2# oil 10 g / t·ore; scavenging time 2 min, BY9100 / t·ore; concentrating time 1 5 min, BY990 g / t·ore, 2# oil 5 g / t·ore; concentrating time 2 4 min, BY950 g / t·ore, concentrating time 3.5 min, BY925 g / t·ore.

[0055] (4) The high-frequency shaking table has an ore feed concentration of 15% and a stroke of 8 mm.

[0056] Example 3:

[0057] The raw ore processed in this embodiment is a tin tailing with a tin grade of 0.31%. In the tailing, iron and tin coexist densely and need to be ground to -0.037 mm.

[0058] Table 5 Multi-element analysis results of raw ore (%)

[0059] Table 6 Analysis results of raw ore ground to -0.037 mm particle size (%)

[0060] The raw ore is the tailings discharged after traditional shaking table selection. Due to the dense coexistence of iron and tin, it needs to be ground to -0.037mm to dissociate the cassiterite monomers.

[0061] The main technical process of the patented invention is the "re-float-re-re-weight" process: the raw ore pulp is subjected to a roughing process using a suspended vibrating concentrator, and the resulting coarse concentrate is subjected to cassiterite flotation in a process of one roughing, two sweeping, and two fine separations. After obtaining the tin middlings, a high-frequency shaking table is used for further concentrating to produce high-grade tin concentrate and low-grade tin concentrate. Main technical conditions:

[0062] (1) The raw ore is not deslimed and is directly fed into the suspended vibrating concentrator for roughing. The roughing parameters are: feed concentration 20%, washing water volume 20 ml / s, rotation frequency 22 Hz, and vibration frequency 30 Hz.

[0063] (2) Cassiterite flotation reagent system: roughing time 5 min, benzohydroxamic acid 600 g / t·ore, lead nitrate 120 g / t·ore, 2# oil 30 g / t·ore; scavenging time 3 min, benzohydroxamic acid 240 g / t·ore, 2# oil 10 g / t·ore; scavenging time 2 min, benzohydroxamic acid 120 g / t·ore; concentrating time 5 min, benzohydroxamic acid 80 g / t·ore, 2# oil 10 g / t·ore; concentrating time 4 min, benzohydroxamic acid 50 g / t·ore.

[0064] (3) The high-frequency shaking table has an ore feed concentration of 18% and a stroke of 10 mm.

[0065] Comparative Example 2

[0066] Under the same raw ore as Example 3, a traditional shaking table was used for separation. The main technical conditions were: the raw ore slurry was directly separated by a slurry shaking table, with a feed concentration of 20%, a stroke of 10 mm, a stroke rate of 465 r / min, and a bed slope of 4 degrees.

[0067] The comparison of tin recovery in Examples 1 to 3 and Comparative Examples 1 to 2 is shown in Table 7:

[0068] Table 7

[0069] It can be seen from Table 7 that:

[0070] (1) When Example 1 of the present invention treated tin tailings with a raw ore tin grade of 0.34% and a particle size of -0.074 mm, the tin concentrate grade was 41.53% and the recovery rate was 34.90%; the low tin concentrate grade was 2.38% and the recovery rate was 25.47%; the comprehensive tin recovery rate was 60.37%, which reduced the amount of reagents used by more than 60% compared with the direct raw ore flotation in Comparative Example 1. The comprehensive tin recovery rate of Comparative Example 1 was only 35.32%, which was much lower than the tin recovery rate of the present invention.

[0071] (2) Example 2 of the present invention is aimed at de-overflow, which cannot be effectively recovered by conventional processes. By adopting the present invention, a tin concentrate grade of 38.92% and a recovery rate of 12.43% can be obtained; a low tin concentrate grade of 3.02% and a recovery rate of 17.83%; and a comprehensive tin recovery rate of 30.26%, which are good indicators.

[0072] (3) When Example 3 of the present invention processes tin tailings with a tin grade of 0.31% and dense iron-tin paragenesis, a tin concentrate grade of 43.33% and a recovery rate of 40.78% are obtained; a low tin concentrate grade of 3.15% and a recovery rate of 26.34% are obtained, and the comprehensive tin recovery rate is 67.12%, which are good indicators; when Comparative Example 2 adopts the traditional shaking table separation process, a tin concentrate grade of 25.89% and a recovery rate of 39.26% can be obtained, which is a lower recovery rate.

[0073] It can be seen that the combined beneficiation process of "gravity-separation-gravity" of the present invention can achieve efficient and economical recovery of low-grade and high-mud content tin tailings compared with comparative examples 1 and 2, providing a new idea for the reuse of tin tailings.

[0074] In the mineral processing industry, roughing refers to the process of separating dirt, impurities, and gangue from the raw ore through primary separation, resulting in a concentrate product with a higher grade than the original ore. This process is called roughing. Scavenging refers to the process of removing tailings from the roughing process, which is not yet considered final waste and generally requires further processing. This process is called scavenging. Concentrating refers to the process of subjecting the roughing concentrate to secondary separation to obtain a qualified concentrate product. This process is called beneficiation and concentrating. Sometimes, the roughing concentrate requires multiple concentrating operations, sequentially referred to as primary concentrating, secondary concentrating, and tertiary concentrating, until the required concentrate grade is achieved. After concentrating, the ore is free of most gangue and impurities, resulting in an enriched concentration of useful minerals. Concentrate is the final product of the beneficiation plant and is generally used as a raw material for smelting. The final concentrate must meet national standards for both main components and impurity content to qualify as a qualified concentrate. The intermediate product obtained during the separation process is called middlings, and the useful content of middlings is generally between that of concentrates and tailings. The process steps not described in detail in this invention are understood in accordance with conventional operations.

[0075] The above embodiments are only specific examples to further illustrate the purpose, technical solutions and beneficial effects of the present invention, and the present invention is not limited thereto. Any modifications, equivalent replacements, improvements, etc. made within the scope of the present invention are included in the scope of protection of the present invention.

Claims

1. A combined beneficiation method for low-grade fine-grained tin tailings with high mud content, characterized in that, It includes the following steps: (1) Reselection for pre-concentration: The raw ore of -0.074mm particle size is slurried, and then the obtained pulp is subjected to one-stage roughing pre-concentration by a suspension vibration concentrator to obtain a pre-concentrated product. (2) Desulfurization flotation: The pre-concentrated product is concentrated and dewatered. If the pre-concentrated product contains sulfur, desulfurization flotation is carried out, and the desulfurization flotation includes roughing, scavenging and cleaning; if the pre-concentrated product does not contain sulfur, it directly enters step (3). (3) Cassiterite flotation: The sulfur-free pre-concentrated product or the product after desulfurization in step (2) is subjected to cassiterite flotation, and the cassiterite flotation includes roughing, scavenging and cleaning. (4) Gravity separation: The product finally selected in the cassiterite flotation in step (3) is separated by gravity separation equipment to obtain high-grade tin concentrate and low-grade tin concentrate.

2. A combined beneficiation method for low-grade and high-slime fine-grained tin tailings according to claim 1, characterized in that: In the raw ore, the grade of tin is not more than 0.5%, and the distribution rate of tin in the -0.037mm particle size grade is greater than that in the +0.037mm - 0.074mm particle size grade.

3. A combined beneficiation method for low-grade and high-slime fine-grained tin tailings according to claim 2, characterized in that: In the raw ore, the distribution rate of tin in the -0.037mm particle size grade is not less than 50%.

4. A combined beneficiation method for low-grade fine-grained tin tailings with high clay content according to claim 1, characterized in that, The roughing conditions of the suspension vibration concentrator are as follows: the feed weight concentration is 10 - 25%, the washing water volume is 10 - 23 ml / s, and the rotation frequency is 15 - 30 Hz.

5. A combined beneficiation method for low-grade and high-slime fine-grained tin tailings according to claim 1, characterized in that: The desulfurization flotation includes one-stage roughing, one-stage scavenging and one-stage cleaning, and any one or a combination of two or more of a collector, an activator and a frother is added in the desulfurization flotation.

6. The combined beneficiation method for low-grade fine-grained tin tailings with high mud content according to claim 5, characterized in that: In the desulfurization flotation step, 25 - 50 g / t·raw ore of collector, 15 - 60 g / t·raw ore of activator and 10 - 20 g / t·raw ore of frother are added in the one-stage roughing; 5 - 30 g / t·raw ore of collector is added in the one-stage scavenging; 0 - 5 g / t·raw ore of collector is added in the one-stage cleaning.

7. A combined beneficiation method for low-grade fine-grained tin tailings with high clay content according to claim 1, characterized in that: The cassiterite flotation includes one-stage roughing, two-stage scavenging and at least two-stage cleaning, and any one or a combination of two or more of a collector, an activator and a frother is added in the cassiterite flotation.

8. A combined beneficiation method for low-grade fine-grained tin tailings with high mud content according to claim 7, characterized in that: In the cassiterite flotation step, 450 - 600 g / t·raw ore of collector, 80 - 150 g / t·raw ore of activator and 10 - 30 g / t·raw ore of frother are added in the one-stage roughing; in the two-stage scavenging, 100 - 300 g / t·raw ore of collector is added in each scavenging, and 5 - 20 g / t·raw ore of frother is also added in the first scavenging; in the at least two-stage cleaning, 0 - 100 g / t·raw ore of collector is added in each cleaning, and 5 - 10 g / t·raw ore of frother is also added in the first cleaning.

9. A combined beneficiation method for low-grade and high-slime fine-grained tin tailings according to any one of claims 5 to 8, characterized in that: The collector is any one of butyl xanthate, benzohydroxamic acid and BY9; the activator is copper sulfate or lead nitrate; the frother is No. 2 oil.

10. A combined beneficiation method for low-grade fine-grained tin tailings with high clay content according to claim 1, characterized in that: The gravity separation equipment in step (4) includes a suspension vibration concentrator, a centrifugal concentrator or a high-frequency shaking table.

Images