A beneficiation method for recovering cassiterite from shaking table tailings

Abstract

The present invention relates to the field of mineral beneficiation and processing technology, and more particularly to a beneficiation method for recovering cassiterite from shaking table tailings. The beneficiation method comprises: screening and grading the shaking table tailings to obtain an oversize coarse product and an undersize fine product; grading the undersize fine product in a cyclone to obtain a cyclone coarse grit and a cyclone fine overflow; subjecting the cyclone coarse grit to tin flotation to obtain a flotation 1 tin concentrate; subjecting the flotation 1 tin concentrate to shaking table gravity separation to obtain a shaking table tin concentrate; subjecting the cyclone fine overflow to reverse flotation to remove floatable matter; subjecting the reverse flotation tailings to tin flotation to obtain a flotation 2 tin concentrate; subjecting the flotation 2 tin concentrate to centrifugal gravity separation to obtain a centrifugal tin concentrate and centrifugal tailings; and combining the shaking table tin concentrate and the centrifugal tin concentrate to form a final tin concentrate. The method can significantly reduce tin flotation costs and improve the grade and recovery rate of tin concentrate.

Description

Technical Field

[0001] The invention relates to the technical field of mineral beneficiation and processing, and in particular to a beneficiation method for recovering cassiterite from shaking table tailings. Background Art

[0002] Tin plays an important role in the advancement of information industrialization and is an indispensable metal in electronic industrial components. Therefore, efficiently developing existing tin resources and improving tin utilization efficiency are important measures to ensure my country's tin security.

[0003] Shaking table gravity separation remains the primary method for cassiterite recovery. Firstly, cassiterite's high specific gravity makes it easy to separate from gangue minerals such as quartz, feldspar, and tourmaline. Secondly, gravity separation costs are very low, at one-tenth of flotation, or even less. Furthermore, gravity separation requires a coarser grinding fineness, further reducing grinding costs. However, shaking table gravity separation is ineffective for recovering finer-grained cassiterite, particularly the -0.038mm size. Cassiterite is inherently brittle, and even coarse grinding cannot avoid over-grinding. Currently, flotation is generally used to recover cassiterite in the -0.038mm size range, but flotation costs are prohibitive. When tin prices drop too low or the feed tin grade is low, tin flotation operations are forced to cease, rendering this portion of the tin resource unusable. Furthermore, flotation struggles to produce high-grade tin concentrates, yielding only sub-concentrates with tin grades below 10%, reducing the tin's value. Furthermore, tin is typically smelted in a centralized location, increasing transportation costs and further increasing the pressure on flotation. For example, Chinese patent application CN112547326A discloses a method for recovering tin from low-grade tin tailings. The tin tailings are pulped and then classified in a cyclone. After classification, the +0.045mm particle size is ground to 100% of the -0.015mm particle size. The -0.045mm product after classification is then combined with the -0.015mm product after grinding for pre-enrichment. The enriched concentrate is then subjected to flotation to remove impurities containing calcium, followed by water rinsing, drug removal, and concentration. However, this method for cassiterite flotation only yields a medium-rich ore product with a tin grade greater than 5%.

[0004] Currently, tin prices are generally high, and the benefits of cassiterite flotation can cover the high flotation costs. However, if tin prices drop or the feed tin grade decreases, the benefits will be difficult to cover the flotation costs. Therefore, it is essential to develop a beneficiation method for recovering cassiterite from shaker tailings that can reduce tin recovery costs and improve tin concentrate grade and recovery rate to cope with changes in the tin market and resources. Summary of the Invention

[0005] In response to the current problems of high tin flotation cost, low tin concentrate grade, strong ore mud interference and low tin concentrate recovery rate, the present invention proposes a beneficiation method for recovering cassiterite from shaking table tailings. The present invention adopts the process of "screening classification-cyclone classification-coarse particle flotation + shaking table-fine particle reverse flotation + flotation + centrifugation" to recover cassiterite from shaking table tailings. This method can significantly reduce the cost of tin flotation and improve the grade and recovery rate of tin concentrate.

[0006] The technical solution of the present invention is:

[0007] A beneficiation method for recovering cassiterite from shaking table tailings comprises the following steps:

[0008] S1: Screening the shaker tailings to obtain coarse-grained products on the sieve and fine-grained products under the sieve;

[0009] S2: The fine particles under the screen are classified by cyclone to obtain cyclone coarse sand settling and cyclone fine overflow;

[0010] S3: adding flotation reagents to the coarse sediment in the cyclone to carry out tin flotation operation. The tin flotation operation includes tin flotation roughing operation, tin cleaning operation and tin scavenging operation to obtain flotation 1 tin concentrate;

[0011] S4: The flotation 1 tin concentrate is sent to the shaking table re-selection process to obtain shaking table tin concentrate and shaking table tin middlings;

[0012] S5: adding flotation reagents to the cyclone fine particle overflow obtained in S2 to perform reverse flotation operation to obtain reverse flotation concentrate and reverse flotation tailings;

[0013] S6: adding flotation reagents to the reverse flotation tailings to carry out tin flotation operation, the tin flotation operation includes tin flotation roughing operation, tin cleaning operation and tin scavenging operation to obtain flotation 2 tin concentrate;

[0014] S7: The flotation 2 tin concentrate is subjected to a centrifugal gravity separation operation to obtain a centrifugal tin concentrate.

[0015] Aiming at the problems existing in the recovery of cassiterite from shaking table tailings, such as low feed tin grade, large difference in tin grade among different particle sizes, low tin recovery rate, high tin flotation cost and high tin recovery cost, which lead to the difficulty in efficiently recycling and utilizing these tin resources, the present invention obtains tin-containing products with different particle sizes and properties by screening and grading the shaking table tailings and grading them in a cyclone. Targeted adaptation processes are adopted for tin products of different particle sizes, and tin pre-enrichment is achieved through the "tin flotation-shaking table gravity separation" and "reverse flotation-tin flotation-centrifugal gravity separation" processes. Specifically, the present invention can pre-remove the coarse particles with low tin grade and extremely poor flotation recovery effect in the shaking table tailings through screening and classification; obtain the fine particles with higher tin grade under the screen and enter the cyclone for further classification to obtain the coarse particles sediment of the cyclone and the fine particles overflow of the cyclone; the coarse particles sediment of the cyclone that are easy to float and have low ore slime content are subjected to tin flotation operation to obtain the flotation 1 tin concentrate with a tin grade of about 10% through tin flotation; the flotation 1 tin concentrate is subjected to shaking table gravity separation to obtain the tin grade of 10%. The tin content of the cyclone is increased to more than 30% to obtain a high-grade shaking table tin concentrate; the cyclone fine particles that are difficult to float and have a high slime content are subjected to reverse flotation and tin flotation operations to obtain a higher-grade flotation 2 tin concentrate; the tin grade of the flotation 2 tin concentrate is increased to more than 20% by centrifugal gravity separation to obtain a high-grade centrifugal tin concentrate; finally, products with different properties and particle size properties are obtained through classification and separation, and combined with an adapted process, the low-cost and efficient recovery of cassiterite in the shaking table tailings is achieved.

[0016] The present invention converts wide-grade tin tailings into narrow-grade tin tailings by coordinating multiple classification processes, and then cooperates with the process most suitable for the particle size. According to the principle of first ensuring the recovery rate and then improving the quality, the present invention realizes the efficient recovery of low-grade tin in the shaking table tailings through classification, grading and quality-differentiation treatment, and finally obtains a high-grade, high-recovery tin concentrate product. Not only high-grade tin concentrate is obtained, but also the tin flotation cost is significantly reduced, providing a practical method for the development and utilization of such tin resources in the beneficiation plant, not only avoiding the waste of resources, but also significantly improving the efficiency of the beneficiation plant.

[0017] Furthermore, the screening particle size in step S1 is 0.074-0.15 mm.

[0018] Furthermore, in step S2, the cyclone classification particle size is 0.038-0.043 mm.

[0019] Furthermore, in step S3, flotation reagent is added to the coarse sand in the cyclone and stirred for 10-15 minutes before tin flotation operation is performed.

[0020] Furthermore, the flotation reagents in step S3 are flotation reagent A and flotation reagent B, wherein flotation reagent A is a mixture of dihydroxybenzohydroxamic acid, 1-hydroxy-2-naphthohydroxamic acid, and lead nitrate in a mass ratio of (5-10):(1-2):(3-6); and flotation reagent B is a mixture of water glass, aluminum sulfate, or ferric sulfate in a mass ratio of 3-5:1. The present invention preferably uses flotation reagent A, which has good capture capacity for tin minerals and is less likely to cause coarse particles to fall off during flotation, making it easier to separate the tin minerals, thereby improving the recovery rate of the tin minerals.

[0021] Furthermore, the dihydroxybenzohydroxamic acid is 3,4-dihydroxybenzohydroxamic acid.

[0022] Furthermore, the tin flotation operation in step S3 includes a tin flotation roughing operation, a tin concentration 1 operation, a tin concentration 2 operation, a tin concentration 3 operation, and a tin scavenging operation; during the tin flotation roughing operation, a flotation reagent A is added in an amount of 800-1200 g / t; during the tin concentration 2 operation, a flotation reagent B is added in an amount of 400-800 g / t, and during the tin scavenging operation, a flotation reagent A is added in an amount of 200-300 g / t.

[0023] Furthermore, the shaker in step S4 is a fine particle shaker with a frequency of 300-320 r / min and a stroke of 8-12 mm.

[0024] Furthermore, the flotation reagent in step S5 is a mixture of oleic acid, pine oil and butyl xanthate in a mass ratio of (8-10):1:(5-8).

[0025] Furthermore, the reverse flotation operation in step S5 includes reverse flotation roughing operation, reverse flotation cleaning operation and reverse flotation scavenging operation; during the reverse flotation roughing operation, a flotation agent in an amount of 100-150 g / t is added; during the reverse flotation scavenging operation, a flotation agent in an amount of 20-30 g / t is added.

[0026] Furthermore, in step S6, the flotation reagents are flotation reagent D and flotation reagent E, wherein flotation reagent D is a mixture of water glass, sulfuric acid or oxalic acid in a mass ratio of 3-5:1; and flotation reagent E is a mixture of styrenephosphonic acid, 1,4-phenylenediphosphonic acid and lead nitrate in a mass ratio of (5-10):(2-5):(2-6). The present invention preferably uses the above-mentioned flotation reagent E, which utilizes the -PO(OH)2- group (styrenephosphonic acid and 1,4-phenylenediphosphonic acid in flotation reagent E) to react with Sn. 4+ The coordination to form a stable complex and the -NH- group has an electrostatic adsorption force on tin ore, but a weak adsorption force on ore mud, ensuring the efficient enrichment and recovery of tin at a low dosage.

[0027] Furthermore, the tin flotation operation in step S6 includes a tin flotation roughing operation, a tin concentration 1 operation, a tin concentration 2 operation, a tin concentration 3 operation, and a tin scavenging operation; during the tin flotation roughing operation, a flotation agent D in an amount of 1000-1500 g / t and a flotation agent E in an amount of 600-800 g / t are added; during the tin concentration 2 operation, a flotation agent D in an amount of 400-800 g / t is added; and during the tin scavenging operation, a flotation agent E in an amount of 150-200 g / t is added.

[0028] Furthermore, in step S6, flotation reagent is added to the reverse flotation tailings and stirred for 30-45 minutes before tin flotation operation is performed.

[0029] Furthermore, the centrifugal gravity separation operation in step S7 includes a centrifugal roughing operation, a centrifugal cleaning operation 1 and a centrifugal cleaning operation 2. The centrifugal acceleration during the centrifugal roughing operation is 55-65G; the centrifugal acceleration during the centrifugal cleaning operation 1 is 45-55G; and the centrifugal acceleration during the centrifugal cleaning operation 2 is 35-45G.

[0030] Furthermore, the feed concentration in step S7 is 20-25%.

[0031] Furthermore, in step S7, the single feeding time is 45-60 seconds; the single flushing time is 5-10 seconds.

[0032] Compared with the prior art, the present invention has the following advantages:

[0033] (1) The present invention obtains tin-containing products with different particle sizes and properties by screening and grading the shaking table tailings and grading them by a cyclone. Adaptive processes are used in a targeted manner for tin products of different particle sizes. Tin pre-enrichment is achieved through the "tin flotation-shaking table gravity separation" and "reverse flotation-tin flotation-centrifugal gravity separation" processes, respectively, thereby achieving low-cost and high-efficiency recovery of cassiterite in the shaking table tailings, and ultimately obtaining a high-grade, high-recovery tin concentrate product. Not only is a high-grade tin concentrate obtained, but the cost of tin flotation is also significantly reduced, providing a practical method for the development and utilization of such tin resources in the concentrator, not only avoiding the waste of resources, but also significantly improving the efficiency of the concentrator.

[0034] (2) The screening and pre-tailing of the present invention significantly reduces the amount of tin flotation selected, and the screening and grading greatly reduces the flotation equipment and flotation costs, while preventing the problem of tin flotation sedimentation tanks; after cyclone classification, the high-mud difficult-to-float tin material is divided into two categories: low-mud easy-to-float tin material and high-mud difficult-to-float tin material, which reduces the interference of fine-grained ore mud on easy-to-float cassiterite and improves the cassiterite recovery rate; according to the differences in the properties of different materials, a high-capturing collector (flotation agent A) is used for flotation of low-mud materials, and an anti-mud interference collector (flotation agent B) is used for high-mud materials. By adopting different reagent systems and processes, the cassiterite is recovered by quality classification, achieving the purpose of non-interference, and obtaining flotation tin concentrate products of different grades.

[0035] (3) The present invention aims at the flotation concentrate of moderate grade obtained by different flotation processes, and further adopts different gravity separation processes to improve the flotation grade, which effectively solves the shortcoming of the small processing capacity of the two gravity separation equipments. At the same time, the processing particle size is changed from a wide particle size to a narrow particle size, which significantly improves the processing efficiency and capacity.

[0036] (4) The present invention adopts a flotation-gravity combined process to give full play to the advantages of each process. The primary task of flotation is to ensure the recovery rate of cassiterite, and gravity separation is to improve the grade. Taking advantage of the characteristics of high enrichment ratio and low recovery rate of shaking table gravity separation, the low-grade shaking table middlings are returned to tin flotation to avoid the loss of recovery rate. Taking advantage of the characteristics of low enrichment ratio but high recovery rate of centrifugal gravity separation, an open-circuit centrifugal gravity separation process is adopted (that is, the tailings of each operation are discarded and no longer returned to a certain operation, and the concentrate continues to the next operation or is used as a product), which further removes low-grade high-mud materials, realizes the cyclic enrichment of low-mud and high-tin materials and the secondary discarding of low-tin and high-mud materials.

[0037] (5) The process of the present invention has strong adaptability and can be optimized and adjusted according to the particle size products in the shaking table tailings. By reducing a certain operation or increasing the number of a certain operation, the recovery of cassiterite in the shaking table tailings of different tin concentrators can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 1 is a process flow chart of the ore dressing method for recovering cassiterite from shaking table tailings adopted in Examples 1-3 of the present invention. DETAILED DESCRIPTION

[0039] The present invention is further described below with reference to specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art.

[0040] In the following examples, the pharmaceutical agents used are all commercially available products. Unless otherwise specified, the percentages in each example are by mass.

[0041] Example 1: A beneficiation method for recovering cassiterite from shaking table tailings

[0042] The test sample is a shaker gravity separation tailings from a high-silver tin polymetallic mine in Inner Mongolia, in which the tin grade is 0.38%. Silicate minerals such as tourmaline, quartz, and mica are the main gangue minerals, of which the content of -0.074mm particle size is 58%. The beneficiation method for recovering cassiterite from the shaker tailings is as follows: Figure 1 The main steps are as follows:

[0043] S1 screening and grading operations

[0044] The shaker tailings are fed into a high-frequency vibrating screen with a mesh size of 0.074 mm to obtain a coarse particle product on the +0.074 mm sieve and a fine particle product under the -0.074 mm sieve;

[0045] S2 cyclone classification operation

[0046] - The fine-grained product under the 0.074mm sieve is classified into 0.038mm particle size using a cyclone to obtain cyclone coarse sand settling and cyclone fine overflow;

[0047] S3 tin flotation 1 operation

[0048] 800 g / t of flotation reagent A is added to the obtained coarse sediment from the cyclone, and after stirring for 10 minutes, the mixture enters the tin flotation roughing operation to obtain tin rougher concentrate and tin rougher tailings; the tin rougher concentrate enters the tin concentrating operation 1 to obtain tin concentrating 1 concentrate and concentrating 1 tailings; 400 g / t of flotation reagent B is added to the obtained tin concentrating 1 concentrate, and the mixture enters the tin concentrating 2 operation to obtain tin concentrating 2 concentrate and concentrating 2 tailings; the obtained tin concentrating 2 concentrate enters the tin concentrating 3 operation to obtain flotation 1 tin concentrate and concentrating 3 tailings; 200 g / t of flotation reagent A is added to the tin rougher tailings, and the mixture enters the tin scavenging operation to obtain tin scavenging concentrate and tin scavenging tailings (tin tailings 1); the concentrating 1 tailings and tin scavenging concentrate are returned to the tin flotation roughing operation, the concentrating 2 tailings are returned to the tin concentrating 1 operation, and the concentrating 3 tailings are returned to the tin concentrating 2 operation;

[0049] S4 shaking table re-selection operation

[0050] The flotation 1 tin concentrate obtained in step S3 is fed into a shaking table for reselection. The shaking table specification is a fine-grained shaking table. The shaking table stroke frequency is adjusted to 300 r / min and the stroke distance is 8 mm to obtain the shaking table tin concentrate and the shaking table tin middlings. The shaking table tin middlings are returned to the tin flotation roughing operation in step S3.

[0051] S5 reverse flotation operation

[0052] Add 100 g / t of flotation reagent C to the cyclone fine particle overflow obtained in step S2, and after stirring, enter the reverse flotation roughing operation to obtain reverse flotation roughing concentrate and reverse flotation roughing tailings; the reverse flotation roughing concentrate enters the reverse flotation cleaning operation to obtain reverse flotation cleaned concentrate and reverse flotation cleaned tailings; add 20 g / t of flotation reagent C to the reverse flotation roughing tailings, and then enter the reverse flotation scavenging operation to obtain reverse flotation scavenging concentrate and reverse flotation scavenging tailings; the reverse flotation cleaned tailings and the reverse flotation scavenging concentrate are returned together to the reverse flotation roughing operation to finally obtain reverse flotation concentrate and reverse flotation tailings;

[0053] S6 Tin Flotation 2 Operation

[0054] 1000 g / t of flotation reagent D and 600 g / t of flotation reagent E are added to the reverse flotation tailings obtained in step S5, and after stirring for 30 minutes, the tin roughing flotation process is carried out to obtain a tin roughing concentrate and a tin roughing tailing. The tin roughing concentrate is carried out to the tin concentrating process 1 to obtain a tin concentrating concentrate 1 and a concentrating tailing 1. 400 g / t of flotation reagent D is added to the obtained tin concentrating concentrate 1, and the tin concentrating process is carried out to obtain a tin concentrating concentrate 2 and a concentrating tailing 2. The obtained tin concentrating concentrate 2 is carried out to the tin concentrating process 3 to obtain a flotation 2 tin concentrate and a concentrating tailing 3. 150 g / t of flotation reagent E is added to the tin roughing tailings, and the tin scavenging process is carried out to obtain a tin scavenging concentrate and a tin scavenging tailing. The concentrating tailing 1 and the tin scavenging concentrate are returned to the tin roughing flotation process, the concentrating tailing 2 is returned to the tin concentrating process 1, and the concentrating tailing 3 is returned to the tin concentrating process 2.

[0055] S7 centrifugal gravity separation process

[0056] After the flotation 2 tin concentrate obtained in step S6 is slurried to a concentration of 20%, the centrifugal force is adjusted to 55G and a centrifugal roughing operation is performed, with a single feeding time of 45 seconds and a single flushing time of 5 seconds, to obtain a centrifugal roughing concentrate and roughing tailings. The centrifugal roughing concentrate then proceeds to centrifugal concentration 1 at a centrifugal acceleration of 45G, to obtain a centrifugal concentration 1 concentrate and a centrifugal concentration 1 tailings. The centrifugal concentration 1 concentrate then proceeds to centrifugal concentration 2 at a centrifugal acceleration of 35G, to obtain a centrifugal tin concentrate and a centrifugal concentration 2 tailings. The roughing tailings, centrifugal concentration 1 tailings, and centrifugal concentration 2 tailings are combined to form the centrifugal tailings. The centrifugal tailings and the tin scavenging tailings obtained in step S6 are combined to form tin tailings 2. The centrifugal tin concentrate and the shaking table tin concentrate obtained in step S4 are combined to form the final tin concentrate.

[0057] Finally, a shaking tin concentrate with a tin grade of 33.54% and a recovery rate of 45.01% and a centrifugal tin concentrate with a tin grade of 21.86% and a recovery rate of 29.43% were obtained, resulting in a tin concentrate with a comprehensive tin grade of 27.69% and a total tin recovery rate of 74.44%.

[0058] Example 2: A beneficiation method for recovering cassiterite from shaking table tailings

[0059] The test sample is a tin-polymetallic mine tailings from a shaking table in Gejiu, Yunnan. The tin grade is 0.56%, and silicate minerals such as feldspar, quartz, and chlorite are the main gangue minerals. The content of the -0.15 mm particle size is 68%. The ore dressing method for recovering cassiterite from the shaking table tailings is as follows: Figure 1 The main steps are as follows:

[0060] S1 screening and grading operations

[0061] The shaker tailings are fed into a high-frequency vibrating screen with a mesh size of 0.10 mm to obtain a coarse particle product on the +0.1 mm sieve and a fine particle product under the -0.1 mm sieve;

[0062] S2 cyclone classification operation

[0063] - The fine-grained product under the 0.1mm sieve is classified into 0.038mm particle size using a cyclone to obtain the cyclone coarse-grained sand settling and the cyclone fine-grained overflow;

[0064] S3 tin flotation 1 operation

[0065] 1200 g / t of flotation reagent A is added to the obtained coarse sediment from the cyclone, and after stirring for 15 minutes, it enters the tin flotation roughing operation to obtain tin roughing concentrate and tin roughing tailings; the tin roughing concentrate enters the tin concentrating operation 1 to obtain tin concentrating 1 concentrate and concentrating 1 tailings; 800 g / t of flotation reagent B is added to the obtained tin concentrating 1 concentrate, and then enters the tin concentrating operation 2 to obtain tin concentrating 2 concentrate and concentrating 2 tailings; the obtained tin concentrating 2 concentrate enters the tin concentrating 3 operation to obtain flotation 1 tin concentrate and concentrating 3 tailings; 300 g / t of flotation reagent A is added to the tin roughing tailings, and then enters the tin scavenging operation to obtain tin scavenging concentrate and tin scavenging tailings (tin tailings 1); the concentrating 1 tailings and tin scavenging concentrate are returned to the tin flotation roughing operation, the concentrating 2 tailings are returned to the tin concentrating 1 operation, and the concentrating 3 tailings are returned to the tin concentrating 2 operation;

[0066] S4 shaking table re-selection operation

[0067] The flotation 1 tin concentrate obtained in step S3 is fed into a shaking table for re-selection. The shaking table specification is a fine-grained shaking table. The shaking table stroke frequency is adjusted to 320 r / min and the stroke distance is 12 mm to obtain the shaking table tin concentrate and the shaking table tin middlings. The shaking table tin middlings are returned to the tin flotation roughing operation in step S3.

[0068] S5 reverse flotation operation

[0069] Add 150 g / t of flotation reagent C to the cyclone fine particle overflow obtained in step S2, and after stirring, enter the reverse flotation roughing operation to obtain reverse flotation roughing concentrate and reverse flotation roughing tailings; the reverse flotation roughing concentrate enters the reverse flotation cleaning operation to obtain reverse flotation cleaned concentrate and reverse flotation cleaned tailings; add 30 g / t of flotation reagent C to the reverse flotation roughing tailings, and then enter the reverse flotation scavenging operation to obtain reverse flotation scavenging concentrate and reverse flotation scavenging tailings; the reverse flotation cleaned tailings and the reverse flotation scavenging concentrate are returned together to the reverse flotation roughing operation to finally obtain reverse flotation concentrate and reverse flotation tailings;

[0070] S6 Tin Flotation 2 Operation

[0071] 1500 g / t of flotation reagent D and 800 g / t of flotation reagent E are added to the reverse flotation tailings obtained in step S5. After stirring for 45 minutes, the tailings are subjected to a tin flotation roughing operation to obtain a tin rougher concentrate and a tin rougher tailings. The tin rougher concentrate is subjected to a tin beneficiation operation 1 to obtain a tin beneficiation 1 concentrate and a beneficiation 1 tailings. 800 g / t of flotation reagent D is added to the obtained tin beneficiation 1 concentrate and then subjected to a tin beneficiation 2 operation to obtain a tin beneficiation 2 concentrate and a beneficiation 2 tailings. The obtained tin beneficiation 2 concentrate is subjected to a tin beneficiation 3 operation to obtain a flotation 2 tin concentrate and a beneficiation 3 tailings. 200 g / t of flotation reagent E is added to the tin rougher tailings and then subjected to a tin scavenging operation to obtain a tin scavenging concentrate and a tin scavenging tailings. The beneficiation 1 tailings and the tin scavenging concentrate are returned to the tin flotation roughing operation, the beneficiation 2 tailings are returned to the tin beneficiation 1 operation, and the beneficiation 3 tailings are returned to the tin beneficiation 2 operation.

[0072] S7 centrifugal gravity separation process

[0073] After the flotation 2 tin concentrate obtained in step S6 is slurried to a concentration of 25%, the centrifugal force is adjusted to 65G for centrifugal roughing, with a single feed time of 55s and a single rinse time of 10s, to produce centrifugal rougher concentrate and rougher tailings. The centrifugal rougher concentrate then proceeds to centrifugal concentration 1 at a centrifugal acceleration of 55G, producing centrifugal concentration 1 concentrate and centrifugal concentration 1 tailings. The centrifugal concentration 1 concentrate then proceeds to centrifugal concentration 2 at a centrifugal acceleration of 45G, producing centrifugal tin concentrate and centrifugal concentration 2 tailings. The rougher tailings, centrifugal concentration 1 tailings, and centrifugal concentration 2 tailings are combined to form centrifugal tailings. The centrifugal tailings and the tin scavenging tailings obtained in step S6 are combined to form tin tailings 2. The centrifugal tin concentrate and the shaking table tin concentrate obtained in step S4 are combined to form the final tin concentrate.

[0074] Finally, a shaking tin concentrate with a tin grade of 36.85% and a recovery rate of 61.20% and a centrifugal tin concentrate with a tin grade of 23.54% and a recovery rate of 20.93% were obtained, resulting in a tin concentrate with a comprehensive tin grade of 32.21% and a total tin recovery rate of 82.13%.

[0075] Example 3: A beneficiation method for recovering cassiterite from shaking table tailings

[0076] The test sample is a tin-concentrating tailings from a copper-tin polymetallic mine in Ximeng, Inner Mongolia. The tin grade is 0.29%. Silicate minerals such as feldspar, tourmaline, chlorite, and mica are the main gangue minerals, of which the content of -0.15mm particle size is 63%. The ore dressing method for recovering cassiterite from the tin-concentrating tailings is as follows: Figure 1 The main steps are as follows:

[0077] S1 screening and grading operations

[0078] The shaker tailings are fed into a high-frequency vibrating screen with a mesh size of 0.15 mm to obtain a coarse particle product on the +0.15 mm sieve and a fine particle product under the -0.15 mm sieve;

[0079] S2 cyclone classification operation

[0080] - The fine-grained product under the 0.15mm sieve is classified into 0.043mm particle size using a cyclone to obtain the cyclone coarse sand settling and cyclone fine overflow;

[0081] S3 tin flotation 1 operation

[0082] Add 1000 g / t of flotation reagent A to the coarse sediment obtained from the cyclone, stir for 15 minutes, and then enter the tin flotation roughing operation to obtain tin roughing concentrate and tin roughing tailings; the tin roughing concentrate enters the tin concentrating operation 1 to obtain tin concentrating 1 concentrate and concentrating 1 tailings; add 500 g / t of flotation reagent B to the obtained tin concentrating 1 concentrate and enter the tin concentrating 2 operation to obtain tin concentrating 2 concentrate and concentrating 2 tailings; the obtained tin concentrating 2 concentrate enters the tin concentrating 3 operation to obtain flotation 1 tin concentrate and tin concentrating 3 tailings; add 250 g / t of flotation reagent A to the tin roughing tailings and enter the tin scavenging operation to obtain tin scavenging concentrate and tin scavenging tailings (tin tailings 1); the concentrating 1 tailings and tin scavenging concentrate are returned to the tin flotation roughing operation, the concentrating 2 tailings are returned to the tin concentrating 1 operation, and the concentrating 3 tailings are returned to the tin concentrating 2 operation;

[0083] S4 shaking table re-selection operation

[0084] The flotation 1 tin concentrate obtained in step S3 is fed into a shaking table for re-selection. The shaking table specification is a fine-grained shaking table with a shaking frequency of 320 r / min and a stroke distance of 10 mm to obtain a shaking table tin concentrate and a shaking table tin middlings. The shaking table tin middlings are returned to the tin flotation roughing operation in step S3.

[0085] S5 reverse flotation operation

[0086] Add 120 g / t of flotation reagent C to the cyclone fine particle overflow obtained in step S2, stir the mixture, and then enter the reverse flotation roughing operation to obtain reverse flotation roughing concentrate and reverse flotation roughing tailings; the reverse flotation roughing concentrate enters the reverse flotation cleaning operation to obtain reverse flotation cleaned concentrate and reverse flotation cleaned tailings; add 20 g / t of flotation reagent C to the reverse flotation roughing tailings, and then enter the reverse flotation scavenging operation to obtain reverse flotation scavenging concentrate and reverse flotation scavenging tailings; the reverse flotation cleaned tailings and the reverse flotation scavenging concentrate are returned together to the reverse flotation roughing operation to finally obtain reverse flotation concentrate and reverse flotation tailings;

[0087] S6 Tin Flotation 2 Operation

[0088] 1500 g / t of flotation reagent D and 800 g / t of flotation reagent E are added to the reverse flotation tailings obtained in step S5. After stirring for 45 minutes, the tailings are subjected to a tin flotation roughing operation to obtain a tin rougher concentrate and a tin rougher tailings. The tin rougher concentrate is subjected to a tin beneficiation operation 1 to obtain a tin beneficiation 1 concentrate and a beneficiation 1 tailings. 600 g / t of flotation reagent D is added to the obtained tin beneficiation 1 concentrate and the tailings are subjected to a tin beneficiation 2 operation to obtain a tin beneficiation 2 concentrate and a beneficiation 2 tailings. The obtained tin beneficiation 2 concentrate is subjected to a tin beneficiation 3 operation to obtain a flotation 2 tin concentrate and a beneficiation 3 tailings. 200 g / t of flotation reagent E is added to the tin rougher tailings and the tailings are subjected to a tin scavenging operation to obtain a tin scavenging concentrate and a tin scavenging tailings. The beneficiation 1 tailings and the tin scavenging concentrate are returned to the tin flotation roughing operation, the beneficiation 2 tailings are returned to the tin beneficiation 1 operation, and the beneficiation 3 tailings are returned to the tin beneficiation 2 operation.

[0089] (7) Centrifugal gravity separation

[0090] After the flotation 2 tin concentrate obtained in step S6 is slurried to a concentration of 25%, the centrifugal force is adjusted to 65G for centrifugal roughing, with a single feed time of 55s and a single rinse time of 10s, to produce centrifugal rougher concentrate and rougher tailings. The centrifugal rougher concentrate then proceeds to centrifugal concentration 1 at a centrifugal acceleration of 55G, producing centrifugal concentration 1 concentrate and centrifugal concentration 1 tailings. The centrifugal concentration 1 concentrate then proceeds to centrifugal concentration 2 at a centrifugal acceleration of 45G, producing centrifugal tin concentrate and centrifugal concentration 2 tailings. The rougher tailings, centrifugal concentration 1 tailings, and centrifugal concentration 2 tailings are combined to form centrifugal tailings. The centrifugal tailings and the tin scavenging tailings obtained in step S6 are combined to form tin tailings 2. The centrifugal tin concentrate and the shaking table tin concentrate obtained in step S4 are combined to form the final tin concentrate.

[0091] Finally, a shaking table tin concentrate with a tin grade of 31.85% and a recovery rate of 52.72% and a centrifugal tin concentrate with a tin grade of 21.87% and a recovery rate of 24.63% were obtained, with a comprehensive tin grade of 27.81% and a total tin recovery rate of 77.35%.

[0092] The test sample is the same as that in Example 1, which is a shaking table gravity separation tailings of a high-silver-tin polymetallic mine in Inner Mongolia, wherein the tin grade is 0.38% and the content of the -0.074 mm particle size is 58%.

[0093] The main steps of the ore dressing method for recovering cassiterite from shaking table tailings are as follows:

[0094] S1 cyclone classification operation

[0095] Use cyclone to remove mud and obtain cyclone sand settling and overflow;

[0096] The obtained grit had a yield of 72.02%, a tin grade of 0.80%, and a tin recovery rate of 70.13%, and the overflow had a yield of 27.98%, a tin grade of 0.60%, and a tin recovery rate of 29.87%;

[0097] S2 cassiterite flotation operation

[0098] 800 g / t of flotation reagent A is added to the obtained cyclone sediment, and after stirring for 10 minutes, it enters the tin flotation roughing operation to obtain tin roughing concentrate and tin roughing tailings; the tin roughing concentrate enters the tin concentrating operation 1 to obtain tin concentrating 1 concentrate and concentrating 1 tailings; 400 g / t of flotation reagent B is added to the obtained tin concentrating 1 concentrate, and then enters the tin concentrating operation 2 to obtain tin concentrating 2 concentrate and concentrating 2 tailings; the obtained tin concentrating 2 concentrate enters the tin concentrating 3 operation to obtain flotation tin concentrate and concentrating 3 tailings; 200 g / t of flotation reagent A is added to the tin roughing tailings, and then enters the tin scavenging operation to obtain tin scavenging concentrate and tin scavenging tailings; the concentrating 1 tailings and tin scavenging concentrate are returned to the tin flotation roughing operation, the concentrating 2 tailings are returned to the tin concentrating 1 operation, and the concentrating 3 tailings are returned to the tin concentrating 2 operation;

[0099] S3 cassiterite shaking table for gravity separation

[0100] The flotation tin concentrate obtained in step S2 is fed into a shaking table for re-selection, and the stroke frequency is adjusted to 320 r / min and the stroke distance is 10 mm to obtain shaking table tin concentrate and shaking table tin middlings;

[0101] Finally, the "deslime removal-tin flotation-tin gravity separation process" was used to obtain tin concentrate with a tin grade of 26.58% and a recovery rate of 40.03%, and tin middlings with a tin grade of 2.78% and a recovery rate of 22.34%.

[0102] Comparative Example 2: A beneficiation method for recovering cassiterite from shaking table tailings

[0103] The test sample is the same as that in Example 1, which is a shaking table gravity separation tailings of a high-silver-tin polymetallic mine in Inner Mongolia, wherein the tin grade is 0.38% and the content of the -0.074 mm particle size is 58%.

[0104] The beneficiation method for recovering cassiterite from shaking table tailings is similar to that in Example 1;

[0105] The difference from Example 1 is that the reagent used in the tin flotation operation 2 is replaced with the same type of reagent as that used in the tin flotation operation 1, as shown in Table 1.

[0106] Finally, a shaking tin concentrate with a tin grade of 33.54% and a recovery rate of 45.01% and a centrifugal tin concentrate with a tin grade of 16.75% and a recovery rate of 21.67% were obtained, resulting in a tin concentrate with a comprehensive tin grade of 25.29% and a total tin recovery rate of 66.68%.

[0107] Comparative Example 3: A beneficiation method for recovering cassiterite from shaking table tailings

[0108] The test sample is the same as that in Example 1, which is a shaking table gravity separation tailings of a high-silver-tin polymetallic mine in Inner Mongolia, wherein the tin grade is 0.38% and the content of the -0.074 mm particle size is 58%.

[0109] The beneficiation method for recovering cassiterite from shaking table tailings is similar to that in Example 1;

[0110] The difference from Example 1 is that the reagent used in tin flotation operation 1 was replaced with the same type of reagent as used in tin flotation operation 2, as shown in Table 1. The resulting tin concentrate had a tin grade of 32.75% and a recovery rate of 34.92%, and a centrifugal tin concentrate had a tin grade of 21.86% and a recovery rate of 29.43%. The total tin grade was 26.67%, and the total tin recovery rate was 64.35%.

[0111] The types of drugs and their proportions in the examples and comparative examples are shown in Table 1.

[0112] Table 1 Types and proportions of medicines in Examples and Comparative Examples

[0113]

[0114]

[0115] Comparative Example 1 used a conventional tin flotation process (desliming-tin flotation-tin gravity separation) to recover tin from the shaker tailings, ultimately yielding a tin concentrate with a tin grade of 26.58% and a recovery rate of 40.03%. In Example 1, the patented beneficiation method of this invention (removal-classification-coarse particle flotation + shaker-fine particle reverse flotation + flotation + centrifugation) was employed, increasing the tin recovery rate by 34.41 percentage points. This new process significantly improves the concentrate tin grade and recovery rate while reducing concentrate yield, flotation processing volume, and reagent usage. This enhances the ability of on-site tin flotation to respond to market and resource fluctuations, ensuring the efficient development and utilization of tin resources.

[0116] In Comparative Example 2, after the reagent of tin flotation 2 was replaced with the same type of reagent as that of tin flotation 1, compared with Example 1, the tin grade of tin recovered from the cyclone overflow, i.e., the centrifugal tin concentrate, decreased from 21.86% to 16.75%, and the tin recovery rate decreased from 29.43% to 21.67%. This shows that after replacing reagent E with reagent A and reagent D with reagent B, the tin index of the fine particle part has significantly deteriorated. Although both are tin flotation, reagents E and D have stronger resistance to fine mud interference.

[0117] In Comparative Example 3, after the reagent of tin flotation 1 was replaced with the same type of reagent of tin flotation 2, compared with Example 1, the tin grade of tin recovered from the cyclone sand settling, i.e., the shaking table tin concentrate, decreased from 33.54% to 32.75%, and the tin recovery rate decreased from 45.01% to 34.92%, indicating that after replacing reagent A with reagent E and reagent B with reagent D, the tin index of the coarse particle part was significantly deteriorated. Although the same tin flotation was used, reagents A and B had better capture properties for low-mud coarse tin.

Claims

1. A beneficiation method for recovering cassiterite from shaking table tailings, characterized in that: The following steps are involved: S1: Screening the shaker tailings to obtain coarse-grained products on the sieve and fine-grained products under the sieve; S2: The fine particles under the screen are classified by cyclone to obtain cyclone coarse sand settling and cyclone fine overflow; S3: adding flotation reagents to the coarse sediment in the cyclone to carry out tin flotation operation. The tin flotation operation includes tin flotation roughing operation, tin cleaning operation and tin scavenging operation to obtain flotation 1 tin concentrate; S4: The flotation 1 tin concentrate is sent to the shaking table re-selection process to obtain shaking table tin concentrate and shaking table tin middlings; S5: adding flotation reagents to the cyclone fine particle overflow obtained in S2 to perform reverse flotation operation to obtain reverse flotation concentrate and reverse flotation tailings; S6: adding flotation reagents to the reverse flotation tailings to carry out tin flotation operation, the tin flotation operation includes tin flotation roughing operation, tin cleaning operation and tin scavenging operation to obtain flotation 2 tin concentrate; S7: The flotation 2 tin concentrate is subjected to a centrifugal gravity separation operation to obtain a centrifugal tin concentrate.

2. The ore dressing method for recovering cassiterite from shaking table tailings according to claim 1, characterized in that: The screening particle size in step S1 is 0.074-0.15 mm.

3. The ore dressing method for recovering cassiterite from shaking table tailings according to claim 1, characterized in that: The cyclone classification particle size in step S2 is 0.038-0.043 mm.

4. The ore dressing method for recovering cassiterite from shaking table tailings according to claim 1, characterized in that: The flotation reagents in step S3 are flotation reagent A and flotation reagent B, wherein the flotation reagent A is a mixture of dihydroxybenzohydroxamic acid, 1-hydroxy-2-naphthohydroxamic acid and lead nitrate in a mass ratio of (5-10):(1-2):(3-6); and the flotation reagent B is a mixture of water glass, aluminum sulfate or ferric sulfate in a mass ratio of 3-5:

1.

5. The ore dressing method for recovering cassiterite from shaking table tailings according to claim 4, characterized in that: The tin flotation operation in step S3 includes a tin flotation roughing operation, a tin concentration 1 operation, a tin concentration 2 operation, a tin concentration 3 operation, and a tin scavenging operation; during the tin flotation roughing operation, a flotation reagent A in an amount of 800-1200 g / t is added; during the tin concentration 2 operation, a flotation reagent B in an amount of 400-800 g / t is added, and during the tin scavenging operation, a flotation reagent A in an amount of 200-300 g / t is added.

6. The ore dressing method for recovering cassiterite from shaking table tailings according to claim 1, characterized in that: The shaker in step S4 is a fine particle shaker with a frequency of 300-320 r / min and a stroke of 8-12 mm.

7. The ore dressing method for recovering cassiterite from shaking table tailings according to claim 1, characterized in that: In step S5, the flotation reagent is a mixture of oleic acid, pine oil and butyl xanthate in a mass ratio of (8-10):1:(5-8).

8. The ore dressing method for recovering cassiterite from shaking table tailings according to claim 1, characterized in that: In step S6, the flotation reagents are flotation reagent D and flotation reagent E, wherein flotation reagent D is a mixture of water glass and sulfuric acid or oxalic acid in a mass ratio of 3-5:1; and flotation reagent E is a mixture of styrenephosphonic acid, 1,4-phenylenediphosphonic acid, and lead nitrate in a mass ratio of (5-10):(2-5):(2-6).

9. The ore dressing method for recovering cassiterite from shaking table tailings according to claim 8, characterized in that: The tin flotation operation in step S6 includes a tin flotation roughing operation, a tin concentration 1 operation, a tin concentration 2 operation, a tin concentration 3 operation, and a tin scavenging operation; during the tin flotation roughing operation, a flotation agent D in an amount of 1000-1500 g / t and a flotation agent E in an amount of 600-800 g / t are added; during the tin concentration 2 operation, a flotation agent D in an amount of 400-800 g / t is added; and during the tin scavenging operation, a flotation agent E in an amount of 150-200 g / t is added.

10. The ore dressing method for recovering cassiterite from shaking table tailings according to claim 1, characterized in that: The centrifugal gravity separation process in step S7 includes a centrifugal roughing process, a centrifugal cleaning process 1 and a centrifugal cleaning process 2. The centrifugal acceleration during the centrifugal roughing process is 55-65G; the centrifugal acceleration during the centrifugal cleaning process 1 is 45-55G; and the centrifugal acceleration during the centrifugal cleaning process 2 is 35-45G.

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