Beneficiation method for recovering cassiterite from table tailings

Abstract

The invention relates to the technical field of mineral beneficiation and processing, in particular to a beneficiation method for recovering cassiterite from table tailings. The beneficiation method comprises the steps that after the table tailings are screened and classified, oversize coarse grain products and undersize fine grain products are obtained; undersize fine grain products are classified through a cyclone, and cyclone coarse grain settled sand and cyclone fine grain overflow are obtained; carrying out tin flotation on coarse settled sand of the cyclone to obtain first-flotation tin concentrate; the first flotation tin concentrate is subjected to shaking table reselection to obtain shaking table tin concentrate; fine particle overflow of the cyclone is subjected to reverse flotation to remove easily floating substances; performing tin flotation on the reverse flotation tailings to obtain flotation secondary tin concentrate; and carrying out centrifugal reselection on the flotation tin concentrate 2 to obtain centrifugal tin concentrate and centrifugal tailings, and combining the table tin concentrate and the centrifugal tin concentrate into final tin concentrate. The method can obviously reduce the tin flotation cost and improve the tin concentrate grade and recovery rate.

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. my country is the world's largest tin consumer, with an external dependence on tin ore of about 30%-40%, and more than 90% of the tin comes from Myanmar. The production cost of Myanmar's tin ore continues to increase, tin ore resources are gradually depleted, and the supply capacity is limited. Due to safety and environmental protection, domestic tin production has also been declining. Therefore, efficient development of existing tin resources and improving tin utilization efficiency are important measures to ensure my country's tin security.

[0003] The shaking table gravity separation is still the main method for cassiterite recovery. On the one hand, cassiterite has a high specific gravity and is easy to separate from gangue minerals such as quartz, feldspar, and tourmaline; on the other hand, the gravity separation cost is very low, only one-tenth of flotation, or even lower. In addition, the grinding fineness required for gravity separation is also coarse, which further reduces the grinding cost. However, the shaking table gravity separation has a poor effect on the recovery of fine-grained cassiterite, especially the -0.038mm particle size. The cassiterite itself is brittle and fragile, and even in the case of coarse grinding, it is impossible to avoid the problem of over-crushing and over-grinding. At present, the recovery of -0.038mm particle size cassiterite is generally recovered by flotation process, but the flotation cost is too high. Once the tin price is too low or the tin grade of the feed ore is low, the tin flotation is forced to stop production, resulting in the inability to further utilize this part of the tin resources. Secondly, it is difficult to obtain high-grade tin concentrate by flotation, and only sub-concentrate products with a tin grade of less than 10% can be obtained, which reduces the value of tin. In addition, tin is generally smelted in a centralized manner in a different place, which also increases the transportation cost and further increases the pressure of flotation. For example, Chinese patent application CN112547326A discloses a method for recovering tin metal from low-grade tin tailings, wherein the tin tailings are pulped and then classified by a cyclone, and after classification, the +0.045mm particle size minerals are ground to -0.015mm, accounting for 100%, and then the -0.045mm product after classification is combined with the -0.015mm product after grinding for pre-enrichment, and the enriched concentrate is subjected to flotation to remove impurities, and after calcium impurities are removed, water is added for rinsing, drug removal, and concentration. However, the method can only obtain a medium-rich ore product with a tin grade greater than 5% for cassiterite flotation.

[0004] At present, the overall tin price is high, and the benefits of cassiterite flotation can cover the high flotation cost. Once the tin price drops or the tin grade of the feed ore decreases, the benefits will be difficult to cover the flotation cost. Therefore, it is necessary to develop a set of ore dressing methods for recovering cassiterite from shaking table tailings that can reduce tin recovery costs, increase tin concentrate grade and recovery rate, in response to changes in the tin market and resources. Summary of the invention

[0005] In view of 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 in shaking table tailings. The method can significantly reduce the tin flotation cost and improve the tin concentrate grade and recovery rate.

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

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

[0008] S1: Screening the shaking table tailings to obtain coarse particles on the screen and fine particles under the screen;

[0009] S2: The fine particles under the screen are classified by a hydrocyclone to obtain the coarse sedimentation of the hydrocyclone and the fine overflow of the hydrocyclone;

[0010] S3: adding flotation reagents to the coarse sediment in the hydrocyclone to carry out tin flotation operation, the tin flotation operation includes tin flotation roughing operation, tin concentrating operation and tin scavenging operation, and obtaining flotation 1 tin concentrate;

[0011] S4: sending the flotation 1 tin concentrate to the shaking table re-selection operation to obtain shaking table tin concentrate and shaking table tin middlings;

[0012] S5: adding flotation reagent 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 operations, wherein the tin flotation operations include tin flotation roughing operations, tin concentration operations and tin scavenging operations, to obtain flotation 2 tin concentrate;

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

[0015] Aiming at the problems of low feed tin grade, large difference in tin grade of each particle size, low tin recovery rate, high tin flotation cost and high tin recovery cost in the process of cassiterite recovery in shaking table tailings, which lead to the difficulty that this part of tin resources cannot be efficiently recycled and utilized, the present invention obtains tin-containing products with different particle sizes and properties through screening and grading of shaking table tailings and cyclone grading, adopts adaptation processes for tin products of different particle sizes in a targeted manner, and realizes tin pre-enrichment through "tin flotation-shaking table gravity separation" and "reverse flotation-tin flotation-centrifugal gravity separation" processes respectively. Specifically, the present invention can pre-remove the coarse particle product with low tin grade and extremely poor flotation recovery effect in the shaking table tailings through screening and classification; obtain the fine particle product with high tin grade under the screen and enter the cyclone for further classification to obtain the coarse particle sediment of the cyclone and the fine particle overflow of the cyclone; carry out tin flotation operation on the coarse particle sediment of the cyclone which is easy to float and has less ore mud content, and obtain the flotation 1 tin concentrate with a tin grade of about 10% through tin flotation; use the shaking table to re-select the flotation 1 tin concentrate to obtain the tin grade of about 10%; The tin content of the tin concentrate was increased to more than 30% to obtain a high-grade shaking table tin concentrate; the cyclone fine particles that were difficult to float and had a high slime content were subjected to reverse flotation and tin flotation to obtain a higher-grade flotation 2 tin concentrate; the tin grade of the flotation 2 tin concentrate was increased to more than 20% by centrifugal gravity separation to obtain a high-grade centrifugal tin concentrate; finally, products of different properties and particle size properties were obtained through grading, classification and quality separation, and combined with suitable processes, the low-cost and efficient recovery of cassiterite in the shaking table tailings was achieved.

[0016] The present invention transforms wide-grade tin tailings into narrow-grade tin tailings by coordinating a plurality of grading processes, and then cooperates with the process most suitable for the particle size, and according to the principle of first ensuring the recovery rate and then improving the quality, realizes the efficient recovery of low-grade tin in the shaking table tailings by the method of classification, grading and quality separation, and finally obtains a high-grade and high-recovery tin concentrate product, not only obtains high-grade tin concentrate, but also significantly reduces the tin flotation cost, provides a practical method for the beneficiation plant to develop and utilize such tin resources, not only avoids the waste of resources, but also significantly improves the efficiency of the beneficiation plant.

[0017] Furthermore, in step S1, the screening particle size 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 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 iron sulfate in a mass ratio of 3-5:1. The present invention preferably uses the above-mentioned flotation reagent A, which has a good collection ability for tin minerals and is not easy to fall off during coarse particle flotation, so that the tin minerals can be separated more easily, 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 tin flotation roughing operation, tin concentration 1 operation, tin concentration 2 operation, tin concentration 3 operation and tin scavenging operation; during the tin flotation roughing operation, a flotation agent A in an amount of 800-1200 g / t is added; during the tin concentration 2 operation, a flotation agent B in an amount of 400-800 g / t is added, and during the tin scavenging operation, a flotation agent A in an amount of 200-300 g / t is added.

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

[0024] Furthermore, 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).

[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 the flotation reagent E) to react with Sn 4+ The coordination to form a stable complex and the -NH- group's electrostatic adsorption to tin ore, but weak adsorption to ore mud, ensures efficient tin enrichment and recovery at low dosage.

[0027] Furthermore, the tin flotation operation in step S6 includes tin flotation roughing operation, tin concentration 1 operation, tin concentration 2 operation, tin concentration 3 operation and 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; 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 re-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, in step S7, the feed concentration 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 for tin products of different particle sizes in a targeted manner. Tin pre-enrichment is achieved through the "tin flotation-shaking table gravity separation" and "reverse flotation-tin flotation-centrifugal gravity separation" processes, respectively, so as to achieve low-cost and high-efficiency recovery of cassiterite in the shaking table tailings, and finally obtain a high-grade, high-recovery tin concentrate product. Not only a high-grade tin concentrate is obtained, but also the tin flotation cost is significantly reduced, providing a practical method for the concentrator to develop and utilize such tin resources, which not only avoids the waste of resources, but also significantly improves the efficiency of the concentrator.

[0034] (2) The screening and pre-tailing of the present invention significantly reduces the amount of tin flotation, and the screening and grading greatly reduces the flotation equipment and flotation costs, while preventing the tin flotation sedimentation tank problem; 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 the low-mud material for flotation, and an anti-mud interference collector (flotation agent B) is used for the high-mud material. By using 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 further adopts different gravity separation processes to improve the flotation grade of the moderate-grade flotation concentrate obtained by different flotation processes, 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 combined flotation-gravity 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 the gravity separation is to improve the grade. By utilizing the characteristics of high enrichment ratio and low recovery rate of the shaking table gravity separation, the low-grade shaking table middlings are returned to the tin flotation to avoid the loss of recovery rate. By utilizing the characteristics of low enrichment ratio but high recovery rate of centrifugal gravity separation, an open-circuit centrifugal gravity separation process is adopted (i.e., 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), thereby further removing low-grade high-mud materials, realizing 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 It 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 content percentages in each example are all mass percentages.

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

[0042] The test sample is a shaking table gravity separation tailings of a high-silver tin polymetallic mine in Inner Mongolia, in which the tin grade is 0.38%, and 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 method for recovering cassiterite from the shaking table 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 graded by a hydrocyclone according to the 0.038mm particle size to obtain the coarse-grained sand settling of the hydrocyclone and the fine-grained overflow of the hydrocyclone;

[0047] S3 Tin Flotation 1 Operation

[0048] Add 800 g / t of flotation reagent A to the obtained coarse sediment of the cyclone, stir for 10 minutes and enter the tin flotation roughing operation to obtain tin roughing concentrate and tin roughing tailings; the tin roughing concentrate enters the tin concentrating 1 operation to obtain tin concentrating 1 concentrate and concentrating 1 tailings; add 400 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 concentrating 3 tailings; add 200 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 the 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 Shaker Gravity Selection Operation

[0050] The flotation 1 tin concentrate obtained in step S3 is sent to a shaking table for re-selection. 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 a shaking table tin concentrate and a shaking table tin medium ore. The shaking table tin medium ore is returned to the tin flotation roughing operation of step S3.

[0051] S5 reverse flotation operation

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

[0053] S6 Tin Flotation 2 Operation

[0054] Add 1000 g / t of flotation reagent D and 600 g / t of flotation reagent E to the reverse flotation tailings obtained in step S5, stir for 30 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 400 g / t of flotation reagent D 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 2 tin concentrate and concentrating 3 tailings; add 150 g / t of flotation reagent E to the tin roughing tailings and enter the tin scavenging operation to obtain tin scavenging concentrate and tin scavenging tailings; the concentrating 1 tailings and the 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;

[0055] S7 Centrifugal Gravity Separation Operation

[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 45S and a single washing time of 5S, to obtain a centrifugal rough concentrate and a roughing tailing; the centrifugal rough concentrate is subjected to a centrifugal concentration 1 operation, with a centrifugal acceleration of 45G, to obtain a centrifugal concentration 1 concentrate and a centrifugal concentration 1 tailing; the centrifugal concentration 1 concentrate enters a centrifugal concentration 2 operation, with a centrifugal acceleration of 35G, to obtain a centrifugal tin concentrate and a centrifugal concentration 2 tailing; the roughing tailing, the centrifugal concentration 1 tailing, and the centrifugal concentration 2 tailing are combined into a centrifugal tailing. The centrifugal tailing and the tin scavenging tailing obtained in step S6 are combined into tin tailing 2. The centrifugal tin concentrate and the shaking table tin concentrate obtained in step S4 are combined into the final tin concentrate.

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

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

[0059] The test sample is a tin-polymetallic ore tailings from a shaking table in Gejiu, Yunnan, in which the tin grade is 0.56%, and silicate minerals such as feldspar, quartz, and chlorite are the main gangue minerals, of which the content of -0.15 mm particle size is 68%. The 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] -0.1mm sieve-less fine products are graded by cyclone according to the 0.038mm particle size to obtain cyclone coarse sand settling and cyclone fine overflow;

[0064] S3 Tin Flotation 1 Operation

[0065] Add 1200 g / t of flotation reagent A to the obtained coarse sediment of the cyclone, stir for 15 minutes and enter the tin flotation roughing operation to obtain tin roughing concentrate and tin roughing tailings; the tin roughing concentrate enters the tin concentrating 1 operation to obtain tin concentrating 1 concentrate and concentrating 1 tailings; add 800 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 concentrating 3 tailings; add 300 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 the 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 Shaker Gravity Selection Operation

[0067] The flotation 1 tin concentrate obtained in step S3 is sent to 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 a shaking table tin concentrate and a shaking table tin medium ore. The shaking table tin medium ore is returned to the tin flotation roughing operation of step S3.

[0068] S5 reverse flotation operation

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

[0070] S6 Tin Flotation 2 Operation

[0071] Add 1500 g / t of flotation reagent D and 800 g / t of flotation reagent E to the reverse flotation tailings obtained in step S5, stir for 45 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 1 operation to obtain tin concentrating 1 concentrate and concentrating 1 tailings; add 800 g / t of flotation reagent D to the obtained tin concentrating 1 concentrate, and then 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 2 tin concentrate and concentrating 3 tailings; add 200 g / t of flotation reagent E to the tin roughing tailings, and then enter the tin scavenging operation to obtain tin scavenging concentrate and tin scavenging tailings; the concentrating 1 tailings and the 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;

[0072] S7 Centrifugal Gravity Separation Operation

[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, and a centrifugal roughing operation is performed, with a single feeding time of 55S and a single washing time of 10S, to obtain a centrifugal rough concentrate and a roughing tailing; the centrifugal rough concentrate is subjected to a centrifugal concentration 1 operation, with a centrifugal acceleration of 55G, to obtain a centrifugal concentration 1 concentrate and a centrifugal concentration 1 tailing; the centrifugal concentration 1 concentrate enters a centrifugal concentration 2 operation, with a centrifugal acceleration of 45G, to obtain a centrifugal tin concentrate and a centrifugal concentration 2 tailing; the roughing tailing, the centrifugal concentration 1 tailing, and the centrifugal concentration 2 tailing are combined into a centrifugal tailing. The centrifugal tailing and the tin scavenging tailing obtained in step S6 are combined into tin tailing 2. The centrifugal tin concentrate and the shaking table tin concentrate obtained in step S4 are combined into the final tin concentrate.

[0074] Finally, we obtained shaking table tin concentrate with tin grade of 36.85% and recovery rate of 61.20% and centrifugal tin concentrate with tin grade of 23.54% and recovery rate of 20.93%, and the comprehensive tin grade of 32.21% and total tin recovery rate of 82.13%.

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

[0076] The test sample is a shaking table gravity separation tailings of a copper-tin polymetallic mine in Ximeng, Inner Mongolia, in which the tin grade is 0.29%, and silicate minerals such as feldspar, tourmaline, chlorite, and mica are the main gangue minerals, of which the content of -0.15 mm particle size is 63%. The ore dressing method for recovering cassiterite from shaking table 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 graded by a cyclone according to the 0.043mm particle size to obtain the cyclone coarse-grained sand settling and the cyclone fine-grained overflow;

[0081] S3 Tin Flotation 1 Operation

[0082] Add 1000 g / t of flotation reagent A to the obtained coarse sediment of the cyclone, stir for 15 minutes and enter the tin flotation roughing operation to obtain tin roughing concentrate and tin roughing tailings; the tin roughing concentrate enters the tin concentrating 1 operation 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 the 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 Shaker Gravity Selection Operation

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

[0085] S5 reverse flotation operation

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

[0087] S6 Tin Flotation 2 Operation

[0088] Add 1500 g / t of flotation reagent D and 800 g / t of flotation reagent E to the reverse flotation tailings obtained in step S5, stir for 45 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 600 g / t of flotation reagent D 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 2 tin concentrate and concentrating 3 tailings; add 200 g / t of flotation reagent E to the tin roughing tailings and enter the tin scavenging operation to obtain tin scavenging concentrate and tin scavenging tailings; the concentrating 1 tailings and the 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;

[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, and a centrifugal roughing operation is performed, with a single feeding time of 55S and a single washing time of 10S, to obtain a centrifugal rough concentrate and a roughing tailing; the centrifugal rough concentrate is subjected to a centrifugal concentration 1 operation, with a centrifugal acceleration of 55G, to obtain a centrifugal concentration 1 concentrate and a centrifugal concentration 1 tailing; the centrifugal concentration 1 concentrate enters a centrifugal concentration 2 operation, with a centrifugal acceleration of 45G, to obtain a centrifugal tin concentrate and a centrifugal concentration 2 tailing; the roughing tailing, the centrifugal concentration 1 tailing, and the centrifugal concentration 2 tailing are combined into a centrifugal tailing. The centrifugal tailing and the tin scavenging tailing obtained in step S6 are combined into tin tailing 2. The centrifugal tin concentrate and the shaking table tin concentrate obtained in step S4 are combined into 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 -0.074 mm particle size content 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 hydrocyclone to remove mud and obtain hydrocyclone 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] Add 800 g / t of flotation reagent A to the obtained cyclone sediment, stir for 10 minutes and enter the tin flotation roughing operation to obtain tin roughing concentrate and tin roughing tailings; the tin roughing concentrate enters the tin concentrating 1 operation to obtain tin concentrating 1 concentrate and concentrating 1 tailings; add 400 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 tin concentrate and concentrating 3 tailings; add 200 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; the concentrating 1 tailings and the 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 shaker gravity separation

[0100] The flotation tin concentrate obtained in step S2 is sent to 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 a shaking table tin concentrate and a shaking table tin middlings;

[0101] Finally, the "desludging-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 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 -0.074 mm particle size content is 58%.

[0104] The ore dressing 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, we obtained shaking table tin concentrate with tin grade of 33.54% and recovery rate of 45.01% and centrifugal tin concentrate with tin grade of 16.75% and recovery rate of 21.67%, and the comprehensive tin grade of 25.29% and total tin recovery rate of 66.68%.

[0107] Comparative Example 3: A 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 -0.074 mm particle size content is 58%.

[0109] The ore dressing 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 the tin flotation 1 operation is replaced with the same type of reagent as that used in the tin flotation 2 operation, as shown in Table 1. Finally, a shaking table tin concentrate with a tin grade of 32.75% and a recovery rate of 34.92% and a centrifugal tin concentrate with a tin grade of 21.86% and a recovery rate of 29.43% are obtained, and a tin concentrate with a comprehensive tin grade of 26.67% and a total tin recovery rate of 64.35% is obtained.

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

[0112] Table 1 Types and proportions of medicines in the examples and comparative examples

[0113]

[0114]

[0115] Comparative Example 1 uses a conventional tin flotation process, i.e., "de-sludge-tin flotation-tin gravity separation process" to recover tin from the shaking table tailings, and finally obtains a tin concentrate with a tin grade of 26.58% and a recovery rate of 40.03%. In Example 1, the ore dressing method of the patent of the present invention, i.e., the process of "removal-classification-coarse particle flotation + shaking table-fine particle reverse flotation + flotation + centrifugation", is adopted, and the tin recovery rate of Example 1 is increased by 34.41 percentage points. The new process significantly improves the tin grade and recovery rate of the concentrate, while reducing the concentrate yield, flotation processing volume and reagent dosage. The ability of on-site tin flotation to respond to market and resource changes is enhanced, providing a guarantee for 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 of tin flotation 1, compared with Example 1, the tin grade of tin recovered from the cyclone overflow, i.e., centrifugal tin concentrate, was reduced from 21.86% to 16.75%, and the tin recovery rate was reduced from 29.43% to 21.67%, indicating that after replacing reagent E with reagent A and reagent D with reagent B, the tin index of the fine particle part was significantly deteriorated. Although the same tin flotation was performed, reagents E and D had 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 sedimentation, i.e., the shaking table tin concentrate, was reduced from 33.54% to 32.75%, and the tin recovery rate was reduced from 45.01% to 34.92%, indicating that after reagent A was replaced by reagent E and reagent B was replaced by reagent D, the tin index of the coarse particle part was significantly deteriorated. Although it is the same tin flotation, reagents A and B have better capture ability for low-mud coarse tin.

Claims

1. A method for recovering cassiterite from shaking table tailings, characterized in that: The following steps are involved: S1: Screening the shaking table tailings to obtain coarse particles on the screen and fine particles under the screen; S2: The fine particles under the screen are classified by a hydrocyclone to obtain the coarse sedimentation of the hydrocyclone and the fine overflow of the hydrocyclone; S3: adding flotation reagents to the coarse sediment in the hydrocyclone to carry out tin flotation operation, the tin flotation operation includes tin flotation roughing operation, tin concentrating operation and tin scavenging operation, and obtaining flotation 1 tin concentrate; S4: sending the flotation 1 tin concentrate to the shaking table re-selection operation to obtain shaking table tin concentrate and shaking table tin middlings; S5: adding flotation reagent 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 operations, wherein the tin flotation operations include tin flotation roughing operations, tin concentration operations and tin scavenging operations, to obtain flotation 2 tin concentrate; S7: The flotation 2 tin concentrate is subjected to centrifugal re-selection 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 iron 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 tin flotation roughing operation, tin concentration 1 operation, tin concentration 2 operation, tin concentration 3 operation and tin scavenging operation; during the tin flotation roughing operation, a flotation agent A in an amount of 800-1200 g / t is added; during the tin concentration 2 operation, a flotation agent B in an amount of 400-800 g / t is added, and during the tin scavenging operation, a flotation agent 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 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 method for recovering cassiterite from shaking table tailings according to claim 8, characterized in that: The tin flotation operation in step S6 includes tin flotation roughing operation, tin concentration 1 operation, tin concentration 2 operation, tin concentration 3 operation and 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; 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 re-selection 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.

Images