Mineral processing technology for recovering tin from iron-tin ore reselection tailings

Abstract

The invention discloses a mineral separation process for recovering tin from iron-tin ore gravity separation tailings. The beneficiation process comprises the following steps that S1, iron-tin ore gravity separation tailings are graded, and coarse-grain products and fine-grain products are obtained; s2, the coarse grain products are graded, and three products with the grain fractions of + 0.3 mm,-0.3 + 0.074 mm and-0.074 mm are obtained; s3, the product with the particle size of + 0.3 mm is subjected to ore grinding, and an ore grinding product is obtained; s4, combining and concentrating the fine particle product and the-0.074 mm product to obtain overflow water and settled sand; s5, the ore grinding product and the settled sand are subjected to low-intensity magnetic separation, and iron ore concentrate and iron tailings are obtained; s6, the sulfur tailings are subjected to desulfurization and dearsenification flotation, and sulfur-arsenic concentrate and sulfur-arsenic tailings are obtained; s7, the sulfur and arsenic tailings are subjected to tin flotation, and tin flotation concentrate and tin flotation tailings are obtained; and S8, the tin flotation concentrate is subjected to reverse flotation impurity removal, and tin concentrate and arsenic concentrate are obtained. According to the process, the iron-tin ore tailings are treated, quality improvement and impurity reduction of the tin concentrate are achieved, and the quality of the tin concentrate is improved to 20%-30%.

Description

Technical Field:

[0001] The present invention relates to the technical field of mineral processing, and particularly relates to a beneficiation process for recovering tin from the gravity separation tailings of iron-tin ore. Background Art:

[0002] In recent years, with the rapid development of the national economy, the utilization of metal raw ore resources has increased year by year. To alleviate the shortage of resources, the research and development of tailings resources have attracted more and more attention from the country. Iron-tin ore is a typical symbiotic deposit of iron and tin. Representative deposits include Dading in Guangdong and Huanggang in Inner Mongolia. Among them, tin is closely symbiotic with magnetite and iron-bearing gangue. The dissemination size of tin is very fine, and most of it exists in the form of colloidal tin, making comprehensive utilization difficult. There is also a small amount of tungsten resources associated. Most concentrators only use gravity separation processes to recover some coarsely liberated cassiterite, resulting in the loss of finely disseminated cassiterite in the tailings and causing waste of resources. Implementing a reasonable process to efficiently recover tin and tungsten resources from the gravity separation tailings of iron-tin ore is crucial for improving the resource utilization level in China. Summary of the Invention:

[0003] The present invention solves the problems existing in the prior art and provides a beneficiation process for recovering tin from the gravity separation tailings of iron-tin ore. The process proposed by the present invention can treat iron-tin ore tailings containing Sn 0.3% - 0.5% (40% - 80% of Sn exists as cassiterite), WO 3 0.05% - 0.15%, TFe 15% - 20%, mFe 0.1% - 0.8%, S 0.3% - 0.8%, As 0.5% - 1.5% to obtain products such as tin concentrate, iron concentrate, sulfur-arsenic concentrate, and arsenic concentrate. Among them, the tin concentrate contains Sn 10% - 30%, WO 3 5% - 10%, the Sn recovery rate is 40% - 60%, WO 3 The recovery rate is 50% - 70%, realizing the comprehensive utilization of tailings resources.

[0004] The purpose of the present invention is to provide a beneficiation process for recovering tin from the gravity separation tailings of iron-tin ore, including the following steps:

[0005] S1. Hydrocyclone Classification: Classify the gravity separation tailings of iron-tin ore using a hydrocyclone to obtain coarse-grained products and fine-grained products. The diameter of the hydrocyclone underflow nozzle φ is 50 - 100 mm, the pressure is 0.1 - 0.3 Mpa, and the classification efficiency for 0.074 mm is 40% - 60%;

[0006] S2. Classification: Classify the coarse-grained products obtained in step S1 to obtain three products with particle sizes of +0.3 mm, -0.3 + 0.074 mm, and -0.074 mm;

[0007] S3. Grinding: Grind the +0.3 mm particle size product obtained in step S2 to obtain a ground product;

[0008] S4, Concentration: Combine and concentrate the fine-grained product in step S1 and the -0.074mm product in step S2 to obtain overflow water and sand deposits;

[0009] S5, Low-intensity magnetic separation: Conduct low-intensity magnetic separation on the ground product in step S3 and the sand deposits in step S4 to obtain iron concentrate and iron tailings;

[0010] S6, Desulfurization and dearsenification flotation: Conduct desulfurization and dearsenification flotation on the sulfur tailings in step S5 to obtain sulfur-arsenic concentrate and sulfur-arsenic tailings;

[0011] S7, Tin flotation: Conduct tin flotation on the sulfur-arsenic tailings in step S6 to obtain tin flotation concentrate and tin flotation tailings;

[0012] S8, Reverse flotation for impurity removal: Conduct reverse flotation for impurity removal on the tin flotation concentrate in step S7 to obtain tin concentrate and arsenic concentrate.

[0013] Preferably, the gravity separation tailings of iron-tin ore in step S1 are the tailings after magnetic separation of iron, flotation of zinc, and gravity separation of tin from iron-tin ore, containing 0.3% - 0.5% Sn, WO 3 0.05% - 0.15%, TFe 15% - 20%, mFe 0.1% - 0.8%, S 0.3% - 0.8%, As 0.5% - 1.5%. 40 - 80% of the Sn in iron-tin ore exists as cassiterite, and the rest exists as colloidal tin or isomorphic substitution in garnet.

[0014] Preferably, the diameter of the cyclone sand discharge nozzle φ is 50 - 100mm, the pressure is 0.15 - 0.25Mpa, and the classification efficiency of -0.074mm is 52% - 55%.

[0015] Preferably, the coarse-grained product in step S2 is classified by a high-frequency screen. The high-frequency screen is double-layered. Among them, the Sn content in the -0.074mm particle size fraction > the +0.3mm particle size fraction > the -0.3 + 0.074mm particle size fraction. The -0.3 + 0.074mm particle size fraction is directly discarded as waste, and its yield is 20% - 35%.

[0016] Preferably, the grinding fineness of the ground product in step S3 is that -0.074mm accounts for 60% - 80%. The grinding equipment is an Isa mill or a vertical agitator mill.

[0017] Preferably, the concentration of the sand deposits in step S4 is 25% - 40%, and the solid content of the overflow water < 0.5%.

[0018] Preferably, the magnetic field intensity of the low-intensity magnetic separation in step S5 is 1500 - 3000GS. Further preferably, the magnetic field intensity of the low-intensity magnetic separation in step S5 is 2000 - 3000GS.

[0019] Preferably, the desulfurization and dearsenification flotation described in step S6 adopts a closed-circuit flotation process of one roughing, one scavenging, and one cleaning. The reagents added in the roughing include 50 - 100 g / t of copper sulfate, 100 - 200 g / t of amyl xanthate, and 30 - 50 g / t of a monohydric alcohol. The reagent added in the scavenging is 50 - 100 g / t of amyl xanthate, and no reagent is added in the cleaning. The monohydric alcohol is a miscellaneous alcohol with the chemical formula R-OH, where R is selected from hydrocarbon groups with 6 - 10 carbon atoms.

[0020] More preferably, the desulfurization and dearsenification flotation described in step S6 adopts a closed-circuit flotation process of one roughing, one scavenging, and one cleaning. The reagents added in the roughing include 80 - 100 g / t of copper sulfate, 120 - 200 g / t of amyl xanthate, and 30 - 50 g / t of a monohydric alcohol. The reagent added in the scavenging is 60 - 80 g / t of amyl xanthate, and no reagent is added in the cleaning.

[0021] Preferably, the tin flotation described in step S7 adopts a closed-circuit flotation process of one roughing, two scavengings, and three cleanings. The reagents added in the roughing include 300 - 600 g / t of lead nitrate, 500 - 1000 g / t of benzohydroxamic acid (GYB), 50 - 100 g / t of diesel oil, and 50 - 100 g / t of tributyl phosphate (TBP). The reagents added in the first scavenging include 200 - 400 g / t of GYB, 30 - 60 g / t of diesel oil, and 30 - 60 g / t of TBP. The reagents added in the second scavenging include 100 - 200 g / t of GYB, 20 - 40 g / t of diesel oil, and 20 - 40 g / t of TBP. The reagent added in the first cleaning is 200 - 300 g / t of water glass, the reagent added in the second cleaning is 100 - 200 g / t of water glass, and the reagent added in the third cleaning is 50 - 100 g / t of water glass.

[0022] More preferably, the reagents added in the roughing include 400 - 600 g / t of lead nitrate, 600 - 1000 g / t of benzohydroxamic acid (GYB), 50 - 100 g / t of diesel oil, and 50 - 100 g / t of tributyl phosphate (TBP). The reagents added in the first scavenging include 300 - 400 g / t of GYB, 30 - 60 g / t of diesel oil, and 30 - 60 g / t of TBP. The reagents added in the second scavenging include 150 - 200 g / t of GYB, 20 - 40 g / t of diesel oil, and 20 - 40 g / t of TBP.

[0023] Preferably, the reverse flotation for impurity removal described in step S8 adopts an open-circuit flotation process of one roughing, two cleanings, and tailings merging. The reagents added in the roughing include 1000 - 2000 g / t of sulfuric acid and 10 - 20 g / t of a monohydric alcohol, and no reagent is added in the cleaning.

[0024] More preferably, the reagents added in the roughing include 1000 - 2000 g / t of sulfuric acid and 10 - 15 g / t of a monohydric alcohol, and no reagent is added in the cleaning.

[0025] Preferably, in steps S5-S8, tin concentrate, iron concentrate, sulfur-arsenic concentrate, and arsenic concentrate are obtained. The tin concentrate contains 10%-30% Sn and 5%-10% WO 3 5%-10%, the Sn recovery rate is 40%-60%, and the WO 3 recovery rate is 50%-70%. The iron concentrate is mainly magnetite, the sulfur-arsenic concentrate is mainly pyrite and arsenopyrite, and the arsenic concentrate is mainly loellingite.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] 1. The present invention realizes the pre-rejection of waste from iron-tin ore tailings. The amount of iron-tin ore tailings is large, and the overall treatment cost is high. Rejecting the relatively better intermediate particle size can effectively reduce the feed volume and improve the operation efficiency.

[0028] 2. The present invention realizes the upgrading and impurity reduction of tin concentrate. There are many interference factors in tin flotation, including iron-containing minerals, sulfide minerals, clay minerals, etc. The Sn grade of conventional process tin concentrate is 2%-5%. Through reasonable magnetic separation, desulfurization and dearsenification, inhibition of tin beneficiation with modified water glass, reverse flotation for impurity removal and other processes, the interference of various gangues is effectively reduced, and the quality of tin concentrate is improved to 20%-30%.

[0029] 3. The present invention realizes the efficient comprehensive recovery of tin and tungsten resources. Through the combination of reagents such as GYB, diesel, and TBP, the selective flotation of tin and tungsten and the efficient flotation of fine-grained tin and tungsten are realized.

[0030] 4. The present invention realizes the harmless discharge of tailings. The ore contains a large amount of As, and the leaching toxicity of As exceeds the standard. While recovering tin and tungsten, the present invention realizes the separation and extraction of two main arsenic minerals, arsenopyrite and loellingite, effectively reducing the As content in the tailings and making its leaching toxicity meet the standard. Description of the drawings:

[0031] Figure 1 is a flow chart of the beneficiation process for recovering tin from the gravity separation tailings of iron-tin ore in the present invention. Detailed implementation manners:

[0032] The following examples are further descriptions of the present invention, rather than limitations on the present invention.

[0033] Unless otherwise defined, all technical terms used hereinafter have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention. Unless otherwise specified, the experimental materials and reagents in this article are all commercially available products commonly used in this technical field. The monohydric alcohol is a fusel alcohol, with the chemical formula R-OH, where R is selected from hydrocarbon groups with 6 to 10 carbon atoms. Preferably in the following embodiments, the monohydric alcohol is 1-heptanol and / or 1-octanol.

[0034] Example 1

[0035] Refer to Figure 1 , a beneficiation process for recovering tin from the gravity separation tailings of iron-tin ore, specifically including the following steps:

[0036] S1. Cyclone classification: The gravity separation tailings of iron-tin ore are classified by a cyclone. The cyclone underflow nozzle φ is 50 mm, the pressure is 0.15 Mpa, and the classification efficiency of 0.074 mm is 55%. Coarse-grained products and fine-grained products are obtained.

[0037] S2. High-frequency screen classification: The coarse-grained products in step S1 are classified by a high-frequency screen to obtain three products with particle sizes of +0.3 mm, -0.3 + 0.074 mm, and -0.074 mm. The high-frequency screen is double-layered, where the Sn content in the -0.074 mm particle size grade > +0.3 mm particle size grade > -0.3 + 0.074 mm particle size grade. The -0.3 + 0.074 mm particle size grade is directly discarded, and its yield is 25%.

[0038] S3. Grinding: The +0.3 mm particle size products in step S2 are ground, and the grinding fineness is 69% passing through -0.074 mm to obtain ground products.

[0039] S4. Concentration: The fine-grained products in step S1 and the -0.074 mm products in step S2 are combined and fed into a thickener or a concentrator for sedimentation and concentration to obtain overflow water and underflow. The concentration of the concentrated underflow is 27%, and the solid content of the overflow water is 0.22%.

[0040] S5. Low-intensity magnetic separation: The ground products in step S3 and the underflow in step S4 are subjected to low-intensity magnetic separation with a magnetic field intensity of 3000 GS to obtain iron concentrate and iron tailings.

[0041] S6. Desulfurization and dearsenification flotation: The sulfur tailings in step S5 are subjected to desulfurization and dearsenification flotation, adopting a closed-circuit flotation process of 1 roughing, 1 scavenging, and 1 cleaning. The reagents used in roughing include 80 g / t of copper sulfate, 150 g / t of amyl xanthate, and 50 g / t of monohydric alcohol. 75 g / t of amyl xanthate is used in scavenging, and no reagents are added in cleaning to obtain sulfur-arsenic concentrate and sulfur-arsenic tailings.

[0042] S7. Tin flotation: The sulfur-arsenic tailings from step S6 are subjected to tin flotation, adopting a closed-circuit flotation process of 1 roughing, 2 scavengings, and 3 cleanings. The reagents used in roughing include 400 g / t of lead nitrate, 800 g / t of benzohydroxamic acid (GYB), 70 g / t of C6-8 diesel, and 70 g / t of tributyl phosphate (TBP). The reagents used in scavenging 1 include 400 g / t of GYB, 40 g / t of diesel, and 40 g / t of TBP. The reagents used in scavenging 2 include 200 g / t of GYB, 20 g / t of diesel, and 20 g / t of TBP. The reagent used in cleaning 1 is 300 g / t of modified water glass, the reagent used in cleaning 2 is 200 g / t of modified water glass, and the reagent used in cleaning 3 is 100 g / t of modified water glass, obtaining tin flotation concentrate and tin flotation tailings;

[0043] S8. Reverse flotation for impurity removal: The tin flotation concentrate from step S7 is subjected to reverse flotation for impurity removal, adopting an open-circuit flotation process of 1 roughing and 2 cleanings with the tailings combined. The reagents used in roughing include 2000 g / t of sulfuric acid and 10 g / t of monohydric alcohol. No reagents are added in cleaning, obtaining tin concentrate and arsenic concentrate.

[0044] Using the above process for treatment, for the feed ore containing 0.43% Sn and 3 0.11% WO 3 tin concentrate containing 23.25% Sn and

[0045] Example 2

[0046] Refer to Figure 1 , a beneficiation process for recovering tin from the gravity separation tailings of iron-tin ore, specifically including the following steps:

[0047] S1. Hydrocyclone classification: The gravity separation tailings of iron-tin ore are classified by a hydrocyclone. The diameter of the hydrocyclone underflow nozzle φ is 75 mm, the pressure is 0.22 Mpa, and the classification efficiency of 0.074 mm is 53%, obtaining coarse-grained products and fine-grained products;

[0048] S2. High-frequency screen classification: The coarse-grained products from step S1 are classified by a high-frequency screen, obtaining three kinds of products with particle sizes of +0.3 mm, -0.3 + 0.074 mm, and -0.074 mm. The high-frequency screen is double-layered. Among them, the Sn content in the -0.074 mm particle size grade > +0.3 mm particle size grade > -0.3 + 0.074 mm particle size grade. The -0.3 + 0.074 mm particle size grade is directly discarded as waste, and its yield is 27%;

[0049] S3. Grinding: The +0.3 mm particle size grade products from step S2 are ground, and the grinding fineness is 63% passing -0.074 mm, obtaining ground products;

[0050] S4. Concentration: Combine the fine-grained products in step S1 and the -0.074 mm products in step S2 and feed them into a thickener or a thickening tank for sedimentation and concentration to obtain overflow water and sand sediment. The concentration of the concentrated sand sediment is 35%, and the solid content of the overflow water is 0.35%.

[0051] S5. Low-intensity magnetic separation: Conduct low-intensity magnetic separation on the grinding products in step S3 and the sand sediment in step S4 at a magnetic field intensity of 2000 GS to obtain iron concentrate and iron tailings.

[0052] S6. Desulfurization and dearsenification flotation: Conduct desulfurization and dearsenification flotation on the sulfur tailings in step S5 using a closed-circuit flotation process of one roughing, one scavenging, and one cleaning. The reagents used in roughing include 100 g / t of copper sulfate, 120 g / t of amyl xanthate, and 30 g / t of monohydric alcohol. The reagent used in scavenging is 60 g / t of amyl xanthate, and no reagent is added in cleaning to obtain sulfur-arsenic concentrate and sulfur-arsenic tailings.

[0053] S7. Tin flotation: Conduct tin flotation on the sulfur-arsenic tailings in step S6 using a closed-circuit flotation process of one roughing, two scavengings, and three cleanings. The reagents used in roughing include 400 g / t of lead nitrate, 600 g / t of benzohydroxamic acid (GYB), 50 g / t of C6-8 diesel, and 50 g / t of tributyl phosphate (TBP). The reagents used in the first scavenging include 300 g / t of GYB, 30 g / t of diesel, and 30 g / t of TBP. The reagents used in the second scavenging include 150 g / t of GYB, 20 g / t of diesel, and 20 g / t of TBP. The reagent used in the first cleaning is 200 g / t of modified water glass, the reagent used in the second cleaning is 100 g / t of modified water glass, and the reagent used in the third cleaning is 50 g / t of modified water glass to obtain tin flotation concentrate and tin flotation tailings.

[0054] S8. Reverse flotation for impurity removal: Conduct reverse flotation for impurity removal on the tin flotation concentrate in step S7 using an open-circuit flotation process of one roughing, two cleanings, and combining the tailings. The reagents used in roughing include 1000 g / t of sulfuric acid and 10 g / t of monohydric alcohol, and no reagent is added in cleaning to obtain tin concentrate and arsenic concentrate.

[0055] Using the above process for treatment, for the feed ore containing 0.38% Sn and 3 0.087% WO 3 a tin concentrate containing 20.35% Sn and 5.74% WO is obtained, and the recovery rates of tin and tungsten are 45.26% and 58.71% respectively.

[0056] Example 3

[0057] Refer to Figure 1 , a beneficiation process for recovering tin from the gravity separation tailings of iron-tin ore, specifically including the following steps:

[0058] S1. Cyclone classification: The gravity separation tailings of iron-tin ore are classified by a cyclone. The diameter of the cyclone underflow nozzle φ is 100 mm, the pressure is 0.25 Mpa, and the classification efficiency of 0.074 mm is 52%. Coarse-grained products and fine-grained products are obtained.

[0059] S2. High-frequency screen classification: The coarse-grained products from step S1 are classified by a high-frequency screen to obtain three products with particle sizes of +0.3 mm, -0.3 + 0.074 mm, and -0.074 mm. The high-frequency screen is double-layered. Among them, the Sn content in the -0.074 mm particle size > +0.3 mm particle size > -0.3 + 0.074 mm particle size. The -0.3 + 0.074 mm particle size is directly discarded as waste, and its yield is 22%.

[0060] S3. Grinding: The +0.3 mm particle size products from step S2 are ground, and the grinding fineness is 75% passing through 0.074 mm to obtain ground products.

[0061] S4. Thickening: The fine-grained products from step S1 and the -0.074 mm products from step S2 are combined and fed into a thickener or a thickening tank for sedimentation and thickening to obtain overflow water and underflow. The concentration of the thickened underflow is 30%, and the solid content of the overflow water is 0.29%.

[0062] S5. Low-intensity magnetic separation: The ground products from step S3 and the underflow from step S4 are subjected to low-intensity magnetic separation with a magnetic field intensity of 2000 GS to obtain iron concentrate and iron tailings.

[0063] S6. Desulfurization and dearsenification flotation: The sulfur-containing tailings from step S5 are subjected to desulfurization and dearsenification flotation. A closed-circuit flotation process of 1 roughing, 1 scavenging, and 1 cleaning is adopted. The reagents used in roughing include 100 g / t of copper sulfate, 200 g / t of amyl xanthate, and 40 g / t of monohydric alcohol. The reagent used in scavenging is 80 g / t of amyl xanthate. No reagent is added in cleaning to obtain sulfur-arsenic concentrate and sulfur-arsenic tailings.

[0064] S7. Tin flotation: The sulfur-arsenic tailings from step S6 are subjected to tin flotation. A closed-circuit flotation process of 1 roughing, 2 scavenging, and 3 cleaning is adopted. The reagents used in roughing include 600 g / t of lead nitrate, 1000 g / t of benzohydroxamic acid (GYB), 100 g / t of C6 - 8 diesel, and 100 g / t of tributyl phosphate (TBP). The reagents used in the first scavenging include 400 g / t of GYB, 60 g / t of diesel, and 60 g / t of TBP. The reagents used in the second scavenging include 200 g / t of GYB, 40 g / t of diesel, and 40 g / t of TBP. The reagent used in the first cleaning is 300 g / t of modified water glass. The reagent used in the second cleaning is 200 g / t of modified water glass. The reagent used in the third cleaning is 100 g / t of modified water glass to obtain tin flotation concentrate and tin flotation tailings.

[0065] S8. Reverse flotation for impurity removal: The tin flotation concentrate in step S7 is subjected to reverse flotation for impurity removal, adopting an open-circuit flotation process with 1 roughing, 2 cleaning, and tailings merging. The reagents used in roughing include 1500 g / t of sulfuric acid and 15 g / t of monohydric alcohol. No reagents are added in cleaning, and tin concentrate and arsenic concentrate are obtained.

[0066] Using the above process for treatment, for the feed containing 0.48% Sn and WO 3 0.14%, tin concentrate containing 22.32% Sn and WO 3 8.17% is obtained, and the recovery rates of tin and tungsten are 52.33% and 63.55% respectively.

[0067] Comparative Example 1

[0068] The difference from Example 1 is only that: step S5 is omitted, and other steps and conditions are the same as those in Example 1.

[0069] It is found that for the feed containing 0.43% Sn and WO 3 0.11%, tin concentrate containing 12.15% Sn and WO 3 3.74% is obtained, and the recovery rates of tin and tungsten are 40.33% and 57.55% respectively. The grades and recovery rates of tin and tungsten both decrease, mainly due to the interference of magnetic iron.

[0070] Comparative Example 2

[0071] The difference from Example 1 is only that: diesel is not added in step S7. The detailed steps are as follows: The sulfur-arsenic tailings in step S6 are subjected to tin flotation, adopting a closed-circuit flotation process with 1 roughing, 2 scavenging, and 3 cleaning. The reagents used in roughing include 400 g / t of lead nitrate, 800 g / t of benzohydroxamic acid (GYB), and 140 g / t of tributyl phosphate (TBP). The reagents used in scavenging 1 include 400 g / t of GYB and 80 g / t of TBP. The reagents used in scavenging 2 include 200 g / t of GYB and 40 g / t of TBP. The reagent used in cleaning 1 is 300 g / t of modified water glass. The reagent used in cleaning 2 is 200 g / t of modified water glass. The reagent used in cleaning 3 is 100 g / t of modified water glass. Tin flotation concentrate and tin flotation tailings are obtained, and other steps and conditions are the same as those in Example 1.

[0072] It is found that for the feed containing 0.43% Sn and WO 3 0.11%, tin concentrate containing 25.23% Sn and WO 3 6.32% is obtained, and the recovery rates of tin and tungsten are 43.15% and 55.27% respectively. The recovery rates of tin and tungsten decrease somewhat, mainly because some fine-grained minerals are insufficiently recovered by flotation.

[0073] Comparative Example 3

[0074] The difference from Example 1 is only that: in step S7, TBP is not added. The detailed steps are as follows: The sulfur-arsenic tailings in step S6 are subjected to tin flotation, adopting a closed-circuit flotation process of 1 roughing, 2 scavengings, and 3 cleanings. The reagents used in roughing include 400 g / t of lead nitrate, 800 g / t of benzohydroxamic acid (GYB), and 140 g / t of diesel. The reagents used in scavenging 1 include 400 g / t of GYB and 80 g / t of diesel. The reagents used in scavenging 2 include 200 g / t of GYB and 40 g / t of diesel. The reagent used in cleaning 1 is 300 g / t of modified water glass. The reagent used in cleaning 2 is 200 g / t of modified water glass. The reagent used in cleaning 3 is 100 g / t of modified water glass, obtaining tin flotation concentrate and tin flotation tailings. Other steps and conditions are the same as those in Example 1.

[0075] It was found that for the feed containing 0.43% Sn and WO 3 0.11%, a tin concentrate containing 27.32% Sn and WO 3 7.35% was obtained, and the recovery rates of tin and tungsten were 35.23% and 47.66% respectively. The recovery rates of tin and tungsten decreased significantly, mainly because the surface activity of the pulp was poor and the flotation efficiency was insufficient.

[0076] Comparative Example 4

[0077] The difference from Example 1 is only that: in step S7, benzohydroxamic acid is not added. The detailed steps are as follows: The sulfur-arsenic tailings in step S6 are subjected to tin flotation, adopting a closed-circuit flotation process of 1 roughing, 2 scavengings, and 3 cleanings. The reagents used in roughing include 400 g / t of lead nitrate, 470 g / t of C6-8 diesel, and 470 g / t of tributyl phosphate (TBP). The reagents used in scavenging 1 include 240 g / t of diesel and 240 g / t of TBP. The reagents used in scavenging 2 include 120 g / t of diesel and 120 g / t of TBP. The reagent used in cleaning 1 is 300 g / t of modified water glass. The reagent used in cleaning 2 is 200 g / t of modified water glass. The reagent used in cleaning 3 is 100 g / t of modified water glass, obtaining tin flotation concentrate and tin flotation tailings.

[0078] It was found that for the feed containing 0.43% Sn and WO 3 0.11%, a tin concentrate containing 1.10% Sn and WO 3 0.45% was obtained, and the recovery rates of tin and tungsten were 9.70% and 10.50% respectively. The recovery rates of tin and tungsten decreased significantly, mainly because diesel and TBP have no significant collecting property for tin and tungsten.

[0079] The description of the above embodiments is only used to help understand the technical solution and its core idea of the present invention. It should be noted that for those skilled in the art of this technology, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A ore dressing process for recovering tin from iron-tin ore gravity separation tailings, characterized in that: The steps include: S1. Cyclone classification: The iron-tin ore gravity separation tailings are classified by cyclone to obtain coarse and fine products. 50~100mm, pressure 0.1~0.3Mpa, 0.074mm classification efficiency 40%~60%; S2, classification: Classify the coarse grain product of step S1 to obtain three grain size products of +0.3 mm, -0.3+0.074 mm, and -0.074 mm; S3, grinding: grinding the +0.3 mm particle size product in step S2 to obtain a ground product; S4, concentration: the fine particle product in step S1 and the -0.074 mm product in step S2 are combined and concentrated to obtain overflow water and sediment; S5, weak magnetic separation: the grinding product of step S3 and the sand in step S4 are subjected to weak magnetic separation to obtain iron concentrate and iron tailings; S6, desulfurization and arsenic flotation: the sulfur tailings in step S5 are subjected to desulfurization and dearsenicization flotation to obtain sulfur arsenic concentrate and sulfur arsenic tailings; S7, tin flotation: subjecting the sulfur-arsenic tailings in step S6 to tin flotation to obtain tin flotation concentrate and tin flotation tailings; S8, reverse flotation and impurity removal: reverse flotation and impurity removal are performed on the tin flotation concentrate in step S7 to obtain tin concentrate and arsenic concentrate.

2. The ore dressing process for recovering tin from iron-tin ore gravity separation tailings according to claim 1, characterized in that: The iron-tin ore gravity separation tailings described in step S1 are tailings of the iron-tin ore after magnetic iron separation-zinc flotation-tin gravity separation, containing Sn 0.3%-0.5%, WO30.05%-0.15%, TFe 15%-20%, mFe 0.1%-0.8%, S 0.3%-0.8%, and As0.5%-1.5%.

3. The ore dressing process for recovering tin from iron-tin ore gravity separation tailings according to claim 1 or 2, characterized in that: In step S2, the coarse particle product is graded by a high-frequency sieve, which is a double-layer high-frequency sieve, wherein the Sn content is -0.074mm particle size>+0.3mm particle size>-0.3+0.074mm particle size.

4. The ore dressing process for recovering tin from iron-tin ore gravity separation tailings according to claim 1 or 2, characterized in that: The grinding fineness of the grinding product in step S3 is -0.074 mm, accounting for 60% to 80%.

5. The ore dressing process for recovering tin from iron-tin ore gravity separation tailings according to claim 1 or 2, characterized in that: The concentration of the sedimentation sand in step S4 is 25% to 40%, and the solid content of the overflow water is less than 0.5%.

6. The ore dressing process for recovering tin from iron-tin ore gravity separation tailings according to claim 1 or 2, characterized in that: The weak magnetic separation magnetic field strength in step S5 is 1500-3000 GS.

7. The ore dressing process for recovering tin from iron-tin ore gravity separation tailings according to claim 1 or 2, characterized in that: The desulfurization and dearsenication flotation described in step S6 adopts a closed-circuit flotation process of 1 roughing, 1 scavenging and 1 finishing. The reagents added in the roughing include 50-100 g / t of copper sulfate, 100-200 g / t of amyl xanthate and 30-50 g / t of monohydric alcohol, the reagent added in the scavenging is 50-100 g / t of amyl xanthate, and no reagent is added in the finishing.

8. The ore dressing process for recovering tin from iron-tin ore gravity separation tailings according to claim 1 or 2, characterized in that: The tin flotation described in step S7 adopts a closed-circuit flotation process of 1 roughing, 2 sweeping and 3 fineness. The reagents added in the roughing include 300-600g / t of lead nitrate, 500-1000g / t of benzohydroxamic acid, 50-100g / t of diesel and 50-100g / t of tributyl phosphate. The reagents added in the sweeping 1 include 200-400g / t of GYB, 30-60g / t of diesel and 30-60g / t of TBP. The reagents added in the sweeping 2 include 100-200g / t of GYB, 20-40g / t of diesel and 20-40g / t of TBP. The reagent added in the fineness 1 is 200-300g / t of water glass, the reagent added in the fineness 2 is 100-200g / t of water glass, and the reagent added in the fineness 3 is 50-100g / t of water glass.

9. The ore dressing process for recovering tin from iron-tin ore gravity separation tailings according to claim 1 or 2, characterized in that: The reverse flotation impurity removal in step S8 adopts an open circuit flotation process of combining 1 rough and 2 fine tailings. The reagents added in the roughing process include 1000-2000 g / t of sulfuric acid and 10-20 g / t of monohydric alcohol, and no reagents are added in the fine process.

10. The ore dressing process for recovering tin from iron-tin ore gravity separation tailings according to claim 1 or 2, characterized in that: Steps S5-S8 obtain tin concentrate, iron concentrate, sulfur-arsenic concentrate and arsenic concentrate. The tin concentrate contains 10%-30% Sn and 5%-10% WO3, with a Sn recovery rate of 40%-60% and a WO3 recovery rate of 50%-70%. The iron concentrate is mainly magnetite, the sulfur-arsenic concentrate is mainly pyrite and arsenopyrite, and the arsenic concentrate is mainly rhombohedral arsenic iron ore.

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