A beneficiation method for recovering fine fraction cassiterite from a shaker tailing

Abstract

The application relates to a beneficiation method for recovering fine tin ore from a shaking table tailing, and belongs to the technical field of beneficiation. The method comprises the following steps: (1) thickener concentration operation; (2) cyclone grading operation; (3) desliming treatment; (4) flotation desulfurization; (5) magnetic separation iron removal operation; (6) cyclone concentration operation: the iron removal tailing is sent into a concentration cyclone for concentration to obtain cyclone sand and cyclone overflow; and (7) tin ore flotation operation. The method can obtain the technical indexes that the tin fine product grade is greater than 35%, the tin rich middling grade is greater than 2.5%, and the tin comprehensive recovery rate is greater than 65% for the fine tin ore with uneven tin ore embedded particle size, poor monomer dissociation degree, high iron, high sulfur and high mud.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ore dressing, and particularly relates to a beneficiation method for recovering fine-grained cassiterite from shaking table tailings. BACKGROUND

[0002] In the global tin resource field, China occupies a prominent position with its rich reserves, but the complexity of resources also brings challenges. In China, the proportion of associated components in tin ore is as high as 88%, and single tin ore only accounts for a small part. With the deepening of mining, tin ore gradually shows the characteristics of being poor, fine and complex, which puts higher requirements on the extraction and recovery technology of tin ore. In particular, fine-grained and micro-fine-grained tin ore is difficult to recover due to its small particle size, close embedding and complex association.

[0003] In the field of mineral processing and beneficiation technology, the recovery of cassiterite, especially fine-grained and micro-fine-grained cassiterite, constitutes a major technical challenge and economic test. Traditional beneficiation methods are mainly based on physical methods such as gravity separation technology. In particular, the shaking table is widely used for the separation of tin ore because of its high enrichment ratio and direct production of concentrate. However, there are obvious limitations in processing fine-grained tin ore. The recovery effect of tin ore below-400 mesh is greatly discounted due to multiple factors such as particle size distribution, processing capacity, land area and recovery rate. In addition, tin ore is brittle and easy to break, and a large amount of micro-fine-grained tin ore is produced during the crushing and grinding process. The recovery difficulty is further increased due to the fine particle size, close embedding, complex association and high argillaceous content, resulting in low resource utilization and poor economic benefits.

[0004] Flotation, as another important beneficiation method, separates and enriches based on the difference in physical and chemical properties of mineral surfaces, and has potential advantages for the recovery of micro-fine-grained tin ore. However, single flotation method has problems such as high reagent consumption, high production cost, low grade of flotation concentrate, complex production process and unsatisfactory separation effect for severely argillized tin ore when processing high-iron high-sulfur high-argillaceous tin ore. Therefore, single gravity separation or flotation method cannot economically and efficiently solve the problem of recovering fine-grained tin ore with high iron, high sulfur and high argillaceous. SUMMARY

[0005] To solve or partially solve the problems in the related art, the present application provides a beneficiation method for recovering fine-grained cassiterite from shaking table tailings. The method adopts a combined process flow of thickener concentration-cyclone classification-centrifugal deargillization-flotation desulfurization-magnetic separation of iron-cyclone concentration-cassiterite flotation-vertical centrifuge pre-concentration-shaking table concentration to recover fine-grained cassiterite, and technical indicators of tin concentrate grade greater than 35%, tin middling grade greater than 2.5%, and tin comprehensive recovery rate greater than 65% are obtained. The present application provides technical support for efficient recovery of fine-grained tin ore with unevenly distributed particle size, poor monomer liberation, high iron, high sulfur and high argillaceous.

[0006] The specific steps of the present application are as follows:

[0007] (1) Thickener concentration operation: the tailings of the shaking table are sent to the thickener for concentration, the overflow water is returned to the production for recycling, and the underflow is sent to the classification cyclone for classification.

[0008] (2) Cyclone classification operation: the underflow after concentration in step 1 is sent to the classification cyclone for classification, and the coarse grade low grade ore and the fine grade high grade ore are separated, the cyclone sand coarse grade low grade ore is directly discarded, and the cyclone overflow fine grade high grade ore is sent to the desliming operation.

[0009] (3) Centrifuge desliming operation: the overflow fine grade ore of the classification cyclone in step 2 is sent to the centrifuge for desliming treatment, and the argillaceous components in the ore are removed (directly discarded), and the underflow is sent to the flotation desulfurization operation.

[0010] (4) Flotation desulfurization operation: the deslimed ore in step 3 is sent to the desulfurization flotation machine for flotation desulfurization operation, and the cassiterite and sulfur and other minerals are separated, the flotation concentrate is used as sulfur concentrate, and the flotation tailings are sent to the magnetic separation iron removal operation.

[0011] (5) Magnetic separation iron removal operation: the desulfurization flotation tailings in step 4 are sent to the magnetic separation operation for magnetic separation treatment to remove iron impurities, the magnetic separation concentrate is used as iron concentrate, and the magnetic separation tailings are sent to the cyclone concentration operation.

[0012] (6) Cyclone concentration operation: the iron removal tailings in step 5 are sent to the concentration cyclone for concentration to improve the concentration of tin flotation, the cyclone sand is sent to the tin flotation operation, and the cyclone overflow is returned to the centrifuge desliming operation.

[0013] (7) Tin flotation operation: the cyclone sand in step 6 is sent to the tin flotation operation for further flotation operation to obtain tin rough concentrate, and the flotation tailings are directly discarded.

[0014] (8) Centrifuge pre-enrichment operation: the tin rough concentrate is sent to the centrifuge for pre-enrichment, the centrifuge pre-enrichment operation concentrate is sent to the shaking table for cleaning, and the centrifuge pre-enrichment tailings are directly discarded.

[0015] (9) Shaking table cleaning operation: the concentrate after the centrifuge pre-enrichment in step 8 is sent to the shaking table for cleaning to produce tin concentrate and tin rich middlings.

[0016] Further, the thickener concentration operation in step 1, the thickener adopts a NXZ type center transmission high-efficiency thickener; the shaking table tailings have a concentration of 10%-15%, a +200 mesh particle size content of 20%-30%, a tin grade of 0.06%-0.1%, a -200 to +400 mesh particle size content of 20%-30%, a tin grade of 0.08%-0.1%, and a -400 mesh particle size content of 40%-60%, a tin grade of 0.2%-0.3%, and the ore after concentration by the thickener has a concentration of 25%-35%.

[0017] Further, the cyclone classification operation in step 2, the cyclone adopts a φ250mm hydrocyclone, and the classification overflow particle size content is controlled to be more than 70%.

[0018] Further, the centrifuge desliming operation in step 3, the centrifuge adopts a Falcon centrifuge, the centrifuge speed and throttle valve pressure parameters are precisely controlled, the -10um content in the ore after desliming by the centrifuge is controlled to be less than 10%, and the tin loss rate of the desliming operation is less than 8%.

[0019] Further, the flotation desulfurization operation in step 4, the process flow is a "one roughing + two scavenging + two cleaning" full flotation closed-circuit flow, the roughing, the first and second scavenging, and the first cleaning adopt a flotation machine as the separation equipment, the second cleaning adopts a flotation column as the separation equipment, the feeding concentration is controlled to be between 40%-45%, the reagent system is: a desulfurization activator 400-500g / t, a desulfurization collector 30-40g / t, and a frother 20-30g / t, and the sulfur grade of the desulfurization tailings is controlled to be less than 0.5%.

[0020] Further, the magnetic separation iron removal operation in step 5, the magnetic separator adopts a semi-counterflow wet type permanent magnetic separator, and the magnetic field strength is 200-500mT.

[0021] Further, the cyclone concentration operation in step 6, a φ75mm hydrocyclone is adopted, the sand concentration is controlled to be more than 50%, and the overflow concentration is controlled to be less than 15%.

[0022] Further, the cassiterite flotation operation in step 7, the process flow is a "two roughing + three scavenging + two cleaning" full flotation closed-circuit flow, and the separation equipment all adopts a flotation machine as the separation equipment, the feeding concentration is controlled to be between 50%-55%, the reagent system is: a cassiterite collector 400-800g / t and an auxiliary adjusting agent 100-200g / t, and the tin grade of the produced cassiterite rough and clean concentrates is between 2%-4%.

[0023] Further, the centrifuge in step 8 is pre-enrichment operation, the centrifuge adopts SL type centrifuge, the speed of centrifuge, feeding time and ore flow, rinsing water quantity, flushing water quantity and other parameters are precisely controlled, the process flow is "one rough + one fine + one sweep" closed circuit process, the feeding concentration is between 10% and 15%, the pre-enrichment operation concentrate enrichment ratio is 4 to 8 times, and the tin grade of tailings is controlled below 0.5%.

[0024] Further, the shaking table in step 9 is a table, which is a cloud tin table, and the bed surface type has fine sand bed, grooved bed and micro fine mud bed; a total of 7 single-column shaking tables are configured, 1-3# are fine sand beds, 4-6# are grooved beds, and 7# is a micro fine mud table; the matched hydraulic classification box is a cloud tin hydraulic classification box, which is connected with the shaking table through a channel (the overall slope is 3 degrees), 1-2# is YX-150, 3-4# is YX-200, 5# is YX-400, and 6-7# is YX-600; after the shaking table selection, the tin stone rough concentrate produces tin concentrate with tin grade greater than 35% and tin middlings with tin grade greater than 2.5%.

[0025] Further, the sulfur removal in step 4 is an activation agent, which can be copper sulfate, sulfuric acid, hydrochloric acid and the like, and the copper sulfate is diluted to 5%-15% before use, and the sulfuric acid and hydrochloric acid are directly added with the original solution; the sulfur removal collector can be a xanthate collector, a black drug collector or other collectors, which is diluted to 5%-15% before use; the foaming agent is pine oil, which is directly added with the original solution.

[0026] Further, the tin stone flotation in step 7 is a tin stone collector, which can be fatty acid, arsine acid, alkyl hydroxyl oxime acid, alkyl sulfonated succinic acid and the like, which is mixed with a certain proportion of a solubilizing agent (sodium hydroxide or sodium carbonate) to better dissolve in water, and is diluted to 5%-15% before use, and the auxiliary collector is an alcohol ester mixture, which is directly added with the original solution.

[0027] The beneficial effects of the present application are:

[0028] (1) The "cyclone classification + centrifuge desliming" innovative combined process of the application realizes the simplification and optimization of the process flow compared with the traditional single cyclone method, not only ensures that the classification particle size accurately meets the high standard of flotation, but also completely removes the slime minerals, effectively solves the problem of tin stone loss caused by mechanical entrainment of cyclone. In addition, the process integrates advanced pretreatment technologies such as cyclone classification, centrifuge desliming, flotation desulfurization and magnetic separation iron removal, and builds a set of efficient combined pretreatment system, which significantly weakens the interference of slime, sulfur minerals and magnetic minerals on the tin stone selection process, and guarantees the efficient and stable operation of the subsequent recovery process. At the same time, the significant reduction of reagent consumption is realized, and the dual improvement of cost benefit is achieved.

[0029] (2) The application uses cyclone to efficiently concentrate the tailings of magnetic separation, which solves the problem of low concentration and secondary slime interference in the tin stone flotation process, not only stabilizes the key parameter of tin stone flotation operation-floatation time, but also significantly reduces the consumption of reagents, realizes the dual optimization of resource utilization and cost control, and lays a solid foundation for the stable operation and efficiency improvement of tin ore flotation process.

[0030] (3) The application creatively applies centrifuge to the pre-enrichment process of tin stone rough concentrate, which not only greatly enhances the stability of the process compared with the traditional flotation column enrichment technology, but also significantly improves the enrichment ratio and recovery rate, realizing the efficient utilization of resources. What is particularly important is that this technology effectively solves the problem of insufficient enrichment ratio in the tin stone flotation process, thereby improving the recovery efficiency of table concentration operation, and successfully overcoming the problem of not being able to produce qualified tin-rich middlings.

[0031] (4) The application produces tin concentrate and tin-rich middlings by introducing table concentration process, successfully coping with the challenge of unevenly distributed tin stone. In view of the problem that part of the tin stone still exists in the form of intergrowth and inclusions after fine grinding, and the monomer dissociation degree is limited, the process significantly improves the tin concentrate grade and tin comprehensive recovery rate. This combined process not only meets the technical problem of efficient comprehensive recovery of fine-grained tin stone, but also shows excellent economic benefits in actual application. BRIEF DESCRIPTION OF DRAWINGS

[0032] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which similar reference characters refer to similar elements throughout the several views.

[0033] Figure 1 is the process flow schematic diagram in embodiment 1 of the application. DETAILED DESCRIPTION

[0034] Embodiments of the present application will be described in more detail below with reference to the embodiments. Although embodiments show the embodiments of the present application, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0035] Example 1

[0036] By using the process shown in the flow chart, the fine tin stone in the shaking table tailings of a multi-metallic sulfide ore dressing plant in Yunnan is recovered, and the specific operation is as follows: Figure 1 The raw ore in this area is a multi-metallic ore deposit mainly composed of copper, tin and iron, and the ore composition is complex. The raw ore is crushed and ground to a-200 mesh content of 65%, and the process of flotation for copper selection, flotation for sulfur selection, magnetic separation for iron selection, and shaking table for tin selection is used for separation. After separation, the shaking table tailings for tin selection has a concentration of 12.5%, a +200 mesh content of 26.8%, a tin grade of 0.063%, a-200~+400 mesh content of 24.3%, a tin grade of 0.084%, and a-400 mesh content of 48.9%, a tin grade of 0.214%.

[0037] The fine tin stone in the shaking table tailings is recovered by using the ore dressing method of the present application. The shaking table tailings for tin selection is self-flowing to the center transmission high-efficiency thickener for concentration. The overflow water produced is returned to the production cycle for recycling. The concentrated ore (concentration 30.7%) is transported to the φ250mm hydrocyclone by slurry pump for classification. The cyclone operates at a pressure of 45KPa. The classified sand is directly discarded. The classified overflow (-400 mesh content 80.2%, concentration 15.2%) is self-flowing to the centrifuge desliming buffer tank and then enters the Falcon centrifuge for desliming. The centrifuge drum rotates at 812 revolutions per minute, and the throttle valve operates at a pressure of 1300KPa. The-10um content in the deslimed ore is 6.3%. The produced slime is directly discarded.

[0038]

[0039] ​The deslimed product flows to the 1# mixing tank by itself, water is added to the 1# mixing tank to dilute the ore concentration to 43%, and 430g / t of copper sulfate solution with a concentration of 6.2% is added to activate the sulfide minerals, after activation, the minerals enter the 2# mixing tank, 25g / t of ethyl xanthate solution with a concentration of 5% and 15g / t of pine oil are sequentially added to the 2# mixing tank, after the ore is slurried, it is fed into the flotation machine for "one roughing, two scavenging, and two cleaning" full flotation closed circuit process to remove sulfur, the intermediate products are sequentially returned to the corresponding operation, among which the roughing produces a roughing concentrate and a roughing tailings, the first scavenging is sequentially adding 10g / t of ethyl xanthate solution with a concentration of 5% and 10g / t of pine oil to the roughing tailings, producing a first scavenging concentrate and a first scavenging tailings, the second scavenging does not add any reagent, producing a second scavenging concentrate and a second scavenging tailings, the first cleaning is adding 5g / t of pine oil to the roughing concentrate, producing a first cleaning concentrate and a first cleaning tailings, the first cleaning concentrate is transported to the second cleaning (flotation column) by a slurry pump, the second cleaning does not add any reagent, producing a second cleaning tailings and a final sulfur concentrate, the sulfur removal tailings contain 0.323% sulfur.

[0040] The sulfur-free tailings are fed into a semi-counterflow permanent magnetic separator to remove iron, with a magnetic field strength of 500 mT, to produce iron concentrate and iron tailings. The iron tailings are transported to a φ75 mm hydrocyclone by a slurry pump for concentration, with a cyclone operating pressure of 270 KPa. The overflow (concentration of 10.4%) is fed into a centrifuge desliming buffer tank, and the cyclone underflow (concentration of 57%) is fed into a 3# stirring tank. Dilution water is added to the 3# stirring tank to adjust the concentration of the slurry to 53%. A tin ore collector YK-SN (alkyl hydroxamic acid collector, prepared by mixing with sodium hydroxide at a ratio of 4:1) solution with a concentration of 6% is added at a rate of 400 g / t. After sufficient stirring, the slurry is fed into a 4# stirring tank. An auxiliary collector SN-F is added at a rate of 100 g / t. The slurry is then fed into a flotation machine for tin ore flotation in a "two roughing, three scavenging, and two cleaning" closed-circuit process. The intermediate products are returned to the corresponding operations in turn. The first roughing produces a first roughing concentrate and a first roughing tailings. The second roughing is performed on the first roughing tailings by adding a tin ore collector YK-SN (alkyl hydroxamic acid collector, prepared by mixing with sodium hydroxide at a ratio of 4:1) solution with a concentration of 6% at a rate of 100 g / t, to produce a second roughing concentrate and a second roughing tailings. The first scavenging is performed on the second roughing tailings by adding a tin ore collector YK-SN (alkyl hydroxamic acid collector, prepared by mixing with sodium hydroxide at a ratio of 4:1) solution with a concentration of 6% at a rate of 50 g / t, to produce a first scavenging concentrate and a first scavenging tailings. The second scavenging is performed on the first scavenging tailings by adding a tin ore collector YK-SN (alkyl hydroxamic acid collector, prepared by mixing with sodium hydroxide at a ratio of 4:1) solution with a concentration of 6% at a rate of 50 g / t, to produce a second scavenging concentrate and a second scavenging tailings. The third scavenging is performed without adding any reagents, to produce a third scavenging concentrate and a third scavenging tailings. The first cleaning is performed on the mixture of the first roughing concentrate and the second roughing concentrate by adding an auxiliary collector SN-F at a rate of 50 g / t, to produce a first cleaning concentrate and a first cleaning tailings. The second cleaning is performed without adding any reagents, to produce a second cleaning tailings and a tin ore rough concentrate. The tin ore rough concentrate has a tin grade of 2.305%.

[0041] The tin ore rough concentrate (concentration of 12.4%) is fed into a centrifuge pre-concentration buffer tank to enter a "one roughing, one cleaning, and one scavenging" centrifuge pre-concentration closed-circuit process. The intermediate products are returned to the corresponding process in turn and transported by a slurry pump. The roughing SL-type centrifuge operating parameters are a feeding time of 110 seconds, an interval time of 5 seconds, a flushing time of 20 seconds, a drum rotating speed of 210 r / min, and a rinsing water amount of 3 m 3 / h. The roughing produces a roughing concentrate and a roughing tailings. The scavenging SL-type centrifuge operating parameters are a feeding time of 100 seconds, an interval time of 5 seconds, a flushing time of 22 seconds, a drum rotating speed of 180 r / min, and a rinsing water amount of 2.5 m 3 / h. The scavenging produces a scavenging concentrate and a scavenging tailings, with a tin grade of 0.207% in the scavenging tailings. The cleaning SL-type centrifuge operating parameters are a feeding time of 90 seconds, an interval time of 5 seconds, a flushing time of 18 seconds, a drum rotating speed of 230 r / min, and a rinsing water amount of 4 m3 The pre-concentration concentrate is automatically flowed into a buffer tank of the shaking table feed tank, and is slowly and uniformly fed into a hydraulic classification tank.

[0042] The pre-concentration concentrate is automatically flowed into a buffer tank of the shaking table feed tank, and is slowly and uniformly fed into a hydraulic classification tank.

[0043] Example 2

[0044] The beneficiation method for recovering cassiterite in the fine particle size of the shaking table tailings of a multi-metal sulfide ore dressing plant in a certain area is as follows:

[0045] The shaking table tin tailings in the area have a concentration of 13.2%, a +200 mesh particle size content of 21.8%, a tin grade of 0.071%, a -200 to +400 mesh particle size content of 22.5%, a tin grade of 0.090%, and a -400 mesh particle size content of 55.7%, a tin grade of 0.227%.

[0046] The beneficiation method is applied to recover the fine particle size cassiterite in the shaking table tailings, the shaking table tin tailings are automatically flowed into a central transmission high-efficiency thickener for concentration, the overflow water produced is returned to production for recycling, the concentrated ore (concentration 32.4%) is transported to a φ250mm hydrocyclone for classification by using a slurry pump, the cyclone operates at a pressure of 47KPa, the classified sand is directly discarded, the classified overflow (-400 mesh content 85.1%, concentration 16.4%) is automatically flowed into a Falcon centrifuge for desliming after entering a centrifuge desliming buffer tank, the centrifuge drum rotates at a speed of 820r / min, the throttle valve operates at a pressure of 1450KPa, the -10um content in the deslimed ore is 7.1%, and the produced slime is directly discarded.

[0047] The deslimed product flows to the 1# mixing tank by itself, water is added to the 1# mixing tank to dilute the ore concentration to 44%, and 450g / t of copper sulfate solution with a concentration of 6.6% is added to activate the sulfide minerals, after activation, the minerals enter the 2# mixing tank, 27g / t of ethyl xanthate solution with a concentration of 3% and 15g / t of pine oil are sequentially added to the 2# mixing tank, after the ore is slurried, it is fed into the flotation machine for "one roughing, two scavenging, and two cleaning" full flotation closed circuit process to remove sulfur, the intermediate products are sequentially returned to the corresponding operation, among which the roughing produces a roughing concentrate and a roughing tailings, the first scavenging is sequentially adding 13g / t of ethyl xanthate solution with a concentration of 5% and 10g / t of pine oil to the roughing tailings, producing a first scavenging concentrate and a first scavenging tailings, the second scavenging does not add any reagent, producing a second scavenging concentrate and a second scavenging tailings, the first cleaning is adding 5g / t of pine oil to the roughing concentrate, producing a first cleaning concentrate and a first cleaning tailings, the first cleaning concentrate is transported to the second cleaning (flotation column) by a slurry pump, the second cleaning does not add any reagent, producing a second cleaning tailings and a final sulfur concentrate, the sulfur removal tailings contain 0.213% sulfur.

[0048] The sulfur-free tailings are fed into a semi-counterflow permanent magnetic separator to remove iron, with a magnetic field strength of 500 mT, to produce iron concentrate and iron tailings. The iron tailings are transported to a φ75 mm hydrocyclone by a slurry pump for concentration, with a cyclone operating pressure of 275 KPa. The overflow (concentration of 13.4%) is fed into a centrifuge desliming buffer tank, and the cyclone underflow (concentration of 56.3%) is fed into a 3# stirring barrel. Dilution water is added to the 3# stirring barrel to adjust the concentration of the slurry to 53%. A 300 g / t solution of tin ore collector SN-705 (alkyl hydroxamic acid collector, prepared by mixing with sodium hydroxide at a ratio of 3:1) with a concentration of 7% is added. After sufficient stirring, the slurry is fed into a 4# stirring barrel. An auxiliary collector SN-F is added to the 4# stirring barrel at a dosage of 100 g / t. The slurry is then fed into a flotation machine for a "two roughing, three scavenging, and two cleaning" closed-circuit process for tin ore flotation. The intermediate products are returned to the corresponding operations in sequence. The first roughing produces a first roughing concentrate and a first roughing tailings. The second roughing is performed on the first roughing tailings by adding a 80 g / t solution of tin ore collector SN-705 (alkyl hydroxamic acid collector, prepared by mixing with sodium hydroxide at a ratio of 3:1) with a concentration of 7%, to produce a second roughing concentrate and a second roughing tailings. The first scavenging is performed on the second roughing tailings by adding a 50 g / t solution of tin ore collector SN-705 (alkyl hydroxamic acid collector, prepared by mixing with sodium hydroxide at a ratio of 3:1) with a concentration of 7%, to produce a first scavenging concentrate and a first scavenging tailings. The second scavenging is performed on the first scavenging tailings by adding a 50 g / t solution of tin ore collector SN-705 (alkyl hydroxamic acid collector, prepared by mixing with sodium hydroxide at a ratio of 3:1) with a concentration of 7%, to produce a second scavenging concentrate and a second scavenging tailings. The third scavenging is performed without adding any reagents, to produce a third scavenging concentrate and a third scavenging tailings. The first cleaning is performed on the mixture of the first roughing concentrate and the second roughing concentrate by adding an auxiliary collector SN-F at a dosage of 50 g / t, to produce a first cleaning concentrate and a first cleaning tailings. The second cleaning is performed without adding any reagents, to produce a second cleaning tailings and a tin ore rough concentrate. The tin ore rough concentrate contains 3.105% tin.

[0049] The tin ore rough concentrate (concentration of 11.6%) is fed into a centrifuge pre-concentration buffer tank for a "one roughing, one cleaning, and one scavenging" centrifuge pre-concentration closed-circuit process. The intermediate products are returned to the corresponding processes by a slurry pump. The roughing SL-type centrifuge operating parameters are a feeding time of 115 seconds, an interval time of 5 seconds, a flushing time of 20 seconds, a drum speed of 200 r / min, and a rinsing water amount of 3 m 3 / h, to produce a roughing concentrate and a roughing tailings. The scavenging SL-type centrifuge operating parameters are a feeding time of 105 seconds, an interval time of 5 seconds, a flushing time of 22 seconds, a drum speed of 190 r / min, and a rinsing water amount of 2.5 m 3 / h, to produce a scavenging concentrate and a scavenging tailings containing 0.221% tin. The cleaning SL-type centrifuge operating parameters are a feeding time of 95 seconds, an interval time of 5 seconds, a flushing time of 18 seconds, a drum speed of 225 r / min, and a rinsing water amount of 4 m3 The pre-concentration of the centrifuge enriches the concentrate and the concentrate contains 15.473% of tin.

[0050] The pre-concentration of the centrifuge enriches the concentrate and the concentrate contains 15.473% of tin.

[0051] Example 3

[0052] The tin ore dressing method for recovering the fine particle grade cassiterite in the shaking table tailings of a sulfide ore dressing plant in a certain area is specifically as follows:

[0053] The concentration of the shaking table tin ore dressing tailings in the area is 12.4%, the content of the +200 mesh particle grade is 23.4%, the tin grade is 0.065%, the content of the -200 to +400 mesh particle grade is 23.1%, the tin grade is 0.086%, and the content of the -400 mesh particle grade is 53.5%, the tin grade is 0.246%.

[0054] The application of the ore dressing method of the application to the recovery of the fine particle grade cassiterite in the shaking table tailings is as follows: the shaking table tin ore dressing tailings are self-flowed into the central transmission high-efficiency thickener for concentration, the overflow water produced is returned to the production for recycling, the concentrated ore (concentration 35.1%) is transported to the φ250mm type hydrocyclone for classification by using a slurry pump, the cyclone operates at a pressure of 50KPa, the classified sand is directly discarded, the classified overflow (-400 mesh content 84.3%, concentration 17.2%) is self-flowed into the Falcon centrifuge for desliming after entering the centrifuge desliming buffer tank, the centrifuge drum rotates at a speed of 825r / min, the throttle valve operates at a pressure of 1350KPa, the -10um content in the deslimed ore is 7.5%, and the produced slurry is directly discarded.

[0055] The deslimed product flows to the 1# mixing tank by itself, water is added to the 1# mixing tank to dilute the ore concentration to 41%, while adding 420g / t of copper sulfate solution with a concentration of 7.6% to activate the sulfide minerals, after sufficient stirring, it enters the 2# mixing tank, 30g / t of ethyl xanthate solution with a concentration of 8% and 15g / t of pine oil are added to the 2# mixing tank in turn, after the ore is slurried, it is fed into the flotation machine for "one roughing, two scavenging and two cleaning" full flotation closed circuit process to remove sulfur, the intermediate products are normally returned to the corresponding operation in turn, among which the roughing produces roughing concentrate and roughing tailings, the first scavenging adds 10g / t of ethyl xanthate solution with a concentration of 8% and 10g / t of pine oil in the roughing tailings in turn, producing scavenging one concentrate and scavenging one tailings, the second scavenging does not add any reagent, producing scavenging two concentrate and scavenging two tailings, the first cleaning adds 5g / t of pine oil in the roughing concentrate, producing cleaning one concentrate and cleaning one tailings, the cleaning one concentrate is transported to the second cleaning (flotation column) by a slurry pump, the second cleaning does not add any reagent, producing cleaning two tailings and final sulfur concentrate, the sulfur removal tailings contain 0.274% sulfur grade.

[0056] The sulfur-free tailings are fed into a semi-counterflow permanent magnetic separator to remove iron, with a magnetic field strength of 350 mT, to produce iron concentrate and iron tailings. The iron tailings are transported to a φ75 mm hydrocyclone by a slurry pump for concentration, with a cyclone operating pressure of 290 KPa. The overflow (concentration of 12.7%) is fed into a centrifuge pre-concentration buffer tank, and the cyclone underflow (concentration of 57.2%) is fed into a 3# stirring tank. Dilution water is added to the 3# stirring tank to adjust the concentration of the slurry to 52%. A 280 g / t solution of tin ore collector SN-705 (alkyl hydroxamic acid collector, prepared by mixing with sodium hydroxide at a ratio of 2:1) with a concentration of 8% is added. After sufficient stirring, the slurry is fed into a 4# stirring tank. An auxiliary collector SN-F is added to the 4# stirring tank at a dosage of 100 g / t. The slurry is then fed into a flotation machine for a "two roughing, three scavenging, and two cleaning" full flotation closed circuit process for tin ore flotation. The intermediate products are returned to the corresponding operations in sequence. The first roughing produces a first roughing concentrate and a first roughing tailings. The second roughing is performed by adding a 100 g / t solution of tin ore collector SN-705 (alkyl hydroxamic acid collector, prepared by mixing with sodium carbonate at a ratio of 2:1) with a concentration of 8% to the first roughing tailings, to produce a second roughing concentrate and a second roughing tailings. The first scavenging is performed by adding a 50 g / t solution of tin ore collector SN-705 (alkyl hydroxamic acid collector, prepared by mixing with sodium carbonate at a ratio of 2:1) with a concentration of 8% to the second roughing tailings, to produce a first scavenging concentrate and a first scavenging tailings. The second scavenging is performed by adding a 50 g / t solution of tin ore collector SN-705 (alkyl hydroxamic acid collector, prepared by mixing with sodium carbonate at a ratio of 3:1) with a concentration of 8% to the first scavenging tailings, to produce a second scavenging concentrate and a second scavenging tailings. The third scavenging is performed without adding any reagents, to produce a third scavenging concentrate and a third scavenging tailings. The first cleaning is performed by adding an auxiliary collector SN-F at a dosage of 50 g / t to the mixture of the first roughing concentrate and the second roughing concentrate, to produce a first cleaning concentrate and a first cleaning tailings. The second cleaning is performed without adding any reagents, to produce a second cleaning tailings and a tin ore rough concentrate. The tin ore rough concentrate has a tin grade of 2.405%.

[0057] The tin ore rough concentrate (concentration of 13.6%) is fed into a centrifuge pre-concentration buffer tank to enter a "one roughing, one cleaning, and one scavenging" centrifuge pre-concentration closed circuit process. The intermediate products are returned to the corresponding processes by a slurry pump. The roughing SL-type centrifuge operating parameters are a feeding time of 117 seconds, an interval time of 5 seconds, a flushing time of 21 seconds, a drum rotating speed of 195 r / min, and a rinsing water amount of 2.5 m 3 / h. The roughing produces a roughing concentrate and a roughing tailings. The scavenging SL-type centrifuge operating parameters are a feeding time of 125 seconds, an interval time of 5 seconds, a flushing time of 22 seconds, a drum rotating speed of 185 r / min, and a rinsing water amount of 2.5 m 3 / h, the sweep tailings containing 0.196% tin grade; the running parameters of the SL type centrifugal concentrator are as follows: feeding time 105 seconds, interval time 5 seconds, flushing time 19 seconds, drum rotating speed 220 r / min, and rinsing water amount 3.5 m 3 / h; the sweep tailings and the sweep concentrate are output, and the sweep concentrate contains 12.248% tin grade.

[0058] The pre-concentration concentrate of the centrifugal concentrator flows into the feeding buffer tank of the shaking table, is slowly and uniformly fed into the hydraulic classification tank, is classified under the action of gravity, and sinks into the feeding tank of the shaking table to be selected by the shaking table, so that the tin concentrate containing 35.521% tin grade and the tin-rich middlings containing 3.35% tin grade are output, and the comprehensive recovery rate is 68.08%.

[0059] The above has described the embodiments of the present application, and the above description is exemplary, is not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, practical application, or improvement of the technology in the market, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. A mineral processing method for recovering fine-grained cassiterite from shaking table tailings, characterized in that, Includes the following steps: (1) Thickening operation: The tailings from the shaking table are fed into the thickener for thickening to obtain thickened underflow with a concentration of 25% to 35%; (2) Hydrocyclone classification operation: The dense underflow is fed into the classifying hydrocyclone for classification operation to obtain coarse-grained low-grade ore material in the hydrocyclone underflow and fine-grained high-grade ore material in the hydrocyclone overflow; during the classification operation, the content of -400 mesh in the classification overflow is controlled above 70%, the underflow concentration is controlled above 50%, and the overflow concentration is controlled below 15%. (3) The fine-grained high-grade ore is fed into a centrifuge for desliming treatment. The -10um content in the ore after desliming is controlled to be below 10%. (4) The deslimed ore is fed into a desulfurization flotation machine for flotation and desulfurization to obtain flotation concentrate, sulfur concentrate and flotation tailings; The flotation desulfurization process is a closed-loop process of "one roughing + two scavenging + two cleaning". The reagent system is 400-500g / t of desulfurization activator, 30-40g / t of desulfurization collector, 20-30g / t of frother, and the sulfur content of the desulfurization tailings is controlled below 0.5%. (5) Magnetic separation for iron removal: The flotation tailings are subjected to magnetic separation to obtain magnetic concentrate as iron concentrate and iron removal tailings; (6) Hydrocyclone thickening operation: Iron-removed tailings are fed into a thickening hydrocyclone for thickening to obtain hydrocyclone underflow and hydrocyclone overflow; (7) Cassiterite flotation operation: The cyclone sediment enters the cassiterite flotation operation for further flotation to obtain cassiterite rough concentrate; the process flow of the cassiterite flotation operation is a closed-loop process of "two roughing + three scavenging + two cleaning" flotation; the reagent system is: cassiterite collector 400-800g / t, auxiliary modifier 100-200g / t, and the grade of the cassiterite rough concentrate produced is 2%-4%; (8) Centrifuge pre-enrichment operation: The cassiterite rough concentrate is fed into a centrifuge for pre-enrichment to obtain the pre-enriched cassiterite rough concentrate; The centrifuge pre-enrichment process is a closed-loop process of "one roughing + one cleaning + one scavenging", with a feed concentration of 10% to 15%, a concentrate enrichment ratio of 4 to 8 times, and a tin content in the tailings controlled below 0.5%. (9) Shaking table refining operation: The pre-enriched cassiterite rough concentrate is fed into a shaking table for refining, which yields high-grade tin concentrate and tin-rich medium ore.

2. The beneficiation method for recovering fine-grained cassiterite from shaking table tailings according to claim 1, characterized in that, The desulfurization activator is copper sulfate, sulfuric acid, or hydrochloric acid. Copper sulfate is diluted with water to a mass percentage concentration of 5% to 15% before use. Sulfuric acid and hydrochloric acid are added directly in their original solutions. The desulfurization collector is a xanthate collector or a black powder collector, which is diluted with water to a mass percentage concentration of 5% to 15% before use. The foaming agent is pine oil, which is added directly in its original solution.

3. The mineral processing method for recovering fine-grained cassiterite from shaking table tailings according to claim 1, characterized in that, The cassiterite collector is a fatty acid, arsenoic acid, alkyl hydroxamic acid, or alkyl sulfonated succinic acid. Before use, it is mixed with a certain proportion of sodium hydroxide or sodium carbonate as a co-solvent, and diluted with water to a mass percentage concentration of 5% to 15%. The auxiliary collector is an alcohol-ester mixture, which is added directly from the undiluted solution.

4. The mineral processing method for recovering fine-grained cassiterite from shaking table tailings according to claim 1, characterized in that, In step (1), the concentration of tailings from the shaking table is 10%–15%; the content of +200 mesh particles is 20%–30% and the tin grade is 0.06%–0.1%; the content of -200–+400 mesh particles is 20%–30% and the tin grade is 0.08%–0.1%; and the content of -400 mesh particles is 40%–60% and the tin grade is 0.2%–0.3%.

5. A mineral processing method for recovering fine-grained cassiterite from shaking table tailings according to claim 4, characterized in that, The method can achieve a final tin grade greater than 35%, a tin-rich medium ore grade greater than 2.5%, and a tin overall recovery rate greater than 65%.

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