Method for high-valued comprehensive utilization of zinc smelting kiln slag

Abstract

The invention provides a method for high-valued comprehensive utilization of zinc smelting kiln slag. Comprising the following steps that crushed kiln slag is subjected to a magnetic separation process, magnetic materials and non-magnetic materials are separated, the non-magnetic materials are screened through a jigger and a spiral classifier, particle coke is produced, and after the magnetic materials are subjected to ball milling, iron ore concentrate, carbon fine powder and silver concentrate are separated out through a magnetic separation and flotation process. According to the high-valued comprehensive utilization method for the zinc smelting kiln slag, carbon and emission can be reduced, high-valued utilization of the kiln slag can be achieved, the process and equipment are relatively simple, and economic benefits are high.

Description

Technical Field

[0001] The invention relates to the technical field of zinc smelting slag utilization, and in particular to a method for high-value comprehensive utilization of zinc smelting slag. Background Art

[0002] The comprehensive utilization of mineral resources in my country has been one of the key research directions in recent years. With the development of my country's zinc smelting industry, the amount of zinc kiln slag produced has been increasing. The recovery of valuable elements from zinc kiln slag has a strategic significance that cannot be underestimated. Zinc kiln slag is a valuable resource. It is currently mainly used for paving roads and cement fillers. Most of it has not been used reasonably and is piled up in various zinc smelting plants across the country, which not only occupies a large area of ​​land resources, but also easily causes environmental pollution and wastes social resources. The non-ferrous metals such as Zn, Pb, and Cu in zinc kiln slag enter the water or soil, causing serious pollution to the environment. It not only directly affects the living environment of aquatic plants and animals, but also directly or indirectly affects human life through the food chain. Therefore, it is of great significance to carry out research on comprehensive recovery and treatment technology of zinc kiln slag, which is mainly manifested in: ① Zinc kiln slag contains valuable metal elements and coke. Carrying out research on comprehensive recovery and treatment technology of zinc kiln slag can not only obtain greater economic benefits, but also achieve energy conservation and emission reduction, and promote the comprehensive utilization of solid waste. ② Comprehensive recovery of valuable heavy metal elements such as Ag, Zn, Pb, Cu, etc. from zinc kiln slag can not only improve the quality of living environment and protect people's health, but also help to make full use of mineral resources, improve the technological content of enterprise production and reduce production costs.

[0003] Major domestic zinc smelting enterprises have not yet formed an effective technical path and engineering application for achieving carbon emission reduction through the high-value utilization of kiln slag. For example, Yuguang Gold and Lead (about 300,000 tons of kiln slag / a), Southern Nonferrous (200,000 tons of kiln slag / a), Huludao Zinc Industry Co., Ltd. (100,000 tons / a), Chihong Zinc and Germanium (200,000 tons of kiln slag / a) and other major domestic zinc smelting enterprises all process kiln slag through external sales. At the same time, there are no large-scale enterprises in China for the high-value utilization of kiln slag, and the processing capacity is limited in the primary utilization of kiln slag. Moreover, in the existing technology, single-stage magnetic separation is mainly used for the preliminary separation of Fe and C, resulting in low C utilization and low comprehensive utilization of valuable metals (Ag, Cu, etc.).

[0004] In recent years, researchers have conducted a lot of experimental research on the comprehensive recovery of zinc kiln slag, but there are still problems such as low recovery rate, low ore grade, and high processing cost. How to find a more reasonable, economical, and effective recovery process has always been the direction of common efforts of researchers.

[0005] Therefore, there is an urgent need to develop an effective method for the high-value comprehensive utilization of zinc smelting slag to ensure that a large amount of slag resources can be comprehensively recycled, improve resource utilization, and reduce the impact on the environment. Summary of the invention

[0006] In order to solve the above-mentioned technical problems, the purpose of the present invention is to provide a method for high-value comprehensive utilization of zinc smelting slag which can save energy and reduce emissions, has low cost, high economic benefits and is simple in method.

[0007] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is: a method for high-value comprehensive utilization of zinc smelting slag, comprising:

[0008] Zinc smelting slag pretreatment: The zinc smelting slag is screened and crushed into slag fragments with a particle size of less than 2 cm for standby use;

[0009] Recovery of coke pellets: The crushed slag with a particle size of less than 2 cm is subjected to two-stage wet magnetic separation. The non-magnetic materials after magnetic separation are successively passed through a jig and a spiral classifier to screen out coke pellets. The magnetic materials after magnetic separation are used as raw materials for subsequent comprehensive recovery processes and are reserved for future use.

[0010] Iron concentrate recovery: the magnetic material after magnetic separation is passed through the wet first ball mill to obtain a coarse material with a grinding fineness of -200 mesh accounting for 35% to 45%; the obtained coarse material is passed through two stages of wet magnetic separation, and the magnetic concentrate after magnetic separation is filtered through a belt filter to obtain iron concentrate; the magnetic tailing material after magnetic separation is reserved;

[0011] Carbon concentrate recovery: The magnetic tailings after magnetic separation are passed through a wet second ball mill to obtain fine materials with a grinding fineness of -200 mesh accounting for 75% to 85%; the fine materials are subjected to a first coarse selection and a first fine selection in sequence, and a collector and a foaming agent are added to recover the carbon. The carbon concentrate obtained after fine selection is filtered with a ceramic filter to obtain carbon concentrate; the fine carbon concentrate tailings are reserved for later use;

[0012] Silver concentrate recovery: The selected carbon concentrate tailings are sequentially subjected to one-stage roughing, two-stage concentrating and two-stage scavenging, and silver is recovered by adding collectors and frothers. The slurry obtained after scavenging is filtered by a chamber filter to obtain silver concentrate; the silver concentrate tailings after scavenging are reserved for later use;

[0013] Tailings recovery: The silver concentrate tailings after scavenging are filtered through a ceramic filter to obtain tailings.

[0014] Furthermore, in the pellet coke recovery process, the effluent from the jig and spiral classifier enters the thickener, and after gravity sedimentation and concentration in the thickener, the bottom slag is controlled to obtain pellet coke again.

[0015] Furthermore, in the iron concentrate recovery process, the magnetic concentrate after magnetic separation is filtered through a belt filter, and the obtained filtrate is sent to the chamber filter in the silver concentrate recovery process for filtration, and the silver concentrate is recovered together.

[0016] Furthermore, the carbon concentrate recovery process also includes: firstly feeding the fine material with a grinding fineness of -200 mesh accounting for 75% to 85% into the hydrocyclone, and then sequentially performing a roughing selection and a fine selection on the slurry overflowing from the hydrocyclone; and returning the sediment produced in the hydrocyclone to the first ball mill.

[0017] Furthermore, the tailings recovery process includes: subjecting the silver concentrate tailings after scavenging to strong magnetic separation, and the concentrate after strong magnetic separation is pumped to the belt filter in the iron concentrate recovery process for filtration to obtain iron concentrate; the slag slurry after strong magnetic separation is sent to the thickener, and after gravity sedimentation and concentration by the thickener, the bottom slag is filtered through a ceramic filter to obtain tailings.

[0018] Furthermore, in the pellet coke recovery process, the slag fragments are subjected to two stages of wet magnetic separation, the first stage magnetic separation intensity is 3000-4000 Gs, and the second stage magnetic separation intensity is 5000-6000 Gs.

[0019] Furthermore, in the iron ore recovery process, the obtained coarse material is subjected to two stages of wet magnetic separation, the first stage magnetic separation intensity is 1600-2000 Gs, and the second stage magnetic separation intensity is 2200-2500 Gs.

[0020] Furthermore, in the carbon concentrate recovery process, the collector is kerosene and the foaming agent is 2# oil.

[0021] Furthermore, in the carbon concentrate recovery process, during the first roughing stage, the amount of kerosene used is 600-1000 g / t, and the amount of 2# oil used is 200-400 g / t.

[0022] Furthermore, in the silver concentrate recovery process, the collector is butyrate and the foaming agent is 2# oil.

[0023] Furthermore, in the silver concentrate recovery process, in the first roughing stage, the dosage of butyric acid xanthate is 400-600 g / t, and the dosage of 2# oil is 150-300 g / t; in the first scavenging stage, the dosage of butyric acid xanthate is 200-300 g / t, and the dosage of 2# oil is 75-150 g / t; in the second scavenging stage, the dosage of butyric acid xanthate is 100-150 g / t, and the dosage of 2# oil is 50-75 g / t.

[0024] Compared with the prior art, the present invention has at least the following beneficial effects:

[0025] The present invention provides a method for high-value comprehensive utilization of zinc smelting slag, which recycles the valuable elements in the slag produced by the volatilization kiln in the zinc smelting industry through a combined beneficiation method combining crushing, magnetic separation, gravity separation and flotation, and produces granular coke and carbon concentrate that can replace part of the volatilization kiln fuel, as well as iron concentrate and silver concentrate with high grade and economic value. It not only improves the recycling rate of resources, reduces the impact of solid waste storage and carbon emissions on the environment, but also further improves the economic value of the slag. Moreover, the process principle and process are relatively simple, belonging to a purely physical process, with low cost, low reaction requirements, energy saving and emission reduction, environmental friendliness, high economic benefits, good application prospects, and worthy of promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A flow chart of zinc smelting slag pretreatment and pelletized coke recovery processes in a method for high-value comprehensive utilization of zinc smelting slag provided in an embodiment of the present invention.

[0027] Figure 2 A flow chart of the comprehensive recovery process in a method for high-value comprehensive utilization of zinc smelting slag provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to better understand the above-mentioned technical scheme, the technical scheme of the embodiments of the present application is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present application and the specific features in the embodiments are detailed descriptions of the technical scheme of the embodiments of the present application, rather than limitations on the technical scheme of the present application. In the absence of conflict, the embodiments of the present application and the technical features in the embodiments may be combined with each other.

[0029] A first aspect of an embodiment of the present invention provides a method for high-value comprehensive utilization of zinc smelting slag, comprising the following steps:

[0030] Zinc smelting slag pretreatment: The zinc smelting slag is screened and crushed into slag fragments with a particle size of less than 2 cm for standby use;

[0031] Recovery of coke pellets: The crushed slag with a particle size of less than 2 cm is subjected to two-stage wet magnetic separation. The non-magnetic materials after magnetic separation are successively passed through a jig and a spiral classifier to screen out coke pellets. The magnetic materials after magnetic separation are used as raw materials for subsequent comprehensive recovery processes and are reserved for future use.

[0032] Iron concentrate recovery: the magnetic material after magnetic separation is passed through the wet first ball mill to obtain a coarse material with a grinding fineness of -200 mesh accounting for 35% to 45%; the obtained coarse material is passed through two stages of wet magnetic separation, and the magnetic concentrate after magnetic separation is filtered through a belt filter to obtain iron concentrate; the magnetic tailing material after magnetic separation is reserved;

[0033] Carbon concentrate recovery: The magnetic tailings after magnetic separation are passed through a wet second ball mill to obtain fine materials with a grinding fineness of -200 mesh accounting for 75% to 85%; the fine materials are subjected to a first coarse selection and a first fine selection in sequence, and a collector and a foaming agent are added to recover the carbon. The carbon concentrate obtained after fine selection is filtered with a ceramic filter to obtain carbon concentrate; the fine carbon concentrate tailings are reserved for later use;

[0034] Silver concentrate recovery: The selected carbon concentrate tailings are sequentially subjected to one-stage roughing, two-stage concentrating and two-stage scavenging, and silver is recovered by adding collectors and frothers. The slurry obtained after scavenging is filtered by a chamber filter to obtain silver concentrate; the silver concentrate tailings after scavenging are reserved for later use;

[0035] Tailings recovery: The silver concentrate tailings after scavenging are filtered through a ceramic filter to obtain tailings.

[0036] The method for high-value comprehensive utilization of zinc smelting kiln slag provided by the embodiment of the present invention recycles the valuable elements in the zinc smelting kiln slag through a combined beneficiation method combining crushing, magnetic separation, gravity separation and flotation, and adopts a purely physical process to produce granular coke and carbon concentrate that can replace part of the volatilization kiln fuel, as well as iron concentrate and silver concentrate with high grade and economic value. In addition, the tailings finally produced by the method for high-value comprehensive utilization of zinc smelting kiln slag provided by the embodiment of the present invention have a very low content of valuable elements and no longer have recycling value. They belong to general solid waste and can be used as raw materials for building materials without having a bad impact on the environment.

[0037] In some feasible implementations, in the pellet coke recovery process, the effluent from the jig and the spiral classifier enters the thickener, and after gravity sedimentation and concentration in the thickener, the bottom slag is controlled to obtain pellet coke again.

[0038] Through gravity sedimentation concentration of the thickener and water control of the bottom ash, the pelletized coke is further recovered, which further improves the recycling rate of resources and reduces pollution to the environment.

[0039] In some feasible implementations, in the iron concentrate recovery process, the magnetic concentrate after magnetic separation is filtered through a belt filter, and the resulting filtrate is sent to a chamber filter in the silver concentrate recovery process for filtration, and the silver concentrate is recovered together.

[0040] In the iron concentrate recovery process, the obtained coarse material is subjected to two-stage wet magnetic separation to produce high-silver iron magnetic concentrate containing ≥60wt% iron and >100g / t silver. After the magnetic concentrate is filtered after magnetic separation, some valuable metals iron and silver still remain in the filtrate, and the filtrate is reused to prevent waste of resources.

[0041] In some feasible implementations, the carbon concentrate recovery process also includes: first feeding the fine material with a grinding fineness of -200 mesh accounting for 75% to 85% into the hydrocyclone, and then performing a roughing selection and a fine selection on the slurry overflowing from the hydrocyclone in sequence; the sediment produced in the hydrocyclone is returned to the first ball mill.

[0042] The fine materials with a grinding fineness of -200 mesh, which accounts for 75% to 85%, first enter the hydrocyclone, which can quickly separate the ore particles by size. The fine materials with a size of about -200 mesh will overflow first and enter the flotation system. The sand in the hydrocyclone will return to the first ball mill, forming a closed circuit for non-magnetic material grinding, saving resources and preventing waste.

[0043] In some feasible implementations, the tailings recovery process includes: subjecting the scavenged silver concentrate tailings to strong magnetic separation, and the concentrate after strong magnetic separation is pumped to a belt filter in the iron concentrate recovery process for filtration to obtain iron concentrate; the slag slurry after strong magnetic separation is sent to a thickener, and after gravity sedimentation and concentration in the thickener, the bottom slag is filtered through a ceramic filter to obtain tailings.

[0044] The iron concentrate in the silver concentrate tailings can be further recovered through strong magnetic separation, which effectively increases the utilization rate of resources and effectively reduces the content of valuable elements in the tailings. It can be used as a raw material for building materials as general solid waste without having a negative impact on the environment.

[0045] In some feasible implementations, in the pellet coke recovery process, the slag fragments are subjected to two stages of wet magnetic separation, the first stage magnetic separation intensity is 3000-4000 Gs, and the second stage magnetic separation intensity is 5000-6000 Gs.

[0046] Magnetic separation intensity has a significant impact on magnetic separation. Although too low an intensity can increase the yield, the product quality is too low to meet the actual recycling needs. On the contrary, too high an intensity will reduce the yield. Both of these situations will result in a reduction in the recovery rate. In the pellet coke recovery process, after a large number of experiments, it was found that when the two-stage magnetic separation intensity is 3000-4000Gs and 5000-6000Gs respectively, the product quality and recovery rate can be effectively guaranteed.

[0047] In some feasible implementations, in the iron ore concentrate recovery process, the obtained coarse material is subjected to two stages of wet magnetic separation, the first stage magnetic separation intensity is 1600-2000 Gs, and the second stage magnetic separation intensity is 2200-2500 Gs.

[0048] Magnetic separation intensity has a significant impact on magnetic separation. Although too low an intensity can increase the yield, the product quality is too low to meet the actual recycling needs. On the contrary, too high an intensity will reduce the yield. Both of these situations will result in a reduction in recovery rate. In the recovery process of pellet coke, after a large number of experiments, it was found that when the two-stage magnetic separation intensity is 1600-2000Gs and 2200-2500Gs respectively, the product quality and recovery rate can be effectively guaranteed.

[0049] In some feasible implementations, in the carbon concentrate recovery process, the collector is kerosene and the foaming agent is 2# oil.

[0050] In the carbon concentrate recovery process, kerosene is used as the collector. Kerosene has good wettability, can increase the hydrophobicity of the mineral surface, promote the adsorption between mineral ions and bubbles, and improve the flotation effect. In addition, kerosene can form a bubble sedimentation film on the bubble surface, making the foam more stable, avoiding the deformation and rupture of the bubble, and increasing the contact between particles and bubbles. The foaming agent uses 2# oil, which has strong foaming properties and can produce a large number of uniform bubbles with appropriate viscosity.

[0051] Furthermore, in the carbon concentrate recovery process, during the first roughing stage, the amount of kerosene used is 600-1000 g / t, and the amount of 2# oil used is 200-400 g / t.

[0052] As the amount of reagent used for flotation carbon increases, the yield and recovery rate of carbon will increase accordingly, but as the amount of addition increases, the recovery rate gradually stabilizes and no longer has a significant increase, and the grade gradually decreases. Excessive addition does not continuously improve the recovery rate but increases the cost of reagents. After a large number of experiments, it was found that in the carbon concentrate recovery process, when the amount of kerosene is 600-1000g / t and the amount of 2# oil is 200-400g / t during the first roughing, carbon concentrate with a carbon grade of ≥60% can be obtained.

[0053] In some feasible implementations, in the silver concentrate recovery process, the collector is butyrate and the foaming agent is 2# oil.

[0054] In the silver concentrate recovery process, the collector uses butyl xanthate, which can selectively adsorb on the surface of the target mineral, promote its attachment to the bubbles, and strengthen separation. In addition, butyl xanthate also has certain foaming properties. The foaming agent uses 2# oil, which has strong foaming properties and can produce a large number of uniform bubbles with appropriate viscosity.

[0055] Furthermore, in the silver concentrate recovery process, in the first roughing stage, the dosage of butyric acid xanthate is 400-600 g / t, and the dosage of 2# oil is 150-300 g / t; in the first scavenging stage, the dosage of butyric acid xanthate is 200-300 g / t, and the dosage of 2# oil is 75-150 g / t; in the second scavenging stage, the dosage of butyric acid xanthate is 100-150 g / t, and the dosage of 2# oil is 50-75 g / t.

[0056] With the increase of the amount of silver flotation reagents used, the silver yield and recovery rate will increase accordingly, but with the increase of the dosage, the recovery rate gradually stabilizes and no longer has a significant increase and the grade gradually decreases. Excessive dosage cannot continuously improve the recovery rate but will increase the cost of reagents. After a large number of experiments, it was found that in the silver concentrate recovery process, in the first roughing selection, the dosage of butyl xanthate is 400-600g / t, and the dosage of 2# oil is 150-300g / t; in the first scavenging selection, the dosage of butyl xanthate is 200-300g / t, and the dosage of 2# oil is 75-150g / t; in the second scavenging selection, the dosage of butyl xanthate is 100-150g / t, and the dosage of 2# oil is 50-75g / t, and a silver concentrate with a silver grade of ≥100g / t can be obtained.

[0057] The method for high-value comprehensive utilization of zinc smelting kiln slag provided by the present invention has conducted research on the comprehensive recovery and utilization of carbon, silver, etc. from zinc smelting kiln slag, started from the process mineralogy research, systematically conducted mineral processing process test research and analysis, explored the optimal process parameters, and proposed a process flow for solving the problem of recycling carbon, silver and other elements from this type of zinc smelting kiln slag, providing a reference basis for the comprehensive utilization of secondary mineral resources, improving the environment, improving the production efficiency of enterprises and creating social benefits. At the same time, the method for high-value comprehensive utilization of zinc smelting kiln slag provided by the present invention has low requirements on the water quality of water used in the process of mineral processing, can be collected and reused, will not produce external drainage, will not cause a burden on zero discharge of industrial wastewater during actual application, and reduces the impact on the environment. The method for high-value comprehensive utilization of zinc smelting kiln slag provided by the present invention not only improves the recycling rate of resources, reduces the impact of solid waste storage and carbon emissions on the environment, but also further improves the economic value of kiln slag.

[0058] Example 1

[0059] See also Figure 1 and Figure 2 This embodiment provides a method for high-value comprehensive utilization of zinc smelting slag, comprising the following steps:

[0060] Step 1: Pretreatment of zinc smelting slag: The zinc smelting slag is screened and crushed into slag fragments with a particle size of less than 2 cm for standby use.

[0061] Preferably, in this embodiment, the zinc smelting slag is sequentially subjected to grating classification, first crushing, iron block removal by a belt remover, linear vibrating screen screening and second crushing to be crushed into slag fragments with a particle size of less than 2 cm for later use.

[0062] As an exemplary description, the specific examples are:

[0063] The raw zinc smelting slag is graded by a grating screen with an aperture of 150mm. The part below the grating screen enters the belt conveyor through the chute, and the part above the grating screen enters the first jaw crusher. The crushed slag enters the belt conveyor. A belt iron remover is hung above the belt conveyor to remove iron blocks. The slag without iron blocks is transported by the belt conveyor to the linear vibrating screen with an aperture of 20mm*20mm. The part of the slag above the screen enters the second jaw crusher and is crushed into fragments with a particle size of less than 2cm. The crushed slag and the part of the slag below the linear vibrating screen enter the belt conveyor and then enter the powder bin for standby use.

[0064] In order to prevent the generation of dust during the slag crushing process, it is washed with water while being graded with a grid screen. On the one hand, the slag is kept moist to prevent dust from being generated during crushing. On the other hand, the fine particles attached to the large particles of slag are washed off for better separation, preventing the iron blocks from taking away some fine particles of carbon and thus reducing the carbon recovery rate.

[0065] Step 2: Recovery of coke pellets: The crushed slag with a particle size of less than 2 cm is passed through two stages of wet magnetic separation. The non-magnetic materials after magnetic separation are successively passed through a jig and a spiral classifier to screen out coke pellets. The magnetic materials after magnetic separation enter the comprehensive recovery silo as raw materials for subsequent comprehensive recovery processes and are set aside.

[0066] Preferably, in this embodiment, the outlet water of the jig and the spiral classifier enters the thickener, and after being concentrated by gravity sedimentation in the thickener, the bottom residue is controlled to obtain pelletized coke again.

[0067] As an exemplary description, the specific examples are:

[0068] The crushed slag with a particle size less than 2 cm is subjected to two stages of wet magnetic separation. The first stage magnetic separation intensity is 3000Gs, and the second stage magnetic separation intensity is 5000Gs. The non-magnetic materials after the two stages of magnetic separation are successively screened out by jigs and spiral classifiers to obtain granular coke. The effluent from the jigs and spiral classifiers enters the first thickener. After gravity sedimentation and concentration in the first thickener, the bottom slag is controlled by water to obtain granular coke again, and the overflow of the first thickener enters the circulating water pool. The magnetic materials after magnetic separation enter the comprehensive recovery silo as raw materials for subsequent comprehensive recovery processes for standby use.

[0069] Step 3: Iron concentrate recovery: The magnetic material after magnetic separation is passed through the wet first ball mill to obtain a coarse material with a grinding fineness of -200 mesh accounting for 35%; the obtained coarse material is passed through two stages of wet magnetic separation, and the magnetic concentrate after magnetic separation is filtered through a belt filter to obtain iron concentrate; the magnetic tail material after magnetic separation is set aside;

[0070] Preferably, in this embodiment, the magnetic concentrate after magnetic separation is filtered through a belt filter, and the obtained filtrate is sent to a chamber filter in the silver concentrate recovery process for filtration, and the silver concentrate is recovered together.

[0071] As an exemplary description, the specific examples are:

[0072] The magnetic material in the comprehensive recovery silo is fed into the wet first ball mill by a disc feeder for ball milling to obtain a coarse material with a grinding fineness of -200 mesh accounting for 35%. After ball milling, the slurry is added with water and slurried into two stages of wet magnetic separation. The first stage magnetic separation intensity is 1600Gs, and the second stage magnetic separation intensity is 2200Gs. The magnetic concentrate (high silver iron concentrate slurry) after the two stages of magnetic separation is pumped to the belt vacuum filter for filtration to obtain iron concentrate. The filtrate obtained by filtration and the slurry after washing the filter cloth are pumped to the third thickener in the silver concentrate recovery process, and then filtered by a chamber filter to recover the silver concentrate together. The magnetic tailings after magnetic separation are set aside.

[0073] Step 4: Recovery of carbon concentrate: The magnetic tailings after magnetic separation are passed through a wet second ball mill to obtain fine material with a grinding fineness of -200 mesh accounting for 75%; the fine material is subjected to a first coarse selection and a first fine selection in sequence, and a collector and a frother are added to recover the carbon. The carbon concentrate obtained after fine selection is filtered with a ceramic filter to obtain carbon concentrate; the fine carbon concentrate tailings are set aside.

[0074] Preferably, in this embodiment, the fine material with a grinding fineness of -200 mesh accounting for 75% is first fed into the hydrocyclone, and then the slurry overflowing from the hydrocyclone is subjected to a roughing selection and a fine selection in sequence; the sediment produced in the hydrocyclone is returned to the first ball mill.

[0075] Preferably, in this embodiment, the collector is kerosene and the foaming agent is 2# oil.

[0076] Preferably, in this embodiment, during the first roughing step, the amount of kerosene used is 600 g / t, and the amount of 2# oil used is 200 g / t.

[0077] As an exemplary description, the specific examples are:

[0078] The magnetic tailings after magnetic separation are fed into the wet second ball mill for ball milling to obtain fine materials with a grinding fineness of -200 mesh accounting for 75%. The fine materials are pumped to the hydrocyclone. The overflow of the hydrocyclone enters the mixing barrel for slurry adjustment and then undergoes carbon flotation process, and then performs a roughing selection and a fine selection in sequence; in the roughing selection, the amount of kerosene is 600g / t, and the amount of 2# oil is 200g / t. The carbon is recovered, and the carbon concentrate obtained after fine selection is pumped to the second thickener. After gravity sedimentation and concentration in the second thickener, the bottom slag is pumped to the buffer mixing barrel, and after slurry adjustment, it is filtered with a ceramic filter to obtain carbon concentrate. The overflow of the second thickener enters the circulating water pool. The fine carbon tailings after fine selection are used for standby. The sediment produced in the hydrocyclone is returned to the first ball mill to form a closed circuit for non-magnetic material grinding.

[0079] Step 5: Recovery of silver concentrate: The selected carbon concentrate tailings are sequentially passed through a roughing stage, two concentration stages and two scavenging stages, and collectors and frothers are added to recover the silver. The slurry obtained after scavenging is filtered with a chamber filter to obtain silver concentrate; the silver concentrate tailings after scavenging are kept for later use.

[0080] Preferably, in this embodiment, the collector is xanthate and the foaming agent is 2# oil.

[0081] Preferably, in this embodiment, in the first roughing stage, the dosage of butyric acid is 400g / t, and the dosage of 2# oil is 200g / t; in the first scavenging stage, the dosage of butyric acid is 200g / t, and the dosage of 2# oil is 100g / t; in the second scavenging stage, the dosage of butyric acid is 100g / t, and the dosage of 2# oil is 50g / t.

[0082] As an exemplary description, the specific examples are:

[0083] The carbon concentrate tailings after scavenging are lifted into the mixing barrel, and the silver flotation process is carried out after slurry adjustment. It goes through one roughing, two fine selections and two scavenging in sequence. In the first roughing, the dosage of butyric acid is 400g / t, and the dosage of 2# oil is 200g / t; in the first scavenging, the dosage of butyric acid is 200g / t, and the dosage of 2# oil is 100g / t; in the second scavenging, the dosage of butyric acid is 100g / t, and the dosage of 2# oil is 50g / t. The slurry obtained after scavenging is pumped to the third thickener. After gravity sedimentation and concentration in the third thickener, the bottom slag is pumped to the buffer mixing barrel, and after slurry adjustment, it is transported to the chamber filter by the filter press pump for filtration to obtain silver concentrate. The overflow of the third thickener enters the circulating water pool. The silver concentrate tailings after scavenging are reserved.

[0084] Step 6: Tailings recovery: The silver concentrate tailings after scavenging are filtered through a ceramic filter to obtain tailings.

[0085] Preferably, in this embodiment, the silver concentrate tailings after scavenging are subjected to strong magnetic separation, and the concentrate after strong magnetic separation is transported by a pump to a belt filter in the iron concentrate recovery process for filtration to obtain iron concentrate; the slag slurry after strong magnetic separation is sent to a thickener, and after gravity sedimentation and concentration in the thickener, the bottom slag is filtered through a ceramic filter to obtain tailings.

[0086] As an exemplary description, the specific examples are:

[0087] The silver concentrate tailings after scavenging are subjected to strong magnetic separation. The concentrate after strong magnetic separation is pumped to the belt vacuum filter in the iron concentrate recovery process for filtration to obtain iron concentrate; the slurry after strong magnetic separation is pumped to the fourth thickener by the slurry pump. After gravity sedimentation and concentration in the thickener, the bottom slag is pumped to the buffer mixing tank, and after slurry adjustment, it is filtered in the ceramic filter to obtain tailings. The overflow of the fourth thickener enters the circulating water pool.

[0088] Example 2

[0089] See also Figure 1 and Figure 2 This embodiment provides a method for high-value comprehensive utilization of zinc smelting slag, comprising the following steps:

[0090] Step 1: Pretreatment of zinc smelting slag: The zinc smelting slag is screened and crushed into slag fragments with a particle size of less than 2 cm for standby use.

[0091] Preferably, in this embodiment, the zinc smelting slag is sequentially subjected to grating classification, first crushing, iron block removal by a belt remover, linear vibrating screen screening and second crushing to be crushed into slag fragments with a particle size of less than 2 cm for later use.

[0092] As an exemplary description, the specific examples are:

[0093] The raw zinc smelting slag is graded by a grating screen with an aperture of 150mm. The part below the grating screen enters the belt conveyor through the chute, and the part above the grating screen enters the first jaw crusher. The crushed slag enters the belt conveyor. A belt iron remover is hung above the belt conveyor to remove iron blocks. The slag without iron blocks is transported by the belt conveyor to the linear vibrating screen with an aperture of 20mm*20mm. The part of the slag above the screen enters the second jaw crusher and is crushed into fragments with a particle size of less than 2cm. The crushed slag and the part of the slag below the linear vibrating screen enter the belt conveyor and then enter the powder bin for standby use.

[0094] In order to prevent the generation of dust during the slag crushing process, it is washed with water while being graded with a grid screen. On the one hand, the slag is kept moist to prevent dust from being generated during crushing. On the other hand, the fine particles attached to the large particles of slag are washed off for better separation, preventing the iron blocks from taking away some fine particles of carbon and thus reducing the carbon recovery rate.

[0095] Step 2: Recovery of coke pellets: The crushed slag with a particle size of less than 2 cm is passed through two stages of wet magnetic separation. The non-magnetic materials after magnetic separation are successively passed through a jig and a spiral classifier to screen out coke pellets. The magnetic materials after magnetic separation enter the comprehensive recovery silo as raw materials for subsequent comprehensive recovery processes and are set aside.

[0096] Preferably, in this embodiment, the outlet water of the jig and the spiral classifier enters the thickener, and after being concentrated by gravity sedimentation in the thickener, the bottom residue is controlled to obtain pelletized coke again.

[0097] As an exemplary description, the specific examples are:

[0098] The crushed slag with a particle size less than 2 cm is subjected to two stages of wet magnetic separation. The first stage magnetic separation intensity is 3500Gs, and the second stage magnetic separation intensity is 5500Gs. The non-magnetic materials after the two stages of magnetic separation are successively screened out by jigs and spiral classifiers to obtain granular coke. The effluent from the jigs and spiral classifiers enters the first thickener. After gravity sedimentation and concentration in the first thickener, the bottom slag is controlled by water to obtain granular coke again, and the overflow of the first thickener enters the circulating water pool. The magnetic materials after magnetic separation enter the comprehensive recovery silo as raw materials for subsequent comprehensive recovery processes for standby use.

[0099] Step 3: Iron concentrate recovery: The magnetic material after magnetic separation is passed through the wet first ball mill to obtain a coarse material with a grinding fineness of -200 mesh accounting for 40%; the obtained coarse material is passed through two stages of wet magnetic separation, and the magnetic concentrate after magnetic separation is filtered through a belt filter to obtain iron concentrate; the magnetic tail material after magnetic separation is set aside;

[0100] Preferably, in this embodiment, the magnetic concentrate after magnetic separation is filtered through a belt filter, and the obtained filtrate is sent to a chamber filter in the silver concentrate recovery process for filtration, and the silver concentrate is recovered together.

[0101] As an exemplary description, the specific examples are:

[0102] The magnetic material in the comprehensive recovery silo is fed into the wet first ball mill by a disc feeder for ball milling to obtain a coarse material with a grinding fineness of -200 mesh accounting for 40%. After ball milling, the slurry is added with water and slurried into two stages of wet magnetic separation. The first stage magnetic separation intensity is 1800Gs, and the second stage magnetic separation intensity is 2300Gs. The magnetic concentrate (high silver iron concentrate slurry) after the two stages of magnetic separation is pumped to the belt vacuum filter for filtration to obtain iron concentrate. The filtrate obtained by filtration and the slurry after washing the filter cloth are pumped to the chamber filter in the silver concentrate recovery process for filtration, and the silver concentrate is recovered together. The magnetic tailings after magnetic separation are set aside.

[0103] Step 4: Recovery of carbon concentrate: The magnetic tail material after magnetic separation is passed through a wet second ball mill to obtain fine material with a grinding fineness of -200 mesh accounting for 80%; the fine material is subjected to a first coarse selection and a first fine selection in sequence, and a collector and a frother are added to recover the carbon. The carbon concentrate obtained after fine selection is filtered with a ceramic filter to obtain carbon concentrate; the fine carbon concentrate tailings are set aside.

[0104] Preferably, in this embodiment, the fine material with a grinding fineness of -200 mesh accounting for 80% is first fed into the hydrocyclone, and then the slurry overflowing from the hydrocyclone is subjected to a roughing selection and a fine selection in sequence; the sediment produced in the hydrocyclone is returned to the first ball mill.

[0105] Preferably, in this embodiment, the collector is kerosene and the foaming agent is 2# oil.

[0106] Preferably, in this embodiment, during the first roughing step, the amount of kerosene used is 800 g / t, and the amount of 2# oil used is 300 g / t.

[0107] As an exemplary description, the specific examples are:

[0108] The magnetic tailings after magnetic separation are fed into the wet second ball mill for ball milling to obtain fine materials with a grinding fineness of -200 mesh accounting for 80%. The fine materials are pumped to the hydrocyclone. The overflow of the hydrocyclone enters the mixing barrel for slurry adjustment and then undergoes carbon flotation process, and then performs a roughing selection and a fine selection in sequence; in the roughing selection, the amount of kerosene is 800g / t, and the amount of 2# oil is 300g / t. The carbon is recovered, and the carbon concentrate obtained after fine selection is pumped to the second thickener. After gravity sedimentation and concentration in the second thickener, the bottom slag is pumped to the buffer mixing barrel, and after slurry adjustment, it is filtered with a ceramic filter to obtain carbon concentrate. The overflow of the second thickener enters the circulating water pool. The fine carbon tailings after fine selection are used for standby. The sediment produced in the hydrocyclone is returned to the first ball mill to form a closed circuit for non-magnetic material grinding.

[0109] Step 5: Recovery of silver concentrate: The selected carbon concentrate tailings are sequentially passed through a roughing stage, two concentration stages and two scavenging stages, and collectors and frothers are added to recover the silver. The slurry obtained after scavenging is filtered with a chamber filter to obtain silver concentrate; the silver concentrate tailings after scavenging are kept for later use.

[0110] Preferably, in this embodiment, the collector is xanthate and the foaming agent is 2# oil.

[0111] Preferably, in this embodiment, in the first roughing stage, the dosage of butyric acid is 500 g / t, and the dosage of 2# oil is 200 g / t; in the first scavenging stage, the dosage of butyric acid is 250 g / t, and the dosage of 2# oil is 100 g / t; in the second scavenging stage, the dosage of butyric acid is 125 g / t, and the dosage of 2# oil is 50 g / t.

[0112] As an exemplary description, the specific examples are:

[0113] The carbon concentrate tailings after scavenging are put into the lifting and stirring barrel, and the silver flotation process is carried out after slurry adjustment. It goes through one roughing, two fine selections and two scavenging in sequence. In the first roughing, the dosage of butyric acid is 500g / t, and the dosage of 2# oil is 200g / t; in the first scavenging, the dosage of butyric acid is 250g / t, and the dosage of 2# oil is 100g / t; in the second scavenging, the dosage of butyric acid is 125g / t, and the dosage of 2# oil is 50g / t. The slurry obtained after scavenging is pumped to the third thickener. After gravity sedimentation and concentration in the third thickener, the bottom slag is pumped to the buffer stirring barrel, and after slurry adjustment, it is transported to the chamber filter by the filter press pump for filtration to obtain silver concentrate. The overflow of the third thickener enters the circulating water pool. The silver concentrate tailings after scavenging are reserved.

[0114] Step 6: Tailings recovery: The silver concentrate tailings after scavenging are filtered through a ceramic filter to obtain tailings.

[0115] Preferably, in this embodiment, the silver concentrate tailings after scavenging are subjected to strong magnetic separation, and the concentrate after strong magnetic separation is transported by a pump to a belt filter in the iron concentrate recovery process for filtration to obtain iron concentrate; the slag slurry after strong magnetic separation is sent to a thickener, and after gravity sedimentation and concentration in the thickener, the bottom slag is filtered through a ceramic filter to obtain tailings.

[0116] As an exemplary description, the specific examples are:

[0117] The silver concentrate tailings after scavenging are subjected to strong magnetic separation. The concentrate after strong magnetic separation is pumped to the belt vacuum filter in the iron concentrate recovery process for filtration to obtain iron concentrate; the slurry after strong magnetic separation is pumped to the fourth thickener by the slurry pump. After gravity sedimentation and concentration in the thickener, the bottom slag is pumped to the buffer mixing tank, and after slurry adjustment, it is filtered in the ceramic filter to obtain tailings. The overflow of the fourth thickener enters the circulating water pool.

[0118] Example 3

[0119] See also Figure 1 and Figure 2 This embodiment provides a method for high-value comprehensive utilization of zinc smelting slag, comprising the following steps:

[0120] Step 1: Pretreatment of zinc smelting slag: The zinc smelting slag is screened and crushed into slag fragments with a particle size of less than 2 cm for standby use.

[0121] Preferably, in this embodiment, the zinc smelting slag is sequentially subjected to grating classification, first crushing, iron block removal by a belt remover, linear vibrating screen screening and second crushing to be crushed into slag fragments with a particle size of less than 2 cm for later use.

[0122] As an exemplary description, the specific examples are:

[0123] The raw zinc smelting slag is graded by a grating screen with an aperture of 150mm. The part below the grating screen enters the belt conveyor through the chute, and the part above the grating screen enters the first jaw crusher. The crushed slag enters the belt conveyor. A belt iron remover is hung above the belt conveyor to remove iron blocks. The slag without iron blocks is transported by the belt conveyor to the linear vibrating screen with an aperture of 20mm*20mm. The part of the slag above the screen enters the second jaw crusher and is crushed into fragments with a particle size of less than 2cm. The crushed slag and the part of the slag below the linear vibrating screen enter the belt conveyor and then enter the powder bin for standby use.

[0124] In order to prevent the generation of dust during the slag crushing process, it is washed with water while being graded with a grid screen. On the one hand, the slag is kept moist to prevent dust from being generated during crushing. On the other hand, the fine particles attached to the large particles of slag are washed off for better separation, preventing the iron blocks from taking away some fine particles of carbon and thus reducing the carbon recovery rate.

[0125] Step 2: Recovery of coke pellets: The crushed slag with a particle size of less than 2 cm is passed through two stages of wet magnetic separation. The non-magnetic materials after magnetic separation are successively passed through a jig and a spiral classifier to screen out coke pellets. The magnetic materials after magnetic separation enter the comprehensive recovery silo as raw materials for subsequent comprehensive recovery processes and are set aside.

[0126] Preferably, in this embodiment, the outlet water of the jig and the spiral classifier enters the thickener, and after being concentrated by gravity sedimentation in the thickener, the bottom residue is controlled to obtain pelletized coke again.

[0127] As an exemplary description, the specific examples are:

[0128] The crushed kiln slag with a particle size less than 2cm is subjected to two stages of wet magnetic separation. The first stage magnetic separation intensity is 4000Gs, and the second stage magnetic separation intensity is 6000Gs. The non-magnetic materials after the two stages of magnetic separation are successively screened out by jigs and spiral classifiers to obtain granular coke. The effluent from the jigs and spiral classifiers enters the first thickener. After gravity sedimentation and concentration in the first thickener, the bottom slag is controlled by water to obtain granular coke again, and the overflow of the first thickener enters the circulating water pool. The magnetic materials after magnetic separation enter the comprehensive recovery silo as raw materials for subsequent comprehensive recovery processes for standby use.

[0129] Step 3: Iron concentrate recovery: The magnetic material after magnetic separation is passed through the wet first ball mill to obtain a coarse material with a grinding fineness of -200 mesh accounting for 45%; the obtained coarse material is passed through two stages of wet magnetic separation, and the magnetic concentrate after magnetic separation is filtered through a belt filter to obtain iron concentrate; the magnetic tail material after magnetic separation is set aside;

[0130] Preferably, in this embodiment, the magnetic concentrate after magnetic separation is filtered through a belt filter, and the obtained filtrate is sent to a chamber filter in the silver concentrate recovery process for filtration, and the silver concentrate is recovered together.

[0131] As an exemplary description, the specific examples are:

[0132] The magnetic material in the comprehensive recovery silo is fed into the wet first ball mill by a disc feeder for ball milling to obtain a coarse material with a grinding fineness of -200 mesh accounting for 45%. After ball milling, the slurry is mixed with water and enters two stages of wet magnetic separation. The first stage magnetic separation intensity is 2000Gs, and the second stage magnetic separation intensity is 2500Gs. The magnetic concentrate (high silver iron concentrate slurry) after two stages of magnetic separation is pumped to a belt vacuum filter for filtration to obtain iron concentrate. The filtrate obtained by filtration and the slurry after washing the filter cloth are pumped to the chamber filter in the silver concentrate recovery process for filtration, and the silver concentrate is recovered together. The magnetic tailings after magnetic separation are set aside.

[0133] Step 4: Recovery of carbon concentrate: The magnetic tail material after magnetic separation is passed through a wet second ball mill to obtain fine material with a grinding fineness of -200 mesh accounting for 85%; the fine material is subjected to a first coarse selection and a first fine selection in sequence, and a collector and a frother are added to recover the carbon. The carbon concentrate obtained after fine selection is filtered with a ceramic filter to obtain carbon concentrate; the fine carbon concentrate tailings are set aside.

[0134] Preferably, in this embodiment, the fine material with a grinding fineness of -200 mesh accounting for 85% is first fed into the hydrocyclone, and then the slurry overflowing from the hydrocyclone is subjected to a roughing selection and a fine selection in sequence; the sediment produced in the hydrocyclone is returned to the first ball mill.

[0135] Preferably, in this embodiment, the collector is kerosene and the foaming agent is 2# oil.

[0136] Preferably, in this embodiment, during the first roughing step, the amount of kerosene used is 1000 g / t, and the amount of 2# oil used is 400 g / t.

[0137] As an exemplary description, the specific examples are:

[0138] The magnetic tailings after magnetic separation are fed into the wet second ball mill for ball milling to obtain fine materials with a grinding fineness of -200 mesh accounting for 85%. The fine materials are pumped to the hydrocyclone. The overflow of the hydrocyclone enters the mixing barrel for slurry adjustment and then undergoes carbon flotation process, and then performs a roughing selection and a fine selection in sequence; in the roughing selection, the amount of kerosene is 1000g / t, and the amount of 2# oil is 400g / t. The carbon is recovered, and the carbon concentrate obtained after fine selection is pumped to the second thickener. After gravity sedimentation and concentration in the second thickener, the bottom slag is pumped to the buffer mixing barrel, and after slurry adjustment, it is filtered with a ceramic filter to obtain carbon concentrate. The overflow of the second thickener enters the circulating water pool. The fine carbon tailings after fine selection are used for standby. The sediment produced in the hydrocyclone is returned to the first ball mill to form a closed circuit for non-magnetic material grinding.

[0139] Step 5: Recovery of silver concentrate: The selected carbon concentrate tailings are sequentially passed through a roughing stage, two concentration stages and two scavenging stages, and collectors and frothers are added to recover the silver. The slurry obtained after scavenging is filtered with a chamber filter to obtain silver concentrate; the silver concentrate tailings after scavenging are kept for later use.

[0140] Preferably, in this embodiment, the collector is xanthate and the foaming agent is 2# oil.

[0141] Preferably, in this embodiment, in the first roughing stage, the dosage of butyric acid is 600g / t, and the dosage of 2# oil is 300g / t; in the first scavenging stage, the dosage of butyric acid is 300g / t, and the dosage of 2# oil is 150g / t; in the second scavenging stage, the dosage of butyric acid is 150g / t, and the dosage of 2# oil is 75g / t.

[0142] As an exemplary description, the specific examples are:

[0143] The carbon concentrate tailings after scavenging are put into the lifting and stirring barrel, and the silver flotation process is carried out after slurry adjustment. It goes through one roughing, two fine selections and two scavenging in sequence. In the first roughing, the dosage of butyric acid is 600g / t, and the dosage of 2# oil is 300g / t; in the first scavenging, the dosage of butyric acid is 300g / t, and the dosage of 2# oil is 150g / t; in the second scavenging, the dosage of butyric acid is 150g / t, and the dosage of 2# oil is 75g / t. The slurry obtained after scavenging is pumped to the third thickener. After gravity sedimentation and concentration in the third thickener, the bottom slag is pumped to the buffer stirring barrel, and after slurry adjustment, it is transported to the chamber filter by the filter press pump for filtration to obtain silver concentrate. The overflow of the third thickener enters the circulating water pool. The silver concentrate tailings after scavenging are reserved.

[0144] Step 6: Tailings recovery: The silver concentrate tailings after scavenging are filtered through a ceramic filter to obtain tailings.

[0145] Preferably, in this embodiment, the silver concentrate tailings after scavenging are subjected to strong magnetic separation, and the concentrate after strong magnetic separation is transported by a pump to a belt filter in the iron concentrate recovery process for filtration to obtain iron concentrate; the slag slurry after strong magnetic separation is sent to a thickener, and after gravity sedimentation and concentration in the thickener, the bottom slag is filtered through a ceramic filter to obtain tailings.

[0146] As an exemplary description, the specific examples are:

[0147] The silver concentrate tailings after scavenging are subjected to strong magnetic separation. The concentrate after strong magnetic separation is pumped to the belt vacuum filter in the iron concentrate recovery process for filtration to obtain iron concentrate; the slurry after strong magnetic separation is pumped to the fourth thickener by the slurry pump. After gravity sedimentation and concentration in the thickener, the bottom slag is pumped to the buffer mixing tank, and after slurry adjustment, it is filtered in the ceramic filter to obtain tailings. The overflow of the fourth thickener enters the circulating water pool.

[0148] Comparative Example 1

[0149] See also Figure 1 and Figure 2 This embodiment provides a method for high-value comprehensive utilization of zinc smelting slag, comprising the following steps:

[0150] Step 1: Pretreatment of zinc smelting slag: The raw zinc smelting slag is graded by a sieve with an aperture of 150mm. The part below the sieve enters the belt conveyor through the chute, and the part above the sieve enters the first jaw crusher. The slag after crushing enters the belt conveyor. A belt iron remover is hung above the belt conveyor to remove iron blocks. The slag without iron blocks is transported by the belt conveyor to the linear vibrating screen with an aperture of 20mm*20mm. The part of the slag above the screen enters the second jaw crusher and is crushed into fragments with a particle size of less than 2cm. The crushed slag and the part of the slag below the linear vibrating screen enter the belt conveyor and then enter the powder bin for standby use.

[0151] In order to prevent the generation of dust during the slag crushing process, it is washed with water while being graded with a grid screen. On the one hand, the slag is kept moist to prevent dust from being generated during crushing. On the other hand, the fine particles attached to the large particles of slag are washed off for better separation, preventing the iron blocks from taking away some fine particles of carbon and thus reducing the carbon recovery rate.

[0152] Step 2: Recovery of coke pellets: The crushed slag with a particle size of less than 2 cm is subjected to two stages of wet magnetic separation. The first stage magnetic separation intensity is 1000Gs, and the second stage magnetic separation intensity is 2000Gs. The non-magnetic materials after the two stages of magnetic separation are successively screened out by a jig and a spiral classifier to obtain coke pellets. The effluent from the jig and spiral classifier enters the first thickener. After gravity sedimentation and concentration by the first thickener, the bottom slag is controlled by water to obtain coke pellets again. The overflow of the first thickener enters the circulating water pool. The magnetic materials after magnetic separation enter the comprehensive recovery silo as raw materials for subsequent comprehensive recovery processes for standby use.

[0153] Step 3: Iron concentrate recovery: The magnetic material in the comprehensive recovery silo is fed into the wet first ball mill by a disc feeder for ball milling to obtain a coarse material with a grinding fineness of -200 mesh accounting for 45%. After ball milling, the slurry is added with water and slurried into two stages of wet magnetic separation. The first stage magnetic separation intensity is 1500Gs, and the second stage magnetic separation intensity is 2000Gs. The magnetic concentrate (high silver iron concentrate slurry) after the two stages of magnetic separation is pumped to a belt vacuum filter for filtration to obtain iron concentrate. The filtrate obtained by filtration and the slurry after washing the filter cloth are pumped to the chamber filter in the silver concentrate recovery process for filtration, and the silver concentrate is recovered together. The magnetic tail material after magnetic separation is set aside.

[0154] Step 4: Carbon concentrate recovery: The magnetic tailings after magnetic separation are fed into the wet second ball mill for ball milling to obtain fine materials with a grinding fineness of -200 mesh accounting for 85%. The fine materials are pumped to the hydrocyclone. The overflow of the hydrocyclone enters the mixing barrel for slurry adjustment and then undergoes carbon flotation process, and then performs a roughing selection and a fine selection in sequence; in the roughing selection, the amount of kerosene is 400g / t, and the amount of 2# oil is 200g / t. The carbon is recovered, and the carbon concentrate obtained after fine selection is pumped to the second thickener. After gravity sedimentation and concentration in the second thickener, the bottom slag is pumped to the buffer stirring barrel, and after slurry adjustment, it is filtered with a ceramic filter to obtain carbon concentrate. The overflow of the second thickener enters the circulating water pool. The fine carbon tailings after fine selection are reserved. The sediment produced in the hydrocyclone is returned to the first ball mill to form a closed circuit for non-magnetic material grinding.

[0155] Step 5: Recovery of silver concentrate: The carbon concentrate tailings after scavenging are put into the lifting and stirring barrel for slurry adjustment and then silver flotation process is carried out. It goes through one roughing, two fine selections and two scavenging in sequence. In the first roughing, the dosage of butyric acid is 400g / t and the dosage of 2# oil is 200g / t; in the first scavenging, the dosage of butyric acid is 200g / t and the dosage of 2# oil is 100g / t; in the second scavenging, the dosage of butyric acid is 100g / t and the dosage of 2# oil is 50g / t. The slurry obtained after scavenging is pumped to the third thickener. After gravity sedimentation and concentration of the third thickener, the bottom slag is pumped to the buffer stirring barrel. After slurry adjustment, it is pumped to the chamber filter by the filter press pump to obtain silver concentrate. The overflow of the third thickener enters the circulating water pool. The silver concentrate tailings after scavenging are reserved.

[0156] Step 6: Tailings recovery: The silver concentrate tailings after scavenging are subjected to strong magnetic separation. The concentrate after strong magnetic separation is pumped to the belt vacuum filter in the iron concentrate recovery process for filtration to obtain iron concentrate; the slurry after strong magnetic separation is pumped to the fourth thickener by the slurry pump. After gravity sedimentation and concentration in the thickener, the bottom slag is pumped to the buffer mixing tank, and after slurry adjustment, it is filtered in the ceramic filter to obtain tailings. The overflow of the fourth thickener enters the circulating water pool.

[0157] Comparative Example 2

[0158] See also Figure 1 and Figure 2 This embodiment provides a method for high-value comprehensive utilization of zinc smelting slag, comprising the following steps:

[0159] Step 1: Pretreatment of zinc smelting slag: The raw zinc smelting slag is graded by a sieve with an aperture of 150mm. The part below the sieve enters the belt conveyor through the chute, and the part above the sieve enters the first jaw crusher. The slag after crushing enters the belt conveyor. A belt iron remover is hung above the belt conveyor to remove iron blocks. The slag without iron blocks is transported by the belt conveyor to the linear vibrating screen with an aperture of 20mm*20mm. The part of the slag above the screen enters the second jaw crusher and is crushed into fragments with a particle size of less than 2cm. The crushed slag and the part of the slag below the linear vibrating screen enter the belt conveyor and then enter the powder bin for standby use.

[0160] In order to prevent the generation of dust during the slag crushing process, it is washed with water while being graded with a grid screen. On the one hand, the slag is kept moist to prevent dust from being generated during crushing. On the other hand, the fine particles attached to the large particles of slag are washed off for better separation, preventing the iron blocks from taking away some fine particles of carbon and thus reducing the carbon recovery rate.

[0161] Step 2: Recovery of coke pellets: The crushed slag with a particle size of less than 2 cm is subjected to two stages of wet magnetic separation. The first stage magnetic separation intensity is 5000Gs, and the second stage magnetic separation intensity is 7500Gs. The non-magnetic materials after the two stages of magnetic separation are successively screened out by jigs and spiral classifiers to obtain coke pellets. The effluent from the jigs and spiral classifiers enters the first thickener. After gravity sedimentation and concentration by the first thickener, the bottom slag is controlled by water to obtain coke pellets again. The overflow of the first thickener enters the circulating water pool. The magnetic materials after magnetic separation enter the comprehensive recovery silo as raw materials for subsequent comprehensive recovery processes for standby use.

[0162] Step 3: Iron concentrate recovery: The magnetic material in the comprehensive recovery silo is fed into the wet first ball mill by a disc feeder for ball milling to obtain a coarse material with a grinding fineness of -200 mesh accounting for 50%. After ball milling, the slurry is added with water and slurried into two stages of wet magnetic separation. The first stage magnetic separation intensity is 2500Gs, and the second stage magnetic separation intensity is 3500Gs. The magnetic concentrate (high silver iron concentrate slurry) after the two stages of magnetic separation is pumped to the belt vacuum filter for filtration to obtain iron concentrate. The filtrate obtained by filtration and the slurry after washing the filter cloth are pumped to the chamber filter in the silver concentrate recovery process for filtration, and the silver concentrate is recovered together. The magnetic tail material after magnetic separation is set aside.

[0163] Step 4: Carbon concentrate recovery: The magnetic tailings after magnetic separation are fed into the wet second ball mill for ball milling to obtain fine materials with a grinding fineness of -200 mesh accounting for 80%. The fine materials are pumped to the hydrocyclone. The overflow of the hydrocyclone enters the mixing barrel for slurry adjustment and then undergoes carbon flotation process, and then performs a roughing selection and a fine selection in sequence; in the roughing selection, the amount of kerosene is 1000g / t, and the amount of 2# oil is 300g / t. The carbon is recovered, and the carbon concentrate obtained after fine selection is pumped to the second thickener. After gravity sedimentation and concentration in the second thickener, the bottom slag is pumped to the buffer stirring barrel, and after slurry adjustment, it is filtered with a ceramic filter to obtain carbon concentrate. The overflow of the second thickener enters the circulating water pool. The fine carbon tailings after fine selection are reserved. The sediment produced in the hydrocyclone is returned to the first ball mill to form a closed circuit for non-magnetic material grinding.

[0164] Step 5: Recovery of silver concentrate: The selected carbon concentrate tailings are put into the lifting and stirring barrel for slurry adjustment and then silver flotation process is carried out. It goes through one roughing, two concentrating and two scavenging stages in sequence. In the first roughing stage, the dosage of butyric acid is 600g / t and the dosage of 2# oil is 200g / t; in the first scavenging stage, the dosage of butyric acid is 300g / t and the dosage of 2# oil is 100g / t; in the second scavenging stage, the dosage of butyric acid is 150g / t and the dosage of 2# oil is 50g / t. The slurry obtained after scavenging is pumped to the third thickener by a pump. After gravity sedimentation and concentration by the third thickener, the bottom slag is pumped to the buffer stirring barrel by a pump. After slurry adjustment, it is transported to the chamber filter by a filter press pump for filtration to obtain silver concentrate. The overflow of the third thickener enters the circulating water pool. The silver concentrate tailings after scavenging are set aside.

[0165] Step 6: Tailings recovery: The silver concentrate tailings after scavenging are filtered through a ceramic filter to obtain tailings.

[0166] Preferably, in this embodiment, the silver concentrate tailings after scavenging are subjected to strong magnetic separation, and the concentrate after strong magnetic separation is transported by a pump to a belt filter in the iron concentrate recovery process for filtration to obtain iron concentrate; the slag slurry after strong magnetic separation is sent to a thickener, and after gravity sedimentation and concentration in the thickener, the bottom slag is filtered through a ceramic filter to obtain tailings.

[0167] As an exemplary description, the specific examples are:

[0168] The silver concentrate tailings after scavenging are subjected to strong magnetic separation. The concentrate after strong magnetic separation is pumped to the belt vacuum filter in the iron concentrate recovery process for filtration to obtain iron concentrate; the slurry after strong magnetic separation is pumped to the fourth thickener by the slurry pump. After gravity sedimentation and concentration in the thickener, the bottom slag is pumped to the buffer mixing tank, and after slurry adjustment, it is filtered in the ceramic filter to obtain tailings. The overflow of the fourth thickener enters the circulating water pool.

[0169] Example 4: Application

[0170] In this embodiment, the slag from the zinc smelting volatilization kiln of Zhuzhou Nonferrous Zinc Oxide Plant was selected as the experimental ore. The mineral composition elements of the zinc smelting slag of the experimental ore are shown in Table 1.

[0171] Table 1 Elemental analysis of raw materials (%)

[0172] project TFe MFe Ag* Au* S carbon content 30.07 16.94 58.12 0.14 4.88 29.19 project Zn Pb Cu <![CDATA[SiO2]]> CaO <![CDATA[Al2O3]]> content 1.52 0.54 0.58 6.66 4.39 5.82

[0173] The experimental ore was beneficiated by the experimental methods of Examples 1, 2, 3 and Comparative Examples 1 and 2 to recover carbon and valuable metals therein. The results are shown in Table 2.

[0174] Table 2

[0175]

[0176]

[0177] From the data in Table 2, it can be seen that the magnetic separation intensity, grinding fineness and reagent usage of slag beneficiation directly affect the yield and grade of the product (Experimental Examples 1, 2, 3 and Comparative Examples 1, 2). Although too low magnetic separation intensity can improve the yield, the product grade is low and cannot meet the actual reuse demand. On the contrary, too high magnetic separation intensity will reduce the yield. Both of these situations will cause a decrease in the recovery rate, which shows that moderate control of magnetic separation intensity can effectively ensure the grade and recovery rate of the product; and when selecting iron, although the fineness of grinding has little effect on the overall recovery rate, it has a certain effect on the enrichment degree of silver (Experimental Examples 1, 2, 3 and Comparative Example 2). When the grinding fineness -200 mesh is controlled at 35% to 45%, the silver content in the iron concentrate is >100g / t, which is lower than 35%. Or if it is higher than 45%, it is <100g / t. According to the current pricing method for iron concentrate in the market, the silver content in the iron concentrate is not included in the pricing range when it is <100g / t, which will cause a significant drop in the economic value of the product. Therefore, the grinding fineness of iron selection must be strictly controlled; the higher the grinding fineness of carbon and silver selection, the higher the yield of carbon concentrate and silver concentrate and the recovery rate of carbon and silver in the selection (Experimental Examples 1, 2, 3); in addition, with the increase in the amount of flotation carbon and silver reagents used, the yield and recovery rate of carbon and silver will increase accordingly, but with the increase in the amount of addition, the recovery rate gradually stabilizes and no longer has a significant increase and the grade gradually decreases (Experimental Examples 1, 2, 3), so excessive addition cannot continuously improve the recovery rate but will increase the reagent cost.

[0178] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A method for high-value comprehensive utilization of zinc smelting slag, characterized in that: include: Zinc smelting slag pretreatment: The zinc smelting slag is screened and crushed into slag fragments with a particle size of less than 2 cm for standby use; Recovery of coke pellets: The crushed slag with a particle size of less than 2 cm is subjected to two-stage wet magnetic separation. The non-magnetic materials after magnetic separation are successively passed through a jig and a spiral classifier to screen out coke pellets. The magnetic materials after magnetic separation are used as raw materials for subsequent comprehensive recovery processes and are reserved for future use. Iron concentrate recovery: the magnetic material after magnetic separation is passed through the wet first ball mill to obtain a coarse material with a grinding fineness of -200 mesh accounting for 35% to 45%; the obtained coarse material is passed through two stages of wet magnetic separation, and the magnetic concentrate after magnetic separation is filtered through a belt filter to obtain iron concentrate; the magnetic tailing material after magnetic separation is reserved; Carbon concentrate recovery: The magnetic tailings after magnetic separation are passed through a wet second ball mill to obtain fine materials with a grinding fineness of -200 mesh accounting for 75% to 85%; the fine materials are subjected to a first coarse selection and a first fine selection in sequence, and a collector and a frother are added to recover the carbon. The carbon concentrate obtained after fine selection is filtered with a ceramic filter to obtain carbon concentrate; the fine carbon concentrate tailings are reserved for later use; Silver concentrate recovery: The selected carbon concentrate tailings are sequentially subjected to one-stage roughing, two-stage concentrating and two-stage scavenging, and collectors and frothers are added to recover silver. The slurry obtained after scavenging is filtered with a chamber filter to obtain silver concentrate; the silver concentrate tailings after scavenging are reserved for later use; Tailings recovery: The silver concentrate tailings after scavenging are filtered through a ceramic filter to obtain tailings.

2. The method for high-value comprehensive utilization of zinc smelting slag according to claim 1, characterized in that: In the pellet coke recovery process, the effluent from the jig and spiral classifier enters the thickener. After gravity sedimentation and concentration in the thickener, the bottom slag is controlled to obtain pellet coke again.

3. The method for high-value comprehensive utilization of zinc smelting slag according to claim 1, characterized in that: In the iron concentrate recovery process, the magnetic concentrate after magnetic separation is filtered through a belt filter, and the resulting filtrate is sent to the chamber filter in the silver concentrate recovery process for filtration, and the silver concentrate is recovered together.

4. The method for high-value comprehensive utilization of zinc smelting slag according to claim 1, characterized in that: The carbon concentrate recovery process also includes: firstly feeding the fine material with a grinding fineness of -200 mesh accounting for 75% to 85% into the hydrocyclone, and then sequentially performing a roughing selection and a fine selection on the slurry overflowing from the hydrocyclone; and returning the sediment produced in the hydrocyclone to the first ball mill.

5. The method for high-value comprehensive utilization of zinc smelting slag according to claim 1, characterized in that: The tailings recovery process includes: subjecting the silver concentrate tailings after scavenging to strong magnetic separation, and the concentrate after strong magnetic separation is pumped to the belt filter in the iron concentrate recovery process for filtration to obtain iron concentrate; the slag slurry after strong magnetic separation is sent to the thickener, and after gravity sedimentation and concentration in the thickener, the bottom slag is filtered through a ceramic filter to obtain tailings.

6. The method for high-value comprehensive utilization of zinc smelting slag according to any one of claims 1 to 5, characterized in that: In the pellet coke recovery process, the slag fragments are subjected to two stages of wet magnetic separation, the first stage magnetic separation intensity is 3000-4000Gs, and the second stage magnetic separation intensity is 5000-6000Gs; in the iron ore recovery process, the obtained coarse material is subjected to two stages of wet magnetic separation, the first stage magnetic separation intensity is 1600-2000Gs, and the second stage magnetic separation intensity is 2200-2500Gs.

7. The method for high-value comprehensive utilization of zinc smelting slag according to any one of claims 1 to 5, characterized in that: In the carbon concentrate recovery process, the collector is kerosene and the foaming agent is 2# oil.

8. The method for high-value comprehensive utilization of zinc smelting slag according to claim 7, characterized in that: In the carbon concentrate recovery process, during the first roughing, the amount of kerosene used is 600-1000 g / t, and the amount of 2# oil used is 200-400 g / t.

9. A method for high-value comprehensive utilization of zinc smelting slag according to any one of claims 1 to 5, characterized in that: In the silver concentrate recovery process, the collector is butyrrolidone and the foaming agent is 2# oil.

10. The method for high-value comprehensive utilization of zinc smelting slag according to claim 9, characterized in that: In the silver concentrate recovery process, in the first roughing stage, the dosage of butyric acid xanthate is 400-600 g / t, and the dosage of 2# oil is 150-300 g / t; in the first scavenging stage, the dosage of butyric acid xanthate is 200-300 g / t, and the dosage of 2# oil is 75-150 g / t; in the second scavenging stage, the dosage of butyric acid xanthate is 100-150 g / t, and the dosage of 2# oil is 50-75 g / t.

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