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

Abstract

The application provides a method for high-value comprehensive utilization of zinc smelting kiln slag. The method comprises the following steps: after the broken 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 jig and a spiral classifier, and granular coke is obtained, and the magnetic materials are subjected to ball milling and then subjected to a magnetic separation + flotation process to obtain iron concentrate, carbon concentrate and silver concentrate. The method for high-value comprehensive utilization of zinc smelting kiln slag can reduce carbon emission, realize high-value utilization of the kiln slag, and has relatively simple process and equipment and high economic benefit.

Description

Technical Field

[0001] This invention relates to the field of zinc smelting kiln slag utilization technology, and in particular to a method for the high-value comprehensive utilization of zinc smelting kiln slag. Background Technology

[0002] Research on comprehensive recycling and treatment technologies for zinc kiln slag is of great significance, mainly in the following aspects: ① Zinc kiln slag contains valuable metal elements and coke. Research on comprehensive recycling and treatment technologies for zinc kiln slag can not only yield significant economic benefits but also achieve energy conservation and emission reduction, promoting the comprehensive utilization of solid waste. ② Comprehensive recovery of valuable heavy metal elements such as Ag, Zn, Pb, and Cu from zinc kiln slag can not only improve the quality of the living environment and protect public health but also facilitate the full utilization of mineral resources, improve the technological content of enterprise production, and reduce production costs.

[0003] In recent years, researchers have conducted extensive experimental studies on the comprehensive recovery of zinc kiln slag, but problems remain, including low recovery rates, low ore grades, and high processing costs. Finding a more reasonable, economical, and efficient recovery process has been a common goal for researchers.

[0004] Therefore, there is an urgent need to develop an effective method for the comprehensive utilization of zinc smelting kiln slag to ensure that a large amount of kiln slag resources can be comprehensively recycled and utilized, thereby improving resource utilization and reducing environmental impact. Summary of the Invention

[0005] In order to solve the above-mentioned technical problems, the purpose of this invention is to provide a method for the high-value comprehensive utilization of zinc smelting kiln slag that is energy-saving, emission-reducing, low-cost, economically efficient and simple.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by this invention is: a method for the comprehensive utilization of high-value zinc smelting kiln slag, comprising:

[0007] Zinc smelting kiln slag pretreatment: The zinc smelting kiln slag is screened and crushed into slag fragments with a particle size of less than 2cm for later use.

[0008] Particle coke recovery: Crushed kiln slag with a particle size of less than 2cm is subjected to two-stage wet magnetic separation. The non-magnetic material after magnetic separation is then screened by a jig and a spiral classifier to remove the particle coke. The magnetic material after magnetic separation is used as raw material for subsequent comprehensive recycling processes and is reserved for later use.

[0009] Iron concentrate recovery: The magnetic material after magnetic separation is passed through a wet ball mill to obtain coarse material with a grinding fineness of -200 mesh accounting for 35% to 45%; the obtained coarse material is passed through a two-stage wet magnetic separation, and the magnetic concentrate after magnetic separation is filtered through a belt filter to obtain iron concentrate; the magnetic tailings after magnetic separation are reserved for later use.

[0010] Carbon concentrate powder recovery: the tailings after magnetic separation are sent to a second wet ball mill to obtain fine materials with a grinding fineness of 75% to 85% of-200 mesh; the fine materials are sequentially subjected to one-stage roughing and one-stage cleaning, and carbon is recovered by adding a collector and a frother; the carbon concentrate obtained after cleaning is filtered by a ceramic filter to obtain carbon concentrate powder; the tailings of the carbon concentrate powder after cleaning are reserved;

[0011] Silver concentrate recovery: the tailings of the carbon concentrate powder after cleaning are sequentially subjected to one-stage roughing, two-stage cleaning and two-stage scavenging, and silver is recovered by adding a collector and a frother; the slurry obtained after scavenging is filtered by a van box filter to obtain silver concentrate; the tailings of the silver concentrate after scavenging are reserved;

[0012] Tailings recovery: the tailings of the silver concentrate after scavenging are filtered by a ceramic filter to obtain tailings.

[0013] Further, in the granular coke recovery process, the water discharged from the jig and the spiral classifier enters the thickener, and after gravity settling and concentration in the thickener, the bottom slag is obtained again by controlling the water to obtain granular coke.

[0014] Further, in the iron concentrate recovery process, the magnetic concentrate after magnetic separation is filtered by a belt filter, and the filtrate is sent to the van box filter in the silver concentrate recovery process for the recovery of silver concentrate.

[0015] Further, in the carbon concentrate powder recovery process, the fine materials with a grinding fineness of 75% to 85% of-200 mesh are first sent to a hydrocyclone, and then the overflow from the hydrocyclone is sequentially subjected to one-stage roughing and one-stage cleaning; the sand produced in the hydrocyclone is returned to the first ball mill.

[0016] Further, the tailings recovery process includes: the tailings of the silver concentrate after scavenging are subjected to high-intensity magnetic separation, and the concentrate after high-intensity magnetic separation is pumped to the belt filter in the iron concentrate recovery process for filtration to obtain iron concentrate; the slag slurry after high-intensity magnetic separation is sent to the thickener, and after gravity settling and concentration in the thickener, the bottom slag is filtered by a ceramic filter to obtain tailings.

[0017] Further, in the granular coke recovery process, the kiln slag is subjected to two-stage wet magnetic separation, the first-stage magnetic separation strength is 3000-4000Gs, and the second-stage magnetic separation strength is 5000-6000Gs.

[0018] Further, in the iron concentrate recovery process, the obtained coarse materials are subjected to two-stage wet magnetic separation, the first-stage magnetic separation strength is 1600-2000Gs, and the second-stage magnetic separation strength is 2200-2500Gs.

[0019] Further, in the carbon concentrate powder recovery process, the collector is kerosene, and the frother is 2# oil.

[0020] Further, in the carbon powder recovery process, the amount of kerosene used is 600-1000 g / t, and the amount of 2# oil used is 200-400 g / t.

[0021] Further, in the silver concentrate recovery process, the collector is butyl xanthate, and the frother is 2# oil.

[0022] Further, in the silver concentrate recovery process, the amount of butyl xanthate used in the first roughing is 400-600 g / t, and the amount of 2# oil used is 150-300 g / t; the amount of butyl xanthate used in the first scavenging is 200-300 g / t, and the amount of 2# oil used is 75-150 g / t; the amount of butyl xanthate used in the second scavenging is 100-150 g / t, and the amount of 2# oil used is 50-75 g / t.

[0023] Compared with the prior art, the present application has at least the following beneficial effects:

[0024] The method for high-value comprehensive utilization of zinc smelting kiln slag provided by the present application recovers and utilizes valuable elements in the kiln slag produced by the volatile kiln of the zinc smelting industry through a combined beneficiation method combining crushing, magnetic separation, gravity separation and flotation, and produces granular coke and carbon powder that can replace part of the fuel of the volatile kiln, as well as iron concentrate and silver concentrate with high grade and economic value. Not only does the method improve the resource recovery rate and reduce the impact of solid waste storage and carbon emissions on the environment, but it also further improves the economic value of the kiln slag. Moreover, the process principle and flow are relatively simple, it is a pure physical process, the cost is low, the reaction requirement is low, it can save energy and reduce emissions, it is environmentally friendly, it has high economic benefits, it has good application prospects, and it is worth popularization and application. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The method for high-value comprehensive utilization of zinc smelting kiln slag provided by the present application recovers and utilizes valuable elements in the kiln slag produced by the volatile kiln of the zinc smelting industry through a combined beneficiation method combining crushing, magnetic separation, gravity separation and flotation, and produces granular coke and carbon powder that can replace part of the fuel of the volatile kiln, as well as iron concentrate and silver concentrate with high grade and economic value. Not only does the method improve the resource recovery rate and reduce the impact of solid waste storage and carbon emissions on the environment, but it also further improves the economic value of the kiln slag. Moreover, the process principle and flow are relatively simple, it is a pure physical process, the cost is low, the reaction requirement is low, it can save energy and reduce emissions, it is environmentally friendly, it has high economic benefits, it has good application prospects, and it is worth popularization and application.

[0026] Figure 2 The method for high-value comprehensive utilization of zinc smelting kiln slag provided by the present application recovers and utilizes valuable elements in the kiln slag produced by the volatile kiln of the zinc smelting industry through a combined beneficiation method combining crushing, magnetic separation, gravity separation and flotation, and produces granular coke and carbon powder that can replace part of the fuel of the volatile kiln, as well as iron concentrate and silver concentrate with high grade and economic value. Not only does the method improve the resource recovery rate and reduce the impact of solid waste storage and carbon emissions on the environment, but it also further improves the economic value of the kiln slag. Moreover, the process principle and flow are relatively simple, it is a pure physical process, the cost is low, the reaction requirement is low, it can save energy and reduce emissions, it is environmentally friendly, it has high economic benefits, it has good application prospects, and it is worth popularization and application. DETAILED DESCRIPTION

[0027] In order to better understand the above technical solutions, the technical solutions of the embodiments of the present application will be described in detail below through the drawings and specific embodiments. It should be understood that the specific features in the embodiments of the present application and the embodiments are detailed descriptions of the technical solutions of the embodiments of the present application, and are not limitations of the technical solutions of the present application. In the case of no conflict, the technical features in the embodiments of the present application and the embodiments can be combined with each other.

[0028] In a first aspect of the embodiment of the present application, a method for high-value comprehensive utilization of zinc smelting kiln slag is provided, comprising the following steps:

[0029] Pretreatment of zinc smelting kiln slag: the zinc smelting kiln slag is sieved and crushed into kiln slag fragments with a particle size less than 2 cm for standby;

[0030] Particle coke recovery: the crushed kiln slag fragments with a particle size less than 2 cm are subjected to two-stage wet magnetic separation, and the non-magnetic material after magnetic separation is sieved by a jig and a spiral classifier to obtain particle coke; the magnetic material after magnetic separation is used as raw material for subsequent comprehensive recovery process for standby;

[0031] Iron concentrate recovery: the magnetic material after magnetic separation is subjected to wet first ball milling to obtain coarse material with a grinding fineness of-200 mesh accounting for 35% to 45%; the obtained coarse material is subjected to two-stage wet magnetic separation, and the magnetic concentrate after magnetic separation is filtered by a belt filter to obtain iron concentrate; the magnetic tailings after magnetic separation are used for standby;

[0032] Carbon concentrate powder recovery: the magnetic tailings after magnetic separation are subjected to wet second ball milling to obtain fine material with a grinding fineness of-200 mesh accounting for 75% to 85%; the fine material is subjected to one-stage roughing and one-stage cleaning, and carbon is recovered by adding a collector and a frother; the carbon concentrate obtained after cleaning is filtered by a ceramic filter to obtain carbon concentrate powder; the carbon concentrate powder tailings after cleaning are used for standby;

[0033] Silver concentrate recovery: the carbon concentrate powder tailings after cleaning are subjected to one-stage roughing, two-stage cleaning and two-stage scavenging, and silver is recovered by adding a collector and a frother; the slurry obtained after scavenging is filtered by a box filter to obtain silver concentrate; the silver concentrate tailings after scavenging are used for standby;

[0034] Tailings recovery: the silver concentrate tailings after scavenging are filtered by a ceramic filter to obtain tailings.

[0035] The method for high-value comprehensive utilization of zinc smelting kiln slag provided by the embodiment of the present application recovers and utilizes the valuable elements in the zinc smelting kiln slag by a combined beneficiation method combining crushing, magnetic separation, gravity separation and flotation, and adopts a pure physical process, thereby producing particle coke and carbon concentrate powder that can replace part of the volatile kiln fuel, and iron concentrate and silver concentrate with high grade and economic value. In addition, the tailings produced at the end of the process of the method for high-value comprehensive utilization of zinc smelting kiln slag provided by the embodiment of the present application has a very low content of valuable elements and does not have recycling value, and belongs to general solid waste, which can be used as raw material for building materials and will not have a bad impact on the environment.

[0036] In some possible embodiments, in the particle coke recovery process, the water discharged from the jig and the spiral classifier enters the thickener, and after concentration by gravity settling in the thickener, the bottom sludge is controlled for water to obtain particle coke again.

[0037] Through gravity settling concentration and bottom slag water control of the thickener, the granular coke is further recovered, and the resource recovery rate is increased again, and the pollution to the environment is reduced.

[0038] In some possible embodiments, in the iron concentrate recovery process, the magnetic concentrate after magnetic separation is filtered by a belt filter, and the obtained filtrate is sent to a compartment filter in the silver concentrate recovery process for filtering, and the recovery of silver concentrate is carried out together.

[0039] In the iron concentrate recovery process, the obtained coarse material is subjected to two-stage wet magnetic separation, and a high-silver iron magnetic concentrate containing iron≥60wt% and silver>100g / t is produced. After filtering the magnetic concentrate after magnetic separation, part of the valuable metals iron and silver still remains in the filtrate. The filtrate is reused to prevent resource waste.

[0040] In some possible embodiments, the carbon concentrate recovery process further includes: first sending the fine material with a grinding fineness of-200 mesh accounting for 75% to 85% to a hydrocyclone, and then sequentially performing one-stage roughing and one-stage cleaning on the overflow slurry of the hydrocyclone; and the sand produced in the hydrocyclone is returned to the first ball mill.

[0041] The fine material with a grinding fineness of-200 mesh accounting for 75% to 85% first enters the hydrocyclone. The hydrocyclone can quickly separate the particle size of the ore particles. The fine material with a particle size of about-200 mesh is preferentially overflowed into the flotation system. The sand in the hydrocyclone is returned to the first ball mill to form a non-magnetic material grinding closed circuit, saving resources and preventing waste.

[0042] In some possible embodiments, the tailings recovery process includes: subjecting the silver concentrate tailings after sweeping selection to strong magnetic separation, and pumping the concentrate after strong magnetic separation to a belt filter in the iron concentrate recovery process for filtering to obtain iron concentrate; and sending the slag slurry after strong magnetic separation to a thickener, and filtering the bottom slag after gravity settling concentration of the thickener by a ceramic filter to obtain tailings.

[0043] The iron concentrate in the silver concentrate tailings is further recovered by strong magnetic separation, effectively increasing the utilization rate of resources, and effectively reducing the content of valuable elements in the tailings, which can be used as a general solid waste as a raw material for building materials, without adversely affecting the environment.

[0044] In some possible embodiments, in the granular coke recovery process, the kiln slag crushed material is subjected to two-stage wet magnetic separation, the first-stage magnetic separation strength is 3000-4000Gs, and the second-stage magnetic separation strength is 5000-6000Gs.

[0045] The magnetic separation intensity has a significant impact on the magnetic separation. Too low magnetic separation intensity can improve the yield but the product grade is too low to meet the actual recycling demand. On the contrary, too high magnetic separation intensity can reduce the yield, which will reduce the recovery rate in both cases. In the granular coke recovery process, through a large number of experiments, it is found that the two-stage magnetic separation intensity of 3000-4000Gs and 5000-6000Gs can effectively ensure the product grade and recovery rate.

[0046] In some possible embodiments, in the iron concentrate recovery process, the obtained coarse material is subjected to two-stage wet magnetic separation, the first-stage magnetic separation intensity is 1600-2000Gs, and the second-stage magnetic separation intensity is 2200-2500Gs.

[0047] The magnetic separation intensity has a significant impact on the magnetic separation. Too low magnetic separation intensity can improve the yield but the product grade is too low to meet the actual recycling demand. On the contrary, too high magnetic separation intensity can reduce the yield, which will reduce the recovery rate in both cases. In the granular coke recovery process, through a large number of experiments, it is found that the two-stage magnetic separation intensity of 1600-2000Gs and 2200-2500Gs can effectively ensure the product grade and recovery rate.

[0048] In some possible embodiments, in the carbon concentrate powder recovery process, the collector is kerosene, and the frother is 2# oil.

[0049] In the carbon concentrate powder recovery process, kerosene is used as the collector. Kerosene has good wettability, can increase the hydrophobicity of the mineral surface, promote the adsorption between the mineral ions and the bubbles, improve the flotation effect, and in addition, kerosene can form a bubble settling film on the surface of the bubbles, making the foam more stable, avoiding the deformation and rupture of the bubbles, and increasing the contact between the particles and the bubbles. 2# oil is used as the frother. 2# oil has strong frothing property and can produce a large number of uniform bubbles with appropriate viscosity.

[0050] Further, in the carbon concentrate powder recovery process, in the first-stage roughing, the amount of kerosene used is 600-1000g / t, and the amount of 2# oil used is 200-400g / t.

[0051] With the increase of the amount of the reagent used for the flotation carbon, the yield and recovery rate of the carbon will increase, 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 addition cannot continuously improve the recovery rate but will increase the reagent cost. Through a large number of experiments, it is found that in the carbon concentrate powder recovery process, in the first-stage roughing, the amount of kerosene used is 600-1000g / t, and the amount of 2# oil used is 200-400g / t, which can obtain carbon concentrate powder with a carbon grade of ≥60%.

[0052] In some possible embodiments, in the silver concentrate recovery process, the collector is butyl xanthate, and the frother is 2# oil.

[0053] In the silver concentrate recovery process, butyl xanthate is used as the collector, which can selectively adsorb on the surface of the target mineral, promote its adhesion on the bubble, and strengthen the separation. In addition, butyl xanthate also has certain foaming performance. 2# oil is used as the foaming agent, which has strong foaming performance and can produce a large number of uniform bubbles with appropriate viscosity.

[0054] Further, in the silver concentrate recovery process, the dosage of butyl xanthate is 400-600 g / t and the dosage of 2# oil is 150-300 g / t in the first roughing; the dosage of butyl xanthate is 200-300 g / t and the dosage of 2# oil is 75-150 g / t in the first scavenging; and the dosage of butyl xanthate is 100-150 g / t and the dosage of 2# oil is 50-75 g / t in the second scavenging.

[0055] With the increase of the dosage of the silver flotation reagent, the yield and recovery rate of silver will increase, but with the increase of the dosage, the recovery rate gradually stabilizes and no longer has obvious increase, and the grade gradually decreases. Excessive addition cannot continuously improve the recovery rate, but increases the cost of the reagent. Through a large number of experiments, it is found that in the silver concentrate recovery process, the dosage of butyl xanthate is 400-600 g / t and the dosage of 2# oil is 150-300 g / t in the first roughing; the dosage of butyl xanthate is 200-300 g / t and the dosage of 2# oil is 75-150 g / t in the first scavenging; and the dosage of butyl xanthate is 100-150 g / t and the dosage of 2# oil is 50-75 g / t in the second scavenging, so that the silver concentrate with a silver grade of ≥100 g / t can be obtained.

[0056] The method for high-value comprehensive utilization of zinc smelting kiln slag provided by the application is a research on the comprehensive recovery and utilization of carbon and silver from zinc smelting kiln slag. Starting from the process mineralogy research, the beneficiation process test research and analysis are systematically carried out to explore the best process parameters, and the process flow for recovering carbon and silver elements from the zinc smelting kiln slag is proposed, which provides a reference basis for the comprehensive utilization of secondary mineral resources, the improvement of the environment, the improvement of the production efficiency of enterprises and the creation of social benefits. At the same time, the method for high-value comprehensive utilization of zinc smelting kiln slag provided by the application has low requirements for the water quality in the process of beneficiation, can be collected and reused, and will not produce external drainage, so as not to cause the burden of zero discharge of industrial wastewater in the actual application process, and to reduce the influence on the environment. The method for high-value comprehensive utilization of zinc smelting kiln slag provided by the application not only improves the recovery rate of resources, reduces the influence of solid waste storage and carbon emission on the environment, but also further improves the economic value of the kiln slag.

[0057] Example 1

[0058] Reference Figure 1 and Figure 2The embodiment provides a method for high-value comprehensive utilization of zinc smelting kiln slag, and comprises the following steps.

[0059] Step 1: zinc smelting kiln slag pretreatment: the zinc smelting kiln slag is crushed into kiln slag crushed materials with a particle size of less than 2 cm through screening and crushing, and is ready for use.

[0060] Preferably, in the embodiment, the zinc smelting kiln slag is sequentially subjected to grizzly classification, first crushing, iron block removal by a belt iron separator, screening by a linear vibrating screen and second crushing, and is crushed into kiln slag crushed materials with a particle size of less than 2 cm, and is ready for use.

[0061] As an exemplary illustration, the specific process is as follows:

[0062] The raw material zinc smelting kiln slag is subjected to grizzly classification, the grizzly screen aperture is 150 mm, the grizzly screen undersize part enters a belt conveyor through a chute, the grizzly screen oversize part enters a first jaw crusher, the crushed kiln slag enters the belt conveyor, the belt conveyor is provided with a belt iron separator above the belt conveyor to remove iron blocks, the kiln slag after removal of the iron blocks is conveyed to a linear vibrating screen by the belt conveyor, the linear vibrating screen aperture is 20 mm*20 mm, the oversize part of the kiln slag enters a second jaw crusher, and is crushed into crushed materials with a particle size of less than 2 cm; the crushed kiln slag and the kiln slag undersize part of the linear vibrating screen enter a belt conveyor, enter a powder bin and are ready for use.

[0063] In order to prevent dust from being generated in the process of crushing the kiln slag, the grizzly classification is performed while water is used for flushing, so that the kiln slag is kept moist to prevent dust from being generated in the crushing process, and small particles attached to large-particle kiln slag are flushed down for better separation and prevention of iron blocks from taking away part of the small-particle carbon and thus reducing the carbon recovery rate.

[0064] Step 2: particle coke recovery: the crushed kiln slag crushed materials with a particle size of less than 2 cm are subjected to two-stage wet magnetic separation, non-magnetic materials after the magnetic separation are sequentially screened out of particle coke by a jigging machine and a spiral classifier, and magnetic materials after the magnetic separation enter a comprehensive recovery bin as raw materials for a subsequent comprehensive recovery process and are ready for use.

[0065] Preferably, in the embodiment, water discharged from the jigging machine and the spiral classifier enters a thickener, and after gravity settling and concentration by the thickener, bottom slag is subjected to water control again to obtain particle coke again.

[0066] As an exemplary illustration, the specific process is as follows:

[0067] The kiln slag crushed material with particle size less than 2 cm is subjected to two-stage wet magnetic separation, the first-stage magnetic separation intensity is 3000 Gs, and the second-stage magnetic separation intensity is 5000 Gs, the non-magnetic material after the two-stage magnetic separation is subjected to screening by a jig and a spiral classifier in sequence to obtain granular coke, the water discharged from the jig and the spiral classifier is fed into a first thickener, the bottom slurry after gravity sedimentation and concentration in the first thickener is subjected to water control to obtain granular coke again, and the overflow of the first thickener is fed into a circulating water pool.

[0068] Step 3: Iron concentrate recovery: the magnetic material after the magnetic separation is subjected to wet first-stage ball milling to obtain coarse material with a grinding fineness of 35% of -200 mesh; the coarse material is subjected to two-stage wet magnetic separation, the magnetic concentrate after the magnetic separation is subjected to filtration by a belt filter to obtain iron concentrate; the magnetic tailings after the magnetic separation are reserved.

[0069] Preferably, in the embodiment, the magnetic concentrate after the magnetic separation is subjected to filtration by the belt filter, and the obtained filtrate is fed into a compartment filter in the silver concentrate recovery process for recovery of silver concentrate.

[0070] As an example, specifically:

[0071] The magnetic material in the comprehensive recovery bin is fed into a wet first-stage ball mill by a disc feeder to obtain coarse material with a grinding fineness of 35% of -200 mesh. The slurry after the ball milling is subjected to water addition and slurry preparation and then subjected to two-stage wet magnetic separation, the first-stage magnetic separation intensity is 1600 Gs, and the second-stage magnetic separation intensity is 2200 Gs, the magnetic concentrate (high-silver iron concentrate slurry) after the two-stage magnetic separation is pumped to a belt vacuum filter for filtration to obtain iron concentrate. The obtained filtrate and the slurry after washing the filter cloth are pumped to a third thickener in the silver concentrate recovery process, and then subjected to filtration by a compartment filter to recover silver concentrate. The magnetic tailings after the magnetic separation are reserved.

[0072] Step 4: Carbon concentrate powder recovery: the magnetic tailings after the magnetic separation are subjected to wet second-stage ball milling to obtain fine material with a grinding fineness of 75% of -200 mesh; the fine material is subjected to one-stage roughing and one-stage cleaning in sequence, a collector and a frother are added to recover carbon, the carbon concentrate obtained after the cleaning is subjected to filtration by a ceramic filter to obtain carbon concentrate powder; the carbon concentrate powder tailings after the cleaning are reserved.

[0073] Preferably, in the embodiment, the fine material with a grinding fineness of 75% of -200 mesh is fed into a hydrocyclone, and the slurry overflowing from the hydrocyclone is subjected to one-stage roughing and one-stage cleaning in sequence; the sand generated in the hydrocyclone is returned to the first-stage ball mill.

[0074] Preferably, in the embodiment, the collector is kerosene, and the frother is 2# oil.

[0075] Preferably, in this embodiment, the amount of kerosene used in the first roughing is 600 g / t, and the amount of 2# oil used is 200 g / t.

[0076] As an exemplary illustration, the details are as follows:

[0077] The tailings after magnetic separation are fed into a wet second ball mill for grinding, to obtain fine materials with a grinding fineness of -200 mesh 75%, which are pumped into a hydrocyclone. The overflow of the hydrocyclone is fed into a stirring barrel for pulp conditioning, and then subjected to a carbon flotation process. The first roughing and the first cleaning are sequentially performed. In the first roughing, the amount of kerosene used is 600 g / t, and the amount of 2# oil used is 200 g / t. The carbon is recovered, and the carbon concentrate obtained after cleaning is pumped into a second thickener. After gravity sedimentation and concentration in the second thickener, the bottom slurry is pumped into a buffer stirring barrel, and then filtered by a ceramic filter after conditioning, to obtain carbon concentrate powder. The overflow of the second thickener is fed into a circulating water pool. The carbon concentrate tailings after cleaning are reserved for use.

[0078] Step 5: Silver concentrate recovery: The carbon concentrate tailings after cleaning are sequentially subjected to the first roughing, the second cleaning, and the second scavenging. The silver is recovered by adding a collector and a frother. The slurry obtained after scavenging is filtered by a box filter, to obtain silver concentrate. The silver concentrate tailings after scavenging are reserved for use.

[0079] Preferably, in this embodiment, the collector is butyl xanthate, and the frother is 2# oil.

[0080] Preferably, in this embodiment, the amount of butyl xanthate used in the first roughing is 400 g / t, and the amount of 2# oil used is 200 g / t. The amount of butyl xanthate used in the first scavenging is 200 g / t, and the amount of 2# oil used is 100 g / t. The amount of butyl xanthate used in the second scavenging is 100 g / t, and the amount of 2# oil used is 50 g / t.

[0081] As an exemplary illustration, the details are as follows:

[0082] The carbon concentrate tailings after scavenging are lifted into a stirring barrel, and then subjected to a silver flotation process after conditioning. The tailings are sequentially subjected to the first roughing, the second cleaning, and the second scavenging. In the first roughing, the amount of butyl xanthate used is 400 g / t, and the amount of 2# oil used is 200 g / t. In the first scavenging, the amount of butyl xanthate used is 200 g / t, and the amount of 2# oil used is 100 g / t. In the second scavenging, the amount of butyl xanthate used is 100 g / t, and the amount of 2# oil used is 50 g / t. The slurry obtained after scavenging is pumped into a third thickener. After gravity sedimentation and concentration in the third thickener, the bottom slurry is pumped into a buffer stirring barrel, and then filtered by a box filter after conditioning by a pressure filter, to obtain silver concentrate. The overflow of the third thickener is fed into a circulating water pool. The silver concentrate tailings after scavenging are reserved for use.

[0083] Step 6: tailings recovery: the silver concentrate tailings after scavenging are filtered by a ceramic filter to obtain tailings.

[0084] Preferably, in this embodiment, the silver concentrate tailings after scavenging are subjected to high-intensity magnetic separation, and the concentrate after high-intensity magnetic separation is pumped into a belt filter in the iron concentrate recovery process for filtration to obtain the iron concentrate; the slurry after high-intensity magnetic separation is sent into a thickener, and after gravity settling and concentration by the thickener, the bottom sludge is filtered by a ceramic filter to obtain the tailings.

[0085] As an exemplary illustration, specifically:

[0086] The silver concentrate tailings after scavenging are subjected to high-intensity magnetic separation, and the concentrate after high-intensity magnetic separation is pumped into a belt vacuum filter in the iron concentrate recovery process for filtration to obtain the iron concentrate; the slurry after high-intensity magnetic separation is pumped by a slurry pump into a fourth thickener, and after gravity settling and concentration by the thickener, the bottom sludge is pumped into a buffer mixing barrel, and after slurry adjustment, it is filtered by a ceramic filter to obtain the tailings. The overflow of the fourth thickener enters a circulating water pool.

[0087] Embodiment 2

[0088] Referring to Figure 1 and Figure 2 , this embodiment provides a method for high-value comprehensive utilization of zinc smelting kiln slag, comprising the following steps:

[0089] Step 1: zinc smelting kiln slag pretreatment: the zinc smelting kiln slag is sieved and crushed into kiln slag crushed material with a particle size of less than 2 cm for standby use.

[0090] Preferably, in this embodiment, the zinc smelting kiln slag is sequentially subjected to grizzly classification, first crushing, iron block removal by a belt iron remover, linear vibration screen screening, and second crushing to be crushed into kiln slag crushed material with a particle size of less than 2 cm for standby use.

[0091] As an exemplary illustration, specifically:

[0092] The raw material zinc smelting kiln slag is subjected to grizzly classification, the grizzly screen aperture is 150 mm, the grizzly screen undersize is fed into a belt conveyor by a chute, the grizzly screen oversize is fed into a first jaw crusher, the crushed kiln slag is fed into a belt conveyor, a belt iron remover is suspended above the belt conveyor to remove iron blocks, the kiln slag after removal of iron blocks is fed into a linear vibration screen by the belt conveyor, the linear vibration screen aperture is 20 mm*20 mm, the oversize of the linear vibration screen is fed into a second jaw crusher to be crushed into crushed material with a particle size of less than 2 cm, and the crushed kiln slag and the kiln slag undersize of the linear vibration screen are fed into a belt conveyor to enter a powder bin for standby use.

[0093] To prevent dust from being generated in the process of crushing the kiln slag, water is used to flush while the kiln slag is graded by the grizzly screen. On the one hand, the kiln slag is kept moist to prevent dust from being generated in the process of crushing, and on the other hand, the fine particles attached to the large-particle kiln slag are flushed down for better separation, so as to prevent the iron block from taking away part of the fine-particle carbon and thus reduce the carbon recovery rate.

[0094] Step 2: Particle coke recovery: the crushed kiln slag with a particle size less than 2 cm is subjected to two-stage wet magnetic separation, the non-magnetic material after the magnetic separation is sequentially screened by the jigging machine and the spiral classifier to obtain the particle coke, and the magnetic material after the magnetic separation is sent to a comprehensive recovery bin as raw material for a subsequent comprehensive recovery process.

[0095] Preferably, in the present embodiment, the water discharged from the jigging machine and the spiral classifier enters the thickener, and after gravity settling and concentration by the thickener, the bottom sludge is subjected to water control to obtain the particle coke again.

[0096] As an exemplary illustration, specifically:

[0097] The crushed kiln slag with a particle size less than 2 cm is subjected to two-stage wet magnetic separation, the first-stage magnetic separation strength is 3500Gs, and the second-stage magnetic separation strength is 5500Gs, the non-magnetic material after the two-stage magnetic separation is sequentially screened by the jigging machine and the spiral classifier to obtain the particle coke, and the water discharged from the jigging machine and the spiral classifier enters the first thickener, and after gravity settling and concentration by the first thickener, the bottom sludge is subjected to water control to obtain the particle coke again, and the overflow of the first thickener enters a circulating water pool. The magnetic material after the magnetic separation is sent to a comprehensive recovery bin as raw material for a subsequent comprehensive recovery process.

[0098] Step 3: Iron concentrate recovery: the magnetic material after the magnetic separation is subjected to wet first-stage ball milling to obtain coarse material with a grinding fineness of 40% of-200 mesh, the obtained coarse material is subjected to two-stage wet magnetic separation, the magnetic concentrate after the magnetic separation is filtered by a belt filter to obtain the iron concentrate, and the magnetic tailings after the magnetic separation are reserved;

[0099] Preferably, in the present embodiment, the magnetic concentrate after the magnetic separation is filtered by the belt filter, and the obtained filtrate is sent to a compartment filter in the silver concentrate recovery process for filtering to recover the silver concentrate.

[0100] As an exemplary illustration, specifically:

[0101] The magnetic material in the comprehensive recovery bin is fed into a wet first ball mill by a disc feeder for grinding, to obtain coarse material with a grinding fineness of -200 mesh accounting for 40%. The slurry after ball milling is adjusted by adding water and then enters two-stage wet magnetic separation, with a first-stage magnetic intensity of 1800Gs and a second-stage magnetic intensity of 2300Gs. The magnetic concentrate (high-silver iron concentrate slurry) after the two-stage 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 a compartment filter in the silver concentrate recovery process for filtration, to jointly recover silver concentrate. The magnetic tailings after the magnetic separation are reserved.

[0102] Step 4: Carbon concentrate recovery: the magnetic tailings after the magnetic separation are ground by 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 one-stage roughing and one-stage cleaning in sequence, with the addition of a collector and a frother for carbon recovery. The carbon concentrate obtained after the cleaning is filtered by a ceramic filter, to obtain carbon concentrate powder. The carbon concentrate powder tailings after the cleaning are reserved.

[0103] Preferably, in the present embodiment, the fine material with a grinding fineness of -200 mesh accounting for 80% is first fed into a hydrocyclone, and then the overflow of the hydrocyclone is subjected to one-stage roughing and one-stage cleaning in sequence. The sand generated in the hydrocyclone is returned to the first ball mill.

[0104] Preferably, in the present embodiment, the collector is kerosene, and the frother is 2# oil.

[0105] Preferably, in the present embodiment, the amount of kerosene used in the one-stage roughing is 800g / t, and the amount of 2# oil used is 300g / t.

[0106] As an exemplary illustration, specifically:

[0107] The magnetic tailings after the magnetic separation are fed into a wet second ball mill for grinding, to obtain fine material with a grinding fineness of -200 mesh accounting for 80%. The fine material is pumped to a hydrocyclone, and the overflow of the hydrocyclone is subjected to one-stage roughing and one-stage cleaning in sequence after being adjusted by a stirring barrel. The carbon is recovered in the one-stage roughing, with the amount of kerosene used being 800g / t and the amount of 2# oil used being 300g / t. The carbon concentrate obtained after the cleaning is pumped to a second thickener, and the bottom sludge is pumped to a buffer stirring barrel after being concentrated by gravity sedimentation in the second thickener. The carbon concentrate powder is obtained by filtering the slurry after being adjusted by the buffer stirring barrel using a ceramic filter. The overflow of the second thickener enters a circulating water pool. The carbon concentrate powder tailings after the cleaning are reserved. The sand generated in the hydrocyclone is returned to the first ball mill, to form a non-magnetic material grinding closed circuit.

[0108] Step 5: Silver concentrate recovery: the carbon concentrate powder tailings after the selection are sequentially subjected to one-stage roughing, two-stage cleaning and two-stage scavenging, silver is recovered by adding a collector and a frother, the slurry obtained after the scavenging is filtered by a box filter to obtain a silver concentrate; the silver concentrate tailings after the scavenging are reserved.

[0109] Preferably, in the embodiment, the collector is butyl xanthate and the frother is 2# oil.

[0110] Preferably, in the embodiment, the dosage of butyl xanthate is 500 g / t and the dosage of 2# oil is 200 g / t in the one-stage roughing; the dosage of butyl xanthate is 250 g / t and the dosage of 2# oil is 100 g / t in the first-stage scavenging; the dosage of butyl xanthate is 125 g / t and the dosage of 2# oil is 50 g / t in the second-stage scavenging.

[0111] As an exemplary illustration, specifically:

[0112] The carbon concentrate powder tailings after the scavenging are put into a lifting stirring barrel, and after the pulp conditioning, the silver flotation process is carried out. The tailings are sequentially subjected to one-stage roughing, two-stage cleaning and two-stage scavenging, the dosage of butyl xanthate is 500 g / t and the dosage of 2# oil is 200 g / t in the one-stage roughing; the dosage of butyl xanthate is 250 g / t and the dosage of 2# oil is 100 g / t in the first-stage scavenging; the dosage of butyl xanthate is 125 g / t and the dosage of 2# oil is 50 g / t in the second-stage scavenging. The slurry obtained after the scavenging is pumped to a third thickener, and after the gravity sedimentation concentration of the third thickener, the bottom sludge is pumped to a buffer stirring barrel, and after the pulp conditioning, the sludge is pumped to a box filter by a pressure filter pump for filtration to obtain a silver concentrate, and the overflow of the third thickener is put into a circulating water pool. The silver concentrate tailings after the scavenging are reserved.

[0113] Step 6: Tailings recovery: the silver concentrate tailings after the scavenging are filtered by a ceramic filter to obtain tailings.

[0114] Preferably, in the embodiment, the silver concentrate tailings after the scavenging are subjected to high-intensity magnetic separation, the concentrate after the high-intensity magnetic separation is pumped to a belt filter in the iron concentrate recovery process for filtration to obtain an iron concentrate; the slurry after the high-intensity magnetic separation is put into a thickener, and after the gravity sedimentation concentration of the thickener, the bottom sludge is filtered by a ceramic filter to obtain tailings.

[0115] As an exemplary illustration, specifically:

[0116] The silver concentrate tailings after the scavenging are subjected to high-intensity magnetic separation, the concentrate after the high-intensity magnetic separation is pumped to a belt vacuum filter in the iron concentrate recovery process for filtration to obtain an iron concentrate; the slurry after the high-intensity magnetic separation is pumped to a fourth thickener by a slurry pump, and after the gravity sedimentation concentration of the thickener, the bottom sludge is pumped to a buffer stirring barrel, and after the pulp conditioning, the sludge is filtered by a ceramic filter to obtain tailings. The overflow of the fourth thickener is put into a circulating water pool.

[0117] Example 3

[0118] Referring to Figure 1 and Figure 2 , the present embodiment provides a method for high-value comprehensive utilization of zinc smelting kiln slag, comprising the following steps:

[0119] Step 1: Zinc smelting kiln slag pretreatment: the zinc smelting kiln slag is crushed into kiln slag fragments with a particle size of less than 2 cm through screening and crushing, and is ready for use.

[0120] Preferably, in the present embodiment, the zinc smelting kiln slag is sequentially subjected to grizzly classification, first crushing, iron block removal by belt iron separator, screening by linear vibrating screen, and second crushing, and is crushed into kiln slag fragments with a particle size of less than 2 cm, and is ready for use.

[0121] As an exemplary illustration, specifically:

[0122] The raw material zinc smelting kiln slag is subjected to grizzly classification, the grizzly screen aperture is 150 mm, the grizzly screen undersize portion enters the belt conveyor through the chute, the grizzly screen oversize portion enters the first jaw crusher, the crushed kiln slag enters the belt conveyor, the belt conveyor is suspended with a belt iron separator above to remove iron blocks, the kiln slag after removal of iron blocks is conveyed by the belt conveyor to the linear vibrating screen, the linear vibrating screen aperture is 20 mm*20 mm, the oversize portion of the kiln slag enters the second jaw crusher, and is crushed into fragments with a particle size of less than 2 cm, and the crushed kiln slag and the kiln slag undersize portion of the linear vibrating screen enter the belt conveyor, enter the powder bin, and are ready for use.

[0123] In order to prevent dust from being generated in the process of crushing the kiln slag, water is used for flushing at the same time of grizzly classification, on the one hand to keep the kiln slag moist to prevent dust from being generated during crushing, and on the other hand to flush the fine particles attached to the large particle kiln slag down for better separation, to prevent the iron blocks from taking away part of the fine particle carbon and thus reduce the carbon recovery rate.

[0124] Step 2: Particle coke recovery: the crushed kiln slag fragments with a particle size of less than 2 cm are subjected to two-stage wet magnetic separation, the non-magnetic material after magnetic separation is screened out of particle coke by the jigger and the spiral classifier in turn; the magnetic material after magnetic separation enters the comprehensive recovery bin as raw material for the subsequent comprehensive recovery process, and is ready for use.

[0125] Preferably, in the present embodiment, the water discharged from the jigger and the spiral classifier enters the thickener, and after gravity settling and concentration by the thickener, the bottom sludge is obtained again as particle coke by controlling water.

[0126] As an exemplary illustration, specifically:

[0127] The kiln slag crushed material with particle size less than 2 cm is subjected to two-stage wet magnetic separation, the first-stage magnetic separation intensity is 4000Gs, and the second-stage magnetic separation intensity is 6000Gs, the non-magnetic material after the two-stage magnetic separation is subjected to screening by a jig and a spiral classifier in sequence to obtain granular coke, the water discharged from the jig and the spiral classifier is fed into a first thickener, the bottom slurry after gravity settling and concentration in the first thickener is subjected to water control to obtain granular coke again, and the overflow of the first thickener is fed into a circulating water pool. The magnetic material after the magnetic separation is fed into a comprehensive recovery bin as raw material for a subsequent comprehensive recovery process, and is reserved.

[0128] Step 3: Iron concentrate recovery: the magnetic material after the magnetic separation is subjected to wet first-stage ball milling to obtain coarse material with grinding fineness of-200 mesh 45%; the coarse material is subjected to two-stage wet magnetic separation, the magnetic concentrate after the magnetic separation is subjected to filtration by a belt filter to obtain iron concentrate; the magnetic tailings after the magnetic separation are reserved.

[0129] Preferably, in this embodiment, the magnetic concentrate after the magnetic separation is subjected to filtration by the belt filter, and the obtained filtrate is fed into a compartment filter in the silver concentrate recovery process for filtration to recover silver concentrate.

[0130] As an example, specifically:

[0131] The magnetic material in the comprehensive recovery bin is fed into a wet first-stage ball mill by a disc feeder to obtain coarse material with grinding fineness of-200 mesh 45%. The slurry after the ball milling is subjected to water addition and slurry preparation, and then subjected to two-stage 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 the two-stage magnetic separation is pumped to a belt vacuum filter for filtration to obtain iron concentrate. The obtained filtrate and the slurry after washing the filter cloth are pumped to a compartment filter in the silver concentrate recovery process for filtration to recover silver concentrate. The magnetic tailings after the magnetic separation are reserved.

[0132] Step 4: Carbon concentrate powder recovery: the magnetic tailings after the magnetic separation are subjected to wet second-stage ball milling to obtain fine material with grinding fineness of-200 mesh 85%; the fine material is subjected to one-stage roughing and one-stage cleaning in sequence, carbon is recovered by adding a collector and a frother, the carbon concentrate obtained after the cleaning is subjected to filtration by a ceramic filter to obtain carbon concentrate powder; the carbon concentrate powder tailings after the cleaning are reserved.

[0133] Preferably, in this embodiment, the fine material with grinding fineness of-200 mesh 85% is first fed into a hydrocyclone, and then the slurry overflowing from the hydrocyclone is subjected to one-stage roughing and one-stage cleaning in sequence; the sand produced in the hydrocyclone is returned to the first-stage ball mill.

[0134] Preferably, in this embodiment, the collector is kerosene, and the frother is 2# oil.

[0135] Preferably, in this embodiment, the amount of kerosene used in the first roughing is 1000g / t, and the amount of 2# oil used is 400g / t.

[0136] As an exemplary illustration, the details are as follows:

[0137] The tailings after magnetic separation are fed into a wet second ball mill for grinding, to obtain fine materials with a grinding fineness of -200 mesh 85%, which are pumped into a hydrocyclone. The overflow of the hydrocyclone is fed into a stirring barrel for pulp conditioning, and then subjected to a carbon flotation process. The first roughing and the first cleaning are sequentially performed. In the first roughing, the amount of kerosene used is 1000g / t, and the amount of 2# oil used is 400g / t. The carbon is recovered, and the carbon concentrate obtained after cleaning is pumped into a second thickener, which is subjected to gravity sedimentation and concentration. The bottom slurry is pumped into a buffer stirring barrel, which is subjected to pulp conditioning and then filtered by a ceramic filter to obtain carbon concentrate powder. The overflow of the second thickener is fed into a circulating water pool. The carbon concentrate tailings after cleaning are reserved for use.

[0138] Step 5: Silver concentrate recovery: The carbon concentrate tailings after cleaning are sequentially subjected to the first roughing, the second cleaning, and the second scavenging. Collectors and frothers are added to recover silver. The slurry obtained after scavenging is filtered by a box filter to obtain silver concentrate. The silver concentrate tailings after scavenging are reserved for use.

[0139] Preferably, in this embodiment, the collector is butyl xanthate, and the frother is 2# oil.

[0140] Preferably, in this embodiment, the amount of butyl xanthate used in the first roughing is 600g / t, and the amount of 2# oil used is 300g / t. The amount of butyl xanthate used in the first scavenging is 300g / t, and the amount of 2# oil used is 150g / t. The amount of butyl xanthate used in the second scavenging is 150g / t, and the amount of 2# oil used is 75g / t.

[0141] As an exemplary illustration, the details are as follows:

[0142] The carbon concentrate tailings after scavenging are fed into a lifting stirring barrel, which is subjected to pulp conditioning and then subjected to a silver flotation process. The first roughing, the second cleaning, and the second scavenging are sequentially performed. In the first roughing, the amount of butyl xanthate used is 600g / t, and the amount of 2# oil used is 300g / t. In the first scavenging, the amount of butyl xanthate used is 300g / t, and the amount of 2# oil used is 150g / t. In the second scavenging, the amount of butyl xanthate used is 150g / t, and the amount of 2# oil used is 75g / t. The slurry obtained after scavenging is pumped into a third thickener, which is subjected to gravity sedimentation and concentration. The bottom slurry is pumped into a buffer stirring barrel, which is subjected to pulp conditioning and then filtered by a box filter to obtain silver concentrate. The overflow of the third thickener is fed into a circulating water pool. The silver concentrate tailings after scavenging are reserved for use.

[0143] Step 6: tailings recovery: the silver concentrate tailings after scavenging are filtered by a ceramic filter to obtain tailings.

[0144] Preferably, in the present embodiment, the silver concentrate tailings after scavenging are subjected to high-intensity magnetic separation, and the concentrate after high-intensity magnetic separation is pumped into a belt filter in the iron concentrate recovery process for filtration to obtain the iron concentrate; the residue slurry after high-intensity magnetic separation is sent into a thickener, and after concentration by gravity settling in the thickener, the bottom residue is filtered by a ceramic filter to obtain tailings.

[0145] As an example, specifically:

[0146] The silver concentrate tailings after scavenging are subjected to high-intensity magnetic separation, and the concentrate after high-intensity magnetic separation is pumped into a belt vacuum filter in the iron concentrate recovery process for filtration to obtain the iron concentrate; the residue slurry after high-intensity magnetic separation is pumped by a residue slurry pump into a fourth thickener, and after concentration by gravity settling in the thickener, the bottom residue is pumped into a buffer mixing tank, and after slurry adjustment, it is filtered by a ceramic filter to obtain tailings. The overflow of the fourth thickener enters a circulating water pool.

[0147] Comparative Example 1

[0148] Referring to Figure 1 and Figure 2 , the present embodiment provides a method for high-value comprehensive utilization of zinc smelting kiln slag, comprising the following steps:

[0149] Step 1: zinc smelting kiln slag pretreatment: the raw material zinc smelting kiln slag is classified by a grizzly screen, the grizzly screen has a hole diameter of 150 mm, the undersize of the grizzly screen enters a chute and then a belt conveyor, the oversize of the grizzly screen enters a first jaw crusher, the crushed kiln slag enters the belt conveyor, a belt de-ironer is suspended above the belt conveyor to remove iron blocks, and the kiln slag after removing the iron blocks is conveyed by the belt conveyor to a linear vibrating screen, the linear vibrating screen has a hole diameter of 20 mm*20 mm, the oversize of the linear vibrating screen enters a second jaw crusher to be crushed into crushed material with a particle size of less than 2 cm, and the crushed kiln slag and the kiln slag undersize of the linear vibrating screen enter the belt conveyor and then a powder bin for standby use.

[0150] In order to prevent dust from being generated during the crushing of the kiln slag, the grizzly screen is washed with water at the same time, on the one hand to keep the kiln slag moist to prevent dust from being generated during crushing, and on the other hand to wash the fine particles attached to the large particles of kiln slag to achieve better separation and prevent the iron blocks from taking away part of the fine particles of carbon, thereby reducing the carbon recovery rate.

[0151] Step 2: Granular coke recovery: The crushed kiln slag with particle size less than 2 cm is subjected to two-stage wet magnetic separation, the first stage magnetic separation intensity is 1000Gs, and the second stage magnetic separation intensity is 2000Gs. The non-magnetic material after two-stage magnetic separation is screened by a jigger and a spiral classifier to obtain granular coke. The water from the jigger and the spiral classifier is discharged into the first thickener, and the bottom slurry is obtained again after gravity settling and concentration in the first thickener. The overflow of the first thickener is discharged into the circulating water pool. The magnetic material after magnetic separation is discharged into the comprehensive recovery bin as raw material for subsequent comprehensive recovery process, and is reserved.

[0152] Step 3: Iron concentrate recovery: The magnetic material in the comprehensive recovery bin is fed into a wet first ball mill by a disc feeder, and a coarse material with a grinding fineness of-200 mesh accounting for 45% is obtained. The ground ore slurry is subjected to two-stage wet magnetic separation after water is added for slurry preparation, 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 two-stage 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 a box filter in the silver concentrate recovery process for filtration, and the recovery of silver concentrate is carried out together. The magnetic tailings after magnetic separation are reserved.

[0153] Step 4: Carbon concentrate powder recovery: The magnetic tailings after magnetic separation are fed into a wet second ball mill for grinding, and a fine material with a grinding fineness of-200 mesh accounting for 85% is obtained. The fine material is pumped to a hydrocyclone, and the overflow of the hydrocyclone is subjected to a carbon flotation process after slurry preparation in a stirring barrel. One-stage roughing and one-stage cleaning are carried out in turn. During one-stage roughing, the amount of kerosene is 400g / t, and the amount of 2# oil is 200g / t. Carbon is recovered, and the carbon concentrate obtained after cleaning is pumped to a second thickener for gravity settling and concentration. The bottom slurry is pumped to a buffer stirring barrel, and is filtered by a ceramic filter after slurry preparation to obtain carbon concentrate powder. The overflow of the second thickener is discharged into the circulating water pool. The carbon concentrate powder tailings after cleaning are reserved. The sand produced in the hydrocyclone is returned to the first ball mill to form a non-magnetic material grinding closed circuit.

[0154] Step 5: Silver concentrate recovery: The carbon concentrate powder tailings after scavenging are subjected to a silver flotation process after slurry preparation in a lifting stirring barrel. One-stage roughing, two-stage cleaning and two-stage scavenging are carried out in turn. During one-stage roughing, the amount of butyl xanthate is 400g / t, and the amount of 2# oil is 200g / t. During first-stage scavenging, the amount of butyl xanthate is 200g / t, and the amount of 2# oil is 100g / t. During second-stage scavenging, the amount of butyl xanthate is 100g / t, and the amount of 2# oil is 50g / t. The slurry obtained after scavenging is pumped to a third thickener for gravity settling and concentration. The bottom slurry is pumped to a buffer stirring barrel, and is filtered by a box filter after slurry preparation to obtain silver concentrate. The overflow of the third thickener is discharged into the circulating water pool. The silver concentrate tailings after scavenging are reserved.

[0155] Step 6: tailings recovery: the tailings after the sweep election silver concentrate are subjected to strong magnetic separation, and the concentrate after the strong magnetic separation is pumped to the belt vacuum filter in the iron concentrate recovery process for filtration to obtain the iron concentrate; the slag slurry after the strong magnetic separation is pumped to the fourth thickener, and after the gravity sedimentation and concentration of the thickener, the bottom slag is pumped to the buffer mixing barrel, filtered through the ceramic filter after the slurry adjustment to obtain the tailings. The overflow of the fourth thickener enters the circulating water pool.

[0156] Comparative Example 2

[0157] Referring to Figure 1 and Figure 2 , the embodiment provides a method for high-value comprehensive utilization of zinc smelting kiln slag, comprising the following steps:

[0158] Step 1: zinc smelting kiln slag pretreatment: the raw material zinc smelting kiln slag is classified by a grizzly screen, the grizzly screen has a hole diameter of 150 mm, the undersize of the grizzly screen enters a chute and then a belt conveyor, the oversize of the grizzly screen enters a first jaw crusher, the crushed kiln slag enters the belt conveyor, a belt de-ironer is suspended above the belt conveyor to remove iron blocks, and the kiln slag after the removal of the iron blocks is conveyed by the belt conveyor to a linear vibrating screen, the linear vibrating screen has a hole diameter of 20 mm*20 mm, the oversize of the linear vibrating screen enters a second jaw crusher to be crushed into crushed materials with a particle size of less than 2 cm, and the crushed kiln slag and the kiln slag undersize of the linear vibrating screen enter the belt conveyor and then a powder bin for standby.

[0159] In order to prevent dust from being generated in the process of crushing the kiln slag, the grizzly screen is washed with water at the same time, on the one hand, the kiln slag is kept moist to prevent dust from being generated in the crushing process, and on the other hand, the fine particles attached to the large-particle kiln slag are washed down for better separation, so that the iron blocks do not take away part of the fine particles of carbon, thereby reducing the carbon recovery rate.

[0160] Step 2: particle coke recovery: the crushed kiln slag with a particle size of less than 2 cm is subjected to two-stage wet magnetic separation, the first-stage magnetic separation has a strength of 5000Gs, and the second-stage magnetic separation has a strength of 7500Gs, the non-magnetic materials after the two-stage magnetic separation are screened by a jig and a spiral classifier in sequence to obtain the particle coke. The water discharged from the jig and the spiral classifier enters a first thickener, the bottom slag is subjected to water control again to obtain the particle coke again after the gravity sedimentation and concentration of the first thickener, and the overflow of the first thickener enters a circulating water pool. The magnetic materials after the magnetic separation enter a comprehensive recovery bin as raw materials for a subsequent comprehensive recovery process for standby.

[0161] Step 3: Iron concentrate recovery: the magnetic material in the comprehensive recovery bin is fed into a wet first ball mill for grinding, to obtain coarse material with a grinding fineness of 50% passing 200 mesh. After ball grinding, the slurry is thickened by adding water and then subjected to two-stage wet magnetic separation, with a first-stage magnetic intensity of 2500Gs and a second-stage magnetic intensity of 3500Gs. The magnetic concentrate (high-silver iron concentrate slurry) after the two-stage magnetic separation is pumped to a belt vacuum filter for filtration, to obtain the iron concentrate. The filtrate obtained by filtration and the slurry after washing the filter cloth are pumped to the silver concentrate recovery process for filtration in a chamber filter, to recover the silver concentrate together. The magnetic tailings after the magnetic separation are reserved.

[0162] Step 4: Carbon concentrate recovery: the magnetic tailings after the magnetic separation are fed into a wet second ball mill for grinding, to obtain fine material with a grinding fineness of 80% passing 200 mesh. The fine material is pumped to a hydrocyclone, and the overflow of the hydrocyclone is subjected to carbon flotation after thickening in a stirring barrel, to sequentially perform one-stage roughing and one-stage cleaning. In the one-stage roughing, 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 the cleaning is pumped to a second thickener, which is subjected to gravity sedimentation and thickening. The bottom sludge is pumped to a buffer stirring barrel, which is thickened after stirring, and then filtered by a ceramic filter to obtain the carbon concentrate. The overflow of the second thickener is discharged into a circulating water pool. The carbon concentrate tailings after the cleaning are reserved. The sand produced in the hydrocyclone is returned to the first ball mill to form a non-magnetic material grinding closed circuit.

[0163] Step 5: Silver concentrate recovery: the carbon concentrate tailings after the cleaning are subjected to silver flotation after thickening in a lifting stirring barrel. The process sequentially includes one-stage roughing, two-stage cleaning and two-stage scavenging. In the one-stage roughing, the amount of butyl xanthate is 600g / t, and the amount of 2# oil is 200g / t. In the first-stage scavenging, the amount of butyl xanthate is 300g / t, and the amount of 2# oil is 100g / t. In the second-stage scavenging, the amount of butyl xanthate is 150g / t, and the amount of 2# oil is 50g / t. The slurry obtained after the scavenging is pumped to a third thickener, which is subjected to gravity sedimentation and thickening. The bottom sludge is pumped to a buffer stirring barrel, which is thickened after stirring, and then filtered by a chamber filter to obtain the silver concentrate. The overflow of the third thickener is discharged into a circulating water pool. The silver concentrate tailings after the scavenging are reserved.

[0164] Step 6: Tailings recovery: the silver concentrate tailings after the scavenging are filtered by a ceramic filter to obtain the tailings.

[0165] Preferably, in the present embodiment, the silver concentrate tailings after the scavenging are subjected to high-intensity magnetic separation. The concentrate after the high-intensity magnetic separation is pumped to a belt filter in the iron concentrate recovery process for filtration, to obtain the iron concentrate. The slurry after the high-intensity magnetic separation is pumped to a thickener, which is subjected to gravity sedimentation and thickening. The bottom sludge is filtered by a ceramic filter to obtain the tailings.

[0166] As an exemplary illustration, specifically:

[0167] The scanned silver concentrate tailings are subjected to high-intensity magnetic separation, and the concentrate after high-intensity magnetic separation is pumped to a belt vacuum filter in the iron concentrate recovery process for filtration to obtain iron concentrate; the slag slurry after high-intensity magnetic separation is pumped to the fourth thickener by a slag slurry pump, and after gravity settling and thickening in the thickener, the bottom slag is pumped to a buffer mixing tank, filtered by a ceramic filter after slurry adjustment, to obtain tailings. The overflow of the fourth thickener enters the circulating water pool.

[0168] Example 4: Application

[0169] In this example, the zinc smelting volatilization kiln slag from Zhuzhou Nonferrous Zinc Oxide Plant was selected as the experimental ore, and the mineral composition elements of the zinc smelting kiln slag of the experimental ore are shown in Table 1.

[0170] Table 1: Element analysis of raw materials (%)

[0171]

[0172] The experimental ore was subjected to mineral processing by using the experimental methods of Examples 1, 2, 3 and Comparative Examples 1 and 2 above to recover carbon and valuable metals therefrom, and the results are shown in Table 2.

[0173] Table 2

[0174]

[0175] As can be seen from the data in Table 2, the magnetic separation intensity, grinding fineness and reagent dosage of the kiln slag beneficiation directly affect the yield and grade of the product (experimental examples 1, 2, 3 and comparative examples 1, 2), too low magnetic separation intensity can improve the yield but the product grade is too low to meet the actual recycling requirements, on the contrary, too high magnetic separation intensity will reduce the yield, both of which will reduce the recovery rate, which shows that moderate magnetic separation intensity can effectively ensure the grade and recovery rate of the product; the grinding fineness has little effect on the overall recovery rate when selecting iron, but has certain influence on the enrichment degree of silver (experimental examples 1, 2, 3 and comparative example 2), when the grinding fineness of-200 mesh is controlled at 35% to 45%, the silver content in the iron concentrate is >100 g / t, and <100 g / t when the grinding fineness is lower than 35% or higher than 45%, according to the pricing method of iron concentrate on the market, the silver content in the iron concentrate is not included in the pricing range when it is <100 g / t, which will cause a significant decline in the economic value of the product, so 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 beneficiation (experimental examples 1, 2, 3); in addition, with the increase of the reagent dosage for floating carbon and silver, the yield and recovery rate of carbon and silver will increase, but with the increase of the dosage, the recovery rate gradually stabilizes and no longer increases significantly 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.

[0176] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present application and not to limit it, although the present application has been described in detail with reference to examples, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the present application, which should be covered in the scope of the claims of the present application.

Claims

1. A method for the high-value comprehensive utilization of zinc smelting kiln slag, characterized in that, include: Zinc smelting kiln slag pretreatment: The zinc smelting kiln slag is screened and crushed into slag fragments with a particle size of less than 2cm for later use. Particle coke recovery: Crushed kiln slag with a particle size of less than 2cm is subjected to two-stage wet magnetic separation. The non-magnetic material after magnetic separation is then screened by a jig and a spiral classifier to remove the particle coke. The magnetic material after magnetic separation is used as raw material for subsequent comprehensive recycling processes and is reserved for later use. Iron concentrate recovery: The magnetic material after magnetic separation is passed through a wet ball mill to obtain coarse material with a grinding fineness of -200 mesh accounting for 35% to 45%; the obtained coarse material is passed through a two-stage wet magnetic separation, and the magnetic concentrate after magnetic separation is filtered through a belt filter to obtain iron concentrate; the magnetic tailings after magnetic separation are reserved for later use. Carbon concentrate recovery: The magnetic tailings 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 75% to 85%; the fine material is then subjected to a first-stage roughing and a first-stage cleaning process, with the addition of collectors and frothers to recover carbon; the carbon concentrate obtained after cleaning is filtered by a ceramic filter to obtain carbon concentrate; the carbon concentrate tailings after cleaning are reserved for later use. Silver concentrate recovery: The refined carbon concentrate tailings are sequentially passed through a roughing stage, two cleaning stages, and two scavenging stages. Collectors and frothers are added to recover silver. The slurry obtained after scavenging is filtered by a chamber filter to obtain silver concentrate. The silver concentrate tailings after scavenging are set aside for later use. Tailings recovery: The tailings of the scavenged silver concentrate are filtered through a ceramic filter to obtain tailings; The tailings recovery process includes: the silver concentrate tailings after scavenging are subjected to strong magnetic separation, 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 slurry after strong magnetic separation is sent to a thickener, and after gravity settling and concentration in the thickener, the bottom slag is filtered by a ceramic filter to obtain tailings. In the granular coke recovery process, the kiln slag fragments are subjected to two stages of wet magnetic separation, with the first stage having a magnetic separation intensity of 3000-4000 Gs and the second stage having a magnetic separation intensity of 5000-6000 Gs; in the iron concentrate recovery process, the obtained coarse material is subjected to two stages of wet magnetic separation, with the first stage having a magnetic separation intensity of 1600-2000 Gs and the second stage having a magnetic separation intensity of 2200-2500 Gs; In the silver concentrate recovery process, the collector is butyl xanthate and the frother is No. 2 oil; In the silver concentrate recovery process, during the first roughing stage, the dosage of xanthate is 400-600 g / t, and the dosage of No. 2 oil is 150-300 g / t; during the first scavenging stage, the dosage of xanthate is 200-300 g / t, and the dosage of No. 2 oil is 75-150 g / t; during the second scavenging stage, the dosage of xanthate is 100-150 g / t, and the dosage of No. 2 oil is 50-75 g / t.

2. The method for high-value comprehensive utilization of zinc smelting kiln 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 settling and concentration in the thickener, the bottom residue is treated with water control to obtain pellet coke again.

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

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

5. The method for high-value comprehensive utilization of zinc smelting kiln slag according to any one of claims 1-4, characterized in that, In the carbon concentrate recovery process, the collector is kerosene and the foaming agent is No. 2 oil.

6. The method for high-value comprehensive utilization of zinc smelting kiln slag according to claim 5, characterized in that, In the carbon concentrate recovery process, during the first stage of roughing, the amount of kerosene used is 600-1000 g / t, and the amount of No. 2 oil used is 200-400 g / t.

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