CN213803930U - System for comprehensive treatment of zinc dross - Google Patents

Abstract

The utility model discloses a system for comprehensive processing zinc dross, wherein, the system for comprehensive processing zinc dross includes: screening plant, ball mill, fly ash separation unit, acid dip pickle, first solid-liquid separation equipment and evaporation crystallization device. The system is utilized to comprehensively treat the zinc dross, so that each material component in the zinc dross is thoroughly separated, the zinc recovery rate is obviously improved (the zinc recovery rate is up to more than 99%), and the process flow is simple, the operation is simple and convenient, the energy consumption is low, and the environment is friendly; in addition, the impurity element chlorine in the zinc dross is well opened, so that the adverse effect on a zinc hydrometallurgy system is avoided, and the zinc chloride obtained by comprehensive treatment can be sold as a product, so that the zinc hydrometallurgy method has good economic benefit and environmental emission reduction benefit.

Description

System for comprehensive treatment of zinc dross

Technical Field

The utility model belongs to the metallurgical field, concretely relates to system for comprehensive treatment zinc dross.

Background

In the casting process of zinc hydrometallurgy, because the temperature is high, the zinc liquid on the surface is easily oxidized by air, a layer of zinc oxide scum is generated on the surface of a zinc molten pool, and the generation rate of the scum is 3-5%. In the process of zinc casting, in order to not influence the production, part of scum needs to be periodically taken out, and a certain thickness of the scum layer is kept. Before slag skimming, solid ammonium chloride is generally needed to be scattered, and the solid ammonium chloride is fully stirred to react with zinc oxide to generate zinc chloride, because the melting point (about 283 ℃) of the zinc chloride is lower than the melting point (419.5 ℃) of the zinc, the zinc oxide film in the scum is damaged by the reaction, so that zinc liquid included and wrapped in the scum layer flows out, the zinc content of the scum is reduced, and the direct yield of the zinc is improved. Therefore, the zinc dross is a mixture of zinc oxide, zinc chloride and metal zinc, contains more than 80 percent of zinc and has higher recycling value. Because zinc dross contains part of zinc chloride, the chlorine content in the dross is 3% -5%, and the open circuit of impurity chlorine is needed while comprehensively recovering zinc, so as to reduce the influence on a zinc hydrometallurgy system.

The patent application with application number 20111037769.6 discloses a method for extracting metallic zinc powder with different purposes from zinc dross, which mainly comprises the steps of repeatedly grinding the dross by a ball mill, and then screening and separating the zinc powder and zinc ash with different particle sizes, wherein the process has three disadvantages: firstly, the massive zinc is not easy to be levigated, the grinding efficiency is low, and the energy consumption is increased by repeated grinding; secondly, the zinc powder and the zinc ash are not completely separated, and the purity of the zinc powder is low; and thirdly, the separation of zinc oxide and zinc chloride is not realized, zinc ash contains chlorine, the zinc ash returns to the fluidized bed furnace for material preparation, the chlorine content of flue gas is high, equipment is corroded, and the method is not environment-friendly.

Thus, there is a need for improvement in the art of treating zinc dross.

SUMMERY OF THE UTILITY MODEL

The present invention aims at solving at least one of the technical problems in the related art to a certain extent. Therefore, an object of the utility model is to provide a system for integrated processing zinc dross uses this system to separate each material composition in the zinc dross, and its separation effect is good, is showing the rate of recovery that has improved zinc, and is easy and simple to handle, environment friendly, and impurity chlorine element has obtained good opening a way, has realized the utilization of resources.

In one aspect of the present invention, the utility model provides a system for comprehensive treatment of zinc dross. According to the utility model discloses an embodiment, the system of integrated processing zinc dross includes:

a screening device having a zinc dross inlet, a bulk zinc outlet, and an undersize outlet;

the ball mill is provided with an undersize inlet, a zinc particle outlet and a zinc dust outlet, and the undersize inlet is connected with the undersize outlet;

the dust separation unit is provided with a zinc dust inlet, a zinc dust outlet and a zinc dust outlet, and the zinc dust inlet is connected with the zinc dust outlet;

the pickling device is provided with a zinc ash inlet, a hydrochloric acid washing liquid inlet and a pickled liquid outlet, and the zinc ash inlet is connected with the zinc ash outlet;

the first solid-liquid separation device is provided with a pickling waste liquid inlet, a pickling filtrate outlet and a pickling residue outlet, and the pickling waste liquid inlet is connected with the pickling waste liquid outlet;

the evaporative crystallization device is provided with an acid washing filtrate inlet, an evaporated water outlet and a zinc chloride crystal outlet, and the acid washing filtrate inlet is connected with the acid washing filtrate outlet.

According to the utility model discloses a system of integrated processing zinc dross, carry out preliminary screening through supplying zinc dross to screening plant, the separation obtains cubic zinc and contains the undersize of zinc particle and zinc ash powder, thereby can at first separate cubic zinc from zinc dross, the undersize that contains zinc particle and zinc ash powder is supplied to the ball mill under negative pressure environment and is ground, the separation obtains zinc particle and zinc dust, thereby can continue to separate zinc particle from zinc dross, then zinc dust is supplied to the ash separation unit, the separation obtains zinc powder and zinc dust, and supply zinc dust to the pickling plant and contact with hydrochloric acid lotion and carry out the pickling, the pickling of pickling back liquid that obtains is supplied to first solid-liquid separation equipment and carries out first solid-liquid separation, obtain pickling filtrating and pickling filtrating, supply the pickling filtrating to evaporating crystallization device at last and handle, thereby obtaining evaporated water and zinc chloride crystals. The system is utilized to comprehensively treat the zinc dross, so that each material component in the zinc dross is thoroughly separated, the zinc recovery rate is obviously improved (the zinc recovery rate is up to more than 99%), and the process flow is simple, the operation is simple and convenient, the energy consumption is low, and the environment is friendly; in addition, the impurity element chlorine in the zinc dross is well opened, the adverse effect on a zinc hydrometallurgy system is avoided, and the zinc chloride obtained by evaporating and crystallizing the pickling filtrate can be sold as a product, so that the method has good economic benefit and environmental emission reduction benefit.

In addition, the system for comprehensively treating zinc dross according to the embodiment of the present invention can also have the following additional technical features:

preferably, the dust and dust separating unit comprises a cyclone dust collector and a bag-type dust collector which are connected in sequence. Therefore, after the zinc dust discharged from the ball mill is supplied to the dust separating unit, the zinc powder is collected in the cyclone dust collector under the action of the cyclone dust collector, and the lighter zinc dust finally enters the bag-type dust collector, so that the separation of the zinc powder and the zinc dust is realized.

Preferably, the above system further comprises: the forming device is provided with a block zinc inlet, a zinc particle inlet and a pellet outlet, the block zinc inlet is connected with the block zinc outlet, and the zinc particle inlet is connected with the zinc particle outlet. Therefore, the blocky zinc and the zinc particles can be respectively briquetted and molded and then return to the zinc melting furnace, thereby improving the recovery rate of zinc.

Preferably, the above system further comprises: the washing device is provided with a pickling residue inlet, a washing liquid inlet and a washed liquid outlet, and the pickling residue inlet is connected with the pickling residue outlet; and the second solid-liquid separation device is provided with a washed liquid inlet, a washed filtrate outlet and a washed residue outlet, the washed liquid inlet is connected with the washed liquid outlet, and the washed filtrate outlet is connected with the hydrochloric acid washing liquid inlet. Therefore, the acid washing filter residue is washed by water, the obtained water washing filter residue is supplied to a zinc leaching process of a wet system as a zinc-containing raw material, so that the zinc recovery rate is improved, the liquid after washing is subjected to second solid-liquid separation, and the obtained water washing filtrate is returned to the acid washing process, so that the production cost is saved.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic structural view of a system for integrated processing of zinc dross according to an embodiment of the present invention;

fig. 2 is a schematic structural view of a system for integrated processing of zinc dross according to still another embodiment of the present invention;

fig. 3 is a schematic structural view of a system for integrated processing of zinc dross according to still another embodiment of the present invention;

fig. 4 is a schematic structural view of a system for integrated processing of zinc dross according to still another embodiment of the present invention;

fig. 5 is a schematic flow chart of a method for comprehensively treating zinc dross by using the system according to an embodiment of the invention;

fig. 6 is a schematic flow chart illustrating a method for comprehensively treating zinc dross by using the system according to still another embodiment of the present invention;

fig. 7 is a schematic view of a process flow for comprehensive treatment of zinc dross using the system according to an embodiment of the invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present invention, and should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In one aspect of the present invention, the utility model provides a system for comprehensive treatment of zinc dross. According to an embodiment of the present invention, referring to fig. 1, the system includes: the device comprises a screening device 100, a ball mill 200, a dust separation unit 300, an acid washing device 400, a first solid-liquid separation device 500 and an evaporative crystallization device 600.

According to the utility model discloses an embodiment, screening plant 100 has zinc dross entry 11, cubic zinc export 12 and undersize export 13, and is suitable for and supplies zinc dross to screening plant 100 in and carries out the screening processing, and the separation obtains cubic zinc and contains the undersize of zinc particle and zinc dust. Specifically, the separation principle of the screening device 100 is as follows: by utilizing the relative movement of the bulk material and the screen surface, zinc particles and zinc dust smaller than the size of the screen hole penetrate through the screen hole, and the blocky zinc larger than the size of the screen hole is continuously discharged from the blocky zinc outlet, so that the blocky zinc is firstly separated from the zinc dross. It should be noted that the specific type of the sieving device 100 can be selected by those skilled in the art according to actual needs, as long as the above-mentioned functions can be achieved.

According to the utility model discloses an embodiment, ball mill 200 has subsieve inlet 21, zinc particle export 22 and zinc dust export 23, and subsieve inlet 21 links to each other with subsieve outlet 13, and is suitable for and carries out the ball-milling under suitable negative pressure environment with zinc particle and zinc dust supply to ball mill 200, carries out the selection by winnowing separation according to the quality difference of zinc particle and zinc dust, and the separation obtains zinc particle and zinc dust, and discharges the zinc particle from the zinc particle export to make the zinc particle separate out from the zinc dross. Preferably, the above-mentioned suitable negative pressure environment is achieved by adjusting the frequency of a centrifugal fan (not shown). It should be noted that, the specific types of the ball mill 200 and the centrifugal fan can be selected by those skilled in the art according to actual needs, as long as the above functions can be achieved.

According to the utility model discloses an embodiment, the dust separation unit 300 has zinc dust entry 31, zinc dust export 32 and zinc dust export 33, and zinc dust entry 31 links to each other with zinc dust export 23, and is suitable for supplying zinc dust to dust separation unit 300, and the separation obtains zinc powder and zinc dust. It should be noted that the specific type of the dust separating unit 300 can be selected by those skilled in the art according to actual needs, as long as the above-mentioned functions can be achieved.

Further, referring to fig. 2, the dust and dust separating unit 300 includes a cyclone 301 and a bag-type dust collector 302 connected in sequence, under the action of the cyclone 301, zinc dust is collected in the cyclone 301, and the lighter zinc dust finally enters the bag-type dust collector 302. It should be noted that, a person skilled in the art may select specific types of the cyclone dust collector 301 and the bag-type dust collector 302 according to actual needs, as long as the above functions are achieved.

According to the utility model discloses an embodiment, acid dip pickle 400 has zinc ash entry 41, hydrochloric acid lotion entry 42 and the liquid export 43 after the pickling, and zinc ash entry 41 links to each other with zinc ash export 33, and is suitable for to supply with zinc ash to acid dip pickle 400 and hydrochloric acid lotion contact and carry out the pickling, obtains the washing liquid after the pickling. The inventor finds that zinc ash mainly contains zinc oxide and impurity element chlorine mainly contains Zn₅(OH)₈Cl₂·2H₂O is present in the form of almost all Zn₅(OH)₈Cl₂·2H₂O and part of zinc oxide can react with hydrochloric acid washing liquor to generate zinc chloride which enters a liquid phase, so that an impurity element chlorine is well opened, and adverse effects on a wet zinc smelting system are avoided. The specific type of pickling device 400 may be selected by those skilled in the art according to actual needs, as long as the above-described function is achieved. Preferably, the pH value of the hydrochloric acid washing liquid is 1.0-4.5; the solid-liquid ratio of the zinc ash to the hydrochloric acid washing liquid is 1 g: (3-10) mL; the temperature of the hydrochloric acid washing liquid is 50 toThe pickling time is 0.5-5 h at 80 ℃.

According to the utility model discloses an embodiment, first solid-liquid separation equipment 500 has pickling back liquid entry 51, pickling filtrating export 53 and pickling filter residue export 52, and pickling back liquid entry 51 links to each other with pickling back liquid export 43, and is suitable for and supplies to first solid-liquid separation equipment 500 with pickling back liquid and carry out solid-liquid separation, obtains pickling filtrating and pickling filter residue. It should be noted that, a person skilled in the art may select a specific type of the first solid-liquid separation device 500 according to actual needs, as long as the above-described functions can be achieved.

According to the utility model discloses an embodiment, evaporative crystallization device 600 has pickling filtrating entry 61, evaporating water export 63 and zinc chloride crystal export 62, and pickling filtrating entry 61 links to each other with pickling filtrating export 53, and is suitable for and supplies pickling filtrating to evaporating crystallization device 600 in to evaporate, concentrate, dry, obtains evaporating water and zinc chloride crystal. It should be noted that, the specific type of the evaporative crystallization apparatus 600 can be selected by those skilled in the art according to actual needs, as long as the above-mentioned functions can be achieved.

The inventors found that by supplying zinc dross to a screening device for primary screening, lump zinc and undersize containing zinc particles and zinc ash powder are separated, so that the zinc particles can be continuously separated from the zinc dross by firstly separating the zinc blocks from the zinc dross, feeding undersize containing the zinc particles and the zinc ash powder to a ball mill for ball milling under the negative pressure environment, separating the zinc particles and the zinc ash powder, and then the zinc dust is supplied to a dust separation unit, zinc dust and zinc dust are obtained through separation, the zinc dust is supplied to an acid washing device to be in contact with hydrochloric acid washing liquor for acid washing, the obtained acid washing liquor is supplied to a first solid-liquid separation device for first solid-liquid separation, acid washing filtrate and acid washing filter residue are obtained, and finally the acid washing filtrate is supplied to an evaporation crystallization device for treatment, so that evaporation water and zinc chloride crystals are obtained. The system is utilized to comprehensively treat the zinc dross, so that each material component in the zinc dross is thoroughly separated, the zinc recovery rate is obviously improved (the zinc recovery rate is up to more than 99%), and the process flow is simple, the operation is simple and convenient, the energy consumption is low, and the environment is friendly; in addition, the impurity element chlorine in the zinc dross is well opened, the adverse effect on a zinc hydrometallurgy system is avoided, and the zinc chloride obtained by evaporating and crystallizing the pickling filtrate can be sold as a product, so that the method has good economic benefit and environmental emission reduction benefit.

Further, referring to fig. 3 to 4, the system for comprehensively treating zinc dross further includes a forming device 700, a water washing device 800, and a second solid-liquid separating device 900.

According to the embodiment of the utility model, referring to fig. 3, forming device 700 has cubic zinc entry 71, zinc particle entry 72 and pelletizing export 73, and cubic zinc entry 71 links to each other with cubic zinc export 12, and zinc particle entry 72 links to each other with zinc particle export 22, and is suitable for and returns zinc to melt the zinc stove with cubic zinc and zinc particle supply to forming device 700 respectively and press after the briquetting, retrieves zinc to the zinc rate of recovery has been improved. It should be noted that, a person skilled in the art can select a specific type of the molding apparatus 700 according to actual needs, as long as the above-mentioned functions can be achieved.

According to the embodiment of the utility model, referring to fig. 4, washing device 800 has pickling filter residue entry 81, washing liquid entry 82 and washing back liquid export 83, pickling filter residue entry 81 with pickling filter residue export 52 links to each other, and is suitable for supplying with the pickling filter residue to washing device 800 and carries out the washing, and the washing filter residue is supplied with the zinc leaching process to wet system as zinciferous raw materials to zinc rate of recovery has been improved. It should be noted that, a person skilled in the art can select a specific type of the water washing apparatus 800 according to actual needs, as long as the above-mentioned functions can be achieved. Preferably, the temperature of the washing liquid is 50-80 ℃, and the washing time is 0.5-5 h.

According to the embodiment of the utility model, referring to fig. 4, second solid-liquid separation equipment 900 has washing back liquid entry 91, washing filtrate export 93 and washing filter residue export 92, and washing back liquid entry 91 links to each other with washing back liquid export 83, and washing filtrate export 93 links to each other with hydrochloric acid lotion entry 42, and is suitable for and carries out second solid-liquid separation in supplying to second solid-liquid separation equipment 900 with washing back liquid to the washing filtrating that will obtain returns the pickling process, thereby has practiced thrift manufacturing cost. It should be noted that, a person skilled in the art may select a specific type of the second solid-liquid separation device 900 according to actual needs, as long as the above-described functions can be achieved.

For ease of understanding, the method of performing integrated processing of zinc dross using the above system is described below. According to an embodiment of the present invention, referring to fig. 5, the method includes:

s100: feeding zinc dross to a screening device for screening

In this step, the zinc dross is supplied to a sieving device and sieved, whereby the zinc cake and undersize containing zinc particles and zinc dust can be separated. Specifically, the separation principle of the screening device is as follows: by utilizing the relative movement of the bulk material and the screen surface, zinc particles and zinc dust smaller than the size of the screen hole penetrate through the screen hole, and the blocky zinc larger than the size of the screen hole is continuously discharged from the blocky zinc outlet, so that the blocky zinc is firstly separated from the zinc dross.

S200: under the negative pressure environment, undersize containing zinc particles and zinc dust is supplied to a ball mill for ball milling

In this step, undersize containing zinc particles and zinc dust is supplied to a ball mill and ball-milled in a suitable negative pressure environment, air separation is performed according to the mass difference between the zinc particles and the zinc dust, the zinc particles and the zinc dust are separated, and the zinc particles are discharged from a zinc particle outlet, so that the zinc particles are separated from zinc dross. Preferably, the above-mentioned suitable negative pressure environment is achieved by adjusting the frequency of the centrifugal fan.

S300: supplying the zinc dust to a dust separation unit

In this step, zinc dust and zinc dust can be separated by supplying the zinc dust to a dust separation unit. Specifically, the dust-dust separation unit comprises a cyclone dust collector and a bag-type dust collector which are connected in sequence, zinc powder is collected in the cyclone dust collector under the action of the cyclone dust collector, and the lighter zinc dust finally enters the bag-type dust collector. Further, zinc powder is supplied as an auxiliary material to the purification process of the primary system.

S400: zinc ash is supplied to a pickling device to be contacted with hydrochloric acid washing liquid

In this step, zinc ash is supplied to an acid washing apparatus and brought into contact with a hydrochloric acid washing solution to be washed with acid, whereby a washed solution after acid washing can be obtained. The inventor finds that zinc ash mainly contains zinc oxide and impurity element chlorine mainly contains Zn₅(OH)₈Cl₂·2H₂O is present in the form of almost all Zn₅(OH)₈Cl₂·2H₂O and part of zinc oxide can react with hydrochloric acid washing liquor to generate zinc chloride which enters a liquid phase, so that an impurity element chlorine is well opened, and adverse effects on a wet zinc smelting system are avoided.

Further, the pH value of the hydrochloric acid washing liquid is 1.0-4.5, and preferably 3.5-4.5. The inventors found that the higher the acidity of the hydrochloric acid washing liquid, the higher the removal rate of chlorine from the zinc ash, but too high acidity may dissolve a large amount of zinc oxide, lowering the recovery rate of zinc, and also corrode equipment, causing crystallization and clogging of pipes.

Further, the solid-to-liquid ratio of the zinc ash to the hydrochloric acid washing liquid is 1 g: (3-10) mL, preferably the solid-to-liquid ratio is 1 g: (3-4) mL. The inventor finds that if the solid-to-liquid ratio is too large, the zinc ash cannot be fully contacted with hydrochloric acid washing liquor, so that more impurity elements chlorine still remaining in the zinc ash cannot be dissolved into a liquid phase, the zinc ash contains chlorine, the zinc ash returns to a fluidized bed furnace for material preparation, the chlorine content of flue gas is high, equipment is corroded, and the method is not environment-friendly; if the solid-liquid ratio is too small, a large load is imposed on the subsequent first solid-liquid separation and evaporative crystallization processes, and the production cost is increased.

Further, the temperature of the hydrochloric acid washing liquid is 50-80 ℃, preferably 60-70 ℃, and the acid washing time is 0.5-5 hours, preferably 2-3 hours. The inventors found that if the temperature of the hydrochloric acid washing solution is too low, the pickling efficiency is reduced; and if the temperature of the hydrochloric acid washing liquid is too high, the energy consumption is increased. If the pickling time is too short, the zinc ash cannot be sufficiently pickled, so that more impurity element chlorine still remaining in the zinc ash cannot be dissolved and enters a liquid phase, the zinc ash contains chlorine, the zinc ash returns to a fluidized bed furnace for material preparation, the chlorine content of flue gas is high, equipment is corroded, and the method is not environment-friendly; if the pickling time is too long, the production efficiency is lowered.

S500: the acid-washed liquid is supplied to a first solid-liquid separation device for treatment

In this step, the acid-washed liquid is supplied to the first solid-liquid separation device to be subjected to solid-liquid separation, thereby obtaining an acid-washed filtrate and acid-washed residue.

S600: the acid-washing filtrate is supplied to an evaporative crystallization device for treatment

In the step, the acid-washing filtrate is supplied to an evaporative crystallization device for evaporation, concentration and drying, so that evaporated water and zinc chloride crystals can be obtained, and the obtained zinc chloride can be sold as a product.

The inventors found that by supplying zinc dross to a screening device for primary screening, lump zinc and undersize containing zinc particles and zinc ash powder are separated, so that the zinc particles can be continuously separated from the zinc dross by firstly separating the zinc blocks from the zinc dross, feeding undersize containing the zinc particles and the zinc ash powder to a ball mill for ball milling under the negative pressure environment, separating the zinc particles and the zinc ash powder, and then the zinc dust is supplied to a dust separation unit, zinc dust and zinc dust are obtained through separation, the zinc dust is supplied to an acid washing device to be in contact with hydrochloric acid washing liquor for acid washing, the obtained acid washing liquor is supplied to a first solid-liquid separation device for first solid-liquid separation, acid washing filtrate and acid washing filter residue are obtained, and finally the acid washing filtrate is supplied to an evaporation crystallization device for treatment, so that evaporation water and zinc chloride crystals are obtained. The method is utilized to comprehensively treat the zinc dross, so that each material component in the zinc dross is thoroughly separated, the zinc recovery rate is obviously improved (the zinc recovery rate is up to more than 99%), and the method has the advantages of simple process flow, simple and convenient operation, low energy consumption and environmental friendliness; in addition, the impurity element chlorine in the zinc dross is well opened, the adverse effect on a zinc hydrometallurgy system is avoided, and the zinc chloride obtained by evaporating and crystallizing the pickling filtrate can be sold as a product, so that the method has good economic benefit and environmental emission reduction benefit.

Further, referring to fig. 6-7, the method for comprehensively treating zinc dross by using the system further comprises:

s700: supplying the zinc lumps obtained in step S100 and the zinc particles obtained in step S200 to a forming device, and supplying the pellets obtained to a zinc melting furnace to recover zinc

In the step, the blocky zinc obtained in the step S100 and the zinc particles obtained in the step S200 are supplied to a forming device, so that the blocky zinc or the zinc particles can be pressed into pellets, and the pellets are convenient to store and transport and reduce loss in the recycling process; and the obtained pellets are supplied to a zinc melting furnace to recover zinc, thereby improving the recovery rate of zinc.

S800: feeding the acid-washed filter residue into a water washing device to contact with water washing liquid

In this step, the acid-washed residue obtained in step S500 is supplied to a washing apparatus and is brought into contact with a washing liquid to be washed, thereby obtaining a washed liquid. The inventors found that the removal rate of chlorine can be further improved by the water washing process.

Further, the solid-to-liquid ratio of the acid washing filter residue to the water washing liquid is 1 g: (3-10) mL. Preferably 1 g: (6-8) mL. The inventor finds that if the solid-liquid ratio is too high, the washing is insufficient, the acid washing filter residue still contains a certain amount of impurity element chlorine, the impurity element chlorine is returned to the fluidized bed furnace for material preparation, the chlorine content of the flue gas is high, the equipment is corroded, and the environment is not friendly; if the solid-liquid ratio is too small, a large load is imposed on the subsequent second solid-liquid separation process, and the production cost is increased.

Further, the temperature of the water washing liquid is 50-80 ℃, preferably 50-60 ℃, and the water washing time is 0.5-5 hours, preferably 0.5-1 hour. The inventor finds that if the washing temperature is too low, the washing efficiency is reduced; and if the washing temperature is too high, the energy consumption is increased. If the washing time is too short, insufficient washing can be caused; if the washing time is too long, the production efficiency will be reduced.

S900: the water-washed residue is supplied to a zinc leaching step of a wet system as a zinc chloride raw material, the water-washed residue is supplied to a second solid-liquid separation device for treatment, the obtained water-washed filtrate is supplied to step S400 as a hydrochloric acid washing solution, and the obtained water-washed residue is supplied to a wet system

In the step, the water-washed liquid is supplied to a second solid-liquid separation device for treatment, so that water-washed filtrate and water-washed filter residue can be obtained through separation, and the obtained water-washed filtrate is supplied to the step S400 to be used as hydrochloric acid washing liquid, so that the water-washed filtrate is recycled, and the production cost is saved; the obtained water-washed filter residue is used as a zinc chloride raw material and is supplied to a zinc leaching process of a wet system, so that the zinc recovery rate is improved.

The solution of the present invention will be explained with reference to the following examples. It will be appreciated by those skilled in the art that the following examples are illustrative of the invention only and should not be taken as limiting the scope of the invention. The examples, where specific techniques or conditions are not indicated, are to be construed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.

Example 1

Step 1: taking 5000Kg of zinc dross (larger bulk zinc is picked out), naturally cooling to below 60 ℃, starting a centrifugal fan of a bag-type dust collector, and adjusting the air volume to 25000-30000 Nm³Uniformly and slowly adding zinc dross into a bin, and screening by using a linear vibrating screen to obtain blocky zinc and undersize containing zinc particles and zinc dust, wherein the blocky zinc enters a dross hopper from a chute;

step 2: feeding the undersize containing zinc particles and zinc dust to a ball mill for grinding, separating to obtain zinc particles and zinc dust, and discharging the zinc particles from a zinc particle outlet of the ball mill into a slag hopper;

and step 3: and discharging the zinc powder and the zinc ash from a zinc powder ash outlet of the ball mill, and allowing the zinc powder and the zinc ash to enter a dust collection pipeline, wherein the zinc powder enters a cyclone dust collector for collection due to mass difference, and the zinc ash enters a bag-type dust collector for collection. 265Kg of blocky zinc (the grain diameter is less than or equal to 50mm) is finally produced, 747Kg of zinc particles (the grain diameter is less than or equal to 50mm) is produced, 310Kg of zinc powder (the grain diameter is less than or equal to 80mm) and 3670Kg of zinc ash (the grain diameter is less than or equal to 100 mm) is produced;

and 4, step 4: supplying zinc ash to a pickling tank for slurrying and pickling, wherein the pH of a hydrochloric acid washing solution is 4.5, and the liquid-solid ratio is controlled to be 4m³The pickling temperature is 60 ℃, and pickling is carried out for 1h to obtain pickling cleaning solution;

and 5: carrying out filter pressing on the acid-washed liquid to obtain acid-washed filtrate and acid-washed filter residue, wherein the acid-washed filtrate contains 2.55g/L of zinc, 3.16g/L of chlorine and has pH of 5.0;

step 6: evaporating, concentrating and drying the acid-washing filtrate to produce 72.45Kg of zinc chloride with the purity of 99.65 percent;

and 7: supplying the blocky zinc obtained in the step (1) and the zinc particles obtained in the step (2) to a briquetting machine for briquetting and then supplying the briquetted zinc particles to a zinc melting furnace;

and 8: feeding the acid-washed filter residue obtained in the step (5) into a washing tank for slurrying and washing, wherein the liquid-solid ratio is controlled to be 4m³T, washing at the temperature of 60 ℃ for 1h to obtain a washing liquid;

and step 9: and (3) carrying out filter pressing on the washed solution to obtain washing filtrate and washing filter residue, returning the washing filtrate to the acid washing process, pulping the washing filter residue by using a leaching agent, and then entering a zinc leaching process of a wet system, wherein the chlorine content of the zinc oxide after washing is 0.0055%.

Example 2

Step 1: taking 5000Kg of zinc dross (larger bulk zinc is picked out), naturally cooling to below 60 ℃, starting a centrifugal fan of a bag-type dust collector, and adjusting the air volume to 25000-30000 Nm³Uniformly and slowly adding zinc dross into a bin, and screening by using a linear vibrating screen to obtain blocky zinc and undersize containing zinc particles and zinc dust, wherein the blocky zinc enters a dross hopper from a chute;

step 2: feeding the undersize containing zinc particles and zinc dust to a ball mill for grinding, separating to obtain zinc particles and zinc dust, and discharging the zinc particles from a zinc particle outlet of the ball mill into a slag hopper;

and step 3: and discharging the zinc powder and the zinc ash from a zinc powder ash outlet of the ball mill, and allowing the zinc powder and the zinc ash to enter a dust collection pipeline, wherein the zinc powder enters a cyclone dust collector for collection due to mass difference, and the zinc ash enters a bag-type dust collector for collection. The final product is 186Kg of zinc block (50mm < particle size ≦ 200mm), 803Kg of zinc particles (80 mesh < particle size ≦ 50mm), 361Kg of zinc powder (particle size ≦ 80mm), 3635Kg of zinc ash (particle size ≦ 100 mesh);

and 4, step 4: supplying zinc ash to a pickling tank for slurrying and pickling, wherein the pH of a hydrochloric acid washing solution is 3.5, and the liquid-solid ratio is controlled to be 3m³Acid washing is carried out for 0.5h at 70 ℃ to obtain acid washing liquid;

and 5: carrying out filter pressing on the acid-washed liquid to obtain acid-washed filtrate and acid-washed filter residue, wherein the acid-washed filtrate contains 4.85g/L of zinc, 6.24g/L of chlorine and has pH of 5.0;

step 6: evaporating, concentrating and drying the acid-washing filtrate to produce 101.17Kg of zinc chloride with the purity of 99.83 percent;

and 7: supplying the blocky zinc obtained in the step (1) and the zinc particles obtained in the step (2) to a briquetting machine for briquetting and then supplying the briquetted zinc particles to a zinc melting furnace;

and 8: feeding the acid-washed filter residue obtained in the step (5) into a washing tank for slurrying and washing, wherein the liquid-solid ratio is controlled to be 5m³T, washing at the temperature of 60 ℃ for 1h to obtain a washing liquid;

and step 9: and (3) carrying out filter pressing on the washed solution to obtain washing filtrate and washing filter residue, returning the washing filtrate to the acid washing process, pulping the washing filter residue by using a leaching agent, and then entering a zinc leaching process of a wet system, wherein the zinc oxide contains 0.0063% of chlorine after washing.

Example 3

Step 1: taking 5000Kg of zinc dross (larger bulk zinc is picked out), naturally cooling to below 60 ℃, starting a centrifugal fan of a bag-type dust collector, and adjusting the air volume to 25000-30000 Nm³Uniformly and slowly adding zinc dross into a bin, and screening by using a linear vibrating screen to obtain blocky zinc and undersize containing zinc particles and zinc dust, wherein the blocky zinc enters a dross hopper from a chute;

step 2: feeding the undersize containing zinc particles and zinc dust to a ball mill for grinding, separating to obtain zinc particles and zinc dust, and discharging the zinc particles from a zinc particle outlet of the ball mill into a slag hopper;

and step 3: and discharging the zinc powder and the zinc ash from a zinc powder ash outlet of the ball mill, and allowing the zinc powder and the zinc ash to enter a dust collection pipeline, wherein the zinc powder enters a cyclone dust collector for collection due to mass difference, and the zinc ash enters a bag-type dust collector for collection. Finally, 220Kg of blocky zinc (the grain diameter is less than or equal to 50mm) is produced, 659Kg of zinc particles (the grain diameter is less than or equal to 50mm) is produced, 382Kg of zinc powder (the grain diameter is less than or equal to 80mm) and 3728Kg of zinc ash (the grain diameter is less than or equal to 100 mesh) is produced;

and 4, step 4: supplying zinc ash to a pickling tank for slurrying and pickling, wherein the pH of a hydrochloric acid washing solution is 4.0, and the liquid-solid ratio is controlled to be 5m³Acid washing is carried out for 1.5h at 50 ℃ to obtain acid washing liquid;

and 5: carrying out filter pressing on the acid-washed liquid to obtain acid-washed filtrate and acid-washed filter residue, wherein the acid-washed filtrate contains 3.25g/L of zinc, 4.07g/L of chlorine and has pH of 5.0;

step 6: evaporating, concentrating and drying the acid-washing filtrate to produce 116.24Kg of zinc chloride with the purity of 99.70 percent;

and 7: supplying the blocky zinc obtained in the step (1) and the zinc particles obtained in the step (2) to a briquetting machine for briquetting and then supplying the briquetted zinc particles to a zinc melting furnace;

and 8: feeding the acid-washed filter residue obtained in the step (5) into a washing tank for slurrying and washing, wherein the liquid-solid ratio is controlled to be 4m³T, the water washing temperature is 65 ℃, and water washing is carried out for 0.5h to obtain water washing liquid;

and step 9: and (3) carrying out filter pressing on the washed solution to obtain washing filtrate and washing filter residue, returning the washing filtrate to the acid washing process, pulping the washing filter residue by using a leaching agent, and then entering a zinc leaching process of a wet system, wherein the chlorine content of the zinc oxide after washing is 0.0085%.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art without departing from the scope of the present invention.

Claims (4)

1. A system for integrated processing of zinc dross, comprising:

a screening device having a zinc dross inlet, a bulk zinc outlet, and an undersize outlet;

the ball mill is provided with an undersize inlet, a zinc particle outlet and a zinc dust outlet, and the undersize inlet is connected with the undersize outlet;

the dust separation unit is provided with a zinc dust inlet, a zinc dust outlet and a zinc dust outlet, and the zinc dust inlet is connected with the zinc dust outlet;

the pickling device is provided with a zinc ash inlet, a hydrochloric acid washing liquid inlet and a pickled liquid outlet, and the zinc ash inlet is connected with the zinc ash outlet;

the first solid-liquid separation device is provided with a pickling waste liquid inlet, a pickling filtrate outlet and a pickling residue outlet, and the pickling waste liquid inlet is connected with the pickling waste liquid outlet;

the evaporative crystallization device is provided with an acid washing filtrate inlet, an evaporated water outlet and a zinc chloride crystal outlet, and the acid washing filtrate inlet is connected with the acid washing filtrate outlet.

2. The system of claim 1, wherein the dust separating unit comprises a cyclone dust collector and a bag dust collector connected in series.

3. The system of claim 1 or 2, further comprising:

the forming device is provided with a block zinc inlet, a zinc particle inlet and a pellet outlet, the block zinc inlet is connected with the block zinc outlet, and the zinc particle inlet is connected with the zinc particle outlet.

4. The system of claim 1, further comprising:

the washing device is provided with a pickling residue inlet, a washing liquid inlet and a washed liquid outlet, and the pickling residue inlet is connected with the pickling residue outlet;

and the second solid-liquid separation device is provided with a washed liquid inlet, a washed filtrate outlet and a washed residue outlet, the washed liquid inlet is connected with the washed liquid outlet, and the washed filtrate outlet is connected with the hydrochloric acid washing liquid inlet.

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