System and method for regenerating KCl, NaCl and zinc ingot by utilizing metallurgical solid waste

Abstract

The invention provides a system and a method for regenerating KCl, NaCl and zinc ingots by utilizing metallurgical solid wastes. The system for regenerating the KCl, the NaCl and the zinc ingot by utilizing the metallurgical solid waste comprises a washing dechlorination and evaporative crystallization device, a rotary kiln defluorination and dechlorination device, a submerged arc furnace crude zinc extraction device and a rectifying tower refined zinc extraction device, the washing dechlorination and evaporative crystallization device comprises a sintering machine head ash washing dechlorination raw material device and a secondary zinc oxide powder washing dechlorination raw material device; the water-washing dechlorination and water-washing filter-pressing device is communicated with outlets of the sintering machine head ash water-washing dechlorination raw material device and the secondary zinc oxide powder water-washing dechlorination raw material device; and the evaporative crystallization device is communicated with an outlet of the water-washing dechlorination and water-washing filter-pressing device. According to the system provided by the invention, the metallurgical dust and sludge in the smelting process of the iron and steel enterprise is taken as a treatment object, the available value in the metallurgical dust and sludge can be fully excavated, meanwhile, the treatment process is shortened as far as possible, the treatment energy consumption is reduced, and the renewable resource utilization efficiency and economic benefit of the metallurgical dust and sludge are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solid waste utilization and regeneration, and particularly to a system and method for regenerating KCl, NaCl and zinc ingots by using metallurgical solid waste. Background Art

[0002] As one of the important production fields, the metallurgical industry generates a large quantity and variety of solid waste. With the increasing importance of environmental protection and sustainable resource utilization, the disposal and resource utilization of metallurgical solid waste have become urgent problems to be solved globally. The key to studying the resource utilization of metallurgical solid waste lies in making full use of the resource potential contained in these solid wastes, which can not only effectively reduce environmental pollution, but also realize the effective reuse of resources, meeting the strategic goal of sustainable development. In addition, carrying out research on the resource utilization of different types of metallurgical solid waste is of great significance for improving the production efficiency of the metallurgical industry, reducing energy consumption and raw material costs, and promoting sustainable economic development.

[0003] Metallurgical solid waste refers to various wastes generated during the metallurgical production process, mainly including solid waste, liquid waste and waste gas. The resource utilization of metallurgical solid waste contains huge potential value, which is mainly reflected in many aspects.

[0004] Firstly, a large amount of valuable metal components are contained in the solid waste, such as iron, zinc, cadmium, copper, aluminum, etc. Through recycling and reuse, the mining and refining of raw ores can be reduced, thus saving energy costs and reducing environmental damage. Moreover, it also helps to reduce resource consumption, lower carbon emissions during the production process, and is conducive to slowing down the depletion of natural resources and global warming.

[0005] Secondly, the treatment of waste not only helps to reduce environmental pollution, but also plays a positive role in improving the ecological environment.

[0006] At the economic level, resource utilization creates new economic value for the metallurgical industry. Recycling valuable components in waste can bring new business opportunities, provide more raw material sources, reduce production costs, and enhance the competitiveness of enterprises. Moreover, establishing a circular economy model also provides a more sustainable development path for enterprises, making them more sustainable and viable in the long term.

[0007] A large amount of solid waste is generated during the steel production process. The iron-containing dust and sludge production of steel enterprises is about 10% of the steel output per ton. Among them, the dust with relatively high contents of elements such as zinc, lead, sodium, and potassium accounts for 25% - 30% of the dust volume of steel enterprises. These wastes are secondary resources that can be utilized, mainly including blast furnace dust or sludge, converter dust or sludge, and some rolling mill sludge, etc., which can be collectively called metallurgical dust and sludge. The traditional practice of recycling metallurgical dust and sludge is to directly return the recycled dust and sludge to sintering for utilization, resulting in the continuous cycling and enrichment of harmful elements such as zinc and lead in the system. With the increasing proportion of high-zinc scrap steel in steelmaking, the zinc content in the iron-containing dust and sludge materials gradually rises, leading to an excessive zinc load in the blast furnace, affecting the smooth operation of ironmaking production and the service life of equipment. Summary of the Invention

[0008] The main object of the present invention is to provide a system and method for recycling KCl, NaCl and zinc ingots using metallurgical solid waste, aiming to improve the utilization efficiency of recycled resources and economic benefits of metallurgical dust and sludge as much as possible.

[0009] To achieve the above object, the present invention provides a system for recycling KCl, NaCl and zinc ingots using metallurgical solid waste, including a water washing dechlorination and evaporation crystallization device, a rotary kiln defluorination and dechlorination device, a submerged arc furnace for extracting crude zinc, and a rectification tower for extracting refined zinc, which are arranged in sequence. Among them, The water washing dechlorination and evaporation crystallization device includes a sintering machine head ash water washing dechlorination raw material device, a secondary zinc oxide powder water washing dechlorination raw material device, a water washing dechlorination water washing and pressure filtration device communicated with the outlets of the sintering machine head ash water washing dechlorination raw material device and the secondary zinc oxide powder water washing dechlorination raw material device, and an evaporation crystallization device communicated with the outlet of the water washing dechlorination water washing and pressure filtration device; The washed material and secondary water obtained from the filter press of the secondary zinc oxide powder water washing dechlorination raw material device enter the rotary kiln of the rotary kiln defluorination and dechlorination device for reaction to carry out defluorination and dechlorination. The zinc calcine after defluorination and dechlorination enters the submerged arc furnace for extracting crude zinc to obtain crude zinc, and the crude zinc enters the rectification tower for extracting refined zinc device for separating zinc and cadmium to obtain pure zinc liquid.

[0010] Preferably, the sintering machine head ash water washing dechlorination raw material device includes a first rinsing tank, a first magnetic separator, a first filter press connected to the magnetic pulp outlet of the first magnetic separator, and a second filter press connected to the non-magnetic pulp outlet of the first magnetic separator.

[0011] Preferably, the secondary zinc oxide powder water washing dechlorination raw material device includes a screening device, a second rinsing tank, a third filter press, a third rinsing tank and a fourth filter press arranged in sequence.

[0012] Preferably, the water washing dechlorination water washing and pressure filtration device includes a first water purification tank, a fifth filter press, a purification tank, and a sixth filter press arranged in sequence; the evaporation crystallization device includes an MVR evaporation crystallizer communicated with the outlet of the water purification tank of the sixth filter press.

[0013] Preferably, the rotary kiln defluorination and dechlorination device includes a rotary kiln and a cooler arranged at the outlet of the rotary kiln; the submerged arc furnace for extracting crude zinc includes a submerged arc furnace.

[0014] Preferably, the refined zinc extraction device of the rectification column includes a first melting furnace, a lead column, a lead column condenser, a first liquation furnace, and a cadmium column. Among them, the first melting furnace, the lead column, and the lead column condenser are arranged in sequence. The steam outlet of the lead column condenser is communicated with the inlet of the cadmium column, and the liquid outlet of the lead column condenser is communicated with the inlet of the first liquation furnace.

[0015] Preferably, the refined zinc extraction device of the rectification column further includes a crude lead extraction device, which includes a second melting furnace for melting the hard zinc product of the first liquation furnace, a B# column connected to the second melting furnace, a B# column condenser connected to the steam outlet of the B# column, and a second liquation furnace communicated with the liquid outlet of the B# column.

[0016] Preferably, the refined zinc extraction device of the rectification column further includes a refined zinc holding furnace located at the liquid outlet of the cadmium column and an ingot casting device arranged at the outlet of the refined zinc holding furnace; the refined zinc extraction device of the rectification column further includes a secondary condenser located at the gas outlet of the cadmium column to recover high-cadmium zinc.

[0017] The present invention also provides a method based on the above system for recycling KCl, NaCl, and zinc ingots by using metallurgical solid waste, including the following steps: The sintering machine head ash enters the sintering machine head ash water washing and dechlorination raw material device. After the sintering machine head ash is rinsed, magnetically separated, and pressure filtered in sequence, high-quality iron powder and secondary water are obtained. The zinc oxide powder enters the secondary zinc oxide powder water washing and dechlorination raw material device and is sequentially screened, rinsed, and pressure filtered. The liquid obtained by pressure filtration and the secondary water of the sintering machine head ash enter the water washing and dechlorination water washing and pressure filtration device and the evaporation and crystallization device to obtain NaCl and KCl; The solid obtained by pressure filtration of the secondary zinc oxide powder water washing and dechlorination raw material device enters the rotary kiln of the rotary kiln defluorination and dechlorination device for reaction to carry out defluorination and dechlorination. The zinc calcine after defluorination and dechlorination enters the submerged arc furnace for crude zinc extraction device to obtain crude zinc, and the crude zinc enters the refined zinc extraction device of the rectification column to separate zinc and cadmium to obtain pure zinc liquid.

[0018] Preferably, the gas of the submerged arc furnace for crude zinc extraction device is also communicated with the rotary kiln inlet of the rotary kiln defluorination and dechlorination device as fuel.

[0019] The system for recycling KCl, NaCl, and zinc ingots by using metallurgical solid waste proposed by the present invention has the following beneficial effects: 1. This system uses metallurgical dust and sludge and can extract useful products such as low-quality iron powder, high-quality iron powder, sodium chloride, potassium chloride, refined zinc ingots, and crude lead, fully exploiting the available value in metallurgical dust and sludge. 2. This system has stable operation and reasonable structural design, shortening the treatment process and reducing the treatment energy consumption as much as possible, thereby improving the utilization efficiency of metallurgical dust and sludge renewable resources and economic benefits as much as possible.

[0020] 3. The traditional regeneration of metallurgical dust and sludge solid waste mainly focuses on extracting zinc and iron elements from the dust and sludge. On the one hand, the purity of the extracted zinc product is relatively low, mainly being crude zinc product, and the chlorides in the metallurgical dust and sludge are all regarded as waste without any recycling. In this system, not only is a process added after the crude zinc process to enable the extraction of refined zinc products; at the same time, the water washing dechlorination technology is used to regenerate the chlorides in the metallurgical dust and sludge into potassium chloride and sodium chloride with certain economic value, improving the recovery rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 FIG. is a schematic structural diagram of the system for regenerating KCl, NaCl and zinc ingots by using metallurgical solid waste according to the present invention; Figure 2 FIG. is a schematic structural diagram of the water washing dechlorination and evaporation crystallization device in the system for regenerating KCl, NaCl and zinc ingots by using metallurgical solid waste according to the present invention; Figure 3 FIG. is a schematic structural diagram of the rotary kiln defluorination and dechlorination device in the system for regenerating KCl, NaCl and zinc ingots by using metallurgical solid waste according to the present invention; Figure 4 FIG. is a schematic structural diagram of the submerged arc furnace for extracting crude zinc in the system for regenerating KCl, NaCl and zinc ingots by using metallurgical solid waste according to the present invention; Figure 5 FIG. is a schematic structural diagram of the rectification tower for extracting refined zinc in the system for regenerating KCl, NaCl and zinc ingots by using metallurgical solid waste according to the present invention.

[0022] In the figures, 1 - water washing dechlorination and evaporation crystallization device, 2 - rotary kiln defluorination and dechlorination device, 3 - submerged arc furnace for extracting crude zinc, 4 - rectification tower for extracting refined zinc, 5 - first rinsing tank, 6 - first magnetic separator, 7 - first filter press, 8 - second filter press, 9 - screening device, 10 - second rinsing tank, 11 - third filter press, 12 - third rinsing tank, 13 - fourth filter press, 14 - first water purification tank, 15 - fifth filter press, 16 - purification tank, 17 - sixth filter press, 18 - MVR evaporation crystallizer, 19 - rotary kiln, 20 - cooler, 21 - surface cooler, 22 - bag filter, 23 - submerged arc furnace, 24 - first melting furnace, 25 - lead tower, 26 - lead tower condenser, 27 - first liquation furnace, 28 - cadmium tower, 29 - second melting furnace, 30 - B# tower, 31 - B# tower condenser, 32 - second liquation furnace, 33 - refined zinc holding furnace, 34 - ingot casting equipment.

[0023] The realization of the object, functional features and advantages of the present invention will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0025] It should be noted that in the description of the present invention, the orientation or positional relationship indicated by terms such as "lateral", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to the present invention. In addition, terms such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0026] The present invention provides a system for recycling KCl, NaCl and zinc ingots from metallurgical solid waste.

[0027] Refer to Figure 1 , in this preferred embodiment, a system for recycling KCl, NaCl and zinc ingots from metallurgical solid waste is successively provided with a water washing dechlorination and evaporation crystallization device 1, a rotary kiln defluorination and dechlorination device 2, a submerged arc furnace for extracting crude zinc device 3 and a rectification tower for extracting refined zinc device 4. Among them, The water washing dechlorination and evaporation crystallization device 1 includes a sintering machine head ash water washing dechlorination raw material device, a secondary zinc oxide powder water washing dechlorination raw material device, a water washing dechlorination water washing and pressure filtration device communicated with the outlets of the sintering machine head ash water washing dechlorination raw material device and the secondary zinc oxide powder water washing dechlorination raw material device, and an evaporation crystallization device communicated with the outlet of the water washing dechlorination water washing and pressure filtration device; The washed materials and secondary water obtained from the filter press of the secondary zinc oxide powder water washing dechlorination raw material device enter the rotary kiln 19 of the rotary kiln defluorination and dechlorination device 2 for reaction to carry out defluorination and dechlorination. The zinc calcined sand after defluorination and dechlorination enters the submerged arc furnace for extracting crude zinc device 3 to obtain crude zinc, and the crude zinc enters the rectification tower for extracting refined zinc device 4 to separate zinc and cadmium to obtain pure zinc liquid.

[0028] In this embodiment, refer to Figure 1 and Figure 2 , the sintering machine head ash water washing dechlorination raw material device includes a first rinsing tank 5, a first magnetic separator 6, a first filter press 7 connected to the magnetic pulp outlet of the first magnetic separator 6, and a second filter press 8 connected to the non-magnetic pulp outlet of the first magnetic separator 6.

[0029] The secondary zinc oxide powder water washing dechlorination raw material device includes a screening device 9, a second rinsing tank 10, a third filter press 11, a third rinsing tank 12 and a fourth filter press 13 arranged in sequence.

[0030] The water washing and dechlorination and pressure filtration device includes a first purified water tank 14, a fifth pressure filter 15, a purification tank 16, and a sixth pressure filter 17 arranged in sequence. The evaporation and crystallization device includes an MVR evaporation and crystallization unit 18 communicated with the outlet of the purified water tank of the sixth pressure filter 17. The MVR evaporation and crystallization unit 18 mainly performs crystallization treatment on the solution containing and KCl. The solubility of NaCl and KCl is different, and the solubility of KCl is greater than that of NaCl. At different temperatures, the solubility ratio of the two is different. By converting different evaporation temperatures, the saturated states of the two salts correspond to different temperatures respectively, so that the two salts are precipitated separately.

[0031] Refer to Figure 1 and Figure 3 , the rotary kiln de-fluorination and de-chlorination device 2 includes a rotary kiln 19 and a cooler 20 arranged at the outlet of the rotary kiln 19; Refer to Figure 1 and Figure 4 , the submerged arc furnace for crude zinc extraction device 3 includes a submerged arc furnace 23.

[0032] Refer to Figure 1 and Figure 5 , the rectification tower for refined zinc extraction device 4 includes a first melting furnace 24, a lead tower 25, a lead tower condenser 26, a first liquation furnace 27, and a cadmium tower 28. Among them, the first melting furnace 24, the lead tower 25, and the lead tower condenser 26 are arranged in sequence. The steam outlet of the lead tower condenser 26 is communicated with the inlet of the cadmium tower 28, and the liquid outlet of the lead tower condenser 26 is communicated with the inlet of the first liquation furnace 27.

[0033] The rectification tower for refined zinc extraction device 4 further includes a crude lead extraction device, and the crude lead extraction device includes a second melting furnace 29 for melting the hard zinc product of the first liquation furnace 27, a B# tower 30 connected to the second melting furnace 29, a B# tower condenser 31 connected to the steam outlet of the B# tower 30, and a second liquation furnace 32 communicated with the liquid outlet of the B# tower 30.

[0034] The rectification tower for refined zinc extraction device 4 further includes a refined zinc holding furnace 33 located at the liquid outlet of the cadmium tower 28 and an ingot casting device 34 arranged at the outlet of the refined zinc holding furnace 33; The rectification tower for refined zinc extraction device 4 further includes a secondary condenser located at the gas outlet of the cadmium tower 28 to recover high-cadmium zinc.

[0035] The specific working process of the system for recycling KCl, NaCl, and zinc ingots using metallurgical solid waste is as follows.

[0036] I. Water washing and dechlorination and evaporation and crystallization device 1 Refer to Figure 1 and Figure 2, the sintering machine head ash enters the sintering machine head ash water washing and dechlorination raw material device. After adding chemicals in the first rinsing tank 5, the rinsed product enters the first magnetic separator 6 for magnetic separation. The magnetic slurry separated enters the first filter press 7 for pressure filtration to obtain secondary water and high-quality iron powder. After the non-magnetic slurry separated by the first magnetic separator 6 undergoes gravity separation, it enters the second filter press 8 for pressure filtration to obtain secondary water, tailings, and low-quality iron powder. The secondary water from the first filter press 7 enters the mixing tank, and the secondary water from the second filter press 8 enters the first rinsing tank 5 for recycling.

[0037] The secondary zinc oxide powder (from the dust removal ash of ironmaking and steelmaking) is screened by the screening device 9 (vibrating screen). The undersize material is sent to the mixing tank, and the oversize material is transported to the batching room of the rotary kiln 19. After adding chemicals in the mixing tank, it enters the second rinsing tank 10 for rinsing. The product of the second rinsing tank 10 then enters the third filter press 11 for pressure filtration. The liquid obtained from the pressure filtration enters the mixing tank and is mixed with the secondary water from the first filter press 7. The filter cake obtained from the pressure filtration is rinsed and pressure filtered successively by the third rinsing tank 12 and the fourth filter press 13, and the washed material obtained enters the rotary kiln 19.

[0038] The mixture in the mixing tank enters the first water purification tank 14. After adding chemicals, it is further pressure filtered by the fifth filter press 15. The primary water obtained by the fifth filter press 15 enters the purification tank 16 and is pressure filtered by the sixth filter press 17. The potassium and sodium wastewater obtained enters the MVR evaporation crystallizer 18, and the MVR evaporation crystallizer 18 separates out NaCl and KCl. The filter cake obtained by the fifth filter press 15 is slurried and then enters the third rinsing tank 12.

[0039] II. Rotary kiln defluorination and dechlorination device 2 Refer to Figure 1 and Figure 3 , the washed material and secondary water obtained by the fourth filter press 13, together with the wash-free material (referring to the secondary zinc oxide powder with a low chlorine content that does not require water washing and dechlorination), enter the batching room of the rotary kiln 19 for batching and then enter the rotary kiln 19. During the forward flow of the material in the rotary kiln 19, it is heated to a certain temperature. When the mixed material is in a working atmosphere of 950 - 1100 °C, fluorine and chlorine in the material are removed to obtain zinc calcine that meets the requirements of zinc smelting. The zinc calcine is cooled by the cooler 20 and then enters the submerged arc furnace 23.

[0040] During the entire calcination process of the rotary kiln 19, the inside of the rotary kiln 19 is in a negative pressure state. The dust in the flue gas settles in the sedimentation chamber, settles and cools in the subsequent process, and is finally collected by the bag filter 22. The flue gas meets the discharge standards after desulfurization and denitrification.

[0041] III. Submerged arc furnace crude zinc extraction device 3 Refer toFigure 1 and Figure 4 The zinc calcine produced by the rotary kiln 19 is combined with coke (or anthracite), and then silica, lime and other raw materials are transported into the submerged arc furnace 23 according to the batching ratio after weighing and batching. The raw materials are melted by high-temperature electric arc in the submerged arc furnace 23. ZnO in the zinc-containing materials is reduced by C to generate zinc vapor and CO. The CO gas and zinc vapor mixed with dust generated during the smelting process enter the condenser, and the zinc vapor is condensed into liquid zinc. The liquid zinc is then cast into crude zinc ingots.

[0042] IV. Refining tower for extracting refined zinc device 4 Refer to Figure 1 and Figure 5 In the refining tower for extracting refined zinc device, the rectification process of the electric furnace crude zinc is divided into two stages and carried out in two airtight rectification towers with different structures but similar principles. The first stage is carried out in the lead tower 25 to separate zinc, cadmium and other high-boiling impurity metals such as iron, lead and copper in the crude zinc, and produce residue zinc and cadmium-containing zinc. The second stage is carried out in the cadmium tower 28 to separate zinc from cadmium and produce high-cadmium zinc and high-purity refined zinc.

[0043] First, the crude zinc ingots obtained from the submerged arc furnace crude zinc device 3 are added into the first melting furnace 24 and then enter the lead tower 25. When overflowing from the upper evaporation tray to the lower evaporation tray of the lead tower 25, while being heated and raised in temperature by the combustion chamber, it exchanges heat with the rising metal vapor, so that the zinc liquid is fully heated, and most of the cadmium and zinc evaporate. At the same time, it rises to the reflux part together with the high-boiling metal lead mist and some high-boiling impurities entrained by the rising gas flow. By using the condensation and fractionation function of the reflux tray, the lead mist and some high-boiling impurities are washed down, and the zinc and cadmium vapor enter the lead tower condenser 26 and are condensed to obtain cadmium-containing zinc after condensation. Part of the zinc and high-boiling impurities enter the first liquation furnace 27 in liquid form. After being refined by the first liquation furnace 27, B# zinc (B# zinc is a low-cadmium zinc product obtained after rectifying the crude zinc in the lead tower 25, with extremely low cadmium content, called "cadmium-free zinc"), hard zinc, zinc dross and crude lead are obtained. Among them, B# zinc, hard zinc and zinc dross are returned to the second melting furnace 29 as raw materials. The cadmium-containing zinc vapor that has removed high-boiling impurity metals such as lead, iron and copper enters the cadmium tower 28. By appropriately controlling conditions such as the temperature of the combustion chamber, the evaporation and condensation reflux process is also carried out and then enters the large condenser of the cadmium tower, so that the zinc and cadmium vapor are further separated and enriched. The high-cadmium zinc vapor enters the high-cadmium zinc condenser for further condensation (that is, after secondary condensation) to produce high-cadmium zinc as the raw material for cadmium extraction. The pure zinc liquid that has removed cadmium enters the pure zinc storage tank through the lower extension part and is regularly discharged for casting to obtain refined zinc ingots.

[0044] Among the products obtained from the first liquation furnace 27, the B# zinc, hard zinc, and zinc dross enter the second melting furnace 29 to be melted and then enter the B# tower 30 (the B# tower 30 is mainly used to refine crude zinc and is an existing device). The steam from the B# tower 30 enters the B# tower condenser 31, and the liquid product of the B# tower 30 enters the B# tower condenser 31 and then enters the second liquation furnace 32. After being refined in the second liquation furnace 32, B# zinc, hard zinc, zinc dross, and crude lead are obtained. The hard zinc and zinc dross in the products are returned to the first liquation furnace 27 for recycling.

[0045] The system for recycling KCl, NaCl, and zinc ingots using metallurgical solid waste proposed by the present invention has the following beneficial effects: 1. This system uses metallurgical dust and sludge and can extract useful products such as low-grade iron powder, high-grade iron powder, sodium chloride, potassium chloride, refined zinc ingots, and crude lead, fully tapping the utilizable value in the metallurgical dust and sludge. 2. This system has stable operation and a reasonable structural design, shortening the treatment process and reducing the treatment energy consumption as much as possible, thereby improving the utilization efficiency of metallurgical dust and sludge renewable resources and economic benefits as much as possible.

[0046] 3. The traditional recycling of metallurgical dust and sludge solid waste mainly extracts zinc and iron elements from the dust and sludge. On the one hand, the purity of the extracted zinc product is relatively low, mainly being crude zinc products, and the chlorides in the metallurgical dust and sludge are all regarded as waste and not recycled at all. In this system, not only are processes added after the crude zinc process to enable the extraction of refined zinc products; at the same time, the water washing and dechlorination technology is used to recycle the chlorides in the metallurgical dust and sludge into potassium chloride and sodium chloride with certain economic value, improving the recovery rate.

[0047] The present invention also proposes a method for a system for recycling KCl, NaCl, and zinc ingots using metallurgical solid waste.

[0048] In this preferred embodiment, a method for a system for recycling KCl, NaCl, and zinc ingots based on the above-mentioned metallurgical solid waste includes the following steps: The sintering machine head ash enters the sintering machine head ash water washing and dechlorination raw material device. The sintering machine head ash is sequentially subjected to rinsing, magnetic separation, and pressure filtration to obtain high-grade iron powder and secondary water. The zinc oxide powder enters the secondary zinc oxide powder water washing and dechlorination raw material device and is sequentially screened, rinsed, and pressure filtered. The liquid from the pressure filtration and the secondary water of the sintering machine head ash enter the water washing and dechlorination water pressure filtration device and the evaporation and crystallization device to obtain NaCl and KCl; The solid from the pressure filtration of the secondary zinc oxide powder water washing and dechlorination raw material device enters the rotary kiln 19 of the rotary kiln defluorination and dechlorination device 2 for reaction to carry out defluorination and dechlorination. The zinc calcine after defluorination and dechlorination enters the crude zinc extraction device 3 of the submerged arc furnace 23 to obtain crude zinc, and the crude zinc enters the refined zinc extraction device 4 of the rectification tower to separate zinc and cadmium to obtain pure zinc liquid.

[0049] Further, the gas from the crude zinc extraction device 3 of the submerged arc furnace 23 is also connected to the inlet of the rotary kiln 19 of the rotary kiln defluorination and dechlorination device 2 as fuel.

[0050] The method proposed by the present invention has a reasonable process design, shortening the treatment process and reducing the treatment energy consumption as much as possible, thereby greatly improving the utilization efficiency of metallurgical dust and sludge renewable resources and economic benefits.

[0051] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structural transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A system for recycling KCl, NaCl and zinc ingots using metallurgical solid waste, characterized in that, It includes a water washing dechlorination and evaporation crystallization device, a rotary kiln defluorination and dechlorination device, a submerged arc furnace crude zinc extraction device and a distillation tower refined zinc extraction device, which are arranged in sequence. The water washing, dechlorination and evaporation crystallization device comprises a sintering head ash water washing and dechlorination raw material device, a secondary zinc oxide powder water washing and dechlorination raw material device, a water washing and dechlorination water filter press device connected to the outlets of the sintering head ash water washing and dechlorination raw material device and the secondary zinc oxide powder water washing and dechlorination raw material device, and an evaporation crystallization device connected to the outlet of the water washing and dechlorination water filter press device; The washing material and secondary water obtained from the filter press of the secondary zinc oxide powder water washing and dechlorination raw material device enter the rotary kiln of the rotary kiln defluorination and dechlorination device to react for defluorination and dechlorination. The zinc sand after defluorination and dechlorination enters the submerged arc furnace crude zinc extraction device to obtain crude zinc. The crude zinc enters the distillation tower refined zinc extraction device to separate zinc and cadmium to obtain pure zinc liquid.

2. The system for regenerating KCl, NaCl and zinc ingots using metallurgical solid waste according to claim 1, characterized in that: The sintering machine head ash water washing and dechlorination raw material device includes a first rinsing tank, a first magnetic separator, a first filter press connected to the magnetic slurry outlet of the first magnetic separator, and a second filter press connected to the non-magnetic slurry outlet of the first magnetic separator.

3. The system for recycling KCl, NaCl and zinc ingots using metallurgical solid waste as claimed in claim 1, wherein, The secondary zinc oxide powder water-washing and dechlorination raw material device comprises a screening device, a second rinsing tank, a third filter press, a third rinsing tank and a fourth filter press which are arranged in sequence.

4. The system for recycling KCl, NaCl and zinc ingots by using metallurgical solid waste according to claim 1, characterized in that, The water washing and dechlorination water washing filter press device includes a first clean water tank, a fifth filter press, a purification tank, and a sixth filter press arranged in sequence; the evaporation crystallization device includes an MVR evaporation crystallizer connected to the clean water tank outlet of the sixth filter press.

5. The system for recycling KCl, NaCl and zinc ingots by using metallurgical solid waste according to claim 1, characterized in that, The rotary kiln defluorination and dechlorination device includes a rotary kiln and a cooler arranged at the outlet of the rotary kiln; the submerged arc furnace crude zinc extraction device includes a submerged arc furnace.

6. The system for recycling KCl, NaCl and zinc ingots by using metallurgical solid waste according to any one of claims 1 to 5, characterized in that, The device for extracting refined zinc using a distillation tower includes a first melting furnace, a lead tower, a lead tower condenser, a first smelting furnace and a cadmium tower, wherein the first melting furnace, the lead tower and the lead tower condenser are arranged in sequence, the steam outlet of the lead tower condenser is connected to the inlet of the cadmium tower, and the liquid outlet of the lead tower condenser is connected to the inlet of the first smelting furnace.

7. The system for recycling KCl, NaCl and zinc ingots using metallurgical solid waste according to claim 6, characterized in that, The device for extracting refined zinc using a distillation tower also includes a crude lead extraction device, which includes a second melting furnace for melting the hard zinc product of the first smelting furnace, a B# tower connected to the second melting furnace, a B# tower condenser connected to the steam outlet of the B# tower, and a second smelting furnace connected to the liquid outlet of the B# tower.

8. The system for recycling KCl, NaCl and zinc ingots by using metallurgical solid waste according to claim 1, wherein The device for extracting refined zinc from a distillation tower also includes a refined zinc holding furnace located at the liquid outlet of the cadmium tower and an ingot casting device arranged at the outlet of the refined zinc holding furnace; the device for extracting refined zinc from a distillation tower also includes a secondary condenser located at the gas outlet of the cadmium tower to recover high-cadmium zinc.

9. A method for a system of recycling KCl, NaCl and zinc ingots by using metallurgical solid waste according to any one of claims 1 to 8, characterized in that, The following steps are involved: The sintering machine head ash enters the sintering machine head ash water washing and dechlorination raw material device, and the sintering machine head ash is rinsed, magnetically separated and filtered in sequence to obtain high-quality iron powder and secondary water. The zinc oxide powder enters the secondary zinc oxide powder water washing and dechlorination raw material device and is screened, rinsed and filtered in sequence. The filtered liquid and the secondary water of the sintering machine head ash enter the water washing and dechlorination water washing and filter press device and the evaporation crystallization device to obtain NaCl and KCl. The solids filtered out from the secondary zinc oxide powder water washing and dechlorination raw material device enter the rotary kiln of the rotary kiln defluorination and dechlorination device to react for defluorination and dechlorination. The zinc sand after defluorination and dechlorination enters the submerged arc furnace crude zinc extraction device to obtain crude zinc. The crude zinc enters the distillation tower refined zinc extraction device to separate zinc and cadmium to obtain pure zinc liquid.

10. The method for the system of recycling KCl, NaCl and zinc ingots by using metallurgical solid waste as claimed in claim 9, wherein, The coal gas from the submerged arc furnace zinc crude extraction device is also connected to the rotary kiln inlet of the rotary kiln defluorination and dechlorination device to serve as fuel.

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