Phosphorite pellet roasting and smelting system

Abstract

The utility model discloses a phosphorite pellet roasting and smelting system. The system comprises a material distributing mechanism, a roasting device, a smelting electric furnace and a cooling machine which are sequentially connected in series. According to the trend of materials, the roasting device comprises a drying section, a preheating section, a roasting section and a soaking section. And hot air covers are independently arranged above the drying section, the preheating section, the roasting section and the soaking section in a covering manner. And air boxes are independently arranged below the drying section, the preheating section, the roasting section and the soaking section. The system comprises a series of comprehensive treatments of phosphorite green pellets from heat treatment to furnace-entering phosphorus preparation and subsequent slag, the three processes are coupled together, the energy utilization efficiency is greatly improved, meanwhile, the pollutant emission is remarkably reduced, the low-cost, high-efficiency and low-pollution green production purpose is achieved, and the system has remarkable social and economic benefits and is worthy of popularization and application. And the method has the advantages of wide application range, high production efficiency, low energy consumption, stable product quality, convenience in large-scale popularization and application and the like.

Description

Technical Field

[0001] The utility model relates to the resource utilization of phosphate ore, in particular to a phosphate ore pellet roasting and smelting system, belonging to the technical field of resource utilization of phosphate ore resources. Background Art

[0002] At present, the process of preparing yellow phosphorus from phosphate ore is mainly the electric furnace method: natural phosphate ore blocks are placed in an electric furnace together with a reducing agent for heating, and the reducing agent is used to reduce the phosphorus element in the form of yellow phosphorus flue gas at high temperature, and then the yellow phosphorus flue gas is cooled and collected to obtain yellow phosphorus. However, this process has high requirements for phosphate ore raw materials. Generally, the phosphate ore entering the furnace needs to have uniform particle size, low moisture and carbonate content, P2O5 content higher than 20%, and a certain thermal strength. In order to meet production needs, my country's yellow phosphorus production enterprises mainly use block phosphate rock as raw material. With the increasing consumption of high-quality phosphate ore, the high-quality phosphate ore that can be used for yellow phosphorus production is becoming less and less, the supply of natural phosphate block ore resources is becoming increasingly scarce, and the market price is also rising. Solving the problem of the source of ore for yellow phosphorus production is imminent and has become the key to ensuring the normal production of yellow phosphorus enterprises. Therefore, using fine-grained phosphate ore powder to prepare artificial phosphate ore pellets for use in the furnace to produce yellow phosphorus has become a new way.

[0003] The existing phosphate ore green pellets obtained by pelletizing waste phosphate rock powder cannot be directly sent to the electric furnace for phosphorus production due to their low strength. Therefore, the green pellets need to be heat-treated to improve the quality and strength of the pellets before they can meet the requirements of entering the furnace. The existing technology often applies existing heat treatment equipment used in other similar fields to heat-treat phosphate ore green pellets (such as CN117534044A uses a chain grate machine-rotary kiln system to heat-treat phosphate ore green pellets, and CN117303325A uses a horse-boiler furnace to heat-treat phosphate ore green pellets). Due to the differences between the properties of phosphate ore green pellets and other mineral pellets, directly applying existing heat treatment equipment can obtain finished phosphate ore pellets that meet the requirements of entering the furnace to a certain extent, but it inevitably has problems such as poor adaptability, high energy consumption, and unstable product quality. In addition, when preparing yellow phosphorus by the existing electric furnace method, cold natural phosphate ore or cold artificial pellets are placed in an electric furnace together with a cold reducing agent for heating, and the cold materials are heated to about 1500°C, which is bound to increase the power consumption. At the same time, the electric furnace will also produce a large amount of slag, which has a high temperature. Now, the slag is generally quenched with water, and then the low-temperature slag is transported away and stacked. This not only greatly wastes the heat of the high-temperature slag, but also the waste gas and wastewater generated by the water quenching of the slag will pollute the environment. Utility Model Content

[0004] In view of the lack of dedicated heat treatment equipment for phosphate ore pellets in the prior art, which leads to unstable quality of finished phosphate ore pellets, high production energy consumption, low production efficiency and other problems, the utility model provides a phosphate ore pellet roasting and smelting system, which is designed according to the characteristics of phosphate ore pellets and the requirements for the finished pellets to enter the furnace, and has the characteristics of high production efficiency, low energy consumption and stable product quality. Furthermore, the system includes a series of comprehensive treatments of phosphate ore raw pellets from heat treatment to furnace phosphorus production and subsequent slag, coupling the three major processes together, greatly improving energy utilization efficiency while significantly reducing pollutant emissions, achieving the goal of low-cost, high-efficiency and low-pollution green production, and also has significant social and economic benefits, a wide range of applications, and the characteristics of large-scale promotion and application.

[0005] In order to achieve the above technical objectives, the technical solutions adopted by the present utility model are specifically described as follows:

[0006] A phosphate ore pellet roasting and smelting system, the system includes a material distribution mechanism, a roasting device, a smelting electric furnace and a cooler arranged in series. According to the direction of the material, the roasting device includes a drying section, a preheating section, a roasting section and a soaking section. A hot air cover is independently provided above the drying section, the preheating section, the roasting section and the soaking section. A wind box is independently provided below the drying section, the preheating section, the roasting section and the soaking section.

[0007] The hot air inlet of the hot air hood arranged on the roasting section is connected to the hot air outlet of the hot air furnace through the first air duct. The air outlet of the wind box arranged below the roasting section is connected to the air inlet of the wind box arranged below the equalizing section through the second hot air duct. The hot air outlet of the hot air hood arranged on the equalizing section is connected to the fume inlet of the fume purification unit through the third air duct. The hot air outlet of the hot air hood arranged on the drying section and the preheating section is connected to the air supply port of the hot air furnace through the fourth air duct and the fifth air duct respectively.

[0008] Preferably, the material distribution mechanism includes a bottom material bunker, a bottom material distribution device, a phosphate ore green pellet conveying device and a phosphate ore green pellet distribution device. According to the direction of the material, the bottom material distribution device and the phosphate ore green pellet distribution device are sequentially arranged above the feed end of the roasting device. The bottom material bunker is arranged above the feed end of the bottom material distribution device, and the feed end of the bottom material bunker is connected to the discharge end of the natural phosphate ore conveying device. The discharge end of the phosphate ore green pellet conveying device is connected to the feed end of the phosphate ore green pellet distribution device.

[0009] Preferably, a gate valve and a bottom material feeding chute are also provided between the bottom material bin and the bottom material distributing device.

[0010] Preferably, the discharging end of the roasting device is also connected to the feeding end of the bottom silo through a return material conveying mechanism.

[0011] Preferably, the return material conveying mechanism comprises a high temperature bucket elevator, a high temperature bucket elevator discharge chute and a return material belt conveyor which are sequentially arranged in series. The discharge end of the roasting device is connected to the feed end of the high temperature bucket elevator and the feed end of the smelting electric furnace through a three-way distributor. The discharge end of the return material belt conveyor is connected to the feed end of the bottom bunker.

[0012] Preferably, the bottom air inlet of the high-temperature bucket elevator is connected to the first fan. The top air outlet of the high-temperature bucket elevator is connected to the air supply port of the hot blast furnace through the sixth air duct.

[0013] Preferably, the feeding end of the three-way distributor and the discharging end of the roasting device are connected via a high-temperature material guide chute.

[0014] Preferably, the top feed port of the smelting electric furnace is connected to the discharge end of the three-way distributor through a smelting feed chute. The bottom slag discharge port of the smelting electric furnace is connected to the feed end of the cooler through a high-temperature slag chute. A phosphorus-containing gas collection pipeline is also connected to the upper gas outlet of the smelting electric furnace.

[0015] Preferably, the cooler is a ring cooler, and according to the direction of the material, the cooler includes a high temperature section, a medium temperature section and a low temperature section. The bottom cooling air inlet of the low temperature section is connected to the second fan. The top hot air outlet of the low temperature section is connected to the bottom air inlet of the high temperature section through the seventh air duct, and the top hot air outlet of the high temperature section is connected to the air inlet of the wind box arranged below the preheating section through the eighth air duct. The bottom cooling air inlet of the medium temperature section is connected to the third fan, and the top hot air outlet of the medium temperature section is connected to the air inlet of the wind box arranged below the drying section through the ninth air duct.

[0016] Preferably, the system further comprises a bar screening device. The bar screening device comprises screen bars and a lower hopper. The lower hopper is arranged below the screen bars. The feed end of the screen bars is connected to the bottom slag discharge port of the smelting electric furnace through a high-temperature slag chute, and the discharge end of the lower hopper is connected to the feed end of the cooler through the lower chute.

[0017] Preferably, a fume hood is provided above the strip screening device, and the bottom air inlet of the lower hopper is connected to a fourth fan. The hot air outlet of the fume hood is connected to the air inlet of the wind box provided below the equalizing section through a tenth air duct.

[0018] Preferably, the system further comprises a slag crushing device. The feed end of the slag crushing device is connected to the discharge end of the discharge chute, and the discharge end of the slag crushing device is connected to the feed end of the cooler through the crushing chute.

[0019] Preferably, the flue gas purification unit comprises a denitration device, a dust collector, a main exhaust fan, a desulfurization device and a chimney arranged in series. The air inlet of the denitration device is connected to the hot air outlet of the hot air hood arranged on the heat equalization section through a third air duct.

[0020] Preferably, the system further comprises a dust collecting device, the feed end of the dust collecting device is connected to the dust discharge end of the dust collector via a dust conveying pipeline and a dust bin pump.

[0021] Preferably, the system further comprises a bulk material collecting device, the feed end of which is connected to the bulk material outlets of all the bellows via a bulk material belt conveyor and a bulk material chute.

[0022] Preferably, the roasting device is a ring roasting machine, and double-layer ash discharge valves are independently provided at the bulk material outlets of all wind boxes.

[0023] In the utility model, powder ore generated in the production process of obtaining natural phosphate ore lump ore and powder and bulk materials generated in the roasting process of artificial pellet ore are collected and used as raw materials for phosphate ore pelletizing. After pelletizing, they are processed by the system of the utility model and used for yellow phosphorus production, which can effectively utilize powder ore resources, effectively alleviate the problem of raw material shortage in yellow phosphorus enterprises, effectively reduce raw material costs, and save land resources. This is in line with the national industrial policy and resource development strategy, and is of great significance to my country's yellow phosphorus production enterprises.

[0024] In the utility model, the phosphate ore pellet roasting and smelting system of the utility model includes a distribution mechanism, a roasting device, a smelting electric furnace and a cooler, etc., which are arranged in series in sequence. By coupling the distribution, roasting, smelting and slag cooling of the phosphate ore pellets into one, on the one hand, the site occupation is reduced and land resources are saved. In addition, the system of the utility model can directly enter the electric furnace for phosphorus smelting without cooling the high-temperature phosphate ore pellets roasted by the ring roasting machine, and the temperature quickly reaches a high point, which not only greatly reduces the power consumption of the electric furnace, but also shortens the phosphorus smelting time, improves production efficiency, and increases output. Furthermore, the system can also recycle the sensible heat of the slag, significantly reducing the energy consumption in the process of roasting the phosphate ore pellets, and reducing the emission of waste gas and wastewater as a whole.

[0025] In the utility model, the material distribution mechanism includes a bottom material bin, a bottom material distribution device, a phosphate ore green pellet conveying device and a phosphate ore green pellet distribution device, etc. The material distribution mechanism is connected to the discharge end of the roasting device through a return material conveying mechanism, wherein the return material conveying mechanism includes a high-temperature bucket elevator, a high-temperature bucket elevator discharge chute and a return material belt conveyor arranged in series in sequence, the inlet of the high-temperature bucket elevator receives the high-temperature phosphate ore pellets discharged from the roasting device, the discharge port of the high-temperature bucket elevator is connected to the tail receiving point of the return material belt conveyor through the high-temperature bucket elevator discharge chute, and the return material The unloading point at the head of the belt conveyor is connected to an inlet at the top of the bottom bunker through a chute, and another inlet at the top of the bottom bunker is used to receive natural phosphate ore blocks. The discharge port below the bottom bunker is connected to a manual gate valve, and the bottom of the manual gate valve is connected to a bottom material distributing device. The phosphate ore raw pellet distributing device is arranged above the feeding port of the ring roaster in parallel with the bottom material distributing device, and the phosphate ore raw pellet distributing device is arranged in front of the material flow direction of the ring roaster relative to the bottom material distributing device. The upper inlet of the phosphate ore pellet distributing device is connected to the phosphate ore raw pellet conveying device for receiving phosphate ore raw pellets. That is, in the system of the utility model, a small amount of natural phosphate ore block ore or finished phosphate ore reverse ore is used as a bottom material, and is matched with raw phosphate ore pellets, which can not only protect the ring roaster trolley, but also increase the air permeability, and can also improve the grade and output of finished pellets and block ore. After the natural phosphate ore block ore is roasted at high temperature, the metallurgical properties can be improved, the subsequent phosphorus production can be promoted, and the energy consumption of phosphorus production can be reduced.

[0026] In the utility model, the roasting device is a ring roasting machine. In addition to its inlet and outlet, the ring roasting machine is provided with a hot air hood on the top. The ring roasting machine and the hot air hood are divided into a drying section, a preheating section, a roasting section, and a heat equalization section. A bellows is provided below the ring roasting machine corresponding to each section. A double-layer ash unloading valve is independently provided below each bellows. A high-temperature material guide chute is provided at the outlet of the ring roasting machine. The outlet of the high-temperature material guide chute is connected to the inlet of a three-way distributor, one outlet of the three-way distributor is connected to the inlet of a high-temperature bucket elevator, and the other outlet of the three-way distributor is connected to the inlet of a smelting electric furnace. The top of the smelting electric furnace discharges phosphorus-containing gas through a phosphorus-containing gas collection pipeline, and the slag discharge port at the bottom of the smelting electric furnace is connected to the inlet of the high-temperature slag chute. The material in the smelting electric furnace is continuously heated together with the reducing agent, and the reducing property of the reducing agent at high temperature is used to make the phosphorus element in the material escape from the top flue gas port of the smelting electric furnace in the form of yellow phosphorus flue gas, and then the yellow phosphorus flue gas is cooled and collected to obtain yellow phosphorus, and the high-temperature slag left in the smelting electric furnace is discharged from the bottom of the smelting electric furnace. That is, in the system of the utility model, the ring roasting machine is used to roast the phosphate ore pellets, which improves the utilization rate of the trolley and increases the output. The ring roasting machine is divided into a drying section, a preheating section, a roasting section, and a soaking section. The temperature is gradually increased, which can stably improve the metallurgical properties of the phosphate ore pellets, reduce the amount of broken balls, and further improve the thermal energy utilization rate; in addition, the high-temperature phosphate ore pellets roasted by the ring roasting machine are not cooled, and directly enter the electric furnace for phosphorus smelting, and the temperature quickly reaches a high point, which not only greatly reduces the power consumption of the electric furnace, but also shortens the phosphorus smelting time, improves production efficiency, and increases output.

[0027] In the utility model, the cooler is a ring cooler. According to the direction of the material, the cooler includes a high temperature section, a medium temperature section and a low temperature section. The slag discharged from the electric furnace is sent to the ring cooler for cooling and then the low temperature slag is discharged. In the low temperature section: the cooling fan is connected to the lower bellows of the low temperature section of the ring cooler through an air duct, and the upper wind hood of the low temperature section of the ring cooler is connected to the lower bellows of the high temperature section of the ring cooler through an air duct. In the medium temperature section: the cooling fan is connected to the lower bellows of the medium temperature section of the ring cooler through an air duct, and the upper wind hood of the medium temperature section of the ring cooler is connected to the lower bellows of the drying section of the ring roasting machine through an air duct. In the high temperature section: the upper wind hood of the high temperature section of the ring cooler is connected to the lower bellows of the preheating section of the ring roasting machine through an air duct. On the ring roasting machine: the air outlet of the hot blast furnace is connected to the hot air hood on the roasting section of the ring roasting machine through an air duct, and the lower wind box of the roasting section of the ring roasting machine is connected to the lower wind box of the equalizing section of the ring roasting machine through an air duct; the hot air hood on the drying section of the ring roasting machine is connected to the first air supply port of the hot blast furnace through an air duct, and the hot air hood on the preheating section of the ring roasting machine is connected to the second air supply port of the hot blast furnace through an air duct; in addition, the cooling fan is connected to the bottom flue gas inlet of the high-temperature bucket elevator through an air duct, and the top flue gas outlet of the high-temperature bucket elevator is connected to the third air supply port of the hot blast furnace through an air duct. That is to say, in the present invention, the cooling fan blows normal temperature air into the low temperature section of the ring cooler to cool the slag, the flue gas after cooling in the low temperature section is circulated to cool the slag in the high temperature section of the ring cooler, and the flue gas after cooling in the high temperature section of the ring cooler is circulated to the preheating section of the ring roaster to preheat the material; at the same time, the cooling fan blows normal temperature air into the medium temperature section of the ring cooler to cool the slag, and the flue gas after cooling in the medium temperature section of the ring cooler is circulated to the drying section of the ring roaster to dry the material. The hot blast furnace burns coal gas or coal powder to generate hot blast to roast the material in the roasting section of the ring roaster, and the flue gas in the drying section and preheating section of the ring roaster are recycled to the hot blast furnace to supplement the hot blast furnace with high temperature oxygen-containing flue gas for combustion, and the flue gas in the roasting section of the ring roaster is recycled to the equalizing section of the ring roaster to equalize the material. The cooling fan cools a small amount of high-temperature materials from the high-temperature bucket elevator, and the cooled flue gas is also circulated to the hot blast furnace to supplement the hot blast furnace with high-temperature oxygen-containing flue gas for combustion. That is, the utility model reduces energy consumption and carbon emissions through the recycling of hot air at various levels, while ensuring the stability of the roasting system operation, effectively ensuring the quality of the finished phosphate ore pellets, and reducing production costs. The utility model cools the slag by recycling the flue gas from the low-temperature section of the ring cooler to the high-temperature section of the ring cooler, and the cooled flue gas preheats the materials in the preheating section of the ring roaster; the flue gas from the medium-temperature section of the ring cooler dries the materials in the drying section of the ring roaster, thereby realizing the cascade utilization of the flue gas of the ring cooler and achieving zero emissions.

[0028] In the utility model, the system of the utility model also includes a strip screening device and a crushing device. The strip screening device and the crushing device are sequentially arranged between the smelting electric furnace and the cooler, and the strip screening device includes screen bars and a lower hopper. The inlet of the screen bars is connected to the outlet of the high-temperature slag chute, a strip screening device lower hopper is arranged below the strip screen bars, and a strip screening device upper fume hood is arranged above the screen bars. The outlet of the strip screening device lower hopper is connected to the inlet of the crushing device through the lower chute, and the outlet of the crushing device is connected to the inlet of the ring cooler through the crushing chute. The slag with a certain fluidity is fed into the strip screening device, and the strip screening device screens the slag with a certain fluidity into strips, and flows into the lower hopper below, and cools the strip slag at the same time (the high-temperature slag with a certain fluidity is first made into strips, and when cooled with air, it can not only increase the cooling area and improve the heat recovery rate, but also prevent the slag from forming large blocks). The cooled strip slag is sent to the crushing device. After the crushing device crushes the strip slag, it is sent to the ring cooler for cooling. The cooling fan blows normal temperature air into the lower hopper of the strip screening device to cool the strip slag. The cooled flue gas is discharged from the upper flue gas hood of the strip screening device and circulated to the heat equalization section of the ring roasting machine to equalize the material. By recycling the heat energy of the high-temperature slag generated by the electric furnace, it not only improves the heat utilization rate and reduces the cost, but also is environmentally friendly and does not produce waste gas and wastewater to pollute the environment. After the cooled strip slag is crushed again, it is cooled and collected by the ring cooler again. After the heat energy is recovered through the high temperature section, medium temperature section, and low temperature section of the ring cooler, the room temperature slag is obtained, so that the heat recovery reaches more than 90%, avoiding the waste of heat energy.

[0029] In the utility model, the flue gas purification unit includes a high-temperature denitrification device, a dust collector, a main exhaust fan, a desulfurization device, and a chimney. The inlet of the high-temperature denitrification device is connected to the hot air hood on the heat soaking section of the ring roasting machine through an air duct, the outlet of the high-temperature denitrification device is connected to the inlet of the dust collector through an air duct, the outlet of the dust collector is connected to the inlet of the main exhaust fan through an air duct, the outlet of the main exhaust fan is connected to the inlet of the desulfurization device through an air duct, and the outlet of the desulfurization device is connected to the chimney through an air duct. The flue gas discharged from the heat soaking section of the ring roasting machine is first denitrified in the high-temperature denitrification device, and then dedusts, desulfurizes, and then is discharged through the chimney. The high-temperature flue gas generated by the heat soaking section of the ring roasting machine is discharged as waste gas. Because it is high temperature, it just meets the requirements of denitrification. The denitrification treatment is first carried out. The existing denitrification requires the waste gas to be heated before the denitrification catalyst can be used. After the flue gas of the utility model is circulated for many times, it can be denitrified without reheating, which saves a lot of cost for denitrification. The temperature of the flue gas after desulfurization is just suitable for the dust collector, which can avoid high temperature damaging the dust collector and low temperature causing water damage to the dust collector. The flue gas after the dust collector is then sent to the desulfurization through the main exhaust fan, and the temperature is also suitable for high-efficiency desulfurization. After desulfurization, it is discharged through the chimney, realizing the full utilization of flue gas heat and completing the removal of harmful substances. It is discharged to the outside as clean gas without any pollution.

[0030] In the utility model, the system also includes a dust collection device and a bulk material collection device. The utility model discharges the bulk material in the bellows of the ring roaster through a double-layer ash discharge valve into a bulk material belt conveyor, and the bulk material belt conveyor then sends the bulk material to be used for making phosphate ore pellets; the dust collected by the dust collector is sent through the dust conveying device to be used for making phosphate ore pellets. The phosphate ore pellets made with the powder ore as raw materials are then dried, preheated, roasted, and evenly heated on the ring roaster, and then sent to the smelting electric furnace for smelting, so as to realize resource recycling. The finely crushed materials produced by the ring roaster are transported into the belt conveyor through the double-layer ash discharge valve and are used as raw materials for continuous pelletizing; the dust collected by the dust collector is transported through the dust conveying device and is also used as raw materials for continuous pelletizing, so as to realize resource recycling and circular utilization, and also avoid direct external discharge to pollute the environment.

[0031] In the utility model, the width of the roasting device (in the horizontal plane perpendicular to the direction of the material) is 0.3-10m, preferably 1-8m, more preferably 3-5m; the height of the hot air hood is 0.1-5m, preferably 0.3-3m, more preferably 0.5-2m. Temperature detectors (such as thermocouples) can also be independently provided in the hot air hoods corresponding to the drying section, preheating section, roasting section and soaking section, so as to reasonably control the temperature of each section and thus ensure product quality.

[0032] Compared with the prior art, the beneficial technical effects of the utility model are as follows:

[0033] 1: The system of the utility model adopts a ring roasting machine to roast phosphate ore pellets, which improves the utilization rate of the trolley, increases the output, and the temperature of the drying section, preheating section, roasting section, and soaking section is gradually increased, which can stably improve the metallurgical properties of the phosphate ore pellets, reduce the amount of broken balls, and further improve the utilization rate of thermal energy. In addition, the high-temperature phosphate ore pellets roasted by the ring roasting machine are not cooled, but directly enter the electric furnace for phosphorus smelting. The temperature quickly reaches a high point, which not only greatly reduces the power consumption of the electric furnace, but also shortens the phosphorus smelting time, improves production efficiency, and increases output.

[0034] 2: The system of the utility model recycles the heat energy of the high-temperature slag generated by the electric furnace, which not only improves the heat utilization rate and reduces the cost, but is also environmentally friendly and will not produce waste gas and wastewater to pollute the environment. The flue gas from the low-temperature section of the ring cooler is further circulated to the high-temperature section of the ring cooler to cool the slag, and the cooled flue gas is then used to preheat the material in the preheating section of the ring roasting machine; the flue gas from the medium-temperature section of the ring cooler is used to dry the material in the drying section of the ring roasting machine, realizing the cascade utilization of the flue gas of the ring cooler and basically achieving zero emission of ring cooling waste gas.

[0035] 3: The system of the utility model first makes the high-temperature slag with a certain fluidity into strips. When cooled with air, it can not only increase the cooling area and improve the heat recovery rate, but also prevent the slag from forming large blocks. The cooled strip slag is then broken up and cooled again by a ring cooler to collect heat energy. After the heat energy is recovered by the high-temperature section, medium-temperature section and low-temperature section of the ring cooler, room-temperature slag is obtained, so that the heat recovery rate reaches more than 90%, avoiding the waste of heat energy.

[0036] 4: The system of the utility model is roasted by a ring roaster, and the obtained phosphate ore pellets have good quality, high strength, low moisture content, and low carbonate content, which can effectively reduce the energy consumption of subsequent pelletized ore phosphorus production and improve economic benefits. In addition, the system components of the utility model are organized in an orderly and reasonable manner, and the layout of the site requirements greatly saves land resources, can meet various terrain requirements, and has a wide range of applications; in addition, the system of the utility model is also simple to operate, high in production efficiency, and stable in system operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The figure is a simplified structural diagram of the system of the utility model.

[0038] Figure 2 It is a schematic diagram of the overall structure of the system of the utility model.

[0039] Reference numerals: 1: material distribution mechanism; 101: bottom material bin; 102: bottom material distribution device; 103: phosphate ore green pellet conveying device; 104: phosphate ore green pellet distribution device; 105: natural phosphate lump ore conveying device; 106: gate valve; 107: bottom material feeding chute; 2: roasting device; 201: drying section; 202: preheating section; 203: roasting section; 204: equalizing section; 205: hot air hood; 206: bellows; 2 07: High-temperature guide chute; 3: Smelting electric furnace; 301: Smelting feed chute; 302: High-temperature slag chute; 303: Phosphorus-containing gas collection pipeline; 4: Cooler; 401: High-temperature section; 402: Medium-temperature section; 403: Low-temperature section; 5: Hot blast furnace; 6: Return material conveying mechanism; 601: High-temperature bucket elevator; 602: High-temperature bucket elevator discharge chute; 603: Return material belt conveyor; 7: Three-way distributor; 8: Strip screen Sub-device; 801: Screen bar; 802: Discharging hopper; 803: Discharging chute; 804: Smoke hood; 9: Slag crushing device; 901: Crushing chute; 10: Smoke purification unit; 1001: Denitration device; 1002: Dust collector; 1003: Main exhaust fan; 1004: Desulfurization device; 1005: Chimney; 11: Dust collection device; 1101: Dust conveying pipeline; 1102: Dust silo pump; 12: Bulk material collection Device; 1201: bulk material belt conveyor; 1202: bulk material chute; 1203: double-layer ash unloading valve; R1: first air duct; R2: second air duct; R3: third air duct; R4: fourth air duct; R5: fifth air duct; R6: sixth air duct; R7: seventh air duct; R8: eighth air duct; R9: ninth air duct; R10: tenth air duct; F1: first fan; F2: second fan; F3: third fan; F4: fourth fan. DETAILED DESCRIPTION

[0040] The technical solution of the utility model is illustrated below, and the scope of protection requested for the utility model includes but is not limited to the following embodiments.

[0041] A phosphate ore pellet roasting and smelting system, the system comprises a material distribution mechanism 1, a roasting device 2, a smelting electric furnace 3 and a cooler 4 which are arranged in series. According to the direction of the material, the roasting device 2 comprises a drying section 201, a preheating section 202, a roasting section 203 and a soaking section 204. A hot air cover 205 is independently provided above the drying section 201, the preheating section 202, the roasting section 203 and the soaking section 204. A wind box 206 is independently provided below the drying section 201, the preheating section 202, the roasting section 203 and the soaking section 204.

[0042] The hot air inlet of the hot air hood 205 covered on the roasting section 203 is connected to the hot air outlet of the hot air furnace 5 through the first air duct R1. The air outlet of the wind box 206 arranged below the roasting section 203 is connected to the air inlet of the wind box 206 arranged below the equalizing section 204 through the second hot air duct R2. The hot air outlet of the hot air hood 205 covered on the equalizing section 204 is connected to the smoke inlet of the smoke purification unit 10 through the third air duct R3. The hot air outlet of the hot air hood 205 covered on the drying section 201 and the preheating section 202 is connected to the air supply port of the hot air furnace 5 through the fourth air duct R4 and the fifth air duct R5 respectively.

[0043] Preferably, the material distribution mechanism 1 includes a bottom material bunker 101, a bottom material distribution device 102, a phosphate ore green pellet conveying device 103, and a phosphate ore green pellet distribution device 104. According to the direction of the material, the bottom material distribution device 102 and the phosphate ore green pellet distribution device 104 are sequentially arranged above the feed end of the roasting device 2. The bottom material bunker 101 is arranged above the feed end of the bottom material distribution device 102, and the feed end of the bottom material bunker 101 is connected to the discharge end of the natural phosphate ore conveying device 105. The discharge end of the phosphate ore green pellet conveying device 103 is connected to the feed end of the phosphate ore green pellet distribution device 104.

[0044] Preferably, a gate valve 106 and a bottom material feeding chute 107 are further provided between the bottom material bin 101 and the bottom material distributing device 102 .

[0045] Preferably, the discharging end of the roasting device 2 is also connected to the feeding end of the bottom material bin 101 through the return material conveying mechanism 6.

[0046] Preferably, the return material conveying mechanism 6 comprises a high temperature bucket elevator 601, a high temperature bucket elevator discharge chute 602 and a return material belt conveyor 603 which are sequentially arranged in series. The discharge end of the roasting device 2 is connected to the feed end of the high temperature bucket elevator 601 and the feed end of the smelting electric furnace 3 through a three-way distributor 7. The discharge end of the return material belt conveyor 603 is connected to the feed end of the bottom bunker 101.

[0047] Preferably, the bottom air inlet of the high-temperature bucket elevator 601 is connected to the first fan F1. The top air outlet of the high-temperature bucket elevator 601 is connected to the air supply port of the hot blast furnace 5 through the sixth air duct R6.

[0048] Preferably, the feeding end of the three-way distributor 7 and the discharging end of the roasting device 2 are connected via a high-temperature material guiding chute 207 .

[0049] Preferably, the top feed port of the smelting electric furnace 3 is connected to the discharge end of the three-way distributor 7 through the smelting feed chute 301. The bottom slag discharge port of the smelting electric furnace 3 is connected to the feed end of the cooler 4 through the high-temperature slag chute 302. A phosphorus-containing gas collection pipeline 303 is also connected to the upper gas outlet of the smelting electric furnace 3.

[0050] Preferably, the cooler 4 is a ring cooler. According to the direction of the material, the cooler 4 includes a high temperature section 401, a medium temperature section 402 and a low temperature section 403. The bottom cooling air inlet of the low temperature section 403 is connected to the second fan F2. The top hot air outlet of the low temperature section 403 is connected to the bottom air inlet of the high temperature section 401 through the seventh air duct R7, and the top hot air outlet of the high temperature section 401 is connected to the air inlet of the wind box 206 arranged below the preheating section 202 through the eighth air duct R8. The bottom cooling air inlet of the medium temperature section 402 is connected to the third fan F3, and the top hot air outlet of the medium temperature section 402 is connected to the air inlet of the wind box 206 arranged below the drying section 201 through the ninth air duct R9.

[0051] Preferably, the system further comprises a bar screening device 8. The bar screening device 8 comprises a screen bar 801 and a lower hopper 802. The lower hopper 802 is arranged below the screen bar 801. The feed end of the screen bar 801 is connected to the bottom slag discharge port of the smelting electric furnace 3 through the high-temperature slag chute 302, and the discharge end of the lower hopper 802 is connected to the feed end of the cooler 4 through the lower chute 803.

[0052] Preferably, a fume hood 804 is provided above the bar screening device 8, and a fourth fan F4 is connected to the bottom air inlet of the lower hopper 802. The hot air outlet of the fume hood 804 is connected to the air inlet of the wind box 206 provided below the equalizing section 204 through the tenth air duct R10.

[0053] Preferably, the system further comprises a slag crushing device 9. The feeding end of the slag crushing device 9 is connected to the discharging end of the discharge chute 803, and the discharging end of the slag crushing device 9 is connected to the feeding end of the cooler 4 through the crushing chute 901.

[0054] Preferably, the flue gas purification unit 10 comprises a denitration device 1001, a dust collector 1002, a main exhaust fan 1003, a desulfurization device 1004 and a chimney 1005 which are arranged in series. The air inlet of the denitration device 1001 is connected to the hot air outlet of the hot air hood 205 which is arranged on the heat equalization section 204 through the third air duct R3.

[0055] Preferably, the system further comprises a dust collecting device 11 , the feed end of the dust collecting device 11 is connected to the dust discharge end of the dust collector 1002 via a dust conveying pipe 1101 and a dust bin pump 1102 .

[0056] Preferably, the system further comprises a bulk material collecting device 12 , the feed end of the bulk material collecting device 12 being connected to the bulk material outlets of all the bellows 206 via a bulk material belt conveyor 1201 and a bulk material chute 1202 .

[0057] Preferably, the roasting device 2 is a ring roasting machine, and a double-layer ash discharge valve 1203 is independently provided at the bulk material outlet of all wind boxes 206.

[0058] Example 1

[0059] like Figure 1-2 As shown, a phosphate ore pellet roasting and smelting system includes a material distribution mechanism 1, a roasting device 2, a smelting electric furnace 3 and a cooler 4 which are arranged in series. According to the direction of the material, the roasting device 2 includes a drying section 201, a preheating section 202, a roasting section 203 and a soaking section 204. A hot air cover 205 is independently provided above the drying section 201, the preheating section 202, the roasting section 203 and the soaking section 204. A wind box 206 is independently provided below the drying section 201, the preheating section 202, the roasting section 203 and the soaking section 204.

[0060] The hot air inlet of the hot air hood 205 covered on the roasting section 203 is connected to the hot air outlet of the hot air furnace 5 through the first air duct R1. The air outlet of the wind box 206 arranged below the roasting section 203 is connected to the air inlet of the wind box 206 arranged below the equalizing section 204 through the second hot air duct R2. The hot air outlet of the hot air hood 205 covered on the equalizing section 204 is connected to the smoke inlet of the smoke purification unit 10 through the third air duct R3. The hot air outlet of the hot air hood 205 covered on the drying section 201 and the preheating section 202 is connected to the air supply port of the hot air furnace 5 through the fourth air duct R4 and the fifth air duct R5 respectively.

[0061] Example 2

[0062] Example 1 is repeated, except that the distribution mechanism 1 includes a bottom material bin 101, a bottom material distribution device 102, a phosphate ore green pellet conveying device 103, and a phosphate ore green pellet distribution device 104. According to the direction of the material, the bottom material distribution device 102 and the phosphate ore green pellet distribution device 104 are sequentially arranged above the feed end of the roasting device 2. The bottom material bin 101 is arranged above the feed end of the bottom material distribution device 102, and the feed end of the bottom material bin 101 is connected to the discharge end of the natural phosphate ore conveying device 105. The discharge end of the phosphate ore green pellet conveying device 103 is connected to the feed end of the phosphate ore green pellet distribution device 104.

[0063] Example 3

[0064] Example 2 is repeated, except that a gate valve 106 and a bottom material feeding chute 107 are further provided between the bottom material bin 101 and the bottom material distributing device 102.

[0065] Example 4

[0066] Example 3 is repeated, except that the discharge end of the roasting device 2 is further connected to the feed end of the bottom material bin 101 through the return material conveying mechanism 6.

[0067] Example 5

[0068] Example 4 is repeated, except that the return material conveying mechanism 6 includes a high-temperature bucket elevator 601, a high-temperature bucket elevator discharge chute 602, and a return material belt conveyor 603 which are sequentially arranged in series. The discharge end of the roasting device 2 is connected to the feed end of the high-temperature bucket elevator 601 and the feed end of the smelting electric furnace 3 through a three-way distributor 7. The discharge end of the return material belt conveyor 603 is connected to the feed end of the bottom bunker 101.

[0069] Example 6

[0070] Example 5 is repeated, except that the bottom air inlet of the high-temperature bucket elevator 601 is connected to the first fan F1. The top air outlet of the high-temperature bucket elevator 601 is connected to the air supply port of the hot blast furnace 5 through the sixth air duct R6.

[0071] Example 7

[0072] Example 6 is repeated, except that the feed end of the three-way distributor 7 and the discharge end of the roasting device 2 are connected via a high-temperature material guide chute 207.

[0073] Example 8

[0074] Example 7 is repeated, except that the top feed port of the smelting electric furnace 3 is connected to the discharge end of the three-way distributor 7 through the smelting feed chute 301. The bottom slag discharge port of the smelting electric furnace 3 is connected to the feed end of the cooler 4 through the high-temperature slag chute 302. A phosphorus-containing gas collection pipeline 303 is also connected to the upper gas outlet of the smelting electric furnace 3.

[0075] Example 9

[0076] Example 8 is repeated, except that the cooler 4 is a ring cooler. According to the direction of the material, the cooler 4 includes a high temperature section 401, a medium temperature section 402 and a low temperature section 403. The bottom cooling air inlet of the low temperature section 403 is connected to the second fan F2. The top hot air outlet of the low temperature section 403 is connected to the bottom air inlet of the high temperature section 401 through the seventh air duct R7, and the top hot air outlet of the high temperature section 401 is connected to the air inlet of the wind box 206 arranged below the preheating section 202 through the eighth air duct R8. The bottom cooling air inlet of the medium temperature section 402 is connected to the third fan F3, and the top hot air outlet of the medium temperature section 402 is connected to the air inlet of the wind box 206 arranged below the drying section 201 through the ninth air duct R9.

[0077] Example 10

[0078] Example 9 is repeated, except that the system further includes a bar screening device 8. The bar screening device 8 includes screen bars 801 and a lower hopper 802. The lower hopper 802 is arranged below the screen bars 801. The feed end of the screen bars 801 is connected to the bottom slag discharge port of the smelting electric furnace 3 through the high-temperature slag chute 302, and the discharge end of the lower hopper 802 is connected to the feed end of the cooler 4 through the lower chute 803.

[0079] Embodiment 11

[0080] Example 10 is repeated, except that a fume hood 804 is further provided above the strip screening device 8, and the bottom air inlet of the lower hopper 802 is connected to the fourth fan F4. The hot air outlet of the fume hood 804 is connected to the air inlet of the wind box 206 provided below the heat equalizing section 204 through the tenth air duct R10.

[0081] Example 12

[0082] Example 11 is repeated, except that the system further includes a slag crushing device 9. The feed end of the slag crushing device 9 is connected to the discharge end of the discharge chute 803, and the discharge end of the slag crushing device 9 is connected to the feed end of the cooler 4 through the crushing chute 901.

[0083] Example 13

[0084] Example 12 is repeated, except that the flue gas purification unit 10 includes a denitration device 1001, a dust collector 1002, a main exhaust fan 1003, a desulfurization device 1004 and a chimney 1005 arranged in series. The air inlet of the denitration device 1001 is connected to the hot air outlet of the hot air hood 205 covered on the heat equalization section 204 through the third air duct R3.

[0085] Embodiment 14

[0086] Example 13 is repeated, except that the system further includes a dust collecting device 11 , and the feed end of the dust collecting device 11 is connected to the dust discharge end of the dust collector 1002 via a dust conveying pipe 1101 and a dust bin pump 1102 .

[0087] Embodiment 15

[0088] Example 14 is repeated, except that the system further includes a bulk material collecting device 12, and the feed end of the bulk material collecting device 12 is connected to the bulk material outlets of all the air boxes 206 through a bulk material belt conveyor 1201 and a bulk material chute 1202.

[0089] Example 16

[0090] Example 15 is repeated, except that the roasting device 2 is a ring roasting machine, and double-layer ash discharge valves 1203 are independently provided at the bulk material outlets of all wind boxes 206.

Claims

1. A phosphate ore pellet roasting and smelting system, characterized by: The system comprises a material distribution mechanism (1), a roasting device (2), a smelting electric furnace (3) and a cooler (4) which are sequentially arranged in series; according to the direction of the material, the roasting device (2) comprises a drying section (201), a preheating section (202), a roasting section (203) and a soaking section (204); a hot air cover (205) is independently provided above the drying section (201), the preheating section (202), the roasting section (203) and the soaking section (204); and a wind box (206) is independently provided below the drying section (201), the preheating section (202), the roasting section (203) and the soaking section (204); The hot air inlet of the hot air hood (205) arranged on the roasting section (203) is connected to the hot air outlet of the hot air furnace (5) through the first air duct (R1); the air outlet of the wind box (206) arranged below the roasting section (203) is connected to the air inlet of the wind box (206) arranged below the equalizing section (204) through the second hot air duct (R2); the hot air outlet of the hot air hood (205) arranged on the equalizing section (204) is connected to the smoke inlet of the smoke purification unit (10) through the third air duct (R3); the hot air outlet of the hot air hood (205) arranged on the drying section (201) and the preheating section (202) is connected to the air supply port of the hot air furnace (5) through the fourth air duct (R4) and the fifth air duct (R5), respectively.

2. The system according to claim 1, characterized in that: The material distribution mechanism (1) comprises a bottom material bunker (101), a bottom material distribution device (102), a phosphate ore green pellet conveying device (103) and a phosphate ore green pellet distribution device (104); according to the direction of the material, the bottom material distribution device (102) and the phosphate ore green pellet distribution device (104) are sequentially arranged above the feed end of the roasting device (2); the bottom material bunker (101) is arranged above the feed end of the bottom material distribution device (102), and the feed end of the bottom material bunker (101) is connected to the discharge end of the natural phosphate ore conveying device (105); the discharge end of the phosphate ore green pellet conveying device (103) is connected to the feed end of the phosphate ore green pellet distribution device (104).

3. The system according to claim 2, characterized in that: A gate valve (106) and a bottom material feeding chute (107) are also provided between the bottom material bin (101) and the bottom material distributing device (102).

4. The system according to claim 2, characterized in that: The material discharge end of the roasting device (2) is also connected to the material feed end of the bottom material bin (101) via a material return conveying mechanism (6).

5. The system according to claim 4, characterized in that: The return material conveying mechanism (6) comprises a high-temperature bucket elevator (601), a high-temperature bucket elevator discharge chute (602) and a return material belt conveyor (603) which are arranged in series in sequence; the discharge end of the roasting device (2) is connected to the feed end of the high-temperature bucket elevator (601) and the feed end of the smelting electric furnace (3) through a three-way distributor (7); the discharge end of the return material belt conveyor (603) is connected to the feed end of the bottom bunker (101).

6. The system according to claim 5, characterized in that: The bottom air inlet of the high-temperature bucket elevator (601) is connected to the first fan (F1); the top air outlet of the high-temperature bucket elevator (601) is connected to the air supply port of the hot air furnace (5) through the sixth air duct (R6).

7. The system according to claim 6, characterized in that: The feeding end of the three-way distributor (7) and the discharging end of the roasting device (2) are connected via a high-temperature material guide chute (207).

8. The system according to claim 5, characterized in that: The top feed port of the smelting electric furnace (3) is connected to the discharge end of the three-way distributor (7) through the smelting feed chute (301); the bottom slag discharge port of the smelting electric furnace (3) is connected to the feed end of the cooler (4) through the high-temperature slag chute (302); and a phosphorus-containing gas collection pipeline (303) is also connected to the upper gas outlet of the smelting electric furnace (3).

9. The system according to any one of claims 1 to 8, characterized in that: The cooler (4) is a ring cooler. According to the direction of the material, the cooler (4) includes a high-temperature section (401), a medium-temperature section (402) and a low-temperature section (403); the bottom cooling air inlet of the low-temperature section (403) is connected to the second fan (F2); the top hot air outlet of the low-temperature section (403) is connected to the bottom air inlet of the high-temperature section (401) through the seventh air duct (R7), and the top hot air outlet of the high-temperature section (401) is connected to the air inlet of the wind box (206) arranged below the preheating section (202) through the eighth air duct (R8); the bottom cooling air inlet of the medium-temperature section (402) is connected to the third fan (F3), and the top hot air outlet of the medium-temperature section (402) is connected to the air inlet of the wind box (206) arranged below the drying section (201) through the ninth air duct (R9).

10. The system according to any one of claims 1 to 8, characterized in that: The system also includes a bar screening device (8); the bar screening device (8) includes screen bars (801) and a lower hopper (802); the lower hopper (802) is arranged below the screen bars (801); the feed end of the screen bars (801) is connected to the bottom slag discharge port of the smelting electric furnace (3) through a high-temperature slag chute (302), and the discharge end of the lower hopper (802) is connected to the feed end of the cooler (4) through a lower chute (803).

11. The system according to claim 10, characterized in that: A fume hood (804) is also provided above the bar screening device (8), and the bottom air inlet of the lower hopper (802) is connected to a fourth fan (F4); the hot air outlet of the fume hood (804) is connected to the air inlet of a wind box (206) provided below the equalizing section (204) through a tenth air duct (R10).

12. The system according to claim 10, characterized in that: The system also includes a slag crushing device (9); the feed end of the slag crushing device (9) is connected to the discharge end of the discharge chute (803), and the discharge end of the slag crushing device (9) is connected to the feed end of the cooler (4) through the crushing chute (901).

13. The system according to any one of claims 1 to 8, characterized in that: The flue gas purification unit (10) comprises a denitration device (1001), a dust collector (1002), a main exhaust fan (1003), a desulfurization device (1004) and a chimney (1005) which are arranged in series in sequence; the air inlet of the denitration device (1001) is connected to the hot air outlet of a hot air hood (205) arranged on the heat equalization section (204) through a third air duct (R3).

14. The system according to claim 13, characterized in that: The system further comprises a dust collecting device (11), wherein a feeding end of the dust collecting device (11) is connected to a dust discharging end of a dust collector (1002) via a dust conveying pipeline (1101) and a dust bin pump (1102); and / or The system also includes a bulk material collecting device (12), the feed end of which is connected to the bulk material outlets of all the bellows (206) via a bulk material belt conveyor (1201) and a bulk material chute (1202).

15. The system according to claim 14, characterized in that: The roasting device (2) is a ring-type roasting machine, and a double-layer ash discharge valve (1203) is independently provided at the bulk material outlet of all wind boxes (206).

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