Oxygen-enriched side-blown smelting system for extracting phosphorus from phosphorus-containing material
Through the oxygen-rich side blowing smelting system, the problem of high energy consumption and high investment in medium and low grade phosphate ores is solved, and the preparation of high-purity phosphoric acid is achieved with low energy consumption and efficient preparation of high-purity phosphoric acid, simplifying equipment investment, and improving thermal efficiency and environmental protection.
Patent Information
- Application Number
- CN202422223926.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-11
- Publication Date
- 2025-07-08
- Estimated Expiration
- 2034-09-11
AI Technical Summary
The existing technology has high energy consumption, large investment and serious pollution when efficiently utilizing medium and low-grade phosphate ores. In particular, the electric energy consumption is large during the process of phosphorus refining of electric furnaces and blast furnaces, and the gas is generated and the flow rate is high, resulting in high system energy consumption and large equipment investment.
The oxygen-rich side blowing and smelting system is adopted, including one or two oxygen-rich side blowing furnaces, and the smelting zone and electric heating zone are set up. Multi-layer spray guns and electrodes are used to provide heating. High-purity phosphoric acid is prepared through flue gas purification devices and adsorption towers to reduce equipment investment, improve thermal efficiency, and reduce energy consumption.
It realizes low-energy consumption and efficient preparation of phosphoric acid, reduces equipment investment, is environmentally friendly, and can be completed in steps through two furnaces when the processing volume is large. The CO and CO2 content in the exhaust gas is high, and the energy utilization rate is high, so high quality phosphoric acid is prepared.
Smart Images
Figure CN223077388U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of phosphoric acid preparation, and particularly relates to an oxygen-enriched side-blown smelting system for extracting phosphorus from phosphorus-containing materials. Background Art
[0002] According to the grade classification of phosphate rock, phosphate rock with a phosphate rock grade (P2O5 content) > 30% is grade I phosphate rock, that is, high-grade phosphate rock, 25% < P2O5 < 30% is grade II phosphate rock, and 12% < P2O5 < 25% is grade III phosphate rock. Phosphate rock is the raw material for producing phosphate fertilizer and phosphate, and is an important non-renewable strategic resource. High-grade phosphate rock has been over-exploited and is facing exhaustion. Making full use of medium and low-grade phosphate rock is the key to the sustainable and efficient utilization of phosphorus resources. The phosphate rock grade in China is generally low, only about 10% of the phosphate rock has a grade exceeding 30%, and about 90% of the phosphate rock is medium and low-grade phosphate rock with a grade less than 25%.
[0003] The waste lithium iron phosphate contains a relatively high P2O5 and is stockpiled as waste.
[0004] The methods for producing phosphoric acid mainly include two types: wet process and thermal process. Among them, phosphoric acid made by treating phosphate rock with sulfuric acid and other inorganic acids is wet-process phosphoric acid, and phosphoric acid obtained by producing elemental phosphorus with an electric furnace or a blast furnace and then burning and hydrating is called thermal-process phosphoric acid. Thermal-process phosphoric acid has less pollution and higher purity compared to wet-process phosphoric acid, can effectively utilize low-grade phosphate rock and can be further used to prepare food-grade phosphoric acid and electronic-grade phosphate products, with a wide application range and an increasing market demand. However, at present, the power consumption for phosphorus smelting in an electric furnace is large. In China, electric energy mainly comes from thermal power, and the conversion rate of coal power is only about 30%. This is not only an energy conversion process but also an energy-consuming process. For phosphorus smelting by the blast furnace method, a sintering plant, a pelletizing plant, and a coking plant need to be supported, resulting in a greatly increased total investment. Also, due to air blowing, there is more air blowing, a large gas volume, a high flow rate, an increase in the furnace dust carried out, and a large amount of gas produced. Summary of the Utility Model
[0005] The main purpose of the utility model is to provide an oxygen-enriched side-blown smelting system for extracting phosphorus from phosphorus-containing materials to solve the above problems.
[0006] To achieve the above object, the utility model provides an oxygen-enriched side-blown smelting system for extracting phosphorus from phosphorus-containing materials, including one or two oxygen-enriched side-blown furnaces. The oxygen-enriched side-blown furnace includes a molten bath and a furnace body. A charging port and a flue gas outlet are arranged at the top of the furnace body. The side wall of the furnace body is provided with multiple upper and lower layers of spray guns. The spray guns in the lower layer are located below the molten liquid surface, and the spray guns in the upper layer are located above the molten liquid surface and close to the flue gas outlet. The flue gas outlet is sequentially connected with a flue gas purification device and an adsorption tower through pipelines. A slag discharge port and a metal discharge port are arranged on the molten bath.
[0007] When there is only one oxygen-enriched side-blown furnace, the molten bath includes a smelting area and an electrothermal area. The furnace body is arranged above the smelting area, and a channel for connecting the smelting area and the electrothermal area is arranged at the bottom of the furnace body; the slag discharge port and the metal discharge port are communicated with the electrothermal area;
[0008] When there are two oxygen-enriched side-blown furnaces, the two oxygen-enriched side-blown furnaces are arranged with one high and one low. The slag discharge port of the oxygen-enriched side-blown furnace at the higher position is higher than the feeding port of the oxygen-enriched side-blown furnace at the lower position, and the slag discharge port of the oxygen-enriched side-blown furnace at the higher position is connected to the feeding port of the oxygen-enriched side-blown furnace at the lower position through a hot molten liquid chute.
[0009] Furthermore, at least one electrode is arranged in the electrothermal area, and the end of the electrode is located below the molten liquid surface in the electrothermal area for heating and heat preservation of the molten liquid.
[0010] Furthermore, the height of the bottom of the smelting area is higher than the height of the bottom of the electrothermal area, and the height difference is 200 - 600 mm.
[0011] Furthermore, the flue gas outlets of the two oxygen-enriched side-blown furnaces are both connected to the flue gas purification device.
[0012] The utility model has the following beneficial effects:
[0013] The utility model does not need to be equipped with a sintering plant, a pelletizing plant and a coking plant, and has the advantages of less investment, short process, more environmental protection, low energy consumption, etc. The smelting and reduction processes can be completed in one step in the same oxygen-enriched side-blown smelting furnace. When the processing capacity is large, it can also be completed in two steps in two oxygen-enriched side-blown smelting furnaces. The heat released by the reaction is used to improve the thermal efficiency of the oxygen-enriched side-blown smelting furnace. There is no CO in the tail gas, the CO2 content is high, and the energy utilization rate is very high. By replacing electricity with coal and replacing coke with coal, the total system energy consumption is greatly reduced. The purified flue gas is absorbed by the absorption tower, and high-quality and high-purity phosphoric acid can be obtained. Description of the Drawings
[0014] Figure 1 It is a schematic diagram of a single oxygen-enriched side-blown furnace of an oxygen-enriched side-blown smelting system for extracting phosphorus from phosphorus-containing materials proposed by the utility model;
[0015] Figure 2 It is another schematic diagram of a single oxygen-enriched side-blown furnace of an oxygen-enriched side-blown smelting system for extracting phosphorus from phosphorus-containing materials proposed by the utility model;
[0016] Figure 3 It is a schematic diagram of two oxygen-enriched side-blown furnaces of an oxygen-enriched side-blown smelting system for extracting phosphorus from phosphorus-containing materials proposed by the utility model.
[0017] In the figure: 1 - smelting area; 2 - channel; 3 - electrothermal area; 4 - lance; 5 - feeding port; 6 - flue gas outlet; 7 - electrode; 8 - hot molten liquid chute. Detailed implementation mode
[0018] To achieve the above-mentioned purpose and effect, the technical means and structure adopted by the present utility model will be described in detail in combination with the drawings for the preferred embodiments of the present utility model to illustrate its features and functions.
[0019] As Figures 1 - 3 shown, the present utility model provides an oxygen-enriched side-blowing smelting system for extracting phosphorus from phosphorus-containing materials, including one or two oxygen-enriched side-blowing furnaces. The oxygen-enriched side-blowing furnace includes a molten pool and a furnace body. A charging port 5 and a flue gas outlet 6 are arranged at the top of the furnace body. Multiple layers of spray guns 4 are arranged on the side wall of the furnace body. The lower spray guns 4 are located below the molten liquid surface, and the upper spray guns 4 are located above the molten liquid surface and close to the flue gas outlet 6. The flue gas outlet 6 is sequentially connected with a flue gas purification device and an adsorption tower through pipelines. A slag discharge port and a metal discharge port are arranged on the molten pool.
[0020] As Figures 1 - 2 shown, when there is only one oxygen-enriched side-blowing furnace, the molten pool includes a smelting area 1 and an electrothermal area 3. The furnace body is arranged above the smelting area 1, and a channel 2 for connecting the smelting area 1 and the electrothermal area 3 is arranged at the bottom of the furnace body. The slag discharge port and the metal discharge port are communicated with the electrothermal area 3. At least one electrode 7 is arranged in the electrothermal area, and the end of the electrode 7 is located below the molten liquid surface in the electrothermal area 3 for heating and insulating the molten liquid. The height of the bottom of the smelting area 1 is higher than the height of the bottom of the electrothermal area 3, and the height difference is 200 - 600 mm to increase the slag storage time and facilitate the separation of metal and molten slag.
[0021] As Figure 3 shown, when there are two oxygen-enriched side-blowing furnaces, the two oxygen-enriched side-blowing furnaces are arranged at different heights. The slag discharge port of the oxygen-enriched side-blowing furnace at the higher position is higher than the charging port 5 of the oxygen-enriched side-blowing furnace at the lower position, and the slag discharge port of the oxygen-enriched side-blowing furnace at the higher position is connected with the charging port 5 of the oxygen-enriched side-blowing furnace at the lower position through a hot molten liquid delivery chute 8. The flue gas outlets 6 of the two oxygen-enriched side-blowing furnaces are both connected with the flue gas purification device, and the flue gases generated in the two processes can also be mixed for treatment, reducing the investment in the flue gas purification device.
[0022] Phosphorus-containing materials such as phosphate rock, granular coal, fluxes, etc. are added from the charging port 5 of the oxygen-enriched side-blown smelting furnace in a certain proportion. Pulverized coal and oxygen-enriched air are blown into the molten bath from the lance 4 at the lower layer on the side of the oxygen-enriched side-blown smelting furnace. Part of the oxygen oxidizes C and P in the materials to produce CO and P2O5 gases, and part of the oxygen directly burns the coal. At the slag-iron interface of the molten bath, C in the molten iron continuously reduces calcium phosphate in the slag. Part of the pulverized coal sprayed into the molten bath burns directly with oxygen, and part directly enters the molten iron to carburize the molten iron, thereby supplementing the C consumed by the molten iron for reducing calcium phosphate and a small amount of iron oxides in the slag. In order to improve the heating intensity and energy utilization rate, oxygen-enriched air is sprayed from the lance 4 at the upper layer on the side of the oxygen-enriched side-blown smelting furnace for secondary combustion of the gas, oxidizing the reduced product elemental P to P2O5 gas. The flue gas discharged from the flue gas outlet 6 of the oxygen-enriched side-blown furnace is purified by a flue gas purification device, and then P2O5 is absorbed by the absorption tower and dissolved in water to make phosphoric acid.
[0023] When the processing capacity is small, the melting and partial reduction process and the reduction smelting process can be carried out in the same oxygen-enriched side-blown furnace. When the processing capacity is large, the melting and partial reduction process and the reduction smelting process can be carried out in two oxygen-enriched side-blown furnaces respectively. The electric heating zone or the second oxygen-enriched side-blown smelting furnace can also maintain a relatively high temperature by using the heat of the molten liquid, reducing the power consumption during separate reduction and impoverishment.
[0024] The above description is only the preferred embodiment of the present invention, not all embodiments. Anyone should know that structural changes made under the inspiration of the present invention, as long as they have the same or similar technical solutions as the present invention, all belong to the protection scope of the present invention.
Claims
1. An oxygen-enriched side-blowing smelting system for extracting phosphorus from phosphorus-containing materials, characterized in that, It includes one or two oxygen-enriched side-blown furnaces. The oxygen-enriched side-blown furnace includes a molten bath and a furnace body. A charging port and a flue gas outlet are arranged at the top of the furnace body. Multiple upper and lower layers of lances are arranged on the side wall of the furnace body. The lower lances are located below the molten liquid surface, and the upper lances are located above the molten liquid surface and close to the flue gas outlet. The flue gas outlet is sequentially connected with a flue gas purification device and an adsorption tower through pipelines. A slag discharge port and a metal discharge port are arranged on the molten bath. When there is only one oxygen-enriched side-blown furnace, the molten bath includes a smelting area and an electrothermal area. The furnace body is arranged above the smelting area, and a channel for connecting the smelting area and the electrothermal area is arranged at the bottom of the furnace body. The slag discharge port and the metal discharge port are communicated with the electrothermal area. When there are two oxygen-enriched side-blown furnaces, the two oxygen-enriched side-blown furnaces are arranged with one high and one low. The slag discharge port of the oxygen-enriched side-blown furnace at the higher position is higher than the charging port of the oxygen-enriched side-blown furnace at the lower position, and a hot metal conveying chute is connected between the slag discharge port of the oxygen-enriched side-blown furnace at the higher position and the charging port of the oxygen-enriched side-blown furnace at the lower position through molten liquid.
2. The oxygen-enriched side-blowing smelting system for extracting phosphorus from phosphorus-containing materials as described in claim 1, wherein At least one electrode is arranged in the electrothermal area, and the end of the electrode is located below the molten liquid surface in the electrothermal area for heating and insulating the molten liquid.
3. An oxygen-enriched side-blowing smelting system for extracting phosphorus from phosphorus-containing materials as described in claim 1, characterized in that, The height of the bottom of the smelting area is higher than the height of the bottom of the electrothermal area, and the height difference is 200 - 600 mm.
4. The oxygen-enriched side-blown smelting system for extracting phosphorus from phosphorus-containing materials according to claim 1, wherein The flue gas outlets of the two oxygen-enriched side-blown furnaces are both connected with the flue gas purification device.