CN113249566B - Sintering system and method for limonite type laterite-nickel ore - Google Patents

Abstract

The invention belongs to the technical field of iron ore sintering and energy saving and emission reduction, and in particular relates to a sintering system and method of limonite-type laterite nickel ore. In the method, limonite-type laterite nickel ore, quicklime, dedusting ash, etc. are mixed in a certain proportion, mixed vigorously, added with water, mixed evenly, and granulated. First spread a layer of sintered ore on the trolley as the base material, and then spread the sinter mixture evenly on the trolley. At the same time, lay a layer of sinter side material between the sinter mixture and the side plate of the trolley, and through the circulation of the trolley, the sinter mixture is dried, preheated, sintered, cooled, and then processed under the action of hot air at different temperatures. Crushed and sieved. The invention has fast sintering speed and low fuel consumption, and can effectively improve the traditional sintering problems of high ore return, low drum and high fuel consumption of limonite-type laterite nickel ore containing high crystal water in traditional sintering. The use of gas fuel for heating makes the overall process clear and controllable.

Description

A kind of sintering system and method of limonite type laterite nickel ore

technical field

The invention belongs to the technical field of iron ore sintering and energy saving and emission reduction, and in particular relates to a sintering system and method of limonite-type laterite nickel ore.

Background technique

The particle size of laterite nickel ore is too fine, it must be artificially agglomerated, and can only be smelted in a blast furnace after reaching a certain particle size. It has many smelting performances superior to those of natural lump ore, and has sufficient alkalinity, and slag is made in advance. In the subsequent blast furnace smelting process, less or even no flux can be added, which can remove impurities, improve the quality of ore materials, and change Ore phase structure and metallurgical properties, currently the most widely used blast furnace smelting method for laterite nickel ore is sintering.

For the limonite-type laterite-nickel ore of oxidized ore, the general characteristic of the industry is that the surface water content is high. In addition to the surface water, there are also crystal water and hydroxyl water, and the total amount is more than 30%. Moreover, limonite-type lateritic nickel ore is a hydrophilic substance. In the mixing process, in order to ensure effective granulation moisture, it is often necessary to add more water, which is inconsistent with the actual production requirements, and the excessive moisture leads to the actual production. In the laterite nickel ore, it is necessary to dry the laterite nickel ore before the raw material batching. According to the thermogravimetric analysis in the reference, the limonite type laterite nickel ore needs to be dried at 850-900°C for two hours before it can be completely dried, and the dried laterite nickel ore Nickel ore is easy to agglomerate, and the particle size is extremely fine, which can account for more than 60% under the 400 mesh sieve. Based on the existing conditions, the water treatment in the laterite nickel ore has become one of the keys to improve the quality of sintering production.

Compared with ordinary carbon steel sintering, the difference is that for laterite nickel ore, especially limonite-type laterite nickel ore, it is not suitable for acidic pellets. In the stainless steel industry, the common blast furnace ore mix structure That is, more than 80% of sintered ore and about 10% of lump ore and fuel enter the blast furnace.

Therefore, the high alkalinity, high temperature and standard configuration of increasing the liquid phase content of calcium ferrite in ordinary carbon steel sintering are not common in laterite nickel ore sintering in the stainless steel industry. The common laterite nickel ore sintering alkalinity is 1.5, due to high Moisture, high fuel consumption caused by high fuel, and relatively low combustion temperature are not enough to support the liquid phase to change into calcium ferrite in a large amount but exist in the form of fayalite. In actual production, the alkalinity is difficult to meet expectations. value.

To sum up, compared with ordinary carbon steel sintering, laterite nickel ore sintering still has many technical problems to be solved, and the technical indicators of ordinary carbon steel sintering cannot be simply applied to laterite nickel ore sintering.

Contents of the invention

In order to solve the deficiencies of the prior art, the invention provides a sintering system and method of limonite-type lateritic nickel ore.

The technical scheme provided by the present invention is as follows:

A sintering system of limonite-type lateritic nickel ore, comprising:

Batching device, strong mixing device, granulating device, screening device and distribution device for batching, mixing, granulating, screening and distributing of raw materials in sequence;

Belt sintering device for sintering cloth;

As well as the crushing device, vibrating screen and temporary finished product silo for crushing, screening and product collection of the sintered material in sequence.

Based on the sintering system of limonite-type laterite-nickel ore provided by the above-mentioned technical scheme, limonite-type laterite-nickel ore can be sintered.

Specifically, the belt sintering device includes:

Blast drying section, exhaust drying section, preheating section, sintering section, soaking section, first cooling section and second cooling section are connected in sequence, and the first cooling section has a first air inlet at its lower part and the first hot air outlet on its upper part, the second cooling section has a second air inlet on its lower part and a second hot air outlet on its upper part, and the heat equalization section has a third outlet on its lower part The hot air outlet, the sintering section has a fourth hot air inlet located at its upper part and a fourth hot air outlet located at its lower part, and the preheating section has a fifth hot air inlet located at its upper part and a fifth hot air outlet located at its lower part The hot air outlet, the draft drying section has the sixth hot air inlet located at its upper part and the sixth hot air outlet located at its lower part, the blast drying section has the seventh lower hot air inlet located at its lower part, and the sixth hot air outlet located at its lower part. The seventh hot air outlet on the upper part, wherein the first hot air outlet is connected to the fourth hot air inlet, the second hot air outlet is connected to the seventh lower hot air inlet through a blower, and the first hot air outlet is connected to the fourth hot air inlet. The three hot air outlets and the fourth hot air outlet are respectively connected to a heat recovery fan, and the heat recovery fan is respectively connected to the fifth hot air inlet and the sixth hot air inlet;

And a burner device for heating the preheating section and the sintering section.

Based on the above technical solution, the waste heat in the sintering section, the soaking section, the first cooling section and the second cooling section can be fully utilized.

Further, a conveying mechanism is provided below the screening device for transporting the screened materials to the intensive mixing device.

Based on the above technical solution, the fine particle material screened out by the screening device can be returned and re-mixed vigorously.

Further, the distributing device is a multi-roller distributing machine, and a conveying mechanism is arranged below it, which is used to transport materials whose particle size is not large enough to the intensive mixing device.

Based on the above-mentioned technical scheme, the fine particle material screened out by the sieve plate can be returned and re-mixed vigorously.

Further, the system also includes an electric precipitator, an exhaust fan, and a smoke exhaust pipe connected in sequence, the sixth hot air outlet and/or the fifth hot air outlet are connected to the electric precipitator, and/or all A dust outlet is provided before the blast drying section, and the dust outlet is connected to the electrostatic precipitator.

Based on the above technical solution, the exhaust gas can be dedusted and discharged.

Further, the system also includes a bottom-laying device for laying bottom-laying material on the belt sintering device, and the vibrating screen is provided with a conveying mechanism for transporting the undersize to the bottom-laying device.

Based on the above technical solution, the materials screened out by the vibrating screen can be returned for spreading.

The present invention also provides a sintering method of limonite-type laterite-nickel ore, using the above-mentioned sintering system of limonite-type laterite-nickel ore for sintering, specifically, using gaseous fuel as the fuel for the burner device to The hot section and the sintering section are heated.

Based on the above technical scheme, the use of gas fuel for heating makes the overall process clear and controllable, avoiding the simultaneous occurrence of under-burning and over-melting of sintered ore, and avoiding the problem of limonite-type lateritic nickel ore itself being hydrophilic and containing a large amount of Minerals of crystallization water will appear collapse, cracks and other phenomena during traditional sintering.

Specifically, the iron ore-type laterite-nickel ore, quicklime, limestone and dolomite are batched by a batching device, and the obtained batching satisfies the alkalinity of 0.8-1.7.

Specifically, the screened material with a particle size below 5 mm is transported back to the intensive mixing device through a conveying mechanism provided below the screening device.

Specifically, the material with a particle size below 5 mm is transported back to the intensive mixing device through the conveying mechanism provided under the multi-roller distribution machine.

Specifically, a layer of sintered ore with a thickness of 30-80 mm and a particle size of 10-25 mm is first laid on the trolley of the belt-type sintering device as the base material, and then the sintered mixture is evenly arranged on the trolley through a multi-roller distribution machine , the cloth height is 200-500mm, the particle size is more than 5mm, and a layer of sintered ore side material with a thickness of 20-60mm and a particle size of 10-25mm is laid between the sintering mixture and the side plate of the trolley, and then sintered. The base material can be laid manually.

Based on the above technical scheme, the material layer is relatively thin, with good air permeability and high sintering efficiency.

Specifically, in the blast drying section, the temperature of the hot air entering from the seventh downward hot air inlet is 100-300° C., and the air flow passes through the material bed from bottom to top; the residence time of the material bed is 10-30 min.

Based on the above technical scheme, the excess water in the limonite-type laterite-nickel ore should be eliminated as much as possible, and the high return rate of limonite-type laterite-nickel ore with high crystallization water will be avoided during traditional sintering. Low strength, high fuel consumption and other problems and maintain sinter production.

Specifically, in the air extraction and drying section, the temperature of the hot air entering through the sixth hot air inlet is 300-600° C., and the air flow passes through the material layer from top to bottom; the residence time of the material layer is 10-30 minutes.

Based on the above technical scheme, the excess water in the limonite-type laterite-nickel ore should be eliminated as much as possible, and the high return rate of limonite-type laterite-nickel ore with high crystallization water will be avoided during traditional sintering. Low strength, high fuel consumption and other problems and maintain sinter production.

Specifically, in the preheating section, the hot air entering the fifth hot air inlet and the burner device will heat the inside to a preheating temperature of 900-1150°C; the preheating time of the material layer is 10-30min .

Specifically, in the sintering section, the hot air entering the fourth hot air inlet and the burner device heats the inside to 1250-1350° C.; the sintering time of the material layer is 12-30 minutes.

Specifically, in the soaking section, the temperature is 750-850° C.; the soaking time of the material layer is 3-5 minutes.

Specifically, in the first cooling section, the cooling medium is natural air, and the airflow direction passes through the material bed from bottom to top; the cooling time of the material bed is 12-20 minutes.

Specifically, in the second cooling section, the cooling medium is natural air, and the airflow direction passes through the material bed from bottom to top; the cooling time of the material bed is 4-15 minutes.

The invention mixes iron ore powder, quicklime, limestone and dolomite according to a certain proportion, adds water to mix and granulate, and does not add solid fuel during the batching process; no fuel in any form is added to the sintering mixture, and the sintering The process is integrated on the belt-type sintering machine to carry out the above-mentioned sintering process on the mixture by using the high-temperature hot air generated by the combustion of gas fuel injected by the burners on both sides of the trolley. By setting the drum drying section and the drying section of the belt sintering machine, and the material layer is thin, the air permeability is good, and the sintering efficiency is high, the excess water in the limonite-type lateritic nickel ore is eliminated as much as possible, and the high temperature is also avoided. Limonite-type laterite-nickel ore with crystalline water will have problems such as high return rate, low sintering strength, and high fuel consumption during traditional sintering, and the sinter output will be maintained. At the same time, the hot air circulation in the belt sintering machine is energy-saving and environmentally friendly, and the concentration of pollutants is low. Depending on the gas fuel, a completely carbon-free sintering process can be carried out.

Description of drawings

Fig. 1 is a system diagram of the sintering system of iron ore type laterite nickel ore provided by the present invention.

In accompanying drawing 1, the structural list represented by each label is as follows:

1. Batching device, 2. Intensive mixing device, 3. Granulating device, 4. Screening device, 5. Distributing device, 6. Crushing device, 7. Vibrating screen, 8. Temporary finished product silo, 9. Blast Drying section, 10, exhaust drying section, 11, preheating section, 12, sintering section, 13, soaking section, 14, first cooling section, 15, second cooling section, 16, electrostatic precipitator, 17, exhaust fan , 18, smoke exhaust pipe, 19, bottom material device.

Detailed ways

The principles and features of the present invention are described below, and the examples given are only used to explain the present invention, and are not intended to limit the scope of the present invention.

It should be noted that when a part or component is said to be "connected", "located on", "assembled" on another part or component, it may be set directly on the other part or component or may be present at the same time. parts and assemblies. The terms "left", "right", "upper", "lower" and similar expressions are used herein for the purpose of description only.

In a specific embodiment, as shown in Figure 1, the sintering system of limonite-type lateritic nickel ore includes: a batching device 1 for sequentially batching, mixing, granulating, screening and distributing raw materials, and an intensive mixing device 2 , granulation device 3, screening device 4 and material distribution device 5; belt sintering device for sintering the cloth; and crushing device 6, vibrating screen 7 and temporary storage of finished products for sequentially crushing, screening and collecting the sintered material Silo 8. Based on the sintering system of limonite type laterite nickel ore provided by this technical scheme, limonite type laterite nickel ore can be sintered.

In one embodiment, as shown in Figure 1, the belt sintering device includes: a blast drying section 9, a draft drying section 10, a preheating section 11, a sintering section 12, a soaking section 13, a A cooling section 14 and a second cooling section 15, the first cooling section 14 has a first air inlet located at its lower part and a first hot air outlet located at its upper part, and the second cooling section 15 has a first air outlet located at its lower part The second air inlet and the second hot air outlet located on its upper part, the heat soaking section 13 has a third hot air outlet located on its lower part, and the sintering section 12 has a fourth hot air inlet located on its upper part and a fourth hot air outlet located on its upper part. The fourth hot air outlet at its lower part, the preheating section 11 has a fifth hot air inlet located at its upper part and a fifth hot air outlet located at its lower part, and the suction drying section 10 has a sixth air inlet located at its upper part The hot air outlet and the sixth hot air outlet located at its lower part, the blast drying section 9 has the seventh lower hot air inlet located at its lower part, and the seventh hot air outlet located at its upper part, wherein the first hot air outlet The fourth hot air inlet is connected to the fourth hot air inlet, the second hot air outlet is connected to the seventh lower hot air inlet through the blower, and the third hot air outlet and the fourth hot air outlet are respectively connected to the heat recovery A fan, the reheating fan communicates with the fifth hot air inlet and the sixth hot air inlet respectively; and a burner device for heating the preheating section 11 and the sintering section 12 . Based on this technical solution, the waste heat in the sintering section, the soaking section, the first cooling section and the second cooling section can be fully utilized.

In one embodiment, as shown in FIG. 1 , a conveying mechanism is provided below the screening device 4 for transporting the screened materials to the intensive mixing device 2 . Based on this technical solution, the fine particle material screened out by the screening device can be returned for strong mixing again.

In one embodiment, as shown in FIG. 1 , the distributing device 5 is a multi-roller distributing machine, and a conveying mechanism is arranged below it for conveying materials whose particle size is not large enough to the intensive mixing device 2 . Based on this technical solution, the fine particle material screened out by the sieve plate can be returned for strong mixing again.

In one embodiment, as shown in FIG. 1 , the system further includes an electric dust collector 16, an exhaust fan 17 and a smoke exhaust pipe 18 connected in sequence, and the sixth hot air outlet communicates with the electric dust collector 16, or, A dust outlet is provided before the blast drying section 9 , and the dust outlet is connected to the electrostatic precipitator 16 . Based on this technical solution, the exhaust gas can be dedusted and discharged.

In one embodiment, as shown in FIG. 1 , the system also includes a bottom-laying device 19 for laying bottom material on the belt sintering device. the transmission mechanism. Based on this technical solution, the materials screened out by the vibrating screen can be returned for spreading.

Example 1

Mix limonite-type laterite-nickel ore, quicklime, limestone, and dolomite so that the alkalinity is 1.5, mix vigorously, add water to mix, and granulate. First lay a layer of sintered ore with a thickness of 35mm and a particle size of 10-25mm on the trolley as the base material, and then distribute the sintered mixture evenly on the trolley with a cloth height of 300mm and a particle size of 5-10mm. At the same time, lay a layer of sinter side material with a thickness of 25mm and a particle size of 10-25mm between the sintering mixture and the side plate of the trolley, and run through the circulation of the trolley. The sintered mixture is sequentially dried, preheated, sintered, cooled, and then crushed and screened under the action of hot air at different temperatures.

The blast drying hot air comes from the medium-temperature flue gas in the second cooling stage and the second half of sintering, the temperature is 120°C, and the airflow passes through the material bed from bottom to top.

The hot air for extraction and drying comes from the medium-temperature flue gas and the combustion system in the cooling stage and the second half of the sintering stage. The temperature is 350 ° C. The air flow passes through the material bed from top to bottom. The total time of blast drying and exhaust drying is 20 minutes.

The preheating process is exhaust preheating. The preheating hot air comes from the burner system, the medium-high temperature flue gas in the second half of the sintering and the high-temperature flue gas in the first cold section. The preheating temperature is 900°C. The time is 15 minutes.

The sintering process is draft sintering, the sintering hot air comes from the combustion system and the high-temperature flue gas in the cooling section, the sintering temperature is 1300°C, and the sintering time is 12 minutes.

In the soaking section, the temperature is 750° C.; the soaking time of the material layer is 3 minutes.

The cooling medium of the primary cooling is natural air, and the air flow direction passes through the material layer from bottom to top, and the cooling time is 12 minutes. The medium of secondary cooling is natural air, and the air flow direction passes through the material layer from bottom to top, and the cooling time is 5min.

The finished sintered ore is obtained, the finished product rate is 85%, and the drum is 70%. Compared with the traditional belt draft sintering, the energy consumption of the sintering process of the present invention is reduced by 55%, the carbon dioxide emission is reduced by 75%, the nitrogen oxide emission is reduced by 50%, and the sulfur dioxide emission is reduced by 50%. 66% reduction in volume.

Example 2

Mix limonite-type laterite-nickel ore, quicklime, limestone, and dolomite so that the alkalinity is 1.4, mix vigorously, add water, mix evenly, and granulate. First lay a layer of sintered ore with a thickness of 33mm and a particle size of 10-25mm on the trolley as the base material, and then distribute the sintered mixture evenly on the trolley with a cloth height of 400mm and a particle size of 5-10mm. At the same time, lay a layer of sinter side material with a thickness of 30mm and a particle size of 10-25mm between the sintering mixture and the side plate of the trolley, and run through the circulation of the trolley. The sintered mixture is sequentially dried, preheated, sintered, cooled, and then crushed and screened under the action of hot air at different temperatures.

The blast drying hot air comes from the medium-temperature flue gas in the second cooling stage and the second half of sintering, the temperature is 150°C, and the airflow passes through the material bed from bottom to top.

The hot air for extraction and drying comes from the medium-temperature flue gas and combustion system in the cooling stage and the second half of the sintering stage. The temperature is 400°C and the air flow passes through the material bed from top to bottom. The total time of blast drying and exhaust drying is 25 minutes.

The preheating process is exhaust preheating. The preheating hot air comes from the burner system, the medium-high temperature flue gas in the second half of the sintering and the high-temperature flue gas in the first cold section. The preheating temperature is 1000°C. The time is 10 minutes.

The sintering process is draft sintering, the sintering hot air comes from the combustion system and the high-temperature flue gas in the cooling section, the sintering temperature is 1250°C, and the sintering time is 15 minutes.

In the soaking section, the temperature is 800° C.; the soaking time of the material layer is 4 minutes.

The cooling medium of the primary cooling is natural air, and the air flow direction passes through the material layer from bottom to top, and the cooling time is 15 minutes. The medium of secondary cooling is natural air, and the air flow direction passes through the material layer from bottom to top, and the cooling time is 10min.

The finished sintered ore is obtained, the finished product rate is 82%, and the drum is 70%. Compared with the traditional belt-type draft sintering, the energy consumption of the sintering process of the present invention is reduced by 58%, the carbon dioxide emission is reduced by 78%, the nitrogen oxide emission is reduced by 70%, and the sulfur dioxide emission is reduced. 75% reduction in volume.

Example 3

Mix limonite-type lateritic nickel ore, quicklime, limestone, and dolomite so that the alkalinity is 1.6, mix vigorously, add water to mix evenly, and granulate. First lay a layer of sintered ore with a thickness of 40mm and a particle size of 10-25mm on the trolley as the base material, and then distribute the sintered mixture evenly on the trolley with a cloth height of 500mm and a particle size of 5-10mm. At the same time, lay a layer of sinter side material with a thickness of 40mm and a particle size of 10-25mm between the sintering mixture and the side plate of the trolley, and run through the circulation of the trolley. The sintered mixture is sequentially dried, preheated, sintered, cooled, and then crushed and screened under the action of hot air at different temperatures.

The blast drying hot air comes from the medium-temperature flue gas in the second cooling stage and the second half of sintering, the temperature is 150°C, and the airflow passes through the material bed from bottom to top.

The exhausting and drying hot air comes from the medium-temperature flue gas and the combustion system in the cooling stage and the second half of the sintering stage. The temperature is 500°C and the airflow passes through the material bed from top to bottom.

The preheating process is exhaust preheating. The preheating hot air comes from the burner system, the medium-high temperature flue gas in the second half of the sintering section and the high-temperature flue gas in the first cold section. The preheating temperature is 950°C. The time is 20 minutes.

The sintering process is draft sintering, the sintering hot air comes from the combustion system and the high-temperature flue gas in the cooling section, the sintering temperature is 1350°C, and the sintering time is 15 minutes.

In the soaking section, the temperature is 850° C.; the soaking time of the material layer is 5 minutes.

The cooling medium of the primary cooling is natural air, and the air flow direction passes through the material layer from bottom to top, and the cooling time is 18min. The medium of secondary cooling is natural air, and the air flow direction passes through the material layer from bottom to top, and the cooling time is 18min.

The finished sintered ore is obtained, the finished product rate is 83%, and the drum is 68%. Compared with the traditional belt-type draft sintering, the energy consumption of the sintering process of the present invention is reduced by 60%, the carbon dioxide emission is reduced by 78%, the nitrogen oxide emission is reduced by 77%, and the sulfur dioxide emission is reduced. 79% reduction in volume.

Comparative example 1

Mix limonite-type lateritic nickel ore, quicklime, limestone, and dolomite so that the alkalinity is 0.7, mix vigorously, add water to mix, and granulate. First lay a layer of sintered ore with a thickness of 35mm and a particle size of 10-25mm on the trolley as the base material, and then distribute the sintered mixture evenly on the trolley with a cloth height of 300mm and a particle size of 5-10mm. At the same time, lay a layer of sinter side material with a thickness of 25mm and a particle size of 10-25mm between the sintering mixture and the side plate of the trolley, and run through the circulation of the trolley. The sintered mixture is sequentially dried, preheated, sintered, cooled, and then crushed and screened under the action of hot air at different temperatures.

The blast drying hot air comes from the medium-temperature flue gas in the second cooling stage and the second half of sintering, the temperature is 120°C, and the airflow passes through the material bed from bottom to top.

The hot air for extraction and drying comes from the medium-temperature flue gas and the combustion system in the cooling stage and the second half of the sintering stage. The temperature is 350 ° C. The air flow passes through the material bed from top to bottom. The total time of blast drying and exhaust drying is 20 minutes.

The preheating process is exhaust preheating. The preheating hot air comes from the burner system, the medium-high temperature flue gas in the second half of the sintering and the high-temperature flue gas in the first cold section. The preheating temperature is 900°C. The time is 15 minutes.

The sintering process is draft sintering, the sintering hot air comes from the combustion system and the high-temperature flue gas in the cooling section, the sintering temperature is 1300°C, and the sintering time is 12 minutes.

In the soaking section, the temperature is 750° C.; the soaking time of the material layer is 3 minutes.

The cooling medium of the primary cooling is natural air, and the air flow direction passes through the material layer from bottom to top, and the cooling time is 12 minutes. The medium of secondary cooling is natural air, and the air flow direction passes through the material layer from bottom to top, and the cooling time is 5min.

The finished sintered ore is obtained, the finished product rate is 45%, and the drum is 60%. Compared with the traditional belt-type draft sintering, the energy consumption of the sintering process of the present invention is reduced by 40%, the emission of carbon dioxide is reduced by 55%, the emission of nitrogen oxides is reduced by 40%, and the emission of sulfur dioxide is reduced by 40%. 46% reduction in volume.

Comparative example 2

Mix limonite-type lateritic nickel ore, quicklime, limestone, and dolomite so that the alkalinity is 1.5, add water, mix well, and granulate. First lay a layer of sintered ore with a thickness of 35mm and a particle size of 10-25mm on the trolley as the base material, and then distribute the sintered mixture evenly on the trolley with a cloth height of 300mm and a particle size of 5-10mm. At the same time, lay a layer of sinter side material with a thickness of 25mm and a particle size of 10-25mm between the sintering mixture and the side plate of the trolley, and run through the circulation of the trolley. The sintered mixture is sequentially dried, preheated, sintered, cooled, and then crushed and screened under the action of hot air at different temperatures.

The blast drying hot air comes from the medium-temperature flue gas in the second cooling stage and the second half of sintering, the temperature is 120°C, and the airflow passes through the material bed from bottom to top.

The hot air for extraction and drying comes from the medium-temperature flue gas and the combustion system in the cooling stage and the second half of the sintering stage. The temperature is 350 ° C. The air flow passes through the material bed from top to bottom. The total time of blast drying and exhaust drying is 20 minutes.

The preheating process is exhaust preheating. The preheating hot air comes from the burner system, the medium-high temperature flue gas in the second half of the sintering and the high-temperature flue gas in the first cold section. The preheating temperature is 900°C. The time is 15 minutes.

The sintering process is draft sintering, the sintering hot air comes from the combustion system and the high-temperature flue gas in the cooling section, the sintering temperature is 1300°C, and the sintering time is 12 minutes.

In the soaking section, the temperature is 750° C.; the soaking time of the material layer is 3 minutes.

The cooling medium of the primary cooling is natural air, and the air flow direction passes through the material layer from bottom to top, and the cooling time is 12 minutes. The medium of secondary cooling is natural air, and the air flow direction passes through the material layer from bottom to top, and the cooling time is 5min.

The finished sintered ore is obtained, the finished product rate is 65%, and the drum is 62%. Compared with the traditional belt draft sintering, the energy consumption of the sintering process of the present invention is reduced by 45%, the carbon dioxide emission is reduced by 55%, the nitrogen oxide emission is reduced by 45%, and the sulfur dioxide emission is reduced by 45%. Volume reduced by 40%.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form; all those skilled in the art can smoothly implement the present invention as shown in the accompanying drawings and the above; Without departing from the scope of the technical solution of the present invention, some changes, modifications and equivalent changes made by those skilled in the art using the technical content disclosed above are all equivalent embodiments of the present invention; at the same time, all Any equivalent changes, modifications and evolutions made to the above embodiments according to the substantive technology of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims (7)

1. A sintering method of limonite type laterite-nickel ore adopts a sintering system of limonite type laterite-nickel ore to sinter, and is characterized by comprising the following steps: the preheating section (11) and the sintering section (12) are heated by using gas fuel as fuel of a burner device, wherein:

the sintering system of limonite type laterite-nickel ore comprises: the material distributing device comprises a material distributing device (1), a powerful mixing device (2), a granulating device (3), a screening device (4) and a material distributing device (5), wherein the material distributing device (5) is a multi-roller material distributing machine; a belt sintering device for sintering the cloth; the crushing device (6), the vibrating screen (7) and the temporary storage finished product bin (8) are used for sequentially crushing and screening the sintered materials and collecting finished products; the strand sintering apparatus includes: the air-blast drying section (9), the air-draft drying section (10), the preheating section (11), the sintering section (12), the soaking section (13), the first cooling section (14) and the second cooling section (15) which are sequentially communicated are arranged, the first cooling section (14) is provided with a first air inlet positioned at the lower part of the first cooling section and a first hot air outlet positioned at the upper part of the first cooling section, the second cooling section (15) is provided with a second air inlet positioned at the lower part of the second cooling section and a second hot air outlet positioned at the upper part of the second cooling section, the soaking section (13) is provided with a third hot air outlet positioned at the lower part of the soaking section, the sintering section (12) is provided with a fourth hot air inlet positioned at the upper part of the sintering section and a fourth hot air outlet positioned at the lower part of the sintering section, the preheating section (11) is provided with a fifth hot air inlet positioned at the upper part of the preheating section and a fifth hot air outlet positioned at the lower part of the preheating section, the air draft drying section (10) is provided with a sixth hot air inlet positioned at the upper part of the air draft drying section and a sixth hot air outlet positioned at the lower part of the air draft drying section, the blast drying section (9) is provided with a seventh lower hot air inlet positioned at the lower part of the blast drying section and a seventh hot air outlet positioned at the upper part of the blast drying section, the first hot air outlet is communicated with the fourth hot air inlet, the second hot air outlet is communicated with the seventh lower hot air inlet through a blast dryer, the third hot air outlet and the fourth hot air outlet are respectively communicated with a backheating fan, and the backheating fan is respectively communicated with the fifth hot air inlet and the sixth hot air inlet; and a burner device for heating the preheating section (11) and the sintering section (12);

in the forced air drying section (9), the temperature of hot air entering from the seventh lower hot air inlet is 100-300 ℃, and air flow penetrates through the material layer from bottom to top; the retention time of the material layer is 10-30min;

in the air draft drying section (10), the temperature of hot air entering from the sixth hot air inlet is 300-600 ℃, and air flow passes through the material layer from top to bottom; the retention time of the material layer is 10-30min;

the hot air entering the fifth hot air inlet and the burner device heat the interior of the preheating section (11) to a preheating temperature of 900-1150 ℃; preheating the material layer for 10-30min;

the hot air entering from the fourth hot air inlet and the burner device heat the interior of the sintering section (12) to 1250-1350 ℃; the sintering time of the material layer is 12-30 min;

in the soaking section (13), the temperature is 750-850 ℃; the soaking time of the material layer is 3-5 min;

in the first cooling section (14), a cooling medium is natural air and enters from a first air inlet, and the airflow direction penetrates through the material layer from bottom to top; the cooling time of the material layer is 12-20 min;

in the second cooling section (15), a cooling medium is natural air, and the cooling medium passes through the material layer from bottom to top through a second air inlet in the airflow direction; the cooling time of the material layer is 4-15 min.

2. The sintering method of limonite type lateritic nickel ore according to claim 1, characterized in that: the limonite type laterite-nickel ore, quick lime, limestone and dolomite are proportioned by the proportioning device (1), and the obtained proportioned material meets the alkalinity of 0.8-1.7.

3. The sintering method of limonite type lateritic nickel ores according to claim 1, characterised in that:

the screened materials with the particle size below 5mm are conveyed back to the intensive mixing device (2) through a conveying mechanism arranged below the screening device (4);

and materials with the grain diameter below 5mm are conveyed back to the powerful mixing device (2) through a conveying mechanism arranged below a sieve plate of the multi-roller distributing machine.

4. The sintering method of limonite type lateritic nickel ores according to claim 1, characterised in that: firstly paving a layer of sintering ore with the thickness of 30-80 mm and the granularity of 10-25mm on a trolley of a belt sintering device as a bedding material, then uniformly distributing the sintering mixture on the trolley through a multi-roller distributing machine, wherein the distributing height is 200-500 mm and the granularity is 5-25 mm, paving a layer of sintering ore leftover with the thickness of 20-60 mm and the granularity of 10-25mm between the sintering mixture and a trolley side plate, and then sintering.

5. The sintering method of limonite type lateritic nickel ores according to claim 1, characterised in that:

a conveying mechanism is arranged below the screening device (4) and used for conveying screened materials to the intensive mixing device (2);

and a conveying mechanism is arranged below the multi-roller distributing machine and used for conveying materials with insufficient particle size to the intensive mixing device (2).

6. The sintering method of limonite type lateritic nickel ores according to claim 1, characterised in that: the system further comprises an electric dust collector (16), an exhaust fan (17) and a smoke exhaust pipeline (18) which are sequentially communicated with one another, the sixth hot air outlet and/or the fifth hot air outlet are communicated with the electric dust collector (16) and/or a dust exhaust port is arranged in front of the blast drying section (9), and the dust exhaust port is communicated with the electric dust collector (16).

7. The sintering method of limonite type lateritic nickel ores according to claim 1, characterised in that: the system further comprises a bottom material paving device (19) for paving the bottom material of the belt type sintering device, and the vibrating screen (7) is provided with a conveying mechanism for conveying undersize to the bottom material paving device (19).

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