CN215295787U

CN215295787U - Lump ore pretreatment system based on shaft tube type rotary kiln

Info

Publication number: CN215295787U
Application number: CN202120674424.1U
Authority: CN
Inventors: 倪桂虎; 廖继勇; 赵强
Original assignee: Zhongye Changtian International Engineering Co Ltd
Current assignee: Zhongye Changtian International Engineering Co Ltd
Priority date: 2021-04-02
Filing date: 2021-04-02
Publication date: 2021-12-24
Anticipated expiration: 2031-04-02

Abstract

The utility model provides a lump ore deposit pretreatment systems based on axle tubular rotary kiln, this system include rotary kiln, the dry screening plant of axle tubular. The shaft tube type drying and screening device is arranged in the rotary kiln. Conveying the lump ore to be treated to a rotary kiln, and introducing a heat medium into the rotary kiln. Drying and screening the lump ore to be treated in a rotary kiln at the same time to obtain dry large-particle lump ore. The utility model provides a pretreatment system which directly adopts a rotary kiln to dry, which solves the problem of large water content in natural lump ore; drying and screening the lump ore in a shaft tube type rotary kiln to remove moisture of the lump ore, wherein a heat source required for drying is preferably hot waste gas from a steel mill. The utility model provides a pretreatment systems is simple and easy, practical, reliable, does benefit to the engineering and popularizes and applies.

Description

Lump ore pretreatment system based on shaft tube type rotary kiln

Technical Field

The utility model provides a pretreatment systems of lump ore, concretely relates to lump ore pretreatment systems based on axle tubular rotary kiln belongs to steel smelting technical field.

Background

The consumption of steel as an irreplaceable structural and functional material in the industrialization process occupies more than 95 percent of the total consumption of metal in a long time. The raw pig iron materials required by the iron and steel industry are mainly provided by blast furnace smelting, and the improvement of the blast furnace smelting technology and the reduction of the cost have profound significance for promoting the development of iron and steel enterprises. The basic link of blast furnace intensified smelting is fine material operation, natural lump ore is used as one of the main components of the charging material, and the addition amount can reach 20 percent at most. Because the moisture content of the lump ore is high, after the high-moisture lump ore enters the furnace, the moisture drying needs to consume energy, the drying process needs a certain time, and the coke ratio of the blast furnace is improved, so that the air permeability of a blast furnace charge layer is influenced, the smelting cost of the blast furnace is increased, and the furnace condition is influenced to be stable. Therefore, the reduction of the moisture content of the lump ore has important significance for reducing the iron-making cost and enhancing the stability of the furnace condition. At present, lump ore drying systems have the difficult problems of high construction cost, low drying efficiency, high energy consumption and the like.

Common furnace charging materials for blast furnaces include sintered ores, pellets and natural lump ores. The reasonable blast furnace charging material structure is that the optimum matching proportion of different types of iron-containing ores is found out by adjusting the proportion of sintered ores, pellets and natural lump ores in the iron ores fed into the furnace, so that various economic and technical indexes of blast furnace smelting under the charging material structure are relatively ideal, and the consumption cost of unit pig iron smelting is relatively lowest. Research shows that the cost expenditure of iron ore and other raw material links accounts for about 60% of the total pig iron cost, the market price of lump ore is basically equal to that of fine ore, the cost price is far lower than that of sinter and pellet ore, and the improvement of the charging proportion of the lump ore is an effective measure for reducing the raw material cost of a blast furnace. At present, the charging proportion of lump ore is generally 5-15%, and the proportion is low. The reason for this is that the lump ore has a high water content of generally 8-15%, and the water content of the lump ore in rainy season in individual harbor steel mills even exceeds 20%. The problem of high moisture content exists when the lump ore enters the furnace, energy is consumed for moisture drying after the high moisture lump ore enters the furnace, a certain time is needed in the drying process, and the coke ratio of the blast furnace is improved.

Therefore, the reduction of the moisture content in the lump ore has important significance for reducing the iron-making cost and enhancing the stability of the furnace condition. At present, lump ore drying systems have the difficult problems of high construction cost, low drying efficiency, high energy consumption and the like.

SUMMERY OF THE UTILITY MODEL

The water content of the iron ore lump ore is generally 8-15%, and the water content of the lump ore in rainy season of individual port steel mills even exceeds 20%. After the high-moisture lump ore is fed into the furnace, energy is consumed for moisture drying, a certain time is needed in the drying process, and the coke ratio of the blast furnace is improved. Research shows that drying treatment of lump ore in a rotary kiln by using a heat medium is feasible, so that moisture of charged lump ore can be effectively reduced, energy consumption required by drying can be greatly reduced, and the charging proportion of the dried lump ore can be improved to a certain extent, thereby reducing the smelting cost of a blast furnace.

In addition, research shows that lump ore exists in a stacked state in the rotary kiln, particularly fine materials exist, so that the air permeability of the whole materials in the rotary kiln is deviated, hot air flow cannot smoothly penetrate through a material body, the drying effect is poor, and the temperature of the feed end of the rotary kiln is lower than the dew point temperature of moisture, so that water vapor is easily condensed, and the dust removal system is damaged. Meanwhile, part of fine materials are easy to be bonded on the wall surface of the rotary kiln under the action of local high temperature, and the service life of the rotary kiln is shortened.

The utility model discloses a stoving process utilizes the abundant characteristics of the hot waste gas resource of steel flow, introduces the rotary kiln with hot waste gas nearby, directly carries out the drying to the material in the kiln, reduces the moisture of lump ore deposit.

The utility model discloses a to the shortcoming that the lump ore deposit was dried in the rotary kiln, plan to adopt axle tubular rotary kiln drying device to dry the lump ore deposit, in the rotary kiln, a plurality of axle tubular drying and screening devices evenly arrange, and each axle tubular drying and screening device includes predrying section and drying sieve segmentation. Lump ore passes through from the inner chamber of shaft tubular drying and screening device, is provided with the sieve mesh on the dry sieve segmentation's of shaft tubular drying and screening device pipe wall, can realize separating the fine particle material that will mix with in the lump ore to the intermediate layer cavity (thin material passageway) that is located the shaft tubular drying and screening device outside via the sieve mesh from this, and then realize the purpose of the thick of lump ore, thin material separation. Airflow enters the kiln from the discharge end of the rotary kiln, contacts with lump ore for heat exchange, reversely passes through the shaft tube type drying and screening device and then is discharged from the feed end of the rotary kiln. Or the airflow enters the kiln from the discharge end of the rotary kiln, directly contacts with the lump ore for heat exchange in the drying screen section, enters the interlayer cavity, and the hot airflow entering the interlayer cavity indirectly exchanges heat with the lump ore in the pre-drying section and is discharged to the dust removal system through the heat medium outlet on the side wall of the rotary kiln. The hot air flow is fully distributed in the whole rotary kiln, the heat exchange rate of the hot air flow and lump ore is improved, the air permeability in the rotary kiln is improved, and the drying effect is enhanced. The utility model discloses a system simple and easy, practical, reliable, the abundant characteristics of make full use of steel mill hot waste gas resource effectively reduce lump ore preliminary treatment cost, solve the lump ore and go into a stove and add the difficult problem that the rate is low, improved the lump ore of blast furnace and gone into stove proportion and gas permeability level, effectively reduced blast furnace manufacturing cost, improved the blast furnace level of going forward.

Furthermore, the utility model also discloses a pretreatment methods that is used for the screening and dries the lump ore. The utility model discloses to the many and big difficult problem of moisture of powder that natural lump ore exists, provided and utilized the hot waste gas of steel process directly to carry out screening and dry method to the lump ore in the rotary kiln. Firstly, hot waste gas is introduced to raise the temperature of the rotary kiln, and the temperature level is stabilized for a certain time. Then, the lump ore material is added from the lump ore feed inlet, passes through from a plurality of axle tubular drying and screening device's of evenly arranging inner chamber, and the dry screening device's of axle tubular material of flowing through material is dry on one side in transportation process, and the intermediate layer cavity is also constantly fallen into from the sieve mesh to fine material simultaneously, realizes the separation of thick, fine material to make the clearance between the lump ore more unobstructed, and then make the heat transfer effect of lump ore and hot-medium obtain very big promotion. Lump ore continuously flows through the inner cavity of the shaft tube type drying and screening device, airflow is continuously introduced into the rotary kiln, the lump ore is in a flowing state and carries out gas-solid exchange with hot waste gas, and hot airflow is distributed over the whole rotary kiln, so that the moisture content of the lump ore is reduced. And the airflow is discharged to a dust removal system from a feeding end of the rotary kiln or a heat medium outlet on the side wall of the rotary kiln, and the dried lump ore is conveyed to a blast furnace feeding system from a discharging end of the rotary kiln. And a moisture detector is arranged at the lump ore feeding port and/or the lump ore discharging port of the rotary kiln, and the quantity of the heat medium which needs to be conveyed into the rotary kiln in unit time is reasonably adjusted (controlled by adjusting the flow speed) according to moisture detection data. The utility model discloses can increase substantially the contact efficiency of hot gas flow and lump ore for gas permeability obtains improving in the kiln, and the stoving effect is strengthened. The utility model discloses a popularization has good economic benefits and environmental benefit, is expected to open up a more stable efficient way for lump ore pretreatment process in the development of china.

According to the utility model provides a first embodiment provides a lump ore pretreatment systems of axle tubular rotary kiln.

A lump ore pretreatment system based on an axial tube type rotary kiln comprises the rotary kiln and an axial tube type drying and screening device. The rotary kiln is provided with a lump ore feed inlet and a lump ore discharge outlet. The shaft tube type drying and screening device is arranged in the rotary kiln. According to the trend of lump ore, the shaft tube type drying and screening device is divided into a pre-drying section and a drying and screening section. The pre-drying section is communicated with a lump ore feeding hole of the rotary kiln, and the drying screen section is communicated with a lump ore discharging hole of the rotary kiln. The rotary kiln is also provided with a heat medium inlet and a heat medium outlet. The heat medium inlet is connected with a heat medium conveying pipeline.

Preferably, the shaft tube type drying and screening device is of a tube cavity type structure with two open ends. Wherein, the pipe wall of the drying screen section of the shaft tube type drying and screening device is provided with a screen hole. An interlayer chamber is arranged between the outer wall of the shaft tube type drying and screening device and the inner wall of the rotary kiln. The drying screen section is communicated with the interlayer chamber through the screen holes. And a fine material discharge port is also arranged on the interlayer chamber. The fine material discharge port is arranged on the side wall of the rotary kiln and is positioned at a position close to the lump ore discharge port. Namely, the fine material discharge port is arranged on the side wall of the rotary kiln, and the fine material discharge port is communicated with the interlayer chamber.

Preferably, the screen openings are distributed uniformly over the wall of the drying screen section. The aperture of the sieve pore is 5-20 mm, preferably 6-15 mm, and more preferably 7-10 mm.

Preferably, a material distribution chamber is arranged at the feeding end of the rotary kiln, and a material collection chamber is arranged at the discharging end of the rotary kiln. The shaft tube type drying and screening device is positioned between the material distribution chamber and the material collection chamber. The lump ore feed inlet is arranged on the material distribution chamber, and the lump ore discharge outlet is arranged on the material collection chamber. Wherein: lump ore enters the material distribution chamber from the lump ore feed inlet, then passes through the shaft tube type drying and screening device and then enters the material collection chamber. Meanwhile, powder attached to the lump ore enters the interlayer chamber through the screen holes on the pipe wall of the drying screen section and is then discharged from the fine material discharge port. The heat medium inlet is arranged on the material collecting chamber. The heat medium outlet is arranged on the material distribution chamber. And the heat medium enters the rotary kiln from a heat medium inlet on the material collection chamber, directly contacts with lump ore for heat exchange, reversely flows through the shaft tube type drying and screening device and then is discharged from a heat medium outlet on the material distribution chamber.

Preferably, a material distribution chamber is arranged at the feeding end of the rotary kiln, and a material collection chamber is arranged at the discharging end of the rotary kiln. The shaft tube type drying and screening device is positioned between the material distribution chamber and the material collection chamber. The lump ore feed inlet is arranged on the material distribution chamber, and the lump ore discharge outlet is arranged on the material collection chamber. Wherein: lump ore enters the material distribution chamber from the lump ore feed inlet, then passes through the shaft tube type drying and screening device and then enters the material collection chamber. Meanwhile, powder attached to the lump ore enters the interlayer chamber through the screen holes on the pipe wall of the drying screen section and is then discharged from the fine material discharge port. The material collecting chamber is provided with a heat medium inlet. And the side walls of the material distribution chamber and the rotary kiln are provided with heat medium outlets. And the heat medium outlet on the side wall of the rotary kiln is positioned close to the pre-drying section.

The heat media are respectively: the heat medium enters the rotary kiln from a heat medium inlet on the material collecting chamber, directly contacts with lump ore for heat exchange, reversely flows through the shaft tube type drying and screening device, and is discharged from a heat medium outlet on the material distributing chamber.

Secondly, the hot medium enters the rotary kiln from a hot medium inlet on the material collecting chamber, directly contacts with lump ore for heat exchange, reversely flows through the shaft tube type drying and screening device, enters the interlayer chamber through sieve holes on the tube wall of the drying and screening section, and is discharged from a hot medium outlet on the side wall of the rotary kiln.

Preferably, the system comprises a plurality of said shaft tube type drying and screening devices. A plurality of shaft tube type drying and screening devices are arranged inside the rotary kiln. The feed inlets of all the shaft tube type drying and screening devices are communicated with the material distribution chamber. The discharge ports of all the shaft tube type drying and screening devices are communicated with the material collecting chamber.

Preferably, the number of the shaft tube type drying and screening devices is 1-20, preferably 2-15, more preferably 3-10.

Preferably, a first moisture detection device, a first material flow detection device and a first material temperature detection device are arranged at a lump ore feeding port on the rotary kiln.

Preferably, a second moisture detection device is arranged at the lump ore discharge outlet of the rotary kiln.

Preferably, the rotary kiln is arranged obliquely, and the horizontal position of the feeding end of the rotary kiln is higher than the horizontal position of the discharging end of the rotary kiln. Preferably, the inclination angle of the rotary kiln is 0-60 degrees, preferably 2-45 degrees, and more preferably 5-30 degrees.

Preferably, the system also comprises a blast furnace, and the lump ore discharge hole is connected with the feed inlet of the blast furnace through an ore material conveying device.

Preferably, the system further comprises a dust removal system, and the heat medium outlet is communicated to the dust removal system through a heat medium discharge pipeline.

Preferably, the system further comprises a fan provided on the heat medium discharge pipe.

According to the second embodiment provided by the utility model, a lump ore pretreatment method based on the shaft tube type rotary kiln is provided.

The utility model relates to a lump ore pretreatment method based on axle tubular rotary kiln or adopt like the utility model discloses a first embodiment the system carries out the method of lump ore pretreatment, and this method includes following step:

1) conveying the lump ore to be treated to a rotary kiln, and introducing a heat medium into the rotary kiln.

2) Drying and screening the lump ore to be treated in a rotary kiln through a shaft tube type drying and screening device at the same time to obtain dry large-particle lump ore.

Preferably, the method further comprises the steps of:

a) before the lump ore to be treated is conveyed to the rotary kiln, the rotary kiln is firstly dried by adopting a heat medium, and the heat medium preheats the rotary kiln.

3) And after the heat medium exchanges heat with lump ore in the rotary kiln, the heat medium is discharged from the rotary kiln, and the discharged heat medium is conveyed to a dust removal system.

4) And conveying the dried large-particle lump ore obtained after drying and screening treatment to a blast furnace.

Preferably, a first moisture detection device, a first material flow rate detection device and a first material temperature detection device are arranged at the lump ore feed inlet of the rotary kiln. The first moisture detection device detects the moisture content in the lump ore entering the rotary kiln and marks as W₀% of the amount of the compound (b). The first material flow detection device detects the lump ore amount entering the rotary kiln in unit time and marks the lump ore amount as M₀，m³. The first material temperature detection device detects the lump ore temperature entering the rotary kiln and records the temperature as T₀At deg.C. Setting the upper limit of the moisture content of the lump ore entering the blast furnace as W according to the condition requirements of the blast furnace_max% of the amount of the compound (b). Calculating the flow rate V, m of the heat medium delivered to the rotary kiln per unit time³：

Figure 745754DEST_PATH_GDA0003314956110000051

Wherein: c_{Article (A)}Is the specific heat capacity of the lump ore, C_MediumIs the specific heat capacity of the thermal medium. Rho_{Article (A)}Is the bulk density of the lump ore,ρ_mediumIs the density of the thermal medium. T is the temperature at which the heat medium is fed into the rotary kiln.

In unit time, conveying a heat medium with the flow not less than V to the rotary kiln, and drying the lump ore in the rotary kiln by the heat medium to ensure that the moisture content of the lump ore before entering the blast furnace is lower than W_max。

Preferably, a first moisture detecting device is provided at the lump ore feed port of the rotary kiln, and the initial air velocity of the heat medium to be conveyed to the rotary kiln is set to S₀M/s. The first moisture detection device detects the moisture content in the lump ore entering the rotary kiln and marks as W₁% of the amount of the compound (b). Setting the upper limit of the moisture content of the lump ore entering the blast furnace as W according to the condition requirements of the blast furnace_max% of the amount of the compound (b). Judgment of W₁And W_maxAdjusting the real-time gas velocity S of the heat medium delivered to the rotary kiln₁M/s. The method comprises the following steps:

when W is₁≤W_maxWhen the heat medium is not supplied to the rotary kiln, the supply of the heat medium into the rotary kiln is stopped.

When W is₁When the content is more than or equal to 10 percent, S₁＝[1+k₁·(W₁-10％)]×S₀。

When 10% is more than W₁When greater than 6%, S₁＝S₀。

When W is_max＜W₁When the content is less than or equal to 6 percent, S₁＝[1-k₂·(6％-W₁)]×S₀。

Wherein k is₁、k₂For the coefficient of flow regulation, k₁Has a value range of 3-5, k₂The value range of (A) is 1 to 3. W_maxLess than or equal to 4 percent. Real-time detection of W₁Adjusting the real-time air flow velocity of the heat medium delivered to the rotary kiln to be S₁Drying the lump ore in a rotary kiln by a heat medium to ensure that the moisture content of the lump ore before entering the blast furnace is lower than W_max。

Preferably, a second moisture detecting device is provided at the lump ore discharge port of the rotary kiln, and the initial air velocity of the heat medium to be conveyed to the rotary kiln is set to S₀M/s. Second moisture detection device detects rotary kiln exhaust pieceWater content in the ore, denoted W₂. Setting the upper limit of the moisture content of the lump ore entering the blast furnace as W according to the condition requirements of the blast furnace_max% of the amount of the compound (b). Judgment of W₂And W_maxAdjusting the real-time gas velocity S of the heat medium delivered to the rotary kiln₂M/s. The method comprises the following steps:

when W is₂≥W_maxWhen S is present₂＝[1+k₃·(W₂-W_max)]×S₀。

When the pressure is 0.5W_max＜W₂＜W_maxWhen S is present₂＝S₀。

When W is₂≤0.5W_maxWhen S is present₂＝[1-k₄·(0.5W_max-W₂)]×S₀。

Wherein k is₃、k₄For the coefficient of flow regulation, k₃Has a value range of 1-3, k₄The value range of (A) is 0.5-2. W_maxIs less than 6 percent. Real-time detection of W₂Adjusting the real-time air flow velocity of the heat medium delivered to the rotary kiln to be S₂Drying the lump ore in a rotary kiln by a heat medium to ensure that the moisture content of the lump ore before entering the blast furnace is lower than W_max。

Preferably, the heat medium is a heat source generated in the steel process. Preferably, the heat medium is a heat source released by combustion of sintering circular cooler hot exhaust gas, blast furnace hot blast stove exhaust gas, coke oven gas/blast furnace gas/converter gas, and is preferably sintering circular cooler hot exhaust gas or blast furnace hot blast stove exhaust gas.

Preferably, the temperature of the heat medium entering the rotary kiln is greater than 100 ℃, preferably greater than 150 ℃.

Preferably, the air flow speed of the heat medium entering the rotary kiln is 0.01-3 m/s, preferably 0.03-2 m/s, and more preferably 0.05-1 m/s.

Preferably, the retention time of the lump ore in the rotary kiln is 0.5-24 h, preferably 1-12 h, and more preferably 2-8 h.

And/or

Preferably, the large-particle lump ore has a particle size of more than 5mm, preferably more than 6mm, and more preferably more than 8 mm. The utility model provides a system for carry out lump ore preliminary treatment and preliminary treatment at rotary kiln. The utility model provides a pretreatment method for directly adopting a rotary kiln to dry and screen aiming at the difficult problem of large moisture in natural lump ore; the lump ore is pretreated by drying and screening in a rotary kiln, coarse materials and fine materials are screened while water in the lump ore is removed (after the lump ore is screened according to the granularity or the grain diameter, the lump ore (coarse materials on a screen) after the grain diameter screening and the water reduction is conveyed to a blast furnace for a smelting process, while fine materials under the screen can be conveyed to a sintering batching system, and materials under the screen enter a sintering process). The heat source required for drying preferably comes from steel mill hot exhaust gases (e.g. hot exhaust gases from blast furnaces). The utility model provides a pretreatment methods is simple and easy, practical, reliable, does benefit to the engineering and popularizes and applies, compares with traditional drum drying process technology, the utility model discloses a ripe rotary kiln carries out the pretreatment technology of drying and screening, because the rotary kiln is a confined environment relatively, the moisture desorption of lump ore is efficient, has solved the lump ore and has gone into stove (blast furnace) difficult problem, has improved the stove proportion and the gas permeability level of going into of blast furnace lump ore, has effectively reduced blast furnace manufacturing cost, has improved the blast furnace level of going forward. The popularization of the utility model has good economic, social and environmental benefits, and is expected to open up a more stable and efficient way for the development of the lump ore pretreatment process in China.

In the present invention, the heat medium may be hot exhaust gas with a high temperature or hot air after heat treatment. Generally, the temperature of the thermal medium is 100 ℃ or higher.

In the utility model, aiming at the problems of large moisture content in lump ore and low addition amount of raw materials of the blast furnace, the lump ore is dried and pretreated by adopting the rotary kiln, and a heat medium is conveyed to the rotary kiln; in the rotary kiln, the heat medium dries and sieves the lump ore, evaporates and takes away the water in the lump ore, and the heat medium after heat exchange is discharged out of the rotary kiln together to achieve the purpose of drying the lump ore, and simultaneously, the step of sieving and separating coarse and fine materials of the lump ore is also realized in the drying process.

Preferably, before the lump ore to be processed is conveyed to the rotary kiln, the rotary kiln is preheated by the heat medium, so that the internal temperature of the rotary kiln is increased, moisture condensation is avoided when the lump ore with high moisture content enters the rotary kiln, and the drying effect of the lump ore in the rotary kiln is further improved.

Preferably, after the heat medium exchanges heat with the lump ore in the rotary kiln, the heat medium takes away moisture in the lump ore, meanwhile, the heat medium can remove dust on the surface of the lump ore, the content of the dust in the rotary kiln is reduced, and the air permeability of the heat medium in the rotary kiln is increased, so that the drying efficiency is improved. Preferably, the heat medium discharged from the rotary kiln is subjected to dust removal treatment by a dust removal system, so that the pollution of the discharged heat medium to the environment is reduced. Meanwhile, the dust particles collected by the dust removal system can be used as sintering raw materials, and resource recycling is realized.

Preferably, lump ore exists in a stacked state in the rotary kiln, especially the existence of fine-grained materials, which causes the air permeability of the whole material of the rotary kiln to be deviated, and the drying effect is influenced. Part of fine materials are easy to be adhered to the wall surface of the rotary kiln under the action of local high temperature, and the service life of the rotary kiln is shortened. The utility model discloses when carrying out the drying with pending lump ore deposit to the rotary kiln, the lump ore deposit of handling also carries out screening process, and the lump ore deposit is down in-process in the rotary kiln, and tiny material lasts and falls into to the intermediate layer cavity from the sieve mesh to improved the clearance between the lump ore deposit in the coarse fodder passageway (among the dry screening device of axle tube formula), guaranteed that coarse fodder passageway and material collect the gas permeability of room, improved the drying effect of hot medium to the lump ore deposit.

The utility model discloses in, the dry screening plant of axle tubular is including predrying section and dry sieve segmentation. Wherein the drying screen section is provided with screen holes. After the lump ore enters the shaft tube type drying and screening device, pre-drying is firstly carried out in the pre-drying section to remove a part of moisture, and then the lump ore enters the drying and screening section to be further dried and screened. Generally, due to the existence of fine materials, the air permeability of the whole materials in the rotary kiln is deviated, and hot air flow cannot smoothly penetrate through the materials, so that the drying effect is poor. Meanwhile, part of fine materials are easy to be bonded on the wall surface of the rotary kiln under the action of local high temperature, and the service life of the rotary kiln is shortened. Or the fine material is easy to adhere to the large-particle lump ore and is not beneficial to separation. In the pre-drying section, the temperature of the heat medium is relatively low, so that the fine-grained materials can not be adhered to the wall surface of the rotary kiln or the surface of large-grained lump ores in the process of drying the materials. Meanwhile, partial moisture of the materials subjected to pre-drying is removed, the follow-up drying difficulty is reduced, the drying effect is improved, fine materials are more easily separated from large-particle lump ores after the materials are subjected to pre-drying, namely the screening efficiency of the materials subjected to drying is higher, and the screening effect is greatly improved. Furthermore, through the pre-drying process, the surface pore structure of the lump ore can be improved, the water vaporization rate is optimized, the diffusion transmission speed of water vapor is accelerated, and the purpose of preventing the lump ore from bursting can be achieved.

The utility model discloses in, the lump ore passes through axle tubular drying screening plant (be equipped with the sieve mesh in the dry screening section) and sieves the back according to granularity or particle diameter, and the oversize material that accords with the particle diameter requirement and accord with the moisture content requirement on the sieve passes through material conveyor and carries to the blast furnace, has guaranteed that the particle diameter and the moisture content that get into the blast furnace raw materials accord with the requirement to guarantee the smelting effect of blast furnace.

The utility model discloses in, set up first moisture detection device, first material flow detection device and first material temperature detection device through the material feed inlet position at the rotary kiln, moisture content in the lump ore that first moisture detection device detected the entering rotary kiln, the lump ore volume that first material flow detection device got into the rotary kiln in the unit interval, and first material temperature detection device detects the lump ore temperature that gets into the rotary kiln. Setting the upper limit of the water content of the lump ore entering the blast furnace as W_max% of the amount of the compound (b). The flow of the heat medium conveyed to the rotary kiln in unit time can be accurately known through calculation, so that the moisture content of the lump ore before entering the blast furnace is lower than W_max，％。

The utility model discloses in, be equipped with first moisture detection device in the lump ore feed inlet department of rotary kiln, set for the initial air velocity who carries the hot medium to the rotary kilnThe first moisture detection device detects the moisture content in the lump ore entering the rotary kiln, and the upper limit of the moisture content of the lump ore entering the blast furnace is set to W_max% of the amount of the compound (b). The detected water content in the lump ore at the feed inlet is compared with the upper limit of the water content of the lump ore entering the blast furnace, and the real-time air flow speed of the heat medium conveyed to the rotary kiln is adjusted, so that the water content of the lump ore before entering the blast furnace is lower than W_max，％。

The utility model discloses in, be equipped with second moisture detection device in the lump ore discharge gate department of rotary kiln, set for the initial air velocity of carrying to the hot medium of rotary kiln, the moisture content in second moisture detection device detection rotary kiln discharge lump ore sets for the moisture content upper limit that gets into the lump ore in the blast furnace to be W_maxComparing the detected water content in the lump ore at the discharge port with the upper limit of the water content of the lump ore entering the blast furnace, and adjusting the real-time air flow speed of the heat medium conveyed to the rotary kiln, thereby ensuring that the water content of the lump ore before entering the blast furnace is lower than W_max，％。

The utility model discloses in, it is feasible to utilize the hot waste gas of steel process to carry out the drying processing to the lump ore in the rotary kiln, not only can reduce effectively and go into stove lump ore moisture, can reduce the required energy consumption of drying moreover by a wide margin, and the lump ore after the drying can improve to a certain extent and go into the stove proportion, reduces the blast furnace and smelts the cost from this.

Further, the problem that lump ore is not uniformly contacted with a heat medium in the rotary kiln is solved, the lump ore exists in a stacked state in the rotary kiln, especially fine-grained materials exist, so that the air permeability of the whole materials in the rotary kiln is deviated, hot air flow cannot smoothly penetrate through a material body, the drying effect is poor, and the temperature of the feed end of the rotary kiln is lower than the dew point temperature of moisture, so that water vapor is easily condensed, and the dust removal system is damaged. The utility model discloses a to the shortcoming that the lump ore deposit exists of drying in the rotary kiln, adopt the rotary kiln that has the dry screening plant of axle tube formula, a plurality of dry screening plant of axle tube formula evenly arrange in the rotary kiln, and the lump ore deposit gets into the material distribution room from the lump ore feed inlet, then gets into the material behind the coarse fodder passageway (including predrying section and drying screen segmentation) that passes the dry screening plant of axle tube formula and collects the room. The heat medium inlet is arranged on the material collecting chamber. The heat medium outlet is arranged on the material distribution chamber. The heat medium enters the rotary kiln from a heat medium inlet on the material collecting chamber, directly contacts with lump ore for heat exchange, reversely passes through the drying screen section and the pre-drying section of the shaft-tube type drying and screening device, enters the material distributing chamber, and is finally discharged from a heat medium outlet on the material distributing chamber. Thereby enhancing heat exchange between the gas and the solid. Airflow enters the kiln from the discharge end of the rotary kiln and is discharged to the dust removal system from the feed end of the rotary kiln, the whole rotary kiln is full of hot airflow, the contact effect of the hot airflow and lump ore is improved, the air permeability in the kiln is improved, and the drying effect is enhanced.

Preferably, the heat medium outlet is arranged on the side wall of the rotary kiln and is positioned close to the pre-drying section. For example, the heat medium outlet is arranged on the side wall of the rotary kiln corresponding to the position of the pre-drying section, and meanwhile, in the length direction of the rotary kiln, the heat medium outlet is positioned at the position, closest to the material distribution chamber, on the pre-drying section, so that the drying time and the drying effect of the lump ore in the pre-drying section can be ensured, and the heat exchange utilization rate of the heat medium is further improved. At this time, because the heat medium outlet is arranged on the side wall of the rotary kiln, in the pre-drying section, lump ore does not directly contact with the heat medium for heat exchange, but indirectly exchanges heat through the heat transfer of the side wall of the shaft tube type drying and screening device. In the heat exchange and drying process of the lump ore in the pre-drying section, the heat medium in the interlayer cavity is subjected to one-time direct contact heat exchange with the lump ore in the drying and screening section, so that the temperature of the heat medium in the interlayer cavity is relatively low at the moment, fine-particle materials cannot be adhered to the wall surface of the rotary kiln or the surface of large-particle lump ore in the process of indirectly drying the materials, and the pre-drying process of the materials is also favorable for subsequent screening and further drying.

Further, a heat medium outlet is provided on the side wall of the rotary kiln. Hot medium can pass through the sieve mesh at exhaust in-process, and the air current passes from the sieve mesh, is favorable to bringing the powder attached to on the lump ore into the outer intermediate layer cavity of sieve mesh, and then strengthens the utility model discloses the device is to the screening effect of lump ore, and the gas permeability of whole rotary kiln is greatly improved, promotes screening and stoving effect from this.

The utility model discloses in, be provided with the dry screening plant of axle tubular in the rotary kiln, the dry screening plant of axle tubular includes predrying section and dry sieve segmentation. The pre-drying section and the drying screening section are connected in series and communicated. The pre-drying section is communicated with the material distribution chamber or the lump ore feeding port, and the drying screen section is communicated with the material collection chamber or the lump ore discharging port. And screen holes are formed in the pipe wall of the drying screen section. An interlayer chamber is arranged between the outer wall of the shaft tube type drying and screening device and the inner wall of the rotary kiln. The drying screen section is communicated with the interlayer chamber through the screen holes. And a fine material discharge port is arranged on the interlayer cavity. And the fine material discharge port is positioned on the side wall of the rotary kiln close to the lump ore discharge port. The pre-drying section and the drying screen section arranged in the shaft tube type drying and screening device are divided into a coarse material channel, and the interlayer cavity is a fine material channel. The interlayer chambers are arranged outside all the shaft tube type drying and screening devices in a surrounding and coating mode, and screen holes communicated with the interlayer chambers are arranged on the tube walls of the drying and screening sections. Lump ore enters a material distribution chamber from a lump ore feed inlet, then passes through a pre-drying section (pre-drying to remove a certain amount of moisture) and a drying and screening section (further drying to the upper limit of moisture content meeting the requirement of a blast furnace, and simultaneously carrying out screening treatment to separate out fine materials) and then enters a material collection chamber. In the process, the fine materials attached to the large-particle lump ores fall into the interlayer chamber through the sieve pores, so that the aim of separating the coarse materials from the fine materials is fulfilled while drying the lump ores. The utility model relates to a take dry screening plant of axle tubular of sieve mesh can realize the drying and the screening of lump ore deposit through one process. Need not additionally to set up lump ore screening plant and sieve the lump ore, reduced manufacturing cost, also very big improvement production efficiency simultaneously. It should be noted that if an independent screening device is additionally arranged, new fine materials are inevitably generated due to abrasion among lump ores in the process of conveying the large-particle lump ores obtained after screening to the drying device, and further the drying effect of the lump ores and the subsequent blast furnace smelting effect are influenced.

The utility model discloses in, be provided with the fan on heat medium discharge pipe, this fan can adjust the air velocity of heat medium input. The heat medium enters the material collecting chamber from the heat medium inlet and then enters the drying and screening chamber to dry the lump ore. And the dried heat medium enters the material distribution chamber, and is finally conveyed to a dust removal system from a heat medium outlet through a heat medium discharge pipeline under the action of a fan for dust removal and then is discharged.

Adopt the technical scheme provided by the utility model, can increase the interpolation proportion of lump ore in the blast furnace raw materials, through the experiment, adopt the utility model discloses a technical scheme, its addition can reach 30% at most. Greatly increases the dosage ratio of the lump ore in the blast furnace process, thereby reducing the operation cost of the blast furnace.

In the present invention, the rotary kiln has an inner diameter of 1 to 10m, preferably 3 to 8m, and more preferably 4 to 6 m.

In the utility model, the length of the rotary kiln is 2-200 m, preferably 5-100m, preferably 8-50m, and more preferably 12-40 m.

In the structure of the rotary kiln, the length ratio of the material distribution chamber, the shaft tube type drying and screening device and the material collection chamber is 1:0.1-100:0.5-10, preferably 1:1-70: 1-5.

In the present invention, the inner diameter of the axial tube type drying and screening device is 0.5-9.5m, preferably 1-7.5m, and more preferably 2-4.5 m.

The utility model discloses in, lump ore feed inlet sets up the feed end at the rotary kiln. The lump ore discharge port is arranged at the discharge end of the rotary kiln. The hot medium inlet is arranged at the discharge end of the rotary kiln. The heat medium outlet is arranged at the feed end of the rotary kiln and/or on the side wall of the rotary kiln. The fine material discharge port is arranged on the side wall of the rotary kiln close to the bottom of the discharge end of the rotary kiln.

Compared with the prior art, the technical scheme of the utility model following beneficial technological effect has:

1. the utility model adopts the rotary kiln to carry out drying pretreatment on lump ore, and heat medium is conveyed to the rotary kiln; in the rotary kiln, the heat medium dries the lump ore, the moisture in the lump ore is evaporated, and the lump ore is discharged out of the rotary kiln along with the heat medium after heat exchange, so that the aim of drying the lump ore is fulfilled.

2. The utility model discloses a to the shortcoming that the lump ore exists of drying in the rotary kiln, the method that the rotary kiln that adopts to have the dry screening plant of axle tubular carries out drying and screening to the lump ore, and a plurality of dry screening plant of axle tubular evenly arrange, and large granule lump ore is arranged to the material from the inner chamber of the dry screening plant of axle tubular and collects the room, and the intermediate layer cavity between the dry screening plant of axle tubular and the rotary kiln section of thick bamboo of then direct is discharged in the little granule lump ore. The heat medium and the lump ore are directly subjected to heat exchange, so that the drying effect of the lump ore in the rotary kiln is greatly improved.

3. The utility model discloses in, the piece ore deposit is at the down in-process of rotary kiln internal rotation, and the piece ore deposit is from the feed end flow direction discharge end of rotary kiln continuously, and the air current lets in from the discharge end of rotary kiln continuously, and the piece ore deposit is in the mobile state and carries out the gas-solid exchange with hot waste gas, and the hot gas flow is covered with whole rotary kiln, reduces the moisture content of piece ore deposit from this.

4. The utility model discloses screening and drying integration of lump ore, wherein the dry screening plant of axle tube formula includes predrying section and dry sieve segmentation, and the predrying section carries out preliminary drying process to the lump ore, and dry screening section sieves and further drying process to the lump ore; the subsequent screening efficiency of the lump ore subjected to the pre-drying treatment is higher, correspondingly, the air permeability of the material layer in the rotary kiln is improved after the synchronous screening, and the drying efficiency is also improved; therefore, mutual promotion is realized, and the screening efficiency and the drying efficiency are improved.

Drawings

Fig. 1 is the utility model discloses a lump ore pretreatment systems structure sketch map based on axle tubular rotary kiln.

Fig. 2 is the utility model discloses in the shaft tube formula drying and screening device division schematic diagram of predrying section and drying and screening section.

Fig. 3 is a schematic diagram of a system according to the present invention having a material distribution chamber and a material collection chamber.

Fig. 4 is a schematic structural diagram of the system of the present invention in which the heat medium outlet is disposed on the material distribution chamber and the side wall of the rotary kiln.

Fig. 5 is a distribution schematic diagram of the system of the present invention in which a plurality of axial tube type drying and screening devices are arranged.

Fig. 6 is a schematic structural view of the system of the present invention having a blast furnace and a dust removal system.

Reference numerals: 1: a rotary kiln; 101: a lump ore feed inlet; 102: discharging a lump ore; 103: a heat medium inlet; 104: a thermal medium outlet; 105: an interlayer chamber; 106: a fine material discharge port; 107: a material distribution chamber; 108: a material collection chamber; 201: a first moisture detection device; 202: a second moisture detection device; 301: a first material flow rate detection device; 401: a first material temperature detection device; 5: a shaft tube type drying and screening device; 501: a pre-drying section; 502: drying, screening and segmenting; 503: screening holes; 6: a blast furnace; 7: a dust removal system; 8: a fan; l1: a thermal medium delivery conduit; l2: a mineral aggregate conveying device; l3: the heat medium is discharged out of the pipe.

Detailed Description

The technical solution of the present invention is illustrated below, and the claimed invention includes but is not limited to the following embodiments.

A lump ore pretreatment system based on an axial tube type rotary kiln comprises a rotary kiln 1 and an axial tube type drying and screening device 5. The rotary kiln 1 is provided with a lump ore feed inlet 101 and a lump ore discharge outlet 102. The shaft tube type drying and screening device 5 is arranged in the rotary kiln 1. According to the trend of lump ore, the shaft tube type drying and screening device 5 is divided into a pre-drying section 501 and a drying and screening section 502. The pre-drying section 501 is communicated with a lump ore feeding hole 101 of the rotary kiln 1, and the drying screening section 502 is communicated with a lump ore discharging hole 102 of the rotary kiln 1. The rotary kiln 1 is also provided with a heat medium inlet 103 and a heat medium outlet 104. A heat medium delivery pipe L1 is connected to the heat medium inlet 103.

Preferably, the shaft tube type drying and screening device 5 is a tube cavity type structure with two open ends. Wherein, the pipe wall of the drying and screening section 502 of the shaft pipe type drying and screening device 5 is provided with screen holes 503. An interlayer chamber 105 is arranged between the outer wall of the shaft tube type drying and screening device 5 and the inner wall of the rotary kiln 1. The dry screen section 502 is in communication with the sandwiched chamber 105 through screen openings 503. The interlayer chamber 105 is also provided with a fine material discharge opening 106. The fine material discharge port 106 is provided on the side wall of the rotary kiln 1 at a position close to the lump ore discharge port 102. Namely, the fine material discharge port 106 is provided on the side wall of the rotary kiln 1, and the fine material discharge port 106 is communicated with the interlayer chamber 105.

Preferably, the screen openings 503 are evenly distributed on the wall of the dry screen section 502. The aperture of the screen hole 503 is 5 to 20mm, preferably 6 to 15mm, and more preferably 7 to 10 mm.

Preferably, the feed end of the rotary kiln 1 is provided with a material distribution chamber 107, and the discharge end of the rotary kiln 1 is provided with a material collection chamber 108. The shaft tube type drying and screening device 5 is positioned between the material distribution chamber 107 and the material collection chamber 108. The lump ore feed port 101 is provided in the material distribution chamber 107, and the lump ore discharge port 102 is provided in the material collection chamber 108. Wherein: lump ore enters the material distribution chamber 107 from the lump ore feed inlet 101 and then passes through the shaft tube type drying and screening device 5 and enters the material collection chamber 108. At the same time, the powder attached to the lump ore enters the interlayer chamber 105 through the screen holes 503 on the pipe wall of the dry screen section 502 and is then discharged from the fine material discharge port 106. The heat medium inlet 103 is arranged on the material collection chamber 108. The thermal medium outlet 104 is provided on the material distribution chamber 107. The heat medium enters the rotary kiln 1 from a heat medium inlet 103 on the material collection chamber 108, directly contacts with lump ore for heat exchange, reversely flows through the shaft tube type drying and screening device 5 and then is discharged from a heat medium outlet 104 on the material distribution chamber 107.

Preferably, the feed end of the rotary kiln 1 is provided with a material distribution chamber 107, and the discharge end of the rotary kiln 1 is provided with a material collection chamber 108. The shaft tube type drying and screening device 5 is positioned between the material distribution chamber 107 and the material collection chamber 108. The lump ore feed port 101 is provided in the material distribution chamber 107, and the lump ore discharge port 102 is provided in the material collection chamber 108. Wherein: lump ore enters the material distribution chamber 107 from the lump ore feed inlet 101 and then passes through the shaft tube type drying and screening device 5 and enters the material collection chamber 108. At the same time, the powder attached to the lump ore enters the interlayer chamber 105 through the screen holes 503 on the pipe wall of the dry screen section 502 and is then discharged from the fine material discharge port 106. The material collection chamber 108 is provided with a heat medium inlet 103. The material distribution chamber 107 and the rotary kiln 1 are provided with a heat medium outlet 104 on the side wall. Also, the heat medium outlet 104 on the side wall of the rotary kiln 1 is located near the pre-drying section 501.

The heat media are respectively: firstly, the heat medium enters the rotary kiln 1 from a heat medium inlet 103 on a material collecting chamber 108, directly contacts with lump ore for heat exchange, reversely flows through a shaft tube type drying and screening device 5, and then is discharged from a heat medium outlet 104 on a material distributing chamber 107.

Secondly, the hot medium enters the rotary kiln 1 from a hot medium inlet 103 on the material collecting chamber 108, directly contacts with lump ore for heat exchange, reversely flows through the shaft tube type drying and screening device 5, enters the interlayer chamber 105 through screen holes 503 on the tube wall of the drying and screening section 502, and is discharged from a hot medium outlet 104 on the side wall of the rotary kiln 1.

Preferably, the system comprises a plurality of said shaft tube type drying and screening devices 5. A plurality of shaft tube type drying and screening devices 5 are arranged inside the rotary kiln 1. The feed inlets of all the shaft tube type drying and screening devices 5 are communicated with the material distribution chamber 107. The discharge ports of all the shaft tube type drying and screening devices 5 are communicated with the material collecting chamber 108.

Preferably, the number of the shaft tube type drying and screening devices 5 is 1-20, preferably 2-15, more preferably 3-10.

Preferably, a first moisture detection device 201, a first material flow rate detection device 301 and a first material temperature detection device 401 are arranged at the lump ore feed inlet 101 on the rotary kiln 1.

Preferably, the second moisture detection device 202 is disposed at the lump ore discharge port 102 of the rotary kiln 1.

Preferably, the rotary kiln 1 is arranged obliquely, and the feeding end of the rotary kiln 1 is positioned at a horizontal position higher than the discharging end of the rotary kiln 1. Preferably, the inclination angle of the rotary kiln 1 is 0-60 degrees, preferably 2-45 degrees, and more preferably 5-30 degrees.

Preferably, the system further comprises a blast furnace 6, and the lump ore discharge port 102 is connected to the feed port of the blast furnace 6 through an ore material conveying device L2.

Preferably, the system further includes a dust removal system 7, and the heat medium outlet 104 is communicated to the dust removal system 7 through a heat medium discharge pipe L3.

Preferably, the system further includes a fan 8, and the fan 8 is disposed on the heat medium discharge pipe L3.

Example 1

As shown in fig. 1-2, a lump ore pretreatment system based on an axial tube type rotary kiln comprises a rotary kiln 1 and an axial tube type drying and screening device 5. The rotary kiln 1 is provided with a lump ore feed inlet 101 and a lump ore discharge outlet 102. The shaft tube type drying and screening device 5 is arranged in the rotary kiln 1. According to the trend of lump ore, the shaft tube type drying and screening device 5 is divided into a pre-drying section 501 and a drying and screening section 502. The pre-drying section 501 is communicated with a lump ore feeding hole 101 of the rotary kiln 1, and the drying screening section 502 is communicated with a lump ore discharging hole 102 of the rotary kiln 1. The rotary kiln 1 is also provided with a heat medium inlet 103 and a heat medium outlet 104. A heat medium delivery pipe L1 is connected to the heat medium inlet 103.

Example 2

Example 1 is repeated except that the shaft tube type drying and screening device 5 is a tube cavity type structure with two open ends. Wherein, the pipe wall of the drying and screening section 502 of the shaft pipe type drying and screening device 5 is provided with screen holes 503. An interlayer chamber 105 is arranged between the outer wall of the shaft tube type drying and screening device 5 and the inner wall of the rotary kiln 1. The dry screen section 502 is in communication with the sandwiched chamber 105 through screen openings 503. The interlayer chamber 105 is also provided with a fine material discharge opening 106. The fine material discharge port 106 is provided on the side wall of the rotary kiln 1 at a position close to the lump ore discharge port 102. Namely, the fine material discharge port 106 is provided on the side wall of the rotary kiln 1, and the fine material discharge port 106 is communicated with the interlayer chamber 105. The screen openings 503 are evenly distributed on the wall of the dry screen section 502. The aperture of the sieve hole 503 is 10 mm.

Example 3

Example 2 was repeated except that the mesh opening 503 had a diameter of 8 mm.

Example 4

Example 2 was repeated except that the mesh opening 503 had a diameter of 5 mm.

Example 5

Example 4 was repeated, as shown in fig. 3, except that the feed end of the rotary kiln 1 was provided with a material distribution chamber 107 and the discharge end of the rotary kiln 1 was provided with a material collection chamber 108. The shaft tube type drying and screening device 5 is positioned between the material distribution chamber 107 and the material collection chamber 108. The lump ore feed port 101 is provided in the material distribution chamber 107, and the lump ore discharge port 102 is provided in the material collection chamber 108. Wherein: lump ore enters the material distribution chamber 107 from the lump ore feed inlet 101 and then passes through the shaft tube type drying and screening device 5 and enters the material collection chamber 108. At the same time, the powder attached to the lump ore enters the interlayer chamber 105 through the screen holes 503 on the pipe wall of the dry screen section 502 and is then discharged from the fine material discharge port 106. The heat medium inlet 103 is arranged on the material collection chamber 108. The thermal medium outlet 104 is provided on the material distribution chamber 107. The heat medium enters the rotary kiln 1 from a heat medium inlet 103 on the material collection chamber 108, directly contacts with lump ore for heat exchange, reversely flows through the shaft tube type drying and screening device 5 and then is discharged from a heat medium outlet 104 on the material distribution chamber 107.

Example 6

Example 4 was repeated, as shown in fig. 4, except that the feed end of the rotary kiln 1 was provided with a material distribution chamber 107 and the discharge end of the rotary kiln 1 was provided with a material collection chamber 108. The shaft tube type drying and screening device 5 is positioned between the material distribution chamber 107 and the material collection chamber 108. The lump ore feed port 101 is provided in the material distribution chamber 107, and the lump ore discharge port 102 is provided in the material collection chamber 108. Wherein: lump ore enters the material distribution chamber 107 from the lump ore feed inlet 101 and then passes through the shaft tube type drying and screening device 5 and enters the material collection chamber 108. At the same time, the powder attached to the lump ore enters the interlayer chamber 105 through the screen holes 503 on the pipe wall of the dry screen section 502 and is then discharged from the fine material discharge port 106. The material collection chamber 108 is provided with a heat medium inlet 103. The material distribution chamber 107 and the rotary kiln 1 are provided with a heat medium outlet 104 on the side wall. Also, the heat medium outlet 104 on the side wall of the rotary kiln 1 is located near the pre-drying section 501.

Example 7

Example 6 was repeated as shown in figure 5 except that the system included a plurality of said shaft tube type drying and screening devices 5. A plurality of shaft tube type drying and screening devices 5 are arranged inside the rotary kiln 1. The feed inlets of all the shaft tube type drying and screening devices 5 are communicated with the material distribution chamber 107. The discharge ports of all the shaft tube type drying and screening devices 5 are communicated with the material collecting chamber 108. The number of the shaft tube type drying and screening devices 5 is 4.

Example 8

Example 7 was repeated except that the lump ore feed port 101 of the rotary kiln 1 was provided with a first moisture detecting means 201, a first material flow rate detecting means 301 and a first material temperature detecting means 401, as shown in fig. 6.

Example 9

Example 8 is repeated, and the lump ore discharge port 102 of the rotary kiln 1 is provided with the second moisture detecting device 202.

Example 10

Example 9 was repeated except that the rotary kiln 1 was inclined with the feed end of the rotary kiln 1 lying at a higher level than the discharge end of the rotary kiln 1. The inclination angle of the rotary kiln 1 is 10 degrees.

Example 11

Example 10 was repeated except that the system further included a blast furnace 6, and the lump ore discharge port 102 was connected to the feed port of the blast furnace 6 through an ore conveying device L2.

Example 12

Repeating the embodiment 11, the system further includes the dust removing system 7, and the heat medium outlet 104 is communicated to the dust removing system 7 through the heat medium discharge pipe L3.

Example 13

Embodiment 12 is repeated except that the system further includes a fan 8, and the fan 8 is disposed on the heat medium discharge pipe L3.

Example 14

Example 1 was repeated except that the inside diameter of the axial tube type drying and screening device 5 was 4 m.

Example 15

Example 1 was repeated except that the inside diameter of the axial tube type drying and screening device 5 was 8 m.

By adopting the lump ore pretreatment system based on the shaft tube type rotary kiln, the dried large-particle lump ore obtained after pretreatment is conveyed to the blast furnace, the addition amount of the lump ore can be increased to 30-35% in the raw material added to the blast furnace, and the smelting cost of the blast furnace can be reduced by about 12 yuan/ton molten iron in unit time; 2500m³The annual cost of the blast furnace is saved by 2160 ten thousand yuan.

In addition, because the iron content in the lump ore is higher than that of the sintered ore and the pellet ore, the addition amount of the pretreated lump ore is increased in the blast furnace, and the yield of the obtained molten iron can be increased by 10-30% through a blast furnace smelting process.

Claims

1. The utility model provides a lump ore pretreatment systems based on axle tubular rotary kiln which characterized in that: the system comprises a rotary kiln (1) and a shaft tube type drying and screening device (5); a lump ore feed inlet (101) and a lump ore discharge outlet (102) are arranged on the rotary kiln (1); the shaft tube type drying and screening device (5) is arranged in the rotary kiln (1); according to the trend of lump ore, the shaft tube type drying and screening device (5) is divided into a pre-drying section (501) and a drying and screening section (502); the pre-drying section (501) is communicated with a lump ore feeding hole (101) of the rotary kiln (1), and the drying screening section (502) is communicated with a lump ore discharging hole (102) of the rotary kiln (1); the rotary kiln (1) is also provided with a heat medium inlet (103) and a heat medium outlet (104); a heat medium conveying pipeline (L1) is connected to the heat medium inlet (103); wherein, the inner diameter of the shaft tube type drying and screening device (5) is 0.5-9.5 m.

2. The system of claim 1, wherein: the shaft tube type drying and screening device (5) is of a tube cavity type structure with two open ends; wherein, the pipe wall of the drying and screening section (502) of the shaft pipe type drying and screening device (5) is provided with a screen hole (503); an interlayer chamber (105) is arranged between the outer wall of the shaft tube type drying and screening device (5) and the inner wall of the rotary kiln (1); the drying screen section (502) is communicated with the interlayer chamber (105) through screen holes (503); the interlayer chamber (105) is also provided with a fine material discharge port (106); the fine material discharge port (106) is arranged on the side wall of the rotary kiln (1) and is positioned close to the lump ore discharge port (102).

3. The system of claim 2, wherein: the screen holes (503) are uniformly distributed on the pipe wall of the drying screen section (502); the aperture of the sieve holes (503) is 5-20 mm.

4. The system of claim 3, wherein: the aperture of the sieve holes (503) is 6-15 mm.

5. The system of claim 4, wherein: the aperture of the sieve holes (503) is 7-10 mm.

6. The system according to any one of claims 2-5, wherein: a material distribution chamber (107) is arranged at the feed end of the rotary kiln (1), and a material collection chamber (108) is arranged at the discharge end of the rotary kiln (1); the shaft tube type drying and screening device (5) is positioned between the material distribution chamber (107) and the material collection chamber (108); the lump ore feed inlet (101) is arranged on the material distribution chamber (107), and the lump ore discharge outlet (102) is arranged on the material collection chamber (108).

7. The system according to any one of claims 2-5, wherein: a material distribution chamber (107) is arranged at the feed end of the rotary kiln (1), and a material collection chamber (108) is arranged at the discharge end of the rotary kiln (1); the shaft tube type drying and screening device (5) is positioned between the material distribution chamber (107) and the material collection chamber (108); the lump ore feed inlet (101) is arranged on the material distribution chamber (107), and the lump ore discharge outlet (102) is arranged on the material collection chamber (108).

8. The system of claim 6, wherein: the system comprises a plurality of shaft tube type drying and screening devices (5); the plurality of shaft tube type drying and screening devices (5) are all arranged inside the rotary kiln (1); the feed inlets of all the shaft tube type drying and screening devices (5) are communicated with a material distribution chamber (107); the discharge ports of all the shaft tube type drying and screening devices (5) are communicated with a material collecting chamber (108).

9. The system of claim 7, wherein: the system comprises a plurality of shaft tube type drying and screening devices (5); the plurality of shaft tube type drying and screening devices (5) are all arranged inside the rotary kiln (1); the feed inlets of all the shaft tube type drying and screening devices (5) are communicated with a material distribution chamber (107); the discharge ports of all the shaft tube type drying and screening devices (5) are communicated with a material collecting chamber (108).

10. The system according to claim 8 or 9, characterized in that: the number of the shaft tube type drying and screening devices (5) is 1-20.

11. The system of claim 10, wherein: the number of the shaft tube type drying and screening devices (5) is 2-15.

12. The system of claim 11, wherein: the number of the shaft tube type drying and screening devices (5) is 3-10.

13. The system of any one of claims 1-5, 8-9, 11-12, wherein: a first moisture detection device (201), a first material flow detection device (301) and a first material temperature detection device (401) are arranged at a lump ore feed inlet (101) on the rotary kiln (1); and/or

A second moisture detection device (202) is arranged at the lump ore discharge hole (102) of the rotary kiln (1).

14. The system of claim 6, wherein: a first moisture detection device (201), a first material flow detection device (301) and a first material temperature detection device (401) are arranged at a lump ore feed inlet (101) on the rotary kiln (1); and/or

15. The system of claim 7, wherein: a first moisture detection device (201), a first material flow detection device (301) and a first material temperature detection device (401) are arranged at a lump ore feed inlet (101) on the rotary kiln (1); and/or

16. The system of any one of claims 1-5, 8-9, 11-12, wherein: the rotary kiln (1) is obliquely arranged, and the horizontal position where the feeding end of the rotary kiln (1) is located is higher than the discharging end of the rotary kiln (1).

17. The system of claim 6, wherein: the rotary kiln (1) is obliquely arranged, and the horizontal position where the feeding end of the rotary kiln (1) is located is higher than the discharging end of the rotary kiln (1).

18. The system of claim 7, wherein: the rotary kiln (1) is obliquely arranged, and the horizontal position where the feeding end of the rotary kiln (1) is located is higher than the discharging end of the rotary kiln (1).

19. The system of claim 16, wherein: the inclination angle of the rotary kiln (1) is 0-60 degrees.

20. The system of claim 17, wherein: the inclination angle of the rotary kiln (1) is 0-60 degrees.

21. The system of claim 18, wherein: the inclination angle of the rotary kiln (1) is 0-60 degrees.

22. The system according to any one of claims 19-21, wherein: the inclination angle of the rotary kiln (1) is 2-45 degrees.

23. The system of claim 22, wherein: the inclination angle of the rotary kiln (1) is 5-30 degrees.

24. The system of any one of claims 1-5, 8-9, 11-12, 14-15, 17-21, 23, wherein: the system also comprises a blast furnace (6), and the lump ore discharge port (102) is connected to the feed port of the blast furnace (6) through an ore material conveying device (L2).

25. The system of claim 6, wherein: the system also comprises a blast furnace (6), and the lump ore discharge port (102) is connected to the feed port of the blast furnace (6) through an ore material conveying device (L2).

26. The system of claim 7, wherein: the system also comprises a blast furnace (6), and the lump ore discharge port (102) is connected to the feed port of the blast furnace (6) through an ore material conveying device (L2).

27. The system of any one of claims 1-5, 8-9, 11-12, 14-15, 17-21, 23, 25-26, wherein: the system further comprises a dust removal system (7), and the heat medium outlet (104) is communicated to the dust removal system (7) through a heat medium discharge pipeline (L3).

28. The system of claim 6, wherein: the system further comprises a dust removal system (7), and the heat medium outlet (104) is communicated to the dust removal system (7) through a heat medium discharge pipeline (L3).

29. The system of claim 7, wherein: the system further comprises a dust removal system (7), and the heat medium outlet (104) is communicated to the dust removal system (7) through a heat medium discharge pipeline (L3).

30. The system of claim 27, wherein: the system further includes a fan (8), and the fan (8) is disposed on the heat medium discharge pipe (L3).

31. The system of claim 28 or 29, wherein: the system further includes a fan (8), and the fan (8) is disposed on the heat medium discharge pipe (L3).