Limestone with proper granularity first enters the preheater of kiln.the limestone is preheated to about 900 DEG C in the preheater by the flue gas of 1000-1100 DEG C from the tail of the rotary kiln,About 10%-20% of limestone is decomposed.The preheated limestone enters the Limestone rotary kiln through the chute,the limestone is further heated in a kiln,continue to decompose at a temperature of 1200-1250 DEG C,until completely calcined.The calcined lime discharged from the kiln head, then fall into the kiln cooler for cooling.When the lime falls into the cooler, the temperature is about 100 DEG C, the cold air which is blown from the bottom of the cooler is used to cool the lime to 40-100 DEG C,after cooling, the lime is discharged from the ash discharging device.Limestone rotary kiln is usually controlled by microcomputer,the operation is completely automatic from adding limestone to discharging calcined lime.
The raw materials used in the production of metallurgical lime are limestone, whose mineral composition is mainly calcite (CaCO3), and occasionally dolomite.The chemical composition, mineral composition and physical properties of limestone change with the length of the formation time, the longer the formation of lime, the more dense, hard, the shorter the formation time, the more loose the structure.As the raw material of metallurgical lime, its quality depends on its structure, composition and content of impurities, and the distribution of impurities in limestone.In general,the impurity which are easy to cause the difficulties on the calcination process are: SiO2, AL2O3, Fe2O3, K2O etc..Limestone with impurity content greater than 4-5%, or alkali metal content greater than 011%-012%, has the possibility to form various low melting point compounds.The lime is partially or wholly over the firing temperature,blocking the pores which are lives as the releasing pathway of the CO2,blocking the decomposition of limestone.Fuels used in rotary kilns are solid, liquid and gaseous fuels.The solid fuel has a certain effect on the activity of lime because of the high impurity content,,but from fuel diversification, solid fuel is indispensable, most of our ordinary kiln is still using solid fuel.Liquid fuels are rarely used because of shortages. It is very advantageous to choose the gas fuel, which is convenient and can improve the activity of lime.According to the change of kiln type and fuel market price, the fuel used in lime kiln is also changing.
There are free calcium oxide and combined calcium oxide in lime composition,the free calcium oxide is also divided into Active calcium oxide and non active calcium oxide.Under the condition of general digestion, non active calcium oxide can not react with water, but it may be converted to active calcium oxide (such as after grinding).Active calcium oxide is the part of the free calcium oxide which can react with water under the common conditions.Combined calcium oxide is not reversible, so it can not be called inactive calcium oxide.The reaction capacity of lime can be regarded as the number of active calcium oxide in the total amount of free calcium oxide.Calcination of limestone is a transitional process that a diamond-shaped lattice of limestone that crystallizes into a cubic lattice of lime.The crystal structure obtained from the change is related to the formation of the new crystal nucleus and its growth rate.When the current is larger than that of the latter, the crystal grains are obtained, and the number of active calcium oxide molecules is high,on the contrary,the coarse crystals with low surface energy are obtained,It has a small number of active calcium oxide molecules.The limestone is calcined at low temperature, and the obtained lime is a fine crystal structure,it is the active lime.Therefore, it is characterized by small grain size, high porosity, small bulk density and large specific surface area.In addition to the effect of calcination temperature, calcination time extension will make the lime grain significantly increased, is not conducive to the generation of active lime.The active lime has the advantages of fast slag forming speed and strong reactivity, and is more suitable for the converter steelmaking, the refining of molten steel and the pretreatment of hot metal. Therefore, the use of active lime has become a trend in the development of iron and steel metallurgy.
Lime rotary kiln is also called roller rotary kiln. To make sure its air leakage coefficient is less than 10 percent, lime rotary kiln adopts advanced structure and reliable combined scale-like seal in both ends. It also uses composite refractory to reduce the loss of heat radiation.
Lime rotary kilns whole process is well-regulated. The limestone is stored in a silo. Then be carried in preheaters top silo by hoist. There are two-level gauges in silo to control the feed amount. They distribute limestone evenly into different preheaters rooms through feed pipe.
Limestone is decomposed 30% when it is heated to 900 by hot smoke at 1150 . After being pushed into the kiln by a hydraulic push rod, lime is resolved into CaO and CO2. Then be cooled down to 100 by cold air in cooler and then be discharged.
After successively through vibrating feeder, chain bucket conveyor, bucket elevator and tape conveyor, lime eventually is sent into lime finished product library. Then the clients decide whether screening is needed.
Lime rotary kiln has a reliable combined scale-like seal. The scale-like seal in both ends guarantees its air leakage coefficient is less than 10 percent. It also uses composite refractory to reduce the loss of heat radiation.
Lime rotary kiln has a vertical cooler. The filled cooler with dividable ventilation cools down the lime into 80 making it easier to be transported and stored. And it can preheat the secondary kiln air up to more than 700, which reduces the need for moving parts and special materials.
3. Pay attention to the details of the lime rotary kiln below. The gradient of preheater and precalciner should be 3.5%-4%. Precalciners maximum speed should be 3.0-3.5r/min while preheaters should be 2.0-2.5r/min. The speed range should be 1:10.
The lime rotary kiln is a calcining property for limestone and is mainly used for the main equipment used in the lime production line. This type of rotary kiln (optional with vertical preheater and vertical cooler to form energy-saving rotary kiln calcination system) has high raw material utilization rate, complete calcination, uniform quality, good quality, large production capacity, high operation rate, energy saving and environmental protection. The operation is simple, and the life of the whole machine is long, which is in line with the national environmental protection policy.
The output of rotary kiln is very high, which is very suitable for large-scale active lime production line; many 150-600 tons of lime rotary kiln with daily production have been built at home and abroad, which is in good working condition and suitable for small and medium-sized lime enterprises.
The rotary kiln is open-type calcination. The structure of the kiln is simple, the airflow is smooth, and the sulfur-containing flue gas can be discharged in time. The sulfur in the fuel is not easy to adhere, so the product has low sulfur content and meets the steelmaking requirements. At the same time, the material rolls evenly in the kiln, the heat is uniform, the product quality is stable, the raw and over-burning rate is very low, and the lime for steelmaking with high activity can be calcined. Under the same conditions, the activity of lime produced by rotary kiln is higher than that of gas-fired kiln, with an average height of more than 30ml, and the activity is generally 340-380ml, even up to 400ml;
The rotary kiln can directly calcine 10-50mm fine-grained limestone. The general mine product 0-30mm fine-grained limestone accounts for 30-40% of the total output. This part of limestone can not be used. And with the "fine materialization" of steel raw materials, sintering gradually replaces limestone with quicklime, and fine-grained limestone cannot be comprehensively utilized. The construction of rotary kiln production line can not only make full use of high-quality limestone mine resources, but also meet the sustainable development policy of lime industry;
The vertical preheater at the kiln tail can make full use of the high temperature flue gas generated by calcination in the rotary kiln, and preheat the limestone from the normal temperature to the initial decomposition state. This not only greatly increases the output of the rotary kiln, but also reduces the heat consumption per unit of product;
The vertical cooler at the kiln head can not only quench the high temperature lime, but also increase the activity of the product, and also change to transport and storage. At the same time, it can get the secondary air entering the kiln at a higher temperature. It can effectively increase the firing temperature in the kiln and reduce fuel consumption;
The temperature of the flue gas discharged through the vertical preheater of the kiln is low, between 280-350 C, and the dust content is low, about 20g/Nm3, which makes the configuration of the subsequent flue gas treatment simple and effective, and can smoothly meet the environmental protection requirements;
The stable quality of the rotary kiln lime is its greatest advantage, preheating the limestone from normal temperature to the initial decomposition state. This not only greatly increases the output of the rotary kiln, but also reduces the heat consumption per unit of product.
Lime rotary kiln has many advantages in the processing of limestone ore, it is also known as the lime kiln, is a professional strong calcining equipment, its main advantage include great production capacity, no noise, low energy consumption and so on. As the main equipment of lime production line, it has very high industrial value, so the demand for the lime rotary kiln is very high, and becomes the ideal equipment for the masses of users in the lime processing.
Aiming at the calcination characteristics of limestone, a new type of cement kiln for active lime has been developed on the basis of absorbing and learning from similar rotary kilns at home and abroad.
The lime rotary kiln produced by AGICO CEMENT has the characteristics of the high utilization rate of raw materials, uniform quality, good quality, large capacity, high turnover rate, and easy operation.
Limestone is fed into the kiln through the chute at the end of the kiln. Due to the tilt and slow rotation of the kiln body, the limestone rolls along the circumference on one side and moves from the end of the kiln to the kiln head on the other side along the axis. The fuel is sprayed into the kiln from the end of the kiln through the burner for combustion, and the heat is transmitted to the limestone by radiation, convection and conduction. After the limestone is calcined into quicklime during the moving process, it is discharged from the end of the kiln, and the high-temperature flue gas enters the dust removal system from the end of the kiln.
According to the fuel, lime kiln is divided into mixed kilns (namely burning solid fuel, coke, coke powder, coal, etc.) and Gas kiln. Gas kilns include blast furnace gas, coke oven gas, calcium carbide tail gas, producer gas, natural gas, etc.
INTRODUCTION Active lime is produced from limestone, dolomite, chalk and other minerals with high calcium carbonate content by the calcination process under the temperature of 1000-1100 C. There are various processes for the active lime production, mainly including: Advanced 'Preheater-Rotary kiln-Vertical cooler' energy-saving process, Traditional 'long rotary lime kiln' process, Mixed buring vertical kiln process, Gas-red or oil-red vertical kiln process. The selection of the active lime production project is effected by many factors, such as : the activity requirement, the fuel, the limestone sizes, production capacity, environmental-protection requirement. Low Investment Cost Cement Lime Limestone Shaft Kiln Furnace for Sale Mixed Burning Vertical Lime Kiln Process The qualified raw materials and solid fuels are mixed uniformly according to a certain proportion and then sent to the vertical kiln through a single bucket elevator for calcination. After calcination, the final lime products are discharged from the bottom of the vertical kiln through a discharge device to the conveyor, and the conveyor sends the final lime products to the storage silo. The hot flue gas generated by calcination will firstly go into the dust collecting system, and then the clean flue gas will be emitted through chimney to the atmosphere. Sudan 100TPD Actice Lime Plant Project Description: This Buyer is located in North Sudan. The final product of this plant is used for steel plant. Shaft kiln is taken for it and the production capacity is 100TPD. Screen Plate details according to the buyer's requirement: Fuel:LPG and Diesel Raw Material Size:300mm Production Capacity:100TPD Heat Value of LPG:11.500 kcal/kg. Service provided to client during this process: 1. Initial Design was provided according to the clients requirement and then the contract was signed after the initial design is approved by the buyer. 2. After the down payment was available to our account, the final design was made and provided which was also agreed by the buyer. 3. All the equipment were put into production and good-quality product are ensured. Through continuous communication, the trust from client was enjoyed by us. And our factory was also thought highly by client which contributed a lot to the contract signing. We will select the most workable and ecient and economical solution based o the clients' specic requirement and conditions.
INTRODUCTION Active lime is produced from limestone, dolomite, chalk and other minerals with high calcium carbonate content by the calcination process under the temperature of 1000-1100 C. There are various processes for the active lime production, mainly including: Advanced 'Preheater-Rotary kiln-Vertical cooler' energy-saving process, Traditional 'long rotary lime kiln' process, Mixed buring vertical kiln process, Gas-red or oil-red vertical kiln process. The selection of the active lime production project is effected by many factors, such as : the activity requirement, the fuel, the limestone sizes, production capacity, environmental-protection requirement. Low Investment Cost Cement Lime Limestone Shaft Kiln Furnace for Sale
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Rotary lime kiln is also called lime rotary kiln or limestone rotary kiln. It is used for the calcination of limestone to make quicklime. And specifically speaking, it is a slightly horizontal device that can rotate continuously to burn down the limestone thoroughly to make quicklime. Lime rotary kiln, along with vertical lime kiln, is the core equipment for lime calcination plant. Daswell provides customized rotary lime kiln with great durability, reliability and great performance. And to improve cost-efficiency and energy-efficiency, Daswell also offers vertical preheater and vertical cooler to work along with our limestone rotary kiln. In fact, Daswell offers tailor-made turnkey solutions for quicklime plant, including designing, planning and supplying the complete set of equipment.
Henan Daswell machinery is a professional supplier of rotary lime kiln. In fact, Daswell offers end-to-end solutions for lime calcination plant, including initial designing, planning, providing complete set of equipment and after-sales services. And Daswell has finished several successful quicklime plants projects worldwide. As for the rotary lime kiln, it is the core equipment for quicklime production plant. Daswell limestone rotary kiln are customized designed and manufactured to meet customers needs. For different production capacity needs, Daswell lime rotary kiln can come in different diameters. Daswell rotary kilns for lime calcination are of robust designs with quality materials so that they can work for long term with great performance. Besides, to ensure the high cost-efficiency of lime calcination plant, Daswell also offers vertical pre-heater and vertical coolers to work with the lime rotary kiln.
Limestone contains mainly of calcium carbonate. And when limestone is strongly heated in rotary kiln, calcium carbonate undergoes thermal decomposition to form calcium oxide, which is quicklime, and carbon dioxide (CO). This reaction takes place at 900, but the temperature in rotary lime kiln is often around 1000 degrees to make the process happen quickly. But excessive temperature is avoided because it produces unreactive, dead-burnedlime. Rotary lime kiln rotates continuously on riding rings for a period of time so that the limestone can be burnt down thoroughly. During the operation of rotary lime kiln, quicklime will be left inside, with carbon dioxide being driven off.
Rotary kiln for lime production is a central equipment for quicklime plant. In fact, it has long been used for making quicklime. And the design of limestone rotary lime has been constantly designed and innovated with the improvement of high technology as well as the great materials. Daswell modern rotary lime kilns are made of high quality materials with high technology. It is a rotating cylindrical vessel. And it is slightly inclined to horizontal, with the higher end being the material inlet and lower end to discharge quicklime. As a result, the processed limestone in the rotary lime kiln will move to lower end to be discharged. Its shell is often made of rolled mild steel plates which are welded to form a cylinder. And the lengths and diameters of the cylinder vary from each other depending on the needs of customers. Daswell provides limestone lime kiln with length ranging 40-72m, while the diameter ranging 2.5-5.24m. Daswell rotary lime kilns tend to shorter because they can work with vertical preheater and vertical cooler.
Except for the rotary lime kiln vessel itself, there are other parts which can be important for the limestone lime kiln. For example, the refractory lining inside the kiln shell, riding rings, rollers, and furnace and so on. As for the refractory lining, it is used to insulate the lime kiln shell from the high temperature in the rotary lime kiln, and also protects the shell from the corrosive property of the processed material. For the riding rings, they are made of quality steel casting and are uniquely designed to fit the shell snugly and allow the smooth movement of the rotary lime kiln. And the rollers are used to support the limestone rotary kiln and allow the smooth rotating of the lime rotary kiln. The furnace is at and the lower end of lime rotary kiln. Through the furnace, fuel, such as oil and gas, will burn the limestone in kiln with high temperature.
How does a rotary lime kiln work? Daswell rotary lime kiln often works with vertical preheater and vertical cooler. So the lime rotary kiln process will include the process of preheater and cooler. Firstly, quarried limestone will be further crushed, sifted and washed to be proper feed material with required sizes. Then the limestone will be transferred to vertical preheater through bucket elevator. In the preheater, the limestone will be preheated by the exhaust hot air from the rotary lime kiln. For the limestone in the rotary lime kiln moves in counter current with the air flow in the kiln. And the preheated limestone will go into the rotary lime kiln for calcination. The rotary lime kiln will rotate constantly for a period of time to burn through the limestone. At the end, the burnt lime will be discharged into the cooler to cool down. Finally, the quicklime then will be stored in product silo. Please fill the form below to get free quotes. We will reply in 24 hours. Product Model: Your Name(required): Your Email(required): Your Tel: Your country: Your Company: Your Message(required):