Used Belt-type Sinterer its process and advantages

The belt sintering machine is suitable for sintering operations in large-scale ferrous metallurgical sintering plants.It is the main equipment in the extraction sintering process.It can sinter concentrate powder and rich ore powder with different components and particle sizes into blocks,and partially remove harmful impurities such as sulfur,phosphorus,and arsenic contained in the ore.Scope of supply,trolley,head star wheel device,tail star wheel device,frame,head rail,middle rail,tail rail,roller distributor,igniter,flexible transmission device,suction device,head and tail sealing device,tail Mobile device,large flue ash unloading device,electric control system and a complete set of drawings.

Sintering plant 

Sintering plants agglomerate iron ore fines (dust) with other fine materials at high temperatures to make products that can be used in blast furnaces.The final product,sinter,is small irregular nodules of iron mixed with small amounts of other minerals.This process,called sintering,fuses the constituent materials into a single porous mass with little change in the chemical properties of the constituents.The purpose of sintering is to convert iron into steel.Sinter plants are combined with blast furnaces and are also used for non-ferrous metal smelting.About 70% of the world's primary lead production is still produced using a sinter plant-blast furnace combination,which was previously often used for copper smelting (at the electrolytic refining and smelting smelter in Wollongong, NSW.

Process

Ore preparation

The main feed to the sinter plant is a base mix consisting of iron ore fines,coke fines and flux (limestone) fines.In addition to the base mixture,coke fines,flux powders,sinter fines,iron fines (collected from the plant dedusting system and ESP) and plant waste are mixed in proportion (by weight) in a drum,commonly known as a mixing and spheroidizing drum.Calcined lime is used together with water as a binder for the mixed material (all in specific weight ratios) to form the feed sinter with a size of about 5 to 7 mm. The sinter balls are fed into a sinter machine where they are burned to produce blast furnace feed sinter.

Sintered material

The material is placed on the sintering machine in two layers.The thickness of the bottom layer may vary from 30 to 75 mm (1.2 to 3.0 inches).A sintered section of 12 to 20 mm is used,also known as the hearth floor.Second,the cover consists of a mix of materials with a total bed height of 350 to 660 mm (14 to 26 inches).The mixed material is applied by means of a drum feeder and a roller feeder,distributing the pellets at a certain depth throughout the sintering machine.Use a leveler to smooth the upper layer.The material,also known as charge,enters the ignition furnace into rows of multi-slot burners.In the case of a plant, there are eleven burners in the first (ignition) zone.The next (soaking/annealing) zone typically provides 12 burners.Throughout the sintering machine,air is sucked in from the bottom of the mixed material bed.The fire gradually penetrates the mixed material until it reaches the hearth level.The end of this combustion is called the burn-through point (BTP).The hearth layer is only sinter of smaller size,limiting the adhesion of hot sinter to the pallet.BTP is implemented in a certain area of the sintering machine to optimize the process by means of multiple temperature measuring instruments placed throughout the sintering machine.After the combustion is complete,the mixture is transformed into sinter,which is then crushed into smaller sizes by the sinter crusher.After being broken into small sizes, it is cooled in coolers (linear or circular) by forced air.At the outlet of the sinter cooler,the sintering temperature is kept low so that the hot sinter can be transported by a conveyor belt made of rubber.Take the necessary precautions to trace the presence of a fire in the conveyor belt and extinguish the fire as necessary by spraying water. The product is then passed through a jaw crusher where the sinter is further reduced in size (~ 50 mm) into smaller sizes.Then pass the complete mixture through two sieves.The smallest sinter fines (< 5mm) are stored in the batching silo and are reused to prepare sinter through the mixing and spheroidizing drums before being sent to the sintering machine for combustion.A smaller part (5 – 20 mm) is used for the hearth level of the sintering machine,the rest is sent to the blast furnace together with the largest size sinter.The temperature in the ignition zone is usually kept between 1,150 and 1,250 °C (2,100 and 2,280 °F),and the temperature in the soaking zone is usually kept between 900 and 1000 °C to prevent sudden quenching of the sintered layer.The 5 mm portion from the top of the screen enters the conveyor belt carrying the blast furnace sinter and enters the sinter storage silo or BF silo together with the blast furnace grade sinter.Blast furnace grade sinter consists of particles 5 to 12 mm and 20 mm and larger.

Advantages

Using sinter has certain advantages over using other materials,including the recovery of fines and other waste products including flue ash,scale,lime powder and sludge.Process sintering helps to eliminate raw flux, which is the binder used to agglomerate the material,saving heating material,coke and increasing furnace productivity.Improvement and efficiency can be obtained by increasing the softening temperature and reducing the softening range of the melting zone, increasing the volume of the particle zone,and reducing the width of the cohesive zone.Lower silica content and higher hot metal temperature contribute to greater sulfur removal.