The main process of blast furnace ironmaking
The system composition of the blast furnace ironmaking process: raw material system, feeding system, furnace roof system, furnace body system, crude gas and gas cleaning system, tuyere platform and tapping house system, slag processing system, hot blast stove system, pulverized coal preparation and Blowing system, auxiliary system (cast iron machine room, iron ladle repair room and mud mill room).
1. Raw material system
The main task of the raw material system. Responsible for the storage, batching, screening and weighing of various ore and coke required for blast furnace smelting, and deliver the ore and coke to the feed truck and the main belt. The raw material system is mainly divided into two parts: ore tank and coke tank
2. Feeding system
The function of the feeding system is to transport various raw materials and fuels stored in the ore tank and coke tank to the top charging equipment of the blast furnace. The feeding methods of the blast furnace mainly include the inclined bridge feeder and the belt conveyor.
3. Furnace top charging equipment
The function of the furnace top charging equipment is to reasonably distribute the charge in the blast furnace according to the furnace conditions. There are two types of furnace top charging equipment, bell top charging equipment and bellless top charging equipment. Most small blast furnaces below 750m3 use bell top charging equipment, and most large and medium blast furnaces above 750m3 use bell-free top charging equipment.
Four, furnace system
The furnace body system is the heart of the entire blast furnace ironmaking system. All other systems ultimately serve the furnace body system. Almost all chemical reactions in the blast furnace ironmaking system are completed in the furnace body. The quality of the furnace body system directly determines the whole Whether the blast furnace ironmaking system is successful or not, the service life of the first blast furnace is actually the generation life of the furnace body system, so the furnace body system is the most important system for the entire blast furnace ironmaking system.
5. Crude gas system
The crude gas system consists of a gas outlet pipe, an ascending pipe, a descending pipe, a relief valve, a dust collector, ash discharge and ash removal and humidification devices.
The blast furnace gas produced by the blast furnace contains a large amount of dust, and the dust in the blast furnace gas must be removed before it can be used as purified gas.
6. Tuyere Platform and Casting Yard System
(1) Tuyere platform. The function of the tuyere platform is to provide a place to replace the tuyere, observe the furnace condition and overhaul.
The tuyere platform is generally a steel structure, but can also be a concrete structure or a combination of steel and concrete structures. A layer of refractory bricks is generally laid on the surface of the tuyere platform, and the gap between the platform and the furnace shell is covered with a steel cover plate.
(2) Casting ground. The role of the cast house is to deal with molten iron and slag from the blast furnace.
1) The main equipment of the casting yard, the crane in front of the furnace, the mud gun, the opening machine, and the slag blocking machine. Modern large blast furnaces are generally equipped with swing nozzles and uncovering machines. Hot metal storage equipment mainly includes hot metal tanks and tank cars, mixed iron cars and tank cars.
2) There are two types of casting yard, rectangular casting yard and circular casting yard.
Seven, slag processing system
The role of the slag treatment system is to convert the liquid slag produced in the blast furnace into dry slag and water slag. Dry slag is generally used as construction aggregate, and some dry slag has some special uses. Slag can be sold to cement plants as raw materials for cement production.
8. Hot blast stove system
The role of hot blast stove in the ironmaking process. The cold air sent by the blower is heated into high-temperature hot air and then sent to the blast furnace, which can save a lot of coke. Therefore, the hot-blast furnace is an important energy-saving and cost-reducing facility in the ironmaking process.
9. Coal preparation and injection system
The function of the system. The coal is ground into fine powder and the moisture in the coal is dried. The dried coal is transported to the tuyere of the blast furnace, and then sprayed into the blast furnace from the tuyere to replace part of the coke. Blast furnace coal injection is an important measure to replace coke with coal, save coke resources, reduce the production cost of pig iron, and reduce environmental pollution.
10. Auxiliary system of auxiliary facilities
(1) Cast iron machine room.
(2) Mill room.
