Control Of Alkali Metal Hazard In Blast Furnace Of Jiugang

From 1950 onwards,China's metallurgical researchers began to realize that blast furnmace brick-lined tumor,blast furnace smelting may be caused by the concentration of alkali metal in the blast furnace,therefore,the older generation of steelman through the blast furnace anatomy from different heightsampling analysis and research to obtain the distribution of alkali metal and the distribution of furnace material in the blast furnace and the inevitable relationship between them,that is,the concentration of alkali metal in the blast furnace,the impact of alkali metal on the physical properties of the material,chemical production.Compared with the current blast furnace smelting technology in the last century,the structure of furnace materials has changed greatly,and the hazards of alkali metal are highlighted by the use of blast furnaces with high alkali metal content in raw materials.The wine-steel furnace material is composed of acidic ball and high alkalinity sintering ore and block ore,of which high alkalinity sintering ore accounts for about 75 percent,the raw material of the firing plant is almost self-produced concentrate,while the wine-steel self-produced concentrate comes from the Mirror Iron Mountain mine,the mine is characterized by:K2O,Na2O,ZnO content is relatively high at 0.301%;The metal load of ferro-alkali metal in the wine-steel blast furnace was 6 to 8 kg/t,the zinc load was 1.5 to 1.8 kg/t,and the sulfur load was in the range of 6 to 7 kg/t.In the national steel industry,the wine and steel furnaces in alkali metal,sulfur is high.Therefore,it has brought great harm to the production of wine-steel blast furnaces.Therefore,to understand the concentration status,reaction and distribution of alkali metal in the wine-steel blast furnace,to find out the best alkali-draining measures,so that the damage of alkali metal to the blast furnace to a minimum or even zero.If the alkali load in the blast furnace is relatively high,it will bring a series of adverse effects to the blast furnace,such as high alkalinity sintering ore low temperature reduction powdering rate increases,acidic ball ore produces abnormal expansion,so that the powder rate of clinker increases the intensity of the decrease,The metallurgical coking and melting reaction has a catalytic effect and the alkali metal vaporization is deposited or penetrated into the brick lining as the gas flow rises,thereby reducing the particle size and strength of coke;Clinker and coke are different degrees of powdering phenomenon,gas flow window is blocked by small furnace powder,resulting in the blast furnace parts in varying degrees of resistance loss increased,further deterioration of the blast furnace column breathability,the pressure difference gradient in the furnace higher than normal level,smelting strength decreased,and eventually may cause the blast furnace road conditions are not smooth,The gasability of the furnace material and the gas flow movement are extremely unsuitable,the blast furnace material stops to drop more than 1 to 2 batch time,the blast furnace material difficult to carry out abnormal phenomenon and even the case of tumor.Based on the above-mentioned hazards,the article in the combination of the actual production of the no.1 blast furnace of the gable steel ironworks,through a large number of literature collection and summary,the use of on-site production data for phased theoretical analysis,calculation and combined with other iron works around the world to control alkali harm experience measures,And after the wine and steel blast furnace in the furnace control alkali and slag drainage problem put forward a reasonable measures to prevent and control the alkali damage of blast furnace,mainly:(1)to reduce the raw materials into the furnace,coke,blowing coal powder in the air mouth alkali metal;(2)reduce the ash in coke,improve the strength,enhance the resistance to alkali metal damage;(3)the use of high performance of refractory materials to resist the erosion of alkali metal;(4)Establish a system of tracking and analysis of changes in alkali metals,and regularly implement the application of alkali;(5)the alkalinity of the slag should be reduced appropriately,and the amount of slag should be increased appropriately,taking into account other indicators;(6)Maintain a reasonable thermal system in order to effectively reduce the recycling of alkali metals in blast furnaces;(7)The wind area is reduced and the kinetic energy is increased;...