Method for reducing coal consumption by comprehensively and circularly utilizing waste heat of Webster furnace

Abstract

The invention relates to a method for reducing coal consumption by cyclic utilization of waste heat of a Webster furnace. According to the method, heat generated by the exothermic reaction process is collected for the endothermic reaction process by means of the reaction principle of smelting zinc oxide by a direct method in production of the Webster furnace, so that heat is recycled, the use level of coal required for the endothermic process is reduced, the fuel coal and reducing coal required in the reaction process are saved, and the power consumption can be reduced by 30%. From the oxidizing chamber of the Webster furnace, cooling and settling processes of zinc oxide smoke are performed, and heat exchanged in the processes can be used for drying agglomerates. The agglomerates are prepared from mixtures of zinc-containing materials, coal and the like which are pressed to pellets through a ball press machine. Before the agglomerates enter into the hearth to be smelted, the agglomerates can be aired till the moisture is lower than 8%. By using the method, the drying time of the agglomerates can be accelerated, and the production efficiency is improved by over 10%.

Description

technical field [0001] The invention belongs to the field of non-ferrous metal smelting, and in particular relates to a method for comprehensively recycling waste heat of a Webster furnace in a production process to reduce coal consumption. Background technique : [0002] The theoretical basis of the direct method of zinc oxide production is that zinc oxide can be reduced by the reducing agent carbon monoxide, the reduction process absorbs heat, and the zinc vapor obtained from the reduction is oxidized by oxygen in the air and releases a large amount of heat. Zinc oxide products were collected in the room. [0003] At present, the direct method of zinc oxide is smelted in a reverberatory furnace called a Webster furnace. The structural diagram of the Webster furnace is shown in the attached image 3 . Zinc oxide production is based on lump ore as raw material and anthracite lump coal as fuel (bottom coal) to provide heat and maintain temperature during the smelting proce...

AI Technical Summary

Problems solved by technology

[0013] There are some obvious disadvantages in the production method mentioned above. In order to continuously maintain the heat required for the smelting process, the amount of fuel coal (bottom coal) and The amount of pulverized coal is greatly excessive, a large amount of coal is wasted, and new impurities are introduced into the coal, which affects product quality

Even so, the air blasted into the bottom of the furnace in the cold winter is cold air, which is difficult to heat up in the early stage of smelting, and in the later stage of smelting, the more the air is blown, the lower the furnace temperature will be, which will affect the normal progress of smelting, and then affect the next smelting cycle, forming a vicious circle

[0014]There is also a big disadvantage, that is, the natural drying of the lump ore takes a long time and takes up a lot of space, especially at sub-zero temperatures, the lump ore freezes into Once the hard lumps are thrown into the furnace, the ice will melt and the agglomerates will disperse, which will affect the smelting process. The zinc in the dispersed agglomerates will be difficult to restore, which will affect the recovery rate. At the same time, the dispersed materials will enter the flue gas and affect the product quality. Affect the recovery rate according to the current method only to add more reduced coal

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