Mixed slag smelting reduction production and thermal refining method

Abstract

The invention discloses a mixed slag smelting reduction production and thermal refining method, and belongs to the field of non-blast furnace iron smelting and comprehensive utilization of resources. The method comprises the following steps: 1) an iron-contained material and a reducing agent are added in mixed slag of blast furnace slag and molten steel slag for heating to reach a molten state; and oxide gas is sprayed for iron smelting by smelting reduction to treat most iron-contained material; and 2) an iron component, a calcium silicon component and a phosphorus component in the mixed slag are separated and recovered according to a reaction device. After smelting reduction, the reduced slag can serve as a cement additive, a cement regulator, a cement clinker or a cement clinker with high production additional value, so that the method realizes efficient comprehensive utilization of the resources, and is a new smelting reduction iron making method. The method uses smelting reduction of the mixed slag for production of pig iron or steel and phosphorus-enriched phases and thermal refining, is short in reaction time, high in metal recovery rate, low in production cost, high in raw material adaptability, high in handling quantity, environment-friendly and high in economic benefit, and can effectively achieve the goal of efficient recycling of metallurgic resources and heat energy.

Description

technical field [0001] The invention belongs to the field of non-blast furnace ironmaking and resource comprehensive utilization, and in particular relates to a method for smelting reduction production and quenching and tempering treatment of mixed slag. Background technique [0002] In today's world, the production of blast furnace ironmaking is developing unprecedentedly, the scale of blast furnace is expanding continuously, the production consumption of blast furnace is decreasing, and the cost is lowered. It is still the main force of steel production. Production encountered huge challenges, the details are as follows: [0003] (1) Blast furnace has a long production process from raw material pretreatment, pelletizing plant, sintering plant, coking plant, and blast furnace ironmaking, and the total investment is very huge; [0004] (2) Strong dependence on metallurgical coke. With the increasingly scarce coking coal resources, the price of metallurgical coke is getting...

AI Technical Summary

Problems solved by technology

With the increasingly scarce coking coal resources, the price of metallurgical coke is getting higher and higher, but the abundant and cheap coking coal resources cannot be fully used in ironmaking production

The production of sinter, pellets and coking coal has brought serious environmental pollution, and the increasingly stringent environmental protection requirements have restricted blast furnace ironmaking technology;

[0005] (3) The reduction time of the traditional blast furnace is long. Although the enhanced smelting technology is adopted, the continuous improvement of productivity by relying on the enhanced smelting process is greatly limited;

[0006] (4) A large amount of flux is added;

[0007] (5) Difficult to deal with low-grade ore, polymetallic iron-containing paragenetic ore

Although steel slag can be utilized in the above ways, it is still subject to many limitations: (1) free CaO and MgO reduce the stability of steel slag volume; (2) higher content of iron oxides increases the difficulty of grinding; (3) steel slag When directly returning to the metallurgical process for reuse, phosphorus will gradually be enriched in iron, which limits the application of steel slag; (4) steel slag is easy to pulverize; (5) fluorine and heavy metals may be leached by rainwater to pollute the environment

At present, the utilization rate of steel slag is only 20%, resulting in a large accumulation of steel slag, which pollutes the environment and wastes resources

Images