Improvement method and special equipment for iron-containing slag

Abstract

The invention discloses a modification method of iron-containing slag and special equipment for the modification method. The method sequentially comprises the following steps: (1) spraying a mixture of a modifier and pulverized coal into a furnace hearth of a modification furnace so as to melt the modifier, and feeding the modifier in a high-temperature liquid state into the molten iron-containing slag; (2) adding a reducing agent into the slag and carrying out reduction on the slag so as to extract iron; (3) further spraying and blowing the mixture of the modifier and the pulverized coal into the furnace hearth of the modification furnace after the extraction of the iron and smelting the slag again. During the two modification processes, the mixture of the modifier and the pulverized coal is sprayed into the furnace hearth by virtue of two symmetric coal-fired vortex nozzles along a tangential direction of the furnace wall of the modification furnace, so that the modifier is molten in a heating manner and can be easily and evenly mixed with the molten slag; the modified slag can be directly used for preparing a high added-value product, so that the defects of the existing slag treatment and utilization mode which is simple, coarse, high in energy consumption and the like are avoided. The modification method disclosed by the invention has the characteristics of diversification of utilization mode, high utilization rate, good economic benefit, less environmental pollution and the like.

Description

technical field [0001] The invention relates to a method for utilizing metallurgical slag, in particular to a method for upgrading iron-containing slag produced in the metal smelting process and special equipment for realizing the method, belonging to the field of upgrading iron-containing slag. Background technique [0002] In the current smelting process of ferrous and non-ferrous metals, a large amount of high-temperature molten slag is produced. These slags are composed of slag-forming agents that need to be added deliberately for smelting or gangues mixed in ores. The main component is SiO 2 , CaO, MgO, Al 2 o 3 , FeO, Fe 2 o 3 and other oxides, because these oxides and the complex compounds they constitute have relatively high melting points, so the temperature of the slag discharged during the metallurgical process is generally higher than 1500 ° C, and the current treatment and utilization of these slags are almost all For cold slag, and the way of utilization is...

AI Technical Summary

Problems solved by technology

[0005] (1) The use of slag is aimed at the separate utilization of "slag" and "heat", which eventually leads to low utilization rate and poor economic benefits.

[0006] (2) In the process of slag utilization, because the composition of slag is difficult to meet the needs, part of it can be used by quenching and tempering in cold state, so it is necessary to crush and grind the slag, especially for slag with high hardness, the process efficiency Very low, high energy consumption, and the added value of the prepared products is generally low

Most of the slag can only be discarded due to the large difference between its composition and the composition requirements of the target material or the inability to achieve quenching and tempering in the cold state.

[0007] (3) Almost all the heat of the slag is wasted. Even if a certain amount of heat energy is recovered by a certain process at present, it still needs to pay a high cost

② Adding method of modifier: Since the viscosity of the molten slag is relatively high, and the viscosity will increase rapidly with the decrease of temperature, if the cold material is directly added to the molten slag, the slag will solidify rapidly, and then the It is very difficult and expensive to melt

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