A method for improving the reduction disintegration rate of alkaline pellets

Abstract

The application discloses a method for improving the reduction disintegration rate of alkaline pellets, and performs drying, preheating and roasting, realizes that the compressive strength of the alkaline pellets is greater than or equal to 2500 N / P and ranges from 2100 N / P to 2200 N / P respectively by controlling the roasting temperature, and reasonably matches the basicity and the compressive strength of the alkaline pellets, so that when the compressive strength of the pellets is greater than or equal to 2500 N / P, the reduction disintegration rate of the pellets with different basicities ranging from 1.29 to 1.42 can be controlled within a better level of 10%, and when the compressive strength of the pellets ranges from 2100 N / P to 2200 N / P, the basicity is controlled within 1.29. The purpose of the application is to provide a method for improving the reduction disintegration rate of alkaline pellets and reducing the reduction disintegration rate of alkaline pellets of Baotou Steel.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of iron-making raw material briquetting, and in particular to a method for improving the reduction disintegration rate of alkaline pellets. BACKGROUND

[0002] With the implementation of the "double carbon" strategy in the steel industry, many enterprises have begun to gradually increase the proportion of pellet ore, which has lower energy consumption, to replace sinter ore, which has higher energy consumption. An important content of improving the proportion of pellet ore is to develop alkaline pellets with excellent metallurgical properties. Low-temperature reduction disintegration performance refers to the reduction disintegration performance of iron-containing furnace charge under low-temperature (400-600℃) reduction conditions, which is an index for measuring the performance of iron ore in the upper block zone of the blast furnace and has a great influence on blast furnace smelting. Research shows that for every 5% reduction in RDI+3.15 of iron-containing furnace charge, coke ratio increases by about 3 kg, and pig iron production decreases by 1.5-5%. In addition, the low-temperature reduction disintegration of iron ore has a great influence on furnace life, furnace wall and heat loss. Through systematic research, the present application clarifies the main factors affecting the reduction disintegration rate of alkaline pellets produced by Baotou Steel using Baiyunebo special ore, and proposes technical measures to reduce the reduction disintegration rate of alkaline pellets of Baotou Steel, which can provide technical support for improving the technical and economic indicators of Baotou Steel under the condition of high blast furnace pellet smelting. SUMMARY

[0003] The purpose of the present application is to provide a method for improving the reduction disintegration rate of alkaline pellets, and reducing the reduction disintegration rate of alkaline pellets of Baotou Steel.

[0004] To solve the above technical problems, the present application adopts the following technical solutions:

[0005] The present application is a method for improving the reduction disintegration rate of alkaline pellets, which performs drying, preheating and roasting, and controls the roasting temperature to achieve two kinds of alkaline pellet compressive strengths, i.e. ≥2500N / P and in the range of 2100-2200N / P, and reasonably matches the alkalinity and compressive strength of alkaline pellets. When the compressive strength of the pellet ore is ≥2500N / P, the reduction disintegration rate of different alkalinity 1.29-1.42 can be controlled within a good level of 10% or less, and when the compressive strength of the pellet ore is 2100-2200N / P, the alkalinity is controlled within 1.29.

[0006] Further, by controlling the limestone ratio, different alkalinity alkaline pellet green balls mainly using Baiyunebo ore as iron material are prepared using a disc pelletizer.

[0007] Further, the iron material structure used by the alkaline pellet green balls of different alkalinity is 75% Baiyunebo ore + 25% purchased iron concentrate, and the binder external ratio is 2.0%.

[0008] Further, the limestone ratio is respectively 2.8%, 3.2%, 3.6%, and the alkaline pellet green ball alkalinity is respectively 1.29, 1.36, 1.42.

[0009] Further, under the condition that the SiO2 content is unchanged, the lower the ball alkalinity, the lower the required compressive strength, and the higher the alkalinity, the higher the required compressive strength.

[0010] Compared with the prior art, the beneficial technical effects of the present application are:

[0011] The main factors affecting the reduction disintegration rate of the alkaline pellets produced by the Baiyunebo Mine applied by the Baotou Steel are clarified, and technical measures for reducing the reduction disintegration rate of the alkaline pellets of the Baotou Steel are proposed, which can provide technical support for improving the technical and economic indicators of the Baotou Steel under the high ball ratio smelting conditions. DETAILED DESCRIPTION

[0012] The specific embodiments of the present application will be further illustrated by the following examples, but the specific embodiments of the present application are not limited to the following examples.

[0013] The ingredient structure of the alkaline pellets of each example is shown in Table 1, the chemical composition of the alkaline pellets of each example is shown in Table 2, and the reduction disintegration rate determination results of the alkaline pellets of each example are shown in Table 3.

[0014] Table 1 Ingredient structure of alkaline pellets of each example

[0015]

[0016] Table 2 Indirect reduction degree, iron-containing charge softening performance, alkali leaching, and fluorine leaching scheme of each example

[0017] Example No. TFe / % FeO / % CaO / % SiO2 / % MgO / % Al203 / % R Example 1 61.94 0.5 3.43 2.66 1.25 0.62 1.29 Example 2 61.80 0.5 3.62 2.66 1.26 0.62 1.36 Example 3 61.67 0.5 3.8 2.67 1.26 0.61 1.42

[0018] As shown in Table 2, with the increase of the limestone ratio, the CaO content and alkalinity of the alkaline pellets increase, and the TFe decreases.

[0019] Table 3 Reduction disintegration rate determination results of alkaline pellets of each example

[0020]

[0021] From Table 3, it can be seen that the reduction disintegration index of the alkaline pellets is mainly related to the alkalinity of the alkaline pellets and the cold strength of the pellets. Based on the index control of the reduction disintegration, when the SiO2 content is unchanged, the lower the alkalinity of the pellets, the lower the required compressive strength, the higher the alkalinity, the higher the required compressive strength. By reasonably matching the alkalinity and the compressive strength of the alkaline pellets, the reduction disintegration rate of the alkaline pellets produced by using the Baiyunebo special ore can be controlled at a good level. When the compressive strength of the pellets is ≥2500 N / P, the reduction disintegration rate of the pellets with different alkalinity (1.29-1.42) can be controlled at a good level of less than 10%. When the compressive strength of the pellets is 2100-2200 N / P, it is suggested that the alkalinity be controlled to be less than 1.29.

[0022] The above-described embodiments are merely preferred modes of the present application and are not intended to limit the scope of the present application. Various modifications and improvements to the technical solutions of the present application made by those of ordinary skill in the art without departing from the design spirit of the present application shall fall within the scope of protection of the present application as defined by the claims.

Claims

1. A method for improving the reduction disintegration rate of alkaline pellets, characterized by: Drying, preheating, baking, by controlling the baking temperature, the compressive strength of the basic pellets is ≥2500N / P and range is 2100-2200N / P, the basicity and the compressive strength of the basic pellets are reasonably matched, when the compressive strength of the pellets is ≥2500N / P, the reduction disintegration rate of different basicity 1.29-1.42 can be controlled within 10% of a better level, when the compressive strength of the pellets is 2100-2200N / P, the basicity is controlled within 1.29; By controlling the limestone ratio, using a disc balling machine, different basicity of basic pellets green balls are prepared mainly with Baiyunebo ore; The iron material structure of the basic pellets green balls with different basicity is 75% Baiyunebo ore + 25% purchased iron concentrate, and the binder external ratio is 2.0%.

2. The method for improving the reduction disintegration rate of basic pellets according to claim 1, characterized by: The limestone ratio is 2.8%, 3.2%, 3.6% respectively, and the basicity of the basic pellets green balls is 1.29, 1.36, 1.42 respectively.

3. The method of improving the reduction disintegration rate of basic pellets according to claim 1, characterized by: Under the condition that the SiO2 content is unchanged, the lower the basicity of the pellets, the lower the required compressive strength, and the higher the basicity, the higher the required compressive strength.

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