Method for reducing and recovering iron from steel slag and preparing auxiliary cementing material from secondary slag

A technology for cementing materials and recycling iron, applied in the direction of climate sustainability, improvement of process efficiency, sustainable waste treatment, etc., can solve the research of unmineral phase composition and gelation activity, no further research, equipment and process complex problems, to achieve effective large-scale comprehensive utilization, reduce the cost of landfill disposal, and reduce the effect of stacking sites

Active Publication Date: 2018-10-16
SOUTH CHINA UNIV OF TECH
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Problems solved by technology

The purpose of these two patented technologies is to reduce the iron in the molten steel slag and sinter the slag into cement clinker; the former adds iron ore and makes iron in a special reactor, and the equipment and process are more complicated. , the investment is large, and it is difficult to realize industrialization in my country's iron and steel plants; the latter only restores the original iron in the steel slag, and it is carried out in the slag discharge process, only a stirring process is added, but due to the high viscosity of the steel slag, it is very difficult to stir
Cang Daqiang from Beijing University of Science and Technology studied the addition of reducing agent and silicon oxide to prepare glass-ceramics from the secondary slag after reducing iron and extracting molten steel slag. It is not us

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  • Method for reducing and recovering iron from steel slag and preparing auxiliary cementing material from secondary slag

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preparation example Construction

[0039] In the embodiment, the preparation method of the present invention specifically includes the following steps:

[0040] (1) Composition analysis: conduct chemical composition analysis on steel slag, reducing agent and component adjustment materials respectively, and carry out batching design according to the analysis results. The principle is to select reducing agent and dosage according to the iron oxide content in steel slag, SiO 2 and Al 2 o 3 Content selection component adjustment material and dosage;

[0041] (2) Mixing batching: measure and batch steel slag, reducing agent and component adjustment material by mass percentage, and mix uniformly;

[0042] (3) Remelting: the mixture is remelted and calcined under a reducing atmosphere in a high-temperature furnace at a temperature of 1455-1495°C, and the calcining time is 31-60min;

[0043] (4) Water quenching: water quenching and cooling treatment of the calcined high-temperature molten slag;

[0044] (5) Separa...

Embodiment 1

[0047] Steel slag reduction recovery of iron and secondary slag to prepare auxiliary cementitious materials, the specific steps are as follows:

[0048] In terms of mass percentage, after mixing 65% of Baosteel steel slag, 5% of coal powder, 10% of industrial lime and 20% of sandstone evenly, remelting under a reducing atmosphere at 1495°C for 31 minutes, then quenching and cooling in water, and separating metallic iron, the two The secondary slag is dried and ground to obtain auxiliary gelling materials.

[0049] Among the raw materials used, Baosteel steel slag has a sieve percentage of 5.3% at 80 μm and a water content of 0.1%; coal powder has a sieve percentage of 0% at 80 μm and a water content of 0.2%; industrial lime has a sieve percentage of 0.9 at 80 μm %, the water content is 0.4%; the percentage of sandstone sieve at 80 μm is 9.8%, and the water content is 0.4%.

Embodiment 2

[0051] Steel slag reduction recovery of iron and secondary slag to prepare auxiliary cementitious materials, the specific steps are as follows:

[0052] In terms of mass percentage, after mixing 80% steel slag, 4% carbon powder, and 16% fly ash of Shaoguan Iron and Steel Co. After drying and grinding, the auxiliary gelling material is obtained.

[0053] Among the raw materials used, Baosteel steel slag has a sieve percentage of 5.1% at 80 μm and a water content of 0.1%; carbon powder has a sieve percentage of 0% at 80 μm and a water content of 0.3%; kaolin has a sieve percentage of 0.8% at 80 μm , with a moisture content of 0.1%.

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Abstract

The invention discloses a method for reducing and recovering iron from steel slag and preparing an auxiliary cementing material from secondary slag. The method comprises the following steps: uniformlymixing the converter steel slag, a reducing agent and a component adjusting material, performing melting back under the condition that high temperature forms a reducing atmosphere, performing water quenching cooling, separating the metal iron, drying the secondary slag, and performing grinding to obtain the auxiliary cementing material. The method disclosed by the invention can reduce and recoverthe iron in the steel slag by 80% or more; and the prepared auxiliary cementing material is similar to granulated blast furnace slag powder, technical indexes of the auxiliary cementing material meetrelevant requirements of a standard ''ground granulated blast furnace slag used for cement and concrete'' GB/T18046-2008 in China, and the auxiliary cementing material can be used as a cement mixed material and a concrete admixture. The method disclosed by the invention reduces Fe2O3 and FeO in the steel slag into the metal iron for recovery and utilization, changes chemical components of the steel slag to make the components similar to those of granulated blast furnace slag, improves gelling activity, and realizes overall, high-added-value, and more effective large-scale comprehensive utilization of the steel slag.

Description

technical field [0001] The invention relates to the technical field of converter steel slag disposal and application, in particular to a method for preparing auxiliary cementitious materials from steel slag reduction and recovery of iron and secondary slag. Background technique [0002] In recent years, my country's steel output has been ranking first in the world. In 2016, the output of crude steel reached 808 million tons; the discharge of converter steel slag (hereinafter referred to as steel slag) is about 15-20% of the steel output, and it is discharged at a rate of about 100 million tons every year. It belongs to bulk industrial solid waste. [0003] In fact, steel slag is an available resource. On the one hand, the main chemical composition of steel slag is similar to that of ordinary cementitious materials, containing SiO 2 、Al 2 o 3 , FeOx (the abbreviation of iron oxide), CaO, MgO, can be used in cement, concrete industry; 2 o 3 count), mainly Fe 2 o 3 It ex...

Claims

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Application Information

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IPC IPC(8): C04B7/147C04B18/14C21B11/00
CPCC04B7/147C04B18/142C21B11/00Y02W30/91Y02P10/20Y02P40/10
Inventor 殷素红杨旭郭辉高凡管海宇余其俊
Owner SOUTH CHINA UNIV OF TECH
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