Two-step steel slag treatment method using oxidation desulfurization and reduction dephosphorization

A technology of oxidation desulfurization and treatment method, which is applied in the field of iron and steel metallurgy, can solve the problems of reducing dephosphorization of steel slag, desulfurization ability, and adverse effects of molten steel composition, so as to improve the comprehensive utilization rate, avoid the increase of melting temperature, and reduce the cost of steelmaking Effect

Active Publication Date: 2019-08-30
钢研晟华科技股份有限公司
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  • Claims
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Problems solved by technology

[0004] In view of the above analysis, the embodiment of the present invention aims to provide a steel slag treatment method using two-step oxidation desulfurization and reduction dephosphorization to solve the

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  • Two-step steel slag treatment method using oxidation desulfurization and reduction dephosphorization

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Embodiment 1

[0029] This embodiment discloses a steel slag treatment method using two-step oxidation desulfurization and reduction dephosphorization methods, such as figure 1 shown, including the following steps:

[0030] Step S1. Oxidize and desulfurize the steel slag; pass Ar and O into the molten steel slag 2 The mixed gas, the SO obtained by oxidation 2 Overflowing and removing from the slag phase, the removal rate of S is 82-97%;

[0031] CaS+0 2 =CaO+SO 2

[0032] In step S1, the oxidizing atmosphere is Ar and O 2 The mixed gas, because it does not contain N 2 , to avoid the production of NOx, the resulting SO 2 It overflows and removes from the slag phase, making the removal rate of S as high as 82-97%.

[0033] Compared with the prior art, the present invention can completely solve the problem of removing sulfur and phosphorus in steel slag, greatly improve the recycling rate of steel slag, realize the full utilization of steel slag, S and P, reduce the cost of steelmaking,...

Embodiment 2

[0053] This embodiment adopts converter steel slag, wherein, TFe content is 18.2%, P 2 o 5 The content is 1.64%, the S content is 0.07%, and the dual natural alkalinity is 3.1. Put cold steel slag into a high-purity corundum crucible, heat it to 1650°C in a tubular resistance furnace and keep it warm for 30 minutes. After the steel slag is completely melted, an oxidizing atmosphere is provided through a thin corundum tube inserted from the top of the crucible. 2 The content is 10-35%, and the oxidation time is 15 minutes. After the reaction time is up, the crucible is taken out and rapidly cooled in the air. After crushing and grinding, the sulfur content and metal iron content of the slag are determined by a carbon-sulfur analyzer and chemical analysis.

[0054] The analysis results showed that the O in the atmosphere 2 The content is controlled at 10%, 15%, 20%, 30%, and 35%, and the removal rates of sulfur in steel slag are 54%, 82%, 91%, 95%, and 97%, respectively. It ...

Embodiment 3

[0058] This embodiment 3 and embodiment 1 adopt the same steel slag and adopt the same process flow for oxidation desulfurization treatment, the difference is that the oxygen partial pressure is controlled at 20%, and the oxidation time range is 5-20min. After the reaction time is reached, the The crucible was taken out and cooled rapidly in the air, and after crushing and grinding, the sulfur content of the slag was determined by a carbon-sulfur analyzer.

[0059] By analyzing Table 2, it can be seen that when the oxidative desulfurization time is 5 minutes, the sulfur removal rate is 47%, the sulfur removal rate exceeds 90% after the desulfurization time exceeds 10 minutes, and the sulfur removal rate does not increase significantly after the desulfurization time exceeds 15 minutes. 10 to 15 minutes.

[0060] Table 2 Changes of sulfur removal rate in steel slag with oxidation desulfurization time

[0061] Oxidative desulfurization time (min) 5 10～15 ＞15 Su...

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Abstract

The invention relates to a two-step steel slag treatment method using oxidation desulfurization and reduction dephosphorization, and belongs to the technical field of iron and steel metallurgy and resource utilization. According to the steel slag treatment method, the problem of S and P enrichment in the prior art of steel slag recycling is solved. The two-step steel slag treatment method using oxidation desulfurization and reduction dephosphorization comprises the following steps of 1, carrying out oxidation desulfurization of steel slags, specifically, a mixture of Ar and O2 is introduced into the molten steel slag, oxidized SO2 is removed from slag phase, and the removal rate of the S is 82%-97%; and 2, carrying out gas-based reduction dephosphorization of the desulfurized steel slag obtained in step 1, specifically, the reducing gas is a mixture of CO and CO2, the removal rate of the P is up to 80% or above, and reduced P2 is removed from the slag. According to the two-step steel slag treatment method using oxidation desulfurization and reduction dephosphorization, the problem of removing the S and the P from the steel slag is thoroughly solved, the recycling utilization ratioof the steel slag is greatly improved, and the full utilization of the steel slag, the S and the P is achieved, so that the cost of steel-making is reduced, the utilization values of the S and the P are improved, and the two-step steel slag treatment method has a broad application prospect.

Description

technical field [0001] The invention relates to the technical field of iron and steel metallurgy, in particular to a steel slag treatment method using two-step methods of oxidation desulfurization and reduction dephosphorization. Background technique [0002] China is a country with a large steel production capacity. On average, steel companies will produce about 120-150kg of steel slag for every 1 ton of steel produced. Steel slag has high alkalinity, and even after digestion treatment, it still contains a certain amount of free CaO and MgO, and the calcium silicate is in a metastable phase after quenching, and the structure stability is poor. It takes a long time to stabilize the process when it is directly used as backfill or paving material . At present, steel slag is obtained by magnetic separation to obtain slag steel, magnetic separation powder and tailing slag respectively. The slag steel is returned to the steelmaking furnace for recycling, the magnetic separation ...

Claims

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Application Information

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IPC IPC(8): C21B3/06
CPCC21B3/06Y02W30/50Y02P10/122Y02P10/20
Inventor 张俊周和敏徐洪军
Owner 钢研晟华科技股份有限公司
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