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An electric furnace smelting stainless steel method for controlling chromium pollution in steel slag

An electric furnace smelting and stainless steel technology, applied in the direction of electric furnaces, furnaces, furnace types, etc., can solve problems such as environmental pollution, achieve the effect of improving the state of occurrence and reducing the pollution of chromium

Active Publication Date: 2022-05-13
WISDRI ENG & RES INC LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the invention is to overcome the existence of undissolved CaO in the existing electric furnace stainless steel smelting process, and produce CaCr 2 o 4 And the MgO phase containing chromium, which brings the problem of environmental pollution when the steel slag is hot-simmered

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] The stainless steel slag produced during the traditional stainless steel smelting process using lime as the raw material for slagging was taken, and the composition and microscopic morphology of the stainless steel slag were analyzed. CaCr was precipitated around 2 o 4 and chromium-containing MgO. According to the industry standard HJ / T 299-2007 "Toxic leaching method for solid waste leaching", take 50g of the slag sample and add it to the mixed solution of sulfuric acid and nitric acid with a pH value of 3.2 (the mass ratio of sulfuric acid and nitric acid is 2:1). Ratio is set as 10:1, shakes 18h under the condition of 30rpm in the overturning shaker, after leaching test finishes, carry out vacuum filtration to obtain filtrate, adopt ICP-OES to measure the total chromium concentration in leachate; Measurement result It shows that the dissolution of chromium in stainless steel slag reaches 5.32mg / L under the condition of using traditional lime as slagging raw materia...

Embodiment 2

[0027] The stainless steel slag produced by using lime as the slagging raw material in the process of smelting stainless steel in an electric furnace was taken, and the composition and microscopic appearance of the stainless steel slag were analyzed. The analysis shows that there is a certain amount of free CaO in the composition of the stainless steel slag. According to the industry standard HJ / T 299-2007 "Toxic leaching method for solid waste leaching", take 50g of the slag sample and add it to the mixed solution of sulfuric acid and nitric acid with a pH value of 3.2 (the mass ratio of sulfuric acid and nitric acid is 2:1). Ratio is set to 10:1, vibrate 18h under the condition of 30rpm in the overturning shaker, after the leaching experiment finishes, carry out vacuum filtration to obtain filtrate, adopt ICP-OES to measure the total chromium concentration in the leaching solution, the measurement result It shows that the amount of chromium dissolved in stainless steel slag r...

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Abstract

The invention provides an electric furnace smelting stainless steel method for controlling chromium pollution in steel slag, comprising the following steps: adding slagging raw materials into the smelting furnace in batches during the stainless steel smelting process, so that the slagging raw materials are dissolved in the steel slag; wherein, the first Lime and dolomite are used as raw materials for one batch of slagging, and dolomite and low melting point composite slag are used as raw materials for subsequent batches of slagging. This method significantly eliminates the existence of free CaO in the slag, and eliminates the chromium-containing CaCr precipitated at the boundary of CaO 2 o 4 and MgO phase, while the Al in the composite slag 2 o 3 It can also play the role of modifying stainless steel slag, improving the occurrence state of chromium in stainless steel slag, realizing the enrichment of chromium to the stable spinel phase, thereby reducing the pollution of chromium in electric furnace steel slag produced in the stainless steel smelting process at multiple latitudes.

Description

technical field [0001] The invention belongs to the technical field of electric furnace steelmaking, and in particular relates to an electric furnace smelting stainless steel method for controlling chromium pollution in steel slag. Background technique [0002] With the rapid development of my country's economy, the output of stainless steel continues to increase, and at the same time, a large amount of stainless steel slag from electric furnaces is produced. As of 2018, the output of stainless steel in my country has exceeded 30 million tons, a year-on-year increase of 12%. Based on the calculation that 0.25 tons of stainless steel slag will be produced for every ton of steel produced, about 7.5 million tons of electric furnace stainless steel slag can be produced every year, and it is on the rise. . In the stainless steel smelting process, a certain amount of lime needs to be added to the slag to achieve the purpose of dephosphorization and desulfurization of molten steel....

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C21C5/54C21C7/076
CPCC21C5/005C21C7/076C21C7/0087Y02P10/20
Inventor 操龙虎徐永斌陈洪智李伟坚成剑明
Owner WISDRI ENG & RES INC LTD
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