Method for preparing chromel alloy by stainless steel pickling sludge

A technology of pickling sludge and nickel-chromium alloy, which is applied in the field of metal smelting and can solve the problems of underutilization, environmental pollution, waste of resources, etc.

Active Publication Date: 2014-01-22
TAIZHOU YONGXING ALLOY MATERIAL TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] In the field of stainless steel processing, sludge treated with waste acid is often produced, which often contains toxic heavy metals and waste acid, such as Cr 6+ It will be a highly toxic metal. If it is directly discharged, it will not only seriously pollute the environment, but also cause a waste of resources. Therefore, how to effectively recycle stainless

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] Various indicators of pickling sludge in a stainless steel plant: the main chemical components of stainless steel pickling sludge are: Ni1.2%, Cr 5%, and waste acid H 2 SO 4 , HCl, HNO 3 and HF.

[0017] The method for preparing nickel-chromium alloys from stainless steel pickling sludge comprises the following steps: adding calcium hydroxide to the stainless steel pickling sludge to adjust the pH to 6.5 to obtain neutral sludge; adding the neutral sludge to a rotary kiln at 250°C Carry out drying to obtain the dry basis; add the dry basis to the ball making machine, and at the same time add coke and starch for ball making to obtain mixed granules; put the mixed granules into the rotary kiln for reduction smelting, and control the smelting temperature at 1250 ° C, and add NCP at the same time -2 The initial reduction reaction of additives is carried out for 1 hour to obtain the metal state ball; the metal state ball is hot-packed into the plasma electric furnace to me...

Embodiment 2

[0020] Various indicators of pickling sludge in a stainless steel plant: the main chemical components of stainless steel pickling sludge are: Ni3%, Cr 6%, and waste acid H 2 SO 4 , HCl, HNO 3 and HF.

[0021] The method for preparing nickel-chromium alloys from stainless steel pickling sludge comprises the following steps: adding calcium hydroxide to the stainless steel pickling sludge to adjust the pH to 7.5 to obtain neutral sludge; adding the neutral sludge to a rotary kiln at 300°C Carry out drying to obtain the dry basis; add the dry basis to the ball making machine, and at the same time add coke and starch to make balls to obtain mixed granules; put the mixed granules into the rotary kiln for reduction smelting, and control the smelting temperature at 1400 ° C, and add sulfuric acid at the same time Sodium was initially reduced for 2 hours to obtain a metal state ball; the metal state ball was hot-packed into a plasma electric furnace to melt and smelt the nickel-chrom...

Embodiment 3

[0024] Various indicators of pickling sludge in a stainless steel plant: the main chemical components of stainless steel pickling sludge are: Ni2.1%, Cr 5.5%, and waste acid H 2 SO 4 , HCl, HNO 3 and HF.

[0025] The method for preparing a nickel-chromium alloy from stainless steel pickling sludge comprises the following steps: adding calcium hydroxide to the stainless steel pickling sludge to adjust the pH to 7 to obtain neutral sludge; adding the neutral sludge to a rotary kiln at 275°C Carry out drying to obtain the dry basis; add the dry basis to the ball making machine, and at the same time add coke and starch to make balls to obtain mixed granules; put the mixed granules into the rotary kiln for reduction smelting, and control the smelting temperature at 1350 ° C, and add NCP at the same time -2 Additives undergo initial reduction reaction for 1.5 hours to obtain metal state balls; heat pack the metal state balls into a plasma electric furnace to melt and smelt the nic...

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PUM

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Abstract

The invention provides a method for preparing chromel alloy by stainless steel pickling sludge. The method comprises the steps as follows: an alkali liquor is added into the stainless steel pickling sludge, pH is adjusted to be in a range from 6.5 to 7.5, and neutral sludge is obtained; the neutral sludge is added into a rotary kiln for drying to obtain a dry basis; the dry basis is added into a ball forming machine, and coke and starch are simultaneously added for ball forming to obtain mixed particles; the mixed particles are added into the rotary kiln for reduction smelting, the smelting temperature is simultaneously controlled in a range from 1,250 DEG C to 1,400 DEG C, and an additive is simultaneously added for an early reduction reaction for 1-2 hours to obtain metallic balls; and a hot bag containing the metallic balls is placed into an electric plasma furnace for melting and smelting to obtain the chromel alloy. With the adoption of the method, waste is changed into valuable materials, the stainless steel pickling sludge which can pollute the environment is neutralized, nickel-chromium elements are reduced to obtain the chromel alloy for metal smelting; and the chromel alloy with high recovery rate and high content is obtained through addition of an NCP additive and sodium sulfate.

Description

technical field [0001] The invention belongs to the field of metal smelting, and in particular relates to a method for preparing nickel-chromium alloys from stainless steel pickling sludge. Background technique [0002] In the field of stainless steel processing, sludge treated with waste acid is often produced, which often contains toxic heavy metals and waste acid, such as Cr 6+ It will be a highly toxic metal. If it is directly discharged, it will not only seriously pollute the environment, but also cause a waste of resources. Therefore, how to effectively recycle stainless steel pickling sludge has become a major trend in the research of scholars today. There are also many related researches. Most of the methods for treating stainless steel pickling sludge are aimed at making it harmless, and using related means to convert harmful metals into harmless products and then discharge them, which does not make full use of the value of its metals. Contents of the inventio...

Claims

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Application Information

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IPC IPC(8): C22B7/00C22C1/02
CPCY02P10/20
Inventor 宗义正
Owner TAIZHOU YONGXING ALLOY MATERIAL TECH
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