Method for treating Cr-containing pickling sludge in slag bath

A treatment method and a technology for pickling sludge, applied in the field of metallurgical engineering, can solve the problems of Cr-containing pickling sludge pollution, difficult recovery of heavy metals, etc., and achieve the effects of source emission reduction, simple operation, and online recycling.

Inactive Publication Date: 2019-06-28
UNIV OF SCI & TECH BEIJING
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a method for treating Cr-containing pickling sludge in a slag bath to solve the problems of serious pollution and difficult recovery of heavy metals in Cr-containing pickling sludge

Method used

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  • Method for treating Cr-containing pickling sludge in slag bath
  • Method for treating Cr-containing pickling sludge in slag bath
  • Method for treating Cr-containing pickling sludge in slag bath

Examples

Experimental program
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Effect test

Embodiment 1

[0030] (1) Add reductant graphite powder and lime in chromium-containing pickling sludge and fully mix, wherein the mass percent of graphite powder, lime and pickling sludge is 22%: 7%: 71%;

[0031] (2) The mixed material is briquetted with a briquetting machine, dried at 110° C. for 5 hours, and prepared into Cr-containing acid-washed sludge pellets required for slag bath treatment;

[0032] (3) Take the AOD slag and mix it uniformly according to the mass ratio of molten slag, carbonaceous reducing agent and ferrosilicon powder at 98.9%: 0.85%: 0.25%, heat and melt at 1550°C, and keep it warm for 20 minutes to ensure a constant temperature. Throw the dried sludge pellets in (2) into the AOD slag for a slag bath reaction at 1550° C., the reaction time is 15 minutes, wherein the mass ratio of the sludge pellets to the AOD slag is 3%;

[0033] (4) After the slag is cooled, it is crushed, screened, and magnetically separated to separate metal particles.

Embodiment 2

[0035] (1) Add reductant graphite powder, additive and lime in chromium-containing pickling sludge and fully mix, wherein the mass percent of graphite powder, lime and pickling sludge is 18%: 8%: 74%;

[0036] (2) The mixed material is pressed into balls with a ball press machine, and dried at 120° C. for 3 hours to prepare Cr-containing acid-washed sludge pellets required for slag bath treatment;

[0037] (3) Take the AOD slag and heat and melt it at 1550°C, and keep it warm for 20 minutes to ensure a constant temperature. Throw the dried sludge pellets in (2) into the AOD slag and carry out the slag bath reaction at 1550°C. The reaction time is 20 Minutes, wherein the mass ratio of sludge pellets to AOD slag is 5%;

[0038] (4) After the slag is cooled, it is crushed, screened, and magnetically separated to separate the metal particles. image 3 It is the separated residue and metal particles.

Embodiment 3

[0040] (1) Add reductant graphite powder and lime in chromium-containing pickling sludge and fully mix, wherein the mass percent of graphite powder, lime and pickling sludge is 16%: 7%: 77%;

[0041] (2) Pressing the mixed materials with a briquetting machine and drying at 130° C. for 7 hours to prepare Cr-containing acid-washed sludge pellets required for slag bath treatment;

[0042] (3) Take converter slag and heat and melt it at 1600°C, keep it warm for 30 minutes to ensure a constant temperature, throw the dried sludge pellets in (2) into converter slag and carry out slag bath reaction at 1600°C, the reaction time is 15 minutes, wherein the mass ratio of sludge pellets to converter slag is 10%;

[0043] (4) After the slag is cooled, it is crushed, screened, and magnetically separated to separate metal particles.

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Abstract

The invention discloses a method for treating Cr-containing pickling sludge in a slag bath. The method comprises the following steps: 1, adding a reducing agent and lime into the Cr-containing pickling sludge, and fully mixing; 2, pressing the mixed materials into balls by a ball pressing machine, and drying the balls; 3, throwing the dried sludge balls into high-temperature metallurgical slag forreaction; and 4, and after cooling the molten slag, crushing, screening, performing magnetic separation to separate and recover metal particles. Under the process condition of the method, the high-temperature metallurgical slag is utilized to fully reduce and detoxify the Cr-containing pickling sludge by fixing most of sulfur elements in slag phase, secondary discharge is avoided in the process,valuable metal elements such as Cr/Fe are fully reduced to the metal phase, and the valuable metal elements are separated and recovered through the magnetic separation. The method is simple to operate, and can be operated in an original steelmaking process with no secondary discharge, so that on-line recycling and source emission reduction of the Cr-containing pickling sludge are achieved.

Description

technical field [0001] The invention relates to the technical field of metallurgical engineering, in particular to a method for treating Cr-containing pickling sludge in a slag bath. Background technique [0002] Pickling sludge, also known as pickling wastewater treatment sludge, is the solid waste produced by the treatment of pickling wastewater discharged from the metal surface treatment process. At present, the level of centralized treatment of pickling wastewater is very low. Most of the pickling wastewater is mainly neutralized and precipitated by cheap and easy-to-obtain lime. Due to the poor effect of lime on heavy metal precipitation, there is still a large amount of lime that does not participate in the reaction during the reaction process. It is wrapped by other flocs and sinks in the sludge, resulting in a large amount of sludge. At the same time, pickling sludge contains a large amount of nickel, chromium, iron and other heavy metals and residual acids that hav...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B7/00C22B34/32
CPCY02P10/20
Inventor 张延玲赵峥邢奕高金涛吴拓袁方
Owner UNIV OF SCI & TECH BEIJING
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