Waste acid recovery treatment method for sludge generated in steel wire rope plant

Abstract

The invention discloses a waste acid recovery treatment method for sludge generated in a steel wire rope plant. Steel wire rope acid washing waste acid is used for leaching metal irons of iron, lead and zinc in the steel wire rope sludge; sludge residue is conveyed to a hazardous waste treatment center to be treated; iron powder is used for reducing ferric ions into ferrous ions; through sulfide precipitation, lead and zinc ions are precipitated; the generated lead and zinc precipitates are cleaned and dried; the material can be used as a lead and zinc melting raw material due to the lead andzinc abundance; the purified ferrous chloride solution can be sold as production raw materials of polymeric ferric chloride flocculant; hydrogen sulfide gas generated in the reaction process and unorganized emission hydrogen sulfide gas are treated by two-stages of filling material adsorption towers and an active carbon deodorization device, the discharge is performed after the contaminant discharge standard is met; the generated sulfide is reused in a coagulation precipitation system. The method provided by the invention solves the problems that the sludge and waste acid generated in the steel wire rope production process of high toxicity, great harm, high yield, difficult processing and secondary pollution generation and the like.

Description

technical field

[0001] The invention relates to a method for recycling and treating sludge waste acid, in particular to a method for recycling and treating sludge waste acid produced in a steel wire rope factory. Background technique

[0002] Steel wire rope waste acid is the pickling waste liquid produced in the production process of steel wire rope, which generally contains 3-11% HCl and a large amount of Fe 2+ , Pb 2+ , Zn 2+ ion. Because of its high acid concentration and strong corrosiveness, it is included in the national hazardous waste list (HW34 waste acid). Currently widely used treatment methods include (1) acid-base neutralization method, but the consumption of chemicals is large, and a large amount of heavy metal sludge will be generated, resulting in secondary pollution; (2) high-temperature roasting method, recovering HCl and iron red, but The processing cost of this process is high, and the iron red produced contains a certain amount of lead and zinc ions...

Examples

Embodiment 1

[0042] The whole process is tested by treating 500kg wire rope sludge:

[0043] The composition of steel wire rope sludge is as follows: moisture content 61.9%, iron content 13.7%, lead content 0.4%, zinc content 2.6%; steel wire rope pickling waste acid composition is as follows, HCl content 9.5%, iron content 8.2%, lead content 3.7g / L , Zinc content 2.0g / L.

[0044] will be 2m 3 Add waste acid from steel wire rope pickling to the heavy metal sludge extraction reactor, add 500kg of steel wire rope sludge, and fully stir for 2 hours; the supernatant enters the reduction reactor, add 40kg of reduced iron powder, fully stir for 2 hours, and settle for 1 hour; The clear liquid enters the pH adjustment tank, and gradually adds about 200L of 20% sodium hydroxide solution dropwise to adjust the pH to 2.4; the adjusted pH solution enters the coagulation system, and gradually adds 120L of 20% sodium sulfide solution dropwise, Stir fully for 30 minutes; the supernatant is filtered to...

Embodiment 2

[0047] The whole process is tested by treating 500kg wire rope sludge:

[0048]The composition of steel wire rope sludge is as follows: moisture content 65.4%, iron content 12.3%, lead content 0.25%, zinc content 2.8%; steel wire rope pickling waste acid composition is as follows, HCl content 9.5%, iron content 8.2%, lead content 3.7g / L , Zinc content 2.0g / L.

[0049] will be 2m 3 Put the waste acid from steel wire rope pickling into the heavy metal sludge extraction reactor, add 500kg of steel wire rope sludge, and fully stir for 2 hours; the supernatant enters the reduction reactor, add 35kg of reduced iron powder, fully stir for 2 hours, and settle for 1 hour; The clear liquid enters the pH adjustment tank, and gradually adds 160L of 20% sodium hydroxide solution dropwise to adjust the pH to 2.0; the adjusted pH solution enters the coagulation system, and gradually adds 120L of 20% sodium sulfide solution dropwise to fully Stir for 30 minutes; the supernatant is filtered ...

Embodiment 3

[0052] To process 60g of steel wire rope sludge, a small laboratory experiment was carried out on the whole process:

[0053] The composition of steel wire rope sludge is as follows: moisture content 62.3%, iron content 13.5%, lead content 0.4%, zinc content 1.4%; steel wire rope pickling waste acid composition is as follows, HCl content 9.5%, iron content 8.2%, lead content 3.7g / L , Zinc content 2.0g / L.

[0054] Add 300mL of steel wire rope pickling waste acid into the heavy metal sludge extraction reactor, add 60g of steel wire rope sludge, and stir for 2 hours; after filtering, the supernatant enters the reduction reactor, add 5g of reduced iron powder, and stir for 2 hours; filter Finally, in the coagulation and sedimentation device, gradually add about 15mL of 20% sodium hydroxide solution dropwise, adjust the pH to 2.4, then gradually add 15mL of 20% sodium sulfide solution dropwise, and fully stir for 30 minutes; after filtration The filter residue was washed and dried...

technical field

[0001] The invention relates to a method for recycling and treating sludge waste acid, in particular to a method for recycling and treating sludge waste acid produced in a steel wire rope factory. Background technique

[0002] Steel wire rope waste acid is the pickling waste liquid produced in the production process of steel wire rope, which generally contains 3-11% HCl and a large amount of Fe 2+ , Pb 2+ , Zn 2+ ion. Because of its high acid concentration and strong corrosiveness, it is included in the national hazardous waste list (HW34 waste acid). Currently widely used treatment methods include (1) acid-base neutralization method, but the consumption of chemicals is large, and a large amount of heavy metal sludge will be generated, resulting in secondary pollution; (2) high-temperature roasting method, recovering HCl and iron red, but The processing cost of this process is high, and the iron red produced contains a certain amount of lead and zinc ions...

Examples

Embodiment 1

[0042] The whole process is tested by treating 500kg wire rope sludge:

[0043] The composition of steel wire rope sludge is as follows: moisture content 61.9%, iron content 13.7%, lead content 0.4%, zinc content 2.6%; steel wire rope pickling waste acid composition is as follows, HCl content 9.5%, iron content 8.2%, lead content 3.7g / L , Zinc content 2.0g / L.

[0044] will be 2m 3 Add waste acid from steel wire rope pickling to the heavy metal sludge extraction reactor, add 500kg of steel wire rope sludge, and fully stir for 2 hours; the supernatant enters the reduction reactor, add 40kg of reduced iron powder, fully stir for 2 hours, and settle for 1 hour; The clear liquid enters the pH adjustment tank, and gradually adds about 200L of 20% sodium hydroxide solution dropwise to adjust the pH to 2.4; the adjusted pH solution enters the coagulation system, and gradually adds 120L of 20% sodium sulfide solution dropwise, Stir fully for 30 minutes; the supernatant is filtered to...

Embodiment 2

[0047] The whole process is tested by treating 500kg wire rope sludge:

[0048]The composition of steel wire rope sludge is as follows: moisture content 65.4%, iron content 12.3%, lead content 0.25%, zinc content 2.8%; steel wire rope pickling waste acid composition is as follows, HCl content 9.5%, iron content 8.2%, lead content 3.7g / L , Zinc content 2.0g / L.

[0049] will be 2m 3 Put the waste acid from steel wire rope pickling into the heavy metal sludge extraction reactor, add 500kg of steel wire rope sludge, and fully stir for 2 hours; the supernatant enters the reduction reactor, add 35kg of reduced iron powder, fully stir for 2 hours, and settle for 1 hour; The clear liquid enters the pH adjustment tank, and gradually adds 160L of 20% sodium hydroxide solution dropwise to adjust the pH to 2.0; the adjusted pH solution enters the coagulation system, and gradually adds 120L of 20% sodium sulfide solution dropwise to fully Stir for 30 minutes; the supernatant is filtered ...

Embodiment 3

[0052] To process 60g of steel wire rope sludge, a small laboratory experiment was carried out on the whole process:

[0053] The composition of steel wire rope sludge is as follows: moisture content 62.3%, iron content 13.5%, lead content 0.4%, zinc content 1.4%; steel wire rope pickling waste acid composition is as follows, HCl content 9.5%, iron content 8.2%, lead content 3.7g / L , Zinc content 2.0g / L.

[0054] Add 300mL of steel wire rope pickling waste acid into the heavy metal sludge extraction reactor, add 60g of steel wire rope sludge, and stir for 2 hours; after filtering, the supernatant enters the reduction reactor, add 5g of reduced iron powder, and stir for 2 hours; filter Finally, in the coagulation and sedimentation device, gradually add about 15mL of 20% sodium hydroxide solution dropwise, adjust the pH to 2.4, then gradually add 15mL of 20% sodium sulfide solution dropwise, and fully stir for 30 minutes; after filtration The filter residue was washed and dried...

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