CN100430521C

CN100430521C - Purification treatment process of waste liquor of hydrochloric acid

Info

Publication number: CN100430521C
Application number: CNB2006100189678A
Authority: CN
Inventors: 赵金标; 秦健; 赵海
Original assignee: Wisdri Engineering and Research Incorporation Ltd
Current assignee: Wisdri Engineering and Research Incorporation Ltd
Priority date: 2006-04-28
Filing date: 2006-04-28
Publication date: 2008-11-05
Anticipated expiration: 2026-04-28
Also published as: CN1843965A

Abstract

The present invention relates to a process for purifying waste acid. The purification processing technique of waste liquor of hydrochloric acid is characterized in that the technique comprises the procedures that 1, ammonium hydroxide is put into a sludge reactor and is mixed and stirred with return sludge, and then a mixture A is obtained; 2, the mixture A is input into a neutralization reaction tank and is mixed and stirred with hydrochloric acid waste liquid under aeration conditions, and then a mixture B is obtained; 3, a coagulant aid and the mixture B are input into a reaction clarification tank, 30 to 60 mg/l coagulant aid is added in each liter combine solution B. The reaction clarification tank is arranged in a settling tank, and the mixed liquid in the reaction clarification tank after being flocculated subsequently enters the settling tank for precipitating; purified hydrochloric acid waste liquid is in the upper part of the settling tank and enters an acid liquid collection tank via a pipe, sludge on the bottom of the settling tank is sent into a sludge reactor via a return sludge flow pipe and a return sludge flow pump. The present invention increases the purification effects of the waste acid liquid of hydrochloric acid.

Description

Purification treatment process of waste liquor of hydrochloric acid

Technical field

The invention belongs to iron and steel and chemical field, be specifically related to a kind of technology that spent acid purified of hydrochloric acid pickling waste liquor regenerating unit that is applicable to for improving that the brown iron oxide quality done.

Background technology

Iron and steel or chemical enterprise hydrochloric acid pickling waste liquor, generally adopt spray roasting that spent acid is regenerated, spent acid is atomisation in stoving oven, under 550-650 ℃ hot environment, iron protochloride is decomposed into hydrogen chloride gas and brown iron oxide, hydrogen chloride gas reclaims and is used for the pickling unit through absorb forming regenerating acid, and brown iron oxide is recycled, and is mainly used in coating and magneticsubstance industry, the powder metallurgy industry is used as raw material.For satisfying the requirement of magneticsubstance to the iron powder quality, in spent acid sprays into stoving oven before, need purify spent acid solution, to satisfy the requirement of producing the high-purity mangesium oxide iron powder.As shown in Figure 1, traditional process using is reacted spent acid heating and input cheet scrap, remove free hydrochloric acid, after cooling off, add ammoniacal liquor then, and produce ironic hydroxide through the aeration oxidation, drop into coagulant aids again, form bigger flco,, be purified through the spent acid of post precipitation with the impurities such as colloid silicon in spent acid absorption, spray into stoving oven, can produce highly purified brown iron oxide.

Summary of the invention

The object of the present invention is to provide a kind of purification treatment process of waste liquor of hydrochloric acid of good purification.

To achieve these goals, technical scheme of the present invention is: purification treatment process of waste liquor of hydrochloric acid, it is characterized in that it comprises the steps: 1), with ammoniacal liquor drop in the sewage sludge reactor with returned sluge mixing stirring after mixture A, the dosage of ammoniacal liquor is that 4-4.5 is a benchmark with the pH value that control adds the mixture B in the ammoniacal liquor post neutralization retort; 2), mixture A is input in the neutralization reaction jar, under aeration condition, mix with hydrochloride waste stir mixture B, shared separately mixture A of mixture A, hydrochloride waste and hydrochloride waste weight percent are: mixture A 5-10%, hydrochloride waste 90-95%; 3), coagulant aids and mixture B are input in the reaction clarifying tank, the coagulant aids dosage of every liter of mixture B is 30-60mg; The reaction clarifying tank is arranged in the settling bath, and reaction is provided with opening at the bottom of the clarifying tank, in the reaction clarifying tank after flocculating mixing liquid take advantage of a situation to enter in the settling bath and precipitate; Settling bath top is the hydrochloride waste after purifying, and the hydrochloride waste after the purification is entered in the acid solution holding tank by pipeline, and the settling bath bottom is a mud, and settling bath bottom mud is sent in the sewage sludge reactor by mud return line, sludge reflux pump.

Add FeCl in the neutralization reaction jar ₃, the FeCl of every liter of hydrochloride waste ₃Dosage is 0.3-0.5g.

1), because coagulant aids is to be added to the reaction clarifying tank that is positioned at settling bath (or claim settling tank) center the present invention adopts aforesaid method to have following characteristics:, mixing liquid is taken advantage of a situation to enter in the settling bath and is precipitated after flocculating, flocculating effect is good, and the flco that flocculation is good directly enters the settling region, therefore be easy to precipitation, sedimentation effect improves, and has improved the decontamination effect improving of acid solution.And traditional flocculation jar be located at settling tank from outside, liquid after the flocculation needs enter the settling region through pipeline, flco is destroyed in pipeline, enters settling region postprecipitation poor effect.2) mud is back to sewage sludge reactor, and ammoniacal liquor then is added in the sewage sludge reactor, and ammoniacal liquor is adsorbed onto the returned sluge carrier surface, and mud and ammonia water mixture enter in the neutralization reaction jar then, the FeCl in the spent acid ₂And add into FeCl ₃Ammoniacal liquor reaction with being adsorbed onto the returned sluge carrier surface generates Fe (OH) ₂And Fe (OH) ₃Be adsorbed in the sludge carrier surface, at this Fe (OH) ₂Be oxidized to Fe (OH) ₃The flco particle diameter that the more traditional ammoniacal liquor of flco that forms directly is added to the retort generation is big and closely knit, easier precipitation and dehydration, in addition, a large amount of mud reflux increased with acid solution in the contacting and collision opportunity of colloidalmaterial, improved the colloidal adsorptive power, improved the decontamination effect improving of hydrochloride waste acid solution.

3), add an amount of FeCl ₃And the ammoniacal liquor reaction generates more Fe (OH) ₃, to improve colloidalmaterial, as SiO to containing in the spent acid ₂Deng, improved decontamination effect improving.

4), make the unit area loading rate of settling tank improve the expense of to reduce investment outlay.

3), the water ratio of mud further reduces, and also reduced the consumption of acid solution, improved acid recovering rate.

Description of drawings

Fig. 1 is traditional purification treatment process of waste liquor of hydrochloric acid figure

Fig. 2 is purification treatment process of waste liquor of hydrochloric acid figure of the present invention

Embodiment

The present invention is described further below in conjunction with accompanying drawing.

As shown in Figure 2, purification treatment process of waste liquor of hydrochloric acid, it comprises the steps: 1), with ammoniacal liquor drop in the sewage sludge reactor with returned sluge mixing stirring after mixture A, the dosage of ammoniacal liquor is that 4-4.5 is a benchmark with the pH value that control adds the mixture B in the ammoniacal liquor post neutralization retort.2), mixture A is input in the neutralization reaction jar, under aeration condition, mix stirring, add FeCl in the neutralization reaction jar with hydrochloride waste ₃, getting mixture B, shared separately mixture A of mixture A, hydrochloride waste and hydrochloride waste weight percent are: mixture A 5-10%, hydrochloride waste 90-95%; The FeCl of every liter of hydrochloride waste ₃Dosage is 0.3-0.5g.3), coagulant aids (or claim flocculation agent, adopt existing the use, as polyacrylamide) and mixture B be input to react in the clarifying tank, the coagulant aids dosage of every liter of mixture B is 30-60mg; The reaction clarifying tank is arranged in the settling bath, and reaction is provided with opening 4 at the bottom of the clarifying tank, in the reaction clarifying tank after flocculating mixing liquid take advantage of a situation to enter in the settling bath and precipitate; Settling bath top is the hydrochloride waste after purifying, hydrochloride waste after the purification is entered in the acid solution holding tank by pipeline, the settling bath bottom is a mud, settling bath bottom mud is sent in the sewage sludge reactor by mud return line 3, sludge reflux pump 2, mud reverse flow valve 1 is set on the mud return line, and returned sluge stops 1-5min in sewage sludge reactor.Settling bath bottom mud is sent into sludge dewatering system by the sludge dewatering pipe, and the sludge dewatering valve is set on the sludge dewatering pipe, and the waste liquid after the sludge dewatering system dehydration is by in the pipeline input reaction clarifying tank.

Claims

1. purification treatment process of waste liquor of hydrochloric acid, it is characterized in that it comprises the steps: 1), with ammoniacal liquor drop in the sewage sludge reactor with returned sluge mixing stirring after mixture A, the dosage of ammoniacal liquor is that 4-4.5 is a benchmark with the pH value that control adds the mixture B in the ammoniacal liquor post neutralization retort; 2), mixture A is input in the neutralization reaction jar, under aeration condition, mix with hydrochloride waste stir mixture B, shared separately mixture A of mixture A, hydrochloride waste and hydrochloride waste weight percent are: mixture A 5-10%, hydrochloride waste 90-95%; 3), coagulant aids and mixture B are input in the reaction clarifying tank, the coagulant aids dosage of every liter of mixture B is 30-60mg; The reaction clarifying tank is arranged in the settling bath, and reaction is provided with opening at the bottom of the clarifying tank, in the reaction clarifying tank after flocculating mixing liquid take advantage of a situation to enter in the settling bath and precipitate; Settling bath top is the hydrochloride waste after purifying, and the hydrochloride waste after the purification is entered in the acid solution holding tank by pipeline, and the settling bath bottom is a mud, and settling bath bottom mud is sent in the sewage sludge reactor by mud return line, sludge reflux pump.

2. purification treatment process of waste liquor of hydrochloric acid according to claim 1 is characterized in that: add FeCl in the neutralization reaction jar ₃, the FeCl of every liter of hydrochloride waste ₃Dosage is 0.3-0.5g.