CN101863516A

CN101863516A - Method for recovering ferrite containing chromium and nickel in stainless steel pickling waste water sludge

Info

Publication number: CN101863516A
Application number: CN201010185146A
Authority: CN
Inventors: 周才用; 纪忠民; 潘丽铭; 陈启松; 吕旭军
Original assignee: SONGYANG ENVIRONMENT MONITORING STATION
Current assignee: SONGYANG ENVIRONMENT MONITORING STATION
Priority date: 2010-05-26
Filing date: 2010-05-26
Publication date: 2010-10-20
Anticipated expiration: 2030-05-26
Also published as: CN101863516B

Abstract

The invention discloses a waste water treatment method, in particular to a treatment method of stainless steel waste water. The method comprises the following steps of: pulping; acid leaching: using concentrated H2SO4 or HCl to regulate the pH value; pulp screening; alkalization: using ammonia water or NaOH to regulate the pH value to 4.0-4.5; and filtering to obtain filter sludge i.e. a semi-finished ferrite product. The method has the advantages that heavy metal ions in waste water of stainless steel production can be effectively recovered, and the environment is profitably protected; the recovery cost is lower; and the equipment process is relatively not complicated. The method can be widely applied to stainless steel production enterprises.

Description

The recovery method that contains the chromium Ni ferrite in the stainless steel pickling waste water sludge

Technical field

The present invention relates to method for sludge treatment after a kind of wastewater treatment, specifically be meant a kind of treatment process of stainless steel pickling waste water sludge.

Technical background

Contain heavy metals such as a large amount of iron, chromium, nickel in the mud that produces in the stainless steel acid cleaning waste water treating processes, belong to the severe contamination material, if this pollutant discharges without processing, will be to the local ecological serious harm that produces; If but the recycling that can realize contained heavy metal will will promote the benign development of stainless steel industry in the protection environment, for the local protection environment, set up power-saving industrial, energy-efficient society is significant.

The processing present situation of the sludge containing heavy metal that produces according to the stainless steel acid cleaning waste water central treatment station and the requirement of developing a circular economy; according to the feature that contains a large amount of Fe and heavy metals such as a certain amount of Cr and Ni in the mud; eliminate the secondary pollution risk that may occur in the stainless steel waste water treating processes; stop the problem of environmental pollution of sludge containing heavy metal discharging to producing; promoted the development of environment protection, made it produce bigger social ecological benefits.

At present, recycle technology and the product for preparing magnetic complex ferrite material, do not see the open source literature report with the mud that the stainless steel enterprise wastewater focuses on.Realistic situation is: enterprises of producing stainless steel is considered technical obstacle, and the problems such as cost of economic benefit, so, the waste water that is produced is not generally handled completely, only be preliminary treatment or just directly discharging of processing, cause serious, the ecological damage of environmental pollution, and heavy metal ion can have a strong impact on the human lives, must strict control.

Summary of the invention

The present invention is directed to the present situation of present enterprises of producing stainless steel, handle the characteristic of back mud in conjunction with stainless steel acid cleaning waste water, develop a kind of in can comprehensive reutilization mud heavy metal ion, make it no longer to cause second environmental pollution.

Alleged ferrite is meant and contains Fe among the present invention ₂O ₃Metal oxide.Ferritic resistivity is more much bigger than metal, alloy magnetic material, and also has higher dielectric properties, so purposes is very extensive.

The present invention is achieved by following technical proposals:

The recovery method that contains the chromium Ni ferrite in the stainless steel pickling waste water sludge is characterized in that comprising the steps:

(1) pulping process: sending into of the mud stock tank that contains heavy metal chromium nickel with stainless steel waste water treatment plant produces, add entry and pull an oar, wherein the mass ratio of mud and water is 1: 4～5, beating time is about 1～2 hour; Making beating can realize mixing preferably, stirring action during this period, from economic angle, is favourable relatively; If time lengthening, the blended effect can be better, but economic benefit is not best, so select this time to pull an oar, can satisfy the demand of economic benefit simultaneously to play better technical effect completely;

In this step, need the water that adds, water in can using in the pulping process.Water also is reuse water or recycle-water in so-called, is that treated sewage recovery is used again.Because in the urban construction water supply is called " going up water ", sewage discharge is called " following water ", so middle water is got its meaning between the two.In water have the municipal sewage plant to focus on reuse, the reuse voluntarily of community even independent house is also arranged.Community or house middle water is among a small circle generally only collected cleaner sewage, simply handles as bath water, swimming-pool water, kitchen draining etc., as filtration, precipitation etc.The city concentrates the middle water of reuse that pipe network need be set separately, and therefore investment is bigger, but can the conserve water resource, and reduces quantity of wastewater effluent, therefore can reduce widely and supply water and the sewage disposal expense.The present invention has also made full use of uses of pulling an oar again of middle water after the washing, more environmental protection, saving running cost just;

(2) acidleach process: the coarse raw materials stock pump after will pulling an oar is gone into sour bath, and adds dense H ₂SO ₄Or HCl adjusting pH value to 1.8～2.2, and soaked 4～6 hours;

(3) filtration procedure: the coarse raw materials slurry that acid soak is crossed stirs, and adds the cationic flocculant polyacrylamide, and filters, and obtains former slip; Be trapped the mud water and wash, washing water after washing is got back in the pulping process, mixes and pulls an oar the filter mud discharge system after the washing, recovery with mud in changing stock tank; Polyacrylamide can be accelerated the sedimentation of the materials such as suspended substance in the smart former slip as flocculation agent, can be solion and fast as far as possible the separating of mud; In the present invention, the consumption of flocculation agent generally is that the material of coarse raw materials slurry is realized that effective sedimentation gets final product, those skilled in the art in the industry, can draw its preferable consumption by the simple experiment of limited number of time, and, even the consumption of flocculation agent is not very accurate, can not have influence on effective enforcement of the present invention yet; In addition, except polyacrylamide as the flocculation agent, other cationic flocculant also can play similarly, better effects, just will according to circumstances calculate definite again in the used in amounts of using; Filter mud after washing can be made material of construction---fragment of brick, continues to recycle;

(4) alkalization process: after process was filtered and obtained former slip, adding mass content again in former slip was 28% ammoniacal liquor or NaOH solution, regulated pH value to 4.0～4.5;

(5) filtration procedure: will filter the raw material after the alkalization, and can get filter mud, and be and contain the chromium Ni ferrite, the filtrate otherwise processed.

As preferably, the acid in the acidleach process in the above-mentioned recovery method step (2) is dense H ₂SO ₄, regulate pH value to 2.0.

As preferably, the alkali of alkalization process is NaOH solution in the above-mentioned recovery method step (4), regulates pH value to 4.3.

Have higher purity through the chromium Ni ferrite that contains after the above-mentioned processing, generally can reach Fe ₂O ₃About 85%, other major ingredient Cr ₂O ₃14%, NiO 1%.And in the screened stock process of step (3); can further be processed into the material of construction fragment of brick to the filter mud after the washing; and washing water are got back to the pulping process of step (1); usefulness as making beating water; and the consumption of washing water can be regulated according to the water consumption in the pulping process, can guarantee the realization of environmental protection like this.

Beneficial effect: the heavy metal ion of the present invention in can the efficient recovery stainless steel pickling waste water sludge; and advantageously protected environment; cost recovery is also lower, and apparatus and process is not very complicated relatively, and the change that can carry out processing parameter on the existence conditions basis realizes purpose of the present invention.

Embodiment

Below enforcement of the present invention is specified:

Embodiment 1

(1) pulping process: waste water, mud that enterprises of producing stainless steel produced delivered to focus on treatment station, leave standstill for some time, with sending into of the mud stock tank that contains heavy metal chromium nickel that produces, adding entry pulls an oar, fully stir through whipping device, wherein the mass ratio of mud and water is 1: 4, and beating time continues to be about 2 hours;

(2) acidleach process: the coarse raw materials stock pump after will pulling an oar is gone into sour bath, simultaneously ready dense H ₂SO ₄Add and regulate pH value to 2.0, and soaked 4 hours; In the acidleach process, with whipping device, make the metal ion in acid solution and the coarse raw materials slurry fully contact, mix, reach the program of complete reaction, materials such as various ions and acid are combined into separately compound; So that operation such as in following step, can effectively separate;

(3) filtration procedure: the coarse raw materials slurry that acid soak is crossed stirs, and adds the cationic flocculant polyacrylamide, and filters, and obtains former slip; Be trapped the mud water and wash, washing water after washing is got back in the pulping process, mixes and pulls an oar the filter mud discharge system after the washing, recovery with mud in changing stock tank;

(4) alkalization process: after process is filtered and obtained former slip, in former slip, add NaOH solution again, regulate pH value to 4.3;

(5) filtration procedure: will filter the former slip after the alkalization, and can get filter mud, and be and contain the chromium Ni ferrite, the filtrate otherwise processed.

Stainless steel sludge after handling according to above-mentioned steps has become operable Industrial products, i.e. ferrite semifinished product, and composition wherein is generally Fe ₂O ₃84%, other major ingredient Cr ₂O ₃14%, NiO 1%.Has good use value industrial.

Embodiment 2

According to according to example 1 step roughly the same, the waste water of enterprises of producing stainless steel, mud are handled:

(1) pulping process: waste water, mud that enterprises of producing stainless steel produced delivered to focus on treatment station, leave standstill for some time, with sending into of the mud stock tank that contains heavy metal chromium nickel that produces, adding entry pulls an oar, fully stir through whipping device, wherein the mass ratio of mud and water is 1: 5, and beating time continues to be about 1.5 hours;

(2) acidleach process: the coarse raw materials stock pump after will pulling an oar is gone into sour bath, simultaneously ready dense H ₂SO ₄Add and regulate pH value to 2.2, and soaked 4 hours;

(4) alkalization process: after process is filtered and obtained former slip, in former slip, add NaOH solution again, regulate pH value to 4.2;

Stainless steel sludge after handling according to above-mentioned steps has become operable Industrial products, i.e. ferrite semifinished product, and composition wherein is generally Fe ₂O ₃83%, other major ingredient Cr ₂O ₃13%, NiO 1.5%.

Claims

1. contain the recovery method of chromium Ni ferrite in the stainless steel waste water, it is characterized in that comprising the steps:

(1) pulping process: stainless steel acid cleaning waste water is handled, and sending into of the mud stock tank that contains heavy metal chromium nickel of generation adds entry and pulls an oar, and wherein the mass ratio of mud and water is 1: 4～5, and beating time is 1～2 hour;

(5) filtration procedure: the former slip after the alkalization is filtered, can get filter mud, be and contain the chromium Ni ferrite, the filtrate otherwise processed.

2. a kind of recovery method according to claim 1 is characterized in that the acid in the acidleach process in the described step (2) is dense H ₂SO ₄, regulate pH value to 2.0.

3. a kind of recovery method according to claim 1 is characterized in that the alkali of alkalization process in the described step (4) is NaOH solution, regulates pH value to 4.3.