CN101863516B

CN101863516B - Method for recovering ferrite containing chromium and nickel in stainless steel pickling waste water sludge

Info

Publication number: CN101863516B
Application number: CN201010185146XA
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: 2013-12-11
Anticipated expiration: 2030-05-26
Also published as: CN101863516A

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

Contain the recovery method of chromium Ni ferrite in stainless steel pickling waste water sludge

Technical field

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

Technical background

Contain the heavy metals such as a large amount of iron, chromium, nickel in the mud produced in the stainless steel acid cleaning waste water treating processes, belong to the severe contamination material, if this pollutant is discharged 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 protection of the environment, for the local protection environment, sets up power-saving industrial, energy-efficient society is significant.

The processing present situation of the sludge containing heavy metal produced 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 the heavy metals such as a certain amount of Cr and Ni in 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 discharge to producing; promoted the development of environment protection, it is produced larger Social Ecology benefit.

At present, with the mud of stainless steel enterprises Wastewater Concentrated, recycle technique and the product for preparing the magnetic coupling Ferrite Material, have no the open source literature report.Realistic situation is: enterprises of producing stainless steel is considered technical obstacle, and the problems such as cost of economic benefit, so, produced waste water is not generally processed thoroughly, only preliminary treatment or just directly discharge of processing, cause that environmental pollution is serious, ecological damage, and heavy metal ion can have a strong impact on the human lives, must strictly control.

Summary of the invention

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

In the present invention, alleged ferrite refers to containing Fe 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:

In stainless steel pickling waste water sludge, containing the recovery method of chromium Ni ferrite, it is characterized in that comprising the steps:

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

In this step, need the water added in pulping process, water in can using.So-called middle water also is reuse water or recycle-water, is treated sewage recycling.Because in urban construction, water supply is called to " upper water ", sewage discharge is called " lower water ", so middle water is got its meaning between the two.Middle water has municipal sewage plant to focus on reuse, and the even independent house reuse voluntarily of community is also arranged.Community or house middle water among a small circle, generally only collect cleaner sewage, as bath water, swimming-pool water, kitchen drainage etc. are simply processed, as filtration, precipitation etc.Therefore the middle water of city centralized reuse need arrange separately pipe network, and investment is larger, but can saving water resource, and reduces quantity of wastewater effluent, therefore can reduce widely and supply water and the sewage disposal expense.The present invention also takes full advantage of the middle water use of pull an oar again after washing just, more environmental protection, saving running cost;

(2) acidleach process: the coarse raw materials stock pump after making beating is entered to sour bath, and add dense H ₂sO ₄or HCl adjusting pH value to 1.8～2.2, and soak 4～6 hours;

(3) filtration procedure: the coarse raw materials slurry that acid soak is crossed is stirred, and adds the cationic flocculant polyacrylamide, and filters, and obtains former slip; Be trapped the mud water and washed, the washing water after washing are got back in pulping process, with the mud in changing stock tank, mix and are pulled an oar, the filter mud discharge system after washing, recovery; Polyacrylamide, as flocculation agent, can be accelerated the sedimentation of the materials such as suspended substance in smart former slip, can be solion and fast as far as possible the separating of mud; In the present invention, the consumption of flocculation agent is generally that the material of coarse raw materials slurry is realized to effective sedimentation gets final product, those skilled in the art in the industry, can draw by the simple experiment of limited number of time its better consumption, 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 flocculation agent, other cationic flocculant also can play similarly, better effects, just in the used in amounts of using, will according to circumstances re-start calculative determination; Filter mud after washing can be made material of construction---fragment of brick, continues to recycle;

(4) alkalization process: after filtration obtains former slip, then to add mass content in former slip be 28% ammoniacal liquor or NaOH solution, regulates pH value to 4.0～4.5;

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

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

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

The chromium Ni ferrite that contains after above-mentioned processing has higher purity, generally can reach Fe ₂o ₃85% left and right, 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 washing; and washing water are got back to the pulping process of step (1); use as making beating water; and the consumption of washing water can be regulated according to the water consumption in pulping process, can guarantee like this realization of environmental protection.

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 on the existence conditions basis, carry out processing parameter realizes purpose of the present invention.

Embodiment

Below enforcement of the present invention is illustrated:

Embodiment 1

(1) pulping process: the waste water that enterprises of producing stainless steel is produced, mud are delivered to and are focused on treatment station, standing for some time, by sending into of the mud stock tank containing heavy metal chromium nickel produced, add water to be pulled an oar, through whipping device, fully stir, 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 making beating is entered to sour bath, simultaneously ready dense H ₂sO ₄add and regulate pH value to 2.0, and soak 4 hours; In the acidleach process, with whipping device, make acid solution fully contact, mix with the metal ion in the coarse raw materials slurry, reach the program of complete reaction, wait various ions and acid material to be combined into compound separately; In order to the operation such as can effectively separate in following step;

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

(4) alkalization process: after filtration obtains former slip, then add NaOH solution in former slip, regulate pH value to 4.3;

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

Stainless steel sludge after being processed 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%.There is good use value industrial.

Embodiment 2

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

(1) pulping process: the waste water that enterprises of producing stainless steel is produced, mud are delivered to and are focused on treatment station, standing for some time, by sending into of the mud stock tank containing heavy metal chromium nickel produced, add water to be pulled an oar, through whipping device, fully stir, 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 making beating is entered to sour bath, simultaneously ready dense H ₂sO ₄add and regulate pH value to 2.2, and soak 4 hours;

(4) alkalization process: after filtration obtains former slip, then add NaOH solution in former slip, regulate pH value to 4.2;

Stainless steel sludge after being processed 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 stainless steel waste water, it is characterized in that comprising the steps:

(1) pulping process: stainless steel acid cleaning waste water is processed, and sending into of the mud stock tank containing heavy metal chromium nickel of generation, add water to be pulled an oar, and wherein the mass ratio of mud and water is 1:4～5, and beating time is 1～2 hour;

(2) acidleach process: the coarse raw materials stock pump after making beating is entered to sour bath, and add HCl to regulate pH value to 1.8～2.2, and soak 4～6 hours;

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

2. according to the described recovery method of claim l, it is characterized in that the alkali of alkalization process in described step (4) is NaOH solution, regulate pH value to 4.3.