The system and method for nickelous carbonate are extracted in a kind of waste mixed acid from acid-washing stainless steel
Technical field
The present invention relates to extract nickelous carbonate in field of waste water treatment more particularly to a kind of waste mixed acid from acid-washing stainless steel to be
System and its method, the system and method is particularly suitable for the waste mixed acid that is generated after acid-washing stainless steel.
Background technology
At present, during nickel chromium stainless steel is processed, removing the oxide layer of stainless steel surface needs to carry out pickling processes.
Pickling is divided into sulfuric acid washing, two stages of the nitration mixture pickling prepared by nitric acid and hydrofluoric acid complete.Sulfuric acid washing stage master
If removing iron oxide and chromium oxide, nitration mixture pickling stages are further removal chromium oxide and removal nickel oxide.The metal of wash-off
Into acid solution, when the amount of metal ion for entering acid solution reaches certain value, pickle failure is discharged into spent acid.Meanwhile per single order
After section pickling, the residual acid of stainless steel surface need to be washed away with water, flushing water use after into outer row acid wash water.
Nickel content is 0.8g/l, waste mixed acid nickel content 5g/l, acid wash water nickel content 0.2g/ in the Waste Sulfuric Acid of pickling discharge
l.China is the poor country of nickel resources, is of great significance with recycling nickel in the nickeliferous three wastes.The nickel master that acid-washing stainless steel comes out
It is enriched in waste mixed acid, waste mixed acid becomes the resource of valuable recycling nickel.
The processing method of the pickle liquor of existing stainless steel includes:
Method 1:Waste Sulfuric Acid, waste mixed acid, acid wash water are mixed, reacted with lime with sour, the metal ion in acid solution into
Hydroxide precipitates, and sulfate radical obtains nickeliferous slag into calcium fluoride precipitate into calcium sulfate precipitation, fluorine ion after solid-liquor separation.
Nickeliferous slag or supplying sintering feed are individually sintered blocking, then are smelted into blast furnace or other smelting furnaces, obtain the nickel pig iron, realize nickel money
It recycles in source.
This method recycle nickel, there are the defects of one of be:Spent acid content is 20%, the acid content 2% in wash water, 10 times
Spent acid is mixed into, while need to be neutralized with lime to alkalescence (pH value 8.5) in the wash water of spent acid, increases lime consumption.Lime band
Calcium sulfate, calcirm-fluoride that the impurity that enters and reaction generate etc., which enters, neutralizes slag, dilutes nickel grade, and the nickel in slag only has 1%, this
The low-grade nickeliferous material of kind recycles nickel with sintering-smelting process, economically obviously unreasonable.
This method recycle nickel, there are the defects of second is that:Calcium sulfate in slag decomposites sulfur dioxide in sintering,
In the presence of steam, acid mist corrosion agglomerating plant is formed, reduces the service life of equipment.The sulphur in sinter is remained in, is being smelted
When enter molten iron, also increase steel-making desulfurization burden.
This method recycles nickel, there are the defects of three be:Large quantities of lime is consumed during neutralization, increase calcium in waste water from
Sub- content increases waste water subsequent processing into can be with the burden of recycle-water.
Method 2:Application No. is a kind of 201210277047.3 Chinese patent application " times of nickel in waste acid from stainless steel acid washing
Receiving processing method ", the method that nickel is recycled in the slave stainless steel acid-washing waste liquid of proposition.
This method mixes Waste Sulfuric Acid with waste mixed acid, and the pH value of mix acid liquor first is transferred to 4-4.5 with lime, make iron,
Chromium precipitates, and nickel is stayed in acid solution, takes filtrate that pH value is transferred to 9-10 with lime again after solid-liquor separation, and the filtrate of solid-liquor separation is
The nickel mud of extraction, drainage discharge after PH is adjusted to 8 with sulfuric acid again.
This method is substantially similar to method 1, equally mixes Waste Sulfuric Acid with waste mixed acid, is equally neutralized using lime
Agent.It is a difference in that using precipitating twice, precipitation removes de-iron, chromium for the first time, and second of precipitation obtains nickel mud, twice intermediate processing
Advantageous effect be receive the grade of nickel mud is increased to 7%, shortcoming does not have the defects of pointed by solution 1.Meanwhile it uses
Sulfuric acid discharged after turning down the pH value of drainage, also wasted sulfuric acid resource.
Method 3:Waste mixed acid is handled with spray roasting, incidentally recycles nickel.
This method also recycles nickel, chromium, iron while nitric acid and hydrofluoric acid is recycled.Obtained nickeliferous, chromium iron oxide
Powder purity is higher, but the grade of nickel is low, and only 3%, it is worth as nickel raw material not high.
Compared with method 1 and method 2, although this method can recycle the utility in waste mixed acid, there are equipment
The problem of investment is big, and operating cost is high, and treatment scale is limited.The reason is that the roaster used is the condition in high temperature and deep-etching
Lower work, high to the harsh cost of antiseptic property requirement of equipment, other common consumption spare part short lifes, replacement frequently makes equipment
It is low to start rate.In addition, insoluble particles content has higher requirements in the waste mixed acid being atomized to entering roaster, otherwise easily cause roasting
Stove knot wall and shut down, the exceeded waste mixed acid of particle content of pickling line discharge cannot be into roaster, can only be at neutralization method
Reason, which limits the application scales of this method.
In view of all there are problems that in the above method, need to develop in scientific research and practice it is a kind of can be high in waste mixed acid
Efficient extract nickel, the nickel raw material that extracts again can be with producing the liquid energy reuse generated after dilval, extraction at low cost
In the waste mixed acid for neutralizing the acid wash water that acid-washing stainless steel generates, the good acid-washing stainless steel of overall economic efficiency processing system and
Processing method.
Invention content
The present invention provides the system and method that nickelous carbonate is extracted from acid-washing stainless steel waste mixed acid, and the system and method is special
It is not suitable for the waste mixed acid generated after acid-washing stainless steel, the waste water that extraction after generates high for the extraction efficiency of wherein nickel element
It can be back to and neutralize the acid wash water that acid-washing stainless steel generates.
The present invention is achieved by the following technical solutions:
The system that nickelous carbonate is extracted in a kind of waste mixed acid from acid-washing stainless steel, including the first neutralization reactor, the first separation
Equipment, the second neutralization reactor, the second separation equipment;
Wherein:
First neutralization reactor, water outlet are connect with first separation equipment;For receiving waste mixed acid and neutralization
Agent, and the first neutralization reaction is carried out, obtain the first neutralization reaction mixed liquor;
First separation equipment, water inlet are connect with first neutralization reactor, and water outlet is neutralized with described second
Reactor connects;For the first neutralization reaction mixed liquor to be carried out the first separating treatment, the first separating filtrate is respectively obtained
With the first separation filter residue;
Second neutralization reactor, water inlet are connect with first separation equipment, water outlet and the second separation equipment
Connection;For receiving first separating filtrate and neutralizer, and the second neutralization reaction is carried out, obtain the second neutralization reaction mixing
Liquid;
Second separation equipment, water inlet are connect with second neutralization reactor;It is anti-for described second to be neutralized
Mixed liquor is answered to carry out the second separating treatment, respectively obtains the second separation supernatant and the second separation concentrated solution.
As preferred embodiment, which further includes:
First filtering equipment, feeding mouth are connect with second separation equipment;For by second separation concentrated solution into
The first press filtration of row is reacted, and obtains the first pressing filtering liquid and the first filtrate.
As preferred embodiment, which further includes:
Causticization reactor, water inlet connect with second separation equipment or are also connect with first filtering equipment, gone out
The mouth of a river is connect with third neutralization reactor;For receiving the second separation supernatant and caustic, respectively obtain on causticization liquid
Clear liquid and caustic precipitation.
As preferred embodiment, which further includes:
Third neutralization reactor, water inlet are connect with the causticization reactor;For receive the causticization liquid supernatant and
Acid wash water, and third neutralization reaction is carried out, obtain third neutralization reaction mixed liquor.
As preferred embodiment, which further includes:
Second filtering equipment, feeding mouth are connect with the causticization reactor, and water outlet connects with the third neutralization reactor
It connects;For the caustic precipitation to be carried out the second press filtration reaction, obtain the second pressing filtering liquid and the second filtrate, second filtrate into
Enter the third neutralization reactor.
A kind of method that nickelous carbonate is extracted in waste mixed acid from acid-washing stainless steel, includes the following steps:
First neutralization reaction step:It is 4.0-6.0 that neutralizer to pH value is added in into waste mixed acid, carries out first and neutralizes instead
It should;0.5-2h is stood again, obtains the first neutralization reaction mixed liquor;
First separating step:The first neutralization reaction mixed liquor is subjected to the first separating treatment, respectively obtains first point
From filtrate and the first separation filter residue;
Second neutralization reaction step:It is 8.0-10.0 to add in neutralizer to pH value to first separating filtrate, carries out the
Two neutralization reactions obtain the second neutralization reaction mixed liquor;
Second separating step:The second neutralization reaction mixed liquor is subjected to the second separating treatment, respectively obtains second point
From supernatant and the second separation concentrated solution.
As preferred embodiment, this method further includes:
First press filtration processing is carried out to second separation concentrated solution, obtains the first pressing filtering liquid and the first filtrate.
Preferably, the method further includes:
Causticizing reaction step:It is 11.0-14.0 to add in caustic to pH value into the described second separation supernatant, is carried out severe
Change reaction, obtain caustic precipitation and causticization supernatant;
Preferably, the method further includes:
Third neutralization reaction step:It is mixed together with acid wash water by the causticization supernatant or with the second pressing filtering liquid, into
Row third neutralization reaction obtains third neutralization reaction mixed liquor.
Preferably, the method further includes:
Second press filtration processing is carried out to the caustic precipitation, obtains second pressing filtering liquid and the second filtrate;Again by described in
Second pressing filtering liquid and the causticization supernatant converge, into the third time neutralization reaction step.
As preferred embodiment, the neutralizer is sodium carbonate liquor, and the caustic is calcium hydroxide suspension;
Preferably, the mass percent concentration of the sodium carbonate liquor is 10% to saturation, more preferably 25%-40%,
The mass percent concentration of the calcium hydroxide suspension is 30%-90%, more preferably 40-50%.
As preferred embodiment, this method further includes:
First filtrate is subjected to solid phase reduction processing, obtains dilval.
As preferred embodiment, the temperature of solid phase reduction processing is 1000-1250 DEG C, more preferably 1150
℃;Preferably, the reduction treatment with carbon ratio be 10-20%, more preferably 15%.
Compared with prior art, the present invention has the advantages that:
1st, system and method for the invention can expeditiously extract nickel, extraction by neutralization reaction twice in waste mixed acid
The nickel raw material gone out again can be with producing dilval at low cost.
2nd, the present invention can also by causticizing reaction and third time neutralization reaction, the liquid of generation can be back to neutralize it is stainless
The acid wash water that steel pickling generates.
2nd, each step parameter of system and method for the invention, each equipment are rationally set, and are acted synergistically, and are further increased
The strong treatment effect of waste mixed acid and nickelous carbonate recovering effect:
The first separation filter residue of the present invention contains iron, chromium, but not containing sulfate, and metal is recycled using sintering-smelting
When avoid corrosion to agglomerating plant, do not increase the desulfurization burden of smelting;
The sinking speed of nickel precipitation in the second separation concentrated solution of the present invention is fast, and reaction liquid energy is made to continuously enter sedimentation
Slot, supernatant continuously filter out subsider, and solid-liquor separation speed is fast, and treating capacity is big, can work continuously;
The nickel grade of the second isolated nickelous carbonate of the present invention can reach 30-50%, can use the side of direct-reduction
Method obtains dilval, and the metal nickel content of dilval can reach 40-85%;Dilval is reduced directly by nickelous carbonate to avoid
Existing feed throughput is big during other low nickel raw material smelting ferronickels, and alloy is low containing rate, and energy consumption is high, pollutant emission pair
Various drawbacks that environment adversely affects.
3rd, the liquid discharged after causticizing reaction of the invention is the sodium hydroxide solution of low concentration, can be used for neutralizing acidity
Wash water realizes the treatment of wastes with processes of wastes against one another, has environmental benefit.
Description of the drawings
Fig. 1 is the schematic diagram of the waste mixed acid processing system of acid-washing stainless steel provided by the invention.
Wherein, the reference numerals are as follows shown in figure:
1st, the first neutralization reaction tank, 2, horizontal centrifuge, the 3, second neutralization reaction tank, 4, precipitation separating tank, 5, causticization it is anti-
Answer tank, the 6, first plate and frame filter press, the 7, second plate and frame filter press, 8, third neutralization reaction tank.
Specific embodiment
In a first aspect, the present invention provides the system that nickelous carbonate is extracted from acid-washing stainless steel waste mixed acid.In order to more preferable geographical
The solution present invention, below in conjunction with the accompanying drawings, the technical solution and its effect further illustrated the present invention using specific embodiment.
As shown in Figure 1, the waste mixed acid processing system of acid-washing stainless steel includes:Sequentially connected first neutralization reactor ---
First neutralization reaction tank 1, the first separation equipment --- horizontal centrifuge 2, the second neutralization reactor --- second neutralization reaction tank
3rd, the second separation equipment --- precipitation separating tank 4, causticization reactor --- causticizing reaction tank 5, the first filtering equipment --- first
Plate and frame filter press 6, the second filtering equipment --- the second plate and frame filter press 7, third neutralization reactor --- third neutralization reaction tank
8.More than component is illustrated one by one below.
First neutralization reaction tank 1, water outlet are connect with above-mentioned horizontal centrifuge 2.Waste mixed acid is collected in the first neutralization reaction
In tank 1, neutralizer (preferably sodium carbonate liquor) is slowly added in thereto while stirring, until Ph values is 4.0-6.0 and stand
For a period of time, the first neutralization reaction is carried out on this condition, obtains the first neutralization reaction mixed liquor.In the first neutralization reaction,
Iron ion generation ferric hydroxide precipitate in waste mixed acid, chromium ion generation chromium hydroxide precipitation are included in above-mentioned first and neutralize
In reaction mixture.
Horizontal centrifuge 2, water inlet are connect with above-mentioned first neutralization reaction tank 1, water outlet and above-mentioned second neutralization reaction
Tank 3 connects.Above-mentioned first neutralization reaction mixed liquor carries out the first separating treatment by the horizontal centrifuge 2, respectively obtains first
Separating filtrate and the first separation filter residue;First separating filtrate then flows into the second neutralization reaction tank 3;The first separation filter residue master
To include above-mentioned ferric hydroxide precipitate and chromium ion generation chromium hydroxide precipitation, the side that above two precipitation passes through sintering-smelting
Formula carries out subsequent metal recovery work.
Second neutralization reaction tank 3, water inlet are connect with above-mentioned horizontal centrifuge 2, and water outlet connects with above-mentioned precipitation separating tank 4
It connects.Above-mentioned first separating filtrate adds in neutralizer (preferably sodium carbonate while agitating in the second neutralization reaction tank 3
Solution), until Ph values are 8.0-10.0, the second neutralization reaction is carried out on this condition, obtains the second neutralization reaction mixed liquor.
In two neutralization reactions, the nickel ion generation nickelous carbonate in the first separating filtrate.
Precipitate separating tank 4, water inlet connect with above-mentioned second neutralization reaction tank 3, water outlet respectively with causticizing reaction tank 5,
First plate and frame filter press 6 connects.Above-mentioned second neutralization reaction mixed liquor carries out the second separating treatment, divides by precipitating separating tank 4
The second separation supernatant and the second separation concentrated solution are not obtained.The second separation supernatant preferably then flows into above-mentioned causticizing reaction
Tank 5 can also individually store otherwise processed;The second separation concentrated solution positioned at 4 bottom of precipitation separating tank flows into the first sheet frame pressure
Filter 6 carries out the first press filtration processing, obtains the first pressing filtering liquid and the first filtrate.First filtrate mainly includes nickelous carbonate, passes through
The mode of direct-reduction prepares dilval;First pressing filtering liquid, can also be single it is also preferred that then flow into above-mentioned causticizing reaction tank 5
Solely storage otherwise processed.
As preferred embodiment, above-mentioned second separation supernatant and the first pressing filtering liquid continue in following equipment
Reason:
Causticizing reaction tank 5, water inlet are connect respectively with precipitation separating tank 4, the first plate and frame filter press 6, water outlet respectively with
Third neutralization reaction tank 8, the second plate and frame filter press 7 connect.Above-mentioned second separation supernatant, the first pressing filtering liquid are in causticizing reaction tank
In 5, caustic (calcium hydroxide suspension (i.e. milk of lime) preferably) is added in, until Ph values are 11.0-14.0, on this condition
Causticizing reaction is carried out, respectively obtains causticization liquid supernatant and caustic precipitation.The causticization supernatant then flows into third neutralization reaction
Tank 8, the raw material as other production technologies carry out other processing;The caustic precipitation enters the second plate and frame filter press 7 and carries out second
Press filtration is handled, and obtains the second pressing filtering liquid and the second filtrate.Second pressing filtering liquid also then flows into third neutralization reaction tank 8;This
The main component of two filtrates is calcirm-fluoride, recyclable to be recycled as smelting flux.
Third neutralization reaction tank 8, water inlet are connect respectively with above-mentioned 5 and second plate and frame filter press 7 of causticization reactor.It is above-mentioned
Causticization supernatant and acid wash water carry out third neutralization reaction in the retort, obtain third neutralization reaction mixed liquor.
Second aspect, the method that nickelous carbonate is extracted from acid-washing stainless steel waste mixed acid, it is preferred to use system shown in FIG. 1 is come
It completes, includes the following steps:
Step 1: the first neutralization reaction:To collecting in the first neutralization reaction tank 1 slowly (flow control in waste mixed acid
In 100-200ml/min, preferably 150ml/min) to add in neutralizer (preferably sodium carbonate liquor) to pH value be 4.0-6.0,
Carry out the first neutralization reaction;0.5-2h, preferably 1h are stood again, obtain the first neutralization reaction mixed liquor, including:Waste mixed acid
In iron ion generation ferric hydroxide precipitate, chromium ion generation chromium hydroxide precipitation, unprecipitated nickel ion.
The mass percent concentration of above-mentioned sodium carbonate liquor is 10% to saturation, preferably 25~30%.
In this step, the formation of the precipitation of iron ion and chromium ion in waste mixed acid is realized.It is needed when adding in neutralizer
It is slowly added to, is because metal ion content is high in waste mixed acid, as rapidly joined, easily makes nickel ion in the high alkali dense in part
Also precipitation is formed under degree, is swept along with iron, chromium precipitation, it is therefore necessary to be slowly added to.
In this step, nickel ion will not generate precipitation, be because:Ferric ion and the pH value of chromium ion precipitation 5~
6, and the pH value that nickel ion starts precipitation is more than 7.
Illustratively, in this step flow velocity can be 100ml/min, 120ml/min, 150ml/min, 180ml/min,
Arbitrary value or arbitrary numberical range therebetween in 200ml/min;PH value can be arbitrary in 4.0,4.5,5.0,5.5,6.0
Value or arbitrary numberical range therebetween;Time of repose can be arbitrary value or arbitrary in 0.5h, 1h, 1.5h, 1.8h, 2.0h
Therebetween numberical range;Sodium carbonate liquor concentration can be arbitrary value or arbitrary in 10%, 15%, 20%, 25%, 30%
Therebetween numberical range.
Step 2: the first separation:Above-mentioned first neutralization reaction mixed liquor is carried out first point by above-mentioned horizontal centrifuge 2
From processing, the first separating filtrate and the first separation filter residue are respectively obtained.The first separation filter residue mainly includes ferric hydroxide precipitate
And chromium hydroxide precipitation, above two precipitation carry out subsequent metal recovery work by way of sintering-smelting.
In this step, the separation of iron ion in waste mixed acid, chromium ion and nickel ion is realized.Above-mentioned first separation filter residue
Containing iron, chromium, but not containing sulfate, the corrosion to agglomerating plant is avoided when recycling metal using sintering-smelting, is not increased
The desulfurization of smelting is added to bear.
Step 1: in two, the purpose of above-mentioned first neutralization reaction is:Most iron ion, chromium ion are precipitated out,
And nickel ion is stayed in the first separating filtrate.It is above-mentioned first separation purpose be:By the iron content of the first neutralization reaction mixed liquor, chromium
Precipitate separation of solid and liquid, obtain solid phase iron, chromium material, the liquid phase containing nickel ion need in the steps afterwards, by add sodium carbonate with
Nickel ion reaction production nickelous carbonate precipitation.
Step 3: the second neutralization reaction:In the second neutralization reaction tank 3, neutralizer is added in above-mentioned first separating filtrate
(preferably sodium carbonate liquor) adjusts pH value to carry out the second neutralization reaction to 8.0-10.0, obtain the second neutralization reaction mixed liquor;
In second neutralization reaction, main process is the nickelous carbonate precipitation of the nickel ion generation in solution, and nickelous carbonate precipitation is included in
In second neutralization reaction mixed liquor.
The mass percent concentration of above-mentioned sodium carbonate liquor is 10% to saturation, preferably 25~30%.
In this step, the generation of nickelous carbonate in waste mixed acid is realized.In this step, the nickelous carbonate in the second separation concentrated solution
Sinking speed is fast, and reaction liquid energy is made to continuously enter subsider, and supernatant continuously filters out subsider, and solid-liquor separation speed is fast, processing
Amount is big, can work continuously.
Illustratively, in this step pH value can be in 8.0,8.5,9.0,9.5,10.0 arbitrary value or it is arbitrary therebetween
Numberical range;Sodium carbonate liquor concentration can be in 10%, 15%, 20%, 25%, 30% arbitrary value or it is arbitrary therebetween
Numberical range.
Step 4: the second separation:Above-mentioned second neutralization reaction mixed liquor is carried out by precipitating separating tank 4 at the second separation
Reason, respectively obtains the second separation supernatant and the second separation concentrated solution.Second separation concentrated solution is located at separation trench bottom, flows into
First plate and frame filter press 6 carries out the first press filtration processing, obtains the first pressing filtering liquid and the first filtrate.First filtrate is mainly heavy
The nickelous carbonate in shallow lake, prepares dilval by way of direct-reduction;It is anti-that first pressing filtering liquid preferably then flows into above-mentioned causticization
Tank 5 is answered, can also individually store otherwise processed.In this step, the basic recycling of nickel ion is realized.This step obtains nickelous carbonate
Nickel grade for 30-50%, the major impurity of the first filtrate is iron, chromium that precipitation is brought into etc..This first filtrate is nickelic original
Material, can obtain dilval, the metal nickel content of dilval is up to 40-85% with the method for direct-reduction.By nickelous carbonate
Direct-reduction dilval avoids existing feed throughput during other low nickel raw material smelting ferronickels big, alloy yield (yield
=(product yield/material quantity) × 100%) it is low, energy consumption is high, various disadvantages that pollutant emission adversely affects environment
End.
Step 5: prepared by dilval:
Above-mentioned first filtrate (predominantly nickelous carbonate) is carried out solid phase reduction (to carry out under nonfused state in material
Reduction) processing, obtain dilval.It specifically includes:
Above-mentioned first filtrate (predominantly nickelous carbonate) is subjected to solid phase reduction with carbon in 1000-1250 DEG C (preferably 1150 DEG C)
Processing, obtains reduzate, i.e. dilval.
In above-mentioned solid phase reduction treatment, reduction process is:When material is heated to 350 DEG C, nickelous carbonate is decomposed into nickel oxide
With carbon dioxide, 750 DEG C or more are continuously heating to, carbon generates carbon monoxide with oxygen, and nickel oxide obtains gold with reaction of carbon monoxide
Belong to nickel, release carbon dioxide, carbon dioxide reacts generation carbon monoxide with red-hot carbon, continues reduction-oxidation nickel.Reaction equation is:C+
O2→ CO ↑, NiO+CO → Ni+CO2↑, CO2+C→2CO。
Nickel content height depends on the content of nickel in nickelous carbonate in the dilval that above-mentioned first filtrate restores;Carbonic acid
Nickel content height shows that the impurity contents such as iron therein, chromium are few in nickel;Nickel grade is just high in dilval after reduction.
Nickelous carbonate restore when with carbon according to nickel grade height and becoming, with carbon ratio be 10-20%, preferably 15%;It should be with carbon
Than referring to:During above-mentioned first filtrate (predominantly nickelous carbonate) supplying carbon, the mass percent of carbon and above-mentioned first filtrate.
Illustratively, in this step solid phase reduction temperature can be 1000 DEG C, 1050 DEG C, 1100 DEG C, 1150 DEG C, 1200
DEG C, arbitrary value or arbitrary numberical range therebetween in 1250 DEG C;With carbon ratio can be 10%, 12%, 15%, 18%,
Arbitrary value or arbitrary numberical range therebetween in 20%.
As preferred embodiment, the second separation supernatant and the first pressing filtering liquid in step 4 continue step
Six-eight processing, further to carry out purified treatment.
Step 6: causticizing reaction:It is added in into the second separation supernatant and the first pressing filtering liquid for flowing into causticizing reaction tank 5 severe
Agent is adjusted to pH value as 11.0-14.0, carries out causticizing reaction on this condition, obtains caustic precipitation (main component is calcirm-fluoride)
With causticization supernatant (including sodium hydroxide, calcium nitrate).The causticization supernatant then flows into transfer retort 8, as it
The raw material of his production technology carries out other processing.
The mass percent concentration of above-mentioned calcium hydroxide suspension is 30%-90%, preferably 40-50%.
In this step, above-mentioned second separation supernatant adds in calcium hydroxide causticization, obtains mainly containing sodium nitrate and sodium fluoride
Calcium fluoride precipitate and the causticization supernatant including sodium hydroxide, the mixed solution of calcium nitrate.The purpose of above-mentioned causticization is:1) it removes
Fluorine ion in water, 2) basicity of solution is improved.
The causticization supernatant that this step obtains can be used for replacing acid wash water neutralizer, so as to reduce the acid wash water of processing
Water consumption.
Illustratively, above-mentioned pH value can be arbitrary value or arbitrary the two in 11.0,12.0,13.0,14.0 in this step
Between numberical range;The mass percent concentration of calcium hydroxide suspension can be 30%, 40%, 45%, 50%, 60%,
70%th, arbitrary value or arbitrary numberical range therebetween in 80%, 90%.
Step 7: the second press filtration:The above-mentioned caustic precipitation enters the second plate and frame filter press 7 and carries out the second press filtration processing, obtains
To the second pressing filtering liquid and the second filtrate.Second pressing filtering liquid also then flows into third neutralization reaction tank 8.
The main component of the second filtrate that this step obtains is calcirm-fluoride, recyclable to be recycled as smelting flux.This step
Suddenly the second pressing filtering liquid obtained is mainly low-concentration sodium hydroxide solution, and the treatment of wastes with processes of wastes against one another can be realized for handling acid wash water,
With environmental benefit.
Step 8: third neutralization reaction:Above-mentioned causticization supernatant enters in third neutralization reaction tank 8, is 2.0- with pH value
3.0 acid wash waters carry out third neutralization reaction, obtain third neutralization reaction mixed liquor.
In this step, which utilizes the alkalinity of sodium hydroxide, and neutralization reaction, generation occurs with acid wash water
Third neutralization reaction mixed liquor in alkalescent, after filtering off residue, drainage, which is passed through, to be returned to out production line in double purification and reuses.
To sum up, metal ion is mainly iron, chromium, nickel in waste mixed acid of the invention, obtains the precipitation of above-mentioned metallic element
PH value is different, and iron ion, chromium ion are precipitated in pH value 4.0-6.0, and nickel ion can just be precipitated when pH value is more than 7, accordingly
The pH value of solution can be controlled, iron ion therein, chromium ion and nickel ion is made to be precipitated out respectively in different steps.
The principle of the processing method of the present invention is as follows:
1) for stainless steel in scale removal, base material can generate nitrate with nitric acid reaction, and nitrate is anti-with hydrofluoric acid again
Fluoride, reaction equation should be generated (in formulas below, Me represents metallic element):
Me+4HNO3=Me (NO3)3+NO↑+2H2O
Me(NO3)3+ 3HF=MeF3+3HNO3
Overall reaction Me+HNO3+ 3HF=MeF3+NO↑+2H2O
The nitration mixture nitric acid and proportioning (mass fraction) coefficient of hydrofluoric acid actually prepared are more than net reaction, in mixed acid liquid
Nitrate cannot react.Meanwhile nickel reacts with hydrofluoric acid and can be difficult to reaction in Surface Creation fluorine protective film.Therefore,
Nickel mainly exists in waste mixed acid with nickel nitrate.
2) nickel nitrate is reacted with sodium carbonate, generates nickelous carbonate, and reaction equation is:
Ni(NO3)2+Na2CO3=NiCO3↓+2NaNO3
3) sodium carbonate reacts generation sodium nitrate with nitric acid and hydrofluoric acid and sodium fluoride, reaction equation are:
2HNO3+Na2CO3=2NaNO3+CO2↑+H2O
2HF+Na2CO3=2NaF+CO2↑+H2O
4) sodium nitrate obtains sodium hydroxide with sodium fluoride with calcium hydroxide causticization, and reaction equation is:
2NaNO3+Ca(OH)2=Ca (NO3)2+2NaOH
2NaF+Ca(OH)2=CaF2↓+2NaOH
With reference to specific embodiment, the present invention is further explained.It should be understood that these embodiments be only used for the present invention without
For limiting the scope of the invention.Externally it should be understood that after present disclosure has been read, those skilled in the art are to this hair
Bright to make various changes or modifications, these equivalent forms also fall within the scope of the appended claims of the present application.
Embodiment 1
The present embodiment is using the system that nickelous carbonate is extracted in the slave acid-washing stainless steel waste mixed acid of Fig. 1;It gives up from acid-washing stainless steel
The method that nickelous carbonate is extracted in nitration mixture is specific as follows:
(1) first neutralization reaction:1000ml waste mixed acids are taken, with the sodium carbonate liquor of mass percent concentration 25% with flow velocity
150ml/min is added in waste mixed acid, and pH value is adjusted to stand 1h to 4.5.
(2) first separation:The obtains the first separation filter residue after a separation, detects weight of iron percentage composition 19.19% in slag,
Chromium mass percentage 2.11%, nickel mass percentage 0.46%.
(3) second neutralization reactions:First separating filtrate continues plus the sodium carbonate liquor of mass percent concentration 25%, adjusts PH
It is worth to 9.0.
(4) second separation:Second separation and the first press filtration again, the obtained main component of the first filtrate are nickelous carbonate, are examined
Survey the first filtrate weight of iron percentage composition 1.2%, chromium mass percentage 4.5%, nickel mass percentage 32.77%.
(5) nickelous carbonate reduction dilval:First filtrate is incorporated coke with 15% with carbon ratio, in 1150 DEG C also
Original obtains dilval.
After testing, in the dilval, nickel mass percentage is 56.32%.
The processing of step (6)-(8) is carried out to the second separation supernatant and the first pressing filtering liquid, further to carry out at purification
Reason.
(6) causticizing reaction:Supernatant and the first pressing filtering liquid mass percent are detached as 30% milk of lime tune by second
PH value obtains causticization supernatant and caustic precipitation to 14.0.
(7) second press filtrations:Caustic precipitation is subjected to the second press filtration processing, obtains the second pressing filtering liquid and the second filtrate.
(8) third neutralization reaction:Second pressing filtering liquid and causticization supernatant are mixed, the acidity for neutralizing pH value 2.4 is washed
Water, pH value to 8.5, the water outlet weight of iron percentage composition 1.37mg/l after neutralization, chromium mass percentage 2.05mg/l, nickel are not examined
Go out.
Embodiment 2
The present embodiment is using the system that nickelous carbonate is extracted in the slave acid-washing stainless steel waste mixed acid of Fig. 1;It gives up from acid-washing stainless steel
The method that nickelous carbonate is extracted in nitration mixture is specific as follows:
(1) first neutralization reaction:2000ml waste mixed acids are taken, are added in the sodium carbonate liquor of saturation with flow velocity 200ml/min
In waste mixed acid, pH value is adjusted to stand 1h to 5.5.
(2) first separation:The obtains the first separation filter residue after a separation, detects weight of iron percentage composition 17.92% in slag,
Chromium mass percentage 1.67%, nickel mass percentage 1.4%.
(3) second neutralization reactions:First separating filtrate continues plus the sodium carbonate liquor of mass percent concentration 25%, adjusts PH
It is worth to 9.5.
(4) second separation:Second separation and the first press filtration again, the obtained main component of the first filtrate are nickelous carbonate, are examined
Survey the first filtrate weight of iron percentage composition 0.8%, chromium mass percentage 5%, nickel mass percentage 39.21%.
(5) nickelous carbonate reduction dilval:First filtrate is incorporated coke with 15% with carbon ratio, in 1150 DEG C also
Original obtains dilval.
After testing, in the dilval, nickel content 68.94%.
The processing of step (6)-(8) is carried out to the second separation supernatant and the first pressing filtering liquid, further to carry out at purification
Reason.
(6) causticizing reaction:By the second separation supernatant and the first pressing filtering liquid milk of lime tune pH value to 14.0, causticization is obtained
Supernatant and caustic precipitation.
(7) second press filtrations:Caustic precipitation is subjected to the second press filtration processing, obtains the second pressing filtering liquid and the second filtrate.
(8) third neutralization reaction:Second pressing filtering liquid and causticization supernatant are mixed, the acidity for neutralizing pH value 2.6 is washed
Water, pH value to 8.0, the water outlet chromium mass percentage 0.18mg/l after neutralization, nickel parts per million concentration 8ppm, iron do not detect.
Embodiment 3
The present embodiment is using the system that nickelous carbonate is extracted in the slave acid-washing stainless steel waste mixed acid of Fig. 1;It gives up from acid-washing stainless steel
The method that nickelous carbonate is extracted in nitration mixture is specific as follows:
(1) first neutralization reaction:2000ml waste mixed acids are taken, by the sodium carbonate liquor of mass percent concentration 25% with flow velocity
100ml/min is added in waste mixed acid, and pH value is adjusted to stand 1h to 6.0.
(2) first separation:The obtains the first separation filter residue after a separation, detects weight of iron percentage composition 20% in slag, chromium
Mass percentage 4.5%, nickel mass percentage 3%.
(3) second neutralization reactions:First separating filtrate continues plus the sodium carbonate liquor of mass percent concentration 25%, adjusts PH
It is worth to 9.8.
(4) second separation:Second separation and the first press filtration again, the obtained main component of the first filtrate are nickelous carbonate, are examined
Survey the first filtrate weight of iron percentage composition 0.34%, chromium mass percentage 0.21%, nickel mass percentage 45.26%.
(5) nickelous carbonate reduction dilval:First filtrate is incorporated coke with 15% with carbon ratio, in 1200 DEG C also
Original obtains dilval.
After testing, in the dilval, nickel mass percentage is 83.06%.
The processing of step (6)-(8) is carried out to the second separation supernatant and the first pressing filtering liquid, further to carry out at purification
Reason.
(6) causticizing reaction:Supernatant and the first pressing filtering liquid mass percent concentration are detached as 35% lime by second
Breast adjusts pH value to obtain causticization supernatant and caustic precipitation to 14.0.(7) second press filtrations:Caustic precipitation is carried out at the second press filtration
Reason, obtains the second pressing filtering liquid and the second filtrate.
(8) third neutralization reaction:Second pressing filtering liquid and causticization supernatant are mixed, the acidity for neutralizing pH value 2.6 is washed
Water, pH value to 8.0, the chromium mass percentage 0.15mg/l of the water outlet after neutralization, nickel parts per million concentration 5ppm, iron million divide
Specific concentration 3ppm.
Embodiment 4
The present embodiment is using the system that nickelous carbonate is extracted in the slave acid-washing stainless steel waste mixed acid of Fig. 1;It gives up from acid-washing stainless steel
The method that nickelous carbonate is extracted in nitration mixture is specific as follows:
(1) first neutralization reaction:1500ml waste mixed acids are taken, by the sodium carbonate liquor of mass percent concentration 30% with flow velocity
150ml/min is added in waste mixed acid, and pH value is adjusted to stand 0.5h to 4.5.
(2) first separation:The obtains the first separation filter residue after a separation, detects weight of iron percentage composition 18.85% in slag,
Chromium mass percentage 3.7%, nickel mass percentage 2.8%.
(3) second neutralization reactions:First separating filtrate continues plus the sodium carbonate liquor of mass percent concentration 35%, adjusts PH
It is worth to 10.0.
(4) second separation:Second separation and the first press filtration again, the obtained main component of the first filtrate are nickelous carbonate, are examined
Survey the first filtrate weight of iron percentage composition 1.5%, chromium mass percentage 3.2%, nickel mass percentage 30.77%.
(5) nickelous carbonate reduction dilval:First filtrate is incorporated coke with 10% with carbon ratio, in 1000 DEG C also
Original obtains dilval.
After testing, in the dilval, nickel mass percentage content is 50.5%.
The processing of step (6)-(8) is carried out to the second separation supernatant and the first pressing filtering liquid, further to carry out at purification
Reason.
(6) causticizing reaction:Supernatant and the first pressing filtering liquid mass percent concentration are detached as 35% lime by second
Breast adjusts pH value to obtain causticization supernatant and caustic precipitation to 14.0.
(7) second press filtrations:Caustic precipitation is subjected to the second press filtration processing, obtains the second pressing filtering liquid and the second filtrate.
(8) third neutralization reaction:Second pressing filtering liquid and causticization supernatant are mixed, the acidity for neutralizing pH value 2.5 is washed
Water, pH value to 8.0, the chromium mass percentage 0.5mg/l of the water outlet after neutralization, nickel mass percentage 0.05mg/l, iron hundred
Specific concentration 2ppm very much.
Embodiment 5
The present embodiment is using the system that nickelous carbonate is extracted in the slave acid-washing stainless steel waste mixed acid of Fig. 1;It gives up from acid-washing stainless steel
The method that nickelous carbonate is extracted in nitration mixture is specific as follows:
(1) first neutralization reaction:1800ml waste mixed acids are taken, by the sodium carbonate liquor of mass percent concentration 20% with flow velocity
120ml/min is added in waste mixed acid, and pH value is adjusted to stand 2h to 4.5.
(2) first separation:The obtains the first separation filter residue after a separation, detects weight of iron percentage composition 19.75% in slag,
Chromium mass percentage 2.81%, nickel mass percentage 1.0%.
(3) second neutralization reactions:First separating filtrate continues plus the sodium carbonate liquor of mass percent concentration 40%, adjusts PH
It is worth to 9.0.
(4) second separation:Second separation and the first press filtration again, the obtained main component of the first filtrate are nickelous carbonate, are examined
Survey the first filtrate weight of iron percentage composition 1.0%, chromium mass percentage 0.7%, nickel mass percentage 31.5%.
(5) nickelous carbonate reduction dilval:First filtrate is incorporated coke with 20% with carbon ratio, in 1250 DEG C also
Original obtains dilval.
After testing, in the dilval, nickel mass percentage is 51.0%.
The processing of step (6)-(8) is carried out to the second separation supernatant and the first pressing filtering liquid, further to carry out at purification
Reason.
(6) causticizing reaction:Supernatant and the first pressing filtering liquid mass percent concentration are detached as 40% lime by second
Breast adjusts pH value to obtain causticization supernatant and caustic precipitation to 12.0.
(7) second press filtrations:Caustic precipitation is subjected to the second press filtration processing, obtains the second pressing filtering liquid and the second filtrate.
(8) third neutralization reaction:Second pressing filtering liquid and causticization supernatant are mixed, the acidity for neutralizing pH value 2.4 is washed
Water, pH value to 8.5, the chromium parts per million concentration 4ppm of the water outlet after neutralization, nickel mass percentage 0.8mg/l, iron do not detect.
Embodiment 6
The present embodiment is using the system that nickelous carbonate is extracted in the slave acid-washing stainless steel waste mixed acid of Fig. 1;It gives up from acid-washing stainless steel
The method that nickelous carbonate is extracted in nitration mixture is specific as follows:
(1) first neutralization reaction:1200ml waste mixed acids are taken, by the sodium carbonate liquor of mass percent concentration 30% with flow velocity
180ml/min is added in waste mixed acid, and pH value is adjusted to stand 1.75h to 4.5.
(2) first separation:The obtains the first separation filter residue after a separation, detects weight of iron percentage composition 16.55% in slag,
Chromium mass percentage 4.26%, nickel mass percentage 0.5%.
(3) second neutralization reactions:First separating filtrate continues plus the sodium carbonate liquor of mass percent concentration 45%, adjusts PH
It is worth to 8.0.
(4) second separation:Second separation and the first press filtration again, the obtained main component of the first filtrate are nickelous carbonate, are examined
Survey the first filtrate weight of iron percentage composition 0.75%, chromium mass percentage 2.5%, nickel mass percentage 32.2%.
(5) nickelous carbonate reduction dilval:First filtrate is incorporated coke with 18% with carbon ratio, in 1150 DEG C also
Original obtains dilval.
After testing, in the dilval, nickel mass percentage is 51.6%.
The processing of step (6)-(8) is carried out to the second separation supernatant and the first pressing filtering liquid, further to carry out at purification
Reason.
(6) causticizing reaction:Supernatant and the first pressing filtering liquid mass percent concentration are detached as 45% lime by second
Breast adjusts pH value to obtain causticization supernatant and caustic precipitation to 13.0.
(7) second press filtrations:Caustic precipitation is subjected to the second press filtration processing, obtains the second pressing filtering liquid and the second filtrate.
(8) third neutralization reaction:Second pressing filtering liquid and causticization supernatant are mixed, the acidity for neutralizing pH value 2.6 is washed
Water, pH value to 8.0, the chromium mass percentage 0.8mg/l of the water outlet after neutralization, nickel mass percentage 0.03mg/l, iron hundred
Specific concentration 5ppm very much.
Comparative example 1
The present embodiment is using the system that nickelous carbonate is extracted in the slave acid-washing stainless steel waste mixed acid of Fig. 1;It gives up from acid-washing stainless steel
The method of nickelous carbonate is extracted in nitration mixture in addition to following operation, it is identical with embodiment 3.
(1) first neutralization reaction:2000ml waste mixed acids are taken, the sodium carbonate liquor of mass percent concentration 25% is rapid
(addition 300ml/min) adds in waste mixed acid, and pH value is adjusted to stand 1h to 6.0.
In later the step of (2), weight of iron percentage composition 18.1% in slag, chromium mass percentage 3.5%, nickel matter are detected
Measure percentage composition 5.85%;In step (4), the first filtrate weight of iron percentage composition 2.3%, chromium mass percentage are detected
1.5%, nickel mass percentage 15.8%;In step (5), the nickel mass percentage for detecting dilval is 20.8%.
It can be seen that office in waste mixed acid will be made if not using the operation for being slowly added to sodium carbonate liquor in step (1)
Portion's pH value is excessive, and nickel ion comes out with iron ion, chromium ion coprecipitation, so as to which the nickel for making the first filtrate in step (2) contains
Amount reduces, and the nickel content in the dilval that step (4) obtains also reduces.