CN1940097A - Extraction of chromium from mud containing chromium by sodium-salt calcination - Google Patents
Extraction of chromium from mud containing chromium by sodium-salt calcination Download PDFInfo
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- CN1940097A CN1940097A CNA2005100301372A CN200510030137A CN1940097A CN 1940097 A CN1940097 A CN 1940097A CN A2005100301372 A CNA2005100301372 A CN A2005100301372A CN 200510030137 A CN200510030137 A CN 200510030137A CN 1940097 A CN1940097 A CN 1940097A
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- chromium
- sodium
- sodium salt
- roasting
- sludge
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
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- Treatment Of Sludge (AREA)
- Manufacture And Refinement Of Metals (AREA)
Abstract
Extraction of chromium from chromium-contained sludge by sodium salt calcining is carried out by treating sludge, mixing sodium salt with chromium-contained sludge, calcining at 700 degree for 40mins, cooling and leaching out. The sodium salt consists of sodium hydrate, sodium carbonate, sodium nitrate and filler in proportion of Cr2O3:NaNO3:Na2CO3:NaOH=1:1.5-4:3-8:8-20; filler is residue in proportion of filler: chromium slag:0.8-1.5:1. It has short reactive time, low calcining temperature and no secondary environmental pollution and can save energy resources.
Description
Technical field
The present invention relates to the processing of chromium-bearing sludge, particularly a kind of method of extracting chromium in the chromium-bearing sludge by sodium salt oxidizing roasting.
Background technology
At present, the chromate waste water that produces in the industrial production is handled with the chemical reduction or the biological reducing precipitator method usually, chromium in the waste water can be accomplished qualified discharge substantially, but, handle waste water by the above-mentioned precipitator method, still have trivalent chromium to exist in the mud that finally precipitates, will not cause severe contamination (carcinogens that international hygiene circle is generally acknowledged) to environment if do not add processing.For this reason, the precipitating sludge that contains chromium still needs to be further processed, so that reclaim chromium wherein, thereby reduces the pollution to environment.
For from chromium-bearing sludge, reclaiming chromium, people adopt acid, alkali stripping method usually, but this method exists narrow application range, weakness that leaching yield is low, this is because acid is molten, the molten condition of alkali is relatively harsher, generally leaching effect preferably to be arranged just under the high-temperature high concentration condition according to the literature, if leaching yield is then very low under the normal temperature low consistency conditions, simultaneously, because of other heavy metal elements such as iron in the chromium mud also together enter leach liquor with chromium, thereby cause the defective such as purification difficult, operating procedure complexity, long flow path of chromium.
The Minle County Chemical Plant discloses a kind of " calcium-free roasting is produced Sodium chromate technology " (CN1579947A) on February 16th, 2005, this method is to be that furnace charge carries out roasting with chromite, soda ash, three kinds of powder uniform mixing of no calcium chromium slag, maturing temperature is more than 1000 ℃, time is about 4 hours, grog with water extraction after, the leaching yield of chromium (discloses among the patent CN 1579947A at 90-94%, the oxidation ratio of Cr is about 91%-95%, chromic leaching yield is more than 99%, and the rate of recovery of therefore amounting to into chromium is about 90%-94%).But the process object of the technology that patent CN1579947A discloses is a chromite, and it is high a lot of that the relative chrome waste water of its chromium content is wanted, so deal with relatively easy; Simultaneously, the roasting temperature of reaction of this Patent publish is more than 1000 ℃, and the roasting reaction times is about 4 hours, temperature height, the long serious consumption that has caused the energy of time; The oxidation ratio of Cr only is about 91%-95% in this patent technology, chromic content＜0.15% in the residue.
Summary of the invention
The objective of the invention is chromium-bearing sludge is carried out innoxious and recycling treatment, to reach the purpose of eliminating environmental pollution and chromium resource comprehensive utilization.
For achieving the above object, the invention provides a kind of method, comprise the steps: sludge treatment → sodium salt mixing → roasting → cooling → leaching with chromium in the sodium-salt calcination extraction chromium-bearing sludge.
Wherein, the particular case of above-mentioned each processing step is as follows:
A) sludge treatment: in this step, handle mud according to the step of press filtration → drying → ashing → grinding.At first, the chromium-bearing sludge press filtration is become mud cake, water content is controlled at 50%～70%; 110 ℃ of drying and dehydratings in baking oven then, about 4 hours of time; Organism is decomposed in then 300 ℃～400 ℃ calcinations in retort furnace, and the mud cake after the ashing becomes chromium residue; Adopt ordinary method that chromium residue is ground refinement at last.
B) sodium salt mixes: add sodium hydroxide, yellow soda ash, SODIUMNITRATE and stopping composition and carry out oxidizing roasting.The effect of above-mentioned sodium salt is can reduce the temperature of roasting reaction for chromium provides alkaline oxygenated atmosphere: NaOH; Na
2CO
3Can play the effect of loose furnace charge; NaNO
3Promote the raising of speed of reaction as oxygenant; With Cr in the chromium slag
2O
3Content be radix, the mol ratio that sodium salt adds is Cr
2O
3: NaNO
3: Na
2CO
3: NaOH=1: 1.5～4: 3～8: 8～20.Stopping composition is the residue after the chromium leaching, and its effect is to avoid furnace charge knot wall; Stopping composition and chromium slag (promptly dry ashing after chromium-bearing sludge) are as stopping composition to return oxidizing roasting at 0.8～1.5: 1 with weight ratio, and (stopping composition is a magnesiumcarbonate first) can effectively avoid furnace charge knot wall problem, NaNO in the roasting process
3And Na
2CO
3Degradation production be nitrogen and carbonic acid gas, can not cause secondary pollution.
C) roasting: behind the material uniform mixing, 700 ℃ of oxidizing roastings 40 minutes, making the trivalent chromium conversion in the chromium slag was sexavalent chrome.
D) cooling: grog is cooled to 50 ℃～70 ℃ at normal temperatures.
E) leach:, cooled grog leaches with 70 ℃～80 ℃ hot water, and the leaching yield of Cr can reach 99% in the chromium slag.Fe in the chromium-bearing sludge can not transfer in the leach liquor, this be because mud in Fe in podzolic process with Fe
2O
3Form exist, under the high-temperature alkaline condition not can with other substance reactions in the material, need not to carry out Fe, Cr and separate, for condition has been created in the utilization again of chromium resource.Grog obtains chromium acid sodium solution after the hot water leaching, purified back obtains chrome yellow with the lead nitrate reaction.
Compared with prior art, the invention has the advantages that: 1) applied widely, the recovery of the chromium in the precipitating sludge that can be used for producing in chemical reduction method or the biological reducing method processing waste water containing chrome treating processes; 2) carry out oxidizing roasting with three kinds of sodium salts such as sodium hydroxide, yellow soda ash, SODIUMNITRATE, its maturing temperature is low, and the reaction times is short; 3) because the synergy of three kinds of sodium salts, the oxidation ratio height of chromium in the chromium slag, the leaching yield of chromium is greater than 99%; 4) use the residue after chromium leaches to be stopping composition, can avoid the knot wall problem of furnace charge, also alleviated simultaneously second environmental pollution.
Description of drawings
Fig. 1 is a process flow sheet according to a preferred embodiment of the invention.
Embodiment
As shown in Figure 1, in a preferred embodiment of the invention, the technical process that contains the wet mud of chromium is: mud → press filtration → drying → ashing → grinding → sodium salt mixing → roasting → cooling → leaching.
Promptly, contain the wet mud of chromium through carrying out roasting after press filtration, drying, calcination, the grinding with after sodium hydroxide, yellow soda ash and SODIUMNITRATE are mixed, grog leaches with hot water, after solid-liquid separation (promptly filtering), obtain the raw material of chromium acid sodium solution again as the chromic salts product preparation, the residue part is as the stopping composition of next batch chromium slag roasting, and remainder is as Solid waste disposal.
Below be specifying of example 1-3 of the present invention.
Example one:
With certain sodium bisulfite is that the precipitating sludge that obtains after the reductive agent processing waste water containing chrome is a raw material, after press filtration in 110 ℃ baking oven drying and dehydrating, 300 ℃ of ashing after about 4 hours in the chromium slag content of chromium be 27.75%, amount to into Cr
2O
3Be 40.56%, sodium salt adds ratio (mol ratio) and is Cr
2O
3: NaNO
3: Na
2CO
3: NaOH=1: 1.5: 3: 8, the ratio (weight ratio) of stopping composition and chromium slag was 1.5: 1, through 700 ℃ of oxidizing roastings 40 minutes, was that the rate of recovery of 1: 4 hot water leaching back chromium is 99.5% with solid-to-liquid ratio, and the roasting process material does not have knot wall phenomenon.Leach liquor adds Ca (OH)
2After the dephosphorization, add Pb (NO again
3)
2Deng, obtain light chrome yellow (PbCrO
4PbSO
4) pigment, quality product satisfies the quality standard of GB/T 3184-93 lead-chrome yellow.
Example two:
With the precipitating sludge that obtains after certain micro-reduction method processing waste water containing chrome is raw material, and through drying and dehydrating, 350 ℃ of ashing are after about 4 hours in 110 ℃ of baking ovens after the press filtration, the content of chromium is 20.33% in the chromium slag, amounts to into Cr
2O
3Be 29.71%, it is Cr that sodium salt adds mol ratio
2O
3: NaNO
3: Na
2CO
3: NaOH=1: 2: 3.5: 10, the weight ratio of stopping composition and chromium slag was 0.8: 1, through 700 ℃ of oxidizing roastings 40 minutes, was that the rate of recovery of 1: 5 hot water leaching back chromium is 99.1% with the solid-liquid weight ratio, and iron does not detect, and the roasting process material does not have knot wall phenomenon.Leach liquor adds Ca (OH)
2After the dephosphorization, add Pb (NO again
3)
2, obtain medium chrome yellow medium yellow (PbCrO
4) pigment, quality product reaches GB/T 3184-93 lead-chrome yellow quality standard.
Example three:
The precipitating sludge that obtains with certain micro-reduction method processing waste water containing chrome is a raw material, and drying and dehydrating, 400 ℃ of ashing are after about 4 hours in 110 ℃ of baking ovens through press filtration, and the content of chromium is 11.89% in the chromium slag, amounts to into Cr
2O
3Be 17.38%, the sodium salt ratio of adding is Cr
2O
3: NaNO
3: Na
2CO
3: NaOH=1: 4: 8: 20, the ratio of stopping composition and chromium slag was 1: 1, through 700 ℃ of oxidizing roastings 40 minutes, was that the rate of recovery of 1: 3 hot water leaching back chromium is 99.4% with the solid-liquid weight ratio, and iron does not detect, and the roasting process material does not have knot wall phenomenon.Leach liquor adds Ca (OH)
2After the dephosphorization, add Pb (NO again
3)
2Deng, obtain light chrome yellow (PbCrO
4PbSO
4) pigment, quality product satisfies the quality standard of GB/T3184-93 lead-chrome yellow.
Claims (7)
1. extract the method for chromium in the chromium-bearing sludge with sodium-salt calcination, may further comprise the steps:
Sludge treatment → sodium salt mixing → roasting → cooling → leaching.
2. the method for claim 1 is characterized in that, the step of described sludge treatment comprises press filtration → drying → ashing → grinding.
3. method as claimed in claim 1 or 2 is characterized in that, also comprises filtering step after the described leaching step.
4. method as claimed in claim 1 or 2 is characterized in that, in described sodium salt blended step, according to Cr
2O
3: NaNO
3: Na
2CO
3: NaOH=1: 1.5～4: 3～8: 8～20 molar ratio ingredient mixes.
5. method as claimed in claim 1 or 2 is characterized in that, in the step of described roasting, the temperature of oxidizing roasting is controlled at about 700 ℃, and roasting time is 40 minutes.
6. method as claimed in claim 2 is characterized in that the step of described ashing is carried out in retort furnace, temperature is controlled at 300 ℃～400 ℃.
7. the method for claim 1 is characterized in that, the residue that obtains in described leaching step can be used as stopping composition and sodium salt together enters sodium salt blended step, and the weight ratio of described stopping composition and chromium slag is 0.8～1.5: 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100301372A CN100560755C (en) | 2005-09-29 | 2005-09-29 | Extract the method for chromium in the chromium-bearing sludge with sodium-salt calcination |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100301372A CN100560755C (en) | 2005-09-29 | 2005-09-29 | Extract the method for chromium in the chromium-bearing sludge with sodium-salt calcination |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1940097A true CN1940097A (en) | 2007-04-04 |
| CN100560755C CN100560755C (en) | 2009-11-18 |
Family
ID=37958619
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2005100301372A Expired - Fee Related CN100560755C (en) | 2005-09-29 | 2005-09-29 | Extract the method for chromium in the chromium-bearing sludge with sodium-salt calcination |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101818360A (en) * | 2010-03-16 | 2010-09-01 | 西安泰金工业电化学技术有限公司 | Method for removing waste titanium anode coating |
| CN102061397A (en) * | 2010-06-02 | 2011-05-18 | 四川龙蟒矿冶有限责任公司 | Method for recycling vanadium, chromium, titanium and iron from vanadium-titanium magnetite ore |
| CN104046783A (en) * | 2014-07-04 | 2014-09-17 | 西安建筑科技大学 | Method for recovering gold, silver and lead from cyanidation slag |
| CN106381394A (en) * | 2016-10-08 | 2017-02-08 | 河钢股份有限公司承德分公司 | Method for extracting chromium from high-chromium-content calcium-chromium slag |
| CN114540629A (en) * | 2021-12-30 | 2022-05-27 | 华南理工大学 | Method for extracting and recovering heavy metal chromium from metallurgical waste slag based on crystalline phase regulation |
-
2005
- 2005-09-29 CN CNB2005100301372A patent/CN100560755C/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101818360A (en) * | 2010-03-16 | 2010-09-01 | 西安泰金工业电化学技术有限公司 | Method for removing waste titanium anode coating |
| CN101818360B (en) * | 2010-03-16 | 2011-11-30 | 西安泰金工业电化学技术有限公司 | Method for removing waste titanium anode coating |
| CN102061397A (en) * | 2010-06-02 | 2011-05-18 | 四川龙蟒矿冶有限责任公司 | Method for recycling vanadium, chromium, titanium and iron from vanadium-titanium magnetite ore |
| CN104046783A (en) * | 2014-07-04 | 2014-09-17 | 西安建筑科技大学 | Method for recovering gold, silver and lead from cyanidation slag |
| CN104046783B (en) * | 2014-07-04 | 2016-04-13 | 西安建筑科技大学 | A kind of method reclaiming gold and silver and lead in cyanidation tailings |
| CN106381394A (en) * | 2016-10-08 | 2017-02-08 | 河钢股份有限公司承德分公司 | Method for extracting chromium from high-chromium-content calcium-chromium slag |
| CN114540629A (en) * | 2021-12-30 | 2022-05-27 | 华南理工大学 | Method for extracting and recovering heavy metal chromium from metallurgical waste slag based on crystalline phase regulation |
Also Published As
| Publication number | Publication date |
|---|---|
| CN100560755C (en) | 2009-11-18 |
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| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20091118 Termination date: 20170929 |