CN106277053A - A kind of preparation method of chromium oxide - Google Patents
A kind of preparation method of chromium oxide Download PDFInfo
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- CN106277053A CN106277053A CN201610591111.3A CN201610591111A CN106277053A CN 106277053 A CN106277053 A CN 106277053A CN 201610591111 A CN201610591111 A CN 201610591111A CN 106277053 A CN106277053 A CN 106277053A
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- chromium
- filter cake
- chromic
- starch
- oxide gel
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G37/00—Compounds of chromium
- C01G37/02—Oxides or hydrates thereof
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/80—Compositional purity
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Abstract
The invention discloses the preparation method of a kind of chromium oxide, comprise the following steps: (1) adds reducing agent to dichromate solution and obtains mixed solution, after mixed solution is heated to 100～170 DEG C of reactions, preserving heat after reaction ends 0.5～5.0h, obtain chromic oxide gel slurry；(2) chromic oxide gel slurry obtains filtrate and filter cake through solid-liquid separation, and filter cake is scrubbed and is dried to obtain chromic oxide gel powder body；(3) being mixed by the cleaning mixture of filtrate and filter cake, part returns in step (1) and is used for regulating pH value, and remainder is for neutralizing the chromium-containing sodium bisulfate produced in chromic anhydride production process；(4) calcining chromic oxide gel powder body, obtains chromium oxide；(5) adding reducing agent in the chromium-containing solution obtained after step (3) neutralizes chromium-containing sodium bisulfate, product obtains chromic oxide gel filter cake after solid-liquid separation.The present invention not only has significant economic benefit, and meets environmental requirement, is an effective way of chromic salts enterprise production.
Description
Technical field
The present invention relates to chromium salt production field, it particularly relates to chromium salt production uses bichromate hydro-thermal method prepare
The new method of chromium oxide.
Background technology
Conventional oxidation chromium industrial process mainly has two kinds.One is by bichromate and ammonium sulfate are carried out heat point
Solve reaction and prepare chromium oxide.This process contamination is less, but relative cost is higher.Although also the sulfur in traditional industry can be replaced with carbon
Acid ammonium, but reduction process to be protected by the strict carbon dioxide atmosphere that controls, and prevents chromium oxide the most oxidized, and it is deposited
Problem in technological operation difficulty.Two is to use bichromate sulphuric acid fusion method to produce chromic anhydride, and chromic anhydride decomposition method prepares oxygen
Change chromium.The method product quality is high, but technological process is long, and cost is the highest.Meanwhile, its sulphuric acid utilization rate is less than 50%, per ton
Chromic anhydride by-product 1.4t chromium-containing sodium bisulfate, and owing to indirectly using sulfur or sulphur compound, the sulfur content of product is high.
Flow process is short, low cost and be prone to put to use hydrothermal reduction method that hexavalent chrome reduction in solution directly becomes trivalent chromium have
The advantage such as big.Chromium acid sodium solution hydrothermal reduction, existing more patent report.
Patent documentation CN100999335A discloses with small-molecule substances such as sulfide, formaldehyde, methanol as reducing agent, CO2
For acidulant, high-temperature water hot preparation hydrated chromium oxide.But, the introducing of sulfide can affect the performance of chromium oxide.And formaldehyde and
Methanol etc. have certain toxicity, need to prevent with caution volatilization, explosion-proof etc. in production application.
Patent documentation CN1410356A discloses with sucrose, glucose or fructose as reducing agent, first uses CO2At low temperature
Under carry out pre-acidified, the most at high temperature carry out hydrothermal reduction, hydrated chromium oxide can be prepared, course of reaction needs CO2Enter
Row acidifying.
Patent documentation CN101456588A discloses and prepares hydrated chromium oxide, filter cake with starch and derivant thereof for reducing agent
The most scrubbed dinectly bruning obtains chromium oxide powder.But, using bichromate is that raw material there is problems of, and directly carries out water
Thermal response, rate of reduction is too fast, it is difficult to control, it is necessary to adds appropriate alkali regulation and controls course of reaction.Further, under high temperature,
Carbonate in filter cake chromic oxide gel reacts with the chromium oxide generation alkali fusion of generation in calcination process, regenerates Cr VI, leads
Cause chromic loss.
Above-mentioned disclosed technical scheme all exists that hydrothermal reaction process heating-up temperature is higher and bigger the lacking of energy consumption
Sunken needs overcome.
Summary of the invention
The main object of the present invention is for chrominm salt production technology present situation, it is provided that the low energy consumption of a kind of optimization, low cost system
The new method of standby chromium oxide.
The method preparing chromium oxide that the present invention provides, comprises the following steps:
(1) in the dichromate solution that pH value is 3.0～7.0, add reducing agent and obtain mixed solution, adding of reducing agent
Enter that amount is reducing agent/bichromate stoichiometric proportion 1.0～3.0 times, after mixed solution is heated to 100～170 DEG C of reactions,
Preserving heat after reaction ends 0.5～5.0h, obtains chromic oxide gel slurry；
(2) chromic oxide gel slurry obtains filtrate and filter cake through solid-liquid separation, and filter cake is scrubbed and dry, obtains chromic oxide gel
Powder body；
(3) being mixed by the cleaning mixture of filtrate and filter cake, part returns and is used for regulating pH value in step (1), and remainder is used
In neutralizing the chromium-containing sodium bisulfate produced in chromic anhydride production process；
(4) calcining chromic oxide gel powder body, the powder body after calcining is through washing and is dried, and obtains chromium oxide；This step obtains
Chromium oxide be pigmentary chromium oxide.
(5) chromium-containing solution obtained after step (3) neutralizes chromium-containing sodium bisulfate adds reducing agent to react, reaction
Product obtains chromic oxide gel filter cake after solid-liquid separation, and this chromic oxide gel filter cake washs according to step (2) and (4) and forges
Burn, obtain chromium oxide.The chromium oxide that this step obtains is inferior chromium oxide.
Preferably, step (1) described bichromate is potassium dichromate and/or sodium dichromate, and solution concentration is 10～350g/
L。
It is furthermore preferred that the degree of described dichromate solution is more than 100g/L.
Preferably, the reducing agent in described step (1) is starch and derivant, sugar or its mixture；
Described starch include pre-gelatinized starch, acidified starch, Oxytarch, dialdehyde starch, etherification starch, crosslinked starch and
One or more in graft copolymerization starch；
Described sugar is sucrose, fructose and/or glucose.
Preferably, calcining heat 500～1200 DEG C in described step (4), temperature retention time is 0.2～5.0h,
Preferably, the wash conditions in described step (2) and (4) is: washing liquid-solid ratio is 0.5:1～10:1, washing temperature
Spending 30～100 DEG C, washing times is 3～7 times, wash time 0.1～0.6h.
This method uses bichromate to be raw material, after using alkali regulation pH, it is not necessary to carbon dioxide is acidified, and low-temperature hydrothermal is reduced
Can prepare chromic oxide gel, available purity high (＞ 99.5%) after chromic oxide gel calcining, impurity are few, the chromium oxide of function admirable.
Filtrate and Cake Wash liquid that slurry after hydro-thermal reaction obtains after solid-liquid separation mix, and part returns dispensing and again carries out water
Thermal reduction, remainder, for neutralizing the chromium-containing sodium bisulfate produced in chromic anhydride production process, reduces the hydrogen obtained after neutralization
Chromium oxide is used for producing low-quality chromium oxide.
The present invention, compared with existing chromium oxide production technology, has the advantage that
(1) present invention is with sodium dichromate as raw material, no matter is in low concentration or high concentration range, all can realize percent reduction
Reach more than 99%.Reaction can prepare the chromium oxide of high-quality, and purity can be to more than 99.5%, and its performance reaches pigment after measured
The standard of level chromium oxide.
(2) present invention is with sodium dichromate as raw material, hydrothermal reduction mild condition, relatively other patent, and heating-up temperature is less than 170
DEG C, temperature reduces 30～50 DEG C, and energy consumption reduces by 10%～20%.Hydrated chromium oxide prepares chromium oxide through dehydration calcining, cleaning
Pollution-free.
(3) present invention process is simple, flow process is short, workable, with low cost, requires relatively low to the material of equipment,
It is easily achieved industrialized production.
(4) present invention process does not produce chromate waste water.The slurry after the hydro-thermal reaction filtrate through being filtrated to get and filter cake are washed
Washing liquid mixing, a part returns configuration sodium dichromate feed liquid, and another part is for neutralizing the chromium-containing sodium bisulfate that chromic anhydride produces, both
Recycling of alkali liquor can be realized, may be used for again the process of chromed leather wastes, not only can realize chrome oxide green and chromic anhydride
Coproduction, and environment friendly and pollution-free.
(5) present invention does not produce waste residue.Neutralize after chromium-containing sodium bisulfate, chromium-containing solution through reduction, washing and calcine can
Produce low-quality chromium oxide.
The technique of the present invention not only has significant economic benefit, and meets environmental requirement, is that chromic salts enterprise produces
Article one, effective way.
Accompanying drawing explanation
Fig. 1, present invention process schematic flow sheet.
Detailed description of the invention
The following is embodiments of the invention, it is only used as explanation of the invention and and unrestricted.
Embodiment 1.
Sodium dichromate is configured to the solution of 150g/L, and regulation pH is 4.0.The solution of mixing is placed in reactor, adds
Enter pre-gelatinized starch, addition be pre-gelatinized starch/sodium dichromate stoichiometric proportion be 2.5, mixed solution is heated to 120
DEG C, and it is incubated 4.0h.After reaction terminates, by chromic oxide gel slurries filtration.Filtrate measures sodium dichromate content, calculates reduction and converts
Rate is 99.3%.The filter cake being filtrated to get washs, and washing liquid-solid ratio is 5:1, wash temperature 50 DEG C, and washing times is 5 times,
Wash time 0.3h.After washing filtration cakes torrefaction and in 1100 DEG C calcine 0.5h.Calcination product is washed 4 times, temperature 80 DEG C, the time
0.2h, product obtains the pigment-level chromium oxide that purity is 99.2% after drying.Slurry after hydro-thermal reaction is through being filtrated to get
Filtrate and the mixing of Cake Wash liquid, a part returns dispensing, repeats the production process of pigment-level chromium oxide；Remaining mixed liquor is used for
Neutralizing the chromium-containing sodium bisulfate produced in chromic anhydride production process, after neutralization, feed liquid is low through reducing, wash, calcine and being dried to obtain
Quality chromium oxide.
Embodiment 2.
Sodium dichromate and potassium dichromate are configured to the solution of 200g/L, and regulation pH is 5.5.The solution of mixing is placed in instead
Answer in still, add acidified starch, addition be acidified starch/(sodium dichromate and potassium dichromate) stoichiometric proportion be 1.8, will be mixed
Close solution and be heated to 150 DEG C, and be incubated 2.0h.After reaction terminates, by pulp centrifuged for chromic oxide gel separation.Filtrate measures dichromic acid
Sodium and potassium dichromate content, calculating reduction conversion ratio is 99.6%.The filter cake of isolated washs, and washing liquid-solid ratio is 3:
1, wash temperature 90 DEG C, washing times is 4 times, wash time 0.5h.1.0h is calcined in 900 DEG C after filtration cakes torrefaction after washing.Forge
Burning product to wash 3 times, temperature 50 C, time 0.4h, product obtains the pigment-level chromium oxide that purity is 99.7% after drying.Water
The slurry after the thermal response filtrate through being filtrated to get and the mixing of Cake Wash liquid, a part returns dispensing, repeats pigment-level oxidation
The production process of chromium；Remaining mixed liquor is for neutralizing the chromium-containing sodium bisulfate produced in chromic anhydride production process, feed liquid after neutralization
Through reducing, wash, calcine and be dried to obtain low-quality chromium oxide.
Embodiment 3.
Potassium dichromate is configured to the mixed solution of 300g/L, and regulation pH is 6.8.The solution of mixing is placed in reactor
In, adding sucrose and copolymerization starch, addition is 1.8 for (sucrose and copolymerization starch)/potassium dichromate stoichiometric proportion, will mixing
Solution is heated to 160 DEG C, and is incubated 1.0h.After reaction terminates, by pulp centrifuged for chromic oxide gel separation.Filtrate measures potassium dichromate
Content, calculating reduction conversion ratio is 99.6%.The filter cake of isolated washs, and washing liquid-solid ratio is 2:1, wash temperature 70
DEG C, washing times is 3 times, wash time 0.3h.2.0h is calcined in 700 DEG C after filtration cakes torrefaction after washing.Calcination product washing 7
Secondary, temperature 70 C, time 0.6h, product obtains the pigment-level chromium oxide that purity is 99.5% after drying.After hydro-thermal reaction
The slurry filtrate through being filtrated to get and the mixing of Cake Wash liquid, a part returns dispensing, repeats the production of pigment-level chromium oxide
Journey；Remaining mixed liquor is for neutralizing the chromium-containing sodium bisulfate produced in chromic anhydride production process, and after neutralization, feed liquid is through reducing, washing
Wash, calcine and be dried to obtain low-quality chromium oxide.
Claims (6)
1. a preparation method for chromium oxide, comprises the following steps:
(1) in the dichromate solution that pH value is 3.0～7.0, add reducing agent and obtain mixed solution, the addition of reducing agent
For 1.0～3.0 times of reducing agent/bichromate stoichiometric proportion, after mixed solution is heated to 100～170 DEG C of reactions, reaction
It is incubated 0.5～5.0h after end, obtains chromic oxide gel slurry；
(2) chromic oxide gel slurry obtains filtrate and filter cake through solid-liquid separation, and filter cake is scrubbed and is dried to obtain chromic oxide gel powder body；
(3) being mixed by the cleaning mixture of filtrate and filter cake, part returns in step (1) and is used for regulating pH value, during remainder is used for
With the chromium-containing sodium bisulfate produced in chromic anhydride production process；
(4) calcining chromic oxide gel powder body, obtains chromium oxide；
(5) chromium-containing solution obtained after step (3) neutralizes chromium-containing sodium bisulfate adds reducing agent to react, product
Obtaining chromic oxide gel filter cake after solid-liquid separation, this chromic oxide gel filter cake washs according to step (2) and (4) and calcines,
To chromium oxide.
Method the most according to claim 1, it is characterised in that step (1) described bichromate is potassium dichromate and/or weight
Sodium chromate, solution concentration is 10～350g/L.
Method the most according to claim 2, it is characterised in that the degree of described dichromate solution is more than 100g/L.
Method the most according to claim 1, it is characterised in that the reducing agent in described step (1) is starch and derives
Thing and/or sugar；
Described starch includes pre-gelatinized starch, acidified starch, Oxytarch, dialdehyde starch, etherification starch, crosslinked starch and grafting
One or more in copolymerization starch；
Described sugar is sucrose, fructose and/or glucose.
Method the most according to claim 1, it is characterised in that calcining heat 500～1200 DEG C in described step (4), protects
The temperature time is 0.2～5.0h.
Method the most according to claim 1, it is characterised in that the wash conditions in described step (2) and (4) is: washing
Liquid-solid ratio is 0.5:1～10:1, wash temperature 30～100 DEG C, and washing times is 3～7 times, wash time 0.1～0.6h.
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107934993A (en) * | 2017-11-13 | 2018-04-20 | 陕西省商南县东正化工有限责任公司 | A kind of method for preparing anhydrous sodium sulfate using saltcake containing chromium |
| WO2018177222A1 (en) * | 2017-03-27 | 2018-10-04 | 福建欣宇卫浴科技股份有限公司 | System and process for treating for wastewater containing chromium |
| CN108862385A (en) * | 2018-09-10 | 2018-11-23 | 四川省银河化学股份有限公司 | The control method of partial size in a kind of production of chrome oxide green |
| CN109211718A (en) * | 2018-10-26 | 2019-01-15 | 湖北振华化学股份有限公司 | K in potassium bichromate production2The measuring method of O content |
| CN110156122A (en) * | 2018-11-02 | 2019-08-23 | 福建省隆辉环保工程有限公司 | Electroplating concentrated control zone sewage chromium mud recovery method |
| CN110407253A (en) * | 2019-07-08 | 2019-11-05 | 重庆理工大学 | A kind of method of barium chromate preparation chrome oxide green |
| CN114715939A (en) * | 2021-01-06 | 2022-07-08 | 中国科学院青海盐湖研究所 | Nano chromium sesquioxide and preparation method thereof |
| CN115069234A (en) * | 2022-06-29 | 2022-09-20 | 华南理工大学 | Method for preparing hollow CrO simultaneously by detoxication and purification of chromium-containing waste salt x /Al 2 O 3 Method for preparing catalyst and its application |
| CN115477327A (en) * | 2022-09-23 | 2022-12-16 | 绵阳光达环保科技有限责任公司 | Production process for producing hydroxyl chromic oxide by reducing sodium chromate with ethanol or methanol |
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| CN1410357A (en) * | 2001-10-10 | 2003-04-16 | 中国科学院过程工程研究所 | Method of preparing chromium oxide using wet reducing potassium bichromate or sodium bichromate |
| CN1424258A (en) * | 2003-01-09 | 2003-06-18 | 济南裕兴化工总厂 | Preparation of chromium anhydride |
| CN101456588A (en) * | 2009-01-05 | 2009-06-17 | 中南大学 | Process for preparing chromic oxide by hydrothermal reducing sodium chromate or sodium acid chromate |
| CN102627326A (en) * | 2012-04-27 | 2012-08-08 | 甘肃锦世化工有限责任公司 | Method for producing hydrated chromium oxide green |
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2016
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| CN1410357A (en) * | 2001-10-10 | 2003-04-16 | 中国科学院过程工程研究所 | Method of preparing chromium oxide using wet reducing potassium bichromate or sodium bichromate |
| CN1424258A (en) * | 2003-01-09 | 2003-06-18 | 济南裕兴化工总厂 | Preparation of chromium anhydride |
| CN101456588A (en) * | 2009-01-05 | 2009-06-17 | 中南大学 | Process for preparing chromic oxide by hydrothermal reducing sodium chromate or sodium acid chromate |
| CN102627326A (en) * | 2012-04-27 | 2012-08-08 | 甘肃锦世化工有限责任公司 | Method for producing hydrated chromium oxide green |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018177222A1 (en) * | 2017-03-27 | 2018-10-04 | 福建欣宇卫浴科技股份有限公司 | System and process for treating for wastewater containing chromium |
| CN107934993A (en) * | 2017-11-13 | 2018-04-20 | 陕西省商南县东正化工有限责任公司 | A kind of method for preparing anhydrous sodium sulfate using saltcake containing chromium |
| CN108862385A (en) * | 2018-09-10 | 2018-11-23 | 四川省银河化学股份有限公司 | The control method of partial size in a kind of production of chrome oxide green |
| CN109211718A (en) * | 2018-10-26 | 2019-01-15 | 湖北振华化学股份有限公司 | K in potassium bichromate production2The measuring method of O content |
| CN109211718B (en) * | 2018-10-26 | 2021-03-19 | 湖北振华化学股份有限公司 | K in potassium dichromate production2Method for measuring O content |
| CN110156122A (en) * | 2018-11-02 | 2019-08-23 | 福建省隆辉环保工程有限公司 | Electroplating concentrated control zone sewage chromium mud recovery method |
| CN110407253A (en) * | 2019-07-08 | 2019-11-05 | 重庆理工大学 | A kind of method of barium chromate preparation chrome oxide green |
| CN114715939A (en) * | 2021-01-06 | 2022-07-08 | 中国科学院青海盐湖研究所 | Nano chromium sesquioxide and preparation method thereof |
| CN115069234A (en) * | 2022-06-29 | 2022-09-20 | 华南理工大学 | Method for preparing hollow CrO simultaneously by detoxication and purification of chromium-containing waste salt x /Al 2 O 3 Method for preparing catalyst and its application |
| CN115069234B (en) * | 2022-06-29 | 2023-09-29 | 华南理工大学 | Chromium-containing waste salt detoxication and purification and simultaneous preparation of hollow CrO x /Al 2 O 3 Method for preparing catalyst and application thereof |
| CN115477327A (en) * | 2022-09-23 | 2022-12-16 | 绵阳光达环保科技有限责任公司 | Production process for producing hydroxyl chromic oxide by reducing sodium chromate with ethanol or methanol |
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