CN1410357A - Method of preparing chromium oxide using wet reducing potassium bichromate or sodium bichromate - Google Patents
Method of preparing chromium oxide using wet reducing potassium bichromate or sodium bichromate Download PDFInfo
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Abstract
A process for preparing Cr2O3 by wet reduction of potassium (or sodium) bichromate includes such steps as preparing the aqueous solution of potassium (or sodium) bichromate, thermal pressure reaction on reducer to obtain hydrate of chromium oxide, filtering, drying filter cake, high-temp. calcining under protection of inertial gas, and cooling. Its advantages are short period, low cost and high output rate (more than 95%).
Description
Technical Field
The present invention relates to a method for producing an inorganic material, and more particularly to a method for producing chromium oxide by wet reduction of potassium dichromate or sodium dichromate.
Background
Chromium oxide, also known as chromium sesquioxide or chromium oxide green, is one of the leading products of the chromium salt industry, widely used as greenPigment, raw material for smelting metal chromium and catalyst in organic synthesis. The metal chromium is used for producing high-grade alloys, namely high-temperature-resistant, wear-resistant, corrosion-resistant and oxidation-resistant superalloys in the metallurgical industry, and is widely applied to manufacturing heating furnaces, gas turbines, aircraft engines, special military apparatuses, chemical devices and the like of atomic power stations; corrosion resistant aluminum alloys and high strength aluminum alloys produced from chromium and aluminum are useful for structural members of automobiles, containers, aircraft vehicles, ships, and the like. Thus, metallurgical grade Cr2O3The production of (a) is directly related to the development of the atomic energy industry, the aerospace industry, the defense and military industry and other industries.
At present, Cr is produced at home and abroad2O3The method mainly comprises ① chromic anhydride pyrolysis, ② potassium dichromate sulfur reduction roasting method, ③ sodium chromate sulfur wet reduction method and ④ sodium chromate and sodium sulfide wet reduction method, at present, the process commonly adopted by domestic manufacturers is that sodium dichromate is acidified by concentrated sulfuric acid to produce chromic anhydride, and then the chromic anhydride is roasted at high temperature to produce chromium oxide, the process has high production cost, generates a large amount of toxic waste water and chromium-containing smoke dust, and causes serious pollution and harm to the ecological environment and human health, and the process method using sulfur or sodium sulfide as a reducing agent has the advantages of easily obtained raw materials, longer production flow and large amount of SO generated in the production process2The smoke dust and the sulfur-containing waste and the by-products are difficult to separate and recycle, so that high-quality products are difficult to produce, and the obtained Cr2O3The sulfur content of (A) is high. For Cr in metallurgical industry2O3The requirement for a medium sulphur content is as low as possible, or even as low as possible, since the presence of sulphur is a serious hazard to the performance of the chromium-containing alloy.
Disclosure of Invention
The invention aims to overcome the defects of high production cost, environmental pollution, low product quality and the like in the existing production of chromium oxide, and provides a method for preparing chromium oxide by wet reduction of potassium dichromate or sodium dichromate, so that the production cost is reduced, the production process is simplified, the pollutant emission in any form is avoided, and the aim of controlling pollution from the source is fulfilled.
The invention discloses a method for preparing chromic oxide by wet reduction of potassium dichromate or sodium dichromate, which comprises the following steps:
(1) preparing aqueous solution of potassium dichromate or sodium dichromate with the concentration of 20-80 wt% respectively;
(2) under the condition of no inorganic acid as an acidifier, putting a potassium dichromate or sodium dichromate aqueous solution and a reducing agent into a hot-pressing reaction kettle for reaction to obtain chromium oxide hydrate slurry, wherein the using amount of the reducing agent is 100-150 mol% of that of the potassium dichromate or sodium dichromate according to a stoichiometric ratio;
(3) filtering and separating the chromium oxide hydrate slurry to obtain a chromium oxide hydrate filter cake and a filtrate;
(4) drying the filter cake at the temperature of 110-150 ℃;
(5) under the protection of inert gas, calcining the dried material at the high temperature of 700-1100 ℃, and cooling to the temperature below 100 ℃;
(6) and (3) washing the calcined material with water, and then drying the calcined material at the temperature of 110-150 ℃ to constant weight to finally obtain the chromium sesquioxide product.
According to the invention, the material washing liquid obtained in the step (6) is directly subjected to causticization treatment by lime milk to obtain KOH or NaOH.
The invention further obtains KHCO by evaporating, concentrating, carbonating, cooling, crystallizing and filtering the filtrate obtained in the step (3)3Or NaHCO3Crystals and crystallization mother liquor. And (3) returning the crystallization mother liquor to the step (1) for preparing a raw material liquid.
The reducing agent is sucrose, glucose, fructose or any mixture thereof.
The inert gas is N2、CO2Or CO.
The heating temperature in the step (2) is 110-140 ℃, and the reaction time is 10-60 minutes.
The drying time in the step (4) is 5-10 hours.
The calcining time in the step (5) is 1-5 hours.
The inorganic acid of the present invention is, for example, concentrated sulfuric acid, hydrochloric acid or nitric acid.
The concentration of the aqueous solution of potassium dichromate or sodium dichromate used in the present invention may be 20 to 80 wt%, preferably 30 to 50 wt%. Because the concentration is too low, the production amount of chromium oxide is limited, and the production cost is increased; if the concentration is too high, the slurry fluidity of the reduced chromium oxide hydrate is poor, and the subsequent operation is affected.
The reducing agent used in the present invention may be selected from low molecular weight saccharide compounds such as sucrose, glucose, fructose or their mixtures, and sucrose is considered to be most suitable in the present invention from the viewpoint of economy, raw material sources, reaction properties and the like. According to the stoichiometric ratio, the dosage of the reducing agent is 100-150 mol% of the potassium dichromate or the sodium dichromate, so as to ensure that the potassium dichromate or the sodium dichromate achieves higher conversion rate.
The aqueous solution of potassium dichromate or sodium dichromate and corresponding amount of saccharide compound are put into a hot-pressing reaction kettle, or solid potassium dichromate or sodium dichromate and water with corresponding amount are added into the hot-pressing reaction kettle together with the saccharide compound to be dissolved in the kettle. The solution is heated to 110-140 ℃, the saccharide compound and the potassium dichromate or sodium dichromate begin to react to generate chromium oxide hydrate, the reaction is exothermic, and the temperature of the system can be continuously raised by the heat released by the reaction, so as to maintain the reaction. The aqueous solutions of the alkali dichromates have a pH of 4.0 to 4.5, they react relatively rapidly with the reducing agent, with evolution of CO2The gas is dissolved in the reaction liquid to play a certain role in acidification, and an acidifying agent is not required to be added additionally.
The above reaction process carried out in a closed vessel can be represented by the following equation:
in addition to the above-mentioned main reactions, the sugar of the present invention will develop when the temperature of the system is raised to above 160 deg.CA series of caramelization is carried out to generate a dark brown or reddish brown dehydration condensation compound, namely caramel liquid; and alkaline substances such as K2CO3The presence of (b) has a strong catalytic effect on the process.
Filtering and separating the dark gray slurry obtained after the reaction to obtain a chromium oxide hydrate filter cake and a black red filtrate containing caramel. The obtained chromium oxide hydrate filter cake is not washed, and is directly calcined at high temperature under the protection of inert gas after being dried at the temperature of 110-1100 ℃; the calcination time is 1-5 hours. Calcined Cr2O3The Cr is obtained by three-time water washing, preferably three-stage countercurrent washing, and drying at the temperature of 110-150 ℃ to constant weight2O3And (5) producing the product.
The eluate in step (6) of the present invention is K2CO3Or Na2CO3The solution has low content of hexavalent chromium, and KOH or NaOH can be obtained by directly carrying out causticization treatment on the solution by lime milk.
The filtrate obtained by filtration and separation in the step (4) of the invention contains K2CO3And KHCO3Or containing Na2CO3And NaHCO3Caramel and a small amount of hexavalent chromium, in order to recover high-value potassium ions and recycle organic components and hexavalent chromium, the filtrate can be subjected to evaporation concentration, carbonation, cooling crystallization to obtain KHCO3Or NaHCO3And (3) returning the mother liquor of the crystals to the step (1) for preparing the raw material liquid.
The method has short process flow and simple operation, not only improves the product quality and yield, the yield reaches more than 95 percent, and the product can be used as a superior metallurgical raw material without sulfur; but also realizes the regeneration and cyclic utilization of potassium ions, reduces the production cost, does not discharge three wastes in the process flow, and achieves the clean production of chromium sesquioxide.
Detailed Description
Example 1
K with the preparation concentration of 40%2Cr2O7Dissolving in waterLiquid, will 416.67g K2Cr2O7The aqueous solution was mixed with 29.05g of sucrose (C)12H22O11) Adding the mixture into a hot-pressing reaction kettle, wherein the using amount of sucrose is 120 mol% of potassium dichromate according to the stoichiometric ratio, the oxidation-reduction reaction starts to occur when the mixture is heated to 120 ℃, the reaction is continuously carried out by depending on the self-released heat and pressure, the highest temperature reached by the system is 220 ℃, the highest pressure reached by the system is 2.5MPa, and the reaction time is about 15 minutes; the obtained slurry is easy to filter and separate. Separating the obtained filter cake, drying at 110 deg.C, and adding CO2Calcining at 800 ℃ for 2 hours at high temperature under the protection of gas; washing the calcined material with water for three times, and drying at 110 ℃ to obtain a product; causticizing the first-stage eluate with lime milk to obtain KOH; filtering and separating the slurry to obtain filtrate, evaporating and concentrating, carbonating, cooling and crystallizing, filtering and separating to obtain KHCO3Crystals and crystallization mother liquor. The result was that the total conversion of hexavalent chromium was 98.8%, Cr2O3The yield is 98.7 percent, and the recovery rate of potassium ions reaches more than 95 percent.
Example 2
K with the preparation concentration of 40%2Cr2O7Aqueous solution of 375.34gK2Cr2O7The aqueous solution was mixed with 26.85g of sucrose (C)12H22O11) And KHCO obtained in example 13Adding 52ml of crystallization mother liquor into a hot-pressing reaction kettle, wherein the total amount of sucrose in the system is 120 mol% of the total amount of potassium dichromate according to the stoichiometric ratio, heating to 140 ℃ to start redox reaction, continuing the reaction by means of self-released heat and pressure, the maximum temperature reached by the system is 210 ℃, the maximum pressure reached by the system is 2.3MPa, and the reaction time is about 17 min; the obtained slurry is easy to filter and separate. The filter cake obtained is separated, dried at 110 ℃ and then subjected to N2Carrying out high-temperature calcination under the protection of gas, wherein the calcination temperature is 900 ℃, and the calcination time is 2 h; washing the calcined material for three times, wherein the secondary eluate in example 1 is used for the first washing, the tertiary eluate in example 1 is used for the second washing, and distilled water is used for the third washing; washing and drying at 110 ℃ to obtain the product; lime treatment of the first-stage eluatePerforming emulsion causticization to obtain KOH; filtering and separating the slurry to obtain filtrate, evaporating and concentrating, carbonating, cooling and crystallizing, filtering and separating to obtain KHCO3Crystals and crystallization mother liquor. The result was that the total conversion of hexavalent chromium was 96.4%, Cr2O3The yield is 94.8 percent, and the recovery rate of potassium ions reaches more than 95 percent.
Example 3
K with the preparation concentration of 40%2Cr2O7Aqueous solution of 380.85gK2Cr2O7The aqueous solution was mixed with 27.42g of sucrose (C)12H22O11) And KHCO obtained in example 23Adding 45ml of crystallization mother liquor into a hot-pressing reaction kettle, wherein the total amount of sucrose in the system is 120 mol% of the total amount of potassium dichromate according to the stoichiometric ratio, heating to 130 ℃ to start redox reaction, continuing the reaction by means of self-released heat and pressure, the maximum temperature reached by the system is 210 ℃, the maximum pressure reached by the system is 2.4MPa, and the reaction time is about 15 min; the obtained slurry is easy to filter and separate. Separating the obtained filter cake, drying at 110 deg.C, and adding CO2Carrying out high-temperature calcination under the protection of gas, wherein the calcination temperature is 1000 ℃, and the calcination time is 1 h; washing the calcined material for three times, wherein the secondary eluate in the embodiment 2 is used for the first-stage washing, the tertiary eluate in the embodiment 2 is used for the second-stage washing, and distilled water is used for the third-stage washing; washing and drying at 110 ℃ to obtain the product; causticizing the first-stage eluate with lime milk to obtain KOH; filtering and separating the slurry to obtain filtrate, evaporating and concentrating, carbonating, cooling and crystallizing, filtering and separating to obtain KHCO3Crystals and crystallization mother liquor. As a result, the total conversion of hexavalent chromium was 97.4%, and Cr was found to be2O3The yield is 95.7%, and the recovery rate of potassium ions reaches more than 95%.
Example 4
K with the preparation concentration of 40%2Cr2O7Aqueous solution of 3373.67gK2Cr2O7The aqueous solution was mixed with 26.54g of sucrose (C)12H22O11) And KHCO obtained in example 33Adding 49ml of crystallization mother liquor into a hot-pressing reaction kettle, wherein,the total amount of sucrose in the system is 120 mol% of the total amount of potassium dichromate according to the stoichiometric ratio, oxidation-reduction reaction starts to occur when the system is heated to 120 ℃, the reaction is continued by means of self-released heat and pressure, the maximum temperature reached by the system is 210 ℃, the maximum pressure reached by the system is 2.3MPa, and the reaction time is about 16 min; the obtained slurry is easy to filter and separate. Separating the obtained filter cake, drying at 110 deg.C, and adding CO2Carrying out high-temperature calcination under the protection of gas, wherein the calcination temperature is 700 ℃, and the calcination time is 3 h; washing the calcined material for three times, wherein the secondary eluate in example 3 is used for the first washing, the tertiary eluate in example 3 is used for the second washing, and distilled water is used for the third washing; washing and drying at 110 ℃ to obtain the product; causticizing the first-stage eluate with lime milk to obtain KOH; filtering and separating the slurry to obtain filtrate, evaporating and concentrating, carbonating, cooling and crystallizing, filtering and separating to obtain KHCO3Crystals and crystallization mother liquor. As a result, the total conversion of hexavalent chromium was 97.2%, and Cr was found to be2O3The yield is 95.6%, and the recovery rate of potassium ions reaches more than 95%.
Example 5
K with the preparation concentration of 40%2Cr2O7Aqueous solution of 376.58gK2Cr2O7Aqueous solution with 26.45gSucrose (C)12H22O11) And KHCO obtained in example 43Adding 48ml of crystallization mother liquor into a hot-pressing reaction kettle, wherein the total amount of sucrose in the system is 120 mol% of the total amount of potassium dichromate according to the stoichiometric ratio, heating to 140 ℃ to start redox reaction, continuing the reaction by means of self-released heat and pressure, the highest temperature reached by the system is 220 ℃, the highest pressure reached by the system is 2.3MPa, and the reaction time is about 18 min; the obtained slurry is easy to filter and separate. Separating the obtained filter cake, drying at 110 deg.C, and adding CO2Carrying out high-temperature calcination under the protection of gas, wherein the calcination temperature is 800 ℃, and the calcination time is 3 h; washing the calcined material for three times, wherein the secondary eluate in example 4 is used for the first washing, the tertiary eluate in example 4 is used for the second washing, and distilled water is used for the third washing; washing and drying at 110 ℃ to obtain the product; first-stagewashingCausticizing the effluent by lime milk to obtain KOH; filtering and separating the slurry to obtain filtrate, evaporating and concentrating, carbonating, cooling and crystallizing, filtering and separating to obtain KHCO3Crystals and crystallization mother liquor. As a result, the total conversion of hexavalent chromium was 97.6%, and Cr was found to be2O3The yield is 95.4%, and the recovery rate of potassium ions reaches more than 95%.
Example 6
Na with the concentration of 30 percent is prepared2Cr2O7An aqueous solution of 357.14g Na2Cr2O7Aqueous solution, 11.36g sucrose (C)12H22O11) Adding 10.77g of glucose into a hot-pressing reaction kettle, wherein the molar ratio of the sucrose to the glucose is 1: 2, the total dosage of the sucrose and the glucose is 130 mol% of the potassium dichromate according to the stoichiometric ratio, the redox reaction starts to occur when the temperature is heated to 140 ℃, the reaction is continuously carried out by depending on the self-released heat and pressure, the highest temperature reached by the system is 230 ℃, the highest pressure reached by the system is 2.5MPa, and the reaction time is about 13 min; the obtained slurry is easy to filter and separate. Separating the obtained filter cake, drying at 110 deg.C, and adding CO2Carrying out high-temperature calcination under the protection of gas, wherein the calcination temperature is 800 ℃, and the calcination time is 3 h; washing the calcined material with water for three times, and drying at 110 ℃ to obtain a product; causticizing the primary eluate with lime milk to obtain NaOH; filtering and separating the slurry to obtain filtrate, evaporating and concentrating, carbonating, cooling and crystallizing, filtering and separating to obtain NaHCO3Crystals and crystallization mother liquor.The result was that the total conversion of hexavalent chromium was 99.1%, Cr2O3The yield is 98.6%, and the recovery rate of sodium ions reaches more than 95%.
Example 7
Na with the concentration of 30 percent is prepared2Cr2O7Aqueous solution, 305.7g Na2Cr2O7Aqueous solution, 8.4g sucrose (C)12H22O11) 8.2g glucose and NaHCO obtained in example 63Adding 62ml of crystallization mother liquor into a hot-pressing reaction kettle, wherein the molar ratio of sucrose to glucose is 1: 2, the total dosage of sucrose and glucose is 130 mol% of potassium dichromate according to the stoichiometric ratio, and the crystallization mother liquor begins to generate when being heated to 130 DEG CCarrying out oxidation-reduction reaction, wherein the reaction is continuously carried out by means of self-released heat and pressure, the highest temperature of the system is 220 ℃, the highest pressure of the system is 2.4MPa, and the reaction time is about 18 min; the obtained slurry is easy to filter and separate. Separating the obtained filter cake, drying at 110 deg.C, and adding CO2Carrying out high-temperature calcination under the protection of gas, wherein the calcination temperature is 800 ℃, and the calcination time is 3 h; the calcined material is washed for three times, wherein the secondary eluate in example 6 is used for the first washing, the tertiary eluate in example 6 is used for the second washing, and distilled water is used for the third washing; drying at 110 deg.C to obtain the product; causticizing the primary eluate with lime milk to obtain NaOH; filtering and separating the slurry to obtain filtrate, evaporating and concentrating, carbonating, cooling and crystallizing, filtering and separating to obtain NaHCO3Crystals and crystallization mother liquor. The resultwas that the total conversion of hexavalent chromium was 98.8%, Cr2O3The yield is 98.5%, and the recovery rate of sodium ions reaches more than 95%.
Example 8
Na with the concentration of 30 percent is prepared2Cr2O7An aqueous solution of 307.8g Na2Cr2O7Aqueous solution, 8.7g sucrose (C)12H22O11) 8.5g glucose and NaHCO obtained in example 73Adding 59ml of crystallization mother liquor into a hot-pressing reaction kettle, wherein the molar ratio of sucrose to glucose is 1: 2, the total dosage of sucrose and glucose is 130 mol% of potassium dichromate according to the stoichiometric ratio, heating to 120 ℃ and starting redox reaction, the reaction is continuously carried out by means of self-released heat and pressure, the highest temperature reached by the system is 230 ℃, the highest pressure reached by the system is 2.6MPa, and the reaction time is about 17 min; the obtained slurry is easy to filter and separate. Separating the obtained filter cake, drying at 110 deg.C, and adding CO2Carrying out high-temperature calcination under the protection of gas, wherein the calcination temperature is 1000 ℃, and the calcination time is 2 h; the calcined material is washed for three times, wherein the secondary eluate in example 7 is used for the first washing, the tertiary eluate in example 7 is used for the second washing, and distilled water is used for the third washing; drying at 110 deg.C to obtain the product; causticizing the primary eluate with lime milk to obtain NaOH; the slurry is filtered and separated to obtainEvaporating and concentrating the obtained filtrate, carbonating, cooling and crystallizing, filtering and separating to obtain NaHCO3Crystals and crystallization mother liquor. The result was that the total conversion of hexavalent chromium was 98.9%, Cr2O3The yield is 98.4%, and the recovery rate of sodium ions is more than 95%.
Claims (10)
1. A method for preparing chromic oxide by wet reduction of potassium dichromate or sodium dichromate is characterized in that: the method comprises the following steps:
(1) preparing aqueous solution of potassium dichromate or sodium dichromate with the concentration of 20-80 wt% respectively;
(2) under the condition of no inorganic acid as an acidifier, putting a potassium dichromate or sodium dichromate aqueous solution and a reducing agent into a hot-pressing reaction kettle for reaction to obtain chromium oxide hydrate slurry, wherein the using amount of the reducing agent is 100-150 mol% of that of the potassium dichromate or sodium dichromate according to a stoichiometric ratio;
(3) filtering and separating the chromium oxide hydrate slurry to obtain a chromium oxide hydrate filter cake and a filtrate;
(4) drying the filter cake at the temperature of 110-150 ℃;
(5) under the protection of inert gas, calcining the dried material at the high temperature of 700-1100 ℃, and cooling;
(6) and (3) washing the calcined material with water, and then drying the calcined material at the temperature of 110-150 ℃ to constant weight to finally obtain the chromium sesquioxide product.
2. The method of claim 1, further comprising: and (4) further causticizing the material washing liquid obtained in the step (6) directly by using lime milk to obtain KOH or NaOH.
3. The method of claim 1, further comprising: further carrying out evaporation concentration, carbonation, cooling crystallization and filtration separation on the filtrate obtained in the step (3) to obtain KHCO3Or NaHCO3Crystals and crystallization mother liquor.
4. The method of claim 3, wherein: and (3) returning the crystallization mother liquor to the step (1) for preparing a raw material liquid.
5. The method of claim 1, further comprising: the reducing agent is sucrose, glucose, fructose or any mixture thereof.
6. The method of claim 1, further comprising: the inert gas is N2、CO2Or CO.
7. The method of claim 1, further comprising: the heating temperature in the step (2) is 110-140 ℃.
8. The method of claim 1, further comprising: the reaction time of the step (2) is 10-60 minutes.
9. The method of claim 1, further comprising: the drying time in the step (4) is 5-10 hours.
10. The method of claim 1, further comprising: the calcining time in the step (5) is 1-5 hours.
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100375717C (en) * | 2005-08-02 | 2008-03-19 | 中国科学院过程工程研究所 | Method of preparing chromium oxide by reducing chromate with gaseous reducing agent at low temperature |
| 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 |
| CN103449521A (en) * | 2012-06-05 | 2013-12-18 | 中国科学院过程工程研究所 | Method for preparing chromium oxide green pigment through hydrated chromium oxide |
| CN104109767A (en) * | 2014-07-18 | 2014-10-22 | 中信锦州金属股份有限公司 | Production method of chromium sesquioxide |
| CN106277053A (en) * | 2016-07-25 | 2017-01-04 | 中国科学院过程工程研究所 | A kind of preparation method of chromium oxide |
| CN106365202A (en) * | 2016-08-29 | 2017-02-01 | 四川省银河化学股份有限公司 | Washing method for obtaining low-sulfur hydrated chromic oxide |
| CN109437384A (en) * | 2018-11-28 | 2019-03-08 | 大连理工大学 | Copper ion accelerates fructose-K2HPO4The method of product processing waste water containing chrome |
| CN114703363A (en) * | 2022-03-17 | 2022-07-05 | 四川省银河化学股份有限公司 | Method for separating vanadium and chromium in high-chromium system |
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2001
- 2001-10-10 CN CNB011415290A patent/CN1186264C/en not_active Expired - Fee Related
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100375717C (en) * | 2005-08-02 | 2008-03-19 | 中国科学院过程工程研究所 | Method of preparing chromium oxide by reducing chromate with gaseous reducing agent at low temperature |
| 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 |
| CN103449521A (en) * | 2012-06-05 | 2013-12-18 | 中国科学院过程工程研究所 | Method for preparing chromium oxide green pigment through hydrated chromium oxide |
| CN104109767A (en) * | 2014-07-18 | 2014-10-22 | 中信锦州金属股份有限公司 | Production method of chromium sesquioxide |
| CN106277053A (en) * | 2016-07-25 | 2017-01-04 | 中国科学院过程工程研究所 | A kind of preparation method of chromium oxide |
| CN106277053B (en) * | 2016-07-25 | 2019-01-08 | 中国科学院过程工程研究所 | A kind of preparation method of chromium oxide |
| CN106365202A (en) * | 2016-08-29 | 2017-02-01 | 四川省银河化学股份有限公司 | Washing method for obtaining low-sulfur hydrated chromic oxide |
| CN106365202B (en) * | 2016-08-29 | 2018-03-27 | 四川省银河化学股份有限公司 | Obtain the washing methods of low-sulfur hydrated chromium oxide |
| CN109437384A (en) * | 2018-11-28 | 2019-03-08 | 大连理工大学 | Copper ion accelerates fructose-K2HPO4The method of product processing waste water containing chrome |
| CN109437384B (en) * | 2018-11-28 | 2021-10-15 | 大连理工大学 | Copper ion accelerated fructose-K2HPO4Method for treating chromium-containing wastewater by using product |
| CN114703363A (en) * | 2022-03-17 | 2022-07-05 | 四川省银河化学股份有限公司 | Method for separating vanadium and chromium in high-chromium system |
| CN114703363B (en) * | 2022-03-17 | 2023-10-20 | 四川省银河化学股份有限公司 | Method for separating vanadium from chromium in high-chromium system |
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| CN1186264C (en) | 2005-01-26 |
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