CN111943267A - Method for preparing chromium sesquioxide from vitamin K3 residual liquid - Google Patents
Method for preparing chromium sesquioxide from vitamin K3 residual liquid Download PDFInfo
- Publication number
- CN111943267A CN111943267A CN202010851085.XA CN202010851085A CN111943267A CN 111943267 A CN111943267 A CN 111943267A CN 202010851085 A CN202010851085 A CN 202010851085A CN 111943267 A CN111943267 A CN 111943267A
- Authority
- CN
- China
- Prior art keywords
- chromium
- solution
- chromate
- hexavalent chromium
- vitamin
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- 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
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Treatment Of Water By Oxidation Or Reduction (AREA)
- Chemical Treatment Of Metals (AREA)
Abstract
The invention provides a method for preparing chromium sesquioxide from vitamin K3 residual liquid, which comprises the following steps: mixing the residual vitamin K3 liquid with a hexavalent chromium salt solution and a reducing agent, and reacting to obtain a reducing solution; mixing the obtained reduction solution with a hexavalent chromium salt solution, heating, and adjusting the pH value to generate chromium chromate precipitate; and calcining the chromium chromate precipitate to obtain chromium sesquioxide. According to the method, chromium in the vitamin K3 residual liquid is sequentially reduced, precipitated and calcined to prepare chromium sesquioxide, hexavalent chromium salt is added in the reduction and precipitation stages, the hexavalent chromium salt is used for consuming acid, and the hexavalent chromium salt is used for forming chromium chromate precipitate, so that a new chromium recovery way is provided, and the chromium recovery rate is high; the method is simple and convenient to operate, can greatly reduce the consumption of the alkali liquor, reduces the recovery cost of chromium, and has wide application prospect.
Description
Technical Field
The invention belongs to the technical field of waste liquid recycling, and relates to a method for preparing chromium sesquioxide from vitamin K3 residual liquid.
Background
Along with the development of economy, the demand of China on chromium resources is increasing day by day, besides the exploitation and utilization of chromium-containing ores, the recovery of chromium-containing solution is also one of important ways, and because hexavalent chromium in chromium-containing solution has great harm to the environment and the health of human bodies, the recovery and utilization of hexavalent chromium are necessary. Vitamin K3 is also called menadione, 2-methyl-1, 4-naphthoquinone or sodium bisulfite menadione, belongs to procoagulant drug, and can be used for treating hemorrhagic diseases caused by vitamin K3 deficiency. When vitamin K3 is produced, a chromium-containing waste liquid is generated, which is called vitamin K3 residual liquid, and the residual liquid comprises chromium sulfate, sodium dichromate, sulfuric acid, sodium sulfate, a small amount of organic matters and the like.
At present, there are two general schemes for recovering chromium from vitamin K3 raffinate: one is to prepare chromium powder, which belongs to a mature process in the industry, and is not an optimal recovery scheme because the production is limited due to the problems of high yield, low product profit rate, saturated market and the like; the other recovery scheme is to prepare chromium sesquioxide, the chromium sesquioxide product has wide application, can be widely applied to the fields of metallurgy, pigment, refractory materials and the like, and has wider market and economic value compared with chromium powder.
CN 103613133A discloses a method for treating naphthoquinone production waste liquid containing hexavalent chromium and vitamin K3 production waste water and co-producing chromium oxide green, which comprises the following steps: a) carrying out liquid phase reaction on the naphthoquinone production waste liquid and vitamin K3 production waste water, wherein the naphthoquinone production waste liquid is equivalent to the required amount for complete reduction and is used in excess; b) adding a reducing agent to the reaction mixture to reduce the residual hexavalent chromium; c) regulating the pH value to separate out chromium hydroxide, and converting the separated chromium hydroxide into chromium oxide green; according to the method, the chromic oxide is prepared from the intermediate product of the chromium hydroxide, a large amount of sodium hydroxide, sodium carbonate or a mixture of sodium hydroxide and sodium carbonate is required in the preparation process, the economic cost is high, a large amount of sodium sulfate is generated in the later stage, the utilization value is low, and the efficient utilization of the vitamin K3 residual liquid is not realized.
CN 106241874A discloses a method for preparing chromium oxide green by utilizing residual liquid obtained by naphthoquinone production, which comprises the following steps: 1) adding a certain amount of reducing agent into the residual liquid for producing the vitamin K3 to convert Cr (VI) into Cr (III) to obtain mixed liquid; 2) adding a calcium-containing compound into the reduced mixed solution, and adjusting the pH of the mixed solution to a certain value; 3) filtering the mixture obtained in the step 2), adding hydroxide or carbonate into the filtrate, adjusting the pH value of the solution to a certain value, filtering, washing a filter cake, and calcining to obtain the chromium oxide green. The method firstly selects a calcium-containing compound to neutralize acid in the waste liquid, and then adds an alkaline substance to generate chromium hydroxide so as to prepare chromium sesquioxide. CN 107720824A discloses a process for preparing chromium green by a K3 residual liquid sulfur method, which is divided into two sections, but chromium sesquioxide is prepared by an intermediate product chromium hydroxide, so the problems of overlarge alkali liquor consumption and high cost exist.
In conclusion, it is an urgent need to provide a new method for recovering and preparing chromium sesquioxide from vitamin K3 raffinate, which can reduce the usage amount of alkaline solution and simplify the recovery process to save economic cost.
Disclosure of Invention
In view of the problems in the prior art, the invention aims to provide a method for preparing chromium sesquioxide from vitamin K3 raffinate, the method prepares chromium sesquioxide by sequentially reducing, precipitating and calcining chromium in vitamin K3 raffinate, and hexavalent chromium salt is added in both the reduction stage and the precipitation stage, wherein the hexavalent chromium salt is used for consuming acid, and the hexavalent chromium salt is used for forming chromium chromate precipitate, so that a novel chromium recovery way is provided, the operation is simple and convenient, the consumption of alkali liquor is greatly reduced, and the recovery cost is reduced.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides a method for preparing chromium sesquioxide from vitamin K3 residual liquid, which comprises the following steps:
(1) mixing the residual vitamin K3 liquid with a hexavalent chromium salt solution and a reducing agent, and reacting to obtain a reducing solution;
(2) mixing the reducing solution obtained in the step (1) with a hexavalent chromium salt solution, heating, and adjusting the pH value to generate chromium chromate precipitate;
(3) and (3) calcining the chromium chromate precipitate obtained in the step (2) to obtain chromium sesquioxide.
In the method for recovering chromium from the vitamin K3 residual liquid, hexavalent chromium is reduced firstly, and because of the characteristics of the residual liquid, the acid content is higher, and hydrogen ions are consumed while hexavalent chromium is reduced, hexavalent chromium salt is added until the hydrogen ions are fully consumed, and complete reduction of hexavalent chromium is also ensured; in the precipitation stage, hexavalent chromium salt is added and the pH value is controlled, so that chromium chromate precipitation can be formed between the hexavalent chromium salt and the chromium salt, and the amount of the consumed pH regulator is greatly reduced; the method provides a new chromium recovery way for preparing chromium sesquioxide by chromic chromate, and has the advantages of simple operation and low cost.
The following technical solutions are preferred technical solutions of the present invention, but not limited to the technical solutions provided by the present invention, and technical objects and advantageous effects of the present invention can be better achieved and achieved by the following technical solutions.
In a preferred embodiment of the invention, the concentration of hexavalent chromium in the vitamin K3 residual liquid in the step (1) is 62-66 g/L, such as 62g/L, 63g/L, 64g/L, 65g/L or 66g/L, but is not limited to the values listed, and other values not listed in the range of the values are also applicable; the sulfuric acid concentration is 100 to 135g/L, for example, 100g/L, 105g/L, 110g/L, 115g/L, 120g/L, 125g/L, 130g/L or 135g/L, but is not limited to the recited values, and other values not recited within the range of the values are also applicable.
Preferably, the hexavalent chromium salt solution of step (1) includes any one of a sodium chromate solution, a sodium dichromate solution, a potassium chromate solution, or a potassium dichromate solution, or a combination of at least two thereof, which are typical but non-limiting examples of the combination: a combination of a sodium chromate solution and a sodium dichromate solution, a combination of a potassium chromate solution and a potassium dichromate solution, a combination of a sodium chromate solution and a potassium chromate solution, a combination of a sodium chromate solution, a sodium dichromate solution, or a potassium chromate solution, or the like; when a plurality of solution combinations are selected, solution combinations of the same cation are preferably selected.
Preferably, the chromium content of the hexavalent chromium salt solution in the step (1) is 24 to 48 wt% of the hexavalent chromium content of the vitamin K3 raffinate, such as 24 wt%, 27 wt%, 30 wt%, 33 wt%, 36 wt%, 39 wt%, 42 wt%, 45 wt%, or 48 wt%, but not limited to the recited values, and other non-recited values within the range are also applicable.
As a preferred technical solution of the present invention, the reducing agent in step (1) comprises any one or a combination of at least two of glucose, sucrose, sulfite, pyrosulfite, or thiosulfate, and typical but non-limiting examples of the combination are: combinations of glucose and sucrose, sulfites and metabisulfites, sulfites and thiosulfates, sucrose, sulfites and metabisulfites, and the like.
Preferably, the amount of the reducing agent in step (1) is 1.05 to 1.1 times, for example, 1.05 times, 1.06 times, 1.07 times, 1.08 times, 1.09 times or 1.1 times, etc., of the theoretical amount of hexavalent chromium, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.
In the invention, the reducing agent is used for reducing the hexavalent chromium in the provitamin K3 residual liquid and reducing the chromium in the added hexavalent chromium salt solution to fully consume hydrogen ions, and the chromium can be recovered through subsequent steps without waste.
As a preferred technical scheme of the invention, hexavalent chromium is reduced to trivalent chromium in the reaction process of the step (1).
Preferably, the temperature of the reaction in step (1) is 70 to 90 ℃, for example 70 ℃, 75 ℃, 80 ℃, 85 ℃ or 90 ℃, but not limited to the recited values, and other values not recited in the range of the values are also applicable.
Preferably, the reaction time in step (1) is 10-60 min, such as 10min, 20min, 30min, 40min, 50min or 60min, but not limited to the recited values, and other values not recited in the range of the values are also applicable.
Preferably, the pH of the reducing solution in step (1) is 1.5-2, such as 1.5, 1.6, 1.7, 1.8, 1.9 or 2, but not limited to the recited values, and other values not recited in the range of values are also applicable.
In the invention, the reduction reaction in the step (1) basically finishes the consumption of the sulfuric acid, and the solution is acidic and mainly caused by the hydrolysis of chromium sulfate.
As a preferred embodiment of the present invention, the hexavalent chromium salt solution of step (2) includes any one of a sodium chromate solution, a sodium dichromate solution, a potassium chromate solution, or a potassium dichromate solution, or a combination of at least two thereof, and the combination is exemplified by, typically but not limited to: a combination of a sodium chromate solution and a sodium dichromate solution, a combination of a potassium chromate solution and a potassium dichromate solution, a combination of a sodium chromate solution and a potassium chromate solution, a combination of a sodium chromate solution, a sodium dichromate solution, or a potassium chromate solution, or the like; when a plurality of solution combinations are selected, a combination of solutions of the same cation is preferably selected, and a hexavalent chromium salt solution of the same cation as in step (1) is preferably selected.
Preferably, the chromium content in the hexavalent chromium salt solution in the step (2) is 22 to 28 wt% of the total chromium content in the vitamin K3 raffinate treated in the step (1), such as 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt% or 28 wt%, but not limited to the enumerated values, and other non-enumerated values in the range of the enumerated values are also applicable.
In the present invention, the amount of hexavalent chromium salt solution added is selected based mainly on: the amount of the hexavalent chromium salt solution added in the step (1) depends on the contents of sulfuric acid and hexavalent chromium in the initial reaction solution and the kind of the reducing agent, while the amount of the hexavalent chromium salt solution added in the step (2) depends on the total amount of trivalent chromium in the solution before the reaction, and since chromium chromate obtained in the actual production process is not the theoretical molar ratio of chromium of two valence states, the amount of the hexavalent chromium salt added is not a theoretical amount.
In a preferred embodiment of the present invention, the temperature raising in the step (2) is 70 to 95 ℃, for example, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃ or 95 ℃, but the temperature raising is not limited to the above-mentioned values, and other values not shown in the above-mentioned range are also applicable.
Preferably, the pH adjustment in step (2) is performed by using a pH regulator.
Preferably, the pH modifier comprises a carbonate and/or caustic, preferably sodium or potassium carbonate, caustic soda or potassium, or the like.
Preferably, step (2) adjusts the pH to 4-5.5, such as 4, 4.2, 4.5, 4.8, 5, 5.2, or 5.5, but not limited to the recited values, and other values within this range are equally applicable, preferably 5-5.5.
In the invention, under the condition that hexavalent chromium and trivalent chromium ions coexist, the precipitate of chromium chromate can be generated by adjusting and controlling the pH value, so that chromium is separated from the solution, and chromium is recovered through an intermediate product of the chromium chromate to prepare chromium sesquioxide, belonging to a new chromium recovery way.
In a preferred embodiment of the present invention, the duration of the formation of the chromium chromate precipitate in step (2) is 1 to 3 hours, for example, 1 hour, 1.5 hours, 2 hours, 2.5 hours, or 3 hours, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.
Preferably, after the chromium chromate precipitate is generated in the step (2), solid-liquid separation is carried out, the obtained solid phase is washed and dried, and the obtained liquid phase is subjected to secondary reduction and evaporation processes to recover sulfate.
In the present invention, the main component of the liquid phase remaining after the solid-liquid separation is sulfate, but a small amount of hexavalent chromium salt and organic matter are contained, and the sulfate needs to be recovered through the steps of secondary reduction, evaporation, and the like.
Preferably, the drying temperature is 90 to 120 ℃, for example 90 ℃, 95 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃ or 120 ℃, but not limited to the recited values, and other values not recited in the range of the values are also applicable.
In a preferred embodiment of the present invention, the calcination temperature of the chromium chromate precipitate in step (3) is 900 to 1200 ℃, for example 900 ℃, 950 ℃, 1000 ℃, 1050 ℃, 1100 ℃, 1150 ℃ or 1200 ℃, but is not limited to the above-mentioned values, and other values not shown in the above-mentioned range are also applicable, preferably 1000 to 1100 ℃.
Preferably, the calcination time of the chromium chromate precipitation in the step (3) is 1-2 h, such as 1h, 1.2h, 1.4h, 1.5h, 1.6h, 1.8h or 2h, but not limited to the recited values, and other values not recited in the range of the values are also applicable.
As a preferable technical scheme of the invention, the calcined product in the step (3) is washed, dried and crushed in sequence.
Preferably, the purity of the chromium oxide in step (3) is 99% or more, such as 99%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, or 99.6%, etc., but is not limited to the recited values, and other values not recited in this range are also applicable.
As a preferred technical scheme of the invention, the method comprises the following steps:
(1) mixing the vitamin K3 residual liquid with a hexavalent chromium salt solution and a reducing agent, wherein the chromium content in the hexavalent chromium salt solution is 24-48 wt% of the hexavalent chromium content in the K3 residual liquid, the reducing agent comprises any one or a combination of at least two of glucose, sucrose, sulfite, pyrosulfite and thiosulfate, the using amount of the reducing agent is 1.05-1.1 times of the theoretical using amount, hexavalent chromium is reduced to trivalent chromium after reaction, the reaction temperature is 70-90 ℃, the reaction time is 10-60 min, and a reducing solution is obtained, and the pH value of the reducing solution is 1.5-2;
(2) mixing the reducing solution obtained in the step (1) with a hexavalent chromium salt solution, and then heating, wherein the chromium content in the hexavalent chromium salt solution is 22-28 wt% of the total chromium content in the K3 residual liquid treated in the step (1), the heating temperature is 70-95 ℃, a pH regulator is adopted to regulate the pH value to 4-5.5, a chromium chromate precipitate is generated, and the duration is 1-3 hours; after generating chromium chromate sediment, carrying out solid-liquid separation, washing and drying the obtained solid phase to obtain chromium chromate solid;
(3) and (3) calcining the chromium chromate solid obtained in the step (2), wherein the calcining temperature is 900-1200 ℃, the calcining time is 1-2 h, and the calcined product is sequentially washed, dried and crushed to obtain a chromium sesquioxide product.
Compared with the prior art, the invention has the following beneficial effects:
(1) the method prepares chromium sesquioxide by sequentially reducing, precipitating and calcining chromium in the vitamin K3 residual liquid, and hexavalent chromium salt is added in the reduction and precipitation stages, wherein the hexavalent chromium salt is used for consuming acid, and the hexavalent chromium salt is used for forming chromium chromate precipitate, so that a new chromium recovery way is provided, and the chromium recovery rate can reach more than 90%;
(2) the method is simple and convenient to operate, can greatly reduce the consumption of the alkali liquor, reduces the recovery cost of chromium, and has wide application prospect.
Detailed Description
In order to better illustrate the present invention and facilitate the understanding of the technical solutions of the present invention, the present invention is further described in detail below. However, the following examples are only simple examples of the present invention and do not represent or limit the scope of the present invention, which is defined by the claims.
The invention provides, in part, a process for producing chromium trioxide from vitamin K3 raffinate, the process comprising the steps of:
(1) mixing the residual vitamin K3 liquid with a hexavalent chromium salt solution and a reducing agent, and reacting to obtain a reducing solution;
(2) mixing the reducing solution obtained in the step (1) with a hexavalent chromium salt solution, heating, and adjusting the pH value to generate chromium chromate precipitate;
(3) and (3) calcining the chromium chromate precipitate obtained in the step (2) to obtain chromium sesquioxide.
The following are typical but non-limiting examples of the invention:
example 1:
this example provides a process for preparing chromium oxide from vitamin K3 raffinate, which contains hexavalent chromium 64.29g/L, trivalent chromium 146.36g/L (all as Na)2Cr2O7·2H2Calculated as O), 130.67g/L sulfuric acid, the process comprising the steps of:
(1) mixing the vitamin K3 residual liquid with a hexavalent chromium salt solution and a reducing agent, wherein the hexavalent chromium salt solution is a sodium dichromate solution, the chromium content is 42 wt% of the hexavalent chromium content in the K3 residual liquid, the reducing agent is glucose, the dosage of the glucose is 1.05 times of the theoretical dosage, the hexavalent chromium is reduced to trivalent chromium after reaction, the reaction temperature is 90 ℃, the reaction time is 60min, and a reducing solution is obtained, and the pH value of the reducing solution is 2;
(2) mixing the reducing solution obtained in the step (1) with a hexavalent chromium salt solution, heating, wherein the hexavalent chromium salt solution is a sodium chromate solution, the chromium content is 25 wt% of the chromium content in the K3 residual liquid treated in the step (1), the heating temperature is 90 ℃, the pH value is adjusted to 4.5 by using sodium hydroxide, the temperature is kept for 2 hours, filtering is carried out, a chromium chromate precipitate and a filtrate are obtained, the precipitate is washed until no sulfate radical is contained in washing water, and the chromium chromate solid is obtained by drying at 105 ℃;
(3) and (3) calcining the chromium chromate solid obtained in the step (2), wherein the calcining temperature is 1000 ℃, the calcining time is 1h, and the calcined product is sequentially washed, dried and crushed to obtain a chromium sesquioxide product.
In this example, the vitamin K3 raffinate was treated as described above, and the recovery rate of chromium was up to 90.69%, and the purity of the obtained chromium sesquioxide product was up to 99.32%.
Example 2:
this example provides a process for preparing chromium oxide from vitamin K3 raffinate, which contains hexavalent chromium 62.48g/L and trivalent chromium 143.35g/L (both expressed as Na)2Cr2O7·2H2Calculated as O), 132.43g/L sulfuric acid, the process comprising the steps of:
(1) mixing the vitamin K3 residual liquid with a hexavalent chromium salt solution and a reducing agent, wherein the hexavalent chromium salt solution is a sodium chromate solution, the chromium content is 48 wt% of the hexavalent chromium content in the K3 residual liquid, the reducing agent is sodium sulfite, the using amount of the sodium sulfite is 1.1 times of the theoretical using amount, the hexavalent chromium is reduced to trivalent chromium after reaction, the reaction temperature is 70 ℃, the reaction time is 15min, and a reducing solution is obtained, and the pH value of the reducing solution is 1.5;
(2) mixing the reducing solution obtained in the step (1) with a hexavalent chromium salt solution, heating, wherein the hexavalent chromium salt solution is a sodium chromate solution, the chromium content is 22 wt% of the chromium content in the K3 residual liquid treated in the step (1), the heating temperature is 95 ℃, the pH value is adjusted to 5.5 by using sodium carbonate, the temperature is kept for 1h, filtering is carried out, a chromium chromate precipitate and a filtrate are obtained, the precipitate is washed until no sulfate radical is contained in washing water, and the chromium chromate solid is obtained by drying at 90 ℃;
(3) and (3) calcining the chromium chromate solid obtained in the step (2), wherein the calcining temperature is 900 ℃, the calcining time is 2 hours, and the calcined product is sequentially washed, dried and crushed to obtain a chromium sesquioxide product.
In this example, the vitamin K3 raffinate was treated as described above, and the recovery rate of chromium was 92.89%, and the purity of the obtained chromium sesquioxide product was 99.28%.
Example 3:
this example provides a process for preparing chromium oxide from vitamin K3 raffinate, which contains hexavalent chromium 62.67g/L and trivalent chromium 154.32g/L (both expressed as Na)2Cr2O7·2H2Calculated as O), sulfuric acid 100.11g/L, the process comprising the steps of:
(1) mixing the vitamin K3 residual liquid with a hexavalent chromium salt solution and a reducing agent, wherein the hexavalent chromium salt solution is a potassium chromate solution, the chromium content is 25 wt% of the hexavalent chromium content in the K3 residual liquid, the reducing agent is sucrose, the dosage of the sucrose is 1.08 times of the theoretical dosage, the hexavalent chromium is reduced to trivalent chromium after reaction, the reaction temperature is 80 ℃, the reaction time is 30min, and a reducing solution is obtained, and the pH value of the reducing solution is 1.8;
(2) mixing the reducing solution obtained in the step (1) with a hexavalent chromium salt solution, and then heating, wherein the hexavalent chromium salt solution is a potassium chromate solution, the chromium content is 28 wt% of the chromium content in the K3 residual liquid treated in the step (1), the heating temperature is 80 ℃, the pH value is adjusted to 4 by using potassium carbonate, the temperature is kept for 3 hours, then filtering is carried out, a chromium chromate precipitate and a filtrate are obtained, the precipitate is washed until no sulfate radical is contained in washing water, and the chromium chromate solid is obtained by drying at 120 ℃;
(3) and (3) calcining the chromium chromate solid obtained in the step (2) at the calcining temperature of 1100 ℃ for 1.2h, and washing, drying and crushing calcined products in sequence to obtain a chromium sesquioxide product.
In this example, the vitamin K3 raffinate was treated as described above, and the recovery rate of chromium was 95.98%, and the purity of the obtained chromium sesquioxide product was 99.45%.
Example 4:
this example provides a process for preparing chromium oxide from vitamin K3 raffinate, which contains hexavalent chromium 65.22g/L and trivalent chromium 143.36g/L (both expressed as Na)2Cr2O7·2H2Calculated as O), 107.33g/L sulfuric acid, the process comprising the steps of:
(1) mixing the vitamin K3 residual liquid with a hexavalent chromium salt solution and a reducing agent, wherein the hexavalent chromium salt solution is a potassium dichromate solution, the chromium content is 36 wt% of the hexavalent chromium content in the K3 residual liquid, the reducing agent is potassium metabisulfite, the using amount of the potassium metabisulfite is 1.06 times of the theoretical using amount, the hexavalent chromium is reduced to trivalent chromium after reaction, the reaction temperature is 75 ℃, the reaction time is 45min, and a reducing solution is obtained, and the pH value of the reducing solution is 1.6;
(2) mixing the reducing solution obtained in the step (1) with a hexavalent chromium salt solution, and then heating, wherein the hexavalent chromium salt solution is a potassium dichromate solution, the chromium content is 24 wt% of the chromium content in the K3 residual liquid treated in the step (1), the heating temperature is 70 ℃, the pH value is adjusted to 5 by adopting potassium hydroxide, the temperature is kept for 1.5h, then filtering is carried out, chromium chromate precipitate and filtrate are obtained, the precipitate is washed until no sulfate radical is contained in washing water, and the precipitate is dried at the temperature of 110 ℃ to obtain chromium chromate solid;
(3) and (3) calcining the chromium chromate solid obtained in the step (2) at 1200 ℃ for 1.5h, and washing, drying and crushing calcined products in sequence to obtain a chromium sesquioxide product.
In this example, the vitamin K3 raffinate was treated as described above, and the recovery rate of chromium was 93.38%, and the purity of the obtained chromium sesquioxide product was 99.52%.
Example 5:
this example provides a process for preparing chromium oxide from vitamin K3 raffinate, which contains hexavalent chromium 65.89g/L and trivalent chromium 132.97g/L (both expressed as Na)2Cr2O7·2H2Calculated as O), 134.78g/L sulfuric acid, the process comprising the steps of:
(1) mixing the vitamin K3 residual liquid with a hexavalent chromium salt solution and a reducing agent, wherein the hexavalent chromium salt solution is a sodium chromate solution, the chromium content is 46 wt% of the hexavalent chromium content in the K3 residual liquid, the reducing agent is sodium thiosulfate, the using amount of the sodium thiosulfate is 1.05 times of the theoretical using amount, the hexavalent chromium is reduced to trivalent chromium after reaction, the reaction temperature is 85 ℃, the reaction time is 20min, and a reducing solution is obtained, and the pH value of the reducing solution is 2;
(2) mixing the reducing solution obtained in the step (1) with a hexavalent chromium salt solution, heating, wherein the hexavalent chromium salt solution is a sodium chromate solution, the chromium content is 22 wt% of the chromium content in the K3 residual liquid treated in the step (1), the heating temperature is 85 ℃, the pH value is adjusted to 4.8 by using sodium hydroxide, filtering is carried out after heat preservation is carried out for 2.5 hours, chromium chromate precipitate and filtrate are obtained, the precipitate is washed until no sulfate radical is contained in washing water, and drying is carried out at the temperature of 100 ℃ to obtain chromium chromate solid;
(3) and (3) calcining the chromium chromate solid obtained in the step (2) at 1050 ℃ for 1.8h, and washing, drying and crushing calcined products in sequence to obtain a chromium sesquioxide product.
In this example, the vitamin K3 raffinate was treated as described above, and the recovery rate of chromium was 93.15%, and the purity of the obtained chromium sesquioxide product was 99.34%.
Comparative example 1:
this comparative example provides a process for preparing chromium trioxide from vitamin K3 raffinate, which is referenced to the process in example 1, except that: in the steps (1) and (2), hexavalent chromium salt solution is not added.
In the comparative example, because no hexavalent chromium-containing solution is added in the step (1), a large amount of hydrogen ions still exist in the vitamin K3 residual liquid after the hexavalent chromium is reduced, a large amount of alkali liquor needs to be added in the step (2) for neutralization, and no hexavalent chromium-containing solution is added, so that the trivalent chromium in the solution needs to be adjusted to the pH of about 7 to generate chromium hydroxide precipitate, the consumption of the alkali liquor is further increased, and the consumption is increased by 92% compared with that in the example 1.
It can be seen from the above examples and comparative examples that the process of the present invention prepares chromium sesquioxide by sequentially reducing, precipitating and calcining chromium in vitamin K3 raffinate, and hexavalent chromium salts are added in both the reduction and precipitation stages, the former being used for consuming acid and the latter being used for forming chromium chromate precipitate, providing a new chromium recovery route, and the chromium recovery rate can reach more than 90%; the method is simple and convenient to operate, can greatly reduce the consumption of the alkali liquor, reduces the recovery cost of chromium, and has wide application prospect.
The applicant states that the present invention is illustrated in detail by the above examples, but the present invention is not limited to the above detailed methods, i.e. it is not meant that the present invention must rely on the above detailed methods for its implementation. It will be apparent to those skilled in the art that any modification, equivalent substitution of the process of the invention and addition of ancillary operations, selection of specific means, etc., of the present invention are within the scope and disclosure of the invention.
Claims (10)
1. A process for preparing chromium trioxide from vitamin K3 raffinate, said process comprising the steps of:
(1) mixing the residual vitamin K3 liquid with a hexavalent chromium salt solution and a reducing agent, and reacting to obtain a reducing solution;
(2) mixing the reducing solution obtained in the step (1) with a hexavalent chromium salt solution, heating, and adjusting the pH value to generate chromium chromate precipitate;
(3) and (3) calcining the chromium chromate precipitate obtained in the step (2) to obtain chromium sesquioxide.
2. The method according to claim 1, wherein the concentration of hexavalent chromium in the vitamin K3 raffinate in the step (1) is 62-66 g/L, and the concentration of sulfuric acid is 100-135 g/L;
preferably, the hexavalent chromium salt solution of step (1) includes any one of a sodium chromate solution, a sodium dichromate solution, a potassium chromate solution, or a potassium dichromate solution or a combination of at least two thereof;
preferably, the content of chromium in the hexavalent chromium salt solution in the step (1) is 24-48 wt% of the content of hexavalent chromium in the vitamin K3 residual liquid.
3. The method of claim 1 or 2, wherein the reducing agent of step (1) comprises any one or a combination of at least two of glucose, sucrose, sulfite, pyrosulfite, or thiosulfate;
preferably, the dosage of the reducing agent in the step (1) is 1.05-1.1 times of the theoretical dosage of the hexavalent chromium which is completely reduced to the trivalent chromium.
4. The process of any one of claims 1 to 3 wherein hexavalent chromium is reduced to trivalent chromium during the reaction of step (1);
preferably, the temperature of the reaction in the step (1) is 70-90 ℃;
preferably, the reaction time in the step (1) is 10-60 min;
preferably, the pH of the reducing solution in the step (1) is 1.5-2.
5. The process of any one of claims 1 to 4 wherein the hexavalent chromium salt solution of step (2) includes any one of a sodium chromate solution, a sodium dichromate solution, a potassium chromate solution, or a potassium dichromate solution, or a combination of at least two thereof;
preferably, the chromium content in the hexavalent chromium salt solution in the step (2) is 22-28 wt% of the total chromium content in the vitamin K3 residual liquid treated in the step (1).
6. The method according to any one of claims 1 to 5, wherein the temperature rise in the step (2) is 70 to 95 ℃;
preferably, the pH adjustment in the step (2) adopts a pH regulator;
preferably, the pH adjusting agent comprises a carbonate and/or a caustic;
preferably, the pH value is adjusted to 4-5.5, preferably 5-5.5 in the step (2).
7. The method according to any one of claims 1 to 6, wherein the duration of the formation of the chromium chromate precipitate in step (2) is 1 to 3 hours;
preferably, after the chromium chromate precipitate is generated in the step (2), solid-liquid separation is carried out, the obtained solid phase is washed and dried, and the obtained liquid phase is subjected to secondary reduction and evaporation processes to recover sulfate;
preferably, the drying temperature is 90-120 ℃.
8. The process according to any one of claims 1 to 7, wherein the calcination temperature of the chromium chromate precipitate in step (3) is 900 to 1200 ℃, preferably 1000 to 1100 ℃;
preferably, the calcination time of the chromium chromate precipitate in the step (3) is 1-2 h.
9. The method according to any one of claims 1 to 8, wherein the calcined product of step (3) is washed, dried and crushed in this order;
preferably, the purity of the chromic oxide in the step (3) reaches more than 99%.
10. Method according to any of claims 1-9, characterized in that the method comprises the steps of:
(1) mixing the vitamin K3 residual liquid with a hexavalent chromium salt solution and a reducing agent, wherein the chromium content in the hexavalent chromium salt solution is 24-48 wt% of the hexavalent chromium content in the K3 residual liquid, the reducing agent comprises any one or a combination of at least two of glucose, sucrose, sulfite, pyrosulfite and thiosulfate, the using amount of the reducing agent is 1.05-1.1 times of the theoretical using amount, hexavalent chromium is reduced to trivalent chromium after reaction, the reaction temperature is 70-90 ℃, the reaction time is 10-60 min, and a reducing solution is obtained, and the pH value of the reducing solution is 1.5-2;
(2) mixing the reducing solution obtained in the step (1) with a hexavalent chromium salt solution, and then heating, wherein the chromium content in the hexavalent chromium salt solution is 22-28 wt% of the total chromium content in the K3 residual liquid treated in the step (1), the heating temperature is 70-95 ℃, a pH regulator is adopted to regulate the pH value to 4-5.5, a chromium chromate precipitate is generated, and the duration is 1-3 hours; after generating chromium chromate sediment, carrying out solid-liquid separation, washing and drying the obtained solid phase to obtain chromium chromate solid;
(3) and (3) calcining the chromium chromate solid obtained in the step (2), wherein the calcining temperature is 900-1200 ℃, the calcining time is 1-2 h, and the calcined product is sequentially washed, dried and crushed to obtain a chromium sesquioxide product.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010851085.XA CN111943267A (en) | 2020-08-21 | 2020-08-21 | Method for preparing chromium sesquioxide from vitamin K3 residual liquid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010851085.XA CN111943267A (en) | 2020-08-21 | 2020-08-21 | Method for preparing chromium sesquioxide from vitamin K3 residual liquid |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111943267A true CN111943267A (en) | 2020-11-17 |
Family
ID=73359034
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010851085.XA Pending CN111943267A (en) | 2020-08-21 | 2020-08-21 | Method for preparing chromium sesquioxide from vitamin K3 residual liquid |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111943267A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113233507A (en) * | 2021-06-15 | 2021-08-10 | 湖北振华化学股份有限公司 | Method for preparing basic chromium sulfate from residual liquid in menadione production |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103613133A (en) * | 2013-12-17 | 2014-03-05 | 四川省银河化学股份有限公司 | Method for treating naphthoquinone production liquid waste containing hexavalent chromium and vitamin K3 production wastewater and co-producing chromium oxide green |
| CN111484079A (en) * | 2020-04-23 | 2020-08-04 | 成都铬科高化工技术有限责任公司 | Method for preparing chromium oxide green from chromium-containing waste liquid in naphthoquinone production |
-
2020
- 2020-08-21 CN CN202010851085.XA patent/CN111943267A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103613133A (en) * | 2013-12-17 | 2014-03-05 | 四川省银河化学股份有限公司 | Method for treating naphthoquinone production liquid waste containing hexavalent chromium and vitamin K3 production wastewater and co-producing chromium oxide green |
| CN111484079A (en) * | 2020-04-23 | 2020-08-04 | 成都铬科高化工技术有限责任公司 | Method for preparing chromium oxide green from chromium-containing waste liquid in naphthoquinone production |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113233507A (en) * | 2021-06-15 | 2021-08-10 | 湖北振华化学股份有限公司 | Method for preparing basic chromium sulfate from residual liquid in menadione production |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104118893B (en) | One utilizes titanium white waste acid manufacture level magnesium sulfate method | |
| CN107954474B (en) | Method for producing vanadium product and basic chromium sulfate by using vanadium-chromium solution | |
| CN104817105B (en) | Preparation method for treating titanium white by high zinc salt | |
| CN102616836B (en) | Preparation method of trivalent titanium solution | |
| CN109750169A (en) | The method of vanadium chromium is separated from vanadium chromium solution | |
| WO2018192441A1 (en) | Method for use in producing battery-grade vanadium oxide | |
| CN111484079B (en) | Method for preparing chromium oxide green from chromium-containing waste liquid in naphthoquinone production | |
| CN112978805A (en) | Comprehensive recovery method of titanium, iron and sulfate radicals in titanium white waste acid | |
| CN111943267A (en) | Method for preparing chromium sesquioxide from vitamin K3 residual liquid | |
| CN114231758B (en) | Vanadium pentoxide, and ammonium-free preparation method and application thereof | |
| CN104891576A (en) | Preparation method of manganese sulfate monohydrate | |
| CN112981100B (en) | Comprehensive utilization method of red mud by full wet method | |
| CN111115674A (en) | Ground underground salt, alkali and calcium circulation green production method | |
| CN107055612B (en) | A kind of method for preparing vanadium trioxide and chrome green using vanadium chromium reducing slag | |
| CN103910381B (en) | A kind of titanium liquid production method reducing acid consumption | |
| CN111847518A (en) | Efficient recycling method of silicomanganese slag | |
| CN116715270A (en) | Method for removing impurity ions in sodium dichromate mother solution by hydration of chromium oxide | |
| CN112390295A (en) | Method for utilizing artificial rutile mother liquor | |
| CN115108584B (en) | Method for efficiently preparing vanadium pentoxide and calcium carbonate by utilizing calcium vanadate | |
| CN110668497A (en) | Method for preparing vanadium and chromium products from vanadium-chromium-containing double salt and application of vanadium and chromium-containing double salt | |
| CN112875762B (en) | Method for preparing iron oxide red by using iron-containing pickling waste liquid | |
| CN112978796B (en) | Method for cleanly preparing vanadium pentoxide from sodium vanadate solution | |
| CN115417431A (en) | Method for extracting potassium in process of producing aluminum oxide by Bayer process | |
| CN114275811A (en) | Method for preparing electrolyte by purifying crude vanadium compound and electrolyte | |
| CN103950976A (en) | Method for preparing titanium dioxide by utilizing mixed alkali of sodium hydroxide and sodium nitrate |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |