CN107934993B - A method of anhydrous sodium sulfate is prepared using saltcake containing chromium - Google Patents

A method of anhydrous sodium sulfate is prepared using saltcake containing chromium Download PDF

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CN107934993B
CN107934993B CN201711117496.0A CN201711117496A CN107934993B CN 107934993 B CN107934993 B CN 107934993B CN 201711117496 A CN201711117496 A CN 201711117496A CN 107934993 B CN107934993 B CN 107934993B
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chromium
saltcake
sodium
aqueous solution
sodium sulfate
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CN201711117496.0A
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CN107934993A (en
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张国庆
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陕西省商南县东正化工有限责任公司
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    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01DCOMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
    • C01D5/00Sulfates or sulfites of sodium, potassium or alkali metals in general
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01GCOMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G37/00Compounds of chromium
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00Physical properties of inorganic compounds
    • C01P2006/60Optical properties, e.g. expressed in CIELAB-values
    • C01P2006/65Chroma (C*)
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00Physical properties of inorganic compounds
    • C01P2006/80Compositional purity
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00Physical properties of inorganic compounds
    • C01P2006/80Compositional purity
    • C01P2006/82Compositional purity water content

Abstract

The present invention relates to chemical industrial field more particularly to a kind of methods that the by-product saltcake containing chromium using in sodium dichromate production process prepares anhydrous sodium sulfate.The method of the present invention includes that will contain chromium saltcake to be dissolved in chromate waste water by a certain concentration, quantitative sodium thiosulfate is added, under the conditions of 0.1-1Mpa and 80-190 DEG C, Cr VI is promoted to be reduced into trivalent chromium, is precipitated in the form of being hydrated chrome green, and it is neutralized with a small amount of sulfuric acid, hydration chrome green is filtered out again, and removal of impurities decoloration evaporates and anhydrous slufuric acid sodium crystal is precipitated, continuous centrifugal separation, drying and other steps.The method of the present invention has the characteristics that simple process is easy, raw material is inexpensive, low energy consumption, increasingly automated, is suitble to large-scale production.Its quality of industrial anhydrous sodium sulfate product obtained meets I class product requirement in GB/T 6009-2014 industrial anhydrous sodium sulfate standard by the method for the invention.

Description

A method of anhydrous sodium sulfate is prepared using saltcake containing chromium
Technical field
The present invention relates to chemical industrial fields more particularly to a kind of by-product using in sodium dichromate production process to contain chromium The method that saltcake prepares anhydrous sodium sulfate.
Background technique
Before 2000, chromic salts enterprise, China sodium dichromate year production at 100,000 tons hereinafter, by-product awns containing chromium Nitre total amount is at 130,000 tons or so, though having tried to research and utilization saltcake containing chromium at that time prepares industrial anhydrous sodium sulfate, due to Sodium dichromate production scale is small, the by-product low output of saltcake containing chromium, using saltcake containing chromium prepare industrial anhydrous sodium sulfate at This is higher than the cost for directlying adopt natural mirabilite production anhydrous sodium sulfate, terminated such research later, then is contained using drying Chromium saltcake is as cement early strength agent, and since the Cr VI in saltcake containing chromium is not reduced, manufactured cement early strength agent can be to environment Generate pollution.Finally, most of chromic salts producer selection produces akali sulphide using saltcake containing chromium, because in the production process of akali sulphide In Cr VI in saltcake containing chromium can be reduced and release toxicity, but vulcanize the exhaust gas waste residue generated in alkali production process and still exist Pollute environment.
After 2000, the research recycled in relation to saltcake containing chromium gradually emerges in large numbers, and Sichuan An County milky way Jian Hua group has Limit company has developed a kind of method (CN200610000019.1) that potassium sulfate is prepared with saltcake containing chromium, but since energy consumption is excessively high, Production is difficult to realize serialization, causes potassium sulfate production cost high, can not form the market competitiveness.In recent years, Sichuan Li Xianrong, Hu Yihua of province milky way chemistry limited liability company et al. have developed a kind of by the purification anhydrous sodium sulphate of saltcake containing chromium again Method (CN201310533304.X), this method produce anhydrous sodium sulphate using magma method, but since there are magma package Cr VIs Problem causes Cr VI in the anhydrous sodium sulphate of production exceeded, sometime up to 100ppm;And since removal of impurities decoloration is not carried out in technique, Cause product whiteness that GB/T 6009-2014 industrial anhydrous sodium sulfate standard requirements are not achieved;In addition, what is used in this method goes back Former agent is sodium sulfite, and neutralizer is caustic soda, this two kinds of raw materials are prohibitively expensive for low-value product anhydrous sodium sulphate, is caused The anhydrous sodium sulphate high expensive of production, patented technology can not form reality potential productivity.
The purpose of the present invention is establish a set of by-product saltcake containing chromium using in sodium dichromate production process prepare it is anhydrous The technology path of sodium sulphate can be such that the saltcake containing chromium of by-product in chromic salts industry obtains adequately using present invention process method It recycles, avoids the dirt caused by environment in the treatment process of saltcake containing chromium while producing high added value anhydrous sodium sulfate product Dye is the efficient circular economy of Chrome Salt Industry Clean, improves the economic benefit of enterprise.In addition, due to present invention process letter Easy row, raw material is inexpensive, is conducive to promote, it is contemplated that have good market prospects.
Summary of the invention
In view of above-mentioned prior art situation, how the present inventor is for effectively to recycle sodium dichromate production By-product saltcake containing chromium in the process has made extensive and intensive studies, and to develop, a kind of simple process, low energy consumption, environment The technique of friendly recycling saltcake containing chromium.It is studied by repetition test, a set of new treatment process has been explored, by the way that chromium will be contained Saltcake is dissolved in a certain proportion of chromate waste water, controls certain concentration, and quantitative sodium thiosulfate is added, in 0.1-1Mpa and Under the conditions of 80-190 DEG C, Cr VI is promoted to be reduced into trivalent chromium, in the form of being hydrated chrome green be precipitated, and on a small quantity Sulfuric acid neutralizes, and is filtered to remove chromium hydroxide using the plate and frame filter press with filtration adjuvant, to guarantee not remain chromium ion in filtrate, Filtrate is decolourized by the high-efficiency and precision decolorization filtering machine filtering and impurity removing with adsorbent again, filtered sperm passes through machinery again Compression Evaporation device evaporative crystallization, it is dry through continuous drier after the anhydrous sodium sulfate after crystallization is separated by centrifuge continuous centrifugal It is dry to obtain finished product.
Main redox reaction is as follows:
8Na2CrO4+3Na2SO3+(5+4x)H2O→4Cr2O3·xH2O+6Na2SO4+10NaOH
In the methods of the invention, we use the reduction reaction under the conditions of specific acidity, and using gas conduct first Reducing agent, so as to avoid in magma method since magma wraps up caused by Cr VI the exceeded problem of Cr VI in product, greatly The content of 6-valence Cr ions in product is reduced greatly;Secondly, the hydro-thermal method reducing process that we use, eliminates and sulfuric acid step is added, And it is directly added into sodium thiosulfate, and a large amount of sulfuric acid and soda ash or caustic soda raw material are saved, not only cost of material is low, low energy consumption, and And it is conducive to automatic continuous production, production cost is greatly reduced, and cost, which is significantly lower than, produces anhydrous slufuric acid using natural mirabilite The prior art of sodium, and product impurity content is low, quality is better than the industrial anhydrous sodium sulfate that natural mirabilite produces;In addition, Removal of impurities decoloration process is introduced in the method for the present invention, using the high-efficiency and precision decolorization filtering machine with adsorbent to aqueous sodium sulfate Liquid carries out decolorization, improves the whiteness of product.
Through detecting, its quality of industrial anhydrous sodium sulfate product obtained meets GB/T6009-2014 by the method for the invention I class product requirement in industrial anhydrous sodium sulfate standard.
To sum up, the present invention is intended to provide it is a kind of easy-to-use, contain chromium using the by-product in sodium dichromate production process Saltcake prepares the process of anhydrous sodium sulfate.
The method that the present invention utilizes saltcake containing chromium to prepare anhydrous sodium sulfate, comprising the following steps:
(1) it chromium saltcake will be contained will be dissolved in chromate waste water and obtain the aqueous solution of saltcake containing chromium, and control the gained water of saltcake containing chromium The concentration of sodium sulphate is 15-32% in solution;
(2) quantitative sodium thiosulfate will be added in the aqueous solution of saltcake containing chromium, in 0.1-1Mpa and 80-190 DEG C of item Under part, Cr VI is promoted to be reduced into trivalent chromium, is precipitated in the form of being hydrated chrome green;
(3) aqueous solution of saltcake containing chromium after reduction is neutralized with industrial sulphuric acid, water soluble trivalent chromium is promoted to form hydroxide Chromium is precipitated;
(4) neutralizer that (3) step obtains is filtered in the plate and frame filter press with filtration adjuvant, filters out chromium hydroxide After obtain filtrate;
(5) removal of impurities decoloration is carried out using the filtrate that the high-efficiency and precision decolorization filtering machine with adsorbent obtains (4) step Obtain aqueous sodium persulfate solution;
(6) aqueous sodium persulfate solution after removal of impurities decoloration is evaporated using mechanical recompression evaporator, and anhydrous sodium sulfate is precipitated Crystal;
(7) gained anhydrous slufuric acid sodium crystal is delivered in continuous drier after carrying out continuous centrifugal separation with centrifuge and does It is dry, it is packed after dry and obtains anhydrous sodium sulfate product.
Preferably, chromate waste water described in the method for the present invention step (1) is the roasting generated in sodium dichromate production process Waste water, chromium-contained aluminum mud wash water, the wash water of saltcake containing chromium, chromic acid chromium wash water or the evaporation that technique leaching waste water, chromium slag filter out are cold containing chromium Condensate.
Preferably, in the method for the present invention step (2) in the aqueous solution of saltcake containing chromium Cr VI and sodium thiosulfate molal quantity it Than for 1 ﹕ 2.6-3.6.
Preferably, the control of neutralization reaction pH value described in the method for the present invention step (3) is 6.7-7, and temperature is controlled in 40- 100℃。
Preferably, filtration adjuvant described in the method for the present invention step (4) be any one of dolomite dust, marble powder or Two kinds of composition.
Further, the dolomite dust, marble powder fineness be 0.045-0.3mm.
Preferably, adsorbent described in the method for the present invention step (5) is one of diatomite, atlapulgite, active carbon Or it is a variety of.
Preferably, centrifuge described in the method for the present invention step (7) be Horizontal Centrifuge or horizontal spiral from Scheming, the continuous drier are continuous flow drying machine, continuous boiling drier, successive flash vaporization drying machine, continuous shaking stream Change bed dryer or continuous paddle-dryer.
It is further preferred that the method that the present invention utilizes saltcake containing chromium to prepare anhydrous sodium sulfate, comprising the following steps:
(1) it chromium saltcake will be contained will be dissolved in chromate waste water and obtain the aqueous solution of saltcake containing chromium, and control the gained water of saltcake containing chromium The concentration of sodium sulphate is 25% in solution;
(2) quantitative sodium thiosulfate, Cr VI and sodium thiosulfate mole will be added in the aqueous solution of saltcake containing chromium The ratio between number promotes Cr VI to be reduced into trivalent chromium for 1 ﹕ 2.7 under the conditions of 0.3Mpa and 130 DEG C, to be hydrated chrome green Form be precipitated;
(3) aqueous solution of saltcake containing chromium after reduction being neutralized with industrial sulphuric acid, pH value control is 7, and temperature is controlled at 95 DEG C, Promote water soluble trivalent chromium to form chromium hydroxide to be precipitated;
(4) neutralizer that (3) step obtains is filtered in the plate and frame filter press with filtration adjuvant, filtration adjuvant it is thin Degree is 0.1mm, obtains filtrate after filtering out chromium hydroxide;
(5) removal of impurities decoloration is carried out using the filtrate that the high-efficiency and precision decolorization filtering machine with adsorbent obtains (4) step Obtain aqueous sodium persulfate solution;
(6) aqueous sodium persulfate solution after removal of impurities decoloration is evaporated using mechanical recompression evaporator, and anhydrous sodium sulfate is precipitated Crystal;
(7) gained anhydrous slufuric acid sodium crystal is delivered in continuous drier after carrying out continuous centrifugal separation with centrifuge and does It is dry, it is packed after dry and obtains anhydrous sodium sulfate product
Using present invention process method, the saltcake containing chromium of by-product in chromic salts industry can be made adequately to be recycled, In Pollution on the environment in the treatment process of saltcake containing chromium is avoided while the anhydrous sodium sulfate product of production preparation high added value, The optimization for promoting chromic salts enterprise product structure, improves the economic benefit of enterprise.In addition, since present invention process is simple and easy to do, it is former Expect it is inexpensive, be conducive to promote, it is contemplated that have good market prospects.
Specific embodiment
Illustrate embodiments of the present invention below by way of specific specific example, those skilled in the art can be by this specification Other advantages and efficacy of the present invention can be easily understood for disclosed content.The present invention can also pass through in addition different specific realities The mode of applying is embodied or practiced, the various details in this specification can also based on different viewpoints and application, without departing from Various modifications or alterations are carried out under spirit of the invention.
Before further describing the specific embodiments of the present invention, it should be appreciated that protection scope of the present invention is not limited to down State specific specific embodiment;It is also understood that term used in the embodiment of the present invention is specific specific in order to describe Embodiment, rather than limiting the scope of protection of the present invention.
When embodiment provides numberical range, it should be appreciated that except non-present invention is otherwise noted, two ends of each numberical range Any one numerical value can be selected between point and two endpoints.Unless otherwise defined, the present invention used in all technologies and Scientific term is identical as the normally understood meaning of those skilled in the art of the present technique.Except specific method, equipment used in embodiment, Outside material, grasp and record of the invention according to those skilled in the art to the prior art can also be used and this Any method, equipment and the material of the similar or equivalent prior art of method described in inventive embodiments, equipment, material come real The existing present invention.
Embodiment 1
The method for preparing anhydrous sodium sulfate using saltcake containing chromium, comprising the following steps:
(1) it chromium saltcake will be contained will be dissolved in chromium-contained aluminum mud wash water and obtain the aqueous solution of saltcake containing chromium, and control gained awns containing chromium The concentration of sodium sulphate is 15% in glass gall solution;
(2) quantitative sodium thiosulfate, Cr VI and sodium thiosulfate mole will be added in the aqueous solution of saltcake containing chromium The ratio between number promotes Cr VI to be reduced into trivalent chromium for 1 ﹕ 2.7 under the conditions of 0.3Mpa and 130 DEG C, to be hydrated chrome green Form be precipitated;
(3) aqueous solution of saltcake containing chromium after reduction being neutralized with industrial sulphuric acid, pH value control is 7, and temperature is controlled at 95 DEG C, Promote water soluble trivalent chromium to form chromium hydroxide to be precipitated;
(4) neutralizer that upper step obtains is filtered in the plate and frame filter press with dolomite dust filtration adjuvant, dolomite Powder fineness is 0.045mm, obtains filtrate after filtering out chromium hydroxide;
(5) it is cleaned using the filtrate that the high-efficiency and precision decolorization filtering machine with atlapulgite absorbent obtains upper step Decoloration obtains aqueous sodium persulfate solution;
(6) aqueous sodium persulfate solution after removal of impurities decoloration is evaporated using mechanical recompression evaporator, and anhydrous sodium sulfate is precipitated Crystal;
(7) gained anhydrous slufuric acid sodium crystal is delivered to continuous after carrying out continuous centrifugal separation with Horizontal Centrifuge It is dry in boiling drier, it is packed after dry and obtains anhydrous sodium sulfate product, it is anhydrous that product meets GB/T6009-2014 industry Sodium sulphate standard requirements.
Embodiment 2
The method for preparing anhydrous sodium sulfate using saltcake containing chromium, comprising the following steps:
(1) it chromium saltcake will be contained will be dissolved in the wash water of saltcake containing chromium and obtain the aqueous solution of saltcake containing chromium, and control gained awns containing chromium The concentration of sodium sulphate is 20% in glass gall solution;
(2) quantitative sodium thiosulfate, Cr VI and sodium thiosulfate mole will be added in the aqueous solution of saltcake containing chromium The ratio between number promotes Cr VI to be reduced into trivalent chromium for 1 ﹕ 3.0 under the conditions of 0.2Mpa and 120 DEG C, to be hydrated chrome green Form be precipitated;
(3) aqueous solution of saltcake containing chromium after reduction is neutralized with industrial sulphuric acid, pH value control is 6.7, and temperature is controlled 80 DEG C, promote water soluble trivalent chromium to form chromium hydroxide and is precipitated;
(4) neutralizer that upper step obtains is filtered in the plate and frame filter press with marble powder filtration adjuvant, marble Powder fineness is 0.050mm, obtains filtrate after filtering out chromium hydroxide;
(5) removal of impurities is carried out to the filtrate that upper step obtains using the high-efficiency and precision decolorization filtering machine with diatomite adsorbant to take off Color obtains aqueous sodium persulfate solution;
(6) aqueous sodium persulfate solution after removal of impurities decoloration is evaporated using mechanical recompression evaporator, and anhydrous sodium sulfate is precipitated Crystal;
(7) gained anhydrous slufuric acid sodium crystal is delivered to continuous shaking after carrying out continuous centrifugal separation with horizontal spiral centrifuge It is dry in fluid bed dryer, it is packed after dry and obtains anhydrous sodium sulfate product, product meets GB/T6009-2014 industry nothing Aqueous sodium persulfate standard requirements.
Embodiment 3
The method for preparing anhydrous sodium sulfate using saltcake containing chromium, comprising the following steps:
(1) it chromium saltcake will be contained will be dissolved in evaporation condensed water containing chromium and obtain the aqueous solution of saltcake containing chromium, and contain chromium obtained by controlling The concentration of sodium sulphate is 25% in saltcake aqueous solution;
(2) quantitative sodium thiosulfate, Cr VI and sodium thiosulfate mole will be added in the aqueous solution of saltcake containing chromium The ratio between number promotes Cr VI to be reduced into trivalent chromium for 1 ﹕ 2.8 under the conditions of 0.2Mpa and 120 DEG C, to be hydrated chrome green Form be precipitated;
(3) aqueous solution of saltcake containing chromium after reduction is neutralized with industrial sulphuric acid, pH value control is 7, and temperature is controlled 100 DEG C, promote water soluble trivalent chromium to form chromium hydroxide and is precipitated;
(4) neutralizer that upper step obtains is filtered in the plate and frame filter press with dolomite dust filtration adjuvant, dolomite Powder fineness is 0.1mm, obtains filtrate after filtering out chromium hydroxide;
(5) removal of impurities is carried out to the filtrate that upper step obtains using the high-efficiency and precision decolorization filtering machine with acticarbon to take off Color obtains aqueous sodium persulfate solution;
(6) aqueous sodium persulfate solution after removal of impurities decoloration is evaporated using mechanical recompression evaporator, and anhydrous sodium sulfate is precipitated Crystal;
(7) gained anhydrous slufuric acid sodium crystal is delivered to continuous after carrying out continuous centrifugal separation with Horizontal Centrifuge It is dry in paddle-dryer, it is packed after dry and obtains anhydrous sodium sulfate product, product meets GB/T6009-2014 industry nothing Aqueous sodium persulfate standard requirements.
Embodiment 4
The method for preparing anhydrous sodium sulfate using saltcake containing chromium, comprising the following steps:
(1) it chromium saltcake will be contained will be dissolved in roasting technique leaching waste water and obtain the aqueous solution of saltcake containing chromium, and contain obtained by controlling The concentration of sodium sulphate is 30% in chromium saltcake aqueous solution;
(2) quantitative sodium thiosulfate, Cr VI and sodium thiosulfate mole will be added in the aqueous solution of saltcake containing chromium The ratio between number promotes Cr VI to be reduced into trivalent chromium for 1 ﹕ 2.6 under the conditions of 0.3Mpa and 120 DEG C, to be hydrated chrome green Form be precipitated;
(3) aqueous solution of saltcake containing chromium after reduction is neutralized with industrial sulphuric acid, pH value control is 6.8, and temperature is controlled 75 DEG C, promote water soluble trivalent chromium to form chromium hydroxide and is precipitated;
(4) neutralizer for obtaining upper step is in the plate and frame filter press for having dolomite dust and marble powder hybrid filtering auxiliary agent Middle filtering, hybrid filtering auxiliary agent fineness are 0.2mm, obtain filtrate after filtering out chromium hydroxide;
(5) upper step is obtained using the high-efficiency and precision decolorization filtering machine with atlapulgite and diatomite mixed adsorbent Filtrate carries out removal of impurities decoloration and obtains aqueous sodium persulfate solution;
(6) aqueous sodium persulfate solution after removal of impurities decoloration is evaporated using mechanical recompression evaporator, and anhydrous sodium sulfate is precipitated Crystal;
(7) gained anhydrous slufuric acid sodium crystal is delivered to continuous after carrying out continuous centrifugal separation with Horizontal Centrifuge It is dry in pneumatic drier, it is packed after dry and obtains anhydrous sodium sulfate product, it is anhydrous that product meets GB/T6009-2014 industry Sodium sulphate standard requirements.
Embodiment 5
The method for preparing anhydrous sodium sulfate using saltcake containing chromium, comprising the following steps:
(1) saltcake containing chromium is dissolved in the waste water that chromium slag filters out and obtains the aqueous solution of saltcake containing chromium, and control gained containing chromium The concentration of sodium sulphate is 32% in saltcake aqueous solution;
(2) quantitative sodium thiosulfate, Cr VI and sodium thiosulfate mole will be added in the aqueous solution of saltcake containing chromium The ratio between number promotes Cr VI to be reduced into trivalent chromium for 1 ﹕ 3.2 under the conditions of 0.5Mpa and 130 DEG C, to be hydrated chrome green Form be precipitated;
(3) aqueous solution of saltcake containing chromium after reduction being neutralized with industrial sulphuric acid, pH value control is 7, and temperature is controlled at 85 DEG C, Promote water soluble trivalent chromium to form chromium hydroxide to be precipitated;
(4) neutralizer that upper step obtains is filtered in the plate and frame filter press with dolomite dust filtration adjuvant, dolomite Powder fineness is 0.3mm, obtains filtrate after filtering out chromium hydroxide;
(5) removal of impurities is carried out to the filtrate that upper step obtains using the high-efficiency and precision decolorization filtering machine with diatomite adsorbant to take off Color obtains aqueous sodium persulfate solution;
(6) aqueous sodium persulfate solution after removal of impurities decoloration is evaporated using mechanical recompression evaporator, and anhydrous sodium sulfate is precipitated Crystal;
(7) gained anhydrous slufuric acid sodium crystal is delivered to continuous after carrying out continuous centrifugal separation with Horizontal Centrifuge It is dry in flash dryer, it is packed after dry and obtains anhydrous sodium sulfate product, it is anhydrous that product meets GB/T6009-2014 industry Sodium sulphate standard requirements.
Quality testing
Carry out quality inspection to anhydrous sodium sulfate product obtained by above-described embodiment 1-5: detection method is referring to GB/T6009- 2014 industrial anhydrous sodium sulfate standard requirements;Cr VI detection uses diphenyl carbazide spectrophotometry.Testing result is as follows Shown in table 1:
1 anhydrous sodium sulfate product quality testing result of table
Detection project Embodiment 1 Embodiment 2 Embodiment 3 Embodiment 4 Embodiment 5 I class
Sodium sulphate w/% 99.80 99.65 99.62 99.74 99.66 ≥99.0
Water-insoluble w/% 0.002 0.002 0.003 0.002 0.003 ≤0.05
The total content of magnesium and calcium w/% 0.01 0.02 0.01 0.01 0.02 ≤0.15
Chloride (Cl) w/% 0.04 0.11 0.05 0.03 0.07 ≤0.35
Iron w/% 0.0005 0.0009 0.0003 0.0003 0.0005 ≤0.002
Moisture w/% 0.02 0.02 0.02 0.02 0.02 ≤0.20
Whiteness (R457)/% 89 88 90 89 88 ≥82
PH value (50g/L) 6.8 6.9 6.8 6.4 6.9 -
Cr VI (ppm) 5 7 5 4 4 -
The preferred embodiments of the disclosure and embodiment are explained in detail above, but the present invention is not limited to The above-described embodiment and examples can also not depart from this hair in the knowledge that those skilled in the art should have Various changes can be made under the premise of bright design.

Claims (2)

1. a kind of method for preparing anhydrous sodium sulfate using saltcake containing chromium, it is characterised in that the following steps are included:
(1) it chromium saltcake will be contained will be dissolved in chromate waste water and obtain the aqueous solution of saltcake containing chromium, and control the gained aqueous solution of saltcake containing chromium The concentration of middle sodium sulphate is 15-32%;
The chromate waste water is that the roasting technique generated in sodium dichromate production process leaches waste water, the waste water that chromium slag filters out, contains Chromium aluminium mud wash water, the wash water of saltcake containing chromium, chromic acid chromium wash water or evaporation condensed water containing chromium;
(2) quantitative sodium thiosulfate, Cr VI and sulphur in the aqueous solution of saltcake containing chromium will be added in the aqueous solution of saltcake containing chromium The ratio between sodium thiosulfate molal quantity is 1 ﹕ 2.6-3.6;
Under the conditions of 0.2-1Mpa and 120-190 DEG C, Cr VI is promoted to be reduced into trivalent chromium, to be hydrated the shape of chrome green Formula is precipitated;
(3) aqueous solution of saltcake containing chromium after reduction is neutralized to pH value with industrial sulphuric acid to control as 6.7-7, temperature is controlled in 40- 100 DEG C, promotes water soluble trivalent chromium to form chromium hydroxide and be precipitated;
(4) neutralizer that (3) step obtains is filtered in the plate and frame filter press with filtration adjuvant, is obtained after filtering out chromium hydroxide To filtrate;
Filtration adjuvant is any one of dolomite dust, marble powder or two kinds of composition;
The dolomite dust, marble powder fineness be 0.045-0.3mm;
(5) removal of impurities decoloration is carried out using the filtrate that the high-efficiency and precision decolorization filtering machine with adsorbent obtains (4) step to obtain Aqueous sodium persulfate solution;
The adsorbent is one of diatomite, atlapulgite, active carbon or a variety of;
(6) aqueous sodium persulfate solution after removal of impurities decoloration is evaporated using mechanical recompression evaporator, and anhydrous slufuric acid sodium crystal is precipitated;
(7) gained anhydrous slufuric acid sodium crystal is delivered in continuous drier dry after carrying out continuous centrifugal separation with centrifuge, is done Packaging obtains anhydrous sodium sulfate product after dry;
The centrifuge be Horizontal Centrifuge or horizontal spiral centrifuge,
The continuous drier is continuous flow drying machine, continuous boiling drier, successive flash vaporization drying machine, continuous shaking fluidisation Bed dryer or continuous paddle-dryer.
2. the method according to claim 1 for preparing anhydrous sodium sulfate using saltcake containing chromium, comprising the following steps:
(1) it chromium saltcake will be contained will be dissolved in chromate waste water and obtain the aqueous solution of saltcake containing chromium, and control the gained aqueous solution of saltcake containing chromium The concentration of middle sodium sulphate is 25%;
(2) will be added quantitative sodium thiosulfate in the aqueous solution of saltcake containing chromium, Cr VI and sodium thiosulfate molal quantity it Than promoting Cr VI to be reduced into trivalent chromium under the conditions of 0.3Mpa and 130 DEG C for 1 ﹕ 2.7, to be hydrated the shape of chrome green Formula is precipitated;
(3) aqueous solution of saltcake containing chromium after reduction is neutralized with industrial sulphuric acid, pH value control is 7, and temperature is controlled at 95 DEG C, is promoted Water soluble trivalent chromium forms chromium hydroxide and is precipitated;
(4) neutralizer that (3) step obtains is filtered in the plate and frame filter press with filtration adjuvant, the fineness of filtration adjuvant is 0.1mm obtains filtrate after filtering out chromium hydroxide;
(5) removal of impurities decoloration is carried out using the filtrate that the high-efficiency and precision decolorization filtering machine with adsorbent obtains (4) step to obtain Aqueous sodium persulfate solution;
(6) aqueous sodium persulfate solution after removal of impurities decoloration is evaporated using mechanical recompression evaporator, and anhydrous slufuric acid sodium crystal is precipitated;
(7) gained anhydrous slufuric acid sodium crystal is delivered in continuous drier dry after carrying out continuous centrifugal separation with centrifuge, is done Packaging obtains anhydrous sodium sulfate product after dry.
CN201711117496.0A 2017-11-13 2017-11-13 A method of anhydrous sodium sulfate is prepared using saltcake containing chromium CN107934993B (en)

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Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SU546565A1 (en) * 1975-01-02 1977-02-15 Предприятие П/Я А-1908 The method of producing chromium oxide
US5520902A (en) * 1994-11-25 1996-05-28 Occidental Chemical Corporation Process for making chromium-free orthorhombic sodium sulfate
CN1803615B (en) * 2006-01-04 2010-04-14 四川安县银河建化集团有限公司 Method for preparing potassium sulphate by chromium contained Glauber salt
CN101525189B (en) * 2009-04-02 2011-02-16 葫芦岛辉宏有色金属有限公司 Method for treating wastewater containing ammonia, vanadium, chrome and sodium sulfate
CN103739118B (en) * 2014-01-06 2016-01-20 博天环境集团股份有限公司 The treatment process of analysis
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

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