CN1212270C - Improved process for producing sodium ferrocyanide and potassium ferrocyanide - Google Patents

Improved process for producing sodium ferrocyanide and potassium ferrocyanide Download PDF

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CN1212270C
CN1212270C CN 99109095 CN99109095A CN1212270C CN 1212270 C CN1212270 C CN 1212270C CN 99109095 CN99109095 CN 99109095 CN 99109095 A CN99109095 A CN 99109095A CN 1212270 C CN1212270 C CN 1212270C
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reaction
prussiate
ferrocyanide
iron powder
cyanide
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CN1277938A (en
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罗必奎
雷洪
郑长春
陈小平
任鹰
李永芳
尹应武
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Beijing Tsinghua Unisplendour Insight Chemical Technology LLC
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Beijing Tsinghua Unisplendour Insight Chemical Technology LLC
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Abstract

The present invention relates to a new improved process for producing alkali metal ferrocyanide, particularly to a process for producing sodium ferrocyanide or potassium ferrocyanide. Particularly, the present invention relates to a new improved process for producing alkali metal ferrocyanide by using cyanide, water and ferrous powder as raw materials to react under the approximate temperature of 0 DEG C to 85 DEG C, particularly a method for producing sodium ferrocyanide or potassium ferrocyanide. The improved method has the advantages of simple required devices, mild operation conditions, high reacting conversion rate and good product quality, and the three wastes are few, so that the present invention is especially suitable for large-scale industrial production.

Description

A kind of method of producing the alkaline ferro prussiate
The present invention relates to a kind of new improved production alkaline ferro prussiate, the method for special yellow prussiate of soda or yellow prussiate of potash.Specifically, the present invention relates to a kind of new improved be raw material with prussiate, water, iron powder, under about 0 ℃ to 85 ℃ humidity, react, produce the method for alkaline ferro prussiate, particularly yellow prussiate of soda or yellow prussiate of potash.
Alkaline ferro prussiate such as yellow prussiate of soda and yellow prussiate of potash are commonly called as yellow prussiate of soda and yellow potassium prussiate, are a kind of important chemical material.
The method of existing in the prior art multiple production yellow prussiate of soda and yellow prussiate of potash.Raw material with iron source in the alkaline ferro prussiate is classified, and these production methods can be divided into ferrous salt method and iron powder method.
The ferrous salt method mainly contains, for example
(1) alkali metal cyanide, alkali (as alkali metal hydroxide or yellow soda ash) and ferrous salt (as ferrous sulfate or iron protochloride) reaction method.Referring to, for example, RO70 365; RO 66 514; RO 68 004; Chemical Engineering, 60 (2), 1953, the 240-243 pages or leaves; In these class methods, also comprise cyanide melt method, a kind of method of present suitability for industrialized production yellow prussiate of potash.So-called cyanide melt method is, cyanide fusant adds ferrous sulfate after adding the water extraction, reaction mixture is filtered, and reaction product in the filtrate and Repone K reaction, generation yellow prussiate of potash double salt precipitation carries out aftertreatment with it, obtains the product yellow prussiate of potash.
(2) prussic acid, oxyhydroxide and ferrous salt (as iron protochloride or ferrous sulfate) reaction method.Referring to, for example, CN 85106171A; CN 87106254A; US 3 695 833; RO 74 494.
(3) the Iron sulfuret reaction method of prussic acid, yellow soda ash.Referring to, for example, US 2 378 403.
The iron powder method mainly contains, for example
(1) sodium cyanide, water and iron powder reaction method.For example US2431601 discloses a kind of method, and this method is reacted sodium cyanide and iron powder between 90 ℃ to 110 ℃, too slow for fear of speed, in reaction process air is pressed in the reaction system.The way that is pressed into air is brought some defectives inevitably.One is pressed into air well-oxygenated environment is provided, and can cause the oxidation of iron powder, and a large amount of ferric oxide of generation must be removed before separating yellow prussiate.Its two, the appearance of oxide compound make with alkali metal cyanide can not complete reaction.Notice also that simultaneously in this reaction process, the dissolution rate of iron constantly reduces.Moreover one mole of product will produce two moles alkali again in the reaction process, thereby make system basicity bigger, be unfavorable for that equally reaction trends towards fully.The inevitable outcome that above-mentioned defective caused is the purity of reactor product and reaction conversion ratio all effected.
(2) liquid hydrogen cyanide, potassium hydroxide and iron powder method.The method of the production yellow prussiate of soda of 3 699 114 couples of above-mentioned US 2 431601 of US is improved, and is used to produce yellow prussiate of potash.This method is liquid hydrogen cyanic acid, under the excessive greatly situation of potassium hydroxide, 95 ℃ under the reaction system boiling temperature, react with iron powder.The reaction process of this method has several shortcomings, and one needs strict control to drip the speed of liquid prussic acid; Its two, promote the carrying out that react react the basicity (about 10%) bigger than normal of system afterwards because of needs add excessive greatly alkali; Its alkaline condition reaction more than three, 95 ℃ must cause that prussiate resolves into yellow soda ash, formic acid and ammoniacal liquor or the like.Just because of these problems are arranged, this method can not obtain high-quality product with high yield, and makes that suitability for industrialized production is difficult to realize.
In sum, though it is multiple that the method for production alkaline ferro prussiate has, and can not be entirely satisfactory, therefore, still need a kind of simpler, more economical, be more suitable in suitability for industrialized production alkaline ferro prussiate the method for particularly ferrocyanic sodium or sylvite.
The present inventor is by having carried out intensive research to the method for producing the alkaline ferro prussiate, the result is surprised to find that, adopting with the iron powder is in the reaction process of the iron source iron powder method of producing the alkaline ferro prussiate, by reducing temperature of reaction, can reach above-mentioned target, thereby finish the present invention.
Basic purpose of the present invention provides a kind of preparation method of alkaline ferro prussiate, it adopts prussiate, water, iron powder is raw material, with the raw material prussiate is benchmark, the amount of iron powder is required stoichiometric 1.5 to 20 times, control reaction temperature is 25 ℃ to 85 ℃, reaction is 2-8 hour under agitation condition, and wherein said prussiate is sodium cyanide or potassium cyanide, and perhaps described prussiate is gas cyaniding hydrogen and adopts auxiliary material sodium hydroxide or potassium hydroxide solution.
Another object of the present invention provides a kind of the overcome defective of production alkaline ferro prussiate in the prior art and the new production process of prejudice.
Other purpose of the present invention and advantage, will state hereinafter to the detailed description of specific embodiments and embodiment and manifest clearlyer.
The invention provides a kind of method of improved production alkaline ferro prussiate.This method is reacted under the temperature between 25 ℃ to 85 ℃ with prussiate, water, iron powder material, produces alkaline ferro prussiate yellow prussiate of soda or yellow prussiate of potash in this way.
The above-mentioned raw materials prussiate can be solid or liquid or gas.According to actual needs, can utilize any raw material prussiate.The raw material prussiate is sodium cyanide or potassium cyanide preferably, and liquid or gas cyaniding hydrogen are preferred equally.Under the situation that adopts prussic acid, also should adopt alkali metal hydroxide, for example, as required, adopt sodium hydroxide or potassium hydroxide.With prussic acid and alkali metal hydroxide reaction, generate sodium cyanide or potassium cyanide, it is used for and water and iron powder reaction.Prussic acid and alkali metal hydroxide such as sodium hydroxide or potassium hydroxide reaction, the mode of generation alkali metal cyanide such as sodium cyanide or potassium cyanide is well-known to those skilled in the art.
Temperature of reaction can be 25 ℃ to 85 ℃, preferably 25 ℃ to 60 ℃.
According to the difference of used application of temperature, the reaction times can be 2 to 8 hours.
Used iron powder should adopt thin iron powder, preferred 20 orders or lower.Iron powder can adopt technical grade or analytical pure or reduced iron powder.
For obtaining gratifying yield, reaction completely and rational reaction times, iron powder is excessive with respect to the alkali metal cyanide stoichiometry to be essential.Generally speaking, be benchmark with the raw material prussiate, the consumption of iron powder is required stoichiometric 1.5 to 20 times.
Reaction is normally carried out under normal pressure.Yet, the inventive method also can the pressurization or the decompression under---normally 0.1 the crust to 10 the crust pressure under carry out.
The reaction actually operating in, the collection of reaction product with separate be with ordinary method carry out (referring to, embodiment).
An embodiment of the present invention is a kind of method of producing yellow prussiate of soda.This method adopts thin iron powder, sodium cyanide, water, and control reaction temperature is preferably reacted under 25 ℃ to 60 ℃ temperature at 25 ℃ to 85 ℃.
According to the difference of used reaction temperature, the reaction times can be 2 to 8 hours.
Used sodium cyanide can be a liquid, also can be solid.Also can and obtain with the reaction of prussic acid and sodium hydroxide.Under the situation that adopts prussic acid, also should adopt sodium hydroxide.Prussic acid can adopt gas or liquid.Under the situation that adopts liquid hydrogen cyanide, with prussic acid fluid drips hydro-oxidation sodium water solution or in the aqueous sodium hydroxide solution that iron powder is stirring.The concentration of aqueous sodium hydroxide solution can change in wide scope, and preferred concentration is 5-50%.Under the situation of prussic acid gas, prussic acid fed aqueous sodium hydroxide solution or in the aqueous sodium hydroxide solution that iron powder is stirring.When adopting prussic acid liquid, in reaction process, prussic acid liquid can be controlled at same drop rate or different drop rate drips continuously or intermittently.When adopting prussic acid gas, answering in the process, prussic acid gas can be controlled at same feeding speed or different feeding speed continuously or interrupted the feeding.
Iron powder is excessive with respect to the sodium cyanide stoichiometry to be essential.Generally speaking, be benchmark with the raw material prussiate, the consumption of iron powder is required stoichiometric 1.5 to 20 times.
Another embodiment of the present invention is a kind of method of producing yellow prussiate of potash.This method adopts thin iron powder, potassium cyanide, water, and control reaction temperature is preferably reacted under 25 ℃ to 60 ℃ temperature at 25 ℃ to 85 ℃.
According to the difference of used temperature of reaction, the reaction times can be 2 to 8 hours.
Used potassium cyanide can be liquid, also can be solid.Also can and obtain with the reaction of prussic acid and potassium hydroxide.Under the situation that adopts prussic acid, also should adopt potassium hydroxide.Prussic acid can adopt gas or liquid.Adopting under the situation of liquid hydrogen cyanide, the prussic acid fluid drips is being added to aqueous sodium hydroxide solution or in the potassium hydroxide aqueous solution that iron powder is stirring.The concentration of potassium hydroxide aqueous solution can change in wide scope, and preferred concentration is 5-50%.Under the situation of prussic acid gas, prussic acid is fed potassium hydroxide aqueous solution or stirring in the potassium hydroxide aqueous solution with iron powder.When adopting prussic acid liquid, in reaction process, prussic acid liquid can be controlled at same drop rate or different drop rate drips continuously or intermittently.When adopting prussic acid gas, in reaction process, prussic acid gas can be controlled at same feeding speed or different feeding speed feeds continuously or intermittently.
Iron powder is excessive with respect to the potassium cyanide stoichiometry to be essential.Generally speaking, be benchmark with the raw material prussiate, the amount of iron powder is required stoichiometric 1.5 to 20 times.
(US2431601, US3699114) compares with iron powder method of the prior art, the method of improved production alkaline ferro prussiate newly provided by the present invention, overcome above-mentioned defective of the prior art, and overcome in the prior art and need under the high-temperature of reaction system boiling temperature, react at 90 ℃ or 95 ℃ so that the prejudice of reaction rate accelerates.The inventive method is reacted under promptly about 25 ℃ to 85 ℃ temperature of reaction under the temperature condition of lower milder, and in fact speed of reaction does not reduce, and high conversion to obtain product content be the above product of 98-99% (>97%).
In sum, novel method of the present invention makes reaction conditions gentle more by the improvement to original method, and easy handling, and reaction conversion ratio height had both obtained the high-quality alkaline ferro prussiate of high-content, also can cut down the consumption of energy greatly.Become very easy for pushing big industrial production to.
Following embodiment is used for illustrating further the present invention, but is not to be intended to limit the scope of the invention by any way.
Embodiment 1:
In the 250ml four-hole bottle, add 50g 100 order iron powders, add 100g 31% sodium cyanide solution, heating in water bath, temperature of reaction is controlled at 25-55 ℃, stirring reaction 7 hours.Leave standstill, inclining supernatant liquid, filters, and removes solid impurity.Each stirs washing iron powder down with 50ml hot water at twice.Leave standstill, inclining the upper strata washing lotion, filters, and removes solid impurity.Washing lotion concentrates with reaction solution, when occurring solids in the solution and occur, allows it slowly be cooled to crystallizing at room temperature.Filter, leach the thing drying, get the 49.47g yellow prussiate of soda, wherein the ferrocyanide sodium content is 95.4%, and sodium hydrate content is 0.75%, and the crystalline mother solution weight that leaches is 48g, and wherein the ferrocyanide sodium content is 5.46%.The yellow prussiate of soda water recrystallization of above-mentioned content 95.4% is handled, got the 44.50g yellow prussiate of soda, wherein the ferrocyanide sodium content is 99.2%, and sodium hydrate content is 0.03%.Transformation efficiency to sodium cyanide is 97.6%.Crystalline mother solution and the iron powder cover that washes out are used for reacting next time.
Embodiment 2-7 employing is carried out with the description similar methods among the embodiment 1.Reaction conditions with the results are shown in the following table 1.
Table 1
Embodiment number Iron powder (g) Prussiate Prussiate weight (g) Cyanide content (%) Temperature (℃) Time (hour) The gross weight of reaction solution and washing lotion 1)(g) The content of product (%) in reaction solution and the washing lotion Folding hundred must be measured (g) Theoretically must measure (g) Transformation efficiency (%) Remarks
2 15 NaCN 100 31 40-60 6 192 26.20 50.37 51.03 98.70
3 15 NaCN 100 31 55-70 5 185 27.00 50.03 51.03 98.03
4 15 NaCN 100 31 70-85 4 180 27.70 49.81 51.03 97.60
5 20 KCN 50 90 70-85 5 184 25.90 47.74 48.65 98.13 Reaction adds water 70kg
6 10 NaCN 100 31 70-85 5 180 27.90 50.27 51.03 98.50
7 300 NaCN 300 10 70-85 2 374 13.30 49.68 51.03 97.35
Annotate: change in reaction conditions
1) washing lotion and the reaction solution of the merging before concentrating.
Embodiment 8:
Add 100ml water in the bottle of a 250ml, 29.8g content is 94% potassium hydroxide solid, stirs after dissolving, add 10g 100 order iron powders and stir, heating in water bath, temperature of reaction is controlled at 30-40 ℃, with the 4 hours slow 29.2g liquid hydrogen cyanic acid that adds, continued stirring reaction again 4 hours.Leave standstill, inclining the upper strata reaction solution, reaction solution removes solid impurity after filtration.Add the product in the 50ml hot wash iron powder in reaction flask, leave standstill after fully stirring, inclining washing lotion, after adding 50ml hot water fully stirs in bottle again, leaves standstill, and inclining washing lotion.Washing lotion merges in the reaction solution after filtering, and reaction solution and washing lotion are concentrated together, when occurring solids in the solution and occur, allows it slowly be cooled to crystallizing at room temperature.Filter, leach the thing drying and get dry product 46.60g yellow prussiate of potash, wherein the ferrocyanide potassium content is 98.80%, the crystalline mother solution weight that leaches is 70g, wherein the ferrocyanide potassium content is 8.13%, alkali content is 6.10g/L, and the amount that contains pure yellow prussiate of potash in the mother liquor is 5.69g, and dry product adds that the weight of pure yellow prussiate of potash amounts to 51.74g in the crystalline mother solution.Product is 98.00% to the transformation efficiency of potassium hydroxide.
Comparative examples 1:
In the 250ml four-hole bottle, add 50g 100 order iron powders, add 100g 31% sodium cyanide solution, the oil bath heating blasts pressurized air in bottle, and temperature of reaction is controlled at 100-110 ℃, stirring reaction 4 hours.Leave standstill, inclining supernatant liquid.Reaction solution is removed solid impurity after filtration.Each stirs washing iron powder down with 50ml hot water at twice.Leave standstill, inclining the upper strata washing lotion, filters, and removes solid impurity.Washing lotion and reaction solution weight amount to 180g, and wherein the ferrocyanide sodium content is 25.9%, and it is 46.69g that yellow prussiate of soda is rolled over hundred weight, and theoretical must measuring is 51.03g, to the transformation efficiency 91.50% of sodium cyanide.
Comparative examples 2:
In the 250ml four-hole bottle, add 50g 100 order iron powders, add 50g content and be 90% potassium cyanide solid, add 100ml water, the oil bath heating blasts pressurized air in bottle, and temperature control is 100-110 ℃ of reaction, stirring reaction 4 hours.Leave standstill, inclining supernatant liquid.Reaction solution is removed solid impurity after filtration.Each stirs washing iron powder down with 50ml hot water at twice.Leave standstill, inclining the upper strata washing lotion, filters, and removes solid impurity.The weight of washing lotion and reaction solution amounts to 241g, and wherein the ferrocyanide potassium content is 18.7%, and it is 44.95g that yellow prussiate of potash is rolled over hundred weight, theoretically must measure 48.65g.Transformation efficiency 92.40% to potassium cyanide.
Comparative examples 3:
In the 250ml four-hole bottle, add 100g 100 order iron powders, adding 100g content is 31% sodium cyanide solution, the oil bath heating, temperature control was 100-110 ℃ of reaction 4 hours.Leave standstill, inclining supernatant liquid, filters, and removes solid impurity.Each stirs washing iron powder down with 50ml hot water at twice.Leave standstill, inclining the upper strata washing lotion, filters, and removes solid impurity.Washing lotion concentrates with reaction solution, when occurring solids in the solution and occur, allows it slowly be cooled to crystallizing at room temperature.Filter, leach the thing drying, obtain the 46.53g yellow prussiate of soda, wherein the ferrocyanide sodium content is 95.00%, and the amount of sodium hydroxide is 1.67%.The crystalline mother solution weight that leaches is 49g, and wherein the content of yellow prussiate of soda is 5.1%.The yellow prussiate of soda water recrystallization of content 95.00% is handled, got the 40.22g yellow prussiate of soda, wherein the content of yellow prussiate of soda is 99.10%, and the content of sodium hydroxide is 0.02%.Transformation efficiency 91.50% to sodium hydroxide.

Claims (2)

1, a kind of preparation method of alkaline ferro prussiate, it adopts iron powder, water, prussiate is raw material, with the raw material prussiate is benchmark, the amount of iron powder is required stoichiometric 1.5 to 20 times, control reaction temperature is 25-85 ℃, reaction is 2-8 hour under agitation condition, and wherein said prussiate is sodium cyanide or potassium cyanide, and perhaps described prussiate is gas cyaniding hydrogen and adopts auxiliary material sodium hydroxide or potassium hydroxide solution.
2, according to the process of claim 1 wherein that described temperature of reaction is 25-60 ℃.
CN 99109095 1999-06-21 1999-06-21 Improved process for producing sodium ferrocyanide and potassium ferrocyanide Expired - Fee Related CN1212270C (en)

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CN103818931B (en) * 2014-02-28 2015-11-18 重庆紫光化工股份有限公司 The process for cleanly preparing of yellow prussiate of potash
CN106115739B (en) * 2016-06-29 2018-02-13 晋城市鸿生化工有限公司 A kind of production method of yellow sodium prussiate
CN106348317B (en) * 2016-09-30 2019-04-23 河北诚信有限责任公司 A kind of continuous production technology and its process units of potassium ferrocyanide
US10147947B2 (en) * 2017-03-20 2018-12-04 Natron Energy, Inc. Purification and use of ferrocyanide solutions

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