CN1110665A

CN1110665A - Production of ferrous sulfate monohydrate with liquid-phase forced dewatering method

Info

Publication number: CN1110665A
Application number: CN 95101641
Authority: CN
Inventors: 刘一峰
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-02-24
Filing date: 1995-02-24
Publication date: 1995-10-25

Abstract

The process features that under a certain condition, FeSO4.7H2O is forced to dewater sulfuric acid solution as dewatering agent to generate FeSO4.H2O. If sulfuric acid and iron or iron-containing material are used to produce FeSO4.H2O, the sulfuric must be first used as liquid-phase dewatering agent of FeSO4.7H2O and then takes part in reaction on iron or iron-containing material to generate FeSO4.7H2O. Its advantages include low energy consumption, high productivity and high quality of product.

Description

Production of ferrous sulfate monohydrate with liquid-phase forced dewatering method

The invention provides a kind of novel method of producing the inorganic salt ferrous sulfate monohydrate.

As everyone knows, ferrous sulfate has purposes extremely widely in all many-sides such as industry, agricultural, forestry, and only fodder industry just reaches ten thousand tons at the annual consumption of China, but also is increasing year by year; Also rather considerable on the agricultural as little fertile its pent-up demand amount of using.In the market the most commonly with the ferrous sulfate of seven crystal water, producing the most general method of iron vitriol and be with sulfuric acid and scrap iron is that the raw material direct reaction makes.We know that iron vitriol character is very unstable, very easily weathering in the exsiccant air, and in malaria very easily oxidized generation yellowish brown ferric subsulfate.Iron vitriol product is on the market gone out to finally transporting to the user when using by manufacturer production, all exists the phenomenon of deterioration by oxidation more or less.This has brought more masty problem not only for packing, transportation and preservation etc., and finally can have influence on result of use.With the fodder industry is example, and after the iron vitriol that exists the deterioration by oxidation problem was sneaked into feed as trace mineral supplement, it was exactly inevitable that its bioavailability reduces.It has been recognized that some defectives of iron vitriol, begin to note having the ferrous sulfate monohydrate of suitable improvement, particularly in fodder industry, caused people's interest than iron vitriol character.

The a small amount of ferrous sulfate monohydrate commodity that occur on the market all are to be made through the gas phase drying and dehydrating by iron vitriol by classical way, as the described method of CN87102022A now.There are some problems in this method.At first owing to be subjected to the restriction of iron vitriol fusing point, drying must progressively be carried out, and is consuming time very long, and secondly the removing of six crystal water in the iron vitriol relies on thermal evaporation fully, and it is very big to consume energy.The dehydration of gas phase spraying drying may make shorten time of drying, but from aspects such as energy consumption, facility investment and technological operations, the cost of product will increase severely.At last, because time of drying is long, produce high price iron unavoidably in the product, and the particle degree of drying differ cause crystal water number irregularity, iron-holder is on the low side and unstable, this also is that on the market ferrous sulfate monohydrate product all is one of beige or linen major reason at present.As everybody knows, the ferrous sulfate monohydrate of standard should be lily.

The present invention has provided the method that solves the problems referred to above that ferrous sulfate monohydrate products production and quality product in the market exist, owing to easily implement, thereby have the value of commercial exploitation.

According to method of the present invention, provide two kinds of technological processs of producing ferrous sulfate monohydrate at this.Fig. 1 produces ferrous sulfate monohydrate by iron vitriol, and Fig. 2 is by sulfuric acid and iron or iron-bearing material production ferrous sulfate monohydrate, can introduce the present invention in detail in view of the above.

In the present invention, the dehydrating agent that at first places reactor is 50～98%(weight) sulfuric acid solution, stir and to rise to after 70～110 ℃ when progressively heating up or when temperature down, be that 1:3.00～30.00 join ferrous sulfate heptahydrate in the reactor in the dehydrating agent solution gradually by the weight ratio of dehydrating agent and ferrous sulfate heptahydrate, finish and keep 70～110 ℃ of dewatering system temperature. Because sulfuric acid has very strong dehydrating function, and just beginning dehydration at 64.4 ℃, ferrous sulfate heptahydrate is converted into ferrous sulfate monohydrate, therefore the present invention institute to system under the condition in the ferrous sulfate heptahydrate dehydration become the ferrous sulfate monohydrate pressure and carry out, this process is very fast, keep good stirring under 70～110 ℃, in 0.5～1.5 hour, can finish. The highly acid of dewatering system and faster dewatering speed got rid of oxidation of divalent and become ferric possibility, also so that the degree height of particle dehydration is consistent, this just provides very necessary condition for producing lily ferrous sulfate monohydrate product in good stirring. After dehydration is finished, carry out liquid-solid phase and separate, separation can adopt the mode of filtration to carry out. So far, dehydrating agent is owing to obtain the moisture content that ferrous sulfate heptahydrate loses, and itself has obtained dilution, after isolating through or still can be used as dehydrating agent and return use without adjusting, but must guarantee that the dehydrating agent sulfuric acid concentration is 50～98% in the reactor. Isolated ferrous sulfate monohydrate product can descend dry 0.5～1.0 hour at 80～100 ℃ then with a little ethanol washing, obtained at last meticulous, the lily ferrous sulfate monohydrate product of particle.

Below as can be seen, the whole process dewatering system is just kept necessary temperature in a short period of time, and time of drying is not long yet, so total energy consumption is very little; Simultaneously since in the reactor unit volume liquid-phase dehydration to handle capacity very big and process cycle is very short, so throughput is high, this be gas phase drying and dehydrating method production ferrous sulfate monohydrate can't compare.

Above-mentioned explanation can be described as the detailed explanation to Fig. 1.Fig. 2 is the extension of Fig. 1, and it produces iron vitriol from sulfuric acid and iron charge reaction.At this moment, sulfuric acid must be at first uses as the liquid-phase dehydration agent of iron vitriol, and after dehydration was finished, the dewatering agent after the dilution was isolated and spent the reaction that generates iron vitriol with iron or iron-bearing material again.We know, the vitriol oil can not be directly and the iron reaction generate iron vitriol, therefore present factory will go behind its thin up and the iron reaction again, promptly have the technological process of a concentrated acid dilution all the time.The present invention is quite different, except the production of first batch of iron vitriol needs the diluting concentrated sulfuric acid operation, continuous production has just saved this process, because in the present invention, the dilution of concentrated acid is to realize by the dehydration that obtains iron vitriol, and the vitriolic function has obtained fully playing among visible the present invention.

According to method of the present invention, under the secure situation of raw materials quality, can produce and contain ferrous iron and be not less than 32.0% pure white ferrous sulfate monohydrate product.

Embodiment 1:

In 500 milliliters beaker, insert 50% sulfuric acid, 195 grams, start and stir and intensification, progressively add iron vitriol 700 grams, finish and be warming up to 85～90 ℃ of continuation stirrings 1.0 hours, filter then, a little washing with alcohol of ferrous sulfate monohydrate, take out 80～90 ℃ of dryings 0.5 hour, claim to such an extent that the meticulous ferrous sulfate monohydrate 375 of pure white particle restrains.Its iron-holder is more than 32.0% after measured.

Claims

1, a kind of novel method of producing ferrous sulfate monohydrate, it is characterized in that: ferrous sulfate monohydrate generates by making iron vitriol forced dehydration in the dewatering agent sulphuric acid soln under certain condition, and if with sulfuric acid and iron or iron-bearing material production ferrous sulfate monohydrate, then sulfuric acid must be at first uses as the liquid-phase dehydration agent of iron vitriol, just generates the reaction of iron vitriol then with iron or iron-bearing material.

2, method according to claim 1 is characterized in that iron vitriol when liquid phase is forced to dewater, and the dewatering agent that is adopted is a sulphuric acid soln, and its sulfuric acid concentration is 50～98%(weight); The weight ratio of dewatering agent and iron vitriol is 1:3.00～30.00; Dehydration temperaturre is 70～110 ℃; Dewatering time is 0.5～1.5 hour; In the whole dehydration, dewatering system is fully stirred.

3, method according to claim 1, it is characterized in that dewatering agent is finished becomes after the effect of ferrous sulfate monohydrate iron vitriol dehydration, itself has obtained dilution dewatering agent, from dewatering system, isolate then, can continue to serve as to the dewatering agent of iron vitriol or be used for generating the reaction of iron vitriol with iron or iron-bearing material.