CN110526745A - A method of separation of phosphorus and phosphate fertilizer is prepared from dephosphorization steel slag - Google Patents
A method of separation of phosphorus and phosphate fertilizer is prepared from dephosphorization steel slag Download PDFInfo
- Publication number
- CN110526745A CN110526745A CN201910915755.7A CN201910915755A CN110526745A CN 110526745 A CN110526745 A CN 110526745A CN 201910915755 A CN201910915755 A CN 201910915755A CN 110526745 A CN110526745 A CN 110526745A
- Authority
- CN
- China
- Prior art keywords
- steel slag
- dephosphorization
- phosphorus
- separation
- phosphate fertilizer
- 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
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05B—PHOSPHATIC FERTILISERS
- C05B17/00—Other phosphatic fertilisers, e.g. soft rock phosphates, bone meal
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B3/00—General features in the manufacture of pig-iron
- C21B3/04—Recovery of by-products, e.g. slag
- C21B3/06—Treatment of liquid slag
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Fertilizers (AREA)
- Processing Of Solid Wastes (AREA)
Abstract
The invention belongs to Metallurgical resources reutilization technology fields, and in particular to a method of separation of phosphorus and phosphate fertilizer is prepared from dephosphorization steel slag, first dephosphorization steel slag is subjected to oxidation processes in the molten state, crushing grinding is carried out to it after cooling.Then dephosphorization steel slag is subjected to Selectively leaching in aqueous solution, the pH value for controlling ore pulp is 3.0~4.5, so that the solid solution phase of rich phosphorus in dephosphorization steel slag is dissolved and is separated, low-phosphorous residue and phosphorous leachate are obtained after reaction.Again by adding alkaline matter into phosphorous leachate, the pH value of leachate is increased, the phosphorus in leachate is made to form synthos precipitating.Synthos precipitating after separation can be used directly as phosphate fertilizer, and low-phosphorous residue then uses in sintering or steel-making.The phosphorus in dephosphorization steel slag is separated to energy high efficiency, low cost of the present invention, and then is prepared for phosphate fertilizer.It is more than that 92% phosphorus is recovered in the form of phosphate fertilizer, while residue recycles in Ferrous Metallurgy, realizes the resource utilization of dephosphorization steel slag in dephosphorization steel slag.
Description
Technical field
The invention belongs to Metallurgical resources reutilization technology fields, and in particular to a kind of separation of phosphorus and preparation from dephosphorization steel slag
The method of phosphate fertilizer.
Background technique
The steel production capacity in China is huge, and nearly 100,000,000 tons of the steel slag total amount generated every year.Because of the physico-chemical property and technology of steel slag
Limitation, the slag comprehensive utilization rate in China are lower.Currently, main slag processing mode be by molten steel slag it is cooling broken after,
It carries out magnetic separation and separates slag steel, remaining tailings is for construction material, road engineering or directly accumulation.These are not filled using method
The potential value of steel slag is waved in distribution, causes the huge wasting of resources and environmental pollution.Therefore, how efficiently resource utilization
Steel slag is iron and steel enterprise's project urgently to be resolved.
As steel require phosphorus content the raising of phosphorus content in increasingly strict and iron ore, many steel mills are in steelmaking process
In use dephosphorization of molten iron technique.This technique has divided traditional steel-making function, reduces molten iron as much as possible before molten steel decarburization
Middle phosphorus content, and generate dephosphorization steel slag.Since the molten iron after dephosphorization contains only a small amount of phosphorus, converter decarbonizing process can be in few slag situation
It is lower quickly to carry out, and the decarburization steel slag generated can return to dephosphorizing process as flux.This not only reduces steel slag yield, improve
Production efficiency, and make it possible the smelting of high phosphorus hot metal.
Currently, the dephosphorization technology of mainstream includes converter duplex method and converter double slag process (MURC).Converter duplex method is to use
Two converters, carry out dephosphorization treatment to molten iron first in first converter, and the molten iron after dephosphorization pours into second converter and carries out
Carbonization treatment.Converter double slag process refers to that dephosphorization and decarburization carry out respectively in same converter, first progress dephosphorization treatment, by dephosphorization
After steel slag discharge, retain molten iron and continue carbonization treatment, then pour out molten steel, retains decarburization steel slag for next furnace molten iron
Dephosphorization.
Due to the recycling of decarburization steel slag, dephosphorization steel slag is mainly discharged using the steelmaking process of dephosphorization of molten iron technique.With
Traditional steel slag is compared, and dephosphorization steel slag has lower basicity (CaO and SiO2Mass fraction ratio be 1.2~2.2), and contain
2~10% P2O5.Although the phosphorus content in dephosphorization steel slag is lower compared with rock phosphate in powder, since China generates a large amount of steel every year
Slag, the storage total amount of phosphorus is huge in steel slag.Therefore, dephosphorization steel slag is a kind of potential phosphor resource.If in dephosphorization steel slag
Phosphorus can be used for producing phosphate fertilizer by separation and Extraction, and the steel slag after dephosphorization can be used as flux for metallurgy and be recycled in steel mill,
Realize the resource utilization of steel slag.The extraction of phosphorus has the development of steel and iron industry and phosphate industry great in dephosphorization steel slag
Meaning.
Mineral facies in dephosphorization steel slag are mainly the solid solution phase (2CaOSiO that dicalcium silicate and tricalcium phosphate are formed2–
3CaO·P2O5), magnesium wollastonite phase (3CaOMgO2SiO2), matrix phase (CaO-SiO2–Fet) and Zeylanite phase O
(FetO–MgO–MnO).P elements distribution ratio with higher between solid solution phase and other mineral facies, illustrates that phosphorus is mainly rich
Collection is in solid solution phase.Therefore, in dephosphorization steel slag the separation of phosphorus depend primarily on rich phosphorus solid solution phase and other mineral facies
Separation.
According to the difference of physicochemical properties between mineral facies each in steel slag, many steel slag dephosphorizing technologies are just studied to be opened
Hair.Through patent retrieval, mainly there is technical solution below: the recycling of Chinese patent<phosphorus element from converter duplex dephosphorized slag>, Shen
Please number be 201010171945.1, develop it is a kind of using magnetic separation technology by phosphorus non-magnetic phase rich in dephosphorization steel slag and rich ferromagnetism
Mutually it is separately recovered；Chinese patent<a kind of steel slag recoverying and utilizing method>, application No. is 201410352003.1, develops a kind of benefit
With the processing method being recycled after rich phosphorus solid solution in floatation process removing steel slag；Japan Patent < steel processed ス ラ グ か ら
Iron and び Phosphorus recovery method >, Publication No. JP2014-1456A develops a kind of reduced steel slag and obtains the side of ferrophosphor(us)
Then method obtains high phosphorus slag to alloy dephosphorization again, as phosphor resource.These patented technologies have processing cost high, and dephosphorization is imitated
The disadvantages of rate is low, and isolated phosphorus is underused, therefore also non-large-scale application is in actual production.
Solid solution phase (the 2CaOSiO of rich phosphorus in dephosphorization steel slag2–3CaO·P2O5) solubility with higher in water,
And other iron-containing mineral phase solubilities are lower, therefore can separate the phosphorus in dephosphorization steel slag using the method leached.The present invention
People is at paper " ISIJ International ", Vol.58 (2018), proposes this method and work in No.5, pp.833-841
Skill: dephosphorization steel slag being leached in aqueous solution, dissolves solid solution phase individually, and matrix phase and iron magnesium phase are then retained in steel
Phosphorous leachate is obtained in slag, after leaching.Japan Patent < high concentration To Phosphorus The takes off Phosphorus ス ラ グ か ら Phosphorus containing む and separates back
Receiving method >, Publication No. JP2019-26865A leaches the high phosphorus slag after modification using this method, separates and recycle
Phosphorus in steel slag, the overall recovery of phosphorus are more than 70%.A kind of Chinese patent <biomass lime-ash modification converter slag dephosphorization circulation
>, application No. is 201811183045.1, develops a kind of pair of steel slag and carry out modifying process, then obtain liquid fertilizer using leaching
Expect, the dissolution rate of phosphorus reaches 90% in steel slag, but about 10% iron dissolves out simultaneously.Above two patented technologies have used price
Expensive citric acid solution, and need to add modification agent to steel slag modification, lead to complex process, production cost is high.
The above-mentioned each patented method of comprehensive analysis, leaching-out technique are a kind of effective ways that phosphorus is recycled from dephosphorization steel slag,
But the technique developed at present haves the defects that different, and practicability is low, it is difficult to industrial applications.
Summary of the invention
In order to solve the above technical problems, the present invention provides a kind of from dephosphorization steel slag separation of phosphorus and the side for preparing phosphate fertilizer
Method, in view of the above shortcomings of the prior art, the technical problems to be solved by the present invention are: providing a kind of high efficiency, low cost, suitable
The phosphorus in dephosphorization steel slag is leached and separated for industrial production, energy effective selectivity, further prepares the method for phosphate fertilizer；Make simultaneously
Dephosphorization steel slag after dephosphorization recycles in iron and steel enterprise as a kind of flux for metallurgy, realizes the resource utilization of steel slag, exploitation
Out in steel slag each component potential value.Dephosphorization steel slag carries out oxidation processes under high temperature fused state first in the present invention, makes
The mass fraction of FeO is lower than 8% in steel slag.After dephosphorization steel slag Slow cooling, crushing grinding is carried out to it.Later, by dephosphorization steel
Slag and aqueous solution are mixed to get ore pulp and carry out Selectively leaching.During Selectively leaching, hydrochloric acid and/or nitric acid solution are utilized
The pH value for controlling ore pulp is 3.0~4.5.After reaction, isolated low-phosphorous residue and phosphorous leachate.Low-phosphorous residue mainly contains
Iron, calcium and manganese can recycle in Ferrous Metallurgy.By adding alkaline matter into phosphorous leachate, the pH of leachate is increased
Value, until there is a large amount of white precipitate to generate.Precipitating after separation mainly contains synthos, can use directly as phosphate fertilizer.
(1) in steelmaking process, the dephosphorization steel slag after dephosphorization is poured into slag ladle, then the steel slag of high-temperature fusion is blown rapidly
Oxygen or air carry out oxidation processes, metallic iron and FeO in dephosphorization steel slag are made quickly to be oxidized into Fe2O3.This is because
Research " Journal of Sustainable Metallurgy " before, Vol.4 (2018) are sent out in No.4, pp.443-454
It is existing, when there are when a large amount of FeO, the dissolution rate of phosphorus is lower in steel slag when leaching and the dissolution rate of iron is higher, unfavorable in dephosphorization steel slag
In Selectively leaching.In addition, being difficult to prepare the phosphate fertilizer of high-quality using the leachate rich in iron ion.To realize ideal selection
Property leach and prepare phosphate fertilizer, the oxidation processes of steel slag are necessary.Because steelmaking process is also oxidation reaction, at the oxidation of steel slag
Reason can be carried out using existing equipment, without adding extras.When oxidation processes, the oxidation reaction of FeO is exothermic reaction, institute
It is not necessarily to heat source with this process, has saved mass energy.P elements will do it reallocation in the dephosphorization steel slag oxidation process of melting
And enrichment.After oxidation processes, make the mass fraction of FeO in dephosphorization steel slag lower than 8%.
(2) after oxidation processes, by the dephosphorization steel slag Slow cooling of melting, and cooling velocity is controlled, promotes to be dissolved in steel slag
The enrichment of body and crystal grain are grown up, while iron-containing mineral facies being made to crystallize precipitation from liquid slag.When temperature is lower than 1100 DEG C, steel
The composition of each mineral facies and metamorphosis very little in slag.Therefore, when steel slag is cooled to 1100 DEG C from molten condition, control cooling
Speed is lower than 10 DEG C/min.Dephosphorization steel slag after cooling is subjected to multiple stage crushing and grinding by crusher and ball mill, makes steel
The granularity of slag is less than 0.1mm, and the solid solution phase convenient for phosphorus rich in steel slag sufficiently exposes, and increases its surface area, promotes solid solution phase
Dissolution separation in leaching process.
(3) dephosphorization steel slag obtained in step (2) and aqueous solution are mixed to get ore pulp and carry out Selectively leaching, simultaneously
Mechanical stirring is carried out to ore pulp, accelerates reacting between steel slag particle and aqueous solution, improves the dynamic conditions of phosphorus dissolution, is improved
Reaction efficiency.Due to the solid solution phase (2CaOSiO of rich phosphorus2–3CaO·P2O5) soluble easily in water, it may occur that reaction is as follows:Lead to the pH value liter of ore pulp
It is high.When the pH value of ore pulp is excessively high, precipitation reaction can occur for the phosphate anion of dissolution, produce calcium phosphate precipitation.Therefore, it is selecting
The pH value that acid solution adjusts control ore pulp is added in selecting property leaching process, on the one hand promote the decomposition of solid solution, on the other hand
Inhibit the precipitating of phosphate anion.The present invention has selected cheap hydrochloric acid and/or nitric acid as the acid solution of addition.Work as mine
When the pH value of slurry is too low, in addition to the solid solution phase of rich phosphorus in steel slag, other iron-containing mineral facies can also dissolve simultaneously, cause to leach
The increase of iron concentration in liquid, is degrading Selectively leaching, is also unfavorable for extracting phosphate fertilizer from leachate.Optimizing research shows
The pH value of ore pulp, which should be controlled, is just able to achieve ideal Selectively leaching 3.0~4.5.It is isolated low by filtering after reaction
Phosphorus residue and phosphorous leachate.Due to the separated and dissolved of solid solution phase, low-phosphorous residue mainly by iron-containing Zeylanite phase and
Matrix phase composition.Iron, calcium, manganese element in residue are required components in steel-making, therefore low-phosphorous residue can be used as flux for metallurgy
It is used in sintering or steel-making.
(4) the phosphorous leachate that step (3) obtains mainly contains calcium ion, silicate ion and phosphate anion, and iron,
The concentration of manganese plasma is extremely low.It, can be by generating phosphorus because the solubility of synthos is very low in neutral or alkaline solution
The mode of sour calcium precipitate recycles phosphorus from leachate.Present invention employs the addition basic species such as calcium hydroxide and/or sodium hydroxide
The method of matter increases the pH value of leachate.Calcium ion and phosphate anion with the raising of pH of leaching solution, in leachate
Form calcium phosphate precipitation.When pH value is excessively high, phosphate anion and silicate ion all form precipitating, lead to isolated phosphorus
Silicone content is excessively high in hydrochlorate product and phosphorus content is lower, is not suitable as phosphate fertilizer.Optimizing research shows the pH when adjustment leachate
When value is 7.5~9.0, there is a large amount of white precipitate to generate in leachate, most phosphate anion precipitating, and silicate from
The rate of deposition of son is lower.The leachate for generating precipitating is stood, separates precipitating with solution.For further precipitation and separation, can adopt
Use centrifugal separation technology.Then, precipitating is dried to obtain phosphate product.P in the product2O5Mass fraction be more than 35%, it is more
Phosphorus in 97% has solubility in citric acid, and silicone content is lower.Because the main composition of phosphate fertilizer is calcium phosphate, the present invention is obtained
Phosphate product can be used directly as phosphate fertilizer.After extracting phosphate in phosphorous leachate, low-phosphorous leachate can return to step
Suddenly it is recycled in (3), reduces the consumption of water.
Specific technical solution is as follows:
A method of separation of phosphorus and phosphate fertilizer being prepared from dephosphorization steel slag, included the following steps:
(1) dephosphorization steel slag carries out oxidation processes in the molten state first, makes the mass fraction of FeO in steel slag lower than 8%,
After Slow cooling, crushing grinding is carried out to dephosphorization steel slag；
(2) the resulting dephosphorization steel slag of step (1) is mixed with aqueous solution and carries out Selectively leaching；Selectively leaching process
In, the pH value using hydrochloric acid and/or nitric acid solution control ore pulp is 3.0~4.5, after reaction, isolated low-phosphorous residue and is contained
Phosphorus leachate, low-phosphorous residue use in Ferrous Metallurgy；
(3) alkaline matter is added into the resulting phosphorous leachate of step (2), increases the pH value of leachate, until having big
The white precipitate of amount generates, and the precipitating after separation mainly contains synthos, can use directly as phosphate fertilizer.
In the step (1) during Slow cooling, when steel slag is cooled to 1100 DEG C from molten condition, cooling velocity is controlled
Lower than 10 DEG C/min.
In the step (1) after crushing grinding, the granularity of dephosphorization steel slag is less than 0.1mm.
In the step (2) during Selectively leaching, mechanical stirring is carried out to ore pulp.
The alkaline matter added in the step (3) is calcium hydroxide and/or sodium hydroxide.
In the step (3) after addition alkaline matter, the pH value of leachate is increased to 7.5~9.0.
Gravitational settling and/or centrifuge separation are utilized in the step (3), separation and Extraction precipitates from leachate.
Compared with prior art, the present invention has following advantageous effects:
Separation of phosphorus and the method for preparing phosphate fertilizer, specifically execution step and smelting from dephosphorization steel slag that the invention proposes a kind of
Golden principle is as follows:
(1) a kind of separation of phosphorus from steel slag proposed by the present invention and the method for preparing phosphate fertilizer have been achieved at low cost dephosphorization steel
The high-efficiency resource recycling of slag achieves the important breakthrough that phosphate fertilizer is prepared from metallurgical by-product, establishes green Ferrous Metallurgy
Process.
(2) present invention can make to be more than that 93% phosphorus is separated and is dissolved into solution in dephosphorization steel slag, and the dissolution rate of iron is lower than
0.1%, the separation of rich phosphorus solid solution phase and iron-bearing mineral phase in steel slag is farthest realized, ideal selectivity has been reached
It leaches.Low-phosphorous residue mainly contains the elements such as iron, calcium, manganese, can be used as flux for metallurgy and recycles in sintering or steel-making, realizes
The maximum value of valuable element in steel slag, has saved a large amount of Metallurgical resources, has reduced production cost.
(3) present invention utilizes Selectively leaching and chemical precipitation, be more than in dephosphorization steel slag 92% phosphorus with phosphate product
Form be recovered.P in the phosphate product2O5Mass fraction be more than 35%, and silicone content is lower, can be directly as phosphorus
Fertilizer uses.Therefore, the technology of the present invention can create huge economic benefit, save a large amount of phosphate rock resource, promote society can
Sustainable development.
(4) the technology of the present invention can be such that the dephosphorization steel slag generated in steel-making recycles in Ferrous Metallurgy process, realize " nothing
Waste residue " steel-making, not only promotes the energy-saving and emission-reduction of steel and iron industry, but also protect ecological environment.
(5) the technology of the present invention uses cheap hydrochloric acid or nitric acid, also uses common calcium hydroxide in industry
Or sodium hydroxide.Entire process flow all carries out under faintly acid and weak basic condition.The technology of the present invention has simple process, if
Standby to require low, high production efficiency, processing cost is low, has good market promotion prospect, can large-scale application in industrial production.
Detailed description of the invention
Fig. 1 is the separation of phosphorus and the process flow for preparing phosphate fertilizer in dephosphorization steel slag；
Fig. 2 is electron probe (EPMA) picture of steel slag 2 in embodiment 1；
Fig. 3 is the dissolution rate of each element in two kinds of steel slags in embodiment 1；
Fig. 4 is the photo of the phosphate fertilizer product prepared in embodiment 1；
Fig. 5 is the dissolution rate of each element in each steel slag in embodiment 2.
Specific embodiment
Below with reference to embodiment and attached drawing, the present invention is described in detail, but protection scope of the present invention is not by embodiment
It is limited with attached drawing.
Fig. 1 is that the separation of phosphorus is with the process flow for preparing phosphate fertilizer in dephosphorization steel slag, the process flow that the technology of the present invention proposes
As shown in the figure.
Embodiment 1
According to the composition of certain steel mill's dephosphorization steel slag, the present inventor has synthesized the steel slag of two kinds of different basicity, as shown in table 1.
To simulate the dephosphorization steel slag after oxidation processes, the iron in steel slag used in the present embodiment is all with Fe2O3Form exists, and does not deposit
In FeO.Firstly, dephosphorization steel slag is heated to 1550 DEG C of formation molten steel slags, then make molten steel slag with the cooling speed of 5 DEG C/min
Degree is cooled to 1100 DEG C, finally makes steel slag cooled to room temperature.
The main component (mass fraction/%) of the steel slag used in Example 1 of table 1
The mineral phase composition of dephosphorization steel slag is analyzed using electron probe (EPMA), as shown in Figure 2.Dephosphorization steel slag mainly wraps
Containing three kinds of mineral facies: the solid solution phase (2CaOSiO of rich phosphorus2–3CaO·P2O5), matrix phase (CaO-SiO2–Fe2O3) and iron magnesium
Spinel (Fe2O3–MgO–MnO).For steel slag 2, P in solid solution phase2O5Mass fraction be 18.9%, and Fe2O3Matter
Measuring score is only 0.8%.P2O5Content in matrix phase and Zeylanite phase is very low, illustrates that phosphorus is main in dephosphorization steel slag
It is enriched in solid solution phase.
By crusher and ball mill, slag crushing is ground, the particle size of steel slag is made to be less than 53um.1g steel slag is thrown
Enter into the aqueous solution of 400mL, while mechanical stirring is carried out to ore pulp using agitating paddle.During Selectively leaching, pH is utilized
The pH value of meter monitoring ore pulp, the temperature using thermostatic water bath control ore pulp is 25 DEG C.By automatic acid solution add-on system, to mine
The pH value that hydrochloric acid solution control ore pulp is added in slurry is 3.5.React 90min after, ore pulp is filtered separation, obtain residue with
Leachate.
Utilize the concentration of each element in ICP-AES measurement leachate.According to the component of steel slag, the concentration and leachate of element
Volume the dissolution rate of each element in steel slag has been calculated, as shown in Figure 3.Most phosphorus is all dissolved in two kinds of steel slags
It is separated in solution, wherein the dissolution rate of P elements has reached 96.1% in steel slag 2, and ferro element is almost difficult to dissolve out, dissolution
Rate is lower than 0.1%.Magnesium in steel slag, manganese, aluminium element dissolution rate well below P elements dissolution rate.This process realizes ideal
Selectively leaching.
Table 2 is the primary chemical composition of the residue of steel slag 2.Compared with the ingredient of steel slag 2, P in residue2O5Mass fraction
It significantly reduces, only 0.47%.Fe in residue2O3Content significantly improve, reached 58.72%.Because residue contains Fe2O3,
These valuable components of MnO and CaO, this residue can be used as flux for metallurgy and use in sintering and steelmaking process.
The primary chemical of the residue of steel slag 2 forms (mass fraction/%) in 2 embodiment 1 of table
Due to Selectively leaching, calcium ion, phosphate anion and silicate ion are mainly contained in obtained leachate.Table
3 be the concentration of each element in the leachate of steel slag 2.By addition calcium hydroxide solution, the pH value of leachate is made to be increased to 9.0,
There is a large amount of white precipitate to generate in leachate.Using gravitational settling and centrifuge separation, extracted from leachate produced
Precipitating.As shown in table 3, the concentration of phosphate anion is extremely low in the leachate after extracting precipitating, illustrates almost all of phosphorus
Element all enters in precipitating, realizes ideal recycling.
The concentration (mg/L) of each element in leachate after the leachate of steel slag 2 and extraction precipitate in 3 embodiment 1 of table
After precipitating drying, phosphate product has been obtained.Table 4 is the change of the phosphate product prepared from above-mentioned leachate
Learn composition.The phosphate product is mainly by CaO and P2O5It forms, wherein P2O5Mass fraction be 35.1%.Because phosphate produces
Silicone content is lower in product and most phosphorus has solubility in citric acid, it can be used directly as the phosphate fertilizer of high-quality.By whole
A process flow, about 95.9% phosphorus is recovered in the form of phosphate fertilizer in steel slag 2, has obtained phosphate fertilizer product as shown in Figure 4.
The chemical composition (mass fraction/%) of the phosphate product prepared in 4 embodiment 1 of table
Embodiment 2
According to the composition of certain steel mill's dephosphorization steel slag, the present inventor has synthesized the different dephosphorization steel slag of three kinds of phosphorus contents.Three kinds
The chemical composition of steel slag is as shown in table 5.To simulate the dephosphorization steel slag after oxidation processes, the iron in steel slag used in the present embodiment
All with Fe2O3Form exists, and does not contain FeO.Synthesis steel slag is heated to 1550 DEG C first and becomes molten condition, then makes to melt
Melt steel slag and slowly cool to 1000 DEG C with the cooling velocity of 4 DEG C/min, finally makes steel slag cooled to room temperature.
The main chemical compositions (mass fraction/%) of the steel slag used in 5 embodiment 2 of table
The mineral phase composition of dephosphorization steel slag has been determined using electron probe (EPMA).Each steel slag mainly includes three kinds of mineral
Phase: rich phosphorus solid solution phase (2CaOSiO2–3CaO·P2O5), matrix phase (CaO-SiO2–Fe2O3) and Zeylanite phase
(Fe2O3–MgO).With the increase of phosphorus content in steel slag, P in solid solution2O5Content increase.P in the solid solution of steel slag 32O5's
Mass fraction has reached 31.0%.P2O5Mass fraction in matrix phase and Zeylanite phase is lower than 0.9%, illustrates dephosphorization
Phosphorus in steel slag is mainly enriched in solid solution.
Using crusher and ball mill, slag crushing is ground, the particle size of steel slag is made to be less than 100um.By 1.5g steel
Slag is put into the aqueous solution of 300mL, while carrying out mechanical stirring to ore pulp using agitating paddle.During Selectively leaching, benefit
With the pH value of pH meter monitoring ore pulp, the temperature using thermostatic water bath control ore pulp is 25 DEG C.By automatic acid solution add-on system,
The pH value that hydrochloric acid solution control ore pulp is added into ore pulp is 3.5.After reacting 120min, ore pulp is filtered separation, is obtained
Residue and leachate.
The concentration of each element in leachate is determined using ICP-AES.According to the component of steel slag, the concentration and leaching of element
The volume of liquid calculates the dissolution rate of each element in steel slag.As shown in figure 5, dissolution of the phosphorus content of steel slag to P elements in steel slag
Rate influence is smaller, and P elements can reach 93% from the dissolution rate in steel slag, and ferro element is almost difficult to dissolve out, and dissolution rate is lower than
0.1%.As the phosphorus content of steel slag increases, the dissolution rate of calcium and element silicon is reduced, and each steel slag all realizes ideal selectivity
It leaches.
Table 6 is the chemical composition of the residue of each steel slag.Compared with the ingredient of original steel slag, P in residue2O5Content it is significant
It reduces, and Fe2O3Content significantly improve.For steel slag 1, P in steel slag after Selectively leaching2O5Mass fraction from 5.30%
It is reduced to 0.54%.Because these residues mainly contain Fe2O3, they can be used as flux for metallurgy in sintering and steel-making again
It utilizes.
The chemical composition (mass fraction/%) of the residue of each steel slag in 6 embodiment 2 of table
Due to Selectively leaching, calcium ion, phosphate radical and silicate ion are mainly contained in obtained leachate.Table 7 is
The concentration of each element in the mixing leachate that three kinds of steel slags obtain after leaching.By adding calcium hydroxide solution, the pH of leachate
Value is increased to 8.0, has a large amount of white precipitate to generate in leachate.Using gravitational settling and centrifuge separation, mentioned from leachate
Generated precipitating is got.As shown in table 7, the concentration for extracting phosphate anion in leachate after precipitating is dropped from 113.26mg/L
As low as 1.21mg/L, illustrates that almost all of phosphorus all enters in precipitating, realize ideal recycling.
The concentration (mg/L) of each element in leachate in 7 embodiment 2 of table after leachate and precipitation and separation
After precipitating drying, phosphate product has been obtained.Table 8 is the change of the phosphate product prepared from above-mentioned leachate
Learn composition.The phosphate product is mainly by CaO and P2O5It forms, wherein P2O5Mass fraction be 38.6%.Because phosphate produces
Silicone content is lower in product and most of phosphorus has solubility in citric acid, it can be used directly as the phosphate fertilizer of high-quality.By entire
Process flow, about 92.1% phosphorus is recovered in the form of phosphate fertilizer in steel slag 1.
The chemical composition (mass fraction/%) of the phosphate product prepared in 8 embodiment 2 of table
Claims (7)
1. a kind of separation of phosphorus from dephosphorization steel slag and the method for preparing phosphate fertilizer, characterized by the following steps:
(1) dephosphorization steel slag carries out oxidation processes in the molten state first, makes the mass fraction of FeO in steel slag lower than 8%, slowly
After cooling, crushing grinding is carried out to dephosphorization steel slag；
(2) the resulting dephosphorization steel slag of step (1) is mixed with aqueous solution and carries out Selectively leaching；During Selectively leaching,
PH value using hydrochloric acid and/or nitric acid solution control ore pulp is 3.0~4.5, after reaction, isolated low-phosphorous residue and phosphorous leaching
Liquid out, low-phosphorous residue use in Ferrous Metallurgy；
(3) alkaline matter is added into the resulting phosphorous leachate of step (2), increases the pH value of leachate, until having a large amount of
White precipitate generates, and the precipitating after separation mainly contains synthos, can use directly as phosphate fertilizer.
2. the separation of phosphorus according to claim 1 from dephosphorization steel slag and the method for preparing phosphate fertilizer, it is characterised in that: the step
Suddenly in (1) during Slow cooling, when steel slag is cooled to 1100 DEG C from molten condition, control cooling velocity is lower than 10 DEG C/min.
3. the separation of phosphorus according to claim 1 from dephosphorization steel slag and the method for preparing phosphate fertilizer, it is characterised in that: the step
Suddenly in (1) after crushing grinding, the granularity of dephosphorization steel slag is less than 0.1mm.
4. the separation of phosphorus according to claim 1 from dephosphorization steel slag and the method for preparing phosphate fertilizer, it is characterised in that: the step
Suddenly in (2) during Selectively leaching, mechanical stirring is carried out to ore pulp.
5. the separation of phosphorus according to claim 1 from dephosphorization steel slag and the method for preparing phosphate fertilizer, it is characterised in that: the step
Suddenly the alkaline matter added in (3) is calcium hydroxide and/or sodium hydroxide.
6. the separation of phosphorus according to claim 1 from dephosphorization steel slag and the method for preparing phosphate fertilizer, it is characterised in that: the step
Suddenly in (3) after addition alkaline matter, the pH value of leachate is increased to 7.5~9.0.
7. the separation of phosphorus according to claim 1 from dephosphorization steel slag and the method for preparing phosphate fertilizer, it is characterised in that: the step
Suddenly gravitational settling and/or centrifuge separation are utilized in (3), separation and Extraction precipitates from leachate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910915755.7A CN110526745A (en) | 2019-09-26 | 2019-09-26 | A method of separation of phosphorus and phosphate fertilizer is prepared from dephosphorization steel slag |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910915755.7A CN110526745A (en) | 2019-09-26 | 2019-09-26 | A method of separation of phosphorus and phosphate fertilizer is prepared from dephosphorization steel slag |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110526745A true CN110526745A (en) | 2019-12-03 |
Family
ID=68670226
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910915755.7A Pending CN110526745A (en) | 2019-09-26 | 2019-09-26 | A method of separation of phosphorus and phosphate fertilizer is prepared from dephosphorization steel slag |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110526745A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113930555A (en) * | 2021-10-18 | 2022-01-14 | 北京科技大学 | Molten steel slag supergravity dephosphorization method |
| CN115448759A (en) * | 2022-10-31 | 2022-12-09 | 安徽工业大学 | Method for producing liquid compound fertilizer |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104894308A (en) * | 2015-06-11 | 2015-09-09 | 重庆大学 | Method of removing phosphorus from steel slag to be recycled |
-
2019
- 2019-09-26 CN CN201910915755.7A patent/CN110526745A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104894308A (en) * | 2015-06-11 | 2015-09-09 | 重庆大学 | Method of removing phosphorus from steel slag to be recycled |
Non-Patent Citations (1)
| Title |
|---|
| CHUANMING DU ET.AL: "Recovery of Phosphorus from Modified Steelmaking Slag with High P2O5 Content via Leaching and Precipitation", 《ISIJ INTERNATIONAL》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113930555A (en) * | 2021-10-18 | 2022-01-14 | 北京科技大学 | Molten steel slag supergravity dephosphorization method |
| CN115448759A (en) * | 2022-10-31 | 2022-12-09 | 安徽工业大学 | Method for producing liquid compound fertilizer |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106676281B (en) | A kind of technique of Copper making liquid slag ore phase reconstruction Recovering Copper, iron | |
| CN100357470C (en) | Method for preparing ferro-titantium, steel and ferrovanadium from vanadium-titantium iron headings | |
| CN100497670C (en) | Process of fast reducing carbon-containing red mud nickel ore pellet to enriching nickel in a bottom rotating furnace | |
| CN107653381A (en) | The method of the production containing the slag melting and reducing of zinc and iron | |
| CN101073790B (en) | Reduction-mill concentration treatment for different-type red-clay nickel mine | |
| CN102912111B (en) | Treatment method of oolitic hematite containing phosphorus | |
| Zhou et al. | Extraction and separation of copper and iron from copper smelting slag: A review | |
| CN104894363B (en) | Method for using low-grade niobium concentrate to produce niobium-iron alloy and rare earth double sulfate salt | |
| EP4190924A1 (en) | Method for producing battery-grade nickel sulfate by means of laterite nickel ore | |
| CN102534271B (en) | Production method of vanadium-aluminum alloy | |
| CN110499400A (en) | A kind of converter slag high-efficiency resource recycling method | |
| CN101020958A (en) | Combined bottom rotating furnace-electric furnace process for treating red mud nickel ore to produce ferronickel | |
| CN110093506A (en) | Valuable metal high efficiency extraction and its minimizing processing method in germanic zinc leaching residue | |
| CN106755651A (en) | A kind of method reclaimed containing rare earth and/or niobium slag metallurgy one-step method | |
| CN101550483A (en) | Combined flow path processing method of laterite nickel | |
| CN102373329A (en) | Method for gathering nickel and iron from laterite-nickel ores | |
| CN107090551A (en) | A kind of method of the direct vanadium extraction of vanadium titano-magnetite | |
| CN110526745A (en) | A method of separation of phosphorus and phosphate fertilizer is prepared from dephosphorization steel slag | |
| CN106755655A (en) | A kind of recovery method for mixing the reduction of slag metallurgy melting | |
| CN106755653A (en) | A kind of method containing rare earth or the also original production of niobium slag metallurgy melting | |
| CN102212736B (en) | Method for preparing niobium microalloy steel by using low-niobium molten iron | |
| CN103074484B (en) | Comprehensive treatment method of oolitic hematite containing phosphorus and red mud | |
| RU2245371C2 (en) | Method of reworking red mud of alumina production process | |
| Wang et al. | Recovery of iron from lead slag with coal-based direct reduction followed by magnetic separation | |
| CN105316479A (en) | Red mud vanadium extracting and ore-blending sintering method |
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 |