CN106480310A - A kind of alkali-metal method in removing metallurgical dust sludge - Google Patents

Abstract

Alkali-metal method in a kind of open removing metallurgical dust sludge of the present invention, process flow is short, simple and easy to do, all using smelter mature equipment；The alkali-metal method of metallurgical dust sludge is removed using the present invention, horizontal moving bed reducing process is implemented, 20min～40min is processed under the conditions of 1100 DEG C～1300 DEG C sintering temperatures, the metallization iron charge that degree of metalization is more than 70% can be obtained, potassium, soda metal removal rate reach more than 90%, and zinc removal efficiency also reaches more than 96% simultaneously.

Description

A kind of alkali-metal method in removing metallurgical dust sludge

Technical field

The invention belongs to technical field of ferrous metallurgy, relate generally to a kind of metallurgical dust sludge and remove alkali-metal method.

Background technology

Traditional iron and steel enterprise all can produce substantial amounts of dirt mud solid waste in operations such as ironmaking, steel-making and steel rolling, accounts for total output of steel More than 10%.Often contain a large amount of ferrum in these dirt mud and there is very high recovery value, returning sintering as dispensing is still mesh Front topmost way of recycling, such as " method that a kind of ion dust mud contaning of CN102492833A is applied to sinter " etc., also have and join Enter the mode that pelletizing is reclaimed, for example " CN200410040020.8 steel-smelting sewage sludge starches the method for pelletizing production pelletizing " Deng, but there are a lot of problems in such method, because the physical parameter of dirt pug is larger with breeze materials variance, to sintering or pelletizing Production and technical indication and product quality impact are larger；Often contain more alkali metal (K, Na), zinc (Zn) in dirt pug simultaneously Deng harmful element, directly return raw material and a large amount of enrichments in blast furnace for the harmful element, impact blast furnace stable smooth operation and safety will be led to long Longevity, therefore be extremely limited using the dirt mud amount that such method recycles, enterprise can only be stored up using a large amount of places, if dealing with improperly, Not only caused the wasting of resources but also easily environment had been impacted.Therefore, how dirt mud solid wastes recycling more effectively to be reclaimed profit With becoming an important topic of iron and steel enterprise.

As long as it is true that the harmful elements such as the alkali metal in dirt pug, zinc can effectively be removed, it recycles approach will very Extensively.Presently, there are some treatment technologies for iron and steel enterprise's dirt mud dezincification, for example " CN101386913 rotary hearth furnace processes and contains The method that zinc powder dirt reclaims zinc oxide ", " CN104073649A iron content zinc powder dirt recycle technique ", " CN101092664 contains zinc The processing method of electric furnace dust ", is substantially and allocates the reducing agents such as coal into and make carbonaceous pelletizing, and then passes through rotary hearth furnace, shaft furnace etc. Be reduced into metallized pellet, after zinc reduction, enter flue gas, above-mentioned process dirt mud patent have in common that universal just for removing zinc, And actually all containing alkali metal and zinc in iron and steel enterprise's number of types of dirt mud solid waste simultaneously, the alkali metal in some dirt pugs contains Amount is even above zinc, but because the reduction temperature ratio of zinc compound is relatively low, usual dezincification is relatively easy, and alkali metal compound is (such as Alkali silicate) reduction temperature is generally higher, and relative difficulty is wanted in removing, ultimately results in alkali metal and still resides in metal in a large number Change in raw material.In addition the patent such as " a kind of zinc-iron-containing dust of CN101818264A, processing method of mud " discloses and utilizes high temperature Sludge pellet is reduced fusing by molten iron, makes reduced iron enter molten iron, and zinc enters flue gas, and other impurity enter the processing method of slag, But the dirt mud treating capacity of the method is limited, otherwise may impact hot metal composition and temperature, simultaneously this method generally add firefly for slugging Stone composition, the commonly used tank lining that easily causes corrodes.

To sum up, due to containing the harmful elements such as more alkali metal, zinc in dirt mud solid waste material, its recycling is extremely restricted, The also many removings just for zinc of some treatment technologies that presently, there are or method, and how to realize alkali-metal efficient removal to entering one It is great that step improves its recycling horizontal terms.

Technical scheme

The technical problem to be solved is to provide a kind of alkali-metal method in removing metallurgical dust sludge, to realize at 1100 DEG C Under the conditions of～1300 DEG C, alkali metal in efficient removal iron and steel enterprise dirt mud solid waste material, thus be greatly improved metallurgical dust sludge resource Using level.

For solving the above problems, the technical scheme is that：

1. in a kind of removing metallurgical dust sludge alkali-metal method it is characterised in that comprising the following steps：

(1). the chemical composition according to different metallurgical dust sludge carries out dispensing, and its composition includes dirt mud solid waste Glass Batch Quality percentage Ratio for 85%～95%, binding agent mass percent 0%～5%, slaked lime mass percent 0%～10%, remaining is additive； Control TFe >=40%, carbon content meets (C/O)=1.1～1.5 with the oxygen element total content mol ratio of iron oxides, zinc oxide, CaO and SiO₂Mass percent [CaO]/[SiO of composition₂]=1.0～2.0, alkali metal (K, Na) and Cl elemental mole ratios Meet (K+Na)/Cl=0.5～1.0；Described dirt mud solid waste batch includes blast furnace dedusting ash, gas mud, sintering dust separation ash, converter Dedusting ash, revolving furnace mud, iron scale, iron oxide red, coking, dust removing ash in two or more；Described binding agent be starch or One of other organic binder bonds；Described additive includes one of industrial calcium chloride, industrial hex-ammoniate；

(2). carry out reasonable dispensing according to each material chemical analysis, first will be fully broken to dirt mud solid waste batch, slaked lime solid material Broken roll, then put it into and in batch mixer, carry out mixed once；Desired amount of additive and binding agent are added to the water simultaneously It is made into aqueous solution, inject aqueous solution after solid material mix homogeneously and carry out secondary mixing；By final mixing after mix homogeneously Material is sent in ball press, is pressed into 10mm～30mm agglomerate, standby after agglomerate drying to biodiversity percentage composition≤3%；

(3). using horizontal moving bed reducing process, dirt walk block is processed under the conditions of 1100 DEG C～1300 DEG C sintering temperatures 20min～40min, obtains the iron charge that metallizes after high temperature reduction roasting, and alkali metal enters flue gas removing in a chloride-form, with When zinc also reduced removing in the lump.

The consumption of described slaked lime is according to CaO and SiO in described dirt mud solid waste batch₂The mass percent of composition determines, if Described CaO and SiO₂Mass percent [CaO]/[SiO of composition₂] be less than 1.0, then adding appropriate slaked lime makes [CaO]/[SiO₂] =1.0～2.0, otherwise need not add.

The CaCl of described industrial calcium chloride₂Weight/mass percentage composition >=90%, the MgCl of described industrial hex-ammoniate₂Weight/mass percentage composition >=45%.

Described moving bed reducing process includes rotary hearth furnace process or the similar technique of other principle.

The dirt mud solid waste material by reasonably combined iron and steel enterprise for the present invention, makes high ferro dirt mud complementary with high carbon dust mud element, fully profit The carbon itself being rich in dirt mud is it is not necessary to more additionally with addition of reducing agent, be pressed into pelletizing, further under the auxiliary of a small amount of binding agent Carry out subsequent treatment in conjunction with pyrogenic process direct-reduction technique, can the harmful element such as efficient removal alkali metal, and obtain metallization iron charge, Thus its recycling level is greatly improved.

In order that the metallization iron charge obtaining after processing reaches certain taste, dirt mud batch TFe content to be properly increased, simultaneously Take into account rationally a large amount of adapteds of dirt pug, substantially control the balance that can meet in TFe >=40% from the aspect of two.

Pass through to control carbon-to-oxygen ratio (C/O) simultaneously, make to join that carbon is suitably excessive in pelletizing, the reducing atmosphere of such pelletizing bed of material and temperature Degree is readily obtained guarantee, and test shows under the range of condition of (C/O)=1.1～1.5, and iron oxides and zinc impregnation in sludge pellet of the present invention is closed Thing can sufficiently be reduced.

In dirt mud solid waste material, removing zinc is reduced directly relatively easily by pyrogenic process, because reduction started temperature all phases of zinc compound To relatively low, be will also realize that by calculation of thermodynamics, ferrite (the ZnO Fe of zinc₂O₃), silicate (2ZnO SiO₂), oxygen Compound (ZnO) etc. and C direct reduction reactor can occur below at 1000 DEG C substantially, much studied and also indicated that and will realize The more thoroughly removing of zinc is relatively easy, and the reduction relative difficulty of alkali metal K, Na compound is many, such as silicate (K₂SiO₃、 Na₂SiO₃), carbonate (K₂CO₃、Na₂CO₃) etc., its direct-reduction is temperature required higher, and the especially reduction of silicate needs The high temperature wanting 1600 DEG C about just starts to react, and therefore removes alkali metal relative difficulty by high temperature reduction.And the present invention is due to adopting With chloride additive so as to remove the easy, in CaCl of change₂Or MgCl₂In the presence of, alkali metal compound can be with Its generation displacement reaction generates corresponding alkali metal chloride, and reaction is as follows (with K compound, CaCl₂As a example)：

K₂SiO₃+ C=2K+CO+SiO₂→K₂SiO₃+CaCl₂=2KCl+CaSiO₃

K₂CO₃+ 2C=2K+3CO → K₂CO₃+CaCl₂=2KCl+3CaCO₃

Thermodynamically the reaction Gibbs free energy of the latter is negative value always, and is easy to wave under alkali metal chloride hot conditionss Send out, add quick flow of flue gas purification, make the thermodynamics and kineticses condition of reaction all ideal, so that alkali is golden Belonging to also being capable of efficient removal.In order to ensure the abundant of reaction, the consumption of agent is accordingly suitably excessively added, research shows in alkali metal Under conditions of meeting (K+Na)/Cl=0.5～1.0 with Cl elemental mole ratios, optimal dealkalize effect can be obtained.

Test finds further, can play facilitation to the removing of alkali metal and zinc under a certain amount of CaO existence condition, Think that the compounds such as zinc ferrite, zinc silicate, alkali silicate can occur correlated response further with CaO, make The reduction reaction of these compounds or displacement reaction temperature have the trend reducing further, therefore properly increase basicity to removing alkali Metal and zinc are all favourable, control basicity in [CaO]/[SiO₂Removal efficiency highest during]=1.0～2.0 scope.And in major part dirt mud Natural alkalinity all higher, essentially without additionally condition can be met with addition of material containing CaO, when need on a small quantity with addition of when, Consider that slaked lime fully digests, have certain colloidal nature simultaneously concurrently, therefore select not using limestone with addition of slaked lime.

Sludge pellet of the present invention is used in horizontal moving bed class reducing process processing, can achieve alkali-metal efficient removal, The final metallization iron charge obtaining degree of metalization more than 70%, potassium, soda metal removal rate reach more than 90%.

Beneficial effects of the present invention：

1. the dirt mud solid waste material by reasonably combined iron and steel enterprise for the inventive method, can make full use of the carbon being wherein rich in, Metallization iron charge product need not finally be obtained again additionally with addition of reducing agent, pass through in addition to add appropriate additive and adjust suitably Basicity, makes the alkali metal compound of difficult reduction be replaced into volatile chloride removing, thus realizing the height to dirt mud solid waste material Effect dealkalize is processed, and its recycling level is greatly improved.

2. the inventive method process flow is short, simple and easy to do, all using smelter mature equipment；Using present invention removing The alkali-metal method of metallurgical dust sludge, implements, in horizontal moving bed reducing process under the conditions of 1100 DEG C～1300 DEG C sintering temperatures Process 20min～40min, the metallization iron charge that degree of metalization is more than 70% can be obtained, potassium, soda metal removal rate reach 90% More than, zinc removal efficiency also reaches more than 96% simultaneously.

Brief description

Fig. 1 is the inventive method schematic flow sheet.

Specific embodiment

Illustrate with reference to specific embodiment：

Embodiment 1

Dirt mud solid waste batch uses revolving furnace mud, blast furnace gas mud, blast furnace dedusting ash, blast furnace dust, iron scale, according to Its chemical composition carries out reasonably combined, controls TFe >=40% of dirt mud solid waste batch, control simultaneously carbon content and iron oxides, The oxygen element total content mol ratio of zinc oxide meets (C/O)=1.1, obtains dirt mud batch composition as shown in table 1.According to dirt It is [CaO]/[SiO that mud solid waste batch detection composition calculates basicity₂]=1.55, can not be with addition of slaked lime in the present embodiment.

The present embodiment uses industrial chlorinations calcium additive (CaCl₂Content 92%), according to the alkali metal of dirt mud solid waste batch Learn component molar ratio [(K+Na)/Cl]=0.5～1.0, can be calculated 100g dirt mud solid waste batch needs with addition of 2.7g～5.4g CaCl₂, converting as industrial calcium chloride is 2.9～5.9g.

By above-mentioned dirt mud solid waste Glass Batch Quality percentage ratio 90%, industrial calcium chloride mass percent 5%, starch quality percentage ratio 5% gets the raw materials ready.First roll fully broken for the solid materials such as dirt mud solid waste batch, then put it in batch mixer and carry out once Mixing；Desired amount of industrial calcium chloride and starch are added in suitable quantity of water simultaneously and be made into aqueous solution, treat solid material mix homogeneously Inject aqueous solution afterwards and carry out secondary mixing, after mix homogeneously send into final mixed material in ball press, be pressed into 10mm～30mm agglomerate, after agglomerate drying to moisture≤3%, described sludge pellet is used in rotary hearth furnace process, in roasting Reduction roasting 40min at 1150 DEG C of temperature, joins under carbon effect, iron oxides and zinc oxide are all reduced sufficiently in excess, And the alkali metal compound of hardly possible reduction is also replaced into volatile chloride, under quick flow of flue gas purification, volatilization Zinc and alkali metal chloride are constantly taken away by flue gas, thus realizing efficient removal, analyze after testing, finally obtain degree of metalization 81.2% metallization iron charge, and the removal efficiency of potassium is 92.4%, and sodium removal efficiency is 90.5%, and zinc removal efficiency also reaches simultaneously 97.5%.

Table 1 dirt mud solid waste batch chemical composition %

TFe	FeO	C	SiO2	CaO	K2O	Na2O	Zn
								45.13	31.78	16.16	4.37	6.76	1.35	0.62	2.31

Embodiment 2

According to embodiment 1 same steps, dirt mud solid waste batch uses blast furnace dedusting ash, gas mud, sintering dust separation ash, converter Dedusting ash, revolving furnace mud, iron scale, iron oxide red, coking, dust removing ash, carry out according to its chemical composition reasonably combined, control dirt mud TFe >=40% of solid waste batch, controls carbon content full with the oxygen element total content mol ratio of iron oxides, zinc oxide simultaneously Foot (C/O)=1.5.Detect that composition calculates basicity [CaO]/[SiO according to dirt mud solid waste batch₂]=0.92, passes through in the present embodiment to join Plus 0.5g～7.2g slaked lime can adjust basicity and reach 1.0～2.0 scopes.

The present embodiment uses industrial chlorinations magnesium additive (MgCl₂Content 45%), according to the alkali metal of dirt mud solid waste batch Learn component molar ratio [(K+Na)/Cl]=0.5～1.0, can be calculated 100g dirt mud solid waste batch needs with addition of 3.1g～6.2g MgCl₂, convert and need with addition of 6.9g～13.8g for industrial hex-ammoniate.

By above-mentioned dirt mud solid waste Glass Batch Quality percentage ratio 86%, slaked lime mass percent 4%, industrial hex-ammoniate percent mass Get the raw materials ready than 10%.First the solid materials such as dirt mud solid waste batch, slaked lime are carried out crushing and roll, then put it into batch mixing Carry out mixed once in machine；Desired amount of industrial hex-ammoniate is added in suitable quantity of water simultaneously and be made into additive solution, treat solidss Inject additive aqueous solution after material mix homogeneously and carry out secondary mixing, after mix homogeneously, final mixed material is sent into ball press In, it is pressed into 10mm～30mm pelletizing, after pelletizing drying to moisture≤3%, described sludge pellet is used for car-type reduction In furnace technology, reduction roasting 20min at 1300 DEG C of sintering temperature, joins under carbon effect, iron oxides and zinc oxygen in excess Compound is all reduced sufficiently, and the alkali metal compound of difficult reduction is also replaced into volatile chloride, in quick flow of flue gas Under purification, the zinc of volatilization and alkali metal chloride are constantly taken away by flue gas, thus realizing efficient removal, analyze after testing, The final metallization iron charge obtaining degree of metalization 93.2%, and the removal efficiency of potassium is 95.1%, and the removal efficiency of sodium is 92.0%, The removal efficiency of zinc reaches 99.2% simultaneously.

Embodiment 3

According to embodiment 1 same steps, dirt mud solid waste batch uses blast furnace dedusting ash, revolving furnace mud, is entered according to its chemical composition Row is reasonably combined, controls TFe >=40% of dirt mud solid waste batch, controls carbon content and iron oxides, zinc oxide simultaneously Oxygen element total content mol ratio meets (C/O)=1.3.Detect that composition calculates basicity according to dirt mud solid waste batch [CaO]/[SiO₂]=1.38, can not be with addition of slaked lime in the present embodiment.

Using industrial calcium chloride (CaCl in the present embodiment₂Content 90%) additive, according to the alkali metal of dirt mud solid waste batch Chemical composition mol ratio [(K+Na)/Cl]=0.5～1.0, can be calculated 100g dirt mud solid waste batch needs with addition of 3.4g～6.8g's CaCl₂, converting as industrial calcium chloride is 3.8g～7.6g.

By above-mentioned dirt mud solid waste Glass Batch Quality percentage ratio 94%, industrial calcium chloride mass percent 4.5%, polyacrylamide (PAM) mass percent 1.5% is got the raw materials ready.First the solid materials such as dirt mud solid waste batch are carried out crushing and roll, then by it Put into and in batch mixer, carry out mixed once；Simultaneously water-soluble by being made in desired amount of industrial calcium chloride and PAM addition suitable quantity of water Liquid, injects aqueous solution after solid material mix homogeneously and carries out secondary mixing, after mix homogeneously send into final mixed material In ball press, it is pressed into 10mm～30mm pelletizing, after pelletizing drying to moisture≤3%, described sludge pellet is used for turning bottom In furnace technology, reduction roasting 30min at 1250 DEG C of sintering temperature, joins under carbon effect, iron oxides and zinc oxygen in excess Compound is all reduced sufficiently, and the alkali metal compound of difficult reduction is also replaced into volatile chloride, in quick flow of flue gas Under purification, the zinc of volatilization and alkali metal chloride are constantly taken away by flue gas, thus realizing efficient removal, analyze after testing, The final metallization iron charge obtaining degree of metalization 73.9%, and the removal efficiency of potassium is 93.1%, and the removal efficiency of sodium is 90.3%, The removal efficiency of zinc also reaches 97.2% simultaneously.

Claims (1)

1. in a kind of removing metallurgical dust sludge alkali-metal method it is characterised in that comprising the following steps：

(1). the chemical composition according to different metallurgical dust sludge carries out dispensing, and its composition includes dirt mud solid waste Glass Batch Quality percentage Ratio for 85%～95%, binding agent mass percent 0%～5%, slaked lime mass percent 0%～10%, remaining is additive； Control TFe >=40%, carbon content meets (C/O)=1.1～1.5 with the oxygen element total content mol ratio of iron oxides, zinc oxide, CaO and SiO₂Mass percent [CaO]/[SiO of composition₂]=1.0～2.0, alkali metal (K, Na) and Cl elemental mole ratios Meet (K+Na)/Cl=0.5～1.0；Described dirt mud solid waste batch includes blast furnace dedusting ash, gas mud, sintering dust separation ash, converter Dedusting ash, revolving furnace mud, iron scale, iron oxide red, coking, dust removing ash in two or more；Described binding agent be starch or One of other organic binder bonds；Described additive includes one of industrial calcium chloride, industrial hex-ammoniate；

(2). carry out reasonable dispensing according to each material chemical analysis, first will be fully broken to dirt mud solid waste batch, slaked lime solid material Broken roll, then put it into and in batch mixer, carry out mixed once；Desired amount of additive and binding agent are added to the water simultaneously It is made into aqueous solution, inject aqueous solution after solid material mix homogeneously and carry out secondary mixing；By final mixing after mix homogeneously Material is sent in ball press, is pressed into 10mm～30mm agglomerate, standby after agglomerate drying to biodiversity percentage composition≤3%；

(3). using horizontal moving bed reducing process, dirt walk block is processed under the conditions of 1100 DEG C～1300 DEG C sintering temperatures 20min～40min, obtains the iron charge that metallizes after high temperature reduction roasting, and alkali metal enters flue gas removing in a chloride-form, with When zinc also reduced removing in the lump.