CN109468467A - A kind of steel and iron industry solid waste valuable metal recovery method - Google Patents
A kind of steel and iron industry solid waste valuable metal recovery method Download PDFInfo
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- CN109468467A CN109468467A CN201811629371.0A CN201811629371A CN109468467A CN 109468467 A CN109468467 A CN 109468467A CN 201811629371 A CN201811629371 A CN 201811629371A CN 109468467 A CN109468467 A CN 109468467A
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
- C22B7/001—Dry processes
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B1/00—Preliminary treatment of ores or scrap
- C22B1/14—Agglomerating; Briquetting; Binding; Granulating
- C22B1/16—Sintering; Agglomerating
- C22B1/216—Sintering; Agglomerating in rotary furnaces
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B1/00—Preliminary treatment of ores or scrap
- C22B1/14—Agglomerating; Briquetting; Binding; Granulating
- C22B1/24—Binding; Briquetting ; Granulating
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B1/00—Preliminary treatment of ores or scrap
- C22B1/14—Agglomerating; Briquetting; Binding; Granulating
- C22B1/24—Binding; Briquetting ; Granulating
- C22B1/248—Binding; Briquetting ; Granulating of metal scrap or alloys
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B19/00—Obtaining zinc or zinc oxide
- C22B19/04—Obtaining zinc by distilling
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B19/00—Obtaining zinc or zinc oxide
- C22B19/30—Obtaining zinc or zinc oxide from metallic residues or scraps
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B5/00—General methods of reducing to metals
- C22B5/02—Dry methods smelting of sulfides or formation of mattes
- C22B5/10—Dry methods smelting of sulfides or formation of mattes by solid carbonaceous reducing agents
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
- C22B7/02—Working-up flue dust
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Abstract
The invention discloses a kind of steel and iron industry solid waste valuable metal recovery methods, are related to metallurgical solid waste technical field of resource utilization.Internal layer pelletizing is made in metallurgical solid waste powder A by the present invention, wherein ω in metallurgical solid waste powder AZnThe molar ratio of >=3%, C and Zn are k: 1, and 1≤k≤5；Metallurgical solid waste powder material B is wrapped up to internal layer pelletizing surface again and forms clad；Pelletizing after cladding is placed in grate kiln and preheated, roasted, so that the metallic zinc in pelletizing restores evaporation, the metallic zinc in rotary kiln is recycled by air extractor.The present invention makes clad play barrier and thermally conductive effect to internal layer pelletizing using this method, one side clad can form the atmosphere of a reproducibility at internal layer pelletizing, another aspect clad can make internal layer pelletizing keep higher temperature, and then promote the reduction recycling of the heavy metals such as zinc in internal layer pelletizing.
Description
Technical field
The present invention relates to metallurgical solid waste technical field of resource utilization, have more specifically to a kind of steel and iron industry solid waste
Valence metal recovery processes.
Background technique
There is a large amount of metallurgical solid waste in iron and steel metallurgical industry at present, wherein blast furnace dedusting ash is one of them, blast furnace
The heavy metals such as Fe, C and Zn rich in, Pb in dedusting ash have preferable comprehensive reutilization value；And converter dust
In, containing a large amount of Fe element (TFe >=50%), the economic benefit of recycling is also very significant；In addition also containing big in electric furnace ash
The heavy metal element of amount, is sintered the Fe element of amount in ash, and recovery value is huge.
For metallurgical solid waste, since metal recovery rate is lower in metallurgical solid waste, many iron and steel enterprise's selections are directly outer at present
Row stacks, and this kind of processing mode will lead to serious environmental pollution and the wasting of resources；Ye You iron and steel enterprise consolidates partial metallurgical
Useless be put into iron-smelting raw material is recycled, but is to be handled subsequent and can brought to blast furnace ironmaking larger by this kind of mode
Burden.There are many related researchers to conduct a research the processing of metallurgical solid waste, at present the more metallurgical solid waste of mainstream
Processing method is coal-pressing ball method, main operational principle be will be mixed into using forming press-roller of a pair to roller blast furnace dedusting ash or
The powder raw material of converter dust-removing ash is pressed into pelletizing of corresponding size, but there is also more problem, a sides for coal-pressing ball method
The manufacturing process of face cooled agglomerated pellet needs individually to match carbon, increases processing cost；Another aspect coal-pressing ball intensity is poor, smelts
Journey metallurgical performance is poor.
Through retrieving, denomination of invention are as follows: using rotary kiln recycling zinc method and device thereof (application number:
201210369145.X, the applying date: 2012.09.29), this application is incorporated electric furnace ash, anthracite and gas in blast furnace ash
Mud；Above-mentioned mix is sent to rotary kiln high temperature and is burnt, the zinc in mix is made to gasify to form gasification zinc；To gasify zinc
Expansion chamber is sucked, cooling while removes dust therein；Then gasification zinc continues forward and enters surface air cooler, fast cooling,
And gasification zinc is made to generate zinc oxide in conjunction with the oxygen in air.This application can make blast furnace ash, gas mud, electricity to a certain extent
Zinc in ashes is recycled, but it not only needs in addition to match carbon, improves cost recovery, and recovery efficiency is lower.
Summary of the invention
1. technical problems to be solved by the inivention
It is an object of the invention to overcome in the prior art, metallurgical solid waste carries out metal recovery during metal recovery utilization
The low problem of rate provides a kind of steel and iron industry solid waste valuable metal recovery method, by by the metallurgical solid waste system of high-carbon zinc-rich
It is overmolding to clad in internal layer pelletizing outer surface at internal layer pelletizing, then by metallurgical solid waste, then pelletizing after the cladding is roasted
It realizes the reduction evaporation of heavy metal, and then improves the rate of recovery of metal in metallurgical solid waste.
2. technical solution
In order to achieve the above objectives, technical solution provided by the invention are as follows:
Internal layer pelletizing is made in metallurgical solid waste powder A by a kind of steel and iron industry solid waste valuable metal recovery method of the invention,
Wherein ω in metallurgical solid waste powder AZnThe molar ratio of >=3%, C and Zn are k: 1, and 1≤k≤5；Again by metallurgical solid waste powder material B packet
It wraps up in internal layer pelletizing surface and forms clad；Pelletizing after cladding is placed in grate kiln and preheated, roasted, so that
Metallic zinc in pelletizing restores evaporation, is recycled by air extractor to the metallic zinc in rotary kiln.
Preferably, specific steps are as follows:
Step 1: ingredient:
According to Zn and C content in different types of metallurgical solid waste, metallurgical solid waste progress ingredient is obtained into metallurgical solid waste A, so that
ω in metallurgical solid waste AZnThe molar ratio of >=3%, C and Zn are k: 1, wherein 1≤k≤5；Metallurgical solid waste progress ingredient is obtained again metallurgical
ω in solid waste B, metallurgical solid waste BFe>=30%；
Step 2: broken:
Metallurgical solid waste A and metallurgy solid waste B are crushed respectively, metallurgy solid waste powder A and metallurgical solid waste powder are made respectively
Expect B；
Step 3: pelletizing:
(1) on disc balling machine be added metallurgy solid waste powder A, Xiang Yejin solid waste powder A spray water, disc balling machine into
Internal layer pelletizing is made in row pelletizing；
(2) metallurgical solid waste powder material B is added in disc balling machine, water spray is so that metallurgical solid waste powder material B is adhered to metallurgy admittedly
The useless surface powder A forms clad；
Step 4: pellet roasting
(1) pelletizing after cladding is placed on drying grate and carries out drying and preheating；
(2) pelletizing after drying and preheating, which enters in rotary kiln, is roasted；
Step 5: metal recovery
(1) air extractor is provided on rotary kiln, after pelletizing is fired, the zinc in internal layer pelletizing is waved as a vapor
Hair, is then trapped by air extractor, realizes effective recycling of zinc；
(2) it returns and is sintered after being crushed the pelletizing after roasting；Or magnetic separation is carried out after being crushed the pelletizing after roasting, recycling roasting
Fe after burning in pelletizing3O4Or metallic iron.
Preferably, the molar ratio of C and Zn is k: 1 in metallurgical solid waste A, and 1.5≤k≤3.
Preferably, ω in metallurgical solid waste APb>=2%.
Preferably, in shattering process, metallurgical solid waste A and metallurgy solid waste B are crushed in sample pulverizer respectively,
Metallurgy solid waste powder A and metallurgical solid waste powder material B are made respectively, wherein the average particle size of metallurgical solid waste powder A is greater than metallurgical solid waste
The average particle size of powder material B.
Preferably, in balling process, the spherical radius of internal layer pelletizing is D1, clad with a thickness of D2, f=D1/D2,
Control 2≤f≤4.
Preferably, during pellet roasting, the maturing temperature in rotary kiln is 1050~1300 DEG C.
Preferably, in metal recovery process, air extractor is connected with cooling device, and cooling device cools back zinc
It receives.
Preferably, metallurgical solid waste powder A partial size is 60%~70% less than the mass percent of 150 mesh, metallurgical solid waste powder
Expect that B partial size is greater than 70% less than the mass percent of 300 mesh.
Preferably, metallurgical solid waste A includes blast furnace ash and/or electric furnace ash；Metallurgical solid waste B includes converter ash and/or sintering ash.
3. beneficial effect
Using technical solution provided by the invention, compared with existing well-known technique, there is following remarkable result:
Internal layer pelletizing is made in metallurgical solid waste powder A by a kind of steel and iron industry solid waste valuable metal recovery method of the invention,
Wherein ω in metallurgical solid waste powder AZnThe molar ratio of >=3%, C and Zn are k: 1, and 1≤k≤5；Again by metallurgical solid waste powder material B packet
It wraps up in internal layer pelletizing surface and forms clad；Pelletizing after cladding is placed in grate kiln and preheated, roasted, so that
Metallic zinc in pelletizing restores evaporation, is recycled by air extractor to the metallic zinc in rotary kiln；This method to coat
Layer plays barrier and thermally conductive effect to internal layer pelletizing, and one side clad can form a reproducibility at internal layer pelletizing
Atmosphere, another aspect clad can make internal layer pelletizing keep higher temperature, and then promote the huge sum of money such as zinc in internal layer pelletizing
The reduction of category is recycled.
Detailed description of the invention
Fig. 1 is a kind of flow diagram of steel and iron industry solid waste valuable metal recovery method of the invention；
Fig. 2 is a kind of schematic device of steel and iron industry solid waste valuable metal recovery method of the invention；
Fig. 3 is covered effect schematic diagram of the invention.
Label declaration in schematic diagram:
100, internal layer pelletizing；200, clad；300, disc balling machine；400, drying grate；500, rotary kiln；501, it is evacuated
Device.
Specific embodiment
Hereafter detailed description of the present invention and example embodiment are more fully understood in combination with attached drawing.
Embodiment 1
As shown in Figures 1 to 3, a kind of steel and iron industry solid waste valuable metal recovery method of the invention, by metallurgical solid waste powder A
Internal layer pelletizing 100 is made, wherein ω in metallurgical solid waste powder AZnThe molar ratio of >=3%, C and Zn are k: 1, and 1≤k≤5；Again will
Metallurgical solid waste powder material B wraps up to 100 surface of internal layer pelletizing and forms clad 200；Pelletizing after cladding is placed in drying grate 400- to return
It preheated, roasted in rotary kiln 500, so that the metallic zinc in pelletizing restores evaporation, by air extractor 501 to rotary kiln 500
Interior metallic zinc is recycled.In balling process, metallurgical solid waste powder material B forms clad and is wrapped in metallurgical solid waste powder A
The outer surface of layer pelletizing, clad can play barrier and thermally conductive effect to internal layer pelletizing, one side clad can including
The atmosphere of a reproducibility is formed at layer pelletizing, in addition roll cover can make internal layer pelletizing keep higher temperature, in turn
Promote the reduction recycling of the heavy metals such as zinc in internal layer pelletizing.In addition, ω in internal layer pelletizing 100Pb>=2%, it can be simultaneously to rich lead
Lead in metallurgical solid waste is effectively recycled.
Contain ferriferous oxide, ω in metallurgical solid waste powder material BFe>=30%；Metallurgical solid waste powder A is by blast furnace ash and/or electric furnace
Ash composition；Metallurgical solid waste powder material B is made of converter ash and/or sintering ash；In the present embodiment, metallurgical solid waste powder A is by blast furnace ash
It is formed with electric furnace ash, metallurgical solid waste powder material B is made of converter ash and sintering ash.
The specific steps of this method, the pelletizing use process prepared and its explanation are as follows:
Step 1: ingredient:
The blending process is the blending process of internal layer pelletizing 100 and clad 200, and metallurgical solid waste A is to prepare internal layer pelletizing
Raw material used in 100, metallurgical solid waste B are to prepare raw material used in clad 200.
Different metallurgical solid wastes is chosen from each production procedure of iron and steel enterprise, obtains Zn in different metallurgical solid wastes by examining
And metallurgical solid waste progress ingredient is obtained metallurgical solid waste A, matched by C content further according to Zn and C content in different types of metallurgical solid waste
The foundation of material is to make ω in metallurgical solid waste AZn>=3%, ωPbThe molar ratio of >=2%, C and Zn are k: 1, wherein 1≤k≤5；Again will
Metallurgical solid waste carries out ingredient and obtains metallurgical solid waste B.
In the present embodiment, selected metallurgical solid waste A is as shown in table 1, the metallurgical solid waste B of the present embodiment include converter ash and
ω in sintering ash, converter ash and sintering ashTFeAlkali metal element quality hundred in respectively 56.30% and 38.35%, metallurgical solid waste B
Point content is no less than 2%.
1 metallurgy solid waste A component list (mass percent) of table
In the present embodiment, the molar ratio of C and Zn are 3: 1, and above-mentioned blast furnace ash and electric furnace are taken according to the molar ratio of the C and Zn
Ash is mixed, and it is stand-by to be made into metallurgical solid waste A；It takes above-mentioned converter ash and sintering ash to be mixed again, is made into metallurgical solid waste B and waits for
With.
It should be noted that metallurgy solid waste A prepares raw material used in internal layer pelletizing 100 as subsequent in blending process,
Metallurgical solid waste A needs to meet the condition of high-carbon zinc-rich, and its object is to utilize C or C reduction generated in metallurgical solid waste
Property gas the Zn in metallurgical solid waste is fully restored, make the Zn in metallurgical solid waste A obtain sufficiently restoring to realizing back
It receives；And the molar ratio of C and Zn is 1: 1 to 5: 1 in metallurgical solid waste A, its object is to keep the excess of C, the excessive of C on the one hand can
To guarantee that the Zn in internal layer pelletizing 100 is sufficiently restored；On the other hand in can increasing after more C formation reducibility gas
Pressure in layer pelletizing 100, can promote Zn reduction volatilization from internal layer pelletizing 100；In addition, excessive C is also in metallurgical solid waste A
For restoring the metallic element in other metallurgical solid wastes, as contained ferriferous oxide, ω in metallurgical solid waste BFe>=30%, internal layer pelletizing
100 CO generated can realize the recycling to Fe in clad 200；In addition contain suitable alkali metal in clad 200
Element has the function of being catalyzed ferriferous oxide reduction.
Step 2: broken
Metallurgical solid waste powder A and metallurgical solid waste powder material B are obtained by metallurgical solid waste A and metallurgy solid waste B is broken respectively, and metallurgy is solid
The average particle size of useless powder A is greater than the average particle size of metallurgical solid waste powder material B；Specifically, metallurgical solid waste powder of the partial size less than 150 mesh
Expect that A mass percent is 60%~70%, partial size is greater than 70% less than the metallurgical solid waste powder material B mass percent of 300 mesh, this reality
It applies in example preferably, partial size is that the metallurgical solid waste powder A mass percent of 200 mesh~150 mesh is 50%~65%, is specifically
55%；Partial size is 80% less than the mass percent of the metallurgical solid waste powder material B of 300 mesh in clad 200.
Metallurgical solid waste A and metallurgy solid waste B are respectively placed in pulverizer and are crushed, metallurgical solid waste A in the present embodiment
3~4min is crushed in pulverizer, obtained metallurgy solid waste powder A is spare after screening, so that metallurgy solid waste powder A reaches above-mentioned
Granularity requirements；Metallurgical solid waste B is crushed to 8~12min in pulverizer again, obtained metallurgy solid waste powder material B is spare after screening, so that
Metallurgical solid waste powder material B reaches above-mentioned granularity requirements.
Control for metallurgical solid waste powder A and metallurgical solid waste powder material B granularity, it should be noted that by metallurgical solid waste powder
The biggish purpose of size controlling of material A is in order to increase the gap in internal layer pelletizing 100 between metallurgical solid waste powder A, so that smelting
Reducing atmosphere caused by C in golden solid waste powder A can be sufficient filling in gap, to promote the reaction of reduction reaction
Interface as much as possible from solid-solid transition to vapor solid, and then improve the reduction reaction rates of the heavy metals such as zinc with react
Degree.And be the lesser reason of size controlling of metallurgical solid waste powder material B: the main purpose that clad 200 is arranged is two
Aspect, on the one hand, clad 200 has the function of barrier, and clad 200 is by the CO in barrier internal layer pelletizing 100 to extending out
It dissipates, so that internal layer pelletizing 100 is always maintained at the atmosphere of a high concentration CO, is conducive to the huge sum of money such as zinc in internal layer pelletizing 100
The effective reduction belonged to, so clad 200 can be improved to internal layer pelletizing in the partial size for reducing metallurgical solid waste powder material B to a certain extent
The barrier action of the reducibility gas such as CO in 100；On the other hand, clad 200 has the function of thermally conductive, and clad 200 is used for
Inside the heat transfer in rotary kiln to internal layer pelletizing 100, then the reducing atmosphere for cooperating internal layer pelletizing 100 to be formed by,
To realize the atmosphere of 100 high temperature strong reducing property of internal layer pelletizing, the heavy metals such as zinc in internal layer pelletizing 100 are further promoted
Reduction, and the partial size for reducing metallurgical solid waste powder material B helps to improve clad by strengthening the contact between microcosmic upper particle
200 heat-conducting effect macroscopically.
Step 3: pelletizing
A, 100 pelletizing of internal layer pelletizing
Metallurgical solid waste powder A is added in disc balling machine, and is sprayed water to disc balling machine, metallurgical solid waste powder A is in circle
Balling-up in disk pelletizer, gradually grows up to form parent nucleus；And rear surface parent nucleus overly moist continues to adhere to metallurgical solid waste powder A, is formed
The sphere diameter of internal layer pelletizing 100, internal layer pelletizing 100 is controlled in 4~9mm；
B, 200 pelletizing of clad
After internal layer pelletizing 100 prepares, metallurgical solid waste powder material B is added in disc balling machine, and is sprayed to disc balling machine
Water so that metallurgical solid waste powder material B is adhered to 100 surface of internal layer pelletizing, and is constantly grown up in disc balling machine, metallurgical solid waste
Powder material B forms clad 200 on 100 surface of internal layer pelletizing, and the sphere diameter of clad 200 is 10~16mm.
It should be noted that the spherical radius of internal layer pelletizing 100 is D1, clad 200 with a thickness of D2, f=D1/D2,
During using disc balling machine pelletizing, 2≤f≤4 are controlled；And test hair for a long time is passed through by applicant research team
Now, above-mentioned f and the partial size of metallurgy solid waste powder material B used in clad 200 are closely related, when the grain of metallurgical solid waste powder material B
Diameter gets over hour, the corresponding thickness D for reducing clad 2002, be conducive to the recycling to heavy metal in metallurgical solid waste.Metallurgical solid waste powder
The particle diameter distribution situation and f for expecting B substantially conform to the relationship:Wherein, α is partial size in clad 200 less than 300 purposes
The mass percent of metallurgical solid waste powder material B, q are empirical value, and value is 0.02~0.03.In the present embodiment, in clad 200
Partial size is that 80%, q takes 0.03 less than the mass percent α of the metallurgical solid waste powder material B of 300 mesh, then f=3, i.e. internal layer pelletizing 100
Spherical radius D1For the thickness D of clad 20023 times.In the present embodiment, the spherical radius D of internal layer pelletizing 1001For
4.5mm, the thickness D of clad 2002For 1.5mm.
Step 4: pellet roasting
A, the pelletizing after cladding is placed on drying grate and carries out drying and preheating；
B, the pelletizing after drying and preheating, which enters in rotary kiln, is roasted, and the maturing temperature in rotary kiln is 1050~1300
DEG C, the maturing temperature in the present embodiment in rotary kiln is 1100 DEG C.
Step 5: metal recovery
A, air extractor is provided on rotary kiln, after pelletizing is fired, the zinc in internal layer pelletizing 100 is as a vapor
Volatilization, is trapped by air extractor, and then subsequent cooling device carries out cooling recycling to it, realizes effective recycling of zinc；
B, the pelletizing after roasting is handled；By the pelletizing after roasting it is broken after return to sintering, realize Fe element into
The recycling of one step；Or magnetic separation is carried out after being crushed the pelletizing after roasting, the Fe after magnetic separation recovery roasts in pelletizing3O4Or metallic iron,
Fe is recycled in the present embodiment by the way of magnetic separation.Each metal recovery rate record is shown in Table 2~3 in the present embodiment.
Comparative example 1
Ingredient, shattering process and subsequent metal recovery process in this comparative example is substantially the same manner as Example 1, no
It is with place, in the present embodiment the processing mode in embodiment 1 is not used for metallurgical solid waste, but by different types of smelting
It is mixed after golden solid waste ingredient, mixed mixture is put into rotary kiln and is roasted, 1100 DEG C of maturing temperature, then
Zinc is recycled in such a way that zinc vapor condensing traps, Fe is recycled by way of fired slags crushing-magnetic selection, respectively
Its rate of recovery is calculated after metal recovery and is recorded as shown in table 2.
Comparative example 2
Ingredient, shattering process and subsequent metal recovery process in this comparative example is substantially the same manner as Example 1, no
It is with place, in the present embodiment the processing mode in embodiment 1 is not used for metallurgical solid waste, but by different types of smelting
It is mixed after golden solid waste ingredient, mixed mixture is directly placed into disc balling machine and carries out pelletizing, pelletizing partial size is
12mm, green-ball enters drying grate preheating is dried after pelletizing, then enters in rotary kiln and is roasted, maturing temperature 1100
℃.Zinc is recycled in such a way that zinc vapor condensing traps then, Fe is carried out by way of fired slags crushing-magnetic selection
It recycles, its rate of recovery is calculated after each metal recovery and records as shown in table 2.
Table 2 is metallurgical fixed-end forces mode and each embodiment metal recovery rate in comparative example 1, comparative example 2 and embodiment 1
Record case.
The metallurgical fixed-end forces mode of table 2 and metal recovery rate record sheet
Table 2 is analyzed, embodiment 1 and two comparative examples are compared it can be found that being compared to two comparisons
Metallurgy fixed-end forces mode used by example, after embodiment 1 handles metallurgical solid waste using the pelletizing after cladding, metal recovery rate
It is higher.By prolonged Test Summary and seminar in repeatedly group is held, applicant thinks that its reason is:
It is compared to mode directly baking mixed in comparative example 1, embodiment 1 is according to element in variety classes metallurgy solid waste
The metallurgical solid waste of high-carbon zinc-rich is prepared into internal layer pelletizing 100 by the difference of content, is wrapped up outside internal layer pelletizing 100 more tight
Close clad 200, clad 200 can have the function of thermally conductive and barrier to internal layer pelletizing 100, and clad 200, which has, leads
Heat effect, the heat in rotary kiln can be transferred in internal layer pelletizing 100, by reacting meeting after the C heating in internal layer pelletizing 100
A large amount of CO is generated, then part CO and ZnO, which reacts, generates zinc fume；In addition clad 200 has barrier action, can
It is entered in internal layer pelletizing 100 with the atmosphere for obstructing extraneous, ensure that has stronger reduction in this way in internal layer pelletizing 100
Property atmosphere, in the high temperature strong reducing property atmosphere of internal layer pelletizing 100, the ZnO in internal layer pelletizing 100 can be sufficiently reduced to by C
Zinc fume, and the hyperbaric environment formed in internal layer pelletizing 100 is also beneficial to the formation of reducing atmosphere in internal layer pelletizing 100,
Promote the reduction of ZnO and lead oxides.
In addition it is worth noting that, Fe content in clad 200 is improved, the recycling of Fe in metallurgical solid waste not only can be improved
Efficiency, in addition it can enhance the heat-conducting effect of clad 200.When the reducibility gas in internal layer pelletizing 100 diffuses to cladding
When at layer 200, there is reduction to the ferriferous oxide in clad 200, it can be by Fe2O3It is reduced to Fe3O4Or by iron oxygen
Compound is reduced to metallic iron, these reactions occurred on clad 200 can make clad 200, and closely structure is sent out originally
Life destroys, so that the heavy metals steam such as zinc in internal layer pelletizing 100 is overflowed from pelletizing, so that the heavy metal element is through receiving
Collect available recycling；And the Fe of generation is restored on clad 2003O4With metallic iron pellet roasting it is complete after can directly into
Row crushing-magnetic selection is recycled, or enters the recycling that sintering process carries out Fe, so using the technical solution Fe in embodiment 1
Recovery efficiency with higher.
And technical solution used by comparative example 1 and comparative example 2 is reviewed, directly made by metallurgical solid waste or by metallurgical solid waste
Ball is put into rotary kiln and is directly roasted, although in rotary kiln and reducing atmosphere, guaranteeing to fire in rotary kiln
That burns is normally carried out, and the reducing degree of atmosphere is limited by very large, and in addition the temperature in rotary kiln is relatively low, to metallurgy
Heavy metallic oxide in solid waste is unable to reach such as the reduction effect in embodiment 1.
Embodiment 2
The present embodiment substantially with embodiment 1, the difference is that, in the internal layer pelletizing 100 of the present embodiment, partial size 200
The metallurgical solid waste powder A mass percent of mesh~150 mesh is 60%, metallurgical solid waste powder of the partial size less than 300 mesh in clad 200
The mass percent for expecting B is also 80%, and embodiment improves the quality of partial size metallurgy solid waste powder A big in internal layer pelletizing 100
Percentage；Pelletizing then, pellet roasting and metal recovery step are same as Example 1.Each metal recovery rate in the present embodiment
Record is shown in Table 3.
Embodiment 3
The present embodiment substantially with embodiment 1, the difference is that, in the clad 200 of the present embodiment, partial size is less than 300
The mass percent of purpose metallurgy solid waste powder is 90%.Partial size is the metallurgical solid waste of 200 mesh~150 mesh in internal layer pelletizing 100
Powder A is still 55%, and the present embodiment is intended to improve in clad 200 partial size less than the matter of the metallurgical solid waste powder material B of 300 mesh
Measure percentage；Pelletizing then, pellet roasting and metal recovery step are same as Example 1.Each metal recovery in the present embodiment
Rate record is shown in Table 3.
Embodiment 4
The present embodiment substantially with embodiment 3, the difference is that, smelting in clad 200 only is independently variable in embodiment 3
The particle diameter distribution of golden solid waste powder material B, and the selection of the present embodiment particle diameter distribution is same as Example 3, but in balling process,
The spherical radius D of internal layer pelletizing 1001And the thickness D of clad 2002Selection according to f and metallurgical solid waste powder material B partial size point
The relational expression of cloth situation:It is configured, α is that 90%, q takes 0.02 in the present embodiment, then f=4, i.e. internal layer pelletizing 100
Spherical radius D1For the thickness D of clad 20024 times.In the present embodiment, in balling process, control internal layer pelletizing 100
Spherical radius D1For 6mm or so, the thickness D of clad 200 is controlled2For 1.2mm or so, pelletizing, pellet roasting and metal then
Recycling step is same as Example 1.Each metal recovery rate record is shown in Table 3 in the present embodiment.
Comparative example 3
This comparative example substantially with embodiment 1, the difference is that, in the internal layer pelletizing 100 of the present embodiment and clad 200
In, both metallurgical solid waste powder A is identical as metallurgical solid waste powder material B particle diameter distribution partial size is less than the mass percent of 300 mesh
80%, pelletizing then, pellet roasting and metal recovery step are same as Example 1.Each metal recovery rate note in the present embodiment
Record is shown in Table 3.
Table 3 is embodiment 1, embodiment 2, embodiment 3, embodiment 4 and 3 internal layer pelletizing 100 of comparative example and clad 200
The record case of metal recovery rate in metallurgical solid waste size distribution and each embodiment.
The metallurgical solid waste size distribution of table 3 and metal recovery rate record sheet
Table 3 is analyzed, Examples 1 to 3 and comparative example 3 are compared into discovery, zinc, lead and iron in Examples 1 to 3
The rate of recovery be apparently higher than the rate of recovery of comparative example 3, and three embodiments of Examples 1 to 3 all have ideal metal
The rate of recovery；And the distinctive points of Examples 1 to 3 and comparative example 3 are that metallurgy used in the internal layer pelletizing 100 of Examples 1 to 3 is solid
The partial size of useless powder material B is distributed in 200 mesh~150 mesh more, i.e., the metallurgical solid waste powder that internal layer pelletizing 100 uses in Examples 1 to 3
B granularity is larger.Test is filled in the spy that applicant this has also been made other multiple groups, and final result also tends to above-mentioned multiple groups embodiment institute
It is showing as a result, by analysis, applicant thinks that its reason is:
(1) main function of the internal layer pelletizing 100 of pelletizing be realize internal layer pelletizing 100 in C element by Zn and Pb etc. a huge sum of money
Belong to element reduction into simple substance, if metallurgical solid waste powder A particle is too small in internal layer pelletizing 100, between metallurgical solid waste powder A
Gap is smaller, and the reduction of the heavy metal elements such as Zn and Pb can only be relied on and be restored between solid C in internal layer pelletizing 100, this
When reaction interface be mainly solid-solid phase reaction interface；And if the particle of metallurgical solid waste powder A is larger in internal layer pelletizing 100,
Gap between metallurgical solid waste powder A is larger, therefore C CO reducibility gas generated can enter in gap, in gap
The heavy metal elements such as Zn and Pb can be reduced into metallic zinc and metallic lead by middle CO, and reaction interface is mainly vapor solid at this time
Reaction interface；It is compared to solid-solid phase reaction interface, reaction rate can be improved in gas-solid phase reaction interface, and to react
More sufficiently；So the appropriate partial size for increasing metallurgical solid waste powder A, be conducive to improve metallic zinc and metallic lead in metallurgical solid waste
The rate of recovery.
(2) acting in the analysis to table 2 for the clad 200 of pelletizing has been described in, and main function is pair
Internal layer pelletizing 100 is conducted heat and is obstructed, and if the metallurgical solid waste powder material B grain diameter in clad 200 is larger, on the one hand
Gap between microcosmic metallurgical solid waste powder material B particle is larger more, fill a large amount of gas in the gap, and gas is led
Hot poor, if clad 200 containing excessive such gap, will lead to clad 200, heat-conducting effect subtracts on the whole
It is weak, and then internal layer pelletizing 100 is caused to be unable to reach higher temperature, influence the reduction of zinc and lead in internal layer pelletizing 100；In addition,
200 void of clad excessively influences whether the barrier property of clad 200；So appropriate reduce metallurgical solid waste powder material B particle
Partial size, can be improved the heating conduction of clad 200, and the barrier property of clad 200 can be enhanced, and then promote internal layer
The formation of reducing atmosphere in pelletizing 100.
In addition in table 3, embodiment 3 and embodiment 4 are compared, it is found that the rate of recovery of Zn and Pb in embodiment 4 is high
The rate of recovery in embodiment 3；And embodiment 3 and embodiment 4 are the difference is that embodiment 4 is adjusting clad 200
Meanwhile according to relational expression as described in example 4:The thickness of internal layer pelletizing 100 radius and clad 200 is had adjusted, this
And the rule that applicant summarizes in progress a large number of experiments process, applicant think by analysis: clad 200 is led
Hot property and isolation performance depend on two aspects, are on the one hand the thickness of clad 200, are on the other hand metallurgical solid waste powder material Bs
The size of grain diameter；And at the same time need to examine, influence of 100 radius of internal layer pelletizing for 200 Rational Thickness of clad,
In the case that whole pelletizing diameter is certain, in pelletizing the speed of the transmitting of heat and substance by 200 thickness of clad,
100 radius of internal layer pelletizing and the common influence of metallurgical solid waste powder material B grain diameter three, so needing in clad 200
A reasonable equilibrium relation is found between thickness, 100 radius of internal layer pelletizing and metallurgical solid waste powder material B grain diameter；Just think
If only simple as in Example 3 adjust metallurgical solid waste powder material B grain diameter, then be easy to cause clad 200 blocked up and
Too closely, it is unfavorable for the normal spilling of zinc fume and lead steam after restoring instead, and then influences effective recycling of zinc and lead.
The present invention is described in detail above in conjunction with specific exemplary embodiment.It is understood, however, that can not take off
It is carry out various modifications in the case where from the scope of the present invention being defined by the following claims and modification.Detailed description and drawings
Should be to be considered only as it is illustrative and not restrictive, if there is any such modifications and variations, then they all will
It falls into the scope of the present invention described herein.In addition, Development Status and meaning that background technique is intended in order to illustrate this technology,
It is not intended to limit the present invention or the application and application field of the invention.
Claims (10)
1. a kind of steel and iron industry solid waste valuable metal recovery method, which is characterized in that internal layer pelletizing is made in metallurgical solid waste powder A
(100), wherein ω in metallurgical solid waste powder AZnThe molar ratio of >=3%, C and Zn are k: l, and 1≤k≤5；Again by metallurgical solid waste powder
Material B is wrapped up on layer pelletizing (100) surface and is formed clad (200)；Pelletizing after cladding is placed in drying grate (400)-revolution
Kiln is preheated in (500), is roasted, so that the metallic zinc in pelletizing restores evaporation, by air extractor (501) to rotary kiln
(500) metallic zinc in is recycled.
2. a kind of steel and iron industry solid waste valuable metal recovery method according to claim 1, which is characterized in that specifically:
Step 1: ingredient:
According to Zn and C content in different types of metallurgical solid waste, metallurgical solid waste progress ingredient is obtained into metallurgical solid waste A, so that metallurgical
ω in solid waste AZnThe molar ratio of >=3%, C and Zn are k: l, wherein 1≤k≤5；Metallurgical solid waste progress ingredient is obtained into metallurgical solid waste again
ω in B, metallurgical solid waste BFe>=30%；
Step 2: broken:
Metallurgical solid waste A and metallurgy solid waste B are crushed respectively, metallurgy solid waste powder A and metallurgical solid waste powder material B are made respectively；
Step 3: pelletizing:
(1) metallurgy solid waste powder A, Xiang Yejin solid waste powder A water spray is added on disc balling machine (300), in disc balling machine
(300) it carries out pelletizing and internal layer pelletizing (100) is made；
(2) metallurgical solid waste powder material B is added in disc balling machine (300), water spray is so that metallurgical solid waste powder material B is adhered to metallurgy admittedly
The useless surface powder A forms clad (200)；
Step 4: pellet roasting
(1) cladding is placed on drying grate (400) and carries out drying and preheating；
(2) pelletizing after drying and preheating enters in rotary kiln (500) and is roasted；
Step 5: metal recovery
(1) be provided on rotary kiln (500) air extractor (501), after pelletizing is fired, zinc in internal layer pelletizing (100) with
The form of steam is volatilized, and is then trapped by air extractor (501), is realized effective recycling of zinc；
(2) it returns and is sintered after being crushed the pelletizing after roasting；Or magnetic separation is carried out after being crushed the pelletizing after roasting, after recycling roasting
Fe in pelletizing3O4Or metallic iron.
3. a kind of steel and iron industry solid waste valuable metal recovery method according to claim 2, which is characterized in that metallurgical solid waste
The molar ratio of C and Zn is k: l in A, and 1.5≤k≤3.
4. a kind of steel and iron industry solid waste valuable metal recovery method according to claim 2, which is characterized in that metallurgical solid waste
ω in Apb>=2%.
5. a kind of steel and iron industry solid waste valuable metal recovery method according to claim 2, which is characterized in that be crushed
Metallurgical solid waste A and metallurgy solid waste B are crushed by Cheng Zhong in sample pulverizer respectively, be made respectively metallurgy solid waste powder A with
Metallurgical solid waste powder material B, wherein the average particle size of metallurgical solid waste powder A is greater than the average particle size of metallurgical solid waste powder material B.
6. a kind of steel and iron industry solid waste valuable metal recovery method according to claim 2, which is characterized in that in pelletizing mistake
Cheng Zhong, the spherical radius of internal layer pelletizing (100) are D1, clad (200) with a thickness of D2, f=D1/D2, control 2≤f≤4.
7. a kind of steel and iron industry solid waste valuable metal recovery method according to claim 2, which is characterized in that pellet roasting
In the process, the maturing temperature in rotary kiln is 1050~1300 DEG C.
8. a kind of steel and iron industry solid waste valuable metal recovery method according to claim 2, which is characterized in that metal recovery
In the process, air extractor (501) is connected with cooling device, and cooling device carries out cooling recycling to zinc.
9. a kind of steel and iron industry solid waste valuable metal recovery method according to claim 5, which is characterized in that metallurgical solid waste
Powder A partial size is 60%~70% less than the mass percent of 150 mesh, quality hundred of the metallurgical solid waste powder material B partial size less than 300 mesh
Divide than being greater than 70%.
10. a kind of described in any item steel and iron industry solid waste valuable metal recovery methods, feature exist according to claim 1~9
In metallurgical solid waste A includes blast furnace ash and/or electric furnace ash；Metallurgical solid waste B includes converter ash and/or sintering ash.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110004291A (en) * | 2019-04-23 | 2019-07-12 | 中南大学 | A kind of method of Ferrous Metallurgy dust efficient process co-production direct-reduction iron powder |
| CN110420558A (en) * | 2019-08-27 | 2019-11-08 | 东方电气集团东方锅炉股份有限公司 | A kind of denitrating system for grate-kiln pelletizing equipment |
| CN114854985A (en) * | 2022-05-17 | 2022-08-05 | 宝武集团环境资源科技有限公司 | Method and system for cooperatively treating steel rolling oil sludge and iron-containing zinc dust sludge by rotary hearth furnace |
| CN115164202A (en) * | 2022-08-30 | 2022-10-11 | 中冶长天国际工程有限责任公司 | Multiphase coupling organic/heavy solid-containing waste cooperative treatment process, system and control method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101613800A (en) * | 2009-07-17 | 2009-12-30 | 重庆瑞帆再生资源开发有限公司 | Adopt metallurgical composite pellet, preparation method and application that twice the balling-up mode is made |
| CN101717854A (en) * | 2009-12-25 | 2010-06-02 | 重庆瑞帆再生资源开发有限公司 | Method for producing metallized pellet by using metallurgical roasting furnace |
| CN103451421A (en) * | 2013-09-06 | 2013-12-18 | 鞍钢股份有限公司 | Preparation method of blast furnace sludge pre-reduced pellet |
| CN104726699A (en) * | 2015-03-25 | 2015-06-24 | 甘肃酒钢集团宏兴钢铁股份有限公司 | High-strength composite metallized pellets produced by using iron-containing metallurgical dust and production process thereof |
| WO2016170467A1 (en) * | 2015-04-24 | 2016-10-27 | Sabic Global Technologies B.V. | Composite iron pellets and methods of making same |
-
2018
- 2018-12-28 CN CN201811629371.0A patent/CN109468467B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101613800A (en) * | 2009-07-17 | 2009-12-30 | 重庆瑞帆再生资源开发有限公司 | Adopt metallurgical composite pellet, preparation method and application that twice the balling-up mode is made |
| CN101717854A (en) * | 2009-12-25 | 2010-06-02 | 重庆瑞帆再生资源开发有限公司 | Method for producing metallized pellet by using metallurgical roasting furnace |
| CN103451421A (en) * | 2013-09-06 | 2013-12-18 | 鞍钢股份有限公司 | Preparation method of blast furnace sludge pre-reduced pellet |
| CN104726699A (en) * | 2015-03-25 | 2015-06-24 | 甘肃酒钢集团宏兴钢铁股份有限公司 | High-strength composite metallized pellets produced by using iron-containing metallurgical dust and production process thereof |
| WO2016170467A1 (en) * | 2015-04-24 | 2016-10-27 | Sabic Global Technologies B.V. | Composite iron pellets and methods of making same |
Non-Patent Citations (1)
| Title |
|---|
| 张寿荣等: "《高炉高效冶炼技术》", 31 May 2015, 冶金工业出版社 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110004291A (en) * | 2019-04-23 | 2019-07-12 | 中南大学 | A kind of method of Ferrous Metallurgy dust efficient process co-production direct-reduction iron powder |
| CN110420558A (en) * | 2019-08-27 | 2019-11-08 | 东方电气集团东方锅炉股份有限公司 | A kind of denitrating system for grate-kiln pelletizing equipment |
| CN114854985A (en) * | 2022-05-17 | 2022-08-05 | 宝武集团环境资源科技有限公司 | Method and system for cooperatively treating steel rolling oil sludge and iron-containing zinc dust sludge by rotary hearth furnace |
| CN115164202A (en) * | 2022-08-30 | 2022-10-11 | 中冶长天国际工程有限责任公司 | Multiphase coupling organic/heavy solid-containing waste cooperative treatment process, system and control method |
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