CN102199681B - Method for separating and enriching iron and rare earth in rare earth crude ore containing iron - Google Patents

Abstract

The invention discloses a method for separating and enriching iron and rare earth in rare earth crude ore containing iron, which belongs to the field of ironmaking, relates to a method for separating and enriching rare earth and iron in the rare earth crude ore containing iron and is used for the comprehensive utilization of the rare earth crude ore containing iron. The method is characterized in that: the rare earth crude ore containing iron, a carbon-containing reducer, a bonding agent and an additive are used as raw material; and the process comprises the steps of ore grinding, material preparation, uniform mixing, agglomeration, reducing and melt extraction, crushing and magnetic separation; and thus, beaded iron and rare earth enriched slag can be prepared. The produced beaded iron can be used as a raw material for steelmaking in an electric furnace or a converter; the rare earth enriched slag can be used for producing rare earth silicoferrite or dressed to produce rare earth concentrate; and thus, the iron resources and rare earth resources can be fully utilized, and the rare earth crude ore containing iron can be comprehensively used. The method can satisfy the needs of steel industry and rare earth industry and can create great social and economic benefit.

Description

A kind of method for iron content rare-earth original ore iron and Rare Earth Separation enrichment

Technical field

The invention belongs to the ironmaking field, relate to the method for rotary hearth furnace comprehensive utilization iron content rare-earth original ore, be used for the development and use of iron content rare-earth original ore.

Background technology

Rare earth refers to lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc) and the 17 kinds of elements of yttrium (Y) in the periodic table of chemical element.Rare earth mineral deposit generally all contains multiple useful component, and its middle-weight rare earths, niobium, iron etc. are main comprehensive recycle object.Many large-scale niobium deposits, ferruginous deposits, phosphorus deposit and nepheline mineral deposit also are rare earth mineral deposits simultaneously in the world.

Baiyunebo iron mine is exactly unique mineral deposit of typical rare earth, niobium and iron symbiosis.Baiyunebo iron mine has advantageous resources advantage, has now found that 175 kinds of mineral, and 71 kinds of elements have the unit that maybe may have comprehensive utilization value and have 26 kinds.Rare earth resources ranks first in the world, and the niobium resource occupies the second place of the world.Now, 1,200 ten thousand ton/years of main Dong Kuang design production capacities, content of rare earth is close, is about 6.0%.1.7 hundred million tons of present main ore reserves, 0.6 hundred million tons of eastern ore reserves, calculating main Dong Kuang with this will be exhausted about 20 years, therefore extremely urgent to the comprehensive utilization of baiyuneboite.

Be generally and save the cost of smelting, must carry out the ore dressing processing to the iron content rare-earth original ore and be used further to smelt.But for the iron content rare-earth original ore, rare-earth mineral and other mineral are closely inlayed, be difficult to enrichment with common method, although can pass through weak magnetic-strong magnetic-floatation process, obtain iron ore concentrate and rare earth ore concentrate, but iron recovery is 70%, and rare earth yield is 10% only, has caused the great wasting of resources.Therefore, be necessary to research and develop a kind of new technical process, to realize its comprehensive utilization.

The pyrogenic process separating technology mainly is based on the principle of selective reduction, wherein ferriferous oxide more easily reduces, and the difficult reduction of rare earth oxide becomes metallic iron with coke, reducing gas or coal dust with reduction of ferrous oxide, divides with crushing-magnetic selection by high temperature melting and realizes rare earth, iron separation and concentration.

Summary of the invention

The method that the object of the present invention is to provide a kind of technical iron content rare-earth original ore feasible, reasonable in economy to fully utilize is developed the flow process of low-grade iron content rare-earth original ore comprehensive utilization, thereby is taken full advantage of China's iron resources and rare earth resources.The invention is characterized in take rotary hearth furnace as equipment, utilize the rare earth grade greater than 5.4%, the iron grade is raw material greater than 25% iron content rare-earth original ore and carbon containing reducer, binding agent, additive, making carbon content through ore grinding, batching, mixing, agglomeration, the molten operation of grading of reduction is that 2.0～4.0% pearl iron and rare earth grade are higher than 12% the rich slag of rare earth.

Ultimate principle is:

Iron content rare-earth original ore breeze and carbon containing reducer are made carbonaceous pelletizing, and when temperature in the stove was 1350～1450 ℃, the oxide compound of iron with preferential gradual deoxidizing out in the breeze.When the metallic iron carburizing amount that restores reaches certain value, when iron begins to melt, part Nb will be arranged ₂O ₅Reduction and enter pearl iron, all the other RE ₂O ₃With MgO, CaO, Al ₂O ₃, SiO ₂Stay in the slag.Because the difference of slag iron aspect density, surface tension, viscosity realizes that slag iron separates, and gives birth to the rich slag of balling iron and rare earth.The principal reaction that carbonaceous pelletizing occurs in the molten minute process of reduction is as follows:

(1) direct reduction reactor

3Fe ₂O ₃+C＝2Fe ₃O ₄+CO

${\mathrm{\Δ}}_r{G}_1^{\mathrm{\θ}}=120000-218.46\mathrm{TJ}/\mathrm{mol},$ T _b＝276.15℃

Fe ₃O ₄+C＝3FeO+CO

${\mathrm{\Δ}}_r{G}_2^{\mathrm{\θ}}=207510-217.62\mathrm{TJ}/\mathrm{mol},$ T _b＝680.39℃

FeO+C＝Fe+CO

${\mathrm{\Δ}}_r{G}_3^{\mathrm{\θ}}=158970-160.25\mathrm{TJ}/\mathrm{mol},$ T _b＝718.86℃

1/4Fe ₃O ₄+C＝3/4Fe+CO

${\mathrm{\Δ}}_r{G}_4^{\mathrm{\θ}}=171100-174.5\mathrm{TJ}/\mathrm{mol},$ T _b＝707.37℃

Nb ₂O _5(s)+7C _(s)＝2NbC _(s)+5CO _(g)

${\mathrm{\Δ}}_r{G}_5^{\mathrm{\θ}}=1042485.44-843.70\mathrm{TJ}/\mathrm{mol},$ T _b＝962.46℃

(2) indirect reduction reaction

3Fe ₂O ₃+CO＝2Fe ₃O ₄+CO

${\mathrm{\Δ}}_r{G}_6^{\mathrm{\θ}}=-52131-41.0\mathrm{TJ}/\mathrm{mol},$ Any temperature all can occur on this reaction theory

Fe ₃O ₄+CO＝3FeO+CO ₂

${\mathrm{\Δ}}_r{G}_7^{\mathrm{\θ}}=35380-40.16\mathrm{TJ}/\mathrm{mol},$ T _b＝607.83℃

FeO+CO＝Fe+CO ₂

${\mathrm{\Δ}}_r{G}_8^{\mathrm{\θ}}=-22800+24.26\mathrm{TJ}/\mathrm{mol},$ T _f＝566.67℃

(3) Carbon gasification reaction

C+CO ₂＝2CO

${\mathrm{\Δ}}_r{G}_9^{\mathrm{\θ}}=166550-171\mathrm{TJ}/\mathrm{mol},$ T _b＝700.83℃

(4) carburization reaction

Indirect carburizing: 2CO=[C]+CO ₂

${\mathrm{\Δ}}_r{G}_{10}^{\mathrm{\θ}}=-143960+128.7\mathrm{TJ}/\mathrm{mol},$ T _f＝845.4℃

Direct carburizing: C=[C]

${\mathrm{\Δ}}_r{G}_{11}^{\mathrm{\θ}}=22590-42.26\mathrm{TJ}/\mathrm{mol},$ T _b＝261.4℃

T _bRepresent that the reaction of above-mentioned reaction under standard state begins temperature, T _fBe illustrated in the reaction terminating temperature under the standard state.Can be found out that by above-mentioned reaction the preferential gradual deoxidizing of the oxide compound of iron out presents molten state through over carburizing, and then the shape balling iron, the oxide compound of niobium is in the situation that has molten iron to exist, and part is reduced, and enters iron phase with the form of NbC.In the present invention, iron, slag do not reach fully fusing, and be mobile relatively poor, and slag and iron duration of contact is short, area is little, so the reduction kinetics condition of rare earth is very poor, the RE that fails to reduce ₂O ₃And CaF ₂, CaO, SiO ₂, MgO, Al ₂O ₃Form the slag phase, thereby realize separating of iron and rare earth.

According to above-mentioned principle, this invention is take rotary hearth furnace as equipment, and concrete production process is:

Material condition is:

The all iron content of iron content rare-earth original ore between 25～40%, RE ₂O ₃Content is not less than 5.5%, and the granularity of breeze reaches-200 orders more than 90%.

Fixed carbon in the coal dust is more than 80%, and ash content is below 10%, and granularity reaches-80 orders more than 90%.

Binding agent is profit soil, molasses, bean powder or dextrin.

Additive is CaO, MgO, TiO ₂

Technical process is:

(1) with iron content rare-earth original ore breeze, carbon containing reducer (coal dust, coke powder etc.), binding agent and additive (CaO, MgO, TiO ₂) use the mixer mixing, wherein the amount of allocating into of reductive agent be iron content rare-earth original ore amount 11～18%, the amount of allocating into of binding agent be iron content rare-earth original ore amount 2～3%, the amount of allocating into of additive is 0～5% of iron content rare-earth original ore amount;

(2) total moisture of compound is 7～10%, makes pelletizing with pelletizer behind the mixer mixing, dry for standby;

(3) then the thick carbon dust of place mat 3～5mm on the refractory materials of rotary furnace bottom is layered on dried pelletizing on the carbon dust uniformly, is generally 1～2 layer.Temperature in the rotary hearth furnace is 1350～1450 ℃, and the molten minute time of reduction is 9～20 minutes.Pelletizing is discharged by overcooling, fragmentation, magnetic separation, finally obtains carbon content and be 2.0～4.0% pearl iron and rare earth grade and be two kinds of products of the rich slag of rare earth of 12～20%.

Because the sulphur that iron content rare-earth original ore, carbon containing reducer are brought in the pearl iron in this technique is more, and the reaction system desulfurization condition is poor, for guaranteeing that sulphur content is relatively qualified in the pearl iron, must reinforcing desulfuration.As breeze carried out desulfurization flotation, oxidizing roasting desulfurization, select the low reductive agent of sulphur content, with addition of a certain amount of lime, take secondary desulfurization etc.

CaF in the rich slag of rare earth ₂Content is higher, can reach more than 30%, and the fusing point of slag is lower, rational flowability can be arranged and avoid molten to the erosion of refractory materials for guaranteeing slag, can allocate MgO, CaO, TiO into ₂Improve the temperature of fusion of slag.

After making the rich slag of pearl iron and rare earth, pearl iron can replace steel scrap or add converter or electric furnace as the steel-making refrigerant, and RE in the rich slag of rare earth ₂O ₃Content can reach 12～20%, owing to relatively relax through high-temperature fusion and the type of cooling, contains RE ₂O ₃The crystallizable mineral granularity larger, completely enough requirements of next step ore dressing.

Advantage of the present invention is: (1) is separated the valuable elements such as rare earth in the iron content rare-earth original ore, iron fully, and then can be the iron content rare-earth original ore and realize that comprehensive utilization lays a solid foundation.

(2) take coal as main reductive agent, meet the energy structure of China.

(3) carry out rare earth, iron separation take rotary hearth furnace as major equipment, advanced technology, produce flexibly, cost is low, strong adaptability, environmental friendliness, be easy to promote, be particularly suitable for building near the mine, can be rare earth chemical enterprise and a large amount of transportation cost of iron and steel enterprise's saving.

(4) rotary hearth furnace rare earth, iron separating effect are better, can obtain the rich slag of pearl iron and rare earth, and wherein the pearl weight of iron is high, and it is of high grade but also grain size number enrichment phase is larger that the rich slag of rare earth not only contains rare earth, can satisfy the requirement of next step processing.The recovery rate of iron and rare earth is higher, and wherein the recovery rate of iron can reach 97%, and the recovery rate of rare earth is near 100%.

Description of drawings

Fig. 1 is the flow process of technique of the present invention.

Embodiment

Embodiment 1

With iron content 30.20%, contain RE ₂O ₃Be 5.50% raw ore breeze and the weight coal dust that is iron content rare-earth original ore weight 13% and weight be iron content rare-earth original ore and coal dust summation 2% binding agent through Belt Conveying to the mixer mixing, and regulate mixing material moisture to 7%.The mixing material that mixes is made carbonaceous pelletizing through Belt Conveying to the pair roller ball press, and pressure is 15MPa, and pelletizing is of a size of 40 * 30 * 20mm pillow ellipsoid.The thick carbon dust of place mat 3～5mm is layered on dried pelletizing on the carbon dust uniformly on the refractory materials of rotary furnace bottom, is generally 1～2 layer.Temperature in the rotary hearth furnace is 1400～1450 ℃, and the residence time of pelletizing in rotary hearth furnace is 9～20 minutes, then discharged at discharge port by discharging machine.The product of discharging is sent into the magnetic separator magnetic separation after cooling, coarse breaking, the ferromagnetism thing is pearl iron after the choosing, and non magnetic and weak Magnetic Materials is the rich slag of rare earth.

The chemical ingredients % of table 1 the first iron content rare-earth original ore

Embodiment 2

To contain RE ₂O ₃Be 6.56% iron content rare-earth original ore breeze, weight be 2% binding agent of the additive MgO of coal dust, iron content rare-earth original ore weight 2% of iron content rare-earth original ore weight 12% and iron content rare-earth original ore and coal dust weight summation through Belt Conveying to the mixer mixing, and regulate mixing material moisture to 8%.The mixing material that mixes is made carbonaceous pelletizing through Belt Conveying to the pair roller ball press, and pressure is 15MPa, and pelletizing is of a size of 40 * 30 * 20mm pillow ellipsoid.The thick carbon dust of place mat 3～5mm is layered on dried pelletizing on the carbon dust uniformly on the refractory materials of rotary furnace bottom, is generally 1～2 layer.Temperature in the rotary hearth furnace is 1400～1450 ℃, and the residence time of pelletizing in rotary hearth furnace is 9～20 minutes, then discharged at discharge port by discharging machine.The product of discharging is sent into the magnetic separator magnetic separation after cooling, coarse breaking, the ferromagnetism thing is pearl iron after the choosing, and non magnetic and weak Magnetic Materials is the rich slag of rare earth.

The chemical ingredients % of table 4 the second iron content rare-earth original ore

The chemical ingredients % of table 5 pearl iron

The main component % of the rich slag of table 6 rare earth

Embodiment 3

To contain RE ₂O ₃Be 5.95% iron content rare-earth original ore breeze, weight be 2% binding agent of the additive MgO of coal dust, iron content rare-earth original ore weight 5% of iron content rare-earth original ore weight 12% and iron content rare-earth original ore and coal dust weight summation through Belt Conveying to the mixer mixing, and regulate mixing material moisture to 9%.The mixing material that mixes is made carbonaceous pelletizing through Belt Conveying to the pair roller ball press, and pressure is 15MPa, and pelletizing is of a size of 40 * 30 * 20mm pillow ellipsoid.The thick carbon dust of place mat 3～5mm is layered on dried pelletizing on the carbon dust uniformly on the refractory materials of rotary furnace bottom, is generally 1～2 layer.Temperature in the rotary hearth furnace is 1400～1450 ℃, and the residence time of pelletizing in rotary hearth furnace is 9～20 minutes, then discharged at discharge port by discharging machine.The product of discharging is sent into the magnetic separator magnetic separation after cooling, coarse breaking, the ferromagnetism thing is pearl iron after the choosing, and non magnetic and weak Magnetic Materials is the rich slag of rare earth.

The chemical ingredients % of the third iron content rare-earth original ore of table 7

The chemical ingredients % of table 8 pearl iron

The main component % of the rich slag of table 9 rare earth

Claims (1)

1. method that is used for iron content rare-earth original ore iron and Rare Earth Separation enrichment, it is characterized in that utilizing iron content rare-earth original ore, carbon containing reducer, binding agent and additive to be raw material, process comprises ore grinding, batching, mixing, agglomeration, molten minute of reduction, broken, magnetic separation operation, can make two kinds of products of the rich slag of pearl iron and rare earth;

Main production flow process and parameter are:

(1) with iron content rare-earth original ore breeze, carbon containing reducer, binding agent and additive mixer mixing, wherein the amount of allocating into of reductive agent be iron content rare-earth original ore amount 11～18%, the amount of allocating into of binding agent be iron content rare-earth original ore amount 2～3%, the amount of allocating into of additive is 0～5% of iron content rare-earth original ore amount; Described carbon containing reducer is coal dust or coke powder, fixed carbon content more than 80%, ash content below 10%, granularity more than 90% less than 80 orders; Binding agent is wilkinite, molasses, bean powder or dextrin; Additive is CaO, MgO, TiO ₂

(2) total moisture of compound is 7～10%, makes pelletizing with pelletizer behind the mixer mixing, dry for standby;

(3) the thick carbon dust of place mat 3～5mm on the refractory materials of rotary furnace bottom, then be layered on uniformly dried pelletizing on the carbon dust, be generally 1～2 layer, temperature in the rotary hearth furnace is 1350～1450 ℃, the molten minute time of reduction is 9～20 minutes, pelletizing is discharged by overcooling, fragmentation, magnetic separation, can obtain carbon content and is 2.0～4.0% pearl iron and rare earth grade and be higher than two kinds of products of the rich slag of rare earth of 12%;

The RE of described iron content rare-earth original ore ₂O ₃Content is greater than 5.4%, and the iron grade is greater than 25%, granularity through ore grinding more than 90% less than 200 orders.

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