CN101343692A

CN101343692A - Carbon based reductive

Info

Publication number: CN101343692A
Application number: CNA200810011557XA
Authority: CN
Inventors: 李裕华; 高翔; 石秀华
Original assignee: FUXIN HUAWEI METALLURGICAL NEW MATERIALS Co Ltd
Current assignee: FUXIN HUAWEI METALLURGICAL NEW MATERIALS Co Ltd
Priority date: 2008-05-21
Filing date: 2008-05-21
Publication date: 2009-01-14

Abstract

The invention relates to a carbon-based reducing agent used for producing the direct reduced iron, which belongs to the ferrous metallurgy technique. The reducing agent is composed of the following components, by weight: 600 parts to 650 parts of anthracite coal, 150 parts to 200 parts of quicklime, 100 parts of limestone, 100 parts of dolomite, fixed carbon of anthracite coal is equal to or more than 70 percent, in which the sulfur content is less than 0.10 percent; calcium oxide of quicklime is equal to or more than 90 percent, in which the sulfur content is less than 0.10 percent; calcium carbonate of limestone is equal to or more than 50 percent, in which the sulfur content is less than 0.10 percent; and magnesium carbonate of dolomite is equal to or more than 60 percent, in which the sulfur content is less than 0.10 percent. The invention has the advantages that after the carbon-based reducing agent is used, the reduction time can be shortened by 25 percent to 35 percent, the production efficiency can be increased by about more than 30 percent, the adding amount of the carbon-based reducing agent can be controlled to 40 percent to 50 percent according to the weight of the iron ore powder or iron ore, the usage of the reducing agent can be saved by more than 50 percent, and the production cost is reduced.

Description

Carbon based reductive

Technical field

The invention belongs to the ferrous metallurgy technology, particularly a kind ofly produce the carbon based reductive that direct-reduced iron is used.

Background technology

In recent years, because the shortage of energy conservation and environment protection and coke resource and national macroscopic view restriction to the iron and steel production capacity, National Development and Reform Committee bans and limits small furnace production; Because the social shortage of steel scrap resource and in recent years because steel products are advanced towards miniaturization and, function, compoundization direction develops, non-metallic material and non-ferrous metal usage ratio increase in the steel, cause waste steel quality constantly to descend again.Steel scrap is as the electric steel raw material, because its source is different, chemical component fluctuation is very big, and is difficult to grasp, control, and this has brought great difficulty for the Electric furnace steel making operation, makes Electric furnace steel making and casting industry production high-quality steel more and more rely on direct-reduced iron.State Economic and Trade Commission has classified direct-reduced iron (sponge iron) technology as one of Eleventh Five-Year Plan three big scientific and technological development projects; National Development and Reform Committee classifies the direct-reduced iron project of yearly capacity more than 150,000 tons as the project of encourage growth and supports in the up-to-date industry catalogue of 11th Five-Year, thereby impels the direct-reduced iron project comparatively fast to be developed in the recent period.

The canned method of tunnel furnace is produced direct-reduced iron and is had that technical maturity is reliable, less investment, instant effect, cost is low, product grade is high and stable, simple to operate, stable equipment operation, energy consumption is low, not harsh to the requirement of raw material, scale is flexible, the high advantages such as (generally more than 30%) of utilization coefficient, belongs to mature and reliable at home and uses maximum technology.So far since scope of the enterprise little, distribute to disperse, though more exploration is arranged on production method, to the research of aspects such as direct reduction mechanism, production technique, production unit seldom.

The canned method of tunnel furnace is produced direct-reduced iron and is adopted carbon based reductive.The distribution of domestic carbon based reductive mainly contains: the unslaked lime of hard coal with addition of 30%; The coke powder is with addition of 20～30% unslaked limes; Bituminous coal or semibituminous coal are several with addition of 20～30% unslaked limes.Obviously, mainly be to utilize [C] in coal or the coke as reductive agent, utilize CaO as sweetening agent or sulphur-fixing agent.The problem that exists is a long reaction time, and production efficiency is low, and degree of metalization reached reaction times required more than 90% greater than 40 hours.

Summary of the invention

The objective of the invention is to overcome above-mentioned technical deficiency, a kind of carbon based reductive that reaction times is short, production efficiency is high that direct-reduced iron is used of producing is provided.

The technical scheme that technical solution problem of the present invention adopts is: a kind of carbon based reductive is grouped into by following one-tenth, by weight: 600～650 parts in hard coal, 150～200 parts of unslaked limes, 100 parts in Wingdale, 100 parts of rhombspars; Wherein, anthracitic fixed carbon 〉=70%, sulphur content are less than 0.10%; The calcium oxide of unslaked lime 〉=90%, sulphur content are less than 0.10%; The lime carbonate of Wingdale 〉=50%, sulphur content are less than 0.10%; The magnesiumcarbonate of rhombspar 〉=60%, sulphur content are less than 0.10%.

Hard coal (English name anthracite) is commonly called as anthracite or anthracite.It is the coal of degree of coalification maximum.Hard coal fixed carbon content height, volatile matter is low, and density is big, and hardness is big, and the burning-point height is not smoldered during burning, noncoking.General carbon content is more than 90%, and volatile matter is below 10%.No thickness of colloidal matter layer.The about 5000-5500 kilocalorie of calorific value/kilogram.It is industries such as chemical fertilizer (nitrogenous fertilizer, synthetic ammonia), pottery, casting forging that hard coal lump coal is mainly used; Anthracite fine coal is mainly used in metallurgy industry and is used for blast furnace blowing.

Unslaked lime: major ingredient calcium oxide, molecular formula: CaO.

Wingdale: major ingredient lime carbonate, molecular formula CaCO ₃, molecular weight 100.09. character: white powder.Odorless, tasteless.Reveal and put no change in the air, proportion 2.710.1339 ℃ of fusing points.Water-solublely hardly in the water that contains ammonium salt or ferric oxide, dissolve, be insoluble to alcohol.Meet dilute acetic acid, dilute hydrochloric acid, rare nitric acid generation intumescence, and dissolving.Thermal degradation is calcium oxide and carbonic acid gas.Purposes: press the difference of smashing fineness, industrially be divided into four kinds of different sizes: solo flight, round trip flight, three fly, four fly, and is respectively applied for each industrial sector.

Rhombspar: major ingredient lime carbonate and magnesiumcarbonate, molecular formula is: CaCO ₃, MgCO ₃

The invention has the beneficial effects as follows: use carbon based reductive of the present invention, be applied to the canned method of tunnel furnace and produce direct-reduced iron, can shorten the recovery time 25～35%, it is about more than 30% to enhance productivity.Produce 1.5 ten thousand tons tunnel furnace per year and use new reductive agent, output can reach more than 20,000 tons.The reductive agent add-on of the hard coal of common use and the preparation of 30% unslaked lime approximates and is reduced powdered iron ore or lump ore weight; Use carbon based reductive add-on of the present invention to get final product, can save the reductive agent consumption more than 50%, reduce production costs according to 40～50% controls of powdered iron ore or iron ore weight.

Embodiment

Embodiment one: a kind ofly produce the carbon based reductive that direct-reduced iron is used, be grouped into by following one-tenth, by weight: fixed carbon 〉=70%, sulphur content less than 0.10% hard coal 600Kg, calcium oxide 〉=90%, sulphur content less than 0.10% unslaked lime 150Kg, calcium oxide 〉=50%, sulphur content is less than 0.10% Wingdale 100Kg, and magnesiumcarbonate 〉=60%, sulphur content are less than 0.10% rhombspar 100Kg.

The preparation method of carbon based reductive, it may further comprise the steps: a, at first get fixed carbon 〉=70% sulphur content less than 0.10% hard coal 600Kg, calcium oxide 〉=90%, sulphur content less than 0.10% unslaked lime 150Kg, calcium oxide 〉=50%, sulphur content are less than 0.10% Wingdale 100Kg, magnesiumcarbonate 〉=60%, sulphur content carry out just broken respectively less than 0.10% rhombspar 100Kg; B, will just break the material separated pulverizing to granularity be≤2.0mm; C, with stirrer with grinding particle size be≤mixing of materials of 2.0mm evenly gets final product.

The using method of this reductive agent is that 15Kg powdered iron ore or lump ore stone are joined in the retort, and then adding reductive agent 6.0Kg, retort is placed on delivers to tunnel furnace heating on the chassis, 850 ℃～1180 ℃ of control reaction temperature, its result: the recovery time is 26 hours, degree of metalization 96%, desulfurization degree 54%.

Embodiment two: the carbon back reducing material that a kind of direct production reduced iron is used, be grouped into by following one-tenth, by weight: fixed carbon 〉=70% sulphur content less than 0.10% hard coal 650Kg, calcium oxide 〉=90% sulphur content less than 0.10% unslaked lime 200Kg, calcium oxide 〉=50% sulphur content is less than 0.10% Wingdale 100Kg, and magnesiumcarbonate 〉=60% sulphur content is less than 0.10% rhombspar 100Kg.

The preparation method of carbon based reductive: at first get fixed carbon 〉=70% sulphur content less than 0.10% hard coal 650Kg, calcium oxide 〉=90% sulphur content less than 0.10% unslaked lime 200Kg, calcium oxide 〉=50% sulphur content less than 0.10% Wingdale 100Kg, magnesiumcarbonate 〉=60% sulphur content is carried out just broken respectively less than 0.10% rhombspar 100Kg; B, will just break the material separated pulverizing to granularity be≤2.0mm; C, with stirrer with grinding particle size be≤mixing of materials of 2.0mm evenly gets final product.

The using method of this reductive agent is that 15Kg powdered iron ore or lump ore stone are joined in the retort, and then adding reductive agent 6.0Kg, retort is placed on delivers to tunnel furnace heating on the chassis, 850 ℃～1180 ℃ of control reaction temperature, its result: the recovery time is 30 hours, degree of metalization 95%, desulfurization degree 47%.

Claims

1, a kind of carbon based reductive is grouped into by following one-tenth, by weight: 600～650 parts in hard coal, 150～200 parts of unslaked limes, 100 parts in Wingdale, 100 parts of rhombspars.

2, carbon based reductive according to claim 1 is characterized in that anthracitic fixed carbon 〉=70%, sulphur content are less than 0.10%; The calcium oxide of unslaked lime 〉=90%, sulphur content are less than 0.10%; The lime carbonate of Wingdale 〉=50%, sulphur content are less than 0.10%; The magnesiumcarbonate of rhombspar 〉=60%, sulphur content are less than 0.10%.