CN101229526A - Method of using blast furnace scrap iron in slag to prepare puron materiel - Google Patents

Abstract

The invention discloses a method for preparing highly pure metallic iron material using blast furnace metal and slag. By adopting magnetic-gravitational associated closed-circuit separation of a one-time magnetic separation, a one-time table concentration and returned middling for reselecting, the blast furnace iron slag with a small particle size are put into a ball mill for milling. After sieved, the magnetic separation and the table concentration are carried out for the milled material for obtaining the finished products. The invention has the advantages of short technical process, low energy consumption and no pollution, as well as capability of preparing iron material with high purity.

Description

A kind of method with blast furnace scrap iron in slag to prepare puron materiel

Technical field

The invention belongs to solid waste comprehensive utilization of resources technical field, relate to the recycling of the blast furnace slag that ironmaking produces, particularly a kind of method of from blast furnace slag iron, extracting iron.

Background technology

Steel plant produce a large amount of blast furnace slags inevitably in ironmaking.The ordinary blast slag generally contains the iron resource of 1-3% according to the difference of slag.In short supply day by day along with domestic and international iron ore resource improves the utilization rate of iron resource and added value of product and becomes the major issue that steel plant in recent years pay close attention to, and nearly all steel plant have all carried out extensive work to the recycling of iron content blast furnace slag.

The blast furnace slag recovery processing technique that generally adopts has two kinds at present: shrend and slow cooling (also being hot application) technology.The blast-furnace cinder that adopts water quenching technology to handle, slag, iron natural separation in the shrend process, iron recovery is higher in the blast furnace slag.The slag iron clamp is assorted in employing slow cooling (also being hot application) the PROCESS FOR TREATMENT gained blast furnace slag, after PROCESS FOR TREATMENT such as fragmentation, magnetic separation, the slag iron of granularity＞5mm has obtained good recycling, but the slag iron that granularity≤5mm is following is because its metal Ferrum content (MFe＜30%) is low, and the iron in this part product is to be embedded in the slag with graininess, slag, iron separation difficulty, iron are difficult to reclaim.The steel mill that has does not simply reclaim, and does discarded the processing; What have reclaims, and gained slag iron MFe is about 45-55%, mainly returns the sintering deposit batching and uses, and its price and iron ore concentrate are suitable.

Climb steel and produce 3500000 tons of high-titanium blast furnace slags per year because the steel climbing high slag slag is short, in the slag contained metallic iron many with tiny iron shot shape embedding cloth in slag, cause slag in the blast furnace slag, iron separation difficulty, iron content is 3-5% in the slag.Wherein reclaim the slag iron of gained granularity≤5mm, its MFe is about 50%, and TFe is 70-85%, and yield accounts for 55% of slag iron total amount, mainly at present returns ironmaking again as blast furnace raw material, and added value of product is not high, causes the significant wastage of resource.

From existing document, about the report of blast furnace scrap iron in slag to prepare puron materiel with study actually rare.Report in the patent of invention " slag iron ball and slag iron powder reclaim technology in the steel-iron slag " (patent No. is ZL200410054128.2): to the steel-iron slag magnetic concentration working below the 5mm, isolate the following slag iron powder semi-finished product of 5mm, wash again-magnetic concentration working, the slag iron powder MFe that obtains is between 45%-55%, TFe is 70-85%, mainly returns the sintering deposit batching and uses.

Report in the patent of invention " a kind of method of producing iron powder " (the ZL patent No. 96102647.2): utilize converter stove dirt to be raw material, through mill choosing, oven dry, smart reduction, broken, screening, close batch packed products again, it is two sections ball millings, shaking table that its mill selects flow process, promptly through one section ball milling, one section shaking table, enter two sections ball millings, two sections shaking tables again, and control to enter and grind mine-supplying quantity and the concentration of selecting flow process, reach the standard and the performance requirement of country-level welding rod usefulness iron powder with the iron powder of converter stove dirt production.

The former recycles the steel-iron slag below the 5mm, but gained slag iron iron grade is low, and MFe content only is 45-55%, and recovery utilization rate and added value are not high; The latter utilizes converter stove dirt to produce iron powder for raw material, and particle diameter own is thin, and has shortcomings such as technological process is long, energy consumption is high, production cost height.

Look into and newly show at present not with MFe content to be the precedent of about 50% blast furnace scrap iron in slag to prepare puron materiel method.

Summary of the invention

At present the above-mentioned problems in the prior art, it is raw material with blast furnace slag iron that the object of the invention is to provide a kind of, produces the method for high-load (90%) metallic iron MFe.

Technical scheme of the present invention is, described a kind of method with blast furnace scrap iron in slag to prepare puron materiel adopts a magnetic separation, table concentration, a chats to return the magnetic of choosing again-heavily unite closed circuit flow process, step realization in the following order:

1. the blast furnace slag iron with small particle diameter enters the ball mill ball milling, goes out grind materials and enters the screening flow process;

2. will sieve thick material after the flow processing and enter the magnetic separation of magnetic separation operation and obtain abrasive grit, intermediate material is that chats returns ball milling operation ball milling again, and thin material enters the table concentration operation;

3. the oven dry of the micro-size fraction iron powder behind the table concentration is promptly obtained finished product.

Adopt this method MFe content in the former slag iron can be brought up to more than 90% from about 50%, obtain granularity respectively and be the high pure metal abrasive grit of 1.18mm-5mm and granularity less than the titanium white of 0.425mm with two kinds of high pure metal iron of reduced iron powder material, and the rate of recovery that makes iron resource in the slag is greater than 90%, get to the limit and recycle, improve solid waste resource product added value simultaneously, open up the new purposes of slag iron product.

Compare with the existing technology that reclaims, adopt the inventive method effectively the metal in the dreg iron content to be brought up to more than 90% from 50%, residual iron content is reduced to below 6% in the tailings, makes that the iron resource number of dropouts drops to minimum level in the blast furnace slag, and the present invention has improved blast furnace slag iron recovery utilization rate greatly.

Do not have operations such as smart reduction because of the present invention, have advantages such as low, the no toxic gas generation of energy consumption.Technological process is simple, feasible, and small investment, process do not produce secondary pollution, help environmental protection.

Description of drawings

Figure of description is a process chart of the present invention.

The specific embodiment

A kind of method with blast furnace scrap iron in slag to prepare puron materiel, the magnetic that adopts a magnetic separation, table concentration, a chats to return to select again-heavily unite closed circuit flow process, as shown in drawings.

1. the blast furnace slag iron material is entered ball milling in the ball mill, the control ball milling time.

2. carry out two-stage screen cloth screening to going out grind materials, sieve out particle diameter greater than the oversize (thick material) of 1.18mm and particle diameter screenings (carefully material) less than 0.425mm; Particle diameter is that 0.425 to 1.18mm chats returns ball mill and continues ball milling.

3. oversize magneticly elects the high pure metal abrasive grit of MFe＞90% through the magnetic separator magnetic separation.

4. screenings gravity treatment on the fine sand shaking table sub-elects the metal iron powder of MFe＞90%.

5. iron powder drying and packaging.

6. the above metal abrasive grit of particle diameter 1.18mm can return steel mill and make steelmaking feed, and the following iron powder of particle diameter 0.425mm can be as the titanium white reduced iron powder.

Technical scheme of the present invention reclaims production line at Panzhihua Huanye Metallurgy Refuse Development Co., Ltd.'s slag iron and uses.

At first adopt the existing technology that reclaims that the above blast furnace scum of 5mm is carried out the classification recovery, reclaim respectively greater than the magnetic separation iron of the one-level iron more than the 50mm, 5-50mm and the slag iron below the 5mm (metal Ferrum content is 50.13%, and all iron content is 58.01%).Utilize the inventive method that the slag iron below the 5mm is reclaimed then, technical process is as follows::

1. the following blast furnace scum goal grinding machine ball milling of 5mm, the ball milling time is about 40min.

2. the ball milling material is carried out two-stage screen cloth screening, sieve out granularity and be greater than the 1.18mm oversize with less than the screenings of 0.425mm; Continue ball milling 0.425 return 1. the step to the 1.18mm slag iron powder.

3. oversize magneticly elects the high pure metal abrasive grit of MFe＞90% through the magnetic separator magnetic separation.

4. screenings gravity treatment on the fine sand shaking table sub-elects the metal iron powder drying and packaging of MFe＞90%.

In the screening operation of this flow process the two-stage screen cloth is set, the one-level mesh screen is told the metal abrasive grit that granularity is 1.18mm-5mm, MFe＞90%; Another grade mesh screen is told the chats of particle diameter 0.425mm to 1.18mm, and this part chats returns the ball milling operation and continues ball milling; Particle diameter sub-elects the metal iron powder of MFe＞90% less than gravity treatment on thin material (iron powder) the fine sand shaking table of 0.425mm, and with the iron powder drying and packaging.

Metal abrasive grit, iron powder typical composition are as shown in table 1

Table 1 metal abrasive grit, iron powder typical composition

Project	MFe	TFe	Mn	S	V
						Metal abrasive grit 1	97.51	/	/	/	/
Metal abrasive grit 2	95.42	/	/	/	/
						Metal iron powder 1	90.14	95.93	0.16	0.01	0.05
Metal iron powder 2	91.20	96.72	0.12	0.02	0.04

The metal abrasive grit of particle diameter 1.18mm-5mm can return steel mill and make steelmaking feed, and the following iron powder of particle diameter 0.425mm can be as the titanium white reduced iron powder.Metal abrasive grit good market prospect; Be used for the fast development of the low-grade slightly iron powder of Producing Titanium Dioxide market along with present international titanium powder industry, market potential is bigger, estimates a year increase about 20%, the domestic reduced iron powder consumption that will increase by ten thousand tons of 4-5 of only this item.Climbing steel is the major production base of China's titanium white powder, has widely with domestic many titanium powder plants and gets in touch, and several families titanium powder plant is also arranged self, and therefore, this product has the bigger market space.

Metal abrasive grit in the table 1 returns climbs the steel steel mill, and iron powder uses for climbing steel titanium industry company, and effect is good.

Claims (2)

1. method with blast furnace scrap iron in slag to prepare puron materiel adopts a magnetic separation, table concentration, a chats to return the magnetic of choosing again-heavily unite closed circuit flow process, it is characterized in that this method step in the following order realizes:

1. the blast furnace slag iron with small particle diameter enters the ball mill ball milling, goes out grind materials and enters the screening flow process;

The thick material that 2. will sieve after the flow processing enters the magnetic separation operation, and intermediate material is that chats returns ball milling operation ball milling again, and thin material enters the table concentration operation;

3. the oven dry of the micro-size fraction iron powder behind the table concentration is promptly obtained finished product.

2. a kind of method with blast furnace scrap iron in slag to prepare puron materiel according to claim 1 is characterized in that, in the screening flow process multi-stage screening operation is set.

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