CN103255284A

CN103255284A - Method for processing and utilizing low-quality iron ore powder

Info

Publication number: CN103255284A
Application number: CN2013102007316A
Authority: CN
Inventors: 余建平; 李淑宝; 曹学明; 蒋建华
Original assignee: Nanjing Iron and Steel Co Ltd
Current assignee: Nanjing Iron and Steel Co Ltd
Priority date: 2013-05-27
Filing date: 2013-05-27
Publication date: 2013-08-21

Abstract

The invention discloses a method for processing and utilizing low-quality iron ore powder. The method comprises the following steps of: mixing quick lime blocks with low-quality raw iron ore, and stirring and overturning, thereby obtaining a semi-finished product; overturning the semi-finished product three times, and braising the material, thereby obtaining iron ore powder; and screening the obtained iron ore powder on a mesh sieve having 50 mm sieve meshes, thereby obtaining the undersize finished product ore and completing the processing of the low-quality iron ore powder. The method is capable of solving the problem that the iron ore powder cannot be transported and blended, the processing cost of the method is far lower than that of tedding and drying and the processing time is also far shorter than that of tedding. The obtained iron ore powder is blended with an even mixture by a proportion of less than 10%, and the magnesium-aluminum ratio of blast-furnace slag is guaranteed in a normal range. At the same time, the ore blending cost can be greatly reduced and the cost of the iron liquid is reduced consequently; and simultaneously, the blaster furnace is guaranteed to operate stably and the quality of the iron liquid is ensured.

Description

A kind of processing of low-quality powdered iron ore and using method

Technical field

The invention belongs to field of metallurgy, relate to a kind of powdered iron ore, specifically a kind of processing of low-quality powdered iron ore and using method.

Background technology

The former ore resources of low-quality iron ore, though cheap, generally speaking, the iron grade is all very low, and moisture is higher, and aluminum oxide is higher, and table 1 is the basic physical and chemical composition of the former ore resources of low-quality iron ore, following several respects reason causes it can't carry out industrial production:

1, can't transport at belt, such ore deposit has the high characteristics of toughness, transports at belt, causes slipping of belt easily.

2, can't directly prepare burden in feed bin, such ore deposit has the high characteristics of toughness, stops up feed opening easily.

3, can't be on the mixing stockpile stone, such ore deposit is bonded to bulk, can tumble from mixing stockpile top, causes stone portion even.

4, such ore deposit is contained greater than the calcareous stone more than the 50mm, uses in the sintering again.

5, such ore deposit is salic higher, if unreasonable use can cause the blast furnace instability.

6, traditional method mainly is to ted and dry, though can solve transportation and batching difficult problem, the treatment time is long and cost is higher, and loss is bigger.

Table 1: the basic physical and chemical composition of the former ore resources of low-quality iron ore:

Figure 2013102007316100002DEST_PATH_IMAGE001

Summary of the invention

In order to overcome the problem that prior art exists, the processing and the using method that the purpose of this invention is to provide a kind of low-quality powdered iron ore, this method can solve the problem that powdered iron ore can't be transported and prepare burden, and tooling cost is lower than and teds and dry, and is significantly shorter than process period and teds; Can reduce greatly simultaneously and join the ore deposit cost, finally reduce molten iron cost, guarantee the blast furnace stable smooth operation simultaneously, guarantee molten steel quality.

The objective of the invention is to be achieved through the following technical solutions:

A kind of working method of low-quality powdered iron ore is characterized in that this method may further comprise the steps:

1) use caustic lime block to mix with low-quality iron ore raw ore, stir, upset obtains the work in-process material;

2) the work in-process material overturn, boil in a covered pot over a slow fire material, obtain powdered iron ore; The work in-process material is carried out three upsets, stewing material, wherein, upset for the first time, stewing material 28 ± 1 hours, upset for the second time, stewing material 48 ± 1 hours, time upset for the third time, stewing material 46 ± 1 hours obtain powdered iron ore.

3) with the powdered iron ore that obtains, sieve at 50mm sieve aperture mesh screen, obtaining screen underflow is the finished product ore deposit, finishes the processing of low-quality powdered iron ore.

The application in the finished product ore deposit that a kind of working method of low-quality powdered iron ore obtains is joined the people in the mixing material by the proportioning below 10%, guarantees that wherein the magnalium of blast-furnace slag is than in normal range.

Principle of the present invention is: use caustic lime block to return mine with low-quality iron ore raw ore and pelletizing and mix, CaO is combined with H2O forms Ca (OH) 2, reduce mechanical water content, low-quality powdered iron ore after will processing again, sieve at 50mm sieve aperture mesh screen, screen overflow is calcareous stone and other industrial refuses, and screen underflow is the finished product ore deposit, and the finished product ore deposit can enter belt transportation and sintered material system.Table 2 is the low-quality processing powder physical and chemical composition tables that obtain.

Table 2: low-quality processing powder physical and chemical composition

Table 3 is physical and chemical composition contrast tables before and after the processing, the invention has the beneficial effects as follows:

CaO amount significantly rises 6.11%, because using the cause of limestone block in the course of processing, CaO down in the sintering circuit must with addition of, now add in advance, but down to the operation decrement.

After processing, moisture declines to a great extent, and raw material granularity is even, is loose shape, and no bulk reaches 100% less than the 10mm grade, can transport at belt, and blanking can blockage phenomenon in the feed bin.

Join the people in the mixing material by the proportioning below 10%, stable without any influence to blast furnace, the capacity factor of a blast furnace can reach 2.48t/(m3h at present).

Every increase by 1% low-quality processing powder, molten iron cost can reduce by 1.5 yuan of/ton iron.

Table 3: physical and chemical composition contrast before and after the processing

The present invention utilizes the cheap former ore resources of low-quality iron ore, through after the simple processing treatment, substitute the high Australia ore deposit of price by a certain percentage, by forming agglomerate after the sintering process, under the prerequisite that guarantees the blast furnace stable smooth operation, finally can significantly reduce molten iron cost, improve the profitability of enterprise.

Description of drawings

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

Embodiment

A kind of working method of low-quality powdered iron ore is example with low-quality Indonesia powder (raw ore),

The concrete implementation record of low-quality Indonesia powder

1, the morning on the 11st March in 2013,8:30 Indonesia powder was unloaded a ship, transhipment raw material plant processing site, and March in 2013, afternoon on the 11st, the 17:00 caustic lime block entered processing site (covering with waterproof canvas); The morning on the 12nd March in 2013,8:45 began Indonesia powder processing operation, tiled, mixed ash, turns, beats heap and process the about 720t(of compound and cover with waterproof canvas to 12:00 accumulative total).

2,13:30 processing in afternoon on the 13rd March in 2013 compound turns, beats heap for the first time; After 28 hours, the processing compound turns, beats heap for the second time, and the range estimation processing effect is remarkable; After 48 hours, the processing compound turns for the third time, after 46 hours, sieves, and Indonesia's processed finished products powder is transported to specifies the place to stack (covering with waterproof canvas), and inspection by sampling, and first Indonesia's powder machines.Table 4 is Indonesia's powder and Indonesia's processed finished products powder contrast table.

3, by Indonesia powder processing job procedure carry out stone, spread ash, turn, Da Dui and the cycle operation that turns, sieve for three times.

4, join people's mixing material sintering, ironmaking.

Table 4: Indonesia's powder and Indonesia's processed finished products powder contrast table:

Figure 2013102007316100002DEST_PATH_IMAGE005

Claims

1. the working method of a low-quality powdered iron ore is characterized in that this method specifically may further comprise the steps:

1) use caustic lime block and low-quality iron ore raw ore mixed dehydration, stir, upset obtains the work in-process material;

2) the work in-process material overturn, boil in a covered pot over a slow fire material, obtain powdered iron ore;

2. the working method of low-quality powdered iron ore according to claim 1, it is characterized in that: step 2) in, the work in-process material is carried out three upsets, stewing material, wherein, upset for the first time, stewing material 28 ± 1 hours, upset for the second time, stewing material 48 ± 1 hours, time upset for the third time, stewing material 46 ± 1 hours obtain powdered iron ore.

3. the application in the finished product ore deposit that obtains of the working method of the described low-quality powdered iron ore of claim 1 is joined the people in the mixing material by the proportioning below 10%, guarantees that wherein the magnalium of blast-furnace slag is than in normal range.