CN104404176A

CN104404176A - Recycling method of refining white slag

Info

Publication number: CN104404176A
Application number: CN201410572904.1A
Authority: CN
Inventors: 李惠勇
Original assignee: Wuyang Iron and Steel Co Ltd
Current assignee: Wuyang Iron and Steel Co Ltd
Priority date: 2014-10-24
Filing date: 2014-10-24
Publication date: 2015-03-11

Abstract

The invention discloses a recycling method of refining white slag, the method is as follows: the white slag is added, before a slagging agent, into the molten steel which is refined or ready to refine; refined lime melting point is 2614DEG C, only after the addition of fluorite, aluminum bauxite and other slagging agent, the melting point can be reduced for slow slagging, the fluorite dosage is about 2kg per ton of steel, aluminum bauxite dosage is about 3kg per ton of steel; and after the recycled white slag is added, the part of the material can be completely or partially replaced. The method makes full use of the low melting point characteristic of the refining white slag, the rate of slag formation is improved, refining energy consumption is reduced, the problems of high treatment cost and large environmental pollution of the refining white slag can be effectively solved, refining electricity and refining lime and fluorite and other slagging agent consumption can be reduced, the molten steel quality is not reduced, at the same time, the method can reduce waste emissions, reduce air pollution, and effectively reduce the production cost, and has the characteristics of energy saving and environmental protection and low cost.

Description

A kind of recoverying and utilizing method of refining white slag

Technical field

The present invention relates to a kind of reuse method of Using Metallurgical Solid Wastes, especially a kind of recoverying and utilizing method of refining white slag.

Background technology

China's iron and steel production capacity has reached 900,000,000 tons, and along with user progressively improves the requirement of iron and steel inner quality, refining has become indispensable operation, will produce a large amount of solid waste refining white slags.The wet efflorescence in atmosphere of refining white slag, produces very large dust pollution to environment.The processing mode of traditional refining white slag is buried, and produces a large amount of transports, landfill expense.In LF refining in earlier stage, be rapid slagging, submerged arc heats up, and must add slag former fluorite or bauxitic clay, fluorite produces harmful fluoro-gas after disassembly, and bauxitic clay then causes the waste of resource.

Summary of the invention

The technical problem to be solved in the present invention is to provide a kind of recoverying and utilizing method of the white slag of refining effectively.

For solving the problems of the technologies described above, the technical solution used in the present invention is: described white slag joined before slag former just refining or prepare refining molten steel in.

White slag of the present invention is liquid white slag or solid-state white slag; Described liquid white slag directly adds in the molten steel preparing refining; Described solid-state white slag, after cooling, pulverizing, screening, pelletizing, joins in molten steel in refining early stage.

The total amount that adds of liquid white slag of the present invention and solid-state white slag is no more than 6kg/ ton steel.

Solid-state white slag of the present invention directly adds after refining seat bag power transmission.

It is that the solid-state of 1kg/ ton steel and liquid white slag substitute the fluorite of 0.5kg/ ton steel and the lime of 0.5kg/ ton steel that the present invention often adds total amount.

The Task-size Controlling of solid-state white slag of the present invention is at 10 ~ 80mm.

The beneficial effect adopting technique scheme to produce is: (1) refining stone fusion point of ash is at 2614 DEG C, only after adding the slag former such as fluorite, bauxitic clay, its fusing point could be reduced, slowly slagging, fluorite consumption is about a ton steel 2kg, and bauxitic clay consumption is about a ton steel 3kg; After adding the white slag of recovery, this portion of material can partly replace.

(2) refining desulfuration efficiency can be improved adding of white slag, and decrease refining lime consumption.Because a utilization ratio of calcium system refining slag desulfurization is lower, the adding of white slag make it act on and fully played, when ton steel adds the white slag of 5kg, identical lime consumption, it is lower by 0.002 ~ 0.005% than not adding refining white slag that sulphur content in molten steel is finished in refining.

(3) owing to decreasing, slag melting speed is in earlier stage slow, the bad calorific loss caused of submerged arc, and improve molten steel heating speed, ton steel about can reduce refining power consumption 2 ~ 3kwh;

In sum, the present invention makes full use of the low-melting feature of refining white slag, improves slagging speed, reduces refining power consumption, efficiently solves that the processing costs of refining white slag is high, the large problem of environmental pollution, and reduces the slag former consumption such as refining electricity and refining lime, fluorite; While not reducing quality of molten steel, both reduced the discharge of solid waste, alleviated topsoil, effectively reduced production cost again; There is energy-saving and environmental protection, feature that cost is low.

Embodiment

Below in conjunction with specific embodiment, the present invention is further detailed explanation.

Refining white slag in the recoverying and utilizing method of this refining white slag is divided into liquid white slag and solid-state white slag; Liquid white slag comprise be poured liquid white slag in rear ladle and vacuum before the white slag that removes; The main component of white slag is TCa:35 ~ 40%, Al ₂o ₃: 25 ~ 35%, SiO ₂: 7 ~ 17%, other MgO, MnO are a small amount of, and fusing point is about 1350 DEG C-1450 DEG C.

Present method sends out concrete steps: (1) described liquid white slag directly adds in the molten steel preparing refining, direct slagging; Then enter LF refining, then add lime and reductor in batches;

(2) described solid-state white slag need broken in relatively airtight, dry environment, screening, stops the pollution of airborne dust to environment, brings moisture into simultaneously and work the mischief to steel after avoiding the white slag moisture absorption; Task-size Controlling is at 10 ~ 80mm;

(3) described solid-state white slag joins in molten steel in refining early stage; Need add before adding the slag former such as fluorite, bauxitic clay, avoid the later stage to add and cause refinery scum excessively rare, and cause being mingled with adsorptive power deficiency; Before adding, need steel ladle bottom argon blowing good, freeboard meets more than 500mm; Solid-state white slag preferably directly adds after refining seat bag power transmission, and then adds lime and reductor in batches;

(4) total amount that adds of liquid white slag and solid-state white slag is no more than 6kg/ ton steel; Often add the refining white slag (liquid white slag and solid-state white slag total amount) of 1kg/ ton steel, think the amount of being routinely added to that should reduce 0.5kg/ ton steel fluorite and 0.5kg/ ton steel lime; When fluorite consumption is less than the alternative amount of refining white slag, then do not add fluorite.

Embodiment 1: the recoverying and utilizing method (steel grade Q345B 120 tons of molten steel/stoves) of this refining white slag, concrete steps are as follows:

(1) large bag temperature 1558 DEG C is finished in just furnace tapping, and large bag Argon is good, and freeboard 600mm, directly pours stove into and be poured liquid refining white slag 720kg, samples C:0.063%, S:0.037% before not pouring refining slag into;

(2) LF refining: add lime 700kg, silicomanganese 1800kg, calcium carbide 300kg, silicon carbide 50kg in 10 minutes after refining seat bag power transmission, slag is yellowish-white, cuts electrical measurement temperature 1547 DEG C, feeding aluminum steel 600m, Argon sampling in 1 minute: C:0.085%, S:0.029%; Continue power transmission 15 minutes, add lime 400kg successively, silicomanganese 550kg, ferrosilicon powder 100kg, cut electrical measurement temperature 1608 DEG C, Argon sampling in 2 minutes: C:0.13%, S:0.008%; Continue power transmission 7 minutes, add lime 80kg, cut electrical measurement temperature 1636 DEG C, sampling: C:0.14%, S:0.004%; LF refining process terminates; The contrast of cost consumption index sees attached list 1.

Embodiment 2: the recoverying and utilizing method (steel grade Q345B 120 tons of molten steel/stoves) of this refining white slag, concrete steps are as follows:

(1) large bag temperature 1549 DEG C is finished in just furnace tapping, and large bag Argon is good, freeboard 500mm, sampling C:0.067%, S:0.042%;

(2) solid-state refining white slag 480kg is first added after LF refining seat bag power transmission, then lime 600kg is added in 12 minutes, silicomanganese 1800kg, calcium carbide 300kg, silicon carbide 50kg, slag is yellowish-white, cuts electrical measurement temperature 1550 DEG C, feeding aluminum steel 600m, Argon sampling in 1 minute: C:0.078%, S:0.031%; Continue power transmission 15 minutes, add lime 500kg successively, silicomanganese 600kg, ferrosilicon powder 80kg, cut electrical measurement temperature 1602 DEG C, Argon sampling in 2 minutes: C:0.147%, S:0.009%; Continue power transmission 8 minutes, add lime 200kg, cut electrical measurement temperature 1639 DEG C, sampling: C:0.16%, S:0.005%; LF refining process terminates; The contrast of cost consumption index sees attached list 1.

Comparative example: adopt routine not add white slag technique and produce, the cost consumption of common process and present method technique contrasts in table 1.

Table 1: cost consumption index is shown in contrast

Concrete contrast:

For fluorite, use and reclaim white slag heat, fluorite 2kg saved by ton steel, refining electricity about 3 degree, by 2013 yearly plan valencys, 900 yuan/ton, fluorite, refining electricity 0.67 yuan/degree, ton steel can reduce refining cost: 3*0.67+2*0.9=3.81 unit, calculates, year synergy 3,810,000 yuan by annual production 1000000 tons of steel.As can be seen here, effectively reduce production cost, enterprise creates good Social benefit and economic benefit.

Claims

1. a recoverying and utilizing method for refining white slag, is characterized in that: described white slag joined before slag former just refining or prepare refining molten steel in.

2. the recoverying and utilizing method of a kind of refining white slag according to claim 1, is characterized in that: described white slag is liquid white slag or solid-state white slag; Described liquid white slag directly adds in the molten steel preparing refining; Described solid-state white slag, after cooling, pulverizing, screening, pelletizing, joins in molten steel in refining early stage.

3. the recoverying and utilizing method of a kind of refining white slag according to claim 2, is characterized in that: the total amount that adds of described liquid white slag and solid-state white slag is no more than 6kg/ ton steel.

4. the recoverying and utilizing method of a kind of refining white slag according to claim 2, is characterized in that: described solid-state white slag directly adds after refining seat bag power transmission.

5. the recoverying and utilizing method of a kind of refining white slag according to claim 2, is characterized in that: often adding total amount is that the solid-state of 1kg/ ton steel and liquid white slag substitute the fluorite of 0.5kg/ ton steel and the lime of 0.5kg/ ton steel.

6. the recoverying and utilizing method of a kind of refining white slag according to claim 2-5 any one, is characterized in that: the Task-size Controlling of described solid-state white slag is at 10 ~ 80mm.