CN1199099A

CN1199099A - Desulfurizing slag modifier

Info

Publication number: CN1199099A
Application number: CN 98100567
Authority: CN
Inventors: 李宏鸣; 王涛; 石洪志; 张凯
Original assignee: Baoshan Iron and Steel Co Ltd
Current assignee: Baoshan Iron and Steel Co Ltd
Priority date: 1998-02-24
Filing date: 1998-02-24
Publication date: 1998-11-18
Anticipated expiration: 2018-02-24
Also published as: CN1062019C

Abstract

A modifying agent for improving the flowability of molten iron desulfurizing slag whose main component is CaO contains Na2CO3 (35-50 wt.%), SiO2 (35-50 wt.%), CaF2 (8-15 wt.%). In the condition that the slags amount is up to 11 kg or more per ton of iron and the content of CaO in the desulfurizing slag is up to 42.3-71.9 wt.%, the modifying agent can congruent melt with desulfurizing slag to form modified desulfurizing slag with low melting point and good flowability. The Na2O3 as alkaline compound can increase desulfurizing effect. Its advantages are low cost and widely available raw materials.

Description

A kind of desulfurizing slag modifier

The present invention relates to a kind ofly in order to improve the desulfurizing slag modifier of desulfurizing slag of hot metal flowing property, being particularly suitable for opposing with CaO is that the desulfurization slag of major ingredient is carried out upgrading.

In the hot metal pretreatment process, owing to produce high-melting-point, full-bodied desulfurization slag, and desulfurization container accumulated slag and dry slag appear, both reduced the capacity of desulfurization container, can cause back the sulphur phenomenon again, when serious even influence normally carrying out of desulfurization production.The clear 55-47310 of Japanese Patent " the easy flux of foundry ladle slag blanket " discloses a kind of desulfurization slag solidified modification agent that prevents, its Chemical Composition is (weight): SiO ₂50-70%, Al ₂O ₃20-36%, Na ₂O+K ₂O10-15%.Under the situation of the mean height slag amount of bringing into iron 1.67kg per ton approximately, doctor solution consumption iron 1.23kg per ton approximately, add-on with iron 0.4kg per ton approximately adds modification agent in the desulfurization container before desulfurization, by reacting the flowability that generates the low melting point slag and improve slag by the thermit reaction additional heat with desulfurization slag, make the deslagging operation smoothly, the molten iron recovery rate improves.The subject matter of its existence is: (1) upgrading is limited in one's ability.When calcium oxide content is higher in the slag after the blast furnace slag amount of bringing into is than big and desulfurization, with SiO ₂And Al ₂O ₃Be the modification agent of major ingredient, the ability that reduce the desulfurization slag fusing point, improves liquidity is just inadequate; (2) because this with SiO ₂, Al ₂O ₃For the modification agent of major ingredient is strongly-acid, the basicity of sweetening agent is reduced, influence sweetening effectiveness; (3) Al in this modification agent ₂O ₃After adding the reaction of aluminium powder and ferric oxide, obtain.Aluminium powder costs an arm and a leg, modification agent cost height.

The purpose of this invention is to provide a kind ofly under the big feelings of the blast furnace slag amount of bringing into, can significantly improve the flowability of desulfurization slag, promote desulfurization, and lower-cost desulfurizing slag modifier.

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

A kind of desulfurizing slag modifier, the Chemical Composition of its finished product are (weight): Na ₂CO ₃35-50%, SiO ₂35-50%, CaF ₂8-15%, surplus is Fe ₂O ₃, P ₂O ₅With other unavoidable impurities.

From chemical analysis as can be known, with Na ₂CO ₃, SiO ₂To generate fusing point with the desulfurization slag congruent melting based on CaO low for the modification agent of major ingredient, the slag of good fluidity.Soda Na ₂CO ₃More can participate in desulfurization directly as basic cpd, play the promotion desulfidation.But Na ₂CO ₃Consumption is crossed conference and is caused environmental pollution and equipment corrosion, so Na in the finished product ₂CO ₃Content should not surpass 50%.SiO ₂Be mainly used to reduce the desulfurization slag fusing point, but,, then can reduce slag basicity, influence sweetening effectiveness if surpass 50% because it is an acidic cpd, and the content in the product is difficult for too high.CaF ₂Be widely used as fusing assistant in metallurgy, it can make the fusing point of slag significantly reduce.Simultaneously, data information all proves with practice: fluorion can destroy the chemical bond of Calucium Silicate powder, improves the utilization ratio of calcium oxide in the sweetening agent, thereby improves desulfuration efficiency.But CaF ₂Anti-material is had stronger corrodibility, and therefore, content is controlled in the lower level of 8-15% in the finished product.In addition, scene and laboratory test all prove: this modification agent is appropriate to the improvement of desulfurization slag flowability.Otherwise, can cause when awarding iron after the desulfurization, slag is too much under the molten iron, influences the postorder quality of production.

Below in conjunction with embodiment the present invention is described in detail.

Desulfurizing slag modifier of the present invention is by behind the soda of granularity 0.5-3.0mm, silica sand, the fluorite uniform mixing, the product that oven dry is made.

Embodiment 1:

The composition of product consists of (weight): Na ₂CO ₃45.24%, SiO ₂45.62%, CaF ₂8%.

At the molten iron Intake Quantity is 271 tons (on average), under about 3 tons of (on average) situations of the blast furnace slag amount of bringing into, with above-mentioned 250kg modification agent, before desulfurization is handled, is added by the metal mixer car mouth.

Add behind this modification agent the physicochemical property of desulfurization slag and see attached list 1.

Embodiment 2:

The composition of product consists of (weight): Na ₂CO ₃49%, SiO ₂35%, CaF ₂15%.

Under all identical situation of molten iron Intake Quantity, the blast furnace slag amount of bringing into,, before desulfurization is handled, add by the metal mixer car mouth with above-mentioned 350kg modification agent with embodiment 1.

Embodiment 3:

The composition of product consists of (weight): Na ₂CO ₃36.9%, SiO ₂50%, CaF ₂12%.

Molten iron Intake Quantity, the blast furnace slag amount of bringing into, modification agent add-on and adding method are all identical with embodiment 1.

The advantage that the present invention compared with prior art has is: to the upgrading energy of desulfurization slag Power is strong. More than the slag amount of bringing into was up to every ton of iron 11kg, CaO content reached in the desulfurization slag 42.3 in the situation of～71.9% (weight), reduced softening point, the fusing point and sticking of desulfurization slag Degree has improved the flowability of desulfurization slag greatly, and the average deslagging amount of bicycle is by original 1.38 tons Increase to 2.26 tons, improved 63.8%, substantially can all topple over away during deslagging, avoided The residual packing of desulfurization slag in torpedo hot metal mixer car improved operating environment, improved the operation effect Rate. Owing to adopted the higher alkaline compound N a of content in the modification agent₂CO ₃, can directly join With desulfurization desulfuration efficiency is improved, desulfurization agent unit consumption reduces. From subordinate list 1, as seen, add Enter in the desulfurization slag behind the modification agent of the present invention to contain a certain amount of sodium, theory and practice is all demonstrate,proved Bright, a certain amount of sodium ion is extremely strong desulfurization agent in the slag, and this modification agent tool also is described thus The desulfurization of promotion effect is arranged. The raw materials used price of modification agent is low, easily obtain, thereby modification agent becomes This is low.

Subordinate list 1, add and the desulfurization slag physicochemical property table that does not add modification agent

		Do not add modification agent	Embodiment 1	Embodiment 2	Embodiment 3
		Do not add modification agent	Embodiment 1	Embodiment 2	Embodiment 3	Mainly change heavily and measure into % part	CaO	42.3～71.9	14～46	12～40	13～38
SiO ₂	5.3～16.7	10.3～29.8	13.2～29.3	17.7～31.9			CaO	42.3～71.9	14～46	12～40	13～38
SiO ₂	5.3～16.7	10.3～29.8	13.2～29.3	17.7～31.9	Al ₂O ₃		2.5～7.0	1.8～11.4	1.6～11.6	1.4～11.7
MgO	0.1～0.9	0.29～4.3	0.28～4.1	0.25～4.6	Al ₂O ₃		2.5～7.0	1.8～11.4	1.6～11.6	1.4～11.7
MgO	0.1～0.9	0.29～4.3	0.28～4.1	0.25～4.6	FeO		2.21～22.9	6.6～18.6	5.2～14.6	4.7～13.5
Na		0.16～1.72	0.45～2.23	0.23～1.54	FeO		2.21～22.9	6.6～18.6	5.2～14.6	4.7～13.5
Na		0.16～1.72	0.45～2.23	0.23～1.54	S		0.51～0.97	0.89～0.99	0.89～0.99	0.89～0.99
Softening point ℃		1355～1490	1205～1295	1200～1285	S		0.51～0.97	0.89～0.99	0.89～0.99	0.89～0.99	1220～1310
Softening point ℃		1355～1490	1205～1295	1200～1285	Fusing point ℃		1360～1495	1210～1300	1205～1290	1225～1320	1220～1310
Mobile ℃		1365～1500	1215～1305	1210～1295	Fusing point ℃		1360～1495	1210～1300	1205～1290	1225～1320	1230～1325
Mobile ℃		1365～1500	1215～1305	1210～1295	1400 ℃ of viscosity Pa.S		0.55～0.70	0.20～0.35	0.20～0.30	0.25～0.35	1230～1325

Claims

1. desulfurizing slag modifier, it is characterized in that: product contains Na ₂CO ₃35-50% (weight), SiO ₂35-50% (weight), CaF ₂8-15% (weight), surplus is Fe ₂O ₃, P ₂O ₅With other unavoidable impurities.