KR860001498B1 - Method treatment of desulphurising agent - Google Patents

Abstract

A surface treatment soln. prepd. of coaltar, pitch or pitch oil cake in a solvent is coated on a desulfurizing agent and dried. One of or a mixt. of coaltar, pitch, and pitch oil cake is dissolved in one of petroleum ether, bezene, toluene, xylene, and pyridine, to which quicklime is added in 1-7 wt.%. The surface treatment soln. is coated on quicklime powder or bulk, and dried at room temp. Since the addition of carbon to the desulfurizing agent is unnecessary the cost is reduced.

Description

Treatment method of quicklime molten iron

The present invention relates to a method for treating quicklime (CaO) powder which is a main component of quicklime molten iron desulfurization agent.

Generally, desulfurization agents used for desulfurization treatment are classified into calcium carbide (CaC ₂ ), sodium carbonate (Na ₂ CO ₃ ), and quicklime (CaO) systems. Calcium carbide has good reaction efficiency, but a large amount of power is produced in the production of calcium carbide. Consumption is high due to the high production cost, and there is a risk of acetylene gas generation in handling. Sodium carbonate is slightly lower in reaction efficiency than calcium carbide, but has a dephosphorizing effect, but the price is higher than quicklime. Quicklime is inexpensive but has low desulfurization efficiency and reacts with moisture in the air to form calcium hydroxide (Ca (OH) ₂ ), and the cohesiveness of the powder itself makes the powder fluidized in the hopper. ) Occurs irregularly, causing clogging and pulsation of the blown tube.

On the other hand, when the blowing pressure to a high pressure to prevent the blockage and pulsation phenomenon, the molten iron is scattered or the desulfurization agent blown into the molten iron rapidly rises to the surface there is a problem that the desulfurization rate falls. As a recent method to solve this problem, a method of improving the fluidity and reaction efficiency by treating the quicklime powder surface with a silicone oil-based surface treatment agent to reduce the cohesiveness of the quicklime powder and preventing the generation of calcium hydroxide is known. have. However, in the method of treating quicklime powder with a silicone oil-based surface treatment agent, the silicon oil itself is expensive, and it is a factor of increasing the manufacturing cost of the quickener desulfurization agent because it has to be dried at 150 ° C or higher or otherwise a catalyst must be used. . The present invention aims to provide a quicklime powder surface treatment method which is inexpensive and has a similar behavior to silicon oil and can be treated at room temperature without a catalyst.

EXAMPLE

First step: Coal tar generated as a by-product in the manufacture of steel coke, or pitch pitch obtained by distilling it, medium pitch, light pitch, and pitch oil cake ) Was added to the solvent material 0.5-10wt% based on the quicklime weight ratio to prepare a treatment solution.

The solvent may be petroleum ether, benzel, toluene, xylene, landscape oil, pyridine and the like.

Second step: Wet mixing or depositing powder or bulk lime on each of the treatment solutions prepared as above to uniformly apply the treatment solution to quicklime, and then evaporate and dry the solvent at room temperature. At this time, the treatment effect is large at room temperature during evaporation and drying.

으로 나타내며, 안식각은 작을수록 유동성이 좋은 것이다.The powder treated in this way has improved fluidity than the untreated powder, and the fluidity of the powder is repose angle.

The smaller the angle of repose, the better the fluidity.

In the present invention, the angle of repose according to the addition amount of each treatment material is as follows, wherein the powder particle size is 120 mesh (mesh).

TABLE 1

* Figures in the table represent the angle of repose.

As shown in the table above, when the treatment is untreated, a repose angle of 61-63 ° appears, and as the addition amount increases, the fluidity improvement is remarkable until the addition of 3%, and it appears to be constant at 3% or more. In order to add 3% or more, it is preferable. This is because pitches, tars, pitch oil cakes, etc. are coated on the quicklime powder precipitated in these solutions, and the (CH ₃ ) _n group contained in these materials displaces water toward the outer axis. As can be seen, the poor treatment efficiency of coal tar is due to the inclusion of moisture and other impurities in coal tar, but it is not a big problem.

CaO-CaF ₂ -C type, CaO-CaF ₂ -Al type, CaO-Mg type, etc. are used for quicklime molten iron desulfurization.Also, Al and Mg are expensive, so CaO-CaF ₂ -C type is usually used. ) Usually adds graphite, anthracite, charcoal and powdered coke. However, the material used as the treatment agent in the present invention has a side effect that does not require the addition of carbon separately to the desulfurization agent containing a carbon component. In other words, when 5% of the pitch oil cake is added, the carbon content in the desulfurization agent is 3.8%, and in order to obtain a carbon addition effect of about 5%, 7% is added.

As such, the present invention uses coal tar and pitches produced as by-products in the manufacture of coke as a treatment agent, and can be treated at a low price since it can be processed at room temperature without a catalyst, and additionally, additionally adding carbon to the desulfurization agent. Is a very large and practical invention.

Claims (1)

Quicklime powder or bulky lime is added to a solution of coal tar, pitches, and pitch oil cakes alone or in combination with a quicklime weight ratio of 1-7wt% to solvents such as petroleum ether, benzene, toluene, xylene, landscape oil, and pyridine. The method for treating quicklime soluble desulfurizing agent, characterized in that the solvent is evaporated and evaporated at room temperature after uniform application.