Pre-molten low-melting point composite calcium oxide desulfurizer and its prepn.

Abstract

The invention discloses a kind of premelt-type, low-melting point, calcium oxide complex desulfurizing agent and its preparation method, which is prepared according to the below components and proportino (weight): calcium oxide 70-90%, calcium fluoride 3-20% and catalyst 0-10%. In advance perform passivating treatment on calcium oxide, then mix all the components according to the required proportion, smelt them in the high-temperature stove, and then by crashing prepare the particle-shape or powder-shape desulfurizing agent. By the premelting treatment, the melting point of desulfurizing agent lowers to 1250-1400 centigrade, which obviously raise its desulfurizing rate in the molten iron (molten steel) and shortens the reactive time and production cycle; on the condition of reaching the same desulfurizing effect, its dosage is reduced by over 50% compared with the mechanical mixed materials.

Description

1. Technical field [0001] The invention relates to a desulfurizer used in the industrial production of molten iron (molten steel) and a preparation method thereof, in particular to a pre-melted low melting point composite desulfurizer and a preparation method thereof. 2. Background technology [0002] Existing desulfurizers are generally mechanical mixtures. Its main defect is that the active ingredients therein, such as calcium oxide, etc., have a high melting point (generally at 1900-2200°C), resulting in poor activity during use, and the effective utilization ratio is too low, generally around 10%. However, about 90% of the unreacted components are discharged in the form of waste residue, causing serious pollution to the environment. At the same time, due to the high melting point of the mechanical mixture, it is not easy to dissolve, which prolongs the reaction time of the desulfurization process and reduces the production efficiency to a certain extent. On the other h...

AI Technical Summary

Problems solved by technology

Its main defect is that the active ingredients, such as calcium oxide, have a high melting point (generally at 1900-2200°C), resulting in poor activity during use, and the effective utilization ratio is too low, generally around 10%.

And about 90% of the unreacted components are discharged in the form of waste residue, causing serious pollution to the environment

At the same time, due to the high melting point of the mechanical mixture, it is not easy to dissolve, which prolongs the reaction time of the desulfurization process and reduces the production efficiency to a certain extent.

On the other hand, the mechanical mixture contains more exhaust components, such as NaCl, BaCO 3 、Na 2 CO 3 , CaCl 2 etc. Although these components have a certain catalytic effect on desulfurization, they release a large amount of harmful gases such as Cl during use 2 , CO, CO 2 etc., not only seriously pollute the working environment, but also cause public nuisance