SU939568A1 - Pulverulent dephosphorizing mix - Google Patents

Description

(ii) POROQUALLY DEFOSPHORATING The invention relates to ferrous metallurgy, namely to steel production in electric furnaces using powdered materials to intensify the deformation process - in melting and in the oxidation period of melting. In order to intensify the process of dephosphorization of iron-carbon melts in the production of steel in electric arc furnaces, powder-like mixtures of various compositions are used. Powdered oxidative mixtures of tl from lime and iron ore, taken in the ratios 1: 1, 9: 1,, 7: 3, 3: 7, are known. With an increase in the proportion of iron oxides, the rate of steel decarburization increases, but the dephosphorization rate decreases. Mixtures containing lime and iron ore in the proportions j: 7: 3 are considered optimal. A known powdered oxidation mixture containing 70% lime. MIXTURE 20% iron ore and 10 fluorspar, having a high dephosphorizing capacity 2}. However, this mixture contains a scarce and expensive component — powdered fluorspar, which, when widely used, makes it difficult. The closest is a powdered oxidative mixture containing A8-63% lime, 16-21% chamotte and 16-36% iron ore, with a weight ratio of lime to chamotte 3iO-3,2. At a low cost, this mixture has a fairly high dephosphorizing capacity, which makes it possible to produce unalloyed steel with a moderately low concentration of phosphorus GZ. However, when smelting structural alloyed steels by the method of melting waste containing chromium, nickel, manganese and other elements, the oxidative potential of this mixture

3.9395684

insufficient for effective removal — All materials grind and sift

phosphorus from a metal melt — to obtain a fraction of not more than G mm, then mechanically mix and

The purpose of the invention is to produce high for 1 h, it is calcined with BOO-BZO S, the slag's dephosphorizing capacity. S Purging the liquid metal prepared by smelting structural steel mixtures (in an oxygen flow) using a method of remelting waste, and using a nickel alloy of aeration metal type at pressure in

This goal is achieved by having a pneumatic heater of at least 6 atm.

that the powder is dephosphorized to the temperature of the metal before starting the mixture for refining the doped powder purge 15 P-15bO ° C. Permeability of structural steels, with the duration of powder blowing through

holding iron ore, lime, and sha — all cases x 5 min; mot, additionally contains oxide

Nickel in the following ratio of com- is the content of the main elements in ponente, weightD: metal before blowing,%: carbon

Iron ore 10-250,62-1,28, chromium O, 30-1,67, manganese

Nickel oxide 15-300,22-0,72, silicon 0,13-0, + 0, nickel 5-20 well 0.32-0.5, phosphorus 0.012-0.022.

Lime Elsejo

Claims (3)

The dephosphorus mixtures were prepared barely. The table gives the results in the following way: structural steel. As can be seen from the table, the introduction of the composition of a mixture of nickel oxide can increase the oxidative potential of the mixture and thereby increase the dephosphorizing capacity of the slag that is formed, as well as doping the metal with nickel. A decrease in the amount of nickel oxide in the mixture of less than 5% leads to a decrease in the oxidizing potential of the mixture, which worsens the process of dephosphorization. An increase in nickel oxide of more than 3 reduces the lime content in the mixture, resulting in a reduced basicity of the slag, as well as a danger of being in chemical analysis of nickel. When the content of fireclay in the mixture is less than 3, the liquid mobility of the slag formed deteriorates, the activity of iron oxide in it decreases, and the oxidative potential of the mixture decreases. An increase in the content of fireclay in the mixture over 20% does not lead to an increase in the degree of dephosphorization and increase in the liquid mobility of the slag. The change in the amount of iron ore in the mixture is less than 10% and more than 25% with water in the first case, to a decrease in the slag oxidation and thereby deterioration of the process of dephosphorization, secondly, to a decrease in the amount of lime in the mixture and a decrease in the basicity of the slag, which also worsens the conditions of dephosphorization. DETAILED DESCRIPTION OF THE INVENTION Powdered dephosphorizing mixture for refining nickel-alloyed structural steels containing lime, iron ore and chamotte, characterized in that, in order to obtain a high dephosphorizing ability of slag and simultaneous alloying of the metal with nickel, it additionally contains nickel oxide, with the following ratio components, wt.%: Nickel oxide 15 30 Iron ore 10-25 Shamot5-20 Lime Other Sources of information taken into account during the examination 1. Bulletin of VNIIITEICHM, 197, IT 22, c.kk. . 2. Sidorenko M.F. Theory and practice of blowing metal powders. M., Metallurgists, 1E78, pp. 161-163. 3. USSR author's certificate №, cl. C 21 C 7/00, 1978.