SU1680776A1 - Refinery slag mixture for dernosphorating of metal melts and method for its manufacturing - Google Patents

Abstract

This invention relates to special refining slags for deep dephosphorization of highly phosphorous carbonaceous metal melts in ferrous metallurgy, ferroalloy production, mechanical engineering (cast iron). The purpose of the invention is to reduce the cost of the mixture and prevent the occurrence of refosporation. This goal is achieved by the fact that the mixture additionally contains alumina in the following ratio of components, wt.%: CaO 17-29, CaC 63-77; A1aOz 6-120, and to obtain a refining mixture, waste titanium-magnesium production is additionally introduced into the furnace in the following ratio of calcium chloride, lime, and chloride waste of titanium production (1.12-4.0) :( 0.14-0.7 ): 1. 2 sec. f-ly. 1 tab.

Description

This invention relates to refining special slags for the dephosphorization of highly phosphorous carbon melts of metals (carbon steels, cast iron, ferroalloys) produced in ferrous metallurgy, ferroalloy production, mechanical engineering (cast iron).

The purpose of the invention is to reduce the cost of the mixture and reduce the appearance of re-phosphorization.

Cheaper prices are achieved by using a chloride waste from the production of non-ferrous metals to prepare a refining mixture.

Reduction of refosporation (reverse transition of phosphorus to metal) is achieved

an increase in the proportion of CaO and limiting the content of AI2O3.

Choose the following ratio of components, wt.%: Cao 17-29; CaCI 63-77; A12Oz6-12.

The refining mixtures are prepared by fusing from chloride wastes. Ust-Kamenogorsk titanomagnium plant with a general molecular formula of ZSaO CaCbAlaOa or a mass ratio (wt.%) 47: 27.5: 25.5, respectively, with the addition of commercial CaCfe and crushed CaO from a fluidized bed kiln.

The composition of the mixtures are given in the table.

About 00

about VI

J

ON

Melting is carried out in an induction furnace with a graphite crucible with a capacity of 50 kg. The alignment is carried out in accordance with the compositions shown in the table. So, for mixture 5 according to the calculation of the mixture, wt.%: Cao 29; CAC 63 and A120 3, take, May. including: chloride waste 1; CaO 0.53; CaCIa 1.82. The refining mixture is heated to the temperature of the metal to be treated (1320 ° C) and poured into the receiving graphite crucible. The weight of the mixture is 5% by weight of the metal. Then cast iron with Riesch content of 0.281 wt.% And a temperature of 1320 ± 20 ° C is poured into the liquid mixture. After 20 minutes of exposure, the slag is drained and a metal sample is taken for phosphorus analysis. From the final phosphorus content in the metal Rcon (%), the degree of dephosphorization is calculated by the formula:

Gy - (% RISH-% RKOH) yuo / t ™.

The table shows the results of dephosphorization of iron, ± 20 ° C, composition, wt.% C 4; Mp 0.76; SI 0.76; P 0.281.

Mixtures 2 and 3 were obtained by a known method.

From the data of the table it follows that a decrease in the CaO content below 17 wt.% Or an increase in more than 29 wt.% Leads to a significant decrease in the degree of dephosphorization, which makes it necessary to increase the amount of the refining mixture, i.e. makes it low-tech and leads to an increase in the cost of dephosphorization. At the same time, the CaCIa content should remain between 63-78%, and AlaOa within 6-12%. CaCIa content less than 63% due to an increase or above 78%

by reducing CaO, it also leads to a decrease in Av. In addition, at higher levels of CaCIa, the phenomenon of re-phosphorization is observed, which makes use of

mixture ineffective

When using a slag mixture for secondary furnace dephosphorization, such as cast iron, the expected economic effect consists of reducing the cost of charge materials, reducing the time of dephosphorization in the converter and increasing its productivity.

Claims (2)

1. Refining slag mix for dephosphorization of metal melts containing oxide and calcium chloride, characterized in that, in order to reduce the cost of the mixture and reduce the occurrence of dephosphorization, it additionally contains aluminum in the following ratio, wt.%: CaO17-29 CaClz63-77 A 206-6-12. 2. The method of obtaining refining the slag mixture for the dephosphorization of BOB metals, including loading lime and calcium chloride into the kiln, melting and releasing the melt, characterized in that, in order to reduce the cost of the mixture and reduce the occurrence of re-phosphorization, chloride wastes of titanium-magnesium production are additionally introduced into the furnace in the following ratio of calcium chloride, lime and chloride waste of titanium-magnesium production (1.12-4.0): (0.14-0.7): 1.