Certain features of the extraction of vanadium in blast furnaces at the Chusovoi metallurgical plant

Abstract

Aspects of the reduction of vanadium in blast fumaces and its transfer to the pig iron have been studied quite extensively by V. V. Mikhailov, P. G. Shtengel'meier, S. V. Shavrin, A. F. Chentsov, and others [1][2][3][4][5] 9]. They determined that the amount of vanadium transferred to the pig iron depends on the basicity and volume of the slag, the temperature of the pig, and other factors. These conclusions were based on the results of laboratory studies or averaged indices of trial heats conducted over a relatively long period of time. However, the averaging of the indices resulted in some "smoothing" of isolated anomalies in the data.We refined the initial relations on the basis of data from chemical analyses (more than 1000 taps on each blast furnace at the Chusovoi Metallurgical Plant). The method used to analyze data on the taps involved grouping them on the basis of various factors and determining the average index for the taps in the different groups. We then used the program Microsoft Excel to determine the relations and constructed regression curves ( Figs. 1 and 2).It was established that the amount of vanadium present in the slag in the form of V205 increases with a decrease in the temperature of the pig iron. If the temperature of the pig increases, then so does the vanadium distribution coefficient L v (Tables 1, 2, 3).It was also determined that in certain taps (V205 > 0.6) the dependence of the Si and V contents of the pig iron on the content of C205 in the slag did not conform to the general law that was established. For example, when the concentrations of these elements in the pig iron was sufficiently high, the V205 content of the slag in the corresponding heats was significantly higher than in the other groups of taps.In several of the trial heats, it was observed that vanadium could undergo sublimation in the high-temperature zones of the blast furnace [1, 8]. It can be suggested that some of the vanadium sublimes and accumulates in the form of a slag crust near the bosh. The crust begins to slide down the furnace after it has reached a certain critical mass. This is accompanied by a sudden increase in the W203 content of the slag, while the vanadium content of the pig remains nearly unchanged. The process just described is more pronounced on a small blast furnace (such as blast furnace No. 1), which may be due to the composition of the slag, the more intensive operation of the furnace, or features of its profile. This matter requires further study. When the crust slid down the furnace, the concentration of vanadium in the hearths of furnaces Nos. 1 and 2 increased by t8.2% and 19.3%, respectively. Figure 3 shows the dependence of the total mass of vanadium in the pig iron and slag on the mass of vanadium in the slag.It should be mentioned that an increase in the V203 content of the slag is accompanied by an increase in the silicon content of the pig iron, i.e., by an increase in temperature in the hearth. The rise in temperature also results in sliding of the slag crust.Analysis of the data ...

A Study of Some Elemental Distributions Between Slag and Hot Metal During Tapping of the Blast Furnace

“…Another way of studying equilibrium among slag-metalgas reactions is to calculate distribution coefficients from actual production data. Data on calculated distribution coefficients of silicon (LSi = 15-50) [3,4], sulphur (L s = 10-90) [3,[5][6][7][8], manganese (L Mn = 0.3-1.8) [3,[7][8][9] and vanadium (Lv = 1-9) [10] from various blast furnaces can be found in the literature. The investigation covered in this report employed production data from a commercial blast furnace at SSAB Oxelosund AB in Sweden.…”