DC arc smelting of silicon: Is it technically feasible? - saimm

the dissolved sample occurred before the concentration of various elementsanalysis could be measured (using Atomic Absorption technique, AA). Repeatsample preparation and analysis did not improve the outcome, particularlywhen the metal content in the sample was high. Similar difficulties wereexperienced with other samples containing high levels of silicon.It is believed that oxygen lancing added between 140–150 kg of iron into the metalphase. However, it is difficult to assess iron contamination that was caused by thesampling spoons. Obviously, pick-up of iron by such samples would have the effect ofdecreasing the silicon content. This appears to have been the case where samples takenwith alumina or graphite cups tended to show a lower iron content in general(Table VIII). Although the data is not very conclusive, it provides an indication thatsampling was a problem when steel spoons were used. As a result, silicon contentappeared to be lower, as compared to the samples taken using alumina or graphitespoons. Notice that the alumina crucible gave somewhat higher aluminium contents incertain samples.110Table VI: Chemical analyses of the metal (mass %), and tapped masses per tap (condition)Tap Mass,kg Al Si Ca B Mn Fe C P Total Si *1 (1)2 (1)3(1)4(1) 14.0 2.30 47.50 2.14 0.003 0.20 41.80 0.14 0.06 95.67 53.115(1) 65.5 1.58 36.37 1.22 0.001 0.22 60.33 0.09 0.04 100.34 36.446(1)7(1) 26.1 2.03 46.60 0.57 0.001 0.20 54.00 0.05 0.02 103.92 43.08Average-1 1.97 43.49 1.31 0.001 0.21 52.04 0.09 0.04 99.29 44.218(2) 28.2 2.36 33.80 1.20 0.002 0.15 54.40 0.10 0.01 92.40 41.739(2) 11.7 1.06 43.35 0.24 0.001 0.17 54.48 0.05 0.01 99.69 43.9410(2) 35.4 3.98 18.50 1.43 0.001 0.05 20.00 0.19 0.04 44.53 74.2811(2) 20.6 2.70 25.97 2.01 0.001 0.05 20.00 0.09 0.03 51.18 75.1212(2) 11.3 2.62 50.13 1.86 0.002 0.08 20.47 0.04 75.66 74.8813(2) 32.1 0.71 48.87 0.33 0.001 0.09 20.50 0.06 0.05 70.98 78.2Average-2 2.24 36.77 1.18 0.001 0.10 31.64 0.10 0.03 72.10 64.6714(3) 9.9 0.95 48.90 1.16 0.001 0.10 20.50 0.09 0.04 72.07 77.1115(3) 18.3 0.87 53.90 0.67 0.002 0.01 36.28 0.06 0.04 92.16 62.0216(3) 33.9 0.83 40.23 0.20 0.001 0.18 60.40 0.12 0.02 102.34 38.1917(3)18(3)Dig-outTopDig-outmiddleDig-outbottomDig-outloose7.35.169.78.01.53 66.45 1.27 0.003 0.07 0.85 24.97 0.05 95.51 71.212.18 65.45 2.31 0.007 0.08 2.18 17.94 0.03 90.49 75.223.30 53.30 2.74 0.005 0.10 28.50 9.06 0.04 97.36 56.20.81 37.10 0.24 0.007 0.14 61.20 0.14 0.06 100.07 37.29Average-3 1.51 52.27 1.16 0.001 0.10 32.18 6.58 0.06 93.92 58.36Overall 1.85 45.25 1.19 0.001 0.12 35.49 3.34 0.04 87.34 57.91* by difference: %Si = 100-∑Analysis of other elements. Average = weighted average