On the Estimation of Commercial Values of Iron Ores
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The commercial values of iron ores as the raw. materials for the production of low phosphorus pig iron by means of electric furnaces were estimated by the present writer from the metallurgical point of view. According to the custom in this country, hematite ore composed of 50%Fe, A% SiO_2, B% Al_2O_3, a% CaO, b% MgO, <0.3%S, and 0.02% P is taken as a standard iron ore. When the composition of commercial ore differs from that of the standard one, the smelters usually revise the price of commercial ore by their customary rules. To make this revision of price more scientific, the present investigation was undertaken. To make the matter simpler, some assumptions were made as follows : (1) The ore is assumed to be smelted alone without mixing with any other ore, except manganesian ore. (2) The basicity of slag{%(CaO+MgO)/%SiO_2} is kept at 1.3. (3) The content of FeO in slag is limited to 3.0. (4) 4% SiO_2 in the ore will be reduced to Si and dissolved into the pig iron produced. Then the commercial price of iron ores should be revised with regard to the content of iron, manganese, phosphorus and sulphur in the ores : (1) A premiun or a reduction of 0.002F{10±(0.33+0.018A-0.013B)} ±(8.5+0.45A-0.35B)E±(1.41A-1.09B)D ±(14.63+0.78A-0.68) W±0.01 (L+P+t)±0.05e yen per ton of ore should be paid for each percent of iron on or off from 50. (2.) If the ore contains manganese, a premium of 0.033F_<mn>+0.002F(0.33+0.018A-0.013B)+(1.41A-1.09B)D+(8.5+0.45A-0.35B)E+(14.63+0.78A-0.6B) W+0.01(L+P+t)+0.05e yen per ton of ore should be paid for each percent of manganese. (3) If phosphorus content in the ore is below 0.02%, a premium of 0.016F (0.33+0.018A-0.013B)+(11.28A-8.72B)D+(68.0+3.60A-2.80B)E+(117.04+6.24A-4.8B) W+0.08(L+P+t)+0.40e yen per ton of ore should be paid for each 0.005% below 0.02%. (4) When the sulphur content in the ore is above 0.3%, up to 3.5% the maximum allowed, 500 yen or more per ton of ore should be deducted. (5) If the ore is magnetite or limonite, it requires 150 or 120 kWH respectively more than hematite to produce one ton of pig iron. Hence, the extra pay for electric power per ton of magnetite or limonite must be deducted from the price of corresponding hematite ores. In these revision formulas, A is the silica content in percent in the ore, B the sum of CaO and MgO content in percent in the ore, D the price of 1 ton of limestone, e the cost of one kilogram of electrode, E the price of 1 kWH of electric power, F the price of one ton of standard iron ore. F_<mn> the price of one ton of 30% manganese ore. L the labour cost per ton of pig iron produced. P the repair cost per ton of pig iron. t the interest per ton of pig iron produced, and W the cost of water granulation of slag per ton of pig iron produced.
- 東北大学の論文
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関連論文
- Fundamental Researches on Metallurgical Treatment of Manganese Ores. I : On the Equilibrium in the Reduction of Mn_3O_4 with CO.
- On the Estimation of Commercial Values of Iron Ores
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