| 摘要 |
PURPOSE:To efficiently reduce the oxide of chromium and iron in chromium ore at a low cost by lowering pellets consisting of pulverized powder of the chromium ore and carbonaceous reducing agent in a vertical type reaction pipe consisting of a preheating chamber, combustion chamber and cooling chamber. CONSTITUTION:Powdery coke and anthracite as reducing agents are mixed with the powdery Cr or in the amt. larger than the theoretically required amt. The mixture is pelletized to pellets having about 10mm diameter by a binder such as bentonite. The pellets 8 are charged into the vertical reaction furnace 3 consisting of a preheating zone 3a, reducing zone 3b and cooling zone 3c from the upper part thereof. The pellets 8, preheated by the high-temp. reactive exhaust gas rising from below, fall into the reducing zone 3b and are indirectly heated to 1,200-1,500 deg.C in the combustion chamber 1 having a burner 2 which uses gaseous or liquid fuel. After the Cr ore is reduced at high reducibility, the Cr ore is taken out of the furnace 3 through the cooling zone 3c. The Cr ore is subjected to the solid phase reduction at the low cost by using the inexpensive fuel without using the costly electric power as a heat source for reduction.
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