The method of smelting nickel iron in a DC submerged arc furnace is not complicated. After the ore is dried and fluidized bed roasted, the calcined sand with a temperature of 800-850 ℃ is added to the DC ore furnace and melted at a furnace temperature of 1650 ℃. The resulting liquid nickel iron can be directly produced into stainless steel or refined and cast into ingots before being put on the market for sale.
Compared with conventional AC submerged arc furnaces, DC submerged arc furnaces have the following main advantages.
1. Fine grained ore can be directly utilized. Conventional AC ore heating furnaces cannot directly process fine-grained ores, and they need to be pelletized to improve yield and maintain the permeability of the furnace charge. The DC ore furnace can directly process fine-grained ore without the need for ball making. This is important and particularly attractive for handling fragile and low-grade ores. Some ores, such as laterite nickel ore, contain a large proportion of fine-grained ores, which will also be produced in large quantities during mining, crushing, and grinding processes. If these raw materials can be directly processed, it can significantly reduce costs. The reason why DC arc furnace can directly process fine-grained ore is because DC plasma arc can push fine-grained materials into the molten pool, reducing dust loss.
2. High temperature direct current plasma arc can effectively transfer energy to the molten pool of the furnace, causing rapid reaction and good mixing of materials in the molten pool, thereby achieving uniform temperature distribution and improving yield.
3. The DC ore heating furnace is easy to seal, keeping carbon monoxide inside the furnace, preventing air from entering, and ensuring strong reduction conditions inside the furnace.
4. The DC ore furnace can maintain ultra-high operating temperature.
5. The power supply characteristics and furnace structure of DC and AC submerged arc furnaces are similar, so changing the latter to the former is relatively simple.
6. Conventional AC submerged arc furnaces can generate alloys with a wider range of compositions.
7. The top of the DC ore heat furnace is easy to seal and recover the original and combustion energy of carbon monoxide tail gas, which is used for preheating raw materials to save electricity and reduce production costs. direct current
It is precisely because of the above advantages that the DC submerged arc furnace technology has been successfully promoted and applied to the smelting of ferrochrome, ilmenite, cobalt slag recovery, and zinc slag recovery.
