| In recent years, imported iron ore price has been at a high level and the domestic steel production capacity surplus. Iron and steel industry continued in a low profit or loss of status in China. China is rich in high-phosphorus iron ore resources. It will greatly reduce the cost of raw material of iron and enterprises if the ore can obtain effective development and utilization. Adding dephosphorization agent in sintering process can change the phosphorus element into stable gas containing phosphorus, which can achieve the purpose of gasification dephosphorization.The ore of Fe2O3 45.74% and P 1.37%, natural alkalinity 0.36, belongs to oxide ore of low sulfur high phosphorus. Fluorapatite and hematite present oolitic structure of alternating symbiotic and mutual inclusion. Oolitic particle size is 200~550μm and disseminating closely. The ore crushing into 100 mesh below can destroy the oolitic structure, which is conductive to the dephosphorization reaction.C and Ca5(PO4)3F need high temperature to react in sintering process; Adding SiO2 can reduce the temperature, but the product is phosphorus steam(P2) that can easily be oxidized to produce solid; adding C、SiO2 and CaCl2 can not only make the reaction temperature below 810℃, but also the dephosphorization product turns into stable PCl3 gas. And the dephosphorization rate is about 20%. The optimal experimental conditions:C4%、SiO21.41%、CaCl21.36%、R=1.2.A kinetic study on the dephosphorization carried out by integrated thermal analyzer.There are two obvious weight loss, and gasification dephosphorization reaction occurs in second stage. The weight loss curve shifts to high temperature region with the increase of heating rate, and there is a sharp endothermic peak in dephosphorization stage; the reaction activation energy is 250.55kJ·mol-1, so overcoming higher energy barrier in order to make the reaction occur; the gasification dephosphorization reaction mechanism function meets the two-dimensional diffusion Valensi equation. |
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