| Most of the charge structure of blast furnace iron making in China is based on sinter with high basicity.Therefore,the quality of sinter has an important influence on blast furnace production and is largely limited by the iron ore raw materials used in the sintering process.Iron and steel is the largest manufacturing industry in China.Due to market competition and the expansion of steel production scale,various iron and steel enterprises adopt various means to reduce pig iron cost,among which reducing sinter blending cost is one of the preferred measures.It is an inevitable development trend to replace high-priced ore with low-priced ore.Since the price of limonite is lower than that of hematite,increasing the use of limonite with lower cost gradually in iron and steel enterprises without affecting the quality of sinter is the main idea for major steel mills to reduce the cost of sinter blending.At present,Baotou Steel adopts "4321" sinter blending idea,which includes baiyun Obo self-produced concentrate 4,imported ore 3,ore 2 in the zone and Mongolia mine 1.Due to the difficulties in the procurement of mines in the area and Mongolian mines,the amount of imported ore is gradually increasing,while with the continuous rise of Platts index,the price of imported ore is higher,making the sintering cost higher.In this paper,it is proposed to replace Yangdi powder with FMG mixed powder and Australian powder with Maota powder to reduce the ore blending cost.FMG mixed powder and Yundi powder are both limonite with similar properties.In terms of price,FMG mixed powder is cheaper than Yundi powder.Due to its high Si O2 content and slightly lower price than Australian powder,Maolta powder has been used as a Si compounding agent in actual production.The purpose of partially replacing Australian powder with Maolta powder is to study whether increasing the amount of Maolta powder can reduce ore compounding cost on the basis of maintaining original metal lurgical properties.The metallurgical properties of sinter with different ratio were studied by sinter cup experiment.At the same time,combined with the current market situation,ore price of each ore blending scheme is calculated by ore Platts index price,and finally,metallurgical performance score and price are used for calculation,so as to find the ore blending scheme with high cost performance.Through experiments,it can be seen that the reduction of sinter is improved after FMG mixed powder replaces Yundi powder.There was no change in the low tempe rature reduction degradation index.The melting range of refractoriness is narrower than that of yundi ore.After the part of wool tower powder is replaced by Australian powder,the soft melting range of sinter is greatly narrowed,the economic performance is greatly improved,and the cost of sinter blending is correspondingly reduced.Therefore,it can be determined that on the premise of ensuring the quality index of sinter and the stability of high temperature metallurgical property index,FMG mixed powder can replace Yangdi powder in sintering production,and maota powder partially replaces Australian powder,which can effectively reduce the cost of sinter and bring more considerable economic benefits to enterprises. |
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