Pellet production method based on prediction of compressive strength of pellets in rotary kiln

Abstract

The invention discloses a pellet production method based on prediction of compressive strength of pellets in a rotary kiln. The method comprises the following steps: 1) collecting related operation parameters of the rotary kiln; 2) establishing a motion model of the pellets in the rotary kiln; 3) measuring and calculating average residence time T of the pellets in the rotary kiln; 4) measuring flame length FL and the distribution of burning rate Rfuel of fuel in the flame length; 5) measuring the distribution of temperature of the pellets Tp along the kiln length direction z in the rotary kiln; 6) measuring a predicted value of the strength of the pellets; and 7) performing online control on process parameters of the rotary kiln according to the predicted value Qp of the compressive strength of the pellets. By using the method for online prediction of the thermal engineering state and the strength of the pellets in the rotary kiln, the transparency of the production process is increased, the control difficulty caused by information hysteresis is reduced, the risks of low finished product rate, accretion of the rotary kiln and the like caused by insufficient strength of the pellets can be reduced, and the thermal engineering operation of the rotary kiln is optimized in an online manner; and the energy consumption can be reduced and the production benefits can be improved.

Description

technical field [0001] The invention relates to the field of iron and steel metallurgy, in particular to a pellet production method based on predicting the compressive strength of pellets in a rotary kiln. Background technique [0002] my country's iron and steel industry continues to develop. In 2013, the country's crude steel output reached 782 million tons, accounting for 48.66% of the world's output, ranking first in the world for 18 consecutive years. Blast furnace ironmaking-converter steelmaking is still the main process of steel production at present, and the blast furnace charge in my country is mainly high-alkalinity sinter mixed with acid pellets. With the growth of steel production and the increase in the proportion of pellets used in blast furnaces, my country's pellet production continued to rise, reaching 131 million tons in 2013, accounting for 32.25% of the world's total. At present, the pellet production process is divided into shaft furnace, belt roaster ...

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Problems solved by technology

However, this model is only used to predict the wear resistance index of pellets, and does not predict the compressive strength, while the commonly used pellet quality index in my country is compressive strength; on the other hand, there are material movement, Complex phenomena such as fuel combustion (Gorog, J.P., Adams, T.N., Bricombe, J.K. Heat transfer from flames in a rotary kiln [J]. Metallurgical Transactions B, 1983, 43, 411-424. and (Xiao, X.G, Li, J.X., Cao ,T.Y.,Xiao Z.Q.Mathematical model for the rotary kiln process and its application[J].Chinese Journal of Metal Science and Technology,1991,7,55-64.), the calculation of the temperature-time curve is different from that of the belt roaster However, there is no relevant report on the application of this model to the prediction of pellet strength in the rotary kiln.

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