4 Raw Materials,Fluxes,Fuels and Their Preparation
4.1 Entry Requirements of Raw Materials,Fluxes and Fuels
4.1.1 The entry of raw materials into the sintering plant shall meet the following requirements:
1 The particle size of iron-bearing raw materials shall be 0-8mm,the particle size of mill scale shall be less than 8mm,and that of steel slag shall be less than 5mm.The particle size of special iron ore fines and iron ore concentrates shall be determined according to the test results.
2 The iron-bearing raw materials shall be blended homogenously.For blended ores,the allowable deviation of the TFe grade fluctuation should be±0.5% and that of the SiO2 should be±0.2%.
3 The moisture of magnetite concentrate shall be less than 10%,and that of the hematite concentrate shall be less than 11%.
4.1.2 The entry of flux into the sintering plant should meet the following requirements:
1 Lime stone:particle size should be 0-80mm,the content of CaO should not be less than 52%,the content of SiO2should not be more than 2.2%,and moisture should be less than 3%.
2 Burnt lime:particle size should be less than or equal to 3 mm,the proportion of CaO should be greater than or equal to 85%.
3 Slaked lime:particle size should be less than or equal to 3 mm,the proportion of CaO should be greater than or equal to 60%,and moisture should be 18%-20%.
4 Dolomite:particle size should be 0-80mm,moisture should be less than 4%,the proportion of MgO should be greater than or equal to 19%,the proportion of SiO2should be less than or equal to 3%.
5 Serpentine:particle size should be 0-40mm,the moisture should be less than 5%,the proportion of CaO+MgO should be greater than 35%.
6 Lightly calcined dolomite fines:particle size should be 0-3mm,the proportion of CaO should be greater than or equal to 52%,the proportion of MgO should be greater than or equal to 32%,the proportion of SiO2should be less than or equal to 3.5%.
7 Magnesite:particle size should be 0-80mm,the moisture should be less than 4%,the proportion of MgO should be greater than or equal to 19%,the proportion of SiO2should be less than or equal to 3%.
4.1.3 The entry of fuels into the sintering plant shall meet the following requirements:
1 Coke breeze:particle size should be 0-25mm,the proportion of fixed carbon should be greater than or equal to 80%,and moisture should be less than 12%.
2 Anthracite:particle size should be 0-40mm,moisture should be less than 10%,the ash content should be less than 15%,the volatile content should be less than 5%,the content of S should be less than 1%,and the proportion of fixed carbon should be greater than 75%.
3 The fuels such as coke oven gas,natural gas,converter gas,BF gas or other gas fuel should be adopted for sintering ignition.When using coke oven gas,natural gas,converter gas and mixed gas as the ignition fuel,the gas pressure in the vicinity of sintering cooling room shall not be less than 4000Pa,and when using the BF gas as the ignition fuel,the gas pressure in the vicinity of sintering cooling room shall not be less than 7000Pa.The dust content of all kinds of gases should be less than 10mg/m3.