Application Technology Development Of Limonite In Sintering Of Baogang

Based on the area of limonite and limonite in Australia as the research object,in the normal temperature based on the study of the physical and chemical properties and the sintering performance and industrial tests have been carried out respectively,and the alternative serpentine,and other types of limonite technical indexes of sintering production process to make a comparison,to determine the various application effect of limonite sintering production at baotou steel,To provide theoretical guidance and technical support for reducing the raw material cost of iron making.Serpentine is replaced by limonite after separation to adjust the content of Si O₂ in sinter.When the selected limonite is added with 10.2%,the sintering blending cost can be reduced by26.89 yuan/t compared with the base point,and the sinter grade(theoretical calculation)can be increased by 0.03%.However,the sinter quality and process indexes are significantly worse.The drum is reduced by 1.87%,the fuel consumption is increased by 1.06 kg/t,and the Zn content of sinter is increased by 0.093 kg/t.The industrial application results show that when the proportion of Australian ore is increased by 4%in the ratio of iron-containing raw materials,and 2%steel slag and 1.6%in-zone limonite are substituted for 6%FMG powder and 1.5%serpentine,the sintering process parameters and chemical composition of sinter have little change.The drum strength decreased by 0.05%and the average particle size decreased by 0.21mm.The decrease of utilization coefficient is not obvious.After the replacement of serpentine,the content of harmful elements in sinter increases by 0.012%.The uneven porosity in the macrostructure of sinter and the decrease of impact resistance result in the increase of the number of high ore returns by 2.96%.When the ratio of Pb powder decreased from 32%to 22%,and the ratio of Gibson powder increased by 8.4%from 0,the sinter yield decreased from 69.19%to 68.27%,with a slight decrease.The utilization coefficient decreased from 1.45 t/m²·h to 1.41 t/m²·h.Solid fuel consumption increased from 70.28 kg/t to 71.09 kg/t;The vertical sintering velocity decreased from 20.98 mm/min to 20.64 mm/min.The drum strength showed a decreasing trend from67.07%to 66.13%.Due to the fine particle size of Gibson high-silica-brownite,the water distribution increased from 6.50%to 6.90%after sintering in order to ensure the stable vertical velocity of sintering.There was no significant change in sinter yield when 6%and 12%FMG western powder was used to partially replace wool tower powder.The sinter yield decreased from 69.19%to68.27%when 18%FMG western powder was used to replace the wool tower powder.The utilization coefficient decreased obviously from 1.19 t/m²·h to 1.002 t/m²·h.The industrial production practice showed that the granulation efficiency was increased by 6.07%after adding water.The opening of ignition bellows and tail bellows is within a reasonable range,adjust the feeder,increase the thickness of the material layer by 20 mm,and increase the rat io of quicklime by 0.8%.The ratio of PB powder in iron-bearing raw materials of sinter was decreased,and the ratio of super powder was increased from 0 to 22%.When the ratio of super powder was less than 10%,the change of sintering yield,utilization coefficient and sinter drum strength was not obvious.When the ratio of super super powder is 22%,the sinter drum strength decreases from 66.40%to 65.87%.When 10%super powder is added,the total flux consumption per unit can be reduced by 0.59kg/t.The industrial production practice shows that the sinter quality index has no obvious change after the addition of 5%super special powder instead of WPF powder,but it is beneficial to reduce the ore blending cost.After adding 5%super iron ore powder,the negative pressure of sintering decreases by 1 k Pa,and the air permeability of the feed layer is obviously improved.In order to maintain a reasonable vertical velocity of the feed layer,the technical measures of increasing the thickness of the feed layer to 720 mm and reducing the moisture value by 0.2%are adopted to ensure the quality and output of the sinter.