TECHNOLOGY OF HIGH TEMPERATURE ATMOSPHERE ADJUSTMENT AND MAGNETIZATION ROASTING OF ROTARY KILN
Magnetization roasting is a process that transforms weakly magnetic iron minerals such as limonite,siderite,and sedimentary hematite into strong magnetic iron minerals under certain temperature and atmosphere conditions,and then separates the iron containing materials from the gangue through weak magnetic separation technology.The rotary kiln is a traditional magnetization roasting instrument for iron ore,which generally uses the addition of 0～15 mm iron ore and reducing coal from the feeding end.However,there are problems such as low production capacity,high energy consumption,poor roasting ore quality,and"agglomeration"inside the kiln.Therefore,a difficult to select iron ore full particle size high-temperature atmosphere regulation magnetization roasting process is proposed.This process involves first drying,preheating,and pre reduction of 5～15 mm coarse particles ore in the kiln to improve the dynamic conditions of the reduction magnetization process of coarse ore particles;At room temperature,fine-grained ore with a particle size of 0～5 mm and high volatile coal are synchronized in batches and then fed into the kiln.By adjusting the high-temperature reduction atmosphere,the concentration of the reduction atmosphere in the material layer is controlled to maintain a relatively low level,ensuring uniform reduction between the surface and core of coarse particles,as well as between coarse and fine particles,and stabilizing the generation of Fe3O4.Under the process conditions of roasting temperature of 950 ℃,reduction time of 30 minutes,reducing agent ratio of 1.8％,and reducing agent particle size of 5～10 mm,the magnetization roasting effect of 0～15 mm Jingtie Mountain powder ore is the best;In the stable roasting experiment,the roasting ore adopts a two-stage grinding and three-stage magnetic separation process,which can obtain magnetic separation indicators of concentrate TFe grade 58.26％and metal recovery rate 90.29％.
magnetization roastingfull particle sizerestore the atmospheremetal recovery rate
万方数据
维普
