| The separation of titanium from the slag of blast furnace in PanZhiHua was studied experimentally and theoretically in this paper and the process of the slag's comprehensive exploitation was developed. By adding NaOH into the slag, the titanium white powder, the 4 A molecular formula and the residue, which could be used as the additive of cement, would be obtained. The recycle and the comprehensive exploitation of the slag became possible.The slag of blast furnace in PanZhiHua contains titanium, aluminum and silicon oxides, which are made up more than 60% of the slag. These oxides will react with NaOH at high temperature, then the first separation of the slag can be immediately realized thanks to the high dissolvability of sodium salts.The route of comprehensive exploitation of the slag was designed on the basis of its property, the mechanism, the thermodynamics and the dynamics of its separation.Through discussing the adding manner of NaOH, the temperature, the thermodynamics and dynamics of the eutectic slag, the eutectic conditions at high temperature were optimized.By studying the dip-dying in water and separating including the temperature and the basicity of the dip-dying liquor, the time of dip-dying, the churning up and the dynamics of dip-dying, the optimal conditions of dip-dying were found.Through washing, bleaching, calcining and grinding of the metatitanates, the titanium white powder could be obtained with metatitanic acid.After adjusting the component of mother liquor, aging, grain coarsening, filtrating and drying, the molecular formula could be obtained from the compounds containing aluminum and silicon.The main problems resolved in this paper are as follows: (1) NaOH, used as dissociative reagent, reacts at high temperature with oxides of titanium, aluminum and silicon having high additive value to obtain oxy-salts, which can be easily separated; (2) Adding 66 grams NaOH per 100 grams slag at room temperature, reacting at 1250 and lasting 30 minutes are most favored. The converting efficiency can be expressed by(3) When the churching speed is 2000r/min and the dip-dye time is 80 minutes, temperature has little effect on dip-dye in water. When the resistance of masstransferring is eliminated, the dynamics of dip-dye can be expressed byl-(l-x)1/3 = 0.1259 + 0.01036t,l-(l-x)1/3 =0.2059 + 0.008857t1 -(1-x)1/3= 0.3520 + 0.004072t . The relationship of reacting time and dip-dyeefficiency can be expressed by (4) Crystallizing for 3hours at 35, washed with 10% H2SO4, adding K2SO4) then calcined at 650 for 1 hour, the titanium white could be produced; (5) When the ratio of SiO2 to Al2O3 is 2, after aging at 50 for 2 hours and grain coarsening at 95 for 3 hours, the 4A molecular formula whose exchanging capacity of calcium ion is more man 270 mg/g, which is close to the 4A molecular formula in scour industry.Compared with the other studies, this paper is prominent due to using NaOH as dissociative reagent to achieve titanium white powder. This makes it possible to make good use of the blast furnace slag in PanZhiHua without industrial pollution. |
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