钢液RH精炼中喷粉脱硫的动力学

考察和分析了钢液RH喷粉脱硫过程及机理，探讨了该过程的速率.基于双重阻力传质理论和体系内的质量衡算，建立了RH喷粉脱硫动力学模型，确定了模型各有关参数，包括各传质系数和钢液内参与脱硫反应的粉量等.以该模型对300tRH装置内设定的不同初始硫含量和喷粉量下喷吹石灰基粉剂脱硫作了计算和模拟，相应的钢液环流量和喷粉速率分别取为100t／min和150kg／min；设定的初始硫含量（质量分数，10－4％）和喷粉量分别为70，60，50，40，30；20和10，8，6，5，4，3kg／t—steel对每种工况计算了8个循环，整个脱硫处理时间为24min．结果表明，由该模型所作的估计与一些工业性数据相当吻合；在（60—80）×10-4％的初始硫含量下，喷吹3—5kg／t—steel石灰基粉剂（85％CaO＋15％CaF2）,总处理时间12—20min，有可能使钢液硫含量达到（5—10）×10－4％以下水平；强化喷粉操作。

Effect of polycarboxylate-type superplasticizer on the paste fluidity based on the water film thickness of flocs

The excess water film theory and the properties of flocs are integrated to examine the effect of the polycarboxylate-type superplasticizer on the paste fluidity. The theory states that excess water can surround the flocs rather than the particles and that the cell consists of a floc and a superficial water film. Experiments on limestone powder pastes were conducted to verify the theory. The superplasticizer dosage （sp%） and the water-powder ratio by volume （Vw/Vv） were systematically varied. A sedimentation balance method was used to measure the size distribution of the flocs in the limestone powder pastes. The water film thickness （WFT） of flocs was then calculated and shown to determine the paste fluidity. Based on this WFT of flocs, the effect of the sp on the paste fluidity was determined and then compared with the effect of water.