Experimental Study Of Operating Parameters Of Lime Slaking Process And Dissolution Rate Of Calcium Hydroxide

The study of this paper is one part of 863 Nation Plan of China under project 2001AA642030-1, whose name is "medium and large scale coal burning boiler dual-alkali FGD technology and equipment industrialization". It mainly studied lime slaking process and Ca(OH)2 dissolution rate in regenerated reactor. Through studying and optimizing lime slaking process, it analyzed the mechanism of lime slaking reaction and found the optimum operating conditions to increase the activity of lime milk. In order to increase utilization rate of lime and desulfurization rate, it also studied the influence of operating conditions on the dissolution rate of Ca(OH)2.In the study of lime slaking process, it mainly studied the influence of operating parameters including agitation intensity, particle diameter, water temperature, H2O/CaO ratio and some common ions(Cl-, F-, SO42- and SO32-) etc. The experimental result can be applied to industrial lime slaker as a reference. And it discussed the feasibility of recycling wastewater and process water in WFGD as lime slaking water.Simulating the operating conditions in regenerated reactor of the dual-alkali FGD, the dissolution rate of Ca(OH)2 had been studied by using pH-stat method and rotating disc system. It studied the changing rule of dissolution rate of Ca(OH)2 at different operating conditions including rotating rate(100~2000rpm), pH(4.0-7.0) and temperature(25~55 C). According to the effect of operating conditions on the dissolution rate, the most important parameter was found. Optimizing the operating conditions will increase the utilization rate of lime and reduce desulfurization cost of dual-alkali FGD.