Continuous monitoring and adjustment of the lithium content in liquid PbLi alloys: assessment of an electrical resistivity meter in a loop system

The operation of an electrical resistivity meter to detect changes in the lithium content of liquid PbLi alloys has been assessed in a loop system. Initially, the response of the monitor to ingress of oxygen was tested. The reaction of oxygen with flowing PbLi alloys was detected by the apparatus and the decrease in lithium content was found to be in agreement with Li2O formation. Subsequently, the adjustment of the lithium concentration was performed by the addition of LiPb. These compounds were easily prepared by mixing lead and lithium in equimolar proportions from the liquid state. The ingots produced after solidification of the mixture were then immersed in the alloy of the loop and were entirely dissolved within a short period. The resistivity meter responded very well after each LiPb addition and a steady increase in lithium content was observed. The monitor was sensitive to composition changes of ± 0.15% at.% Li. Its responses time was limited only by rate of sampling and mixing in the loop.