27681
This system can be used to recover lithium from brine even in the presence of magnesium ions as well as other dissolved cations .
 Chemical: lithium; Chemical: magnesium
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: lithium, magnesium 
Answer:
 Chemical: lithium; Chemical: magnesium