The rules in the Department of Chemical Engineering for technical electives are posted on the web on the undergraduate advising page. The rules are updated from time to time and students are advised to choose the list that corresponds to their catalog year (usually the year they entered Michigan Tech).
As of 3 February 2015, the following courses count as chemical engineering elective:
CM 2200 Intro Minerals and Materials* 3cr
CM 3450 Computer-Aided Problem Solving* 3cr
CM 3820 Sampling Statistics and Instrumentation* 3cr