Document Type


Publication Date

Spring 4-21-2023



The removal of arsenic, selenium, and metal species from hydrometallurgical solutions and wastewaters has been and continues to be an important research topic. This presentation includes a discussion of the research conducted at Montana Tech in the Department of Metallurgical and Materials Engineering during the past fifty years. The discussion is focused on removal of arsenic by co-precipitation with Fe(III) and Fe(II), co-precipitation with Fe(III) and Al(III), reduction using elemental iron; the removal of selenium by elemental iron and catalysed iron; and the removal of cadmium, copper, nickel, zinc by co-precipitation with Fe(III) and Al(III).

This presentation is based on the research of Master of Science graduate students, industrial and academic colleagues, at the Montana College of Mineral Science and Technology (which morphed to Montana Tech [1977], then to Montana Tech of The University of Montana [2000], then to Montana Technological University [2019]). The referenced work of each of the graduate students in this presentation is gratefully acknowledged. The following summary does not include other research studies conducted in the Metallurgy/Materials Engineering Department by other teaching and research colleagues (except for some of the work supervised by Dr. Hsin Huang). See Appendix A for a list of the Master of Science research thesis students (11) and their research topics highlighting their contributions to our departments’ research efforts (student theses are readily available, on-line in digital format, at the Montana Tech Library).

The referenced research was supported by the U.S. Environmental Protection Agency Mine Waste Treatment Program (EPA-MWTP), the National Science Foundation, and the Center for Advanced Metallurgical and Mineral Processing (CAMP) over a period of ten years.

Because of our extensive arsenic research, I have included a recent detailed annotated literature survey of the topic “Fixation of Arsenic (August 2021)” prior to presenting a summary of the Twidwell group’s specific research studies and results at Montana Tech. The reader may bypass the literature survey by going to page 32 for a summary of Montana Tech research studies and results.

Included in

Metallurgy Commons