The Department of Chemical Engineering USU, in collaboration with the Chemical Engineering Alumni Association of USU, organized a guest lecture on Saturday, March 6, 2021. This online guest lecture was attended by students, lecturers, and several alumni of the Chemical Engineering Department at Universitas Sumatera Utara. The keynote speaker for this lecture was Darwin Saleh Siregar, S.T., M.Si., an alumnus of USU's Chemical Engineering Department who currently serves as the Technical and Project Director at PT Borneo Alumina Indonesia. The event began with an opening by the MC, a prayer, and welcoming remarks by the Head of the Chemical Engineering Department, Ir. Maya Sarah, S.T., M.T., Ph.D., IPM.

Darwin Saleh Siregar, S.T., M.Si., delivered the lecture on the topic “Mineral Processing Bauxite to Alumina.” He explained the global alumina industry, Indonesia’s natural resource potential for producing alumina from bauxite, processes, operational conditions, production flows, waste handling from the alumina production process, and alumina’s derivative products. The transformation of bauxite into alumina, which is later processed into aluminum, involves several stages: bauxite mining, washing/separating bauxite from impurities like clay, particle size separation, followed by the Bayer process involving calcination to produce alumina. Alumina is then subjected to electrolysis at high temperatures to form aluminum.

During the lecture, the speaker provided an opportunity for participants to engage in a Q&A session after each subtopic. Several participants enthusiastically asked questions, which were directly answered by the speaker. Although this lecture was held online, it is hoped that the knowledge shared will be valuable to all participants.