Agris Setiawan Universitas Pembangunan Nasional "Veteran" Yogyakarta Indonesia
Fransisca Diana Wahyuningsih Department of Metallurgical Engineering, Faculty of Mineral Technology, Universitas Pembangunan Nasional Veteran Yogyakarta, Yogyakarta, Indonesia, 55281 Indonesia
Riria Zendy Mirahati Department of Metallurgical Engineering, Faculty of Mineral Technology, Universitas Pembangunan Nasional Veteran Yogyakarta, Yogyakarta, Indonesia, 55281 Indonesia