Activities of mining and metallurgical industry enterprises of the Republic of Kazakhstan: environmental problems and possible solutionsТurgai Alimbaev, Zhanna Mazhitova, Chinara Beksultanova and Nazira TentigulKyzyE3S Web Conf., 175 (2020) 14019DOI: https://doi.org/10.1051/e3sconf/202017514019