Although single-crystal black phosphorus (BP) can be prepared by the mineralization method, there have been few reports on the growth process of BP under non-vapor transport conditions. In this paper, a simple synthetic approach based on Sn-I-assisted mineralization is developed to produce high-quality orthorhombic single-crystal BP in a quartz tube. Through different temperature variations, we study the growth process of single-crystal BP under non-vapor transport conditions. The results show that by using the appropriate conditions, the mineralization method can be used to produce high-quality orthorhombic single-crystal BP. During the cooling process from 620 ℃ to 500 ℃, Hittorf’s phosphorus is formed. It is shown that 500 ℃ is a critical temperature for BP growth, which properly prolongs the holding time, promoting the growth of single-crystal BP. Finally, the growth process of BP under non-vapor transport conditions is clarified.