The phase of mitosis which is associated with the formation of the nuclear envelope

The phase of mitosis that is associated with the formation of the nuclear envelope is telophase. 

During telophase, several key events occur, including the reformation of the nuclear envelope around the separated sets of chromosomes. This process involves the reassembly of the nuclear membrane and the integration of nuclear membrane components to enclose the chromosomes within each daughter nucleus.

Additionally, telophase is characterized by the decondensation of chromosomes, which revert back to their extended, interphase state, and the reappearance of nucleoli, which are regions within the nucleus where ribosomal RNA synthesis occurs.

Overall, telophase marks the conclusion of chromosome segregation and the beginning of nuclear reorganization as the cell prepares to enter interphase. The reformation of the nuclear envelope ensures the proper compartmentalization of genetic material within the newly formed daughter cells.