Anandakanda 2.6.26

2.6.26

kṣiptvā cullyāṃ pacedagnau cālayellohacaṭṭunā /
yāvadbhasma tamuddhṛtya bhasmatulyāṃ manaḥśilām //

one should throw it [with the lead] onto a hearth, cook it over fire, and stir it with an iron ladle.
When it turns to ash, one extracts it, [adds] realgar equal to the ash,