Ionic Liquid‐Mediated Extraction of Keratin From Tannery Mixed Hair Waste

In this work, keratin was extracted from tannery mixed hair waste using the ionic liquid (IL) 1‐butyl‐3‐methylimidazolium chloride ([BMIM]Cl). The process was optimized by varying the sheep:goat hair mass ratio and the hair:IL mass ratio at 130°C for 10 h. The complementary structural features of mixed hair appeared to enhance dissolution, yielding ∼80% keratin under optimized conditions of a 1:1 sheep:goat ratio and 1:40 hair:IL ratio. ATR‐FTIR, solid‐state 1 3 C NMR, XRD, DSC, and TGA suggested that the extracted keratin largely retained its native structure. The IL was recovered at up to 98% and reused with no apparent loss of extraction efficiency. The results indicate that IL‐mediated extraction of keratin from mixed hair waste can provide an efficient, recyclable route that supports waste reduction and value‐added product development in the tanning industry, contributing to a more circular approach to tannery hair valorization.