The term independent of \( x \) in the expansion of \( (2x^2 - \frac{1}{x})^9 \) is:

General term \( T_{r+1} = {^9\text{C}_r} (2x^2)^{9-r} (-x^{-1})^r = {^9\text{C}_r} 2^{9-r} (-1)^r x^{18-3r} \). Setting \( 18 - 3r = 0 \implies r = 6 \). Thus \( T_7 = {^9\text{C}_6} 2^3 (-1)^6 = 84 \times 8 \times 1 = 672 \).