We report two-dimensional phase-field simulations of locally conserved coarsening dynamics of random fractal clusters with fractal dimension D=1.5 and 1.5. The correlation function, cluster perimeter, and solute mass are measured as functions of time. Analyzing the correlation function dynamics, we identify two different time-dependent length scales that exhibit power laws in time. The exponents of these power laws do not show any dependence on D; one of them is apparently the "classical" exponent 1/3. The solute mass versus time exhibits dynamic scaling with a D-dependent exponent, in agreement with a simple scaling theory.