We analyze the dust properties of 57 870 \(\mu\)m selected dusty star-forming galaxies in the GOODS-S using new deep ALMA 1.2 mm, 2 mm, and 3 mm continuum imaging together with other far-infrared through millimeter data. We fit the spectral energy distributions (SEDs) with optically thin modified blackbodies to constrain the emissivity indices and effective dust temperatures, finding a median emissivity index of \(\beta = 1.78^{+0.43}_{-0.25}\) and a median temperature of \(T_d = 33.6^{+12.1}_{-5.4}\) K. We observe a negative correlation between \(\beta\) and \(T_d\). By testing several SED models, we determine that the derived emissivity indices can be influenced by opacity assumptions. Our temperature measurements are consistent with no evolution in dust temperature with redshift.