Prospect of sodium lignosulfonate derived from hardwood black liquor as ingredient in mortar

Abstract

Lignosulfonate, derived from grasses and softwood lignins, are able to increase workability of concrete mixture. Based on the availability of hardwood as raw material III pulp and paper industry in Indonesia, the black liquor from thiS sector will be enormous. This experiment sought to prove that sodium lignosulfonate (NaLS) derived from hardwood \vould mortar mixture better physical and mechanical propel1ies as compared to commercial sodium lignosulfonate. Lignosulfonate was prepared and mixed at 0.1, 0.2, and 0.3~'~ by weight of the mortar. Mortar made with fine aggregate consisting of portland cement. sand, \vater. and eucalypt sodium-lignosulfonate gave cement setting time up to 500 minutes with a flow diameter of up to 18 cm. indicating satisfactory water dispersion. The mechanica I characteristics of the mortar. in terms of flexural and compressive strength meet the ASTM designation of CI09. C185. e230. and lIS R5201. Therefore, Iignosulfonate derived from hardwood has the potential as a dispersant as compared to commercial NaLS derived from softwood lignin.