Síntese e caracterização de bioaditivo com lignina para cimentação de poços

Abstract

Inadequate management of agro-industrial waste is a growing challenge, especially in Brazil. The tannin industry is well established in the country and uses forest residues as raw material, but after extraction, the solid material has no defined destination. In order to improve the tannin production chain, the present study aimed to develop a bioadditive for cements from the residue of Anadenanthera colubrina (red angico bark). Initially, the chemical composition of the lignocellulosic byproduct was determined by chemical analysis and thermogravimetric analysis (TGA/DTG). Then, lignin was isolated by alkaline extraction followed by acid precipitation. The bioadditive was synthesized from this lignin, aiming at specific properties for application in cement. The effectiveness of the bioadditive was confirmed in cement pastes by rheological and consistometric tests, analyzing its retardant effect and concentration. It was observed that the bioadditive reduces the interaction between cement particles, prolonging the setting time and improving hardening control, which contributes to the quality and resistance of the cement in cementing operations.