Experimental Study On The Comprehensive Utilization Of The Acid Tar To Prepare The Water-reducer

At present, the rapid development of coarse benzene industry lead to substantial waste acid.The ingredients of waste acid is very complex. It is hard to be treated and it is utilized lowly.The most of them were abandoned and stockpiled. The large pile of waste acid not onlyoccupies the land, but also pollutes the environment and affects sustainably the development ofthe benzene industry. As the requirement of the waste acid processing on environment andenergy conservation and cost reduction, the reasonable and efficient utilization of waste hasbecome a hot scientific research areas.The concrete water reducer was made by the refining benzol waste acid from CokingPlant. Research on Cement paste mixed with tar acid water reducing agent of paste structurewas done by SEM and other modern analytical methods. The relationship between acid tarreducing agent working principle and performance was analysed. The performance of acid tarreducing agent was compared with water reducing agent sold on the market. The acid tar waterreducing agent was used in the concrete in order to achieve the high value-added using of wasteacid.The acid tar is condensated by using formaldehyde as condensation agent, and gotconcrete water reducer has good performance. The influence level of each factor wasdetermined by single factor experiments, and the optimum preparation conditions of tar acidconcrete water reducer was obtained by the orthogonal experiment: the mol ratio offormaldehyde to acid is0.8, the condensation temperature was55to60℃, the condensationtime was2.5hour, acidity of the solutions was29%. The cement net fluidity of the preparationconcrete water reducer was225mm. The influence degree of four factors on the concrete waterreducer was determined: the mol ratio of formaldehyde to acid> condensation temperature>condensation time> acidity of the solutions.The concrete water reducer scientific effective was research by the article. The property ofconcrete water reducer was largely enhanced by adding FDN. The result show that undercertain conditions the performance of water-reducing rate and compatibility with cement can beimproved through thermal compound, and the slump loss with increasing time can be reduced.Compare with the cement paste without water reducer added, the microstructure of cementpaste with water reducer added was strongly changed. The small particles in the structure of thecement paste was increased, and the particle sizes of microspheres become smaller, and occurrence of voids between particles. The concrete water reducer altered the surface electricalcontacts and the forces of cement particle. The concrete structure was destroyed by electrostaticrepulsion and sterically hindered. The cement particle is parochial and fragmented. It attainedthe peculiar quality of reducing water. So it can be used as concrete water reducer.The study provided a new process route to achieve the utilization of high value-added. Thewater reducer applied to concrete industry was feasible in technology design and will have agood application prospect.