| With the increasing urgency of current environmental protection,the disposal of environmental hazardous wastes has become a special concern of country,and it is also the most troublesome issue for the related companies.Owing to the severe imbalance in coal,gas,and oil reserves of China,the absolute wealth of coal resources must be transformed into natural gas,oil,and the downstream industry productions.The coal chemical industry has spread all over the country.The treatment issue of coal chemical slag(containing coal liquefaction slag and coal gasification slag)has become an important bottleneck whether coal chemical enterprises can normally produce.Therefore,how to effectively use coal chemical slag has become the focus of attention.Inorganic mineral fillers are widely used in polymer composite materials,but there are also some shortcomings and deficiencies in the use of inorganic mineral fillers,such as high production costs,pollution of the ecological environment,consumption of mineral resources,high prices,poor dispersion and high density.Therefore,it is necessary to develop a low-cost and high-value-added filler product.At present,there are many researches on the application of coal chemical slag,but there are few researches on the application of coal chemical slag as rubber and plastic filler.Therefore,this article takes a kind of coal chemical slag,which is coal gasification fine slag as the target treatment,and explores whether coal gasification fine slag can be used as rubber and plastic filler.The coal gasification fine slag from the coal gasification plant of Inner Mongolia Yitai Group Co.,Ltd.was selected as the research object.The physical and chemical properties of the gasification fine slag were studied in detail.As a result,it was found that the coal gasification fine slag is suitable as a rubber and plastic filler.The coal gasification fine slag contains the rough unburned carbon,which is favorable for the compatibility with the polymer matrix.The glass beads in the gasification fine slag have a higher chemical reactivity,which can increase the amount of reactivity site with the polymer matrix and binding strength.Glass beads have a spherical morphology.Compared with the heavy calcium carbonate,there are no sharp edges and corners,so it will not damage the molecular structure of the polymer chains in rubber and plastic processing.The surface of glass beads has a higher surface energy and uniformly distributed hydroxyl groups.The glass beads can be modified to improve product quality.Using gasification fine slag as raw materials,the mesoporous silicon spheres with holes on the surface can be prepared,which can increase intertwining with the polymer chains.The low density polyethylene/coal gasification fine slag composites were prepared by blending the gasification fine slag into the low density polyethylene matrix by a twin-screw extruder.The coal gasification fine slag was processed by a gas flow classification technology to obtain gasification fine slag with the different particle sizes.The results show that the tensile strength of the composite materials increases with the decrease of the particle size of the coal gasification fine slag,and the gasification fine slag with a smaller particle size has a significant strengthening effect for the composite.The tensile strength of the composites was analyzed by the Turcsanyi empirical model,and it was proved that the unburned carbon can increase the interface interaction parameter of the composites.Using 2500 mesh heavy calcium carbonate as a comparative filler,the mechanical properties,thermal oxidation stability,and fracture surface morphology of the composite were analyzed and compared.The research results found that the coal gasification fine slag with a smaller particle size and the unburned carbon can be used to substitute 2500 mesh heavy calcium carbonate in low density polyethylene products.The coal gasification fine slag was calcined to obtain coal gasification fine slag glass beads.The glass beads were subjected to gas flow classification for obtaining glass beads with different particle sizes.ABS resin/glass bead composites were prepared by a twin-screw extruder.The study found that glass beads with different particle sizes can well disperse in the ABS matrix,and the better dispersion state makes the transferring efficiency of interfacial load higher.As the particle size of glass beads decreases,the mechanical strength of the composite materials increases,and the compatibility between glass beads and ABS resin also increases.Combining the data of mechanical strength,processing fluidity and density values of the composite materials,it can be concluded that the glass beads with large particles removed have the potential to replace 2500mesh heavy calcium carbonate in ABS resin.Polypropylene/coal gasification fine slag glass bead composite was prepared by a twin-screw extruder.The glass beads improve the thermal stability of the matrix.From the perspectives of tensile properties and interfacial interaction parameter,the glass beads can be used in polypropylene products to replace 2500 mesh heavy calcium carbonate.The silane coupling agent KH570 and hydrochloric acid solution were used to modify and activate the glass beads.KH570can form an organic film on the surface of glass beads,which can improve the hydrophobic properties of glass beads.Glass beads were treated with hydrochloric acid solution to prepare disordered mesoporous silicon beads with pores on the surface,and its specific surface area was300.463m~2/g.After the modification and activation,the various properties of the composite materials were significantly improved,and the effect of the activation of hydrochloric acid solution is better compared with the effect of KH570 modification,which indicates that the influence of surface morphology of the filler is more significant than that of the surface functional groups for the properties of composites.The modification and activation of the filler can improve the interfacial adhesion of the composites,and as the interface interaction increases,the mechanical strength of the composite will increase and the elongation at break will decrease.Styrene butadiene rubber/gasification fine slag composites were prepared by internal mixer and open mill.The study found that,with the increase of the unburned carbon content and the decrease of the particle size,the comprehensive properties of composite materials gradually improved.The three-dimensional network structure formed by unburned carbon and glass beads can promote the uniform dispersion of gasification fine slag in styrene butadiene rubber,thereby effectively preventing stress concentration.Due to the good dispersibility and strong interfacial adhesion,the comprehensive performances of coal gasification fine slag filled composites are better than that of 2500 mesh heavy calcium carbonate filled composites.Gasification fine slag containing the unburned carbon has a semi-reinforcing effect on styrene butadiene rubber matrix,which can be used in rubber products to substitute heavy calcium.Glass beads activated by hydrochloric acid solution have a good reinforcement effect in polypropylene,but its reinforcement effect is poor in the styrene butadiene rubber system.The paper uses coal gasification fine slag as raw material,and adopts low-cost and simple washing,modification and activation processes to successfully prepare low-cost and high value-added rubber and plastic filler products.The paper provides theoretical supports for the application of coal gasification fine slag in polymers,and also provides new ideas for the treatment of coal gasification fine slag.This not only solves the problem of stacking treatment of coal gasification fine slag,at the same time,an excellent rubber and plastic filler material has been found,which has a significance in promoting the rubber and plastic industry. |
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