黏结剂对免烘干型煤强度的影响

Effects of Binders on Strength of Non-drying Briquette

利用黄原胶基黏结剂和聚乙烯醇基黏结剂制备免烘干型煤,确定最佳黏结剂配方并进行黏结机制研究。结果表明:黄原胶基黏结剂各组分的质量占型煤质量的百分比为黄原胶1.0%、蔗糖0.6%、钠基膨润土3.0%时,型煤湿强度为43.3 N/个;聚乙烯醇基黏结剂各组分的质量占型煤质量的百分比为聚乙烯醇1.5%、快干水泥3.0%时,型煤湿强度为83.7 N/个;在自然晾干条件下24 h内黄原胶基型煤强度可达到130 N/个,聚乙烯醇基型煤强度可达到300 N/个;黏结剂可充分填充到煤粒间隙中,与型煤中部分自由水结合生成结合水,从而在未烘干条件下快速提高型煤强度,黏结剂与煤粒结合没有产生新的化学键,黏结剂在煤粒间形成的骨架结构可使型煤保持一定的强度。

Xanthan gum-based binder and polyvinyl alcohol(PVA)-based binder were used to make non-drying briquette,the optimal binder formula was determined.The results show that with the composition of the xanthan gum-based binder includes 1.0%xanthan gum,0.6%sucrose and 3.0%sodium bentonite,the wetting strength of the coal briquette is 43.3 N/ball.When the composition of the PVA-based binder includes 1.5%PVA and 3.0%quick drying cement,the wetting strength of the coal briquette is 83.7 N/ball.The strengths of the xanthan gum-based briquette and PVA-based briquette reach 130 N/ball and 300 N/ball,respectively,within 24 h under the natural air drying condition.The binder can fully fill the gap among coal particles and combine with part of free water to form bound water,rapidly improving the strength of the briquette without drying.There are no new chemical bonds between binder and coal particles,and the skeleton structure formed by the binders among coal particles can maintain certain strength of the coal briquette.