混砂工艺对粘土湿型砂性能的影响

Influence of Mulling Sand Process on Green Sand Properties

通过采用 5种不同的加料顺序 ,并改变混砂时间 ,研究了混砂工艺对粘土湿型砂性能的影响。结果表明 ,型砂各性能均随加料顺序和混砂时间的不同而变化。当型砂中不含煤粉时 ,采用先干混后湿混的工艺 ,型砂性能较好 ;当型砂中含有煤粉时 ,采用原砂和水先湿混 ,然后再加膨润土、煤粉的混制工艺 ,型砂性能较好 ;煤粉的介入与未加煤粉时比 ,除透气性外 ,其他各性能均有提高 ;随混砂时间延长 ,各性能均呈上升趋势 ,当混砂时间为 8～ 16 min时 。

Effect of mulling sand process on green sand properties is studied through adopting five different charging sequences and varying mulling time.It is shown that properties of green sand vary with charging sequence and mulling time.When there is no coal dust in molding sand,it is better that water is mixed at last;if molding sand contains coal dust,to achieve better properties of molding sand,sand and water should be mixed first,and then bentonite and coal dust are added Properties of green sand that contains coal dust,except permeability,have increased as compared with no coal dust sand All the properties of green sand tend to increase with mulling time being prolonged and become steady when mulling time reaches 8~16 minutes.