压力对煤在典型基体材料上冻粘强度的影响分析

Influences of the pressure on freezing adhesive strength of coal on typical matrix material

为分析压力对煤在典型基体材料上冻粘强度的影响规律与原因,对不同压力下煤样在亲水性Q235基体材料和疏水性UHMWPE基体材料上的冻粘强度进行实验。实验数据表明:在两基体上煤样冻粘强度均随压力的增加而逐渐增加,Q235基体材料上冻粘强度大小约为UHMWPE基体冻粘强度的10倍;在Q235材料上,当煤样压力从0MPa增至0.75MPa时,冻粘界面处的煤泥冰大量增多,使其自身强度迅速增加,同时界面直接接触部位变得紧密,导致冻粘强度迅速增加,当压力从0.75MPa增至5MPa时,煤泥冰自身强度缓慢增加,导致冻粘强度缓慢增加;在UHMWPE材料上,当煤样压力从0MPa增至1.5MPa时,煤泥冰增多使其与材料表面接触面积迅速增加,直接接触部位也变得紧密,导致冻粘强度迅速增加;当压力从1.5MPa增至5MPa时,冻粘界面水分与材料表面接触更加充分,导致冻粘强度缓慢增加。实际使用中为减少冻粘时矿车或皮带输送机滚筒损伤,应尽量避免在冻粘强度随压力迅速增加阶段提高运煤量或运输功率。

To investigate the influences of the pressure on freezing adhesive strength of coal on typical matrix material, the freezing adhesive strength of coal samples on hydrophilic Q235 and hydrophobic UHMWPE material under a series of different pressure are tested. The freezing adhesive strength of coal samples on the two matrix materials increase as the pressure increases on coal samples, and the freezing adhesive strength of the coal sample on Q235 material is 10 times that of the coal sample on UHMWPE material. On Q235 material, when the pressure of coal samples increases from 0 MPa to 0.75 MPa, the slime and ice of freezing adhesive boundary increase largely and the strength increases rapidly, the direct contact region gets closer, so the freezing adhesive strength increases rapidly. When the pressure of coal samples increases from 0.75 MPa to 5 MPa, the strengths of the slime and ice increase slowly, so the freezing adhesive strength increases slowly. On UHMWPE material, when the pressure of coal samples increases from 0 MPa to 1.5 MPa, the slime and ice of freezing adhesive boundary increase largely and the contact area with material surface increases rapidly, and the direct contact region gets closer, so the freezing adhesive strength increases rapidly. When the pressure of coal samples increases from 1.5 MPa to 5 MPa, the contact of the moisture of freezing adhesive boundary with material surface gets closer, so the freezing adhesive strength increases slowly. For the improvement of the freezing adhesion of mine car and belt conveyor roller, it should be avoided as possible that incresing the coal capacity of mine car or the transportation power of belt conveyor in the rapid increasing stage of the freezing adhesive strength as pressure.