反渗透浓水用于水煤浆制备及其对流变性的影响

Reverse osmosis concentrated water applied to preparation of coal water mixture and affected to rheology

为了解决反渗透浓水制约现代煤化工园区废水零排放的问题,将反渗透浓水回用于水煤浆制备。选用烟煤和褐煤作为混合煤样,通过调整反渗透浓水添加比例验证其成浆性,并分析Ca^(2+)浓度对水煤浆流变性的影响。试验结果表明:随着投加反渗透浓水水量的增加,制浆浓度不断增加,其流变性越来越差。为了保证在剪切率100 s^(-1)时表观黏度不超过1 200 m Pa·s,反渗透浓水的投加比例不宜超过50%;随着Ca^(2+)质量浓度从0增加到1 867.40 mg/L,水煤浆表现黏度从1 041 m Pa·s提高到1 468 m Pa·s,表明Ca^(2+)可以中和煤颗粒表面负电荷,不利于黏度降低,导致流动性变差。

In order to solve the problems of reverse osmosis concentrated water to restrict the waste water zero emission realized from mod- em coal chemical industrial park,the reverse osmosis concentrated water was retuned to the preparation of the coal water mixture.The bitu- minous coal and lignite coal were selected as the mixed coal samples,the percentage adjustment of the reverse osmosis concentrated water was applied to verify the slurryability and to analyze the calcium ion concentration affected to the rheology of the coal water mixture.The ex- periment results showed that with the water quantity added to the reverse osmosis concentrated water increased, the mixture concentration would be continuously increased and the rheology would be worst and worst.In order to ensure the apparent viscosity would not be over 1 200 mPa ~ s when the shearing rate was 100 s^-1 ,the added percentage of the reverse osmosis concentrated water should not be over 50%. With the calcium ion concentration increased from 0 to 1 867.40 mg/L, the apparent viscosity of the coal water mixture would be improved from 1 041 mPa · s to 1 468 mPa · s.The above showed that the calcium ion could neutralize the negative electric load on the surface of the coal particles and would not be favorable to reduce the viscosity, So the fluidity of the coal water mixture became poor.