Study On The Comprehensive Utilization Of A Coal Gasification Slag In The North

Coal gasification slag is a large mount solid waste,especially in north China.Coal gasification slag amount is huge and has yet to be usedeffectively.It not only takes up a lot of land,also cause serious damage to the environment.For this status,this paper systematically study on the comprehensive utilization of it.First of all,material composition characteristics of coal gasification slag from north China was studied.Based on this,this paper studied systematically onselecting out of concentrate carbon from coal gasification slag flotation,activated carbon from concentrate carbon and magnetic activated carbon process,flotation tailings as cement mixed material.The results of the study have important reference value for the comprehensive utilization of coal gasification slag.Composition features of coal gasification slag contain main chemical composition:SiO2,A12O3,Fe2O3,CaO,SO3,CO2.Mainly is the amorphous,contains a small amount of crystalline minerals such as quartz,calcite.Research on coal gasification slag flotation results shows that under the condition of the dosage kerosene 10 kg/t,2#oil consumption 1.5 kg/t,granularity the D90 = 123μm,the concentrate coal loss is 85.03%,the yield of 21.81%.The resultof activated carbonform concentrate carbon prepared showed that the activated carbon by KOH activation method,under the condition of the alkali carbon ratio 2,activation temperature 800 ℃,activation time 1.50 h,the specific surface area of activated carbon is 1226.76 m2/g,the entrance is 0.694 cm/g,and the porosity is given priority to with micropore and the mesoporous.Activated carbon by CO2 activation method,under the conditions of temperature 900.0 ℃,2.00 h.CO2 ventilation time 0.80 L/min,its specific surface area was 533.2 m2/g,including micropore accounted most.The research results of prepared magnetic activated carbon by the one-step,theconcentrate carbon as raw material show that under the condition of the CO2 ventilation 0.8 L/min,activation temperature 900 ℃,holding time 2 h,CoFe2O4 adding amount 12.6%,the magnetic activated carbon specific surface area was 425 m/g,magnetic recovery rate reached 90.36%;the research results of the preparation of magnetic activated carbon by adsorption method,activated carbon prepared by KOH activation method as the raw material show that under the conditions of the CoFe2O4 adding amount 20%,magnetic activated carbon the iodine adsorption value was 873 mg/g,methylene blue adsorption value was 146 mg/g,magnetic recovery was 91.35%.The research resultsof two kinds of carbon adsorption materials(activated carbon,magnetic living standard c)used to simulate the dyeing wastewater treatment shown that under the same conditions,the two kinds of adsorption materials have significant differences on the removal rate of methyl orange in the solution:activated carbon by the KOH activationmethod>magnetic activated carbon by adsorption method>active carbon adsorption CO2 activation method>one-step magnetic activated carbon,theyhavegood treatment effect.Flotation of concentrate carbon has good processing effect on the simulated dyeing wastewater,and adsorption process of concentrate carbon dyeing wastewater accord with the Langmuir adsorption model and the secondary dynamic equation.The research results of flotation tailings as cement mixed material show that the tailings fineness is smaller,the activity indexis greater,when the D90 = 41.21um,active index is 81.8%;Tailings dosage is the greater,the compressive flexural strength of the specimens is smaller,when the tail slag content is less than 10%,the compressive strength is greater than the benchmark cement.