Analysis Of Coal Quality And Water Quality Of Inner Mongolia Lignite Dehydration Upgrading

Lignite,the main coal type of domestic coal resources,is mainly distributed in the water-deficient areasand the unreasonable phenomenon of the so-called ‘coal surplus,water deficient' is sever and ordinary in China.For example,the reserve of lignite in Inner Mongoliais able to reach up to approximate 80% of the reserve of overall domestic lignite.Taking the regional environmental protection and the development of future coal-related industries into consideration,it is important and necessary to conduct a study to research proposed methods for making full use of the watercontained in lignite and then reducing the primary water consumption.In this study,the studied coal samples wererespectively supplied from Chifeng,Hunlun Buir,and Erdos(three areas of Inner Mongolia)and used as received.After dehydration upgrading,water contents of these three kind of lignite were reduced and calorific values were increased.Consequently,overall utilization efficiencies were enhanced.Particularly,the experimental results showed that the lignite sample from Hunlun Buir has performed the best upgrading performance among these three kind of samples and consequently it was proposed to be used as the batch material to conduct the following researches.By comparing the practicability and economic efficiency of microwave dehydration,evaporation,and heat-pressing dehydration,the traditional evaporation was chosen as the proposed hydration method in this study.After the condensation process,the moisture contained in the dried tail gas was recovered and subsequently to be used to conduct the water quality analysis.The results of the water quality analysis showed that the COD and organic components of the collected water were high and consequently the recovered water could not be reused directly.In this regards,a purification scheme composed of filtration,adsorption,and catalytic oxidation processes was designed to improve the water quality of the condensed water and the purified water was capable ofsatisfying the standard of industrial secondary water.In conclusion,this study has offered experimental data support for the industrial recycle and reuse of the dehydrated water from coal.