Preparation And Combustion Characteristic Of Briquette Using Filter Cake With Pulverized Coal

The filter cake(ZNLB)obtained from Zhongneng Chemical co.LTD and JJW coal were selected to produce briquette.The mechanical strength and waterproof of briquette were investigated through changing the mixing proportion of ZNLB and JJW coal,moisture,briquette pressure and different binder.Scanning electron microscopic(SEM)was applied to study the apparent morphology of briquette.The mechanical strength of briquette made by compound binders was analyzed by orthogonal experiment.The combustion characteristics of the filter cake,pulverized coal and mixed samples were studied by synchronous thermal analyzer(TGA).Conclusions were summarized as follows:To meet briquette standard,the maximum addition amount of ZNLB to briquette was 30%(wt%).With the increase of forming moisture and pressure,the compressive strength of briquette firstly increases and then decreases.The compressive strength of briquette could reach to 105N when the forming pressure,the content of forming moisture and clay addition are at 15Mpa,15%and 3%respectively.It was found that the mechanical strength of briquette is influenced significantly by the addition of clay and Pvac binder and the waterproof of the briquette can be improved by adding sodium silicate.When the proportion of binder added to 24%,the compressive strength of the briquette made by clay could reach to about 500N.The falling strength of the briquette made by Pvac was 68%and the briquette made by sodium silicate had good waterproof properties.SEM results showed that the surface morphology of the briquette with non-binder addition was porous,while the surface morphology of briquette with the addition of sodium silicate was smooth and uniform which prevent significantly the briquette from dispersing in water.The mechanical strength of briquette produced by different binders could not meet the standard of briquette.Three kinds of binder were mixed to prepare briquette by orthogonal experiment,.Compared to different binder used alone,the mechanical strength of briquette prepared by compound binders increased at the same addition percentage.When the proportion of compound binder is at about 12%,the compressive strength of briquette could reach to over 800N and the briquette falling strength could be 87%which meets the standard clean briquette for boiler.The TGA was adopted to investigate the combustion characteristic of f the filter cake,pulverized coal and briquette samples.The results showed that the combustible index of JJW is 4.08 X 10'5 higher than that of ZNLB.With the addition content of the ZNLB reaches to 30%in the mixture,the combustible index dropped by 1.45×10-5 compared to that of JJW.The combustibility index of briquette prepared by adding 20%binder reduced in some degree which meet the requirement of briquette combustion.In conclusion,preparation of briquette using filter cake mixed with pulverized coal of is feasible.