管输煤浆提浓制备气化水煤浆的工艺条件研究

Study on the characteristics of gasified coal water slurry preparation by condensing coal slurry

管输煤浆需经提浓方可保证水煤浆的气化效率与经济性,因而很有必要考察不同原料配比、添加剂比例等工艺条件对制备高浓度气化煤浆的影响规律。以神渭管输煤浆脱水后的离心煤和压滤煤为原料,研究管输煤浆提浓工艺中制备压滤细煤浆的添加剂比例及最高成浆浓度、制备气化煤浆的最佳配比及添加剂添加量,通过对单独压滤细煤的成浆性实验、细浆和超细浆掺混比例实验、离心煤、压滤煤、细浆和超细浆最佳配比实验的设计,借助旋转黏度计、流动性测试仪、标准筛网等探索压滤细煤浆和气化煤浆的制备工艺条件。结果表明,在制备压滤细煤浆时,添加剂比例不得低于0.2%,干基最佳添加比例为0.5%,制得压滤细煤浆浓度为55.21%;在制备气化水煤浆时,离心粗煤、压滤细煤浆、细浆和超细浆的最佳配比为70∶20∶5∶5,干基添加剂总添加量为0.4%,在制备压滤细煤浆和制备气化煤浆时按比例为3∶5分2次加入。物料衡算表明,将浓度未53%的管输煤浆全部脱水后再按合理的级配制备为气化水煤浆,可在实现富余管输煤浆全部制备为高值气化水煤浆的同时消纳利用全部压滤细煤泥。

It is necessary to investigate the influence of different raw material ratios,additive ratios and other process conditions on the preparation of high concentration gasified coal water slurry,as it is necessary to ensure the gasification efficiency and economy of coal water slurry through thickening during pipeline transportation.In this paper,using centrifugal coal and filter coal dehydrated from the Shenwei pipeline coal slurry as raw materials,the additive ratio and maximum slurry concentration for preparing filter coal slurry in the pipeline coal slurry thickening process,as well as the optimal ratio and additive dosage for preparing gasification coal slurry,were studied.Through experiments on the slurryability of individual filter coal,the mixing ratio of fine slurry and ultra-fine slurry,and the optimal ratio of centrifugal coal,filter coal,fine slurry and ultra-fine slurry,the design of the experiment was carried out,the preparation process conditions for fine coal slurry and gasification coal slurry were explored using rotary viscometers,flowability testers,standard sieves,etc.The results show that when preparing pressure filtration fine coal slurry,the additive ratio should not be less than 0.2%,and the optimal addition ratio is 0.5%,resulting in a pressure filtration fine coal slurry concentration of 55.21%;when preparing gasification coal water slurry,the optimal ratio of centrifugal coarse coal,pressure filtration fine coal slurry,fine slurry,and ultrafine slurry is 70∶20∶5∶5,and the total amount of dry based additives is 0.4%.When preparing pressure filtration fine coal slurry and gasification coal slurry,the ratio is 3∶5 and added twice.The material balance calculation shows that by dehydrating all the coal slurry with a concentration of less than 53%and then preparing it into gasification coal water slurry according to a reasonable grade,it can achieve the goal of preparing all the surplus coal slurry into high value gasification coal water slurry while also consuming and utilizing all the fine coal slurry under pressure filtration.