【摘要】 用一定浓度的醋酸钙和氢氧化钠溶液与酸洗脱灰处理后的低阶烟煤在煮沸的条件下分别进行离子交换,测定羧基的滴定终点由空白试验的pH值确定,而总酸性基的滴定终点由酚酞指示剂确定;筛选了不同浓度和煮沸时间对测定结果的影响.结果表明:醋酸钙溶液在0.15 mol/L、煮沸2 h,氢氧化钠溶液在0.25 mol/L、煮沸1 h分别可得到较准确的羧基和总酸性基含量.3种低阶烟煤中羧基含量均在0.2 mmol/g以下,而酚羟基含量在2耀4 mmol/g,且酸性官能团中的氧元素占干燥无灰基煤中总氧含量的50%耀60%,得到了一种比较准确的测定低阶烟煤中酸性含氧官能团的方法.更多还原

【Abstract】 Calcium acetate and sodium hydroxide solution with different concentrations mixed with three demineralized lowrank bituminous coals were boiled respectively in order to ion exchange with carboxyl and total acids functionalgroups. The titration end of carboxyl and total acids functional groups were controlled by the pH of calcium acetatesolution and phenolphthalein indicator respectively. It showed that correct carboxyl content was obtained at 0.15mol/L calcium acetate and 2 h boiling time曰 total acids functional groups were obtained at 0.25 mol/L sodiumhydroxide and 1 h boiling time. The carboxyl content was lower than 2 mmol/g and the phenolic hydroxyl contentwas between 2 and 4 mmol/g曰 the oxygen in total acids functional groups was more than half in three low rankbituminous coals (dry ashes free basis). An accurate method for measuring acidic functional groups in low rankbituminous coals was obtained.更多还原