CAJ | 학술논문

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2～4 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%～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.
용일정농도적작산개화경양화납용액여산세탈회처리후적저계연매재자비적조건하분별진행리자교환，측정최기적적정종점유공백시험적pH치학정，이총산성기적적정종점유분태지시제학정；사선료불동농도화자비시간대측정결과적영향.결과표명：작산개용액재0.15 mol/L、자비2 h，경양화납용액재0.25 mol/L、자비1 h분별가득도교준학적최기화총산성기함량.3충저계연매중최기함량균재0.2 mmol/g이하，이분간기함량재2～4 mmol/g，차산성관능단중적양원소점간조무회기매중총양함량적50%～60%，득도료일충비교준학적측정저계연매중산성함양관능단적방법.
Calcium acetate and sodium hydroxide solution with different concentrations mixed with three demineralized low rank bituminous coals were boiled respectively in order to ion exchange with carboxyl and total acids functional groups. The titration end of carboxyl and total acids functional groups were controlled by the pH of calcium acetate solution and phenolphthalein indicator respectively. It showed that correct carboxyl content was obtained at 0.15 mol/L calcium acetate and 2 h boiling time; total acids functional groups were obtained at 0.25 mol/L sodium hydroxide and 1 h boiling time. The carboxyl content was lower than 2 mmol/g and the phenolic hydroxyl content was between 2 and 4 mmol/g; the oxygen in total acids functional groups was more than half in three low rank bituminous coals (dry ashes free basis). An accurate method for measuring acidic functional groups in low rank bituminous coals was obtained.