高钠煤水热脱钠处理及其对燃烧特性的影响

Hydrothermal treatment to remove sodium from high sodium coal and its influence on combustion characteristics

以五彩湾高钠煤为研究对象,根据煤中钠的赋存形态,分别研究了不同条件下水洗和水热处理两种方式对碱金属的脱除效果,同时考察了水热处理对煤燃烧特性的影响。结果表明,五彩湾煤中钠主要以水溶性钠盐存在;单纯水洗对Na的脱除效果不理想,并且工艺耗时长、耗水量大;水热处理脱钠效率高,钠脱除率高达90.5%,处理后的煤灰中Na2O含量降至0.7%,属于低钠煤范围;水热处理后煤样的燃烧速率曲线移向低温区,燃烧特性优于原煤。

Considering the form of sodium existing in coal, series of water washing and hydrothermal treatments were used to remove alkali metals from a high sodium coal from Wucaiwan.The variation of combustion characteristics of coal after pretreatment was investigated.The results show that the sodium in the coal mainly exists as water-soluble form.The Na removal ratio by water washing treatment does not reach the expectation with the characteristics of time consuming and high water consumption.The hydrothermal treatment is effective in sodium removal as high as 90.5%, and Na2 O content in the ash decreases to 0.7% which belongs to the scope of low sodium lve el in coal sa h.The burnign curves of coal samples after hy drothermal treatment move to the low temperature zone, andt he combuts ion characteristics is improved compared with raw coal.