Method for producing sodium dithionite
    12.
    发明授权
    Method for producing sodium dithionite 失效
    生产连二亚硫酸钠的方法

    公开(公告)号:US07968076B2

    公开(公告)日:2011-06-28

    申请号:US11666973

    申请日:2005-11-03

    IPC分类号: C01B17/66

    CPC分类号: C01B17/66

    摘要: The invention relates to a process for the preparation of sodium dithionite, comprising the steps (a) provision of a synthesis batch comprising sodium formate, sulfur dioxide and an alkaline sodium compound in aqueous methanolic solution with formation of a sodium dithionite mother liquor, (b) isolation of sodium dithionite from the sodium dithionite mother liquor, a residual mother liquor being obtained, (c) separation of methanol from the residual mother liquor, (d) separation of the residual mother liquor into a thiosulfate-rich first part-stream and a thiosulfate-poor, formate-containing second part-stream by means of nanofiltration, (e) concentration of sodium formate in the second part-stream and (f) recycling of the concentrated second part-stream to process step (a).

    摘要翻译: 本发明涉及一种制备连二亚硫酸钠的方法,包括以下步骤:(a)在形成连二亚硫酸钠母液的水溶液中提供包含甲酸钠,二氧化硫和碱性钠化合物的合成批料,(b )从连二亚硫酸钠母液中分离连二亚硫酸钠,得到残余母液,(c)从残余母液中分离甲醇,(d)将残余母液分离成富含硫代硫酸氢盐的第一部分流, (e)在第二部分流中浓缩甲酸钠,和(f)将浓缩的第二部分物流再循环到工艺步骤(a)中,通过纳滤法生产含有硫代硫酸盐的富含甲酸的第二部分物流。