| 摘要 |
<p>Mg(HSO3)2 soln. is produced according to the Parent Patent by scrubbing SO2-contg. gaseous effluents with an aq. MgO suspension in a stepwise process, in which SO2 is gradually removed from the gases. In the first stage the gases are scrubbed with a MgSO3 suspension, whereby Mg(HSO3)2 is formed and removed. In the second stage, the gases, contg now a decreased quantity of SO2, are scrubbed with a MgO suspension; the resulting of MgSO3 is sepd., re-suspended in water and passed to the first stage. This process is improved in that gases from a sulphitelye burning installation are first passed through a dust separator (electrofilter or cyclone) and the MgO-contg. dust is re-introduced into the gas stream before the last scrubber where the MgO suspension reacts with the residual SO2 forming MgSO3. The latter is sepd. from the aq. phase, which is discarded to remove from the circulation impurities resulting from the burning of cellulose fibres, other wood components, fuels etc. The loss of the aq. phase is compensated by addition of fresh water. The recovery of chemicals is increased. The purity of the products is improved and good-quality boiling lye is regenerated.</p> |
