| 摘要 |
In a pulping process comprising: a step (2) of digesting a lignocellulosic substance (F) using a digesting liquid; steps (3, 4) of separating the digested product into pulp and a waste digesting liquid; steps (5, 9) of treating the waste digesting liquid with a magnesia adsorbent to adsorb at least part of organic substances in the waste liquid; steps (6, 10) of separating the adsorption product into a phase rich in an organic substance-adsorbing adsorbent and a liquid phase wherein a magnesium component is dissolved; and a step (8) of burning at least part of the organic substance-adsorbing adsorbent to regenerate the adsorbent, an improvement which comprises adding, upon separating the adsorption product, an alkaline substance to this adsorption product to increase its pH, whereby at least part of the dissolved magnesium component is precipitated. This addition serves to reduce the magnesium concentration in the liquid phase discharged from the steps (6, 10) of separating this adsorption product. |
