| 摘要 |
<p>PURPOSE:To separate heavy metals from a waste water at a high efficiency and at a low cost, by adding to a heavy metal ion-containing waste water a coal for ex- clusively burning waste pulp solution to adsorb heavy metals onto said coal, separating the mixture to a solid part and a liquid part, and then baking the adsorbed substances. CONSTITUTION:The coal for exclusively burning a waste pulp solution is added to waste water containing heavy metals, to adsorb the heavy metals from the waste water to said coal. The adsorbed substances are baked, and the heavy metals are recovered as an ignition residue. The coal for exclusively burning the waste pulp solution is a residual carbon by-produced in a process of concentrating a waste semi-chemical pulp solution to 50% or so of solid suspensions, reducing calcining the concentrated solution at 700 deg.C or so, separating the calcination product to a gaseous part and a solid part with a cyclone, and reacting again SO2, the main component in the gaseous part, with Na2CO3, the main component in the solid part, to recover the reaction product as Na2SO3. After the addition of the coal for exclusively burning the waste pulp solution, the mixture is preferably agitated about 10-30min, and then separated to a solid part and a liquid part.</p> |
