| 摘要 |
This invention is dealing with a method for producing a sorbent for removing and immobilisation of cations of the heavy metals and/or phosphates in contaminated solids and/or liquids. The sorbent according to this invention is a composite granular material consisting of a carrier of schistous nature or related to the wastes from coal dressing, an active component - thermally modified dolomite with a high content of MgO.CaCO3, and a binding agent - preferably cement. First of all, carrier and an active component with grain's size less than 0.2 mm are mixed together; then cement is added and a dry three-component mixture with a composition given by the mass ratio (carrier):(active component):(binder)=(1.3 to 4.3):(1.0 to 1.3):(1.0 to 1.5) is prepared. After adding a certain amount of a water, a mass of paste-like consistency with a composition given by the mass ratio (solids):(water)=(1):(0.38 to 0.60) is obtained. The latter one - after previous setting and hardening (3 to 10 days) - is crushed and screened into fractions with defined grain size, preferably (1.0 to 3.0), (0.3 to 1.0) and (0.0 to 0.3) mm. Grading of used sorbent is determined by its assumed application for purification of contaminated solids or liquids. The sorbent according to this invention is used as a filter body (matrix) material for purification of contaminated liquids in dynamic conditions, as an additive to contaminated liquids in settling tanks in static conditions, or - in a pulverized form - as an additive for removing and immobilisation of the heavy metals and/or phosphates in contaminated solids. |
