SLURRY DECANTATION METHOD, SLURRY OBTAINED USING THAT METHOD AND THEIR USE Russian patent published in 2008 - IPC C02F11/14 C02F1/56 

FIELD: chemistry.

SUBSTANCE: invention pertains to decantation of slurries, initial pH of which is less than or equal to 8. Such slurries can be formed on treatment plants of municipal effluents, and industrial effluents. The slurry decantation method involves addition of an alkaline reagent in slurry with pH of 8 or less, adding to the slurry of at least one flocculent organic component, increase of the pH of the slurries through addition of an alkaline reagent up to the value less than the pH at which disintegration of at least one organic compound starts, flocculation of slurries and separation of flocculated slurries into dehydrated slurries and a liquid phase. The alkaline reagent is in form of a lime-magnesian compound with formula: xCaCO₃(l-x)[yMg(OH)2+(l-y)MgO], where x, y are molar ratios, and 0.45≤x≤0.75 and 0≤y≤1. After separation, the processed slurries have pH, which is less than the pH at which disintegration of at least one organic component starts.

EFFECT: increased degree of slurry decantation with use of common flocculants and obtaining of slurries with optimum technological properties - stability in bulk conditions, capacity to pelletising.

11 cl, 3 ex