MULTILAYERED PROPPANT AND METHOD FOR OBTAINING IT Russian patent published in 2015 - IPC B01J2/00 C09K8/80 C04B35/64 

FIELD: chemistry.

SUBSTANCE: invention relates to production of proppants, used in petroleum and gas extraction by method of hydraulic fracturing. Multilayered proppant is obtained on the basis of sintered aluminosilicate raw material in form of granules, with pycnometric density 2.0-3.5 g/cm³ and size 0.2-2.5 mm. Proppant consists of core and two layers - inner and outer, with core consisting of mixture of aluminosilicate raw material and pore-forming agent, inner layer above core consists of mixture of aluminosilicate raw material and mineraliser, outer layer consists of mixture of aluminosilicate raw material and fluorite. in method for obtaining multilayered proppant, including granulation of mixture of aluminosilicate raw material with pore-forming agents, mineralisers and fluorite with addition of binding component in mixer-granulator with rotating at constant rate disc bowl and rotor mixer, rotation rate of which is changed depending on granulation stage, drying at 110-300°C, sieving of dried granules, burning of granules in rotating furnace, sieving burnt granules into marketable fractions, granulation is carried out in three stages: at first stage mixture of aluminosilicate raw material and pore-forming agent is granulated, at second stage mixture of aluminosilicate raw material and mineraliser is granulated, at third stage mixture of aluminosilicate raw material and fluorite is granulated.

EFFECT: invention makes it possible to obtain proppant with low pycnometric density and high mechanical strength.

13 cl, 1 tbl