FIELD: chemistry.
SUBSTANCE: invention can be used to produce a pigment suitable in making paper for ink-jet printing. Precipitated calcium carbonate is obtained by mixing quicklime with water in a reactor or a tank with a mixer, followed by filtration of the calcium hydroxide suspension to remove all residual contaminants and/or non-reactive quicklime. The filtered suspension is then fed into a stainless steel reactor fitted with a mixer. Temperature is kept in the range of 10-70°C, after which the suspension is fed into a carbonisation reactor, where a carbon dioxide-containing gas is bubbled through the suspension. The carbonisation step is carried out at carbonisation gas flow rate of less than 30 litres per minute per kilogram of calcium hydroxide during precipitation under normal conditions. The suspension is removed from the tank when conductivity reaches the minimum level and pH drops below 8, wherein large particles are removed through a filter. The obtained calcium carbonate can be used as a pigment.
EFFECT: invention improves the quality of ink-jet printing while reducing the cost of production of paper for ink-jet printing.
15 cl, 5 dwg, 17 tbl, 9 ex
