FIELD: chemistry.
SUBSTANCE: invention is intended for the chemical industry and can be used in the production of phosphoric acid by kiln firing. Composite pellet are in the form of a ball, the inner ball of which is coated. Inner ball is formed by a carbonaceous reductant powder, a phosphate ore powder, a silica powder and a binder in an amount of 1–12 % by mass of the inner ball material. Shell consists of a cladding material formed by a carbonaceous powder reducing agent, a silica powder and a binder in an amount of 1–12 % by weight of the cladding material. Binder was obtained by mixing humic acid from coal and sodium hydroxide solution, their subsequent reaction and filtration. Phosphate ore powder is obtained by grinding it after accumulation in a homogenizing hopper, treatment with compressed air or continuous homogenization. Inner ball and cladding material are obtained by introducing said powder components into appropriate mixing machines or into wet mills while simultaneously adding binders. Mixed inner ball material is then weighed, loaded into a granulator with the addition of a binder in a drop-like and / or foggy form, the obtained granules are then sorted and coated with the resulting cladding material in a granulator with the addition of a binder. Resulting composite green spheres are dried to dehydrate them.
EFFECT: invention makes it possible to improve the properties and characteristics of the resulting composite pellets.
17 cl, 6 dwg
