Method for granulating, molding and calcining ground phosphorite

Abstract

The invention relates to a method for granulating, molding and calcining ground phosphorite. The method comprises the steps of crushing phosphorite, screening, drying and carrying out homogenizing pretreatment to obtain ground phosphorite, feeding the ground phosphorite into a ball mill for grinding, adding fine ground phosphorite into a circular-disc granulator, evenly adding a binder prepared from an intermediate product acid slag in production of phosphoric acid by virtue of a dihydrate wet process in proportion so that the fine ground phosphorite is bound with each other and phosphorite pellets of which the particle sizes reach 20-30mm are prepared, introducing phosphorus furnace tail gas into a chain-grate-type calcining machine, calcining at a temperature of 850-950 DEG C and cooling with air to obtain the phosphorite pellets for production of yellow phosphorus. According to the method, the intermediate product in the production process is fully utilized, is processed into an auxiliary material and directly returns back to the production process, newly added other raw auxiliary materials and the consumption of energy, such as coke powder are not needed; by virtue of phosphorus furnace tail gas and unique calcining and air cooling processes, the content of P2O5 in the ground phosphorite pellets is increased by 8-10% and the silicon-calcium ratio (acidity coefficient Mk) in the phosphorite pellets is not increased, and thus the efficient comprehensive utilization of phosphate resources is achieved.

Description

technical field [0001] The invention relates to a method for granulating, forming and roasting phosphate rock powder, which belongs to the technical field of phosphorus chemical industry. technical background [0002] Phosphate rock is mined, transported, and put into the furnace after crushing, drying, screening and other processing in the factory. The amount of lump ore is only about 50%. If the qualified lump ore is purchased to make phosphorus, it usually loses 15%. ~20%, the remaining phosphate rock powder screened by yellow phosphorus production enterprises is huge, and if it is not used, it will cause great waste of phosphorus resources and serious economic losses. The "Yellow Phosphorus Industry Access Conditions" implemented by the state clearly requires that the mineral powder utilization rate of yellow phosphorus enterprises must reach 100%. Some yellow phosphorus production enterprises try to use phosphate rock powder plus clay or water glass as a binder, then g...

AI Technical Summary

Problems solved by technology

CN 102381690 discloses a medicine made of rare earth elements, sodium chloride, calcium chloride, zinc chloride, sodium carbonate and potassium carbonate in proportion to montmorillonite powder, which is mixed, matured, dried and ball-milled into powder The phosphate rock powder oxygen-enriched binder produced has many defects such as the addition of many raw materials, the lengthy and cumbersome production process, and the difficulty in controlling the chemical composition of the finished product and waste after high-temperature reaction and additional follow-up treatment.

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