基于煅烧磷尾矿的磷石膏无害化处理工艺研究OA

Phosphogypsum is an industrial byproduct in the production process of phosphoric acid,while phosphorus tailings are solid waste generated in the selection process of phosphate ore.The large-scale accumulation of both not only occupies land resources,but also seriously pollutes the environment,restricting the high-quality development of the phosphate chemical industry.In order to achieve the resource utilization of phosphate tailings and the harmless treatment of phosphate gypsum,this paper proposed a new path for the harmless treatment of phosphate gypsum by calcining phosphate tailings.The solidification effect of water-soluble phosphorus and water-soluble fluoride in phos-phate gypsum was explored by the number of water washes,calcination temperature of phosphate tailings,settling time,and dosage of silicate cement.The results showed that once washed phosphorus gypsum was prepared into the slurry with the mass fraction of 30％,mixed with phosphorus tailings calcined at 850 ℃ and 0.5％ordinary silicate cement,stirred,filtered,and left to stand for 3 days,The mass concentration of water-soluble phosphorus in the leaching solution of phosphogypsum was lower than the detection limit,and the mass concentration of water-soluble fluoride was reduced to 7.94 mg/L,and the pH was 8.5,which reached the discharge standard of"Class Ⅰ general industrial solid waste".The research results can provide reference for the effective treatment and disposal of phospho-rus tailings and phosphogypsum.