With the increasing scarcity of global phosphate ore resources and the promotion of green, low-carbon and environmental protection policies, efficient development and utilization of phosphate ore resources has become an inevitable trend. This article focuses on the characteristics of a weathered phosphate ore and develops a combined scrubbing flotation process through systematic process research. It effectively improves the P2O5 grade of the phosphate ore, reduces the content of MgO and SiO2, and meets the production requirements of downstream chemical enterprises.
Phosphate ore, as an important chemical raw material, is widely used in agricultural production and industrial manufacturing. As the world's second-largest phosphate ore resource country, China's level of development and utilization is directly related to the sustainable development of the national chemical industry. The Yunnan region has abundant weathered phosphate ore resources, but due to the influence of ore properties, traditional beneficiation methods are unable to meet the production needs of high efficiency and high purity. Therefore, exploring new mineral processing technologies is of great significance.
The chemical composition analysis of the weathered phosphate ore shows that the mass fractions of P2O5, MgO, and SiO2 are 23.52%, 1.00%, and 26.18%, respectively. According to the DZ/T 0209-2002 standard, the ore sample belongs to siliceous and silicate type phosphate rock ore. It is necessary to remove most of the siliceous and silicate minerals through beneficiation process to enrich phosphate minerals.
A combined scrubbing flotation process has been developed for the characteristics of weathered phosphate ore. Firstly, coarse-grained ore is directly treated as finished ore through classification, while fine-grained ore is enriched by flotation and combined with coarse-grained minerals to form the total concentrate. This process not only simplifies the process, but also reduces the consumption of chemicals.
(1) Grinding fineness test
Research has shown that when the grinding fineness reaches 91.0%, the grade of P2O5 concentrate reaches a higher level, therefore the grinding fineness is determined to be 91.0%.
(2) Technical route determination
Based on the particle size screening results of the ore sample, the classification flotation process flow was determined. Among them, particles larger than 0.038mm are prioritized for separation as qualified products, and particles smaller than or equal to 0.038mm are used as flotation selected raw materials.
(3) Drug dosage test
The effect of different dosages of Na2CO3, Na2SiO3, dispersant, and collector YP2-1 on the P2O5 grade of phosphate concentrate was studied using a single factor method, and the optimal dosages of various reagents were determined.
The results of open circuit and closed circuit tests showed that after the combined process of scrubbing flotation, the grade of P2O5 in the raw ore increased from 23.99% to 28.07%, the grade of MgO decreased from 0.98% to 0.85%, and the grade of SiO2 decreased from 27.15% to 19.65%, effectively meeting the quality requirements of downstream chemical enterprises.
The application of a combined scrubbing flotation process in a weathered phosphate mine in Yunnan has significantly improved the P2O5 grade and reduced impurity content, providing technical support for the efficient development and utilization of phosphate resources. The optimization of the process flow and precise control of the dosage of reagents provide important reference value for the beneficiation of similar weathered phosphate ores.
