摘要
There exists the most important REE-bearing phosphorite deposit in Southwest of China. Due to the fact that the REE are present in the form of ions in the lattices of collophanite or carbonatfluorapatite, the REE can be enriched in phosphate concentrate by flotation method. The phosphate concentrate is the main raw materials to produce phosphoric acid, therefore, it is significant to further investigate the distribution rule of REE in wet process. In this paper, the single leaching and recycled leaching technology were carried out to investigate the effect of various parameter conditions on distribution of REE in products. The REE compositions of products were analyzed by Inductively Coupled Plasma Emission Mass Spectrometry (ICP-MS) method. It was found that the acidic value of leaching liquor was the main effect factor on the distribution of REE in products. In single leaching stage, P2O5 concentration of leaching liquor slightly varied from 8% to about 10% when the excessive coefficient of sulphuric acid ranged from 1.03 to 1.05, and the distribution proportions of ∑REO in phosphoric acid solution was lower than 40%. However, in recycled leaching process(the condition similar to practical wet process), with an increase of P2O5 concentration as well as the acidic value of leaching liquor, the distribution proportions of ∑REO in phosphoric acid solution could be decreased to 2.56%. That is to say that under the condition similar to practical wet process, more than 90% of REE of phosphate concentrate became precipitation entering into the phosphogypsum product. This investigation will provide valid reference for reasonably recovering or reserving REE in wet-phosphoric acid process.
There exists the most important REE-bearing phosphorite deposit in Southwest of China. Due to the fact that the REE are present in the form of ions in the lattices of collophanite or carbonatfluorapatite, the REE can be enriched in phosphate concentrate by flotation method. The phosphate concentrate is the main raw materials to produce phosphoric acid, therefore, it is significant to further investigate the distribution rule of REE in wet process. In this paper, the single leaching and recycled leaching technology were carried out to investigate the effect of various parameter conditions on distribution of REE in products. The REE compositions of products were analyzed by Inductively Coupled Plasma Emission Mass Spectrometry (ICP-MS) method. It was found that the acidic value of leaching liquor was the main effect factor on the distribution of REE in products. In single leaching stage, P2O5 concentration of leaching liquor slightly varied from 8% to about 10% when the excessive coefficient of sulphuric acid ranged from 1.03 to 1.05, and the distribution proportions of ∑REO in phosphoric acid solution was lower than 40%. However, in recycled leaching process(the condition similar to practical wet process), with an increase of P2O5 concentration as well as the acidic value of leaching liquor, the distribution proportions of ∑REO in phosphoric acid solution could be decreased to 2.56%. That is to say that under the condition similar to practical wet process, more than 90% of REE of phosphate concentrate became precipitation entering into the phosphogypsum product. This investigation will provide valid reference for reasonably recovering or reserving REE in wet-phosphoric acid process.
基金
the Natural Science Foundation of Guizhou Province (QianKeHe J[2005]2098)
