Experimental Study On Improving Quality And Reducing Impurity Of Fluorite In Baiyun Obo Rare Earth Tailings

Fluorite is a very important non-metallic mineral resource and a major source of fluorine in fluorine chemical products.It is also widely used in the metallurgical and ceramic industries.China has now become the country with the largest consumption of fluorite in the world.Although China has a large reserve of fluorite resources,there are more single-type fluorite deposits,and the reserves are relatively small.The resources associated with ore are very large.In order to get rid of the plight of fluorite resources,it is necessary to develop and utilize fluorite resources in associated mines.The reserves of fluorite resources associated with the Baiyun Obo Mine are huge,accounting for about half of the total fluorite resources in China.This paper is a study on the utilization of fluorite resources in the Baiyun Obo Mine.According to the process mineralogy of the Baiyun Obo rare earth tailings,the grade of fluorite in rare earth tailings is 26.6%,and the minerals affecting fluorite flotation have iron mineral content as high as 17.4%,silicate mineral neonite and sodium.The total content of amphibole and biotite is 19.9%,the content of carbonate mineral dolomite and calcite is 15.7%,and the content of rare earth mineral is 3.9%.The monomer dissociation degree of fluorite minerals is 76.50%.The fluorite minerals are closely associated with iron minerals,carbonate minerals,silicate minerals and rare earth minerals.Fluorite and hematite and bastnasite are present.Adjacent,invasive symbiosis,in addition to a small amount of symbiosis with magnetite.In this paper,a two-stage flotation test is used.In the case of a flotation test,the amount of sodium oleate in the collector is 400g/t,the amount of water glass for the inhibitor is 1200g/t,and the amount of HY-1 is 200g/t.Under the condition of pH value 8,the"one coarse and three fine"flotation process was used for the closed circuit test.A high-grade fluorite concentrate with a concentrate CaF₂ grade of 82.95%and a CaF₂recovery of 80.95%can be obtained.For a section of flotation concentrate,the grinding fineness reaches-25μm and the content reaches 82.40%,then the second stage of beneficiation is carried out.The second stage of ore dressing is 140g/t of sodium sulpHate in the collector,and the amount of water glass of the inhibitor is 387g/t.The dosage of HY-1 was 134g/t,the pH value of flotation pulp was 8,and after flotation,under the condition of strong magnetic strength under the intensity of 14000 Gauss,the process of“one coarse and one fine magnetic strengthening”was selected for the beneficiation test.Finally,the fluorite concentrate with a concentrate CaF₂ grade of 95.32%and a CaF₂recovery of 44.18%has been obtained,which has reached the industrial chemical grade fluorite concentrate grade.The study on the dissolution characteristics of the mineral surface shows that when the pH of the aqueous solution is alkaline,the localized electrons on the surface of the pure mineral of fluorite are mainly H⁺and OH^-,which is not conducive to the electrostatic adsorption of the surface of the anion collector and the fluorite mineral.Therefore,under alkaline conditions,the surface action of anionic collector and fluorite mineral is mainly chemisorption.By detecting the zeta potential of fluorite pure mineral before and after the action of sodium oleate,it can be found that the zero potential of fluorite pure mineral is about 6.88.When the pH value is greater than 6.88,the surface of fluorite mineral is negatively charged.After the action of sodium and fluorite pure minerals,the surface of fluorite minerals is negatively charged and the absolute value increases greatly,which indicates that the surface of sodium oleate and fluorite pure minerals have been chemisorbed.The fluorite minerals of fluorite pure mineral,sodium oleate and sodium oleate were detected by Fourier transform infrared spectroscopy.The analysis of infrared spectrum showed that the adsorption of sodium oleate on the surface of fluorite pure mineral was chemical adsorption.