Study On Extraction Of Rubidium From Biotite Of Granite

With the rapid development of today’s high technology and its applications,rubidium based on its special nature have begun to be applied to a wide range of keytechnologies in aerospace, medical equipment, electronic information, new energydevelopment and so on. It also has become an important element of sophisticatedtechnological development, its application shows a perfect future.Rubidium has been not found in any independent minerals until now, it is oftenassociated with other alkali metals, its extraction and more researches have beenreported, but rarely found extraction of rubidium relating biotite. The paper on rawmaterials used in rubidium extraction process are granite from Inner Mongolia region,studied the magnetic selected from biotite of granite, and the entire process frombiotite decomposition method to the final extraction and separation of rubidium, thispaper in order to further enhance the development of mineral resources of graniteadded value, and provide technology as reference.By granite mineral composition and chemical analysis, biotite has a high value inindustrial use for the extraction of rubidium, the biotite can be sorted with other majormineral by magnetic sorting.By polarized light microscopy to understand thecharacteristics of granite, from granularity statistical analysis learned that the mainlybiotite granularity is0.074~0.5mm, the average particle size is0.32mm.In experiments on biotite magnetic separation from granite, the present paperdiscussed the effects of magnetic field strength，the separation number and ore particlesize on magnetic separation results. The optimal magnetic separation conditions are:magnetic materials particle size should be from-40mesh to+180mesh and not toobig or too small. About the raw materials from-40mesh to+60, the best magneticfield strength is666.5kA/m, and the separation number is3；about the raw materialsfrom-60mesh to+180mesh，the best magnetic field strength is533.2kA/m and theseparation number is3，each time after the mineral magnetic selection to beperformed twice. Biotite recovery was54.74%. In the experiment of biotite decomposition，three methods of sulfate roasting,direct acid leaching and calcium chloride roasting were studied. Experimental resultssuggest that: due to higher baking temperatures and the formation of silicate salthampered rubidium leaching, the leaching rate of rubidium only about70%; directacid leaching method, due to the structure of biotite cannot be completely damaged,rubidium leaching rate is only about80%; while roasting method in calcium chloride,rubidium leaching rate up to90%,the results of the third method are stability andrepeatability, and finally the calcium chloride roasting method as the best method ofbiotite decomposition. The optimal conditions is0.6times the mass of biotite at850℃CaCl2insulation20min, biotite rubidium leaching rate of97.3%.Depending the extraction ability of extraction solvent on the alkali metal element,prior to extraction of rubidium, cesium should be firstly isolated by extraction, thebest extraction of cesium, rubidium is O/A=1:1, and then the best extraction ofpotassium, rubidium is O/A=3:1, the O/A of elution is4:1, followed with1mol/Lhydrochloric acid for stripping, the O/A of stripping is1:1. Single-stage extractionexperiments, the extraction rate is low, through using of multi-stage extractionexperiments can effectively improve the extraction rate of rubidium, in a multi-stageextraction experiments, the extraction rate of rubidium was93.19%, the purity ofthe RbCl sample was99.04%.From raw materials to the final sample, total recovery of rubidium is49.63%.