Dissertation > Excellent graduate degree dissertation topics show

A Novel Method for the Vanadium Extraction from Stone Coal

Author: YangKang
Tutor: TianXueDa
School: Xiangtan University
Course: Environmental Engineering
Keywords: Bone coal Vanadium Vanadium pentoxide Vanadium Extraction Fluosilicic
CLC: TF841.3
Type: Master's thesis
Year: 2010
Downloads: 244
Quote: 0
Read: Download Dissertation

Abstract

Vanadium is a rare and refractory metals, has important strategic significance. Of vanadium and vanadium products mainly come from the stone coal, however, the traditional stone coal vanadium extraction process due to the existence of a number of deficiencies and limited to its promotion and application of stone coal vanadium extraction process has always been a hot research topic. In this paper, fluosilicic acid as the leaching agent / assistant infusion stone coal direct acid leaching vanadium, and Shen vanadium in oxidation process using hydrogen peroxide instead of the traditional craft oxidant sodium chlorate, the entire process to avoid the toxic and harmful gas emissions. problems. In order to determine the degree of application of the fluosilicic acid leaching process, the leaching experiments were carried out on two different sources of stone coal (from Guizhou and Gansu), the follow-up process research and stone coal mine in Guizhou the fluosilicic acid sulfate leaching system leaching solution . The leaching stage experimental results show that the best conditions Guizhou stone coal sulfuric acid leaching: 30% of the amount of sulfuric acid leaching temperature of 95 ° C, leaching time 24h leaching solution to solid ratio of 1:1, the the V2O5 leaching rate 68%; fluorosilicone acid leaching of the best conditions: 20% of the amount of fluosilicic leaching temperature of 95 ° C, leaching time 8h, lixivium, solid ratio 1:1, the the V2O5 leaching rate reached 80%. Gansu stone coal sulfuric acid leaching conditions: 30% of the amount of sulfuric acid leaching temperature of 95 ° C, leaching time 24h leaching solution to solid ratio of 1:1, the the V2O5 leaching rate of 40%; fluosilicic acid leaching : the fluosilicic use 30%, the leaching temperature of 95 ° C, leaching time 12h leaching solution to solid ratio of 1:1, the rate of V2O5 leaching reached 60%. Stone coal in Guizhou mixed acid leaching of the best conditions: 8% fluosilicic acid in 15% sulfuric acid, leaching time 12h, leaching temperature 95 ° C leaching solution to solid ratio of 1:1, the the V2O5 leaching rate can reach about 80%. Gansu stone coal mixed acid leaching conditions: 15% sulfuric acid 8% fluosilicic acid leaching time 16h, leaching temperature of 95 ° C, the leaching liquid to solid ratio of 1:1, the the V2O5 leaching rate can reach 55 percent. Stage of the separation and concentration of vanadium experimental results show that the optimum conditions for the extraction: the extraction system 10% P204 5% TBP 85% sulfonated kerosene and Crafts dope pH = 3.0, contact time 5min, O / A = 1: 1, extraction temperature 30 ° C, the single-stage extraction rate of stone coal the fluosilicic acid sulfate leaching solution at this time more than 60%; 7 after extraction, the extraction rate of 99%. The back extraction optimum conditions: the mass fraction of 10% sulfuric acid in the stripping agent, contact time 10min, O / A = 10:1, this time V2O5 stripping rate reached more than 70%; 5 stripping, V2O5 anti extraction rate ≥ 99%. Shen vanadium and vanadium preparation phase of the experiment results show that the As oxidation NaClO3 kind Shen vanadium was 95%, pH = 2, Shen vanadium temperature of 95 ° C, of ??V2O5 time 2h conditions; samples by H2O2 in pH = 4, the Shen vanadium temperature of 95 ° C, Shen vanadium 5h conditions, the rate of Shen vanadium can reach 95%. Under these conditions settle down the pyrolysis of vanadium products for testing, results are up to the the 98 V2O5 standards of the National vanadium products. The existing mineral acid dissolution mechanism Qualitative Stone Coal Leaching Mechanism fluosilicic role. Solution of fluosilicic first decomposed in acidic solution generating HF, the cation in the stability of the mineral lattice structure immediately in acidic conditions HF ionization of the role of the F-elution according to the following three steps: nF-... nH M -Az? nF-... nH? M-Az nF-... nH? M-Az? nF-... Az? M-nH nF-... Az? M-nH? AFn M-nH which, F-played accelerated mineral cationic eluted role.

Related Dissertations

CLC: > Industrial Technology > Metallurgical Industry > Nonferrous metal smelting > Rare metal smelting > Refractory metals smelting ( high - temperature molten metal ) > Vanadium
© 2012 www.DissertationTopic.Net Mobile