Vanadium extraction equipment and technological process of parsing - — Extraction of zhengzhou
the world metal vanadium production cost is high, the output is small, main extraction methods: roasting method and wet method to extract. Over the years, the extraction of vanadium pentoxide, the main method of sodium roasting - Water and dilute acid leaching - Heavy vanadium ammonium process, low recovery rate of vanadium pentoxide, and produce HCl, Cl2 gas, serious environmental pollution. Zhengzhou extraction company as domestic hydrometallurgy extraction equipment manufacturers, wet method for vanadium extraction equipment technology and rich experience.
zhengzhou extracting vanadium extraction processes are mainly: the first classification scrubbing technology is adopted to improve the separation enrichment, grade 2. 50% of the vanadium ore concentrate; Then using two counter-current acid leaching - Neutralizing - Reduction - Solvent extraction - Ammonium salt heavy pure wet processes of vanadium extracting V2O5.
the vanadium ore mainly ( Ⅲ) Form and six coordination of trivalent aluminium show class exists in mica crystal lattice with like, mica formula for K ( Al,V) 2 ( 哦) 2AlSi3O10。
the vanadium extraction from the mica to destroy the structure of mica, under a certain temperature and acidity, hydrogen ions into the replacement of Al3 + in the mica, make the change ionic radius, which release vanadium by acid dissolution and oxidation into a high price.
P204 of tetravalent vanadium has high selectivity, and extracting Fe3 + and not Fe2 +, so before extraction should be to restore the leach liquor, make all exist in the form of tetravalent vanadium, and control the REDOX potential, Fe3 + reduction into Fe2 +.
two counter-current extraction of leachate, V2O5 mass concentration 6 ~. 5 g/L, Fe2 + 15 g/L mass concentration, impurities such as aluminum and potassium content is higher, also need to the neutralization and restore to remove impurities.
with ammonium bicarbonate and, make the solution pH in 1. 73-1. Between 76, deposited thick aluminum sulfate, potassium sulfate and ammonium salt of a mixture, then the neutralization liquid after adding suitable amount of iron powder pentavalent vanadium reduction into tetravalent vanadium, and controls the solution pH in 2. 0 ~ 2. Between 30, REDOX potential in + 50 ~ - Between 50 mV.
in the process of neutralization, reduction V2O5 loss rate is less than 3%.
3, solvent extraction and reverse extraction
after neutralizing reduction solution ( Extraction concentrate) Impurity content is less, rho ( V2O5) For 3 ~ 6 g/L, rho ( Fe2+) For 12 ~ 14 g/L, pH = 2. 20
under normal temperature, with P204 + 10% 15% the TBP + 75% sulfonated kerosene as extractant, organic facies control the flow of water phase ratio between 1:1 and 1:2, counter-current extraction vanadium on level 5.
loaded organic phase with 1. 5 mol/L sulfuric acid solution at room temperature for 5 levels of countercurrent extraction, the results can be seen that the extract of V2O5 mass concentration is higher, the extraction more completely.
extraction and reverse extraction equipment at present mainly include extraction tank and new centrifugal extraction equipment, introduced. cwl - zhengzhou extraction M series centrifugal extraction machine is developed aiming at the disadvantages of traditional centrifugal extraction machine, the fourth generation of products with independent intellectual property rights and patent number: ZL2014205865573, the centrifugal extraction machine has saved the time is short, split phase quickly, the advantages of high extraction efficiency, save the investment cost.
4, precipitation by ammonium salt precipitation method to extract vanadium
vanadium containing the extract of vanadium is tetravalent, before the precipitation to be oxidized to five. In a mass concentration of 200 g/L sodium chlorate solution as oxidant, stir for 1 h under 60 ℃, REDOX potential in - control 900 - - Between 1200 mv.
in ammonia water solution pH value is 2. Stir about 0, 92 3 h, precipitation of ammonium vanadate ( Red vanadium) , precipitation rate for 97. 72%. Precipitation in the mother liquor, V2O5) = 0. 26 ~ 0. 38 g/L, return to leaching.
5, waste water treatment
to give priority to in order to extract residual liquid with lime neutralization of acid waste water treatment. Sewage in the main harmful impurities containing Fe and Al, As, Cd, etc. , when the pH> 7, iron, aluminum and other impurities in the form of hydroxide precipitation, sulfuric acid root in the form of calcium sulfate precipitation. Because the iron hydroxide and aluminum hydroxide are good loading agent, in the process of precipitation can be loaded with other harmful elements, so fully purify sewage.
waste water after treatment to reach GB8978 - 1996 emissions standards, use part of the return process, the rest of the outside.