Expand Experimentation Study On Extracting Gallium From Fly Ash By The Method Of Separation And Enrichment With Polyurethane Foam

Gallium is a kind of dissipated metal,It is mainly associated in the waste residue of the bauxite and lead-zinc ore,and the content is quite low.At present,the separate recovery of gallium with solvent extraction is the mainly used method.However,the efficiency of this method is quite low and it is easy to cause pollution for the dose of solvent is too high in the extraction process,so it is very significant to find a new efficient,low cost and eco-friendly gallium recovery method.Fly ash contains about 12-230?g/g of gallium.In order to make full use of the waste resource,protect the environment and improve economic returns,this research mainly discussed separating gallium from the coal ash and its large-scale industrial use.This research is based on the fact that a mass of carbonyls and amidogens exist in the polyurethane foaming plastic,so the foaming plastic can absorb the gallium chloride acid in two ways:polar adsorption and intermolecular forces adsorption,and in the hydrochloric acid solution,there turns to be two chemical adsorption ways:ion association and chelation.In this experiment,the polyurethane foam plastic was used to adsorb the gallium ion,the adsorption and elution condition was studied.The influencing factors were studied in the polyurethane foam plastics adsorption of gallium solution by single factor experiment and orthogonal experiment,finally the optimal technological conditions of gallium adsorption and elution was obtained:in a concentration of 6mol·L-1 hydrochloric acid solution,keep the polyurethane foam plastics oscillation for 2h to the adsorption equilibrium under room temperature,the adsorption rate can reach to more than 90%;put the gallium adsorption polyurethane foam plastic in a concentration of 0.5mol·L-1 NH4C1 solution,keep the oscillation for 60 min under room temperature,to achieve the best elution effect,and the interfering ion has little effect ont this process,the foam plastic regeneration can be repeatedly used after washing.Taking the fly ash as raw materials,go through the process of preliminary desilication,clinker digestion and mention aluminum,then the aluminum liquid waste will be on carbon points,precipitation acid soluble polyurethane foam adsorption and elution.After aerating CO2 for 26 minutes,the gallium ions concentration in the solution remains unchanged.At this point,the solution pH is 9.71,the gallium ions concentration in the solution is 0.87?g/mL,the deposition rate of gallium ions in the solution is 86.12%,and the recovery of gallium in the sample is 77.56%,achieving a good recovery effect.This study provides an important basis for the comprehensive utilization of coal ash and gallium extraction.