Extraction of Metal Arsenic from Waste Sodium Arsenate by Roasting with Charcoal Powder

Abstract

Abstract:The current paper explored the directly reductive decomposition of waste sodium arsenate by roasting it with charcoal powder to volatilize less toxic As 0 and to simultaneously obtain sodium salts with potential commercial value, serving the purpose of developing a more sustainable route to deal with the environmental issues faced by the antimony production industry in China. The process was firstly evaluated by thermogravimetric (TG) analysis and thermochemical calculations. The effects of N 2 flow rate, roasting temperature, dosage of charcoal powder, and roasting time were then investigated. The results showed that the arsenic extraction could reach 99.84% under optimal conditions. The roasting residue, containing arsenic as low as 0.0598%, was a promising source for the production of Na 2 CO 3 as expected. In addition, X-ray diffraction (XRD), scanning electron micrograph (SEM), and X-ray photoelectron spectroscopy (XPS) were conducted to reveal the roasting mechanism and formation of metal arsenic was thereby confirmed.

Polymeric organogel as an effective approach for eradication of heavy metal ions As, Pb, Cd, and Cr from the surface of groundwater through adsorption stratagem

“…While binding energies at 394.62, 398.15, and 400.86 eV of N1s attributes to CNH, CNC, N(CO) 32 . The binding energy of arsenic being observed at 43.50 eV experienced a slight shifting from its original binding energy of 44.7eV 33 . This confirms the interaction of the metal with the organogel on its active surface.…”

“…32 The binding energy of arsenic being observed at 43.50 eV experienced a slight shifting from its original binding energy of 44.7eV. 33 This confirms the interaction of the metal with the organogel on its active surface. Similar conclusions can thus be drawn for the other heavy metals.…”

Application of Chemically Modified Industrial Slag to As(III) Adsorption from Wastewater: Kinetics and Mass Transfer Analysis

“…At alkaline pH, the dominating negatively charged species are formed resulting in electrostatic repulsion between the negatively charged surface of the adsorbent and the negatively charged As(III) ions thereby reducing the relative uptake capacity of As(III) ions at alkaline pH. 23 Under optimised condition of pH (~7.0), As(III) ions are capable of binding with the sulphate ions on Scheme 1. Schematic representation of the proposed mechanism for As(III) ions adsorption using acid and alkali modified industrial slag at pH = 7.0 and temperature = 298 K the surface of the acid modified slag releasing a water molecule as a by-product while arsenate ions can bind with the hydrogen ions forming weak arsenious acid.…”

“…The Freundlich isotherm is represented in Eq. ( 23): (23) where k f and n are Freundlich constants. The extent of feasibility of the adsorption of As(III) ions can be determined from the value of n. For a favourable process, (1/n) < 1.…”

Green Route to Arsenic Detoxification: Mechanochemical Transformation of As2O3 to As(0)

“…According to previous reports, , the reduction of elemental arsenic from arsenate, arsenic oxides, and arsenic-bearing wastes has been extensively investigated. Various technologies have been explored, including thermal reduction, , liquid-phase reduction, and electrochemical conversion .…”