silver recovery using sodium sulphide

After 60 min, silver recovery started to decrease to different extent with different sodium sulfite concentrations. For 0.1 M sodium sulfite, silver recovery decreased significantly from 43% (60 min) to 3% (300 min). As a comparison, for 1.19 M …

precipitation of copper and silver in a serpentine reactor, using sodium sulfide as the precipitator, and sulfuric acid for pH control. 2. Cyanide and Copper Recovery Processes . Sulphide precipitation of metals is a viable alternative process for copper recovery from the barren cyanide so- lutions because of the possible high degree of metal re-

Key advantages of this approach would be 1) elimination of chemical dosing for sulfide oxidation and thus, less operational, transport, handling and storage cost of potentially hazardous chemicals, which reduces occupational health and safety concerns, 2) recovery of sodium and oxidized sulfur species that can be re-used in situ or be sold, 3 ...

Introduction. Silver sulphide (Ag 2 S) is a very stable silver compound, which is not readily dissolved using mineral acids under atmospheric conditions. Because of its low solubility, several processes for the recovery of silver from photographic solutions use sulphidizing agents, such as sodium sulphide (Na 2 S) or sodium hydrosulphide …

Basically, refractory gold ores (gold recovery efficiency of <50% in average using direct cyanidation) are classified into sulfide, tellurium and carbon ores. Sulfide gold ores account for a large proportion of refractory gold ores, therefore, it is very meaningful to recover gold from sulfide gold ores ( Ubaldini and Vegliò, 2000, Saba, 2011 ...

In a recent study, Koc et al. (2016) investigated the precipitation of silver as sulphide using sodium sulphide (2.0-24.2 ... Recovery of silver from cyanide leach solutions by precipitation using ...

Lead was extracted using brine solution as the leachant. The maximum leaching efficiency of 80.66% was obtained using 35% brine solution under the conditions of 5% pulp density, 90 °C temperature and 1 h duration. Lead was further recovered from the brine leach solution as lead sulphide using sodium sulphide by precipitation …

The low degree of precipitation 40,35% using sodium sulfide solution suggests it is hardly possible recovery route for silver from acidic thiourea leach …

In a recent study, Koc et al. (2016) investigated the precipitation of silver as sulphide using sodium sulphide (2.0–24.2 mM Na 2 S) from a PLS derived from the …

Very few are based on thiosulfate media [Na 2 S 2 O 3 2 −] for silver recovery, particularly in the treatment of tailings in Hidalgo State ... Study of thiosulfate leaching of silver sulfide in the presence of EDTA and sodium citrate. Effect of NaOH and NH 4 OH. Hydrometallurgy, 149 (2014), pp. 1-11. View PDF View article View in Scopus ...

The percentage recovery of the dissolved silver obtained from the refractory ore was 57.64% at 90 °C before the untreated pressure oxidation (ambient leaching), while the recovery has been increased by about 5% and reached 62.35% at 150 °C when applying the pressure leaching method by using an autoclave.

Recovery of silver from real pregnant leach solutions using sodium borohydride (NaBH 4) as the precipitating agent was also investigated in detail. A high silver recovery of ≥98% was achieved under suitable conditions. ... Leaching behavior of silver sulfide in the sodium thiosulfate-copper sulfate- sodium metabisulfite system. …

Figure2shows the Eh-pH diagram of hydrolysis speciation of sulphide and sulphate. The presence of hydrogen sulphide (HS) in the solution is pH dependent, occurring between pH 7–13. Hydrogen sulphide is a highly water-soluble gas (4–6 g/L) and can exist in solution in three di erent forms (i.e., H2S, HS, or S2) depending on the Eh-pH ...

The precipitation of metal sulfides can be carried out using a variety of precipitants, such as sodium sulfide (Na 2 S), sodium hydrosulfide (NaHS), calcium sulfide (CaS), barium sulfide (BaS), iron sulfide (FeS), ammonium sulfide ((NH 4) 2 S), and sodium thiosulfate (Na 2 S 2 O 3) (Lewis 2010; Mokone et al. 2012; Thomas et al. …

In the leaching process, due to the small stable constant of Ag (SO 3) 2 3 − which was measured to be 7.9 (Baltrunas et al., 2008) and readily oxidizing sulfite by oxygen dissolved in aqueous solution, a high concentration of sodium sulfite is inevitably implemented for the silver recovery, consequently, leading to a high consumption …

This already suggests an increase in the exposed active surface area of CuS for facile sodium insertion/extraction and well reflects the decrease of R ct, which results in the capacity recovery. Coulombic efficiency over both at 0.2 C and 3 C during the capacity recovery implies increasing extraction of sodium, which is originally confined ...

Furthermore, the use of biogenic H 2 S instead of chemical sulfide salts such as Na 2 S and NaHS avoids the need for addition of acid, as sodium sulfide salts are very basic, and prevents the ...

The present research reports a simple and efficient method for silver recovery using sodium hydroxide and sodium sulfide from the waste x-ray film. …

Fink and Putnam (1950) found that the addition of trace amounts of sodium sulphide to the cyanide solution dramatically hindered gold leaching, and postulated that the sulphide ions passivate the ...

Silver may be recovered from photography trash using Sodium sulphide as re-using the resulting solution becomes challenging in photography. ... Na 2 S is used with surfactants to clean up aquifers polluted with nonaqueous phase liquids for oil recovery. Conclusion. Sodium sulfide (Na 2 S) is applied in various fields, including water …

Silver Recovery from X-ray Film Waste by Leaching and Precipitation Method Using Sodium Hydroxide and Sodium Sulfide Soja Siti Fatimah *, Wiwi Siswaningsih, Ali Kusrijadi, Fikri Aziz Shalahuddin

The speciation calculations using MEDUSA (2009) software revealed that under the experimental conditions tested in this study, the dominant silver complex is Ag(S 2 O 3 ) 3 5− (Fig. 6) Under low ...

Basically, refractory gold ores (gold recovery efficiency of <50% in average using direct cyanidation) are classified into sulfide, tellurium and carbon ores. Sulfide gold ores account for a large proportion of refractory gold ores, therefore, it is very meaningful to recover gold from sulfide gold ores (Ubaldini and Vegliò, 2000, Saba, 2011 ...

Meanwhile, the use of Ar gas prevents the silver from redissolution in the fixing solution. In the current method, it should be noted that the use of highly acidic pH levels degrades …

E-mail: anu3480@gmail, Received 30 September 2016; accepted 14 July 2018. A novel, simple, fast, cheap and pollution free method for utilizing waste X-ray film for silver recovery using sodium hydroxide and sodium sulfide by the stripping and precipitation processes, respectively has been reported.

The initial sodium sulphide elution trial was conducted using 20 g of carbon and 2 L of solution, the ammonium chloride elution involved 50 g of carbon and 2 L of solution with remaining experiments being conducted using 25 g of carbon and 1 L of solution. 50 ml samples were taken periodically, from the elution trials with the volume of liquid ...

The pH must be maintained between 8.5 and 10 using soda ash. Frothers as glycol esters and cyclic alcohols (pine oil) are used ongoingly to enhance gold recovery. Sodium silicate starch dextrins can be added as gangue depressant. Gold-containing Mercury/Antimony

novel method for recovering high-purity silver from waste x-ray films using sodium hydroxide. The research also focuses on the optimization of the parameters that affect …

Recovery of silver from real pregnant leach solutions using sodium borohydride (NaBH4) as the precipitating agent was also investigated in detail. A high silver recovery of ≥98% was achieved ...

Finally, silver was recovered by precipitation using sodium sulphide. The yield or recovery was then determined using XRF. A maximum silver recovery of 54% w/w …

Silver and tellurium are crucial valuable metallic elements in anode slimes. During pyrometallurgical processing, tellurium exists in the alloy as the stable compound Ag 2 Te. The current process of separating tellurium from silver-tellurium compounds in crude silver by oxidizing tellurium into slag leads to undesirable loss of silver, low recovery …

Results show that pH value has a significant effect on copper cyanide removal efficiency, and it was determined the optimal pH range to be 2.5 -3. At this pH value, the copper cyanide removal ...

The resulting silver sulphide is reduced to a metallic slime by the Denny desulphurizing process which incidentally regenerates most of the sodium sulphide used in precipitation. PRECIPITATION of GOLD ON CHARCOAL. T.P. 378, U.S.B. of M, 1927, by John Gross and J. W. Scott, is a most comprehensive publication on the use of …

In a recent study, Koc et al. (2016) investigated the precipitation of silver as sulphide using sodium sulphide (2.0-24.2 mM Na 2 S) from a PLS derived from the cyanide leaching of a pyritic gold ...

Sahinkaya et al. (2009) focussed on selective recovery of metals (at 50–100 mg/L) from acid mine drainage using biogenic sulphide. Cu was successfully precipitated at pH < 2 using sulphide transported from the biological reactor using N 2 gas. Zn did not precipitate during Cu removal but was 84–98% removed in a separate reactor that used ...