scholarly journals Deposition of Arsenic from Nitric Acid Leaching Solutions of Gold–Arsenic Sulphide Concentrates

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 889
Author(s):  
Kirill Karimov ◽  
Denis Rogozhnikov ◽  
Evgeniy Kuzas ◽  
Oleg Dizer ◽  
Dmitry Golovkin ◽  
...  

At present, the processing of refractory gold–arsenic sulphide concentrates is becoming more relevant due to the depletion of rich crude ore reserves. In the process of the nitric acid leaching of arsenic sulphide minerals, solutions are formed containing 20–30 g/L of arsenic (III). Since market demand for arsenic compounds is limited, such solutions are traditionally converted into poorly soluble compounds. This paper describes the investigation of precipitating arsenic sulphide from nitric acid leaching solutions of refractory sulphide raw materials of nonferrous metals containing iron (III) ions using sodium hydrosulphide with a molar ratio of NaHS/As = 2.4–2.6, which is typical for pure model solutions without oxidants. The work studied the effect of temperature, the pH of the solution and the consumption of NaHS and seed crystal on this process. The highest degree of precipitation of arsenic (III) sulphide (95–99%) from nitric acid leaching solutions containing iron (III) ions without seed occurs with a pH from 1.8 to 2.0 and a NaHS/As molar ratio of 2.8. The introduction of seed crystal significantly improves the precipitation of arsenic (III) sulphide. An increase in seed crystal consumption from 0 to 34 g/L in solution promotes an increase in the degree of transition of arsenic to sediment from 36.2 to 98.1% at pH = 1. According to SEM/EDS and XRF sediment data, from the results of experiments on the effect of As2S3 seed crystal consumption, acidity and molar ratio of NaHS/As on the precipitation of arsenic (III) sulphide and the Fetotal/Fe2+ ratio in the final solution, it can be concluded that the addition of a seed accelerates the crystallisation of arsenic (III) sulphide by increasing the number of crystallisation centres; as a result, the deposition rate of As2S3 becomes higher. Since the oxidation rate of sulphide ions to elemental sulphur by iron (III) ions does not change significantly, the molar ratio of NaHS/As can be reduced to 2.25 to obtain a precipitate having a lower amount of elemental sulphur and a high arsenic content similar to that precipitated from pure model solutions.

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1250 ◽  
Author(s):  
Bo Liu ◽  
Shengen Zhang ◽  
Britt-Marie Steenari ◽  
Christian Ekberg

This paper proposes a new method for producing nano-SrFe12O19 powder by the citrate precursor route using solid waste as a source of iron. This solid iron-containing waste, which exists in the form of an oily sludge, is produced by a cold rolling mill. This sludge was first subjected to a process, including sulfuric acid leaching, oxidation, precipitation, and nitric acid leaching, to obtain an iron nitrate (Fe(NO3)3) solution. Next, the Fe(NO3)3 solution was mixed with a strontium nitrate (Sr(NO3)2) solution obtained by subjecting strontium carbonate to nitric acid leaching. Subsequently, citric acid, as chelating agent, and ammonia water, as precipitating agent, were added to the mixed solution to form a gel. The gel was dried and spontaneously combusted, then annealed at different temperatures for 2 h in flowing air. The effects of the Fe3+/Sr2+ molar ratio and annealing temperature on the formation, morphology, and magnetic properties of SrFe12O19 were investigated. The results showed that single-phase SrFe12O19 powder was obtained by decreasing the Fe3+/Sr2+ molar ratio from the stoichiometric value of 12 to 11.6 and increasing the annealing temperature to 1000 °C for 2 h. Adjustment of the Fe/Sr molar ratio to 12 and the annealing temperature to 900 °C enabled the magnetic properties to be optimized, including saturation magnetization (Ms) 80.2 emu/g, remanence magnetization (Mr) 39.8 emu/g, and coercive force (Hc) 6318 Oe.


2013 ◽  
Vol 54 (6) ◽  
pp. 440-442 ◽  
Author(s):  
D. A. Rogozhnikov ◽  
S. V. Mamyachenkov ◽  
S. V. Karelov ◽  
O. S. Anisimova

2017 ◽  
Vol 2 (2) ◽  
pp. 174
Author(s):  
Rogozhnikov D.A. ◽  
Dizer O.A. ◽  
Shoppert A.A.

<p>Thermodynamic and kinetic features studies of polymetallic sulfide industrial waste nitric acid leaching were carried out. Elemental and phase composition of investigated raw material were studied with X-ray diffraction and electron microscopy methods. Calculations of the Gibbs energy change for the likely reactions of sulfide minerals with nitric acid were performed. In order to determine the most probable conditions of the sulfide industrial waste leaching in nitric acid, as well as the mutual influence of the produced pulp components on the performance of the process, the kinetics evaluation of multicomponent sulfide industrial waste in a nitric medium was studied using mathematical methods.</p>


2020 ◽  
Vol 264 ◽  
pp. 121675
Author(s):  
Z.T. Ichlas ◽  
R.A. Rustandi ◽  
M.Z. Mubarok

JOM ◽  
2019 ◽  
Vol 71 (12) ◽  
pp. 4578-4587 ◽  
Author(s):  
Seyed Ramin Banihashemi ◽  
Bijan Taheri ◽  
Seyed Mohammad Razavian ◽  
Faraz Soltani

2020 ◽  
pp. 11-17
Author(s):  
D. A. Rogozhnikov ◽  
◽  
O. A. Dizer ◽  
K. A. Karimov ◽  
S. V. Zakharian ◽  
...  

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