scholarly journals Effect of Pre-Treatment with Sodium Chloride/Sulfuric Acid on the Bornite Concentrate Leaching in Chloride Medium

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1674
Author(s):  
Patricio Navarro ◽  
Cristian Vargas ◽  
Fabiana Bahamonde ◽  
Matías Gómez ◽  
Daniel Espinoza ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Sodium Chloride ◽  
Sitting Time ◽  
Acid Mixture ◽  
Chloride Medium ◽  
Copper Solution ◽  
Particle Level ◽  
Mixture Prior ◽  
Pre Treatment ◽  
Sulfide Species

In this work, the effect of the pre-treatment of bornite concentrate with a sodium chloride–sulfuric acid mixture prior to leaching with chloride solutions was evaluated. The influence of the dosage of NaCl and the resting time in the copper solution was evaluated. The solid residues of the pre-treatment were characterized by XRD to evaluate the changes that took place in the bornite. The experimental results show that as the sitting time and the amount of sodium chloride added are increased, the dissolution of the sulfide species also increased. The pre-treatment affects Cu preferentially because it has greater mobility than iron in the bornite crystal lattice. The pre-treatment promotes the formation of soluble Cu and Fe species. The efficiency of the pre-treatment depends largely on the formation of hydrochloric acid in the mixture at the particle level, due to the ease with which it diffuses through the bornite particles, achieving greater penetration of the pre-treatment.

Corrosion Behavior of the Passivation 15-5PH Stainless Steel in a Sodium Chloride Medium and Sulfuric Acid

2017 ◽  
Vol 76 (1) ◽  
pp. 205-210
Author(s):  
María Lara ◽  
Octavio Covarrubias ◽  
Citlalli Gaona Tiburcio ◽  
Patricia Zambrano Robledo ◽  
José Angel Cabral ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Sulfuric Acid ◽  
Sodium Chloride ◽  
Corrosion Behavior ◽  
Chloride Medium

Corrosion, Wear, and Galling Tests of IC218, a Chromium-Bearing Alloy of Ni3Al

1988 ◽  
Vol 133 ◽  
Author(s):  
Bradford A. Dulmaine
Keyword(s):  
Sulfuric Acid ◽  
Sodium Chloride ◽  
Hydrochloric Acid ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Alumina Scale ◽  
Acid Mixture ◽  
Oil Well ◽  
Aqueous Corrosion ◽  
Bearing Alloy

ABSTRACTIC218 contains about 8.4% aluminum and about 7.8% chromium by weight and forms a tenacious alumina scale. In this work the ability of the scale to protect against aqueous corrosion and abrasive and adhesive wear was evaluated. Wrought IC218 was heat treated at 1150°C, yielding a microstructure of ordered FCC islands in a disordered FCC matrix. This material was more resistant to corrosion than common stainless steels in 96% or 98% sulfuric acid and in 5% hydrochloric acid. It was approximately equivalent to stainless steels in 10% sulfuric acid, 50% acetic acid, 50% sodium hydroxide, 5% sodium chloride, and in a sodium chloride + ferric sulfate + hydrochloric acid mixture used to test for pitting resistance. The IC218 performed poorly in 45% sulfuric acid, 20% or 65% nitric acid, 20% phosphoric acid, and in electrolytic 10% oxalic acid. It did not exhibit sensitivity to intergranular corrosion. It resisted stress corrosion cracking at a stress level equal to its yield strength, 645 MPa, in 45% magnesium chloride and in NACE TM0177, a test that simulates an oil well environment. IC218 wore more quickly than austenitic stainless steels do in a dry-sand-rubber-wheel test, but resisted galling as well as or better than most of them do.

Characteristics of Leaching of Nickel from a Mafic Overburden in Sulfuric Acid and Sodium Chloride Medium at Atmospheric Pressure

JOM ◽  
2019 ◽  
Vol 71 (12) ◽  
pp. 4616-4623
Author(s):  
Catherine K. Thubakgale ◽  
Richard K. K. Mbaya ◽  
Mxolisi B. Shongwe
Keyword(s):  
Sulfuric Acid ◽  
Sodium Chloride ◽  
Atmospheric Pressure ◽  
Chloride Medium

scholarly journals Extraction of Ta and Nb from a Coltan Bearing Ore by Means of Ammonium Bifluoride Fluorination and Sulfuric Acid Leaching

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1392
Author(s):  
Alidor Shikika ◽  
Francois Zabene ◽  
Fabrice Muvundja ◽  
Mac C. Mugumaoderha ◽  
Julien L. Colaux ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Acid Leaching ◽  
Environmental Benefits ◽  
Process Conditions ◽  
Sulfuric Acid Leaching ◽  
Mechanical Agitation ◽  
Ammonium Bifluoride ◽  
Novel Approach ◽  
Pre Treatment ◽  
Subsequent Acid

A novel approach for Ta and Nb extraction consisting of the pre-treatment of a coltan-bearing ore with an ammonium bifluoride sub-molten salt and subsequent acid leaching has been studied. The effects from ore granulometry, ammonium bifluoride (ABF) to ore mass ratio, temperature and duration of fluorination on the degree of Ta and Nb extraction were examined. The ABF to ore ratio and process temperature were found to have the most pronounced impact on extraction efficiency. The following optimal process conditions were determined: ore granulometric fraction (−75 + 45 µm), ABF-ore (5/1), fluorination temperature (200 °C) and fluorination time (2.5 h). Maintaining these parameters enabled about 94% of Ta and 95% of Nb to be brought into solution during the sulfuric-acid-leaching stage. A comparison of the proposed method with previously reported studies suggests that due to the effects of mechanical agitation and the recirculation of the HF-containing gaseous phase back into the process, the dosage rate of ABF at the fluorination stage could be reduced significantly without sacrificing the overall recovery of Ta and Nb. In such a way, the approach could offer added environmental benefits since release of fluoride-containing effluents into the environment could be limited.

scholarly journals Effect of Surface Modification with Different Acids on the Functional Groups of AF 5 Catalyst and Its Catalytic Effect on the Atmospheric Leaching of Enargite

2019 ◽  
Vol 3 (2) ◽  
pp. 45 ◽  
Author(s):  
Jahromi ◽  
Ghahreman
Keyword(s):  
Sulfuric Acid ◽  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Functional Groups ◽  
Photoelectron Spectroscopy ◽  
Elemental Sulfur ◽  
Catalytic Properties ◽  
Copper Recovery ◽  
Pre Treatment ◽  
Sulfur Adsorption

Carbon-based catalysts can assist the oxidative leaching of sulfide minerals. Recently, we presented that AF 5 Lewatit® is among the catalysts with superior enargite oxidation capacity and capability to collect elemental sulfur on its surface. Herein, the effect of acid pre-treatment of the AF 5 catalyst was studied on the AF 5 surface, to further enhance the catalytic properties of AF 5. The AF 5 catalyst was pretreated by hydrochloric acid, nitric acid and sulfuric acid. The results showed that the acid treatment drastically changes the surface properties of AF 5. For instance, the concentration of quinone-like functional groups, which are ascribed to the catalytic properties of AF 5, is 45.4% in the sulfuric acid pre-treatment AF 5 and only 29.8% in the hydrochloric acid-treated AF 5. Based on the C 1s X-ray photoelectron spectroscopy (XPS) results the oxygenated carbon is 30.6% in the sulfuric acid-treated AF 5, 29.2% in the nitric acid-treated AF 5 and 28.3% in the hydrochloric acid-treated AF 5. The nitric acid pre-treated AF 5 resulted in the highest copper recovery during the oxidative enargite leaching process, recovering 98.8% of the copper. The sulfuric acid-treated AF 5 recovered 97.1% of the enargite copper into the leach solution. Among different leaching media and pre-treatment the lowest copper recovery was achieved with the HCl pre-treated AF 5 which was 88.6%. The pre-treatment of AF 5 with acids also had modified its elemental sulfur adsorption capacity, where the sulfur adsorption on AF 5 was increased from 30.9% for the HCl treated AF 5 to 51.1% for the sulfuric acid-treated AF 5.

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