Fe(II)-induced transformation of Jarosite residues generated from zinc hydrometallurgy: Influence on metals behaviors during acid washing

Over time, performance of tubular backpulse pressure filters in kraft mills deteriorates, even with regular acid washing. Unscheduled filter replacement due to filter plugging results in significant costs and may result in mill downtime. We identified acid-insoluble filter-plugging materials by scanning electron microscope/energy-dispersion X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis in both polypropylene and Gore-Tex™ membrane filter socks. The major filter-plugging components were calcium sulfate (gypsum), calcium phosphate (hydroxylapatite), aluminosilicate clays, metal sulfides, and carbon. We carried out detailed sample analysis of both the standard acid-washing procedure and a modified procedure. Filter plugging by gypsum and metal sulfides appeared to occur because of the acid-washing procedure. Gypsum formation on the filter resulted from significant hydrolysis of sulfamic acid solution at temperatures greater than 130°F. Modification of the acid-washing procedure greatly reduced the amount of gypsum and addition of a surfactant to the acid reduced wash time and mobilized some of the carbon from the filter. With surfactant, acid washing was 95% complete after 40 min.

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New surface treatment techniques to minimize copper alloy leaching in drinking water

Water Practice & Technology ◽

10.2166/wpt.2012.082 ◽

2012 ◽

Vol 7 (4) ◽

Author(s):

Norikazu Sugaya

Keyword(s):

Surface Treatment ◽

Raw Materials ◽

Organic Film ◽

Forming Process ◽

Mixed Acid ◽

Treatment Techniques ◽

Acid Washing ◽

Washing Process ◽

Film Forming ◽

Materials Used

This new surface treatment is simple and easy as well as low in cost. The processes can even be performed by hand. Pharmaceutical raw materials used for the surface treatment, such as hydrochloric acid and nitric acid used in a mixed acid washing process and vegetable oil used in an organic film forming process, are easily obtained in many countries.

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Inactivation kinetics of beer spoilage bacteria (Lactobacillus brevis, Lactobacillus casei, and Pediococcus damnosus) during acid washing of brewing yeast

Food Microbiology ◽

10.1016/j.fm.2020.103513 ◽

2020 ◽

Vol 91 ◽

pp. 103513

Author(s):

Allan R.G. Munford ◽

Rafael D. Chaves ◽

Anderson S. Sant’Ana

Keyword(s):

Lactobacillus Casei ◽

Lactobacillus Brevis ◽

Inactivation Kinetics ◽

Brewing Yeast ◽

Acid Washing ◽

Spoilage Bacteria ◽

Beer Spoilage ◽

Kinetics Of

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A comprehensive review of processing strategies for iron precipitation residues from zinc hydrometallurgy

Cleaner Engineering and Technology ◽

10.1016/j.clet.2021.100214 ◽

2021 ◽

pp. 100214

Author(s):

Lukas Hoeber ◽

Stefan Steinlechner

Keyword(s):

Comprehensive Review ◽

Iron Precipitation ◽

Processing Strategies ◽

Zinc Hydrometallurgy

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Constrained Parameter Estimation for a Mechanistic Kinetic Model of Cobalt–Hydrogen Electrochemical Competition during a Cobalt Removal Process

Entropy ◽

10.3390/e23040387 ◽

2021 ◽

Vol 23 (4) ◽

pp. 387

Author(s):

Yiting Liang ◽

Yuanhua Zhang ◽

Yonggang Li

Keyword(s):

Parameter Estimation ◽

Kinetic Model ◽

Model Parameters ◽

Hydrogen Ions ◽

Removal Process ◽

Cobalt Removal ◽

Estimation Scheme ◽

Zinc Hydrometallurgy ◽

The Impact ◽

Parameter Estimation Scheme

A mechanistic kinetic model of cobalt–hydrogen electrochemical competition for the cobalt removal process in zinc hydrometallurgical was proposed. In addition, to overcome the parameter estimation difficulties arising from the model nonlinearities and the lack of information on the possible value ranges of parameters to be estimated, a constrained guided parameter estimation scheme was derived based on model equations and experimental data. The proposed model and the parameter estimation scheme have two advantages: (i) The model reflected for the first time the mechanism of the electrochemical competition between cobalt and hydrogen ions in the process of cobalt removal in zinc hydrometallurgy; (ii) The proposed constrained parameter estimation scheme did not depend on the information of the possible value ranges of parameters to be estimated; (iii) the constraint conditions provided in that scheme directly linked the experimental phenomenon metrics to the model parameters thereby providing deeper insights into the model parameters for model users. Numerical experiments showed that the proposed constrained parameter estimation algorithm significantly improved the estimation efficiency. Meanwhile, the proposed cobalt–hydrogen electrochemical competition model allowed for accurate simulation of the impact of hydrogen ions on cobalt removal rate as well as simulation of the trend of hydrogen ion concentration, which would be helpful for the actual cobalt removal process in zinc hydrometallurgy.

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Remediation of iron oxide bound Pb and Pb-contaminated soils using a combination of acid washing agents and l-ascorbic acid

RSC Advances ◽

10.1039/d0ra05327a ◽

2020 ◽

Vol 10 (62) ◽

pp. 37808-37817

Author(s):

Quan Li ◽

Yilian Li ◽

Zhe Yang ◽

Xiang Li ◽

Zhi Tang ◽

...

Keyword(s):

Ascorbic Acid ◽

Iron Oxide ◽

Contaminated Soils ◽

Temperature Dependency ◽

Acid Washing

In this study, the reductants and time–temperature dependency of dissolved FeOx–Pb were studied experimentally.

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Recovery of Zinc and Silver from Zinc Acid-Leaching Residues with Reduction of Their Environmental Impact Using a Novel Water Leaching-Flotation Process

Minerals ◽

10.3390/min11060586 ◽

2021 ◽

Vol 11 (6) ◽

pp. 586

Author(s):

Yunpeng Du ◽

Xiong Tong ◽

Xian Xie ◽

Wenjie Zhang ◽

Hanxu Yang ◽

...

Keyword(s):

Hazardous Waste ◽

Acid Leaching ◽

Copper Recovery ◽

Water Leaching ◽

Flotation Process ◽

Metal Levels ◽

Valuable Metals ◽

Leaching Experiments ◽

Zinc Hydrometallurgy ◽

Poor Stability

Zinc-leaching residue (ZLR) is a strongly acidic hazardous waste; it has poor stability, high heavy metal levels, and releases toxic elements into the environment. ZLR has potential as a valuable resource, because it contains elevated levels of zinc and silver. In this paper, the recovery of zinc (Zn) and silver (Ag) from ZLR wastes from zinc hydrometallurgy workshops using water leaching followed by flotation was studied. During water leaching experiments, the zinc and copper recovery rates were 38% and 61%, respectively. Thereafter, various flotation testing parameters were optimized and included grinding time, reagent dosages, pulp density, flotation time, and type of adjuster. Experimental results demonstrated this flotation method successfully recycled Ag and Zn. A froth product containing more than 9256.41 g/t Ag and 12.26% Zn was produced from the ZLR with approximately 80.32% Ag and 42.88% Zn recoveries. The toxicity characteristic leaching procedure (TCLP) results indicated the water-leaching flotation process not only recycled valuable metals such as zinc and silver in zinc-containing hazardous wastes but lowered the hazardous waste levels to those of general wastes and recycled wastes in an efficient, economical, and environmentally friendly way.

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