scholarly journals Recovery of Lead and Zinc from Zinc Plant Leach Residues by Concurrent Dissolution-Cementation Using Zero-Valent Aluminum in Chloride Medium

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 531 ◽  
Author(s):  
Marthias Silwamba ◽  
Mayumi Ito ◽  
Naoki Hiroyoshi ◽  
Carlito Baltazar Tabelin ◽  
Ryota Hashizume ◽  
...  
Keyword(s):  
Toxic Metal ◽  
Lead Removal ◽  
Secondary Source ◽  
Metal Compounds ◽  
Low Concentration ◽  
Zinc Plant ◽  
Lead And Zinc ◽  
Hcl Concentration ◽  
Solid Liquid ◽  
Solid Liquid Separation

Zinc plant leach residues (ZPLRs) contain significant amounts of metal compounds of lead (Pb), zinc (Zn), iron (Fe), etc., hence, they are considered as a secondary source of metals. On the other hand, ZPLRs are regarded as hazardous materials because they contain heavy metals that pollute the environment. Resources and environmental concerns of ZPLRs were addressed in this study by removing/recovering Pb and Zn using a concurrent dissolution and cementation technique. To cement the dissolved Pb and Zn in leaching pulp, zero-valent aluminum (ZVAl) was added during ZPLRs leaching in the hydrochloric (HCl)–sodium chloride (NaCl) solution. The resulting cemented metals were agglomerated and separated by sieving. Lead removal increased with increasing both NaCl and HCl concentrations. However, when ZVAl was added, significant Pb removal was achieved at a low concentration. Zinc was not cemented out of the pulp using ZVAl and its recovery from ZPLRs was dependent on the HCl concentration only. By applying a concurrent dissolution and cementation technique, both Pb and Zn were removed using a low concentration of NaCl, and most importantly Pb—the most toxic metal in ZPLRs—was captured and separated before the solid-liquid separation, hence, eliminating the need for extensive washing of the generated residues to remove the inherent residual solution.

Removal of Toxic Metal Ions from Solutions Using Industrial Solid Byproducts

1993 ◽  
Vol 27 (10) ◽  
pp. 83-93 ◽  
Author(s):  
A. I. Zouboulis ◽  
K. A. Kydros ◽  
K. A. Matis
Keyword(s):  
Toxic Metals ◽  
Toxic Metal ◽  
Industrial Wastes ◽  
Mineral Particles ◽  
Solid Adsorbent ◽  
Metals Removal ◽  
Environmental Considerations ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
By Products

Nowadays the problem of industrial wastes handling and disposal is increasing continuously, as more strict environmental considerations have to be taken into account. In this paper, selected experimental results are presented from our current research in toxic metals removal (e.g. Cu, Pb, As), related to the applications of mineral particles as by-products (red mud, pyrite, dolomite, etc.) for the induced removal of toxic metals from aqueous solutions. These by-products, existing in finely divided form and considered rather as solid industrial wastes, have been used as a cheap solid adsorbent or substrate. Appropriate methods for the subsequent solid/liquid separation were examined, among them flotation. Different parameters were tested and high removals of toxic metals were achieved. In this way, a useful application may be realized for the waste mineral particles.

Toxic metals removal from dilute solutions by biosorptive flotation

1995 ◽  
Vol 32 (9-10) ◽  
pp. 211-220
Author(s):  
A. I. Zouboulis ◽  
P. Solari ◽  
K. A. Matis ◽  
G. A. Stalidis
Keyword(s):  
Toxic Metal ◽  
Separation Process ◽  
Dissolved Air Flotation ◽  
Metals Removal ◽  
Dilute Aqueous Solutions ◽  
Flotation Technique ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
Digested Sewage Sludge ◽  
Dissolved Air

Toxic metal ions (cadmium, nickel and zinc), considered as priority pollutants, were removed from dilute aqueous solutions by sorption onto non-living (sterilized) anaerobically digested sewage sludge. The desorption of cadmium from metal-laden sludge was also examined. Flotation was subsequently applied as an effective solid/liquid separation process. The dissolved-air flotation technique was applied for the generation of fine bubbles and, in parallel, electrokinetic measurements were carried out. Promising results were succeeded from the combined process of biosorption/flotation (termed biosorptive flotation).

scholarly journals Methanesulfonic acid: a sustainable acidic solvent for recovering metals from the jarosite residue of the zinc industry

2019 ◽  
Vol 21 (19) ◽  
pp. 5394-5404 ◽  
Author(s):  
Thupten Palden ◽  
Bieke Onghena ◽  
Mercedes Regadío ◽  
Koen Binnemans
Keyword(s):  
Methanesulfonic Acid ◽  
Liquid Separation ◽  
Lead And Zinc ◽  
P Leaching ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
Zinc Industry

Leaching the industrial jarosite residue with pure methanesulfonic acid resulted in a solid–liquid separation of iron from dissolved lead and zinc by precipitation.

Nitrogen Removal in a Real-Time Controlled Sequencing Batch Membrane Bioreactor

2010 ◽  
Vol 5 (3) ◽  
Author(s):  
Cheng-Nan Chang ◽  
Li-Ling Lee ◽  
Han-Hsien Huang ◽  
Ying-Chih Chiu
Keyword(s):  
Real Time ◽  
Nitrogen Removal ◽  
Membrane Bioreactor ◽  
Synthetic Wastewater ◽  
Real Time Control ◽  
Time Control ◽  
Cake Layer ◽  
On Line ◽  
Solid Liquid ◽  
Solid Liquid Separation

The performance of a real-time controlled Sequencing Batch Membrane Bioreactor (SBMBR) for removing organic matter and nitrogen from synthetic wastewater has been investigated in this study under two specific ammonia loadings of 0.0086 and 0.0045g NH4+-N gVSS−1 day−1. Laboratory results indicate that both COD and DOC removal are greater than 97.5% (w/w) but the major benefit of using membrane for solid-liquid separation is that the effluent can be decanted through the membrane while aeration is continued during the draw stage. With a continued aeration, the sludge cake layer is prevented from forming thus alleviating the membrane clogging problem in addition to significant nitrification activities observed in the draw stage. With adequate aeration in the oxic stage, the nitrogen removal efficiency exceeding 99% can be achieved with the SBMBR system. Furthermore, the SBMBR system has also been used to study the occurrence of ammonia valley and nitrate knee that can be used for real-time control of the biological process. Under appropriate ammonia loading rates, applicable ammonia valley and nitrate knee are detected. The real-time control of the SBMBR can be performed based on on-line ORP and pH measurements.

Investigations on the filtration of natural aquatic suspensions supported by dosing small amounts of Fe(III)-salts (βFe ≤ 0.1 mg.L-1): mode of action and basic design criteria

2002 ◽  
Vol 2 (2) ◽  
pp. 91-98
Author(s):  
R. Winzenbacher ◽  
R. Schick ◽  
H.-H. Stabel ◽  
M. Jekel
Keyword(s):  
Large Scale ◽  
Suspended Solids ◽  
Iron Hydroxides ◽  
Essential Step ◽  
Iron Salts ◽  
Alkaline Earths ◽  
Co Precipitation ◽  
Solid Liquid ◽  
Solid Liquid Separation

Improved removal of particles during the treatment of natural aquatic suspensions has been achieved by pre-ozonation and the addition of small quantities of iron salts (βFe ≤ 0.1 mg.L-1; “Fe(III)-assisted filtration”) followed by rapid filtration. As shown by investigations on a large-scale installation at Lake Constance Water Supply, this procedure reliably reduces suspended solids by at least 2-3 powers of ten in long-term use. However, the high efficacy of Fe(III)-assisted filtration cannot be explained on the basis of known coagulation mechanisms (like adsorption-charge neutralization, co-precipitation). Instead, the essential step was found to be the conditioning of the filter medium by coating it with colloids containing Fe(OH)3, and this “Fe coating” process occurs only in the presence of alkaline earths (especially Ca2+). According to further experiments, the enhanced solid-liquid separation was ultimately traced to chemical interactions such as the formation of calcium-organic association structures between the iron hydroxides and other solids. For design of Fe(III)-assisted filtration steps, finally, a βCa/DOC ratio above 40 mg.mg-1 and pre-oxidation with ozone dosages not exceeding 2 mg O3/mg DOC was recommended.

scholarly journals Fundamental Study of Palladium Recycling Using “Dry Aqua Regia” Considering the Recovery from Spent Auto-catalyst

2021 ◽  
Author(s):  
Akihiro Yoshimura ◽  
Shunta Tochigi ◽  
Yasunari Matsuno
Keyword(s):  
Potassium Chloride ◽  
Platinum Group Metals ◽  
Recycling Process ◽  
Fundamental Study ◽  
Aqua Regia ◽  
Sodium Chloride Solutions ◽  
Pure Compounds ◽  
The Difference ◽  
Solid Liquid ◽  
Solid Liquid Separation

AbstractIn this research, a recycling process for palladium using “dry aqua regia,” which consists of iron(III) chloride–potassium chloride, was proposed. Palladium was dissolved in “dry aqua regia,” and the dissolved palladium was recovered by leaching with potassium chloride solution with added ammonium chloride and nitric acid. Palladium was almost completely dissolved in 3 h at 600 K, and the recovery ratio of dissolved palladium was up to 80%. In addition, the dissolution of palladium in coexistence with platinum and the dissolution of platinum-palladium alloy by “dry aqua regia” were also tested. The dissolved palladium and platinum were separated and recovered by solid–liquid separation technique using the difference in solubility of their compounds in potassium chloride and sodium chloride solutions. As a result, pure compounds of each element were recovered. This result suggested the possibility of using “dry aqua regia” for the separation of platinum-group metals. Graphical Abstract

Intensification of solid–liquid separation by thermal sedimentation in pressure oxidative leaching process of chromite

2021 ◽  
Vol 164 ◽  
pp. 106825
Author(s):  
Xiaoyu Tang ◽  
Shihao He ◽  
Facheng Qiu ◽  
Xianfeng Qin ◽  
Xuejun Quan ◽  
...  
Keyword(s):  
Liquid Separation ◽  
Leaching Process ◽  
Oxidative Leaching ◽  
Solid Liquid ◽  
Solid Liquid Separation
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