An effective separation process of arsenic, lead, and zinc from high arsenic-containing copper smelting ashes by alkali leaching followed by sulfide precipitation

2020 ◽  
Vol 38 (11) ◽  
pp. 1214-1221
Author(s):  
Yuhui Zhang ◽  
Xiaoyan Feng ◽  
Bingjie Jin
Keyword(s):  
Separation Efficiency ◽  
Separation Process ◽  
Copper Smelting ◽  
Solid Ratio ◽  
Effective Separation ◽  
Lead And Zinc ◽  
Valuable Metals ◽  
Alkali Leaching ◽  
Sulfide Precipitation ◽  
High Arsenic

Separation of arsenic and valuable metals (Pb, Zn, Cu, Bi, Sn, In, Ag, Sb, etc.) is a core problem for effective utilization of high arsenic-containing copper smelting ashes (HACSA). This study developed an effective separation process of arsenic, lead, and zinc from HACSA via alkali leaching followed by sulfide precipitation. The separation behaviors and optimum conditions for alkali leaching of arsenic and sulfide precipitation of lead and zinc were established respectively as follows: NaOH concentration 3.81 M; temperature 80°C; time 90 minutes; liquid-to-solid ratio 4:1; agitation speed 450 revolutions/minute (r/min) and 2.0 times of theoretical quantity of sodium sulfide (Na2S); temperature 70°C; and time 60 minutes. The results indicated that the leaching rates of As, Pb, and Zn were 92.4%, 36.9% and 13.4%, respectively. More than 99% of lead and zinc were precipitated from the alkali leachate. The scanning electron microscopy/energy dispersive X-ray spectroscopy study confirmed that arsenic was dissolved from HACSA into the alkali leachate. Furthermore, lead and zinc were precipitated as sulfides from the alkali leachate. The proposed process was a good technique for separation of arsenic and enrichment of valuable metals for further centralized treatment separately. It provided high separation efficiency of arsenic and valuable metals, as well as low environmental pollution.

Performance of a Novel Rotating Gas-Liquid Separator

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
G. P. Willems ◽  
J. P. Kroes ◽  
M. Golombok ◽  
B. P. M. van Esch ◽  
H. P. van Kemenade ◽  
...  
Keyword(s):  
Separation Efficiency ◽  
Collection Efficiency ◽  
Separation Process ◽  
Major Influence ◽  
Descriptive Model ◽  
Capital Costs ◽  
Fine Droplet ◽  
Phase Separator ◽  
Scale Design ◽  
Liquid Separator

A novel gas separation process makes use of a rotating phase separator to separate micron-sized droplets from a gas stream. Based on an industrial scale design, a water/air separator is constructed and tested. The first experiment concerns the drainage of large fractions of separated liquid. During operation, drainage is observed via windows and a descriptive model is formulated. Because of the major influence on overall separation efficiency, liquid drainage is a key issue in the separator design. The second experiment comprises a droplet collection efficiency measurement using micron-sized droplets dispersed within the airstream. The separation efficiency of fine droplet removal is measured. This is an important factor in reducing capital costs.

scholarly journals Detoxification of Arsenic-Containing Copper Smelting Dust by Electrochemical Advanced Oxidation Technology

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1311
Author(s):  
Meng Li ◽  
Junfan Yuan ◽  
Bingbing Liu ◽  
Hao Du ◽  
David Dreisinger ◽  
...  
Keyword(s):  
Solid Waste ◽  
Arsenic Removal ◽  
Removal Rate ◽  
Advanced Oxidation ◽  
Copper Smelting ◽  
Lead And Zinc ◽  
Heavy Nonferrous Metals ◽  
Advanced Oxidation Technology ◽  
Oxidation Technology ◽  
Smelting Dust

A large amount of arsenic-containing solid waste is produced in the metallurgical process of heavy nonferrous metals (copper, lead, and zinc). The landfill disposal of these arsenic-containing solid waste will cause serious environmental problems and endanger people’s health. An electrochemical advanced oxidation experiment was carried out with the cathode modified by adding carbon black and polytetrafluoroethylene (PTFE) emulsion. The removal rate of arsenic using advanced electrochemical oxidation with the modified cathode in 75 g/L NaOH at 25 °C for 90 min reached 98.4%, which was significantly higher than 80.69% of the alkaline leaching arsenic removal process. The use of electrochemical advanced oxidation technology can efficiently deal with the problem of arsenic-containing toxic solid waste, considered as a cleaner and efficient method.

scholarly journals Investigation of the effect of several parameters on the applicability of magnetic separation method

2021 ◽  
pp. 69-73
Author(s):  
Tariq Al-Azab ◽  
Jamil Haddad ◽  
Fadi Alfaqs
Keyword(s):  
Magnetic Separation ◽  
Centrifugal Force ◽  
Magnetic Force ◽  
Separation Efficiency ◽  
Industrial Applications ◽  
Separation Process ◽  
Silica Sand ◽  
Sand Particle ◽  
Roll Speed ◽  
Magnetic Separator

Purpose. This research investigates the separation process performed by a magnetic separator. The magnetic separation process is used to isolate ferrous materials from those which are not. Hence, a prototype of a dry magnetic separator is designed. It should be said that this study defines the effect of different parameters (roll speed, magnetic force, and mass of silica sand particle) on separation efficiency. Methodology. The influence of several parameters of the magnetic separator such as magnetic force, centrifugal force, and properties of particle (mass, shape, etc.) were studied theoretically and simulated by SolidWorks software. The optimum conditions of the magnetic separator were obtained, and several trials were performed to find the point that results in a lower effect of roller speed and a higher effect of the magnetic force on the particle in order to achieve higher separating efficiency. Findings. The results show that the centrifugal force are the most important variable influencing separating efficiency. Moreover, it was found that blade angle magnitude of (174) degree with magnetic force between (1.71E-05 to 6.3E-05 N) and roll speed from (84 to 105 rpm) are the optimum separating conditions to reach higher rate of the separating process. Originality. This is the first time that the effect of the gap distance between the magnet and the feeding particles on the magnetic force has been studied. Furthermore, the effect of centrifugal force on magnetic separator force is investigated theoretically and numerically in order to be compared for different parameters. Practical value. The new prototype design of the magnetic separating unit is promising and efficient since the parameters can be varied based on the type and characteristics of materials. It is also revealed that separating time of the materials is reduced. Hence, this type of construction of a magnetic separator is recommended for industrial applications.

scholarly journals SLAGS OF THE METALLURGICAL PLANTS OF ARMENIA AT FINE GRINDING

2019 ◽  
Vol 62 (1) ◽  
pp. 8-14 ◽  
Author(s):  
V. A. Martirosyan ◽  
M. E. Sasuntsyan
Keyword(s):  
Chemical Properties ◽  
Complex Compounds ◽  
Raw Material ◽  
Copper Smelting ◽  
Iron Silicides ◽  
Fine Grinding ◽  
High Temperature Synthesis ◽  
Valuable Metals ◽  
Physical And Chemical ◽  
The Impact

In connection with the development of copper and molybdenum production in Armenia, it becomes necessary to develop a technology for processing the slags of the functioning metallurgical plants to extract valuable metals from these slags. It concerns the copper slags of Alaverdi Copper-Smelting Plant with a content of FeO ~50  % and the molybdenum slags of Yerevan “Pure Iron” Plant with a content of SiO2 ~80  %. These slags are obtained at high temperatures (with FeO·SiO2 , CaO·SiO2 , Fe3 O4 ) and, therefore, they are less active to be used later. Meanwhile, the mentioned slags are rich in iron and silicon oxides and can serve as a cheap raw material for producing iron silicides. The iron silicides can be used in micro- and nanoelectronics, as well as in metallurgy as an alloying additive in the production of steels of special physical and chemical properties. The production of such valuable silicides from an inexpensive raw material is important for Republic of Armenia and is of not only economic, but also ecological significance. To obtain iron silicides, a method of combined aluminothermal reduction of primarily mechanoactivated copper and molybdenum slags is proposed. The preliminary mechanoactivation allows to purposefully affect the structure of the reaction mixture and parameters of the self-propagating high-temperature synthesis (SHS), thus ensuring the possibility of regulating the structure and phase composition of the synthesized silicides. This work considers issues on the impact of transformation and phase formation on the morphology of slags of copper and molybdenum production in the functioning Armenian metallurgical plants at mechanochemical activation by the method of fine grinding in a vibromill. It is shown that at fine grinding (up to 10  mcm), the slags, containing small-reactivity complex compounds of iron and silicon (fayalite, magnetite, quarzite) undergo profound chemical changes, transforming into amorphous oxides. The obtained activated oxides can serve as a raw material for producing iron- and silicon-containing alloys – iron silicides.

scholarly journals Treating Wet Oil in Amara Oil Field Using Nanomaterial (SiO2) With Different Types of De emulsifiers

2021 ◽  
Vol 22 (1) ◽  
pp. 29-38
Author(s):  
Ayat Ragheb Alkarbalaee ◽  
Adel Sharif Hammadi ◽  
Ghassan Hamid Abdul Majeed
Keyword(s):  
Acidic Medium ◽  
Separation Efficiency ◽  
Sodium Dodecyl ◽  
Separation Process ◽  
Oil Field ◽  
Oil Refining ◽  
Ph Values ◽  
Different Types ◽  
Separation Results ◽  
High Separation

One of the most important problems in the oil production process and when its continuous flow, is emulsified oil (w/o emulsion), which in turn causes many problems, from the production line to the extended pipelines that are then transported to the oil refining process. It was observed that the nanomaterial (SiO2) supported the separation process by adding it to the emulsion sample and showed a high separation rate with the demulsifiers (RB6000) and (sebamax) where the percentage of separation was greater than (90 and 80 )%  respectively, and less than that when dealing with (Sodium dodecyl sulfate and Diethylene glycol), the percentage of separation was (60% and 50%) respectively.    The high proportion of (NaCl + distilled water) raises the probability of the separation efficiency as the separation was (88.5,79)% and (65.5, 55) %  for (RB6000, SebaMax)respectively with (SiO2) at 70 °C, while the results of separation were (77,85)% and (65,40)  for (RB6000, Seba Max) respectively with (SiO2) at 50 °C after 120 minutes, where the (w/o ratio) was (9:1) for the high separation results and (7:3) for the lower separation results, at a speed of (12000rpm), and with a salt concentration of (1500) ppm, and less of these results at lower volumetric and temporal conditions. The (NaCl) salt deals with the wall films separating the droplets and reduces their viscosity [1].    As for the pH factor, it is at the value (2 and 3) represent a stable emulsion that is difficult to separate easily, but with the passage of raising the pH away from the acidic medium and near to the basic direction, a significant increase in the separation process was observed compared with the acidic medium at lower values, after 120 minutes the separation seemed to be good efficient, reaching (60 and 70) % respectively, while at the same time the emulsion reached a more efficient separation level with a pH of (  8 and 7) equal to (80 and 87.3)  %, at 50 °C with SebaMax demulsifier in presence of (SiO2), and with the same pH values, an increase was observed in the separation with the increase in temperature to (70 °C), then it returns to be a reverse emulsifier when the value exceeds (10) to (11, 12, 13).

scholarly journals Electrostatic Separation of Copper and Glass Particles in Pretreated Automobile Shredder Residue

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 879
Author(s):  
Beom-Uk Kim ◽  
Chul-Hyun Park
Keyword(s):  
Separation Efficiency ◽  
Separation Process ◽  
Electrostatic Separation ◽  
Physical Separation ◽  
Shredder Residue ◽  
Conductive Materials ◽  
Automobile Shredder Residue ◽  
Small Glass ◽  
Increasing Demand ◽  
Optimum Separation

There is increasing demand for an efficient technique for separating automobile shredder residue (ASR) obtained from end-of-life vehicles (ELVs). A particular challenge is the physical separation of conductive materials from glass. In this study, the performance of pretreatment and induction electrostatic separation process was evaluated. The results show that a sieving/washing (combination of sieving and washing) pretreatment was the most effective for removing conductive material compared to electrostatic separation alone. The optimum separation efficiency of copper products was achieved with an applied voltage of 20 kV, a relative humidity of less than 35%, and a splitter position of 8 cm. Although the separation efficiency was slightly reduced when some small glass particles remained attached to the conductive materials, the separation efficiency of copper from the pretreated ASR dramatically increased to 83.1% grade and 90.4% recovery, compared to that of raw ASR (34.3% grade and 58.6% recovery). Based on these results, it was demonstrated that the proposed sieving/washing pretreatment was proficient at removing conductive materials from glass; thus, it has the potential to significantly improve the efficiency of electrostatic separation for ASR.

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