scholarly journals Study of Nickel Leaching Using Sulfuric Acid and Phosphoric Acid on The Selectivity Nickel Ore

2021 ◽  
Vol 16 (3) ◽  
pp. 393
Author(s):  
Syamsul Hidayat ◽  
Sri Yulianti ◽  
Dian Anggreini ◽  
Syamsul Bahtiar
Keyword(s):  
Sulfuric Acid ◽  
Phosphoric Acid ◽  
Nickel Content ◽  
Operating Time ◽  
Solution Concentration ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Low Grade ◽  
Atmospheric Conditions ◽  
Nickel Leaching

Study of nickel leaching using sulfuric acid and phosphoric acid on the selectivity of low-grade laterite nickel ore under atmospheric conditions has been successfully carried out. In this study, the laterite nickel leaching process was carried out by varying the solution concentration and operating time. The concentrations of sulfuric acid and phosphoric acid solutions were varied at 5 M and 6 M concentrations, while the operating time was varied at 4 hours and 6 hours. For other operating conditions, it is kept constant with an operating temperature of 90 ℃, pulp density 15% w / v, particle size ≤ 200 mesh. After that, the analysis stage was carried out using an atomic absorption spectroscopy (AAS) tool to determine the nickel content in the sample. The results showed that the highest nickel recovery was obtained at the concentration of 5 M sulfuric acid solution of 2.60% and 5 M phosphoric acid of 2.59% with the optimum operating time at 4 hours of operating time.

The treatment of zinc-cyanide electroplating rinse water using an electrocoagulation process

2013 ◽  
Vol 68 (10) ◽  
pp. 2220-2227 ◽  
Author(s):  
Elif Senturk
Keyword(s):  
Electrode Material ◽  
Operating Time ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Operating Parameters ◽  
Initial Ph ◽  
Electrocoagulation Process ◽  
Removal Efficiencies ◽  
Rinse Water ◽  
Electrode Connection

This paper investigates the treatment of zinc-cyanide electroplating rinse water using an electrocoagulation process (ECP). The effects of operating parameters such as electrode material, current density (2.5–40 A/m2), operating time (0–60 min), initial pH (5–12) and electrode connection mode (monopolar parallel (MP-P), monopolar series and bipolar series) on the ECP were evaluated to find the optimum operating conditions. At 20 A/m2, 60 min, the highest removal efficiencies were obtained with 85 and 99% for Fe and 64 and 33% for Al electrodes, for cyanide and zinc, respectively. The optimum operating conditions were found to be 30 A/m2 and 40 min, for the Fe electrode at the original pH (9.5) of the rinse water. Considering efficiency and economy, the MP-P connection mode was determined as the optimum connection mode.

OPTIMIZATION OF ELECROSPINNING OF PVDF SCAFFOLDS FABRICATION USING RESPONSE SURFACE METHOD

2015 ◽  
Vol 75 (6) ◽  
Author(s):  
Madana Leela Nallappan ◽  
Mohamad Mahmoud Nasef
Keyword(s):  
Experimental Design ◽  
Response Surface ◽  
Vinylidene Fluoride ◽  
Fibre Diameter ◽  
Solution Concentration ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Statistical Validation ◽  
Electric Voltage ◽  
Average Fibre Diameter

Poly(vinylidene fluoride) (PVDF) scaffolds were prepared via electrospinning. The response surface methodology (RSM) was used to optimize the parameters that influence the average fibre diameter. The objective is to produce fibres with small diameters. The factors considered for experimental design were the applied electric voltage, the PVDF solution concentration, and the distance between the needle tip and the collecting drum. The Central Composite Design (CCD) was used to generate the experimental design whilst the analysis of variance (ANOVA) was performed to obtain statistical validation of regression models and to study the interaction between input parameters. The optimum operating conditions that guaranteed PVDF scaffolds with small nanofibre diameter were in the voltage and concentration range of 16-20 kV and 10-14wt%.

scholarly journals Electrocoagulation for ammonium removal in Nam Son landfill leachate

2017 ◽  
Vol 33 (2) ◽  
Author(s):  
Thanh Son Le ◽  
Khải Cao Lê ◽  
Hà Thị Nguyễn ◽  
Linh Tuấn Đoàn ◽  
Anh Thị Đoàn
Keyword(s):  
Landfill Leachate ◽  
Operating Time ◽  
Operating Conditions ◽  
Current Intensity ◽  
Optimum Operating ◽  
Applied Current ◽  
Ammonium Removal ◽  
Treatment Performance ◽  
Iron Electrodes ◽  
Initial Ph

In this paper, an electrocoagulation reactor was set up to investigate the ammonium removal in Nam Son landfill leachate. The research focused on studying several factors that affect to the ammonium removal namely current intensity, operating time, initial pH and electrode materials. Mono-polar electrocoagulation reactor was conducted in a batch system with iron electrodes and 1.8 L leachate. The research indicated that current intensity and operating time are directly proportional with NH4+ treatment performance. When applied current increased from 1 to 4A, the NH4+ removal percentage went up from 14.03 to 24.99% after a 1 hour treatment. The effect of initial pH in range of 5 to 10 has showed that the best NH4+ treatment efficiency in neutral and mild alkaline conditions. It is noticeable that iron electrodes had higher NH4+ removal than aluminum one during nearly the first 40 min, however this trend has been reversed later with the advantage belonging to aluminum anode. The optimum operating conditions found are aluminum electrodes, applied current of 3A, electrolysis time of 60 min, raw pH of 8, resulting in NH4+ treatment performance of approximately 24%. As a result, the electrocoagulation method is not really effective in NH4+ removal and might be applied as a pre-treatment.

scholarly journals Electrocoagulation coupled with adsorption for effective removal of eosin yellow and nigrosin dyes in aqueous solution

2019 ◽  
Vol 11 (1) ◽  
pp. 97-106
Author(s):  
Vinothkumar K ◽  
Sugumaran T. ◽  
Venkateshwari S
Keyword(s):  
Electrical Conductivity ◽  
Current Density ◽  
Dye Removal ◽  
Adsorption Process ◽  
Supporting Electrolyte ◽  
Operating Time ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Effective Removal ◽  
Eosin Yellow

This paper deals with the study of suitability and efficiency of electrocoagulation (EC) coupled with adsorption to remove dye from synthetic dye solution. The EC cell consisted of mild steel (MS)/copper plates as electrodes and dye solution as electrolyte. The effects of operating time, concentration, supporting electrolyte, current density and pH have been investigated to find out the optimum operating conditions for EC. The concentration of dye was successfully reduced (EY) ?50% and Nigrosin dye ?99% during EC under the optimum operating conditions of initial concentration 0.5ppm, 20ppm, current density 0.04 A/cm2, 0.015 A/cm2, supporting electrolyte 4g, 4g, electrolysis time 20min, 10min, Eosin Yellow and Nigrosin dye respectively, the removal efficiency of the dyes were found 46.69% and 99%, electrical conductivity were 125.0 S/m and 105.7 S/m and TDS left in the EC treated solution were 82.0 and 69.3 ppt. Further proceedings with solution for adsorption process help to improve the dye removal. Results of the studies are electrical conductivity 20 S/m and TDS 30 ppt for EY, for Nigrosin 64.2 S/m and 42.1 ppt.

scholarly journals Removal of COD and BOD from biologically treated municipal wastewater by electrochemical treatment

2013 ◽  
Vol 5 (2) ◽  
pp. 475-481 ◽  
Author(s):  
Arun Kumar Sharma ◽  
A. K. Chopra
Keyword(s):  
Municipal Wastewater ◽  
Operating Cost ◽  
Operating Time ◽  
Sewage Treatment Plant ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Initial Ph ◽  
Treated Municipal Wastewater ◽  
Maximum Removal

The present investigation observed the effect of current density (CD), operating time (OT), inter electrode distance (IED), electrode area (EA), initial pH and settling time (ST) using Fe-Fe electrode combination on the removal of chemical oxygen demand (COD) and biochemical oxygen demand (BOD) from biologically treated municipal wastewater (BTMW) of Sewage Treatment Plant (STP). The maximum removal of COD (92.35%) from BTMW was found with the optimum operating conditions of CD (2.82 A/m2), OT (40 mins.), IED (0.5 cm), EA (160 cm2), initial pH (7.5) and ST (60 min.), while the maximum removal of BOD (84.88%) was found with the ST (30 min.) at the same operating conditions. There was no need of pH adjustment of the BTMW during ET as the optimal removal efficiency was close to the pH of 7.5. Under optimal operating conditions, the operating cost was found to be 54.29 Rs./m3 / 1.08 US$/m3 in terms of the electrode consumption (78.48 x 10-5 kg Al/m3 ) and energy consumption (108.48 Kwh/m3).

scholarly journals Membrane Distillation Crystallization Hybrid Process for Zero Liquid Discharge in QAFCO Plant

2021 ◽  
Author(s):  
Mona Gulied ◽  
Sifani Zavahir ◽  
Tasneem Elmakki ◽  
Hazim Qiblawey ◽  
Bassim Hameed ◽  
...  
Keyword(s):  
Research Work ◽  
Membrane Distillation ◽  
Economic Feasibility ◽  
Operating Conditions ◽  
Hybrid Process ◽  
Optimum Operating ◽  
Low Grade ◽  
Water Recovery ◽  
Ongoing Research ◽  
Liquid Discharge

Qatar fertilizer company (QAFCO) is one of the world’s largest single site producer of ammonia and urea with production capacity of 12,900 metric tons per day. Currently, QAFCO faces major challenges in terms of water streams management that is generated from many processes such as wastewater from Harbor-Bosch process and brine solution from multi-stage flash (MSF) desalination process. To protect the environment; QAFCO has been making an effort to minimize the disposal of all types of water disposed into the sea. Here, this project proposes to develop a viable and economically effective process that can reach zero-liquid discharge (ZLD) of all processed water or wastewater from QAFCO facilities. The best method for ZLD is membrane distillation crystallization (MDC) hybrid process that concentrates and minimizes the volume of wastewater/brine streams to form solid through crystallizer. Membrane distillation (MD) is a thermally driven membrane process. It applies low-grade energy to create a thermal gradient across a microporous hydrophobic to vaporize water in the feed stream and condense the permeated vapor in the cold side. This research work aims to evaluate the performance of MDC for ZLD using commercial/fabricated electrospun nanofiber membrane (ENM) PVDF –base membranes at different type water streams. A general observation, higher water vapor flux and water recovery were exhibited at higher feed conductivity at 70°C. Moreover, the fabricated hydrophobic PVDF ENMs results confirmed the formation of nanofiber at the membrane surface using scanning electron microscopy (SEM). In addition, the water contact angle values of PVDF ENMs were greater than 100° and have stable mechanical and chemical properties. The ongoing research work will conduct a comparison between the optimum PVDF ENMs and the commercial MD membranes in terms of water recovery, salt rejection%, fouling/scaling, amount of collected solid and energy consumption at optimum operating conditions in MDC. In addition, it will perform a techno- economic feasibility assessment of the MDC hybrid process.

Steady-State Simulation of Hybrid Nickel Leaching Circuit Using Syscad

2006 ◽  
Vol 1 (1) ◽  
Author(s):  
Abbas Razavimanesh ◽  
Moses Tade ◽  
John Rumball ◽  
Vishnu Pareek
Keyword(s):  
New Technology ◽  
Nickel Content ◽  
Acid Leaching ◽  
Process Variable ◽  
Low Grade ◽  
Business Decisions ◽  
Hydrometallurgical Processing ◽  
Process Chemistry ◽  
Steady State Simulation ◽  
Nickel Leaching

There is an increasing focus on the hydrometallurgical processing of nickel-rich laterite ore due to declining global reserves of nickel sulphides. The development of new technology called hybrid nickel leaching circuit that encompasses pressure acid leaching (PAL) and atmospheric leaching (AL) processes has made processing of low-grade ores (with nickel content as low as 0.5%) a possibility. However, significant challenges exist in lowering the operating costs for this new process including the reduction of sulphuric acid and the energy required to heat the pulp to the desired temperature (250oC). To address above challenges, a detailed understanding of the process chemistry together with interactions between unit operations feeding into and out of the system is required. To accomplish this, a software package with powerful convergence algorithms, control loops, background chemical equilibrium, aqueous thermodynamics and extensive databases containing information on the physical properties of desired components is needed. Using such a process simulator, it is possible to produce numerically rigorous mass/energy balances for as many variations of the model as desired. This allows enhanced analysis of the flowsheet, better process design, and ultimately, better business decisions. Although there have been several studies on hybrid circuit, most of these studies have only dealt with the effects of process variable such as temperature, acidity, pulp density. Thus far, no complete study has been published on the modelling of different proposed scenarios. The present work constitutes an effort towards bridging this gap. A number of possible flowsheeting combinations were simulated using a commercial software packages SysCAD, and some optimal configurations were identified.

scholarly journals Power generation from low grade waste heat using thermoelectric generator

2018 ◽  
Vol 64 ◽  
pp. 06005
Author(s):  
Rana Sohel ◽  
Iqbal Arbab ◽  
Date Abhijit ◽  
Akbarzadeh Aliakbar
Keyword(s):  
Mathematical Model ◽  
Power Generation ◽  
Heat Exchanger ◽  
Waste Heat ◽  
Electrical Power ◽  
Channel Length ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Low Grade ◽  
Optimum Flow Rate

Thermoelectric technology is thought to be a great solution in near future for producing electrical power and recovering low grade waste heat to cut the cost of power generation because of its consistency and eco-friendly affability. Though commercial accessibility of TEG is available currently but heat to electricity conversion efficiency is still low and cost of the module is reasonably high. It’s essential to use the modules competently which is strongly depends on suitable heat exchanger design and selection of proper operating conditions. In this work, TEG module has been selected from the commercially available modules with efficiency of 1.91% for the targeted low-grade waste heat temperature of Th=90°C and Tc=15°C which validated by experiment. Mathematical model has been proposed to simulate TEG based power generation system; the model can predict maximum net power, choose optimum operating conditions and dimensions of heat exchanger. Lab scale design with channel length 1 m, width 0.08 m and gap size 9 mm which is suitable for 50 TEG module (4 mm x 4 mm) have been simulated using proposed mathematical model. For above temperature range, predicted optimum net power was 76.45 W with optimum flow rate 0.94 L/s (56.4 L/min). This lab scale setup will be used for experimental validation of the proposed mathematical model. The obtained results from experiments and simulation are closely matched.

scholarly journals Efficiency of aluminum and iron electrodes in removal of colour, turbidity and total suspended solid from biologically treated municipal wastewater

2015 ◽  
Vol 7 (2) ◽  
pp. 799-805
Author(s):  
Arun Kumar Sharma ◽  
A.K. Chopra
Keyword(s):  
Municipal Wastewater ◽  
Operating Time ◽  
Total Suspended Solid ◽  
Suspended Solid ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Electrode Consumption ◽  
Electrode Combination ◽  
Initial Ph ◽  
Treated Municipal Wastewater

The present investigation was undertaken to observe the effect of different combinations of aluminium and iron (Al-Al, Al-Fe, Fe-Fe and Fe-Al) electrodes on the removal of colour, turbidity (TD) and total suspended solids (TSS) of biologically treated municipal wastewater ( BTMW) using applied potential (V), operating time (OT) and initial pH. The maximum removal of colour (98.7 %) and TSS (96.89 %) was found with the use of Al-Al combination with optimum operating conditions (Voltage: 40 V; OT: 40 mins.; IED: 1.0 cm; EA: 160 cm2; initial pH: 7.5 and ST: 30 mins). It was interesting to note that TD of BTMW was completely removed at these optimal operating conditions. The economic evaluation of electrode combinations was observed to be in the order of Fe-Al (1.17 US $/m3)> Al-Fe (1.11 US $/m3)> Fe-Fe (1.08 US $/m3) >Al-Al (1.01 US $/m3) in terms of energy and electrode consumption. Thus, the BTMW can be effectively treated with the Al-Al electrode combination in comparison to other electrode combinations (Al-Fe , Fe-Fe and Fe-Al).

scholarly journals Removal of arsenate by electrocoagulation reactor using aluminum ball anode electrodes

2018 ◽  
Vol 13 (4) ◽  
pp. 753-763 ◽  
Author(s):  
A. Y. Gören ◽  
M. S. Öncel ◽  
E. Demirbas ◽  
E. Şık ◽  
M. Kobya
Keyword(s):  
Removal Efficiency ◽  
Operating Time ◽  
Operating Conditions ◽  
Column Height ◽  
Quadratic Model ◽  
Optimum Operating ◽  
Airflow Rate ◽  
Statistical Experimental Design ◽  
Applied Current ◽  
Initial Ph

Abstract The aim of this research was to remove arsenate (As(V)) from groundwater using an air-injected electrocoagulation (EC) reactor with aluminum (Al) ball anodes. The effects of seven operating variables – initial pH, applied current (i), operating time (tEC), initial As(V) concentration (Co), Al ball anode diameter (dp), reactor column height (h), and airflow rate (Qair) were investigated with a Box-Behnken statistical experimental design. ANOVA results from the quadratic model equations indicated that the model fitted very well with the experimental data for the responses, which were removal efficiency, operating cost (OC), As(V) adsorption capacity, and effluent concentration (R2 ≥ 0.87). The most effective parameters were applied current, operating time, and anode height for As(V) removal efficiency in the EC reactor, while initial pH, Al anode diameter, and air flow rate had limited effect on removal. The model predicted a residual As(V) concentration below 10 μg/L under the optimum operating conditions (pH 7.03, 0.29 A, 10.5 min, dp 7.5 mm, 613.4 μg/L, h 5.1 cm, and Qair 6.4 L/min). The maximum As(V) removal efficiency and minimum OC in the EC process were almost 99% and 0.442 $/m3, respectively.

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