Removal of Fluorides and Chlorides from Zinc Oxide Fumes by Microwave Sulfating Roasting

AbstractDechlorination and defluorination from zinc oxide dust by microwave sulfating roasting was investigated in this study. According to proposed reactions in the process, detailed experiments were systematically conducted to study the effect of roasting temperature, holding time, air and steam flow rates on the efficiency of the removal of F and Cl. The results show that 92.3% of F and 90.5% of Cl in the fume could be purified when the condition of the roasting temperature of 650 °C, holding time at 60 min, air flow of 300 L/h and steam flow of 8 ml/min was optimized. Our investigation indicates that microwave sulfating roasting could be a promising new way for the dechlorination and defluorination from zinc oxide dust.

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Dechlorination of Zinc Oxide Dust from Waelz Kiln by Microwave Roasting

High Temperature Materials and Processes ◽

10.1515/htmp-2013-0131 ◽

2015 ◽

Vol 34 (3) ◽

Cited By ~ 2

Author(s):

Zhiqiang Li ◽

Libo Zhang ◽

Aiyuan Ma ◽

Jinhui Peng ◽

Jing Li ◽

...

Keyword(s):

Zinc Oxide ◽

Thermodynamic Analysis ◽

New Technology ◽

Air Flow ◽

Holding Time ◽

Microwave Roasting ◽

Selective Heating ◽

Roasting Temperature ◽

Influencing Parameters ◽

Waelz Kiln

AbstractThe new technology of dechlorination from zinc oxide dust by microwave roasting was investigated, combined with the advantages of microwave selective heating and based on a thermodynamic analysis of zinc and lead halides. The associated dechlorination reactions were discussed in details and the effect of all the influencing parameters such as roasting temperature, holding time, stirring speed and air flow were systematically investigated. Experimental results showed that zinc oxide dust dechlorination rate could reach over 95% and meet the requirements of wet smelting electrolysis, given an air flow of 300 L/h, a stirring speed of 60 r/min, a roasting temperature of 650 °C and a holding time of 30 min. Microwave roasting provided a new solution to the dechlorination from zinc oxide dust.

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Processing Dross from Hot-Dip Galvanizing by Chlorination Roasting

Sustainability ◽

10.3390/su132212530 ◽

2021 ◽

Vol 13 (22) ◽

pp. 12530

Author(s):

Nurlan Kalievich Dosmukhamedov ◽

Arkady Kaplan ◽

Erzhan Esenbaiuly Zholdasbay ◽

Gulzada Myngyshkyzy Koishina ◽

Yeleussiz Bolatovich Tazhiev ◽

...

Keyword(s):

Zinc Oxide ◽

Air Flow ◽

Poultry Feed ◽

Initial Amount ◽

Pure Zinc ◽

Feed Material ◽

Lead And Cadmium ◽

Roasting Temperature ◽

Chlorination Roasting ◽

Mineral Additives

Dross from hot-dip galvanizing is an important source of pure zinc ingots and zinc oxide for use as mineral additives in animal and poultry feed. Thermodynamic calculations have shown the possibility of solving the issue of dross processing by roasting using CaCl2 and NH4Cl. The influence of the consumption of chlorinating reagents, the roasting temperature on the degree of sublimation of Pb, Fe, Ni, Cu and Cd has been investigated. It has been shown that the best results are achieved when roasting the dross with the simultaneous use of CaCl2 and NH4Cl in amounts of 6 and 15% by weight of the feed material. The optimal roasting parameters were established: T = 1000 °C, duration—60 min, air flow—0.1 L/min. Recovered pure zinc oxide composition (%) was: 0.05 Pb, 0.15 Fe, 0.06 Ni, 0.003 Cu and 0.001 Cd. The degree of sublimation of copper, nickel and iron chlorides was ~75%, with lead and cadmium at 90–98% of their initial amount in the dross.

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Nitrogen Removal from Anaerobically-Treated Leachate

Water Quality Research Journal ◽

10.2166/wqrj.1984.008 ◽

1984 ◽

Vol 19 (1) ◽

pp. 87-100

Author(s):

D. Prasad ◽

J.G. Henry ◽

P. Elefsiniotis

Keyword(s):

Nitrogen Removal ◽

Air Flow ◽

Operating Conditions ◽

Air Flow Rate ◽

Flow Rates ◽

Anaerobic Filter ◽

Ph Values ◽

Wide Range ◽

Ammonia Desorption ◽

Effects Of Ph

Abstract Laboratory studies were conducted to demonstrate the effectiveness of diffused aeration for the removal of ammonia from the effluent of an anaerobic filter treating leachate. The effects of pH, temperature and air flow on the process were studied. The coefficient of desorption of ammonia, KD for the anaerobic filter effluent (TKN 75 mg/L with NH3-N 88%) was determined at pH values of 9, 10 and 11, temperatures of 10, 15, 20, 30 and 35°C, and air flow rates of 50, 120, and 190 cm3/sec/L. Results indicated that nitrogen removal from the effluent of anaerobic filters by ammonia desorption was feasible. Removals exceeding 90% were obtained with 8 hours aeration at pH of 10, a temperature of 20°C, and an air flow rate of 190 cm3/sec/L. Ammonia desorption coefficients, KD, determined at other temperatures and air flow rates can be used to predict ammonia removals under a wide range of operating conditions.

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Geometrical Optimization of a Venturi-Type Microbubble Generator Using CFD Simulation and Experimental Measurements

Designs ◽

10.3390/designs5010004 ◽

2021 ◽

Vol 5 (1) ◽

pp. 4

Author(s):

Dillon Alexander Wilson ◽

Kul Pun ◽

Poo Balan Ganesan ◽

Faik Hamad

Keyword(s):

Water Flow ◽

Flow Rate ◽

Cfd Simulation ◽

Air Flow ◽

Bubble Diameter ◽

Diameter Ratio ◽

Experimental Measurements ◽

Cfd Model ◽

Flow Rates ◽

Throat Diameter

Microbubble generators are of considerable importance to a range of scientific fields from use in aquaculture and engineering to medical applications. This is due to the fact the amount of sea life in the water is proportional to the amount of oxygen in it. In this paper, experimental measurements and computational Fluid Dynamics (CFD) simulation are performed for three water flow rates and three with three different air flow rates. The experimental data presented in the paper are used to validate the CFD model. Then, the CFD model is used to study the effect of diverging angle and throat length/throat diameter ratio on the size of the microbubble produced by the Venturi-type microbubble generator. The experimental results showed that increasing water flow rate and reducing the air flow rate produces smaller microbubbles. The prediction from the CFD results indicated that throat length/throat diameter ratio and diffuser divergent angle have a small effect on bubble diameter distribution and average bubble diameter for the range of the throat water velocities used in this study.

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149 Evaluation of Hammermill Tip Speed, Air Assist, and Screen Hole Diameter on Ground Corn Characteristics

Journal of Animal Science ◽

10.1093/jas/skab054.227 ◽

2021 ◽

Vol 99 (Supplement_1) ◽

pp. 134-135

Author(s):

Michaela B Braun ◽

Kara M Dunmire ◽

Michael Sodak ◽

Jerry Shepherd ◽

Randy Fisher ◽

...

Keyword(s):

Particle Size ◽

Geometric Mean ◽

Air Flow ◽

Hole Diameter ◽

Experimental Unit ◽

Flow Index ◽

Air Flow Rate ◽

Flow Rates ◽

Composite Flow ◽

Ground Corn

Abstract This study was performed to evaluate hammermill tip speed, assistive airflow and screen hole diameter on hammermill throughput and characteristics of ground corn. Corn was ground using two Andritz hammermills (Model: 4330–6, Andritz Feed & Biofuel, Muncy,PA) measuring 1-m in diameter each equipped with 72 hammers and 300 HP motors. Treatments were arranged in a 3 × 3 × 3 factorial design with 3 tip speeds (3,774, 4,975, and 6,176 m/min), 3 screen hole diameters (2.3, 3.9 and 6.3 mm), and 3 air flow rates (1,062, 1,416, and 1,770 fan RPM). Corn was ground on 3 separate days to create 3 replications and treatments were randomized within day. Samples were collected and analyzed for moisture, particle size, and flowability characteristics. Data were analyzed using the GLIMMIX procedure of SAS 9.4 with grinding run serving as the experimental unit and day serving as the block. There was a 3-way interaction for standard deviation (Sgw), (linear screen hole diameter × linear hammer tip speed × linear air flow, P = 0.029). There was a screen hole diameter × hammer tip speed interaction (P < 0.001) for geometric mean particle size dgw (P < 0.001) and composite flow index (CFI) (P < 0.001). When tip speed increased from 3,774 to 6,176 m/min the rate of decrease in dgw was greater as screen hole diameter increased from 2.3 to 6.3 mm resulting in a 67, 111, and 254 µm decrease in dgw for corn ground using the 2.3, 3.9, and 6.3 mm screen hole diameter, respectively. For CFI, increasing tip speed decreased the CFI of ground corn when ground using the 3.9 and 6.3 mm screen. However, when grinding corn using the 2.3 mm screen, there was no evidence of difference in CFI when increasing tip speed. In conclusion, the air flow rate did not influence dgw of corn but hammer tip speed and screen size were altered and achieved a range of dgw from 304 to 617 µm.

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Evaluation of pressure coefficients and estimation of air flow rates in buildings employing wind towers

Solar Energy ◽

10.1016/0038-092x(86)90132-5 ◽

1986 ◽

Vol 37 (5) ◽

pp. 363-374 ◽

Cited By ~ 62

Author(s):

C. Karakatsanis ◽

M.N. Bahadori ◽

B.J. Vickery

Keyword(s):

Air Flow ◽

Flow Rates ◽

Pressure Coefficients

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Membrane air flow rates and HF sludging phenomenon in SMBR

Desalination ◽

10.1016/j.desal.2007.10.060 ◽

2009 ◽

Vol 236 (1-3) ◽

pp. 135-142 ◽

Cited By ~ 9

Author(s):

Julie Lebegue ◽

M. Heran ◽

A. Grasmick

Keyword(s):

Air Flow ◽

Flow Rates

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Model-Based Analysis of Transient Behavior of Large Scale CFB Boilers

17th International Conference on Fluidized Bed Combustion ◽

10.1115/fbc2003-130 ◽

2003 ◽

Cited By ~ 3

Author(s):

Ari Kettunen ◽

Timo Hyppa¨nen ◽

Ari-Pekka Kirkinen ◽

Esa Maikkola

Keyword(s):

Flow Rate ◽

Large Scale ◽

Air Flow ◽

Model Parameters ◽

Air Flow Rate ◽

Process Data ◽

Cfb Boiler ◽

Flow Rates ◽

Load Change ◽

Secondary Air

The main objective of this study was to investigate the load change capability and effect of the individual control variables, such as fuel, primary air and secondary air flow rates, on the dynamics of large-scale CFB boilers. The dynamics of the CFB process were examined by dynamic process tests and by simulation studies. A multi-faceted set of transient process tests were performed at a commercial 235 MWe CFB unit. Fuel reactivity and interaction between gas flow rates, solid concentration profiles and heat transfer were studied by step changes of the following controllable variables: fuel feed rate, primary air flow rate, secondary air flow rate and primary to secondary air flow ratio. Load change performance was tested using two different types of tests: open and closed loop load changes. A tailored dynamic simulator for the CFB boiler was built and fine-tuned by determining the model parameters and by validating the models of each process component against measured process data of the transient test program. The know-how about the boiler dynamics obtained from the model analysis and the developed CFB simulator were utilized in designing the control systems of three new 262 MWe CFB units, which are now under construction. Further, the simulator was applied for the control system development and transient analysis of the supercritical OTU CFB boiler.

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