scholarly journals A New Collector for Effectively Increasing Recovery in Copper Oxide Ore-Staged Flotation

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 595
Author(s):  
Renfeng Zhu ◽  
Guohua Gu ◽  
Zhixiang Chen ◽  
Yanhong Wang ◽  
Siyu Song
Keyword(s):  
Particle Size ◽  
Copper Oxide ◽  
High Efficiency ◽  
Average Particle Size ◽  
Economic Feasibility ◽  
Processing Plant ◽  
Average Particle ◽  
Entrainment Rate ◽  
Flotation Process ◽  
New Type

A new method, staged flotation for effectively increasing the recovery of ultra-fine copper oxide ore with a new type of collector (ZH-1, C3-5 carbon chain xanthate) is proposed for the first time. The flotation process and mechanism were examined by flotation tests, entrainment rate analysis, laser particle size experiments and microscopic imagery as well as economic feasibility analysis. It was demonstrated that the collector isoamyl sodium xanthate (ISX) shows a good collection ability (recovery exceeded 95%) for azurite, but the recovery was relatively much lower for malachite (only near 80%) due to the different particle size distribution. The new type of xanthate ZH-1 has shown a high-efficiency collection performance for fine-grained malachite. The recovery achieved for −10 μm malachite was more than 95% when the ZH-1 dosage was 150 mg/L, while the average particle size of −10 μm malachite sharply increased from 4.641 μm to 9.631 μm. The batch flotation results indicated that the copper oxide flotation recovery increased from 79.67% to 83.38%, and the grade also raised from 18.08% to 18.14% after using the staged flotation technology with ZH-1 as collector during the flotation of −25 μm ore. It was confirmed that this technology was quite effective for the recovery of copper oxide at the Dishui Copper Processing Plant, which successfully increased its gross profit by 1.6 million US$ per year.

PENGARUH LAJU PREKURSOR SERBUK ALUMINIUM TERHADAP BENTUK MORFOLOGI NANOPARTIKEL ALUMINA DENGAN METODE THERMAL PLASMA

ROTOR ◽  
2017 ◽  
Vol 10 (1) ◽  
pp. 17
Author(s):  
Havid Arifian Rochman ◽  
Arief Ginanjar Dirgantara ◽  
Salahudin Junus ◽  
Imam Sholahuddin ◽  
Aris Zainul Muttaqin
Keyword(s):  
Particle Size ◽  
Aluminum Powder ◽  
Thermal Plasma ◽  
High Efficiency ◽  
Average Particle Size ◽  
Alumina Nanoparticles ◽  
Rate Variation ◽  
Average Particle ◽  
Dc Plasma ◽  
Simple Method

The synthesis of nanoparticles using thermal DC plasma method is a simple method for ease of installation and high efficiency is due to the rate of precursor that can be controlled. Micro-sized aluminum powder is synthesized using thermal DC plasma undergoing a process of evaporation as it passes through high temperature plasma flame, where kemuadian oxidized aluminum particles which evaporates the particles are split and binds with oxygen to form aluminum oxide or also known as alumina (Al2O3). In this experiment, the flow rate of oxygen plasma parameters at 35 SCFH (Standard Cubic Feet per Hour) and 20 amperes flows with precursors rate variation of 1.16 g / min, 3.19 g / min, and 3.5 g / min. Precursors used is 88 micro sized aluminum powder. To determine the morphology of nanoparticles of alumina testing scanning electron microscopy (SEM), the morphology form of nanosphere. Results of the analysis showed that the rate of precursor low causing agglomeration level slightly while the higher rate of precursor agglomeration rate also increased. At the rate of precursor 1.16 g / min, nanoparikel undergo agglomeration with an average particle size of 36.55 nm, and then at a rate of 3.19 gr precursor / mnt an average particle size of 46.49 nm, and at a rate of 3.5 gr / mnt an average particle size of 46.49 nm. The powder nanoparticles were then characterized using X-ray defraksi (XRD) where all alumina nanoparticles were synthesized showed alumina phase that is formed is a phase δ-Al2O3. Keywords: Alumina nanoparticles, DC Thermal Plasma, morphology, precursor rate, nanoparticles size, SEM, XRD.

scholarly journals Characterisation and Optical Studies of Copper Oxide Nanostructures Doped with Lanthanum Ions

2014 ◽  
Vol 14 (4) ◽  
pp. 49-60 ◽  
Author(s):  
G. Varughese ◽  
V. Rini ◽  
S.P. Suraj ◽  
K.T. Usha
Keyword(s):  
Particle Size ◽  
Copper Oxide ◽  
Average Particle Size ◽  
Band Gap Energy ◽  
Average Particle ◽  
Nano Materials ◽  
Chemical Route ◽  
Direct Band ◽  
Gap States ◽  
La Doped

AbstractCopper Oxide is an extensively studied group II-VI semiconductor with optical properties. It exhibits a wide variety of morphologies in the nano regime that can be grown by tuning the growth habit of the CuO crystal. CuO nano materials with an average particle size of 15-27 nm are synthesized by chemical route. XRD, SEM, FTIR UV-Vis and EDS characterize the samples. The percentage of doping material is confirmed from the EDS spectra. The average crystal size of the prepared CuO: La nanopowder is determined by XRD. The UV absorption spectra revealed the absorption edge at wavelength 389 nm indicating the smaller size of CuO:La nano particle. The optical direct band gap energy of doped CuO nanoparticle is found to be in the range 3.149 eV. The increasing red shift with decreasing particle size suggests that the defects responsible for the intra gap states are primarily surface defect. The La doped CuO is highly effective and can significantly enhance the photo catalytic degradation.

Preparation and Characterization of Silicone Oil/UF Resin Microcapsules as Erosion Inhibitor

2016 ◽  
Vol 723 ◽  
pp. 481-485 ◽  
Author(s):  
Hong Guang Li ◽  
Shao Sen Lin ◽  
Shi Guo Du ◽  
De Jiang Lin
Keyword(s):  
Particle Size ◽  
High Efficiency ◽  
In Situ Polymerization ◽  
Silicone Oil ◽  
Average Particle Size ◽  
Weight Ratio ◽  
Polymerization Process ◽  
Core Material ◽  
Molar Ratio ◽  
Average Particle

Microcapsules with silicone oil as core and poly (urea-formaldehyde) as shell were prepared by direct in-situ polymerization process. The influences of formaldehyde-urea molar ratios on microcapsules morphologies were investigated by scanning electron microscope (SEM). The microcapsules were characterized by fourier transform infrared spectrometer (FT-IR), particle size analyzer, simultaneous thermal analyzer. The results showed that well dispersive microcapsules were obtained with average particle size of 2.5 μm when formaldehyde-urea molar ratio was 1.8:1.0 and that the weight ratio of silicon dioxide to microcapsule was 15.4%, which produced from pyrolysis of core material silicone oil. The prepared microcapsules were expected to a kind of high-efficiency erosion inhibitor when used in propellant.

A Study on Novel Gas Atomization Device for Preparing Ultra Fine Metal Powder

2011 ◽  
Vol 291-294 ◽  
pp. 741-744
Author(s):  
Xin An Dang ◽  
Li Li Wang ◽  
Li Jun Yang
Keyword(s):  
Particle Size ◽  
Magnetic Particles ◽  
High Efficiency ◽  
Surface Effect ◽  
Average Particle Size ◽  
Average Particle ◽  
Good Prospect ◽  
Gas Atomization ◽  
Metal Powders ◽  
Two Fluids

On the basis of technologies of gas atomization, supersonic gas atomization, surface effect of electric charge and jet, we design a new-style device of two fluids atomization with the combination of solid atomization and electric field utilizing a LAVAL nozzle, a delivery tube of sectional type and the electrical field dispersion technique. The soldering tin of 63 A was atomized with the air, and the powder prepared was analyzed by optical granularity analyzer, nanometer magnetic particles and Zeta potential analyzer. The results show that the particle size with less than 8μm can reach 75%; the average particle size is 1.7612μm, and the first peak in the distribution curve is about 500 nm, which is an order of magnitude smaller than that the existing reported peak. The compound atomization device can refine the particle size of powers effectively, improve uniformity, yielding rate, and the purity of atomized powders and has a significant effect on atomizing, thus provides powerful supports for preparing ultra fine metal powders with high efficiency and low energy consumption and has a good prospect in application.

The Leaching of Copper Oxide Ore in Ammonium Chloride Solution

2014 ◽  
Vol 675-677 ◽  
pp. 1459-1462 ◽  
Author(s):  
Hua Sheng Dong ◽  
Jing Yang
Keyword(s):  
Particle Size ◽  
Copper Oxide ◽  
Ammonium Chloride ◽  
Chloride Solution ◽  
Average Particle Size ◽  
Ammonium Chloride Solution ◽  
Solution Temperature ◽  
Copper Extraction ◽  
Average Particle ◽  
Effect Of Copper

In this study, the leaching effect of copper oxide ore was investigated using ammonium chloride solution as leaching agent. The effects of temperature, concentration of ammonium chloride, average particle size and stirring speed on the leaching of copper oxide ore were investigated. The leaching rate increased with increasing solution temperature, concentration, and stirring speed as well as with decreasing average particle size. Ammonium chloride solution can therefore be used as an effective leaching agent for copper extraction from copper oxide ore.

Determination of grinding parameters of fenugreek seed

1970 ◽  
Vol 26 (1) ◽  
pp. 16 ◽  
Author(s):  
S Balasubramanian ◽  
Rajkumar Rajkumar ◽  
K K Singh
Keyword(s):  
Particle Size ◽  
Energy Consumption ◽  
Moisture Content ◽  
Specific Energy ◽  
Feed Rate ◽  
Average Particle Size ◽  
Specific Energy Consumption ◽  
Average Particle ◽  
Fenugreek Seeds ◽  
Fenugreek Seed

Experiment to identify ambient grinding conditions and energy consumed was conducted for fenugreek. Fenugreek seeds at three moisture content (5.1%, 11.5% and 17.3%, d.b.) were ground using a micro pulverizer hammer mill with different grinding screen openings (0.5, 1.0 and 1.5 mm) and feed rate (8, 16 and 24 kg h-1) at 3000 rpm. Physical properties of fenugreek seeds were also determined. Specific energy consumptions were found to decrease from 204.67 to 23.09 kJ kg-1 for increasing levels of feed rate and grinder screen openings. On the other hand specific energy consumption increased with increasing moisture content. The highest specific energy consumption was recorded for 17.3% moisture content and 8 kg h-1 feed rate with 0.5 mm screen opening. Average particle size decreased from 1.06 to 0.39 mm with increase of moisture content and grinder screen opening. It has been observed that the average particle size was minimum at 0.5 mm screen opening and 8 kg h-1 feed rate at lower moisture content. Bond’s work index and Kick’s constant were found to increase from 8.97 to 950.92 kWh kg-1 and 0.932 to 78.851 kWh kg-1 with the increase of moisture content, feed rate and grinder screen opening, respectively. Size reduction ratio and grinding effectiveness of fenugreek seed were found to decrease from 4.11 to 1.61 and 0.0118 to 0.0018 with the increase of moisture content, feed rate and grinder screen opening, respectively. The loose and compact bulk densities varied from 219.2 to 719.4 kg m-3 and 137.3 to 736.2 kg m-3, respectively.  

Formulating SLN and NLC as Innovative Drug Delivery Systems for Non-Invasive Routes of Drug Administration

2020 ◽  
Vol 27 (22) ◽  
pp. 3623-3656 ◽  
Author(s):  
Bruno Fonseca-Santos ◽  
Patrícia Bento Silva ◽  
Roberta Balansin Rigon ◽  
Mariana Rillo Sato ◽  
Marlus Chorilli
Keyword(s):  
Drug Delivery ◽  
Particle Size ◽  
Drug Release ◽  
Drug Loading ◽  
Average Particle Size ◽  
Delivery Systems ◽  
Average Particle ◽  
Minor Importance ◽  
Routes Of Administration ◽  
Non Invasive

Colloidal carriers diverge depending on their composition, ability to incorporate drugs and applicability, but the common feature is the small average particle size. Among the carriers with the potential nanostructured drug delivery application there are SLN and NLC. These nanostructured systems consist of complex lipids and highly purified mixtures of glycerides having varying particle size. Also, these systems have shown physical stability, protection capacity of unstable drugs, release control ability, excellent tolerability, possibility of vectorization, and no reported production problems related to large-scale. Several production procedures can be applied to achieve high association efficiency between the bioactive and the carrier, depending on the physicochemical properties of both, as well as on the production procedure applied. The whole set of unique advantages such as enhanced drug loading capacity, prevention of drug expulsion, leads to more flexibility for modulation of drug release and makes Lipid-based nanocarriers (LNCs) versatile delivery system for various routes of administration. The route of administration has a significant impact on the therapeutic outcome of a drug. Thus, the non-invasive routes, which were of minor importance as parts of drug delivery in the past, have assumed added importance drugs, proteins, peptides and biopharmaceuticals drug delivery and these include nasal, buccal, vaginal and transdermal routes. The objective of this paper is to present the state of the art concerning the application of the lipid nanocarriers designated for non-invasive routes of administration. In this manner, this review presents an innovative technological platform to develop nanostructured delivery systems with great versatility of application in non-invasive routes of administration and targeting drug release.

Azithromycin nanosuspension preparation using evaporative precipitation into aqueous solution (EPAS) method and its comparative dissolution study

2020 ◽  
Vol 17 ◽  
Author(s):  
Mohammad Hossain Shariare ◽  
Tonmoy Kumar Mondal ◽  
Hani Alothaid ◽  
Md. Didaruzzaman Sohel ◽  
MD Wadud ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Dissolution Rate ◽  
Average Particle Size ◽  
Scale Up ◽  
Average Particle ◽  
Total Drug ◽  
Residual Solvent ◽  
Dissolution Study ◽  
Drug Content

Aim: EPAS (evaporative precipitation into aqueous solution) was used in the current studies to prepare azithromycin nanosuspensions and investigate the physicochemical characteristics for the nanosuspension batches with the aim of enhancing the dissolution rate of the nanopreparation to improve bioavailability. Methods: EPAS method used in this study for preparing azithromycin nanosuspension was achieved through developing an in-house instrumentation method. Particle size distribution was measured using Zetasizer Nano S without sample dilution. Dissolved azithromycin nanosuspensions were also compared with raw azithromycin powder and commercially available products. Total drug content of nanosuspension batches were measured using an Ultra-Performance Liquid Chromatography (UPLC) system with Photodiode Array (PDA) detector while residual solvent was measured using gas chromatography (GC). Results: The average particle size of azithromycin nanosuspension was 447.2 nm and total drug content was measured to be 97.81% upon recovery. Dissolution study data showed significant increase in dissolution rate for nanosuspension batch when compared to raw azithromycin and commercial version (microsuspension). The residual solvent found for azithromycin nanosuspension is 0.000098023 mg/ mL or 98.023 ppb. Conclusion: EPAS was successfully used to prepare azithromycin nanoparticles that exhibited significantly enhanced dissolution rate. Further studies are required to scale up the process and determine long term stability of the nanoparticles.

scholarly journals Evaluation of the Effects of Filler Fineness on the Properties of an Epoxy Asphalt Mixture

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2003
Author(s):  
Wei Xu ◽  
Jintao Wei ◽  
Zhengxiong Chen ◽  
Feng Wang ◽  
Jian Zhao
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
Asphalt Mixture ◽  
Average Particle ◽  
Fine Dust ◽  
Bonding Structure ◽  
Epoxy Asphalt ◽  
Mineral Powder ◽  
Marshall Stability ◽  
Mixture Sample

The type and fineness of a filler significantly affect the performance of an asphalt mixture. There is a lack of specific research on the effects of filler fineness and dust from aggregates on the properties of epoxy asphalt (EA) mixtures. The effects of aggregate dust and mineral powder on the properties of an EA mixture were evaluated. These filler were tested to determine their fineness, specific surface area and mineral composition. The effects of these fillers on the EA mastic sample and mixture were evaluated. The morphology of the EA mastic samples was analyzed using scanning electron microscopy (SEM). The effects of the fillers on the Marshall stability, tensile strength and fatigue performance of the EA mixture were evaluated. The dust from the aggregates exhibited an even particle size distribution, and its average particle size was approximately 20% of that of the mineral powder. The SEM microanalysis showed that the EA mastic sample containing relatively fine dust formed a tight and dense interfacial bonding structure with the aggregate. The EA mixture sample containing filler composed of dust from aggregate had a significantly higher strength and longer fatigue life than that of the EA sample containing filler composed of mineral powder.

scholarly journals Surface Activity of Humic Acid and Its Sub-Fractions from Forest Soil

2021 ◽  
Vol 13 (15) ◽  
pp. 8122
Author(s):  
Shijie Tian ◽  
Weiqiang Tan ◽  
Xinyuan Wang ◽  
Tingting Li ◽  
Fanhao Song ◽  
...  
Keyword(s):  
Surface Tension ◽  
Particle Size ◽  
Humic Acid ◽  
Forest Soil ◽  
Surface Activity ◽  
Self Assembly ◽  
Average Particle Size ◽  
Gaussian Model ◽  
Exponential Model ◽  
Average Particle

Surface activity of humic acid (HA) and its six sub-fractions isolated from forest soil were characterized by surface tension measurements, dynamic light scattering, and laser doppler electrophoresis. The surface tension of HA and its sub-fractions reduced from 72.4 mN·m−1 to 36.8 mN·m−1 in exponential model with the increasing concentration from 0 to 2000 mg·L−1. The critical micelle concentration (CMC) and Z-average particle size ranged from 216–1024 mg·L−1 and 108.2–186.9 nm for HA and its sub-fractions, respectively. The CMC have related with alkyl C, O-alkyl C, aromatic C, and carbonyl C (p < 0.05), respectively, and could be predicted with the multiple linear regression equation of CMC, CMC = 18896 − 6.9 × C-296 × alkyl C-331 × aromatic C-17019 × H/C + 4054 × HB/HI (p < 0.05). The maximum particle size was 5000 nm after filtered by a membrane with pore size of 450 nm, indicating HA and its sub-fractions could progressed self-assembly at pH 6.86. The aggregate sizes of number-base particle size distributions were mainly in six clusters including 2 ± 1 nm, 5 ± 2 nm, 10 ± 3 nm, 21 ± 8 nm, 40 ± 10 nm, and >50 nm analyzed by Gaussian model that maybe due to the inconsistency of the components and structures of the HA sub-fractions, requiring further study. It is significance to explore the surface activity of HA and its sub-fractions, which is helpful to clarify the environmental behavior of HA.

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