Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Extraction of Potassium from Potash Feldspar Ores with Sodium Chloride

PENG Qing-jing,ZOU Xiao-yong,HUANG Cheng,

过程工程学报 , 2002,
Abstract: The main factors that affect the leaching rate of potassium in potash feldspar were studied. It is shown that the best reaction conditions are reaction temperature of 890~950oC, size of potash feldspar ores below 0.208 mm, and the weight ratio of sodium chloride to potash feldspar ores being 1. The study showed that the leaching process is controlled by the internal ionic diffusion of Na+ and K+ in potash feldspar. The relations between diffusion coefficient and reaction temperature is expressed by the Arrhenius formula: Deff=D0exp(Ea/RT), with Ea = 81.42 kJ/mol, D0=0.324 mm2/h.
Experimental Research of the Synthesizing of 13X Molecular Sieves from Potash Feldspar Ores

TAO Hong,MA Hong-Wen,

无机材料学报 , 2001,
Abstract: X molecular sieve was synthesized from potash feldspar ores by baking and hydrothermal synthesizing procedures. The optimal technological parameters were determined by means of quadrature experiment. The properties of the synthesis powder such as XRD, crystal constants, SEM, DTA, chemical composition, SiO2/Al2O3 are similar to those of the ideal 13X moleclar sieve. And its absorbability comes up to the state standards of chemical industry of China.
Study on slime-containing potash ores flotation separate technic

Cheng Fangqin,Zhao Zhonghe,Ma Jinyuan,Li Da,Jiao Yong,

环境工程学报 , 2011,
Abstract: The slime-containing potash ores of Qinghai salt lake were studied from two aspects, properties of potash ore and flotation desliming technic, properties of potash ore and flotation desliming technic. The chemical compositions and structural characteristics of the slime-containing potash ores were determined by X-ray fluorescence spectrometry, X-ray diffraction analysis and scanning electron microscope. Factors which influence the desliming of potash ores by flotation were investigated. In the flotation, octadecylamine and kerosene were selected as floating agents. The results showed that more than 70% of the slimes were aluminium silicates which contained feldspar, caly, silty, calcium salt, etc. Most of slimes fill among the crystal particles of salt minerals or exist in micro-film structure. Slimes have high affinity for amine collectors, but they are badly flotated by octadecylamine (the flotation efficient was less than 1%). In the saturated brine, the desliming efficient of potash ores containing 20%~50% insolubles by kerosene was higher than 50%. This study can provide a powerful technical support for low grade potassium resource utilization.
Recovery of Copper from Copper Sulfide Concentrate by Sulfation Roasting  [PDF]
Yaming Zhao, Yanan Hou, Yuguo Cui, Hongwei Liang, Luanning Li
International Journal of Nonferrous Metallurgy (IJNM) , 2015, DOI: 10.4236/ijnm.2015.42002
Abstract: Sulfation roasting was studied to extract copper from the copper sulfide concentrate. Sodium sulfite was added as sulfation agent to the copper sulfide concentrate during roasting in this study. Sulfur removal rate at different roasting temperatures was investigated, and the effects of roasting temperature, roasting time, and the amount of sodium sulfite on copper extraction were studied. Copper extraction higher than 96% was achieved at optimum roasting conditions.
Luminescence Characteristics of Feldspar from Nigeria  [PDF]
Janet A. Ademola
Natural Science (NS) , 2014, DOI: 10.4236/ns.2014.612094

The luminescence characteristics of feldspar from Nigeria were investigated. Without preheat treatment, the TL glow curve exhibited two peaks at 136°C and 175°C. When preheated to a temperature of 200°C only one peak was observed at 240°C. The highest net IRSL intensity was obtained for a stimulation temperature of 250°C. The TL signal is reduced by IR stimulation, and the longer the stimulation the more pronounced the effect. The dose response curves for both the TL and the IRSL showed a linear relationship for the doses considered in the study. Dose recovery test performed using the SAR method showed consistency with given dose for both TL and IRSL.

Effect of roasting on the aflatoxin contents of Nigerian peanut seeds
BM Ogunsanwo, OOP Faboya, OR Idowu, OS Lawal, SA Bankole
African Journal of Biotechnology , 2004,
Abstract: Peanut seeds were prepared with variations in roasting conditions. Positive correlations were obtained between loss of aflatoxins in the products and the roasting conditions. Seeds dry- roasted at 140OC for 40 min resulted in 58.8% and 64.5% reductions in AFB1 and AFG1, those roasted at 1500C for 25 minutes resulted in 68.5% and 73.3% reductions in AFB1 and AFG1, respectively. Roasting at150OC for 30mins led to 70.0% and 79.8% reductions in AFB1 and AFG1 respectively. Key Words: Peanut, aflatoxin, roasting. African Journal of Biotechnology Vol.3(9) 2004:451-455
Changes of physical properties of coffee beans during roasting
Jokanovi? Marija R.,D?ini? Natalija R.,Cvetkovi? Biljana R.,Gruji? Slavica
Acta Periodica Technologica , 2012, DOI: 10.2298/apt1243021j
Abstract: The effects of heating time on physical changes (weight, volume, texture and colour) of coffee beans (Outspan and Guaxupe coffee) were investigated. The roasting temperature of both samples was 170°C and samples for analysis were taken at the intervals of 7 minutes during 40 minutes of roasting. Total weight loss at the end of the roasting process was 14.43 % (light roasted) and 17.15 % (medium to dark roasted) for Outspan and Guaxupe coffee beans, respectively. Significant (P < 0.05) changes in the coffee bean breaking force values were noted between the 7th and 14th minutes, and statistically not significant (P > 0.05) between the 35th and 40th minutes of the roasting. According to the L* colour parameter as a criterion for the classification of roasted coffee colour (light, medium, dark), the Outspan sample was medium and Guaxupe sample was dark roasted.
Simultaneous mineralization of CO2 and recovery of soluble potassium using earth-abundant potassium feldspar
HePing Xie,YuFei Wang,Yang Ju,Bin Liang,JiaHua Zhu,Ru Zhang,LingZhi Xie,Tao Liu,XiangGe Zhou,HongMei Zeng,Chun Li,HouFang Lu
Chinese Science Bulletin , 2013, DOI: 10.1007/s11434-012-5466-7
Abstract: CO2 capture and storage (CCS) is an important strategy in combatting anthropogenic climate change. However, commercial application of the CCS technique is currently hampered by its high energy expenditure and costs. To overcome this issue, CO2 capture and utilization (CCU) is a promising CO2 disposal method. We, for the first time, developed a promising method to mineralize CO2 using earth-abundant potassium feldspar in order to effectively reduce CO2 emissions. Our experiments demonstrate that, after adding calcium chloride hexahydrate as an additive, the K-feldspar can be transformed to Ca-silicates at 800°C, which can easily mineralize CO2 to form stable calcium carbonate and recover soluble potassium. The conversion of this process reached 84.7%. With further study, the pretreatment temperature can be reduced to 250°C using hydrothermal method by adding the solution of triethanolamine (TEA). The highest conversion can be reached 40.1%. The process of simultaneous mineralization of CO2 and recovery of soluble potassium can be easily implemented in practice and may provide an economically feasible way to tackle global anthropogenic climate change.
Comparison of the mechanisms of microwave roasting and conventional roasting and of their effects on vanadium extraction from stone coal  [PDF]
Yi-zhong Yuan,Yi-min Zhang,Tao Liu,Tie-jun Chen
- , 2015, DOI: https://doi.org/10.1007/s12613-015-1096-9
Abstract: Experiments comparing microwave blank roasting and conventional blank roasting for typical vanadium-bearing stone coal from Hubei Province in central China, in which vanadium is present in muscovite, were conducted to investigate the effects of roasting temperature, roasting time, H2SO4 concentration, and leaching time on vanadium extraction. The results show that the vanadium leaching efficiency is 84% when the sample is roasted at 800°C for 30 min by microwave irradiation and the H2SO4 concentration, liquid/solid ratio, leaching temperature, and leaching time are set as 20vol%, 1.5:1 mL·g?1, 95°C, and 8 h, respectively. However, the vanadium leaching efficiency achieved for the sample subjected to conventional roasting at 900°C for 60 min is just 71% under the same leaching conditions. Scanning electron microscopy (SEM) analysis shows that the microwave roasted samples contain more cracks and that the particles are more porous compared to the conventionally roasted samples. According to the results of X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) analyses, neither of these roasting methods could completely destroy the mica lattice structure under the experimental conditions; however, both methods deformed the muscovite structure and facilitated the leaching process. Comparing with conventional roasting, microwave roasting causes a greater deformation of the mineral structure at a lower temperature for a shorter roasting time.
Assessment of Combustion and Potash Production as Options for Management of Wood Waste
J Babayemi, G Adewuyi
Journal of Applied Sciences and Environmental Management , 2010,
Abstract: This study assessed combustion and potash production as options for management of wood waste. The percentage reduction in volume by combustion and potash generation potential of wood waste from nine different common species of wood obtained from a wood factory in Ibadan were evaluated. Potash from the ashes was extracted with distilled water through a system of filtration. The amount of ash, in kilogram per cubic metre of saw dust, and the amount of potash, in kilogram per cubic metre of ash and kilogram per cubic metre of saw dust were determined. The volume of sawdust was reduced by 95% after combustion. The ash generated ranged between 1.42 – 15.18 Kg/m3; potash yield ranged between 4.74 – 53.76 Kg/m3 of ashes and 0.21 – 1.53 Kg/m3 of saw dust.
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.