scholarly journals Mechano-Activation and SHS of Difficultly Taken Ore

2014 ◽  
Vol 13 (3-4) ◽  
pp. 189
Author(s):  
O. Bayrakova ◽  
O. Golovchenko ◽  
S. Aknazarov
Keyword(s):  
Mechanical Activation ◽  
Chemical Activation ◽  
Leaching Rate ◽  
Optimal Conditions ◽  
Optimum Conditions ◽  
Activation Time ◽  
Technological Parameters ◽  
Leaching Process ◽  
Grinding Media ◽  
Refractory Ores

Technological parameters of opening refractory ores by mechanical activation which determine remaining and the morphology of the samples after mechanical activation, SHS synthesis and the leaching process has been defined. Mechano-chemical activation of arsenopirita in different modes increases process have been defined. Optimal conditions for activation: time - 30 min at a ratio of grinding media and mineral 2:1. Leaching rate was higher for the activated samples the same amount of time than the original. Extraction of gold for the chosen optimum conditions is 93.2-95 %.

Preparation of Activated Carbon from Waste Particle Board by Chemical Activation Using Potassium Hydroxide

2010 ◽  
Vol 129-131 ◽  
pp. 1151-1155 ◽  
Author(s):  
Xiao Juan Jin ◽  
Zhi Ming Yu ◽  
Zhe Ren ◽  
Xin Liu
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Potassium Hydroxide ◽  
Chemical Activation ◽  
Particle Board ◽  
Optimum Conditions ◽  
Activation Time ◽  
Activation Temperature ◽  
Methylene Blue Adsorption ◽  
Positive Effects

Activated carbons were prepared through chemical activation of waste particle board (WPB) precursor using potassium hydroxide as the chemical agent. The effects of different parameters, such as chemical/WPB ratio, activation time and activation temperature on yield and the methylene blue adsorption capacity of activated carbon were investigated. Experimental results indicated that the optimum conditions were as follow: activation temperature 850°C, KOH(50% concentration)/ WPB 4.0, activation time 50 min. Amount of methylene blue adsorption, Iodine number and the yield of activated carbon prepared under optimum conditions were 15.0 mL/0.lg, 1213mg/g and 36.9%, respectively. Therefore, great potential exists for developing activated carbon products from waste wood, which will have the positive effects of reducing our landfill problem and gain attractive products.

scholarly journals RESEARCH OF MECHANICAL ACTIVATION OF TECHNICAL HYDROLYSIS LIGNIN AS A COMPONENT OF FUEL BRIQUET

2020 ◽  
pp. 355-363
Author(s):  
Aleksandr Vasil'yevich Aleksandrov ◽  
Anastasiya Valer'yevna Afanasova ◽  
Anatoliy Pavlovich Rudenko
Keyword(s):  
Mechanical Activation ◽  
Lignin Content ◽  
Calorific Value ◽  
Joint Effect ◽  
Experiment Planning ◽  
Hydrolysis Lignin ◽  
Activation Time ◽  
Technological Parameters ◽  
Thermogravimetric Studies ◽  
Required Quality

The results of studies of changes in the fractional composition, calorific value and structure of lignin as a component of the fuel briquette as a result of mechanical activation based on the interpretation  of experimental research data are given in the article. Criteria for mechanical activation are proposed. To identify the joint effect of mechanical activation time and the proportion of technical in the composition of the briquette, the experiment planning method was applied. As a result of data processing, a regression equation was obtained for predicting the calorific value of briquettes from the lignin content and the time of its mechanical activation, and its adequacy was proved. The developed methods and criteria for evaluating the results of thermogravimetric studies allow us to predict the efficiency of mechanical activation and the calorific value of technical hydrolysis lignin as a component of fuel briquette. At the same time, by varying the compositional composition and technological parameters of briquetting, it is possible to predict the production of fuel briquettes of required quality from wood waste.

Study on Indium Leaching from Indium-Poor Zinc Residue Enhanced by Ultrasonic Treatment

2011 ◽  
Vol 201-203 ◽  
pp. 1770-1773
Author(s):  
Jin Huan Yao ◽  
Xuan Hai Li
Keyword(s):  
Ultrasonic Treatment ◽  
Design Method ◽  
Orthogonal Experiment ◽  
Leaching Rate ◽  
Optimum Conditions ◽  
Range Analysis ◽  
Orthogonal Experiment Design ◽  
Leaching Process ◽  
New Process ◽  
Hcl Solution

In this paper, orthogonal experiment design method was applied to determine the optimum condition for indium leaching from indium-poor zinc residue in HCl solution. Taking the results of range analysis and the situation of industrial production into consideration, the optimum conditions for conventional leaching are: reaction temperature 70°C, concentration of HCl 6 mol/L, leaching time 1.0 h, and ratio of liquid to solid 8:1. Under the optimum conditions, ultrasonic was used to enhance the leaching process. Compared with the conventional leaching process, this new process can provide better indium recovery, shorter leaching time, and faster leaching rate. The indium extraction of indium-poor zinc residue with ultrasonic treatment is up to 96 %, which is 31.0 % higher than that without ultrasonic treatment. In addition, the normal agitation improves the diffusion of solution in the ultrasonically enhanced leaching experiment.

Preparation and Characterization of Activated Carbon Fibers from Jute Fibers by Phosphoric Acid Activation

2012 ◽  
Vol 184-185 ◽  
pp. 1110-1113 ◽  
Author(s):  
Li Fen He ◽  
Qi Xia Liu ◽  
Tao Ji ◽  
Qiang Gao
Keyword(s):  
Activated Carbon ◽  
Carbon Fiber ◽  
Phosphoric Acid ◽  
Carbon Fibers ◽  
Activated Carbon Fibers ◽  
Optimum Conditions ◽  
Activation Time ◽  
Activation Temperature ◽  
Jute Fibers ◽  
Activating Agent

Various jute-based activated carbon fibers were prepared by using jute fibers as raw materials and phosphoric acid as activating agent. The effects of three main factors such as concentration of activating agent, activation temperature and activation time on the yield and adsorptive properties of active carbon fibers were investigated via orthogonal experiments. The surface physical morphology of jute-based activated carbon fiber was also observed by using Scanning Electron Microscope. Results showed that the optimum conditions were phosphoric acid concentration of 4 mol/L, activation temperature of 600 °C and activation time of 1h. The yield, iodine number and amount of methylene blue adsorption of the active carbon fiber prepared under optimum conditions were 37.99 %, 1208.87 mg/g and 374.65 mg/g, respectively.

Experimental Study on Concentrating Scandium by Leaching from Associated Scandium Ore

2013 ◽  
Vol 734-737 ◽  
pp. 1033-1036
Author(s):  
Gui Fang Zhang ◽  
Peng Yan ◽  
Qing Rong Yang
Keyword(s):  
Experimental Study ◽  
Particle Size ◽  
Hydrochloric Acid ◽  
Acid Concentration ◽  
Hydrochloric Acid Concentration ◽  
Leaching Rate ◽  
Optimal Conditions ◽  
Research Results ◽  
Solid Ratio ◽  
Leaching Residue

Based on the benefication of the complex silicate ore containing scandium, the research about aid-leaching agent used in the leaching of the scandium concentrate was been conducted. And the suitable leaching agent and aid-leaching agent which the useful ions entered into leaching liquid and the harmful ions were kept in leaching residue were been found according to the experiment results. For the scandium of sample existed various complex silicate ore as isomorphism form, the research has adopted hydrochloric acid with aid-leaching agent to dissociate the silicate ore and make scandium entering into solution. The research results has shown that the scandium leaching rate could reach 92.06% under the optimal conditions which the hydrochloric acid concentration is 22.8%, the dosage of aid leaching agent is 6%, liquid solid ratio is 4:1, particle size of leaching material totally is less than 0.15mm and leaching time is 8h.

The technical and economic comparison of ethylene production from natural gas and ethane

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Farooq Abubakar Atiku ◽  
Vahid Pirouzfar ◽  
Chia-Hung Su ◽  
Sung-Yen Wei
Keyword(s):  
Natural Gas ◽  
Ethylene Production ◽  
Petrochemical Industry ◽  
Rate Of Return ◽  
Optimal Conditions ◽  
Economic Optimization ◽  
Optimum Conditions ◽  
Investment Cost ◽  
Significant Step ◽  
Economic Comparison

Abstract Ethylene is one of the most primary and widely used petrochemical products in today’s world and is considered as a chemical building block in the petrochemical industry. In this research, ethylene production from ethane and natural gas is evaluated in terms of cost and optimum conditions. Also, a comprehensive economic and technical comparison is made to achieve the optimal conditions for ethylene production concerning feed diversity. Nowadays most ethylene production units run with ethane feed. If it is possible to implement gas-ethylene processes with an inexpensive natural gas feed, it will be a significant step for technical and economic optimization. Thus, some methods are introduced and compared, and finally an economic review about best condition for ethylene production from ethane and natural gas/investment with regard to cost and economic efficiency of the methods is provided. The investment cost for Gas to Ethylene (GTE) and Ethane to Ethylene (ETE) processes is 363–701 million dollars per year, respectively. Also, rate of return (ROR) of 24 and 19% is calculated for GTE and ETE processes, respectively.

scholarly journals Optimal Conditions For Production Acidic D-Xylanase By Aspergillus niger in Submerged Fermentation

2011 ◽  
Vol 5 (3) ◽  
pp. 14-21
Author(s):  
Muhamed Omar Abdulatif ◽  
Hyder H. Assmaeel ◽  
Raghad kadhim Obeid ◽  
Ayat Adnan Abbas
Keyword(s):  
Aspergillus Niger ◽  
Rice Husk ◽  
Enzyme Production ◽  
Inoculum Size ◽  
Optimal Conditions ◽  
Optimum Conditions ◽  
Xylanase Production ◽  
Primary Isolation ◽  
Optimum Ph ◽  
Optimum Period

he Xylanase producing strain Aspergillus niger was isolated from soil on potato dextrose agar in the presence of xylan as its first substrate for primary isolation, and then grown under liquid medium fermentation in the presence of crude xylan (rice husk) to produce D-Xylanase. the optimum conditions were determined as follows: the Optimum pH for xylanase production was found pH 5.0, xylanase was induced by xylan (rice husk) 0.1% and the production was (61.221 U/ml) and nitrogen source Yeast extract recorded highest enzyme production( 89.71 U/ml), and repressed by carbon source xylose the highest enzyme production (88.69 U/ml). The optimum temperature was 40°с for xylanase production was (35.15 U/ml), the optimum period after 7 days of incubation was (52.33 U/ml) ,the optimum substrate concentration 0.1% was (45.95 U/ml), and the optimum inoculum size was 1 x 106 (spore /ml) recorded (57.19 U/ml ).

Chemical Activation of Dicalcium Silicate and its Use for Cement Production

2019 ◽  
Vol 1151 ◽  
pp. 17-21
Author(s):  
Theodor Staněk ◽  
Martin Boháč ◽  
Petr Sulovský
Keyword(s):  
Electron Microscopy ◽  
Calcium Carbonate ◽  
Ordinary Portland Cement ◽  
Chemical Activation ◽  
Tricalcium Silicate ◽  
Dicalcium Silicate ◽  
Technological Parameters ◽  
Short Term ◽  
Cement Production ◽  
Belite Cement

In this work, it was found out that dicalcium silicate doped with SO3 shows higher hydraulic activity compared to pure dicalcium silicate. This finding was used to prepare and optimize high-belite cement from SO3 doped clinkers. The belite cement exhibited the same technological parameters, including short-term strengths, as ordinary Portland cement with a high content of tricalcium silicate. The clinker for belite cement is environmentally and economically advantageous. It is possible to burn the clinker at a temperature of 100 °C lower than conventional clinker and with lower consumption of calcium carbonate. In particular, methods of optical and electron microscopy were used for the research.

scholarly journals Optimization of lead (II) removal in leachates using Moringa oleifera seeds

2019 ◽  
Vol 268 ◽  
pp. 06011
Author(s):  
Mae Ann De Castro ◽  
Cyril Ann Agripa ◽  
John Raymond Barajas ◽  
Faye Taniegra
Keyword(s):  
Low Income ◽  
Moringa Oleifera ◽  
Primary Sources ◽  
Lead Removal ◽  
Optimal Conditions ◽  
Optimum Conditions ◽  
Independent Variables ◽  
Comprehensive Programs ◽  
High Lead ◽  
Percent Removal

The absence of comprehensive programs in regulating release of lead to the environment in growing cities situated in developing countries results to widespread intrusion of lead bioaccumulation in their primary sources of food. As a result, a significant increase in lead related diseases continually grows in many low income regions. In an attempt to provide a means of minimizing lead bioaccumulation, we test the extent to which Moringaoleifera seeds (MOS) removes lead (II) ions in aqueous solution. A box-behnken experimental design was used to obtain the optimal conditions in the lead (II) removal process. MOS dosage, initial lead (II) concentration, and pH were found to have significant effects on the percent removal of lead (II) in solution. Actual values of these independent variables were chosen on the basis of preliminary experimental results. Optimum conditions were found to be: MOS dosage 10.0 g/L, initial lead (II) concentration 20.0 ppm, and pH at 5.5. Lead removal using MOS was also performed at optimal conditions. In conclusion, a high lead (II) removal using MOS strongly suggests its potential to be used as a means of treating liquids highly contaminated with lead.

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