Study on Extracting Vanadium from Coal Vanadium Ore

2011 ◽  
Vol 396-398 ◽  
pp. 504-507
Author(s):  
Cheng Xi
Keyword(s):  
Sulphuric Acid ◽  
Room Temperature ◽  
Tap Water ◽  
Size Fraction ◽  
Curing Temperature ◽  
Curing Time ◽  
Test Results ◽  
Leaching Rate ◽  
Solid Ratio ◽  
Sulphuric Acid Concentration

Coal vanadium ore from Hunan was pretreated by sulfuric acid for curing. Influences of curing time, curing temperature, sulphuric acid concentration and ore size fraction on vanadium leaching rate were investigated and discussed. Test results showed that: -100 mesh ore size was cured by 20% added quantity of sulphuric acid at 180°C for 24h and was leached by agitation with tap water, the liquid solid ratio of 4: 1 at room temperature for 12h, vanadium leaching rate was 74%

Transformation Behavior of Molybdenum during Pressure Oxidation Process of Molybdenite Concentrate

2011 ◽  
Vol 79 ◽  
pp. 258-263
Author(s):  
Wang Zhong Mu ◽  
Ting An Zhang ◽  
Guo Zhi Lü ◽  
Zhi He Dou ◽  
Lan Hu ◽  
...  
Keyword(s):  
Sulphuric Acid ◽  
Acid Concentration ◽  
Oxidation Process ◽  
Leaching Rate ◽  
Transformation Behavior ◽  
Pressure Oxidation ◽  
Molybdenite Concentrate ◽  
Solid Ratio ◽  
Sulphuric Acid Concentration ◽  
Single Factor Experiment

MoS2(AR) was used to analyze molybdenum transformation behavior in the pressure oxidation process of Chile molybdenite concentrate. Amount of NaNO3, temperature and sulphuric acid concentration were investigated on the total transform rate of Mo, leaching rate of Mo and absolute transform rate of Mo in residue. ICP, XRF, XRD were used to analyze the content and phase of elements in the molybdenite concentrate and residue. Single factor experiment results of indicate that when amount of NaNO3 is 1:4, temperature is 150°C,sulphuric acid concentration is 40g/L, oxygen partial pressure is 0.8MPa, liquid to solid ratio is 6:1(ml:g), reaction time is 120min and stirring speed is 500rpm, total transform rate of Mo is 97.95%, leaching rate of Mo is 18.48% and absolute transform rate of Mo in residue is 79.47%. Synthetical condition experiment results certified this process has the preferably reproducibility. Molybdenum could be recovered sufficiently through this method.

Effect of Oxidant on the Leaching Rate of Indium from Water Quenching Slag

2013 ◽  
Vol 591 ◽  
pp. 122-125
Author(s):  
Li Jiao Yang ◽  
Si Chen ◽  
Yan Zhang ◽  
Nan Chun Chen ◽  
Jun Gao ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Sulfuric Acid ◽  
Potassium Permanganate ◽  
Crystal Violet ◽  
Acid Leaching ◽  
Water Quenching ◽  
Test Results ◽  
Leaching Rate ◽  
Initial Concentration ◽  
Solid Ratio

Extracting indium from water quenching slag, which contains poor indium, by two process of leaching, the effect of different oxidants and dosages on the leaching rate of indium in water quenching slag were studied. The leaching conditions: temperature 80 °C, leaching time 2 h, the liquid to solid ratio of neutral leaching 8︰1, the liquid to solid ratio of acid leaching 2︰1, initial concentration of sulfuric acid 500 g·L-1, adding different oxidants, the concentration was detected by crystal violet spectrophotometry. Test results showed that the leaching rate of indium was significantly improved by adding hydrogen peroxide and potassium permanganate. Compared with the effect of different oxidants, the effect of potassium permanganate was significantly higher than that of hydrogen peroxide on the leaching rate of indium.

Effect of Curing Regimes on Metakaolin Geopolymer Pastes Produced from Geopolymer Powder

2012 ◽  
Vol 626 ◽  
pp. 931-936 ◽  
Author(s):  
Liew Yun Ming ◽  
Kamarudin Hussin ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Mohammed Binhussain ◽  
Luqman Musa ◽  
...  
Keyword(s):  
Room Temperature ◽  
Raw Materials ◽  
Solidification Process ◽  
Curing Temperature ◽  
Alkali Concentration ◽  
Strength Development ◽  
Curing Time ◽  
Curing Conditions ◽  
Metakaolin Geopolymer ◽  
Geopolymer Paste

The properties of metakaolin geopolymer paste are affected by the alkali concentration, the initial raw materials, solidification process, and amount of mixing water as well as the curing conditions. This study aimed to investigate the effect of curing temperature (room temperature, 40°C, 60°C, 80°C and 100°C) and curing time (6h, 12h, 24h, 48h and 72h) on the geopolymer pastes produced from geopolymer powder. The results showed that curing at room temperature was unfeasible. Heat was required for the geopolymerization process, where strength increased as the curing temperature was increased. Moderate elevated curing temperature favored the strength development of geopolymer pastes in comparison with those treated with extreme elevated curing temperature. When geopolymer paste was subjected to extreme elevated curing temperature, shorter curing time should be used to avoid deterioration in strength gain. Similarly, longer curing time was recommended for moderate elevated curing temperature. The microstructure of geopolymer paste cured at moderate curing temperature showed obvious densification of structure. In contrast, the structure formed was weak and less compact at very high elevated curing temperature.

Study on the Gold Leaching Process by Potassium Ferricyanide

2015 ◽  
Vol 814 ◽  
pp. 273-277
Author(s):  
Ping Tang ◽  
Jing Liu ◽  
Min Wei Song ◽  
Hai Ping Yu ◽  
Xu Zhang
Keyword(s):  
Room Temperature ◽  
Potassium Ferricyanide ◽  
Process Conditions ◽  
Leaching Rate ◽  
Gold Leaching ◽  
Solid Ratio ◽  
Leaching Process ◽  
Refractory Gold ◽  
Object Of Study ◽  
High Arsenic

The traditional gold leaching method is cyanidation, which carries serious security and environmental problems. More and more attention is paid to the research on non-cyanide process. A high-arsenic-and-sulphur refractory gold concentrate in Sichuan was taken as the object of study. After the roasting-oxidation pretreatment of the sample, potassium ferricyanide was adopted to carry on the process experiment on gold-leaching. The leaching results as well as correlative process conditions were both investigated. The results showed that good leaching effects could be achieved by potassium ferricyanide. When the amount of potassium ferricyanide was 60g/L, the concentration of NaOH 0.2mol/L, the liquid-solid ratio 6:1 and the leaching process at room temperature lasted for 20h, the gold leaching rate reached 88.1%. If the leaching aid CaO2 is added simultaneously, it can contribute to the gold leaching. When the amount of CaO2 was 3g/L, the gold leaching rate increased to more than 94%, the amount of potassium ferricyanide decreased to 50g/L and the leaching time reduced to 14h.

Effect of Curing Conditions on the Mechanical Properties of Fly Ash-Based Geopolymer without Sodium Silicate Solution

2014 ◽  
Vol 699 ◽  
pp. 15-19 ◽  
Author(s):  
Rosniza Hanim Abdul Rahim ◽  
Khairun Azizi Azizli ◽  
Zakaria Man ◽  
Muhd Fadhil Nuruddin
Keyword(s):  
Compressive Strength ◽  
Elevated Temperature ◽  
Fly Ash ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Room Temperature ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Curing Temperature ◽  
Curing Time

Geopolymer is associated with the alkali activation of materials rich in Si and Al, and alkali activator such as sodium hydroxide is used for the dissolution of raw material with the addition of sodium silicate solution to increase the dissolution process. However, the trend of strength development of geopolymer using sodium hydroxide alone is not well established. This paper presents an evaluation on compressive strength of fly ash–based geopolymer by varying curing time with respect to different curing temperature using sodium hydroxide as the only activator. The samples were cured at room temperature and at an elevated temperature (60°C). Further analysis on the microstructure of geopolymer products cured at 60°C was carried out using Field Emission Scanning Microscopy (FESEM). It can be observed that the compressive strength increased as the curing time increased when cured at room temperature; whereas at elevated temperature, the strength increased up to a maximum 65.28 MPa at 14 days but gradually decreased at longer curing time. Better compressive strength can be obtained when the geopolymer was cured at an elevated temperature compared to curing at room temperature.

Innovative Process of Leaching of Nickel Supported Activated Carbon in Ammonium Sulfate

2011 ◽  
Vol 201-203 ◽  
pp. 1774-1779
Author(s):  
Ze Biao Zhang ◽  
Wan Kun Wang ◽  
Jin Hui Peng
Keyword(s):  
Activated Carbon ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Normal Pressure ◽  
Leaching Rate ◽  
Initial Concentration ◽  
Comprehensive Utilization ◽  
Solid Ratio ◽  
Innovative Process ◽  
Before And After

The leaching tests of nickel supported activated carbon under normal pressure in (NH4)2SO4were studied. The effects of experimental condition, such as initial concentration of (NH4)2SO4, liquid-to-solid ratio, leaching time and leaching temperature on the leaching rate of nickel, were investigated. The results show that the leaching rate of nickel is 96.12% with initial concentration of (NH4)2SO4of 7.5%, liquid-to-solid ratio of 2, leaching time of 5h and leaching temperature of 25°C. The morphology of nickel supported activated carbon before and after leaching was characterized by XRD, which proved the effective separation of nickel and activated carbon. The leaching rate of nickel was also shown better at room temperature and atmospheric pressure. Moreover, it needn’t equipments enduring high-pressure and high temperature in the leaching process, thus reducing the costs of leaching equipments greatly. This work provides a new way to the comprehensive utilization of nickel-containing activated carbon.

Experimental Investigation of Indium Extraction by Sulfuric Acid Precure Pressure-Atmospheriation Leaching from Tin Dust

2013 ◽  
Vol 634-638 ◽  
pp. 3211-3215
Author(s):  
Yan Jiang ◽  
Gan Xie ◽  
Rui Min Xiao ◽  
Du Shu Huang ◽  
Zi Jing Li ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Sulfuric Acid ◽  
Reaction Time ◽  
Tobacco Smoke ◽  
Initial Temperature ◽  
Curing Time ◽  
Leaching Rate ◽  
Solid Ratio ◽  
Leaching Reaction ◽  
Acid Dosage

Sulfuric Acid precure Pressure-atmospheriation leaching process from tin dust was studied. The factors had been investigated,which effects indium leaching rate,the factors are :the sulfuric acid initial temperature, curing time of heat, acid dosage, leaching reaction time, leaching temperature, the liquid-solid ratio and so on.The results show that the indium, zinc and tin leaching rate can be 96.68%, 97.70% and 0.52%,while pressure-atmospheriation leaching is carried out under the initial temperature 140°C,sulfuric acid, the time of heat aging 40 min, acid dosage and tin of tobacco smoke mass ratio0.7:1, leaching time 1.5h, leaching temperature 90°C,and the liquid-solid ratio 4:1 conditions.

Research on Mechanical Properties of Geopolymer Concrete under early Stage Curing System

2012 ◽  
Vol 164 ◽  
pp. 492-496
Author(s):  
Qing Wang ◽  
Kun Ran ◽  
Zhao Yang Ding ◽  
Lin Ge Qiu
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Room Temperature ◽  
Storage Time ◽  
Early Stage ◽  
Curing Temperature ◽  
Geopolymer Concrete ◽  
Curing Time ◽  
Curing Age

Mechanical properties of geopolymer concrete under early stage curing system were studied. The results showed that at the early stage of curing time, compressive strength was improved significantly with the increasing of curing temperature and curing time. The compressive strength decreased and was close to that of standard curing condition at the age of 28d as the curing age increased. In addition, prolonging the storage time at room temperature before the step of high temperature curing could increase the long-term strength.

Effect of Bentonite Addition on Geopolymer Concrete from Geothermal Silica

2016 ◽  
Vol 841 ◽  
pp. 7-15 ◽  
Author(s):  
Himawan Tri Bayu Murti Petrus ◽  
Joshepine Hulu ◽  
Gede S.P. Dalton ◽  
Elsa Malinda ◽  
Rizal Agung Prakosa
Keyword(s):  
Compressive Strength ◽  
Room Temperature ◽  
Sem Analysis ◽  
Strength Test ◽  
Raw Material ◽  
Curing Temperature ◽  
Curing Time ◽  
Compressive Strength Test ◽  
Temperature Optimization ◽  
Alkaline Activator

Silica scaling is one of major problems in geothermal power plant. Silica recovery is a promising method to solve this particular problem in regard to silica utilization as geopolimer concrete. In this experimental study, bentonite was used as raw alumina source. Experiments were conducted by means observing the geopolymerization through alkaline activator ratio, raw material ratio, and temperature optimization. After mixing and casting for 24 hours, samples were cured at 80°C, 100°C, and 120°C for certain period of time and kept at room temperature for 7 days before compressive strength test. The optimum curing time and temperature gained from this experiment were 120 minutes and 100°C with compressive strength of 29.16 MPa. The development of geopolymer bond and microstructure of samples were then investigated by SEM technique. Scanning electron microscopy (SEM) analysis also showed better improvement in geopolymer layer of concrete sample with increasing curing temperature.

scholarly journals Research of Curing Time and Temperature-Dependent Strengths and Fire Resistance of Geopolymer Foam Coated on an Aluminum Plate

Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 87
Author(s):  
Van Su Le ◽  
Petr Louda
Keyword(s):  
Compressive Strength ◽  
Apparent Density ◽  
Fire Resistance ◽  
Room Temperature ◽  
Sandwich Panels ◽  
Aluminum Plate ◽  
Curing Time ◽  
Test Results ◽  
Mass Ratio ◽  
Temperature Dependent

Geopolymer foam (GF) uses a potassium activator and can be cured at high temperatures, which can improve its mechanical properties. In this study, we attempted to test this hypothesis by comparing the flexural and compressive strength, apparent density and fire resistance of GF. The composition of the GF used in the experiment included a potassium activator, basalt ground fiber and aluminum powder with a mass ratio to the binder of 0.45, 0.3 and 0.015, respectively. The samples were cured at room temperature and at 50, 70, 85 and 105 °C with a curing time of 2, 4, 6, 12 and 24 h. Then, the samples were kept until being tested on the third, seventh, 14th and 28th day. The results showed that the flexural and compressive strength and apparent density improved and stabilized after seven days at 85 °C. Furthermore, the GF exhibited a substantial increase after three days in its flexural strength by 111% and compressive strength by 122.9% at the optimal temperature of 85 °C for 2 h compared to the values at RT after 28 days. The GF had an apparent density of 0.558–0.623 g/cm3 on the 28th day. As a new alternative to aluminum materials, investigating the fire resistance of sandwich panels (an aluminum plate covered with a GF layer) is important for their safe impregnation. Sandwich panels with thicknesses of 10–20 mm were exposed to a gas fire. The test results showed that the sandwich panels had significantly improved fire resistance compared to unprotected panels. The longest fire resistance times for the aluminum plate coated with 20 mm of GF layer thickness was 7500 s. Thus, the GF coated on the aluminum plate exhibited superior fire resistance and a reduced heat transfer rate compared to uncoated panels.

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