Purification Route of Pyrite from Coal Mining

2016 ◽  
Vol 869 ◽  
pp. 155-158
Author(s):  
Camila Machado de Oliveira ◽  
Adilson Oliveira ◽  
Jeane Almeida do Rosário ◽  
Agenor de Noni Jr. ◽  
Michael Peterson
Keyword(s):  
Solar Cells ◽  
Organic Solvent ◽  
Solid Waste ◽  
Coal Mining ◽  
Sulphuric Acid ◽  
Sulphur Dioxide ◽  
Hot Water ◽  
Soluble Salts ◽  
It Use ◽  
Purity Level

Pyrite, mineral largely found in nature, is considered a solid waste when is obtained from the coal mining. However, can be precursor of products like: sulphur, sulphuric acid, hematite, sulphur dioxide, fertilizers and iron sulfates. Several studies also point it property of semiconduction and it use in solar cells. Increase it purity level is important for transforming it in products with more aggregate value. Thus, the present work suggests a purification route for the reduction in soluble salts in water, organics and quartz associated with pyrite from the coal mining beneficiation. The used methods were solubilization in hot water and in organic solvent (dichloromethane). Were applied XRD, FTIR, total sulphur determination, and gas helium picnometry. Comparing the results obtained for the “in nature” pyrite with the purified one, proved the efficiency of the proposed method.

scholarly journals Modelling and Multi-Objective Optimization of the Sulphur Dioxide Oxidation Process

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1072
Author(s):  
Mohammad Reza Zaker ◽  
Clémence Fauteux-Lefebvre ◽  
Jules Thibault
Keyword(s):  
Sulphuric Acid ◽  
Sulphur Dioxide ◽  
Variable Number ◽  
Inlet Temperature ◽  
Multi Objective Optimization ◽  
Absorption Column ◽  
Maximum Reaction Rate ◽  
Multi Objective ◽  
Maximum Reaction

Sulphuric acid (H2SO4) is one of the most produced chemicals in the world. The critical step of the sulphuric acid production is the oxidation of sulphur dioxide (SO2) to sulphur trioxide (SO3) which takes place in a multi catalytic bed reactor. In this study, a representative kinetic rate equation was rigorously selected to develop a mathematical model to perform the multi-objective optimization (MOO) of the reactor. The objectives of the MOO were the SO2 conversion, SO3 productivity, and catalyst weight, whereas the decisions variables were the inlet temperature and the length of each catalytic bed. MOO studies were performed for various design scenarios involving a variable number of catalytic beds and different reactor configurations. The MOO process was mainly comprised of two steps: (1) the determination of Pareto domain via the determination a large number of non-dominated solutions, and (2) the ranking of the Pareto-optimal solutions based on preferences of a decision maker. Results show that a reactor comprised of four catalytic beds with an intermediate absorption column provides higher SO2 conversion, marginally superior to four catalytic beds without an intermediate SO3 absorption column. Both scenarios are close to the ideal optimum, where the reactor temperature would be adjusted to always be at the maximum reaction rate. Results clearly highlight the compromise existing between conversion, productivity and catalyst weight.

Hot water seed treatment for Leucaena glauca (L.) Benth

1962 ◽  
Vol 2 (6) ◽  
pp. 178 ◽  
Author(s):  
SG Gray
Keyword(s):  
Water Treatment ◽  
Effective Treatment ◽  
Sulphuric Acid ◽  
Seed Treatment ◽  
Hot Water ◽  
Sowing Seed

Seed of Leucaena glauca (L.) Benth. germinates slowly, and irregularly unless treated before sowing to render the testa permeable to water. Treatment with sulphuric acid is effective but inconvenient to use. Experiments with hot water over a range of temperature and time are described. An effective treatment was to immerse the seed in water at 80�Cfor two minutes. After this treatment seed can be dried rapidly and stored before sowing. Seed treated in this way has retained full viability for 15 months.

scholarly journals Morphological Study of Zinc-Oxide Nanorods Grown by Hot Water Treatment Suitable for Solar Cells Conversion Efficiency Enhancement

2020 ◽  
Author(s):  
Mohammad Khairul Basher ◽  
S. M. Shah Riyadh ◽  
Md. Khalid Hossain ◽  
Mahmudul Hassan ◽  
Md. Abdur Rafiq Akand ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Solar Cells ◽  
Water Treatment ◽  
Conversion Efficiency ◽  
Zno Nanorods ◽  
Hot Water ◽  
Zinc Oxide Nanorods ◽  
Hot Water Treatment ◽  
Time Duration ◽  
Zinc Surface

Zinc-oxide (ZnO) nanostructures including nanorods are currently considered as a pioneer research of interest world-wide due to their excellent application potentials in various applied fields especially for the improvement of energy harvesting photovoltaic solar cells (PSC). We report on the growth and morphological properties of zinc-oxide (ZnO) nanorods grown on the surface of plain zinc (non-etched and chemically etched) plates by using a simple, economical, and environment-friendly technique. We apply hot water treatment (HWT) technique to grow the ZnO nanorods and varies the process parameters, such as temperature and the process time duration. The morphological, and elemental analysis confirm the agglomeration of multiple ZnO nanorods with its proper stoichiometry. The obtained nanostructures for different temperatures with different time duration showed the variation in uniformity, density, thickness and nanonorods size. The ZnO nanorods produced on the etched zinc surface were found thicker and uniform as compared to those grown on the non-etched zinc surface. This chemically etched Zinc plates preparation can be an easy solution to grow ZnO nanorods with high density and uniformity suitable for PSC applications such as to enhance the energy conversion efficiency of the photovoltaic (PV) solar cells towards the future sustainable green earth.

scholarly journals PURIFICATION OF INDONESIAN NATURAL GRAPHITE AS CANDIDATE FOR NUCLEAR FUEL MATRIX BY ACID LEACHING METHOD: CHEMICAL CHARACTERIZATION

2020 ◽  
Vol 26 (3) ◽  
Author(s):  
Deni Mustika ◽  
Torowati Torowati ◽  
Arbi Dimyati ◽  
Sudirman Sudirman ◽  
Adel Fisli ◽  
...  
Keyword(s):  
Sulphuric Acid ◽  
Nuclear Fuel ◽  
Hydrofluoric Acid ◽  
Acid Leaching ◽  
Chemical Characterization ◽  
Ash Content ◽  
Natural Graphite ◽  
Nuclear Graphite ◽  
Purity Level ◽  
Graphite Matrix

PURIFICATION OF INDONESIAN NATURAL GRAPHITE AS CANDIDATE FOR NUCLEAR FUEL MATRIX BY ACID LEACHING METHOD: CHEMICAL CHARACTERIZATION. Graphite matrix in Pebble Bed Reactor (PBR) – High Temperature Gas Cooled Reactor (HTGR) has an important role as heat transfer medium, neutron moderator and structural material to protect fuel. Thus, graphite matrix must fulfill chemical and physical characteristics for PBR-HTGR fuel. Indonesia has graphite sources in several regions that can potentially be purified. This research aimed to purify Indonesian natural graphite by several variation of acids and to perform chemical characterizations. Natural graphite from flotation process was purified by several variations of acid, i. e., hydrofluoric acid (HF), sulphuric acid + nitric acid (H2SO4 + HNO3) and hydrofluoric acid + hydrochloric acid + sulphuric acid (HF + HCl + H2SO4) and subsequently followed by chemical characterizations such as purity level, ash content, and boron quivalent. The highest purity was obtained in the purification process by HF with carbon content up to 99.52%; this purity level fulfills the specification of nuclear graphite (>99%). Ash content analysis shows a value in compliance with the specification requirement, i.e., < 100 ppm, and boron equivalent value also fulfills the specification value of < 1 ppm. It can be concluded from this study that the graphite purified by acid leaching with HF can be used as fuel matrix candidate but is qualified as low quality. Futher research is required to produce high quality nuclear graphite, particularly research in the minimization of the impurity by evaporation at temperatures over 950 oC to by far lower the ash content.Keywords:  Indonesian natural graphite, purification, nuclear fuel matrix, acid leaching, chemical characterization.

Influence of Different Pre-sowing Treatments on Germination and Seedling Vigour of Guava (Psedium guajava L.) Seeds

2015 ◽  
Vol 22 (1) ◽  
pp. 7-9
Author(s):  
Poomaruthai Masilamani ◽  
A. Nagaraja ◽  
M. Yadav ◽  
D. Srivastava
Keyword(s):  
Sulphuric Acid ◽  
Hot Water ◽  
Control Treatment ◽  
Seedling Vigour ◽  
Vigour Index ◽  
Index Value ◽  
And Control ◽  
Paper Method

The study aimed at investigating the effect of pre-sowing treatments on the germination and seedling vigour of Guava (Var. Allahabad Safeda) seeds. The pre- sowing treatments were made up cold and hot water soaking, manual scarification with sand paper, electronic scarification, different concentration of sulphuric acid, H2O2, CaOCl2 along with control. The treated and control seeds were placed for germination in top of the paper method. Twenty five days after sowing the result revealed that seeds soaked with CaOCl2 2% for 12 hrs. registered highest germination of 41 per cent followed by seed treated with H2SO4 200ml/kg for 15 minutes (40%). The control seeds gave only 10 per cent germination. Vigour index values shows significant differences among the treatments. The highest vigour index values of 119 were recorded in the seeds treated with H2SO4 200ml/kg for 10 minutes. The lowest vigour index value of 16 was recorded in control treatment. The results showed that treating the seeds with CaOCl2 2% for 12 hrs (or) treated with H2SO4 200ml/kg for 10 (or) 15 minutes was the most effective pre-sowing treatment for the germination and seedling vigour of Guava seeds.

SEED TREATMENT METHODS AND DURATION EFFECTS ON GERMINATION OF WILD SUNFLOWER

2000 ◽  
Vol 36 (1) ◽  
pp. 63-69 ◽  
Author(s):  
J. O. AKINOLA ◽  
A. LARBI ◽  
G. O. FARINU ◽  
A. A. ODUNSI
Keyword(s):  
Hydrogen Peroxide ◽  
Sulphuric Acid ◽  
Seed Treatment ◽  
Lower Cost ◽  
Hot Water ◽  
Environmental Concerns ◽  
Hot Water Treatment ◽  
Tithonia Diversifolia ◽  
Wild Sunflower ◽  
Oven Drying

The effects were evaluated of six methods and six durations of seed treatment on the germination of wild sunflower (Tithonia diversifolia) seeds. The treatments were as follows: (1) hot water at 80 °C, (2) hot water at 100 °C, (3) oven-drying at 80 °C, (4) oven-drying at 100 °C, (5) immersion in concentrated sulphuric acid and (6) immersion in 10% hydrogen peroxide. The durations were 0, 2.5, 5, 10, 15 and 20 min. Treatment with hot water at 80 or 100 °C for 11–14 min, and oven-drying at 100 °C for 20 min all resulted in more than 65% germination 10 d after treatment. Oven-drying at 80 °C, immersion in concentrated sulphuric acid and in 10% hydrogen peroxide resulted in less than 50% germination. Based on the higher cumulative germination, lower cost, and environmental concerns, hot water treatment at 80 or 100 °C for 11–15 min is recommended.

The Research of Compressor Oil Used on Filling Supercritical Sulfur Dioxide

2013 ◽  
Vol 664 ◽  
pp. 789-794
Author(s):  
Zhao Xia Lu ◽  
Zong Yi Tian ◽  
You Cheng Xiao ◽  
Sheng Li ◽  
Cai Zhen Tang ◽  
...  
Keyword(s):  
Sulfur Dioxide ◽  
Working Conditions ◽  
Sulphur Dioxide ◽  
Supercritical Condition ◽  
It Use ◽  
Base Oil ◽  
Performance Requirements ◽  
Lubrication Performance ◽  
Dioctyl Sebacate

According to compressor working conditions and compressor lubrication performance requirements in this paper. It use a polyether and dioctyl sebacate as the base oil, and adding a variety of functions of composite additive deployment, Develop a kind of a compressor oil used on compressing and filling sulphur dioxide (SO2) in the supercritical condition. Experiments show that the developed compressor oil not only meets the performance requirements of compress and filling SO2 in supercritical condition, but also has a very strong adaptability condition.

Mortality and cancer morbidity in workers exposed to sulphur dioxide in a sulphuric acid plant

1988 ◽  
Vol 61 (3) ◽  
pp. 157-162 ◽  
Author(s):  
Viveka Englander ◽  
Allan S�berg ◽  
Lars Hagmar ◽  
Robyn Attewell ◽  
Andrejs Sch�tz ◽  
...  
Keyword(s):  
Sulphuric Acid ◽  
Sulphur Dioxide ◽  
Acid Plant ◽  
Cancer Morbidity
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